WO2012174978A1 - 维生素c二步混菌发酵的菌种改造和过程优化 - Google Patents
维生素c二步混菌发酵的菌种改造和过程优化 Download PDFInfo
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- C—CHEMISTRY; METALLURGY
- C12—BIOCHEMISTRY; BEER; SPIRITS; WINE; VINEGAR; MICROBIOLOGY; ENZYMOLOGY; MUTATION OR GENETIC ENGINEERING
- C12P—FERMENTATION OR ENZYME-USING PROCESSES TO SYNTHESISE A DESIRED CHEMICAL COMPOUND OR COMPOSITION OR TO SEPARATE OPTICAL ISOMERS FROM A RACEMIC MIXTURE
- C12P7/00—Preparation of oxygen-containing organic compounds
- C12P7/40—Preparation of oxygen-containing organic compounds containing a carboxyl group including Peroxycarboxylic acids
- C12P7/58—Aldonic, ketoaldonic or saccharic acids
- C12P7/60—2-Ketogulonic acid
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- C12N1/00—Microorganisms; Compositions thereof; Processes of propagating, maintaining or preserving microorganisms or compositions thereof; Processes of preparing or isolating a composition containing a microorganism; Culture media therefor
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- C12N1/205—Bacterial isolates
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- C12N9/00—Enzymes; Proenzymes; Compositions thereof; Processes for preparing, activating, inhibiting, separating or purifying enzymes
- C12N9/0004—Oxidoreductases (1.)
- C12N9/0006—Oxidoreductases (1.) acting on CH-OH groups as donors (1.1)
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- C12P—FERMENTATION OR ENZYME-USING PROCESSES TO SYNTHESISE A DESIRED CHEMICAL COMPOUND OR COMPOSITION OR TO SEPARATE OPTICAL ISOMERS FROM A RACEMIC MIXTURE
- C12P39/00—Processes involving microorganisms of different genera in the same process, simultaneously
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- C12Q1/00—Measuring or testing processes involving enzymes, nucleic acids or microorganisms; Compositions therefor; Processes of preparing such compositions
- C12Q1/02—Measuring or testing processes involving enzymes, nucleic acids or microorganisms; Compositions therefor; Processes of preparing such compositions involving viable microorganisms
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- C12Q1/00—Measuring or testing processes involving enzymes, nucleic acids or microorganisms; Compositions therefor; Processes of preparing such compositions
- C12Q1/26—Measuring or testing processes involving enzymes, nucleic acids or microorganisms; Compositions therefor; Processes of preparing such compositions involving oxidoreductase
- C12Q1/32—Measuring or testing processes involving enzymes, nucleic acids or microorganisms; Compositions therefor; Processes of preparing such compositions involving oxidoreductase involving dehydrogenase
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N33/00—Investigating or analysing materials by specific methods not covered by groups G01N1/00 - G01N31/00
- G01N33/48—Biological material, e.g. blood, urine; Haemocytometers
- G01N33/50—Chemical analysis of biological material, e.g. blood, urine; Testing involving biospecific ligand binding methods; Immunological testing
- G01N33/82—Chemical analysis of biological material, e.g. blood, urine; Testing involving biospecific ligand binding methods; Immunological testing involving vitamins or their receptors
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- C12R2001/00—Microorganisms ; Processes using microorganisms
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- C12R—INDEXING SCHEME ASSOCIATED WITH SUBCLASSES C12C - C12Q, RELATING TO MICROORGANISMS
- C12R2001/00—Microorganisms ; Processes using microorganisms
- C12R2001/01—Bacteria or Actinomycetales ; using bacteria or Actinomycetales
- C12R2001/07—Bacillus
- C12R2001/11—Bacillus megaterium
Definitions
- the invention belongs to the field of industrial microorganisms.
- the present invention relates to a method for detecting changes in proteins, phospholipid groups, nutrient environments, and small molecule metabolites during the passage of vitamin C industrial production strains.
- the invention also relates to a method for increasing the industrial yield of the precursor 2-keto-L-gulonic acid of vitamin C, comprising the method of evolutionary subculture of mixed bacteria, enhancing the interaction of two bacteria to increase the yield of 2-keto-L-gulonic acid, and Molecular biological genetic modification methods and methods of adding glutathione.
- the present invention also provides quality control indicators for raw corn syrup for fermentation. Background technique
- vitamin C is a highly effective antioxidant, which is involved in the important biosynthesis process of human metabolism and is essential for maintaining nutrients and growth. It also has a wide range of applications in the areas of pharmaceuticals, food and cosmetics.
- the method for producing vitamin C in China is “two-step fermentation method”.
- the first step of fermentation uses black bacillus to convert behenyl alcohol into L-behenylose
- the second step is fermentation of Bacillus megaterium and Gluconobacter oxydans. Fermentation, conversion of hawthorn sugar to the precursor of vitamin C 2-keto-L-gulonic acid.
- Gluconobacter oxydans is an acid-producing bacterium
- Bacillus megaterium is a companion. If Gluconobacter oxydans is used alone, growth is not carried out.
- the communication between them is first transmitted to the intracellular space through the cell membrane that senses the external signal, and a series of signal events, including changes in intracellular proteins and changes in the phospholipid group of the cell membrane, are generated.
- the nutrient environment of the culture fluid is constantly changing, and then transmitted to the cells, resulting in a series of different growth fermentation behaviors. The study and determination of these changes will provide useful information for revealing the mechanisms by which subcultures enhance the interaction of two bacteria to promote acid production, and provide support for further optimization of the production process.
- the fermented raw corn syrup also has a great influence on the fermented product.
- Corn syrup is a by-product obtained during the impregnation of corn during the production of corn starch. It contains a variety of nutrients such as amino acids, organic acids, soluble sugars, vitamins and metal salts. It is an important raw material in the production of antibiotics and other media, providing a natural source of organic nitrogen for microbial growth. Due to its low price and rich nutrition, it is widely used in industrial microbial fermentation. Application. The existing technical quality testing methods for corn syrup are prescribed by each manufacturer and there is no national uniform standard.
- a first aspect of the invention provides a method for increasing the yield of 2-keto-L-gulonic acid by subculture of mixed bacteria, comprising the steps of:
- the Bacillus megaterium and Gluconobacter oxydans cultured in step (1) were separately transferred to seed medium at 28-35.
- C 200-280 r / min shaker shaking culture, 24h-48h, obtaining Bacillus megaterium seed solution and Gluconobacter oxydans seed solution;
- the subcultured mixed strain obtained in the step (2) is streaked and purified, and then inoculated on a solid medium, and cultured at 28-35 e C for 24-48 hours; and then transferred to a seed medium at 28-35.
- C 200-280 r / min shaker shaking culture for 24h-48h, the evolution of the Bacillus megaterus seed solution and the evolved Gluconobacter oxydans seed solution;
- the solid medium is prepared by weighing: 10-50 g of L-xanthine, 2-10 g of corn syrup, 2-10 g of beef bone, 2-10 g of yeast dip powder, 0.5-5 g of urea, 2-12 g of peptone, agar 10-50g, KH 2 PO 4 0.5-5g, MgSO 4 0.1-0.7g, CaCO 3 0.5-5g, add water to 1L, adjusted to pH 6.5-7.0, 121. C was sterilized for 20 min to prepare a solid medium.
- the solid medium was prepared by weighing: 20 g of L-xanthine, 3 g of corn syrup, 3 g of beef bone, 3 g of yeast dipping powder, urea lg, peptone 10 g , agar 20 g , KH 2 P0 4 lg, MgSO 4 0.2 g, CaC0 3 lg, water was added to 1 L, pH was adjusted to 6.8, and sterilized at 121 ° C for 20 min to prepare a solid medium.
- the seed culture medium is prepared as follows: Weigh 10-50 g of L-xanthine, 2-10 g of corn syrup, 2-10 g of beef bone, 2-10 g of yeast dip powder, 0.5-5 g of urea, 2-12 g of peptone, KH 2 PO 4 0.5-5g, MgSO 4 0.1-0.7g, CaCO 3 0.5-5g, add water to 1L, adjusted to pH 6.5-7.0, 121. C was sterilized for 20 min to prepare a seed medium.
- Preferred prepared seed medium is: Weigh scale mountain Qian L- sugar 20g, corn syrup 3 g, beef bone 3 g, yeast extract 3 g, urea lg, peptone 10 g, KH 2 P0 4 l g, MgSO 4 0.2 g, CaCO 3 lg, water was added to 1 L, and the pH was adjusted to 6.8, 121. C was sterilized for 20 min to prepare a seed medium.
- the fermentation medium is prepared as follows: L-xanthose 40-120g, corn syrup is weighed proportionally 10-50 g, urea 10-25 g, KH 2 PO 4 0.5-3 g, MgSO 4 0.2-1.2 g, CaCO 3 0.5-5 g Water was added to 1 L, and the pH was adjusted to 6.5-7.5, 121. C was sterilized for 20 min to prepare a fermentation medium.
- the preparation of the fermentation medium is preferably: weigh 80 g of L-wheat sugar, 20 g of corn syrup, 12 g of urea, 12 g of urea, KH 2 P0 4 lg, MgSO 4 0.5 g, CaC0 3 lg, add water to 1 L, adjust the pH to 7.0. , 121. C was sterilized for 20 min to prepare a fermentation medium.
- a second aspect of the invention provides a method of enhancing the interaction of two bacteria to increase the yield of 2-keto-L-gulonic acid, comprising the steps of:
- the Bacillus megaterium and Gluconobacter oxydans cultured in step (1) were separately transferred to seed medium at 28-35.
- C 200-280 r / min shaker shaking culture, 24h-48h, obtaining Bacillus megaterium seed solution and Gluconobacter oxydans seed solution;
- the subcultured mixed strain obtained in the step (2) is streaked and purified, and then inoculated on a solid medium, and cultured at 28-35 e C for 24-48 hours; and then transferred to a seed medium at 28-35.
- C 200-280 r / min shaker shaking culture for 24h-48h, the evolution of the Bacillus megaterus seed solution and the evolved Gluconobacter oxydans seed solution;
- the evolved Bacillus megaterium and the evolved Gluconobacter oxydans were inoculated into a fermentation medium, and the density of the evolved Bacillus megaterium was 2 ⁇ 10 7 -2 ⁇ 10 10 cfu/ml, and the evolved oxidized glucose was obtained.
- the density of the bacillus is xloS xloUcfu/ml, at 28-35.
- C 200-280 r/min shaker shaking culture for 72h-96h, obtaining 2-keto-L-gulonic acid or inoculating the original Bacillus megaterium and evolved Gluconobacter oxydans into the fermentation medium, so that The density of B.
- megaterium was 2xl0 7 -2> ⁇ 10 1() cfu/ml
- density of the evolved Gluconobacter oxydans was 2x10 7 -2xl 9 cfu/ml at 28-35.
- C 200-280 r / min shaker shaking culture for 72h-96h, to obtain 2-keto-L-gulonic acid.
- the solid medium is prepared by weighing: 10-50 g of L-xanthine, 2-10 g of corn syrup, 2-10 g of beef bone, 2-10 g of yeast dip powder, 0.5-5 g of urea, 2-12 g of peptone, agar 10-50g, KH 2 PO 4 0.5-5g, MgSO 4 0.1-0.7g, CaCO 3 0.5-5g, add water to 1L, adjusted to pH 6.5-7.0, 121. C was sterilized for 20 min to prepare a solid medium.
- the solid medium was prepared by weighing: 20 g of L-xanthine, 3 g of corn syrup, 3 g of beef bone, 3 g of yeast dipping powder, urea lg, peptone 10 g , agar 20 g , KH 2 P0 4 lg, MgSO 4 0.2 g, CaC0 3 lg, water was added to 1 L, pH was adjusted to 6.8, and sterilized at 121 ° C for 20 min to prepare a solid medium.
- the seed medium is prepared as follows: 10-50 g of L-xanthine, 2-10 g of corn syrup, 2-10 g of beef bone, 2-10 g of yeast dip powder, 0.5-5 g of urea, and 2-12 g of peptone. KH 2 PO 4 0.5-5g, MgSO 4 0.1-0.7g, CaCO 3 0.5-5g, add water to 1L, adjusted to pH 6.5-7.0, 121. C was sterilized for 20 min to prepare a seed medium.
- Preferred prepared seed medium is: Weigh scale mountain Qian L- sugar 20g, corn syrup 3 g, beef bone 3 g, yeast extract 3 g, urea lg, peptone 10 g, KH 2 P0 4 l g, MgSO 4 0.2 g, CaCO 3 lg, water was added to 1 L, and the pH was adjusted to 6.8, 121. C was sterilized for 20 min to prepare a seed medium.
- the fermentation medium is prepared as follows: 40-120 g of L-xanthose, 10-50 g of corn syrup, 10-25 g of urea, KH 2 PO 4 0.5-3 g, MgSO 4 0.2-1.2 g, CaCO 3 0.5-5 g Add water to 1 L and adjust the pH to 6.5 - 7.5, 121. C was sterilized for 20 min to prepare a fermentation medium.
- the preparation of the fermentation medium is preferably: weigh 80 g of L-wheat sugar, 20 g of corn syrup, 12 g of urea, 12 g of urea, KH 2 P0 4 lg, MgSO 4 0.5 g, CaC0 3 lg, add water to 1 L, adjust the pH to 7.0. , 121. C was sterilized for 20 min to prepare a fermentation medium.
- a third aspect of the invention provides a method for detecting changes in different algebraic proteins of a vitamin C industrial mixed strain, comprising the steps of:
- the Bacillus megaterium and Gluconobacter oxydans cultured in the step (1) 1 were separately transferred to a seed medium at 28-35.
- C 200-280 r / min shaker shaking culture for 24h-48h, obtaining Bacillus megaterium seed solution and Gluconobacter oxydans seed solution;
- the 3-4 samples of the mixed cells obtained in the step (1) 2 were streaked and separately inoculated on a solid medium, 28-35.
- the evolved Bacillus megaterium and the evolved Gluconobacter oxydans obtained in the step (1) 3 were inoculated separately into the seed culture medium, and the density of the evolved Bacillus megaterium was 2 ⁇ 10 7 -2 ⁇ 10 W CFU/mL, and evolved.
- the density of Gluconobacter oxydans is 2x10 8 -2 x 10 n CFU / mL, at 28-35. C, 200-280 r / min shaker shaking culture for 10-15h;
- each 80-100mg is placed in a centrifuge tube, add 0.5 ⁇ 1mL cell lysate to each tube, mix well, intermittent ultrasonic sonication on ice for 20 ⁇ 50s; add 5 ⁇ 15 ⁇ mass ratio is 2 ⁇ 4 :1
- C to stand the reaction for 10 ⁇ 30min; add 5 ⁇ 15 ⁇ 80 ⁇ 120mM benzyl sulfonyl isopropyl alcohol solution, 4 .
- C is allowed to stand for l ⁇ 3h; centrifuge at 15000rpm for 25 ⁇ 40min; take the supernatant to obtain protein solution;
- the cell lysate is: 8 mol-L 1 urea, 4% by mass of 3-[(3-cholamidopropyl)-diethylamine]-propanesulfonic acid, 40 mM Tris, the balance being water ;
- the bovine serum albumin was added to the Coomassie Brilliant Blue G-250 solution from a low concentration to a high concentration using a Bradford kit, and the absorbance at 595 nm of each protein solution obtained in the step (2) 2 was determined to establish a standard curve; The concentration of the solution protein;
- Step (2) were taken protein containing 50-100 ⁇ ⁇ 2 respective protein solution obtained, was added to each 4 to 6 volumes of -20.
- C ⁇ -40. C acetone, at -20.
- C ⁇ -40. Place under the conditions of C for 12 ⁇ 20h; centrifuge, discard the supernatant, and use -20 for precipitation.
- C ⁇ -40. Washing with a volumetric concentration of C of 70%-85% in acetone; drying to obtain a dry protein powder;
- the two groups of the mixture obtained in (2)7 were subjected to Q-Tof mass identification to obtain a protein spectrum, and differentially expressed proteins of each mixed group sample were obtained by quantitative determination;
- the candidate differential protein content obtained in step (3) is plotted according to time series, and the regularity of these protein changes is observed and analyzed, and then the mixed culture evolution culture is found to improve the production of 2-keto-L-gulonic acid by Gluconobacter oxydans. The role.
- a fourth aspect of the invention provides a method of analyzing a change in a phospholipid group during the passage of a vitamin C producing strain, comprising the steps of:
- the Bacillus megaterium and the Gluconobacter oxydans cultured in the step (1) are respectively transferred into a seed culture medium, and shake cultured at 28-35 ° C, shaking at 200-280 rpm for 24 h to 48 h to obtain a Bacillus megaterus seed solution and Gluconobacter oxydans seed solution;
- the Bacillus megaterium and Gluconobacter oxydans was inoculated into a new seed medium, the density of the Bacillus megaterium is 2xl0 7 -2xl0 10 cfu / mL, so that the density of Gluconobacter oxydans 2xl0 8 _2xlO u cfu / mL, Shake the culture at 28-35 ° C, shaking at 200-280 rpm, using 24h-48h as the passage cycle, and inserting the new seed medium with the volume ratio of 1%-10% for passage, passaging for 100-150 days, 0-100 or 0-150 days to choose 3-5 ⁇ time to take 3-5 samples;
- the 3-5 subculture strains obtained in the step (2) are streaked and purified, and then inoculated on a solid medium, cultured at 28-35 ° C for 24 h to 48 h; and then transferred to the seed medium, respectively.
- the cultured Bacillus megaterium seed solution and the evolved Gluconobacter oxydans seed solution were obtained by shaking culture at 28-35 ° C, shaking at 200-280 rpm for 24 h_48 h;
- the evolved Bacillus megaterium, the evolved Gluconobacter oxydans, and the mixed evolved Bacillus megaterium and the evolved Gluconobacter oxydans were respectively inoculated into a fermentation medium to make the evolved Bacillus megaterium Density is 2 ⁇ 10 7 -2 ⁇ 10 1 ⁇ Cfu/mL, the density of the evolved Gluconobacter oxydans is 2X108-2X10 11 cfu/mL, and shaken at 28-35 ° C, shaking at 200-280 rpm for 10 h-15 h;
- step 2 The cells obtained in step 1 are made into a dry powder, and 200-300 mg of cell dry powder is weighed, placed in a centrifuge tube A, and added with 0.5-0.8 mL of ultrapure water, and thoroughly mixed;
- step 3 Repeat step 3 2-4 times until the cells are completely settled
- the total phospholipid extraction mixture is dissolved in 0.2-2 mL of the stock solution to prepare a sample, and stored at -40 ° C or below;
- the phospholipid standard is added to the sample, so that the final concentration of the phospholipid standard is 0.5-1.5 g / mL;
- the extract is a chloroform/methanol solution containing dibutylhydroxytoluene, the volume ratio of the chloroform/methanol is 1-2:1, and the mass fraction of the dibutylhydroxytoluene is 0.005-0.01%;
- the storage solution is a chloroform/methanol solution containing dibutylhydroxytoluene, the volume ratio of the chloroform/methanol is 1-4:1, and the mass fraction of the dibutylhydroxytoluene is 0.005-0.01%;
- the sample containing the phospholipid standard obtained in the step (5) was tested by LC-MS to obtain the molecular structure and content data of the phospholipid group in the passage process of the vitamin C producing strain;
- the molecular weight data of the phospholipid group of the vitamin C producing strain obtained in the step (6) were subjected to multivariate statistical analysis to obtain differential phospholipid molecular markers for distinguishing the vitamin C producing strains of different passage times;
- the content of the differential phospholipid molecular markers obtained in step (7) is plotted according to different passage times, and the changes of these brick lipid molecules are observed and analyzed, and the phospholipid molecules which play a key role in the subculture process of mixed bacteria and related are found.
- the metabolic pathway provides direction for strain modification and optimization of culture conditions for the purpose of improving 2-keto-L-gulonic acid.
- the method of making the cells into a dry powder is preferably grinding the cells in a mortar using liquid nitrogen.
- the distillation in the step (5) 7 is preferably a vacuum distillation at 30 to 40 °C.
- the phospholipid standard is at least two of phosphatidylglycerol, phosphatidylethanolamine, hemolytic phosphatidylethanolamine, and phosphatidic acid.
- the phosphatidylglycerol, phosphatidylethanolamine, hemolytic phosphatidylethanolamine or phospholipid has a fatty acid hydrophobic tail length of from 10 to 20 carbon atoms per strip.
- the LC-MS detection conditions are preferably:
- Injection volume 10 ⁇ ;
- Mobile phase A (%): chloroform (89.5), methanol (10), ammonium hydroxide (0.5); mobile phase B (%): chloroform (55), methanol (39), ammonium hydroxide (0.5), water ( 5.5);
- Ionization mode ESI (negative ion mode);
- Ion source temperature 100 ° C;
- Desolvent gas flow 400 L/Hr;
- Inlet/outlet energy 50;
- HM1/LM1/HM2/LM2 15.0;
- the multivariate statistical analysis method performs principal component analysis after Pareto pretreatment.
- the invention provides a method for analyzing the changes of phospholipid groups in the process of vitamin C production strains, which involves the extraction and analysis of total phospholipids of cells, and the multi-statistical method for analyzing the obtained phospholipidomics data through the vitamins of different passage numbers.
- the qualitative and quantitative analysis of the phospholipid molecules of the C-producing strains under separate and mixed culture conditions, respectively, and the analysis of phospholipid molecules and metabolic pathways associated with enhancing the interaction between the two strains of vitamin C production strains provide a method for improving 2-ketone It is of great significance to modify the strains and optimize the culture conditions for the purpose of basal-L-gulonic acid.
- a fifth aspect of the invention provides a method for detecting a change in a nutrient environment during the passage of a vitamin C producing strain, comprising the steps of:
- the Bacillus megaterium and Gluconobacter oxydans cultured in the step (1) 1 were separately transferred to a seed medium at 28-35.
- the 3-4 samples of the mixed cells obtained in the step (1) 2 were streaked and purified, and then inoculated separately on a solid medium, 28-35.
- the Bacillus megaterium and Gluconobacter oxydans obtained in the step (1) 3 and the mixed bacteria in which the two bacteria are mixed together are inoculated into a new seed medium, so that the density of Bacillus megaterium is 2 ⁇ 10 7 -2 ⁇ 10 10
- the density of CFU/mL, Gluconobacter oxydans is 2xl0 8 -2xl n n CFU/mL, at 28-35.
- step (2) obtained filtrate 10-50 in a centrifuge tube, add 50-200 ⁇ , 0.04-0.14 mg / ml ⁇ mark succinic acid methanol solution as an internal standard, freeze-dry; add 40-100 A pyridine solution of methoxyamine hydrochloride at a concentration of 20 mg/mL was at 30. C-40.
- the hydration reaction in a C water bath is 60-120 min; and 50-100 LN-methyl-N-trimethylsilane trifluoroacetamide is added to 35.
- C -40 C water bath for silanization reaction 30-60 min;
- the sample obtained in step (2) 2 is introduced into the gas phase color, and the color column is For DB-5MS, the color column has a specification of 30 mx 0.25 mm id and an inlet temperature of 250. C-280.
- the carrier gas is high-purity helium
- the flow rate is 0.6-0.8ml/min
- the split ratio is 3: 1-20: 1.
- the temperature rise program of the column oven is: initial 50. C-80. C, hold 2 min-5 min, 4 ° C / min -8. The speed of C/min rose to 260. C-300.
- EI ionization source source temperature 230 °C-260 °C, detector voltage 2300 V-2700V, ionization voltage 60 eV-80 eV, current 30 ⁇ -50 ⁇ ; quality transfer detection Range 50-800 m/z; Identification of nutrient environmental substances using the NIST 2005 database, quality data processing and relative determination of nutrient environmental substances using Masslynx 4.1 software; and by integrating the peak area of the chromatogram, and with the internal standard The peak area is controlled to obtain the relative content of nutrient environmental substances;
- the relative content of the differential nutrient environmental markers was plotted according to different passage times. The changes of these substances were observed and analyzed, and the changes of nutrient environment during the passage of vitamin C production strains were detected.
- a sixth aspect of the invention provides an assay for detecting a vitamin C producing strain
- a method for small molecule metabolite changes during subculture comprising the following steps:
- Gluconobacter oxydans stored in a glycerin aqueous solution having a volume concentration of 15-30% and Bacillus megaterium deposited in a lactic acid aqueous solution having a volume concentration of 15-30% were inoculated into solid culture respectively.
- the Bacillus megaterium and Gluconobacter oxydans cultured in the step (1) 1 were respectively transferred into a seed culture medium, and shake cultured at 28-35, 200-280 rpm for 24 to 48 hours, respectively, to obtain a Bacillus megaterus seed solution and Gluconobacter oxydans seed solution;
- the 3-5 samples of the mixed cells obtained in the step (1) 2 are streaked and purified, and then inoculated on a solid medium, and cultured in 28-35 for 24-48 hours; and then transferred to a new seed medium, respectively.
- the evolved Bacillus megaterium seed solution and Gluconobacter oxydans seed solution were separately obtained; and stored in a glycerin aqueous solution having a volume concentration of 15-30%;
- the evolved Bacillus megaterium and Gluconobacter oxydans obtained in the step (1) 3 and the mixed bacteria in which the two bacteria are mixed together are inoculated into a new seed medium.
- the density of the evolved Bacillus megaterium is xlO ⁇ xli ⁇ CFU/mL
- the density of the evolved Gluconobacter oxydans is 2x10 8 -2x10 n CFU/mL, shaking at 28-35, 200-280 rpm shaker. Cultivate for 10-15 h;
- the cells obtained in the step (2) 1 are made into a dry powder, and 30-60 mg of the cell dry powder are weighed, respectively, placed in three centrifuge tubes, and then 0.5-1.5 mL of the extract is added, and the concentration of 30-70 ⁇ is 0.020-0.060.
- step (2) 2 to obtain three centrifuge tubes, respectively, add 40-100 concentration of 10-30 mg / mL of methamine hydrochloride pyridine solution in a water bath "chemical reaction 60-120 mill; then join 50-100 ⁇ ⁇ -methyl- ⁇ -trimethylsilane trifluoroacetamide in a 35-40 water bath for silanization reaction 30-60 min;
- the extract is an aqueous methanol solution having a volume fraction of 50-70%;
- the sample obtained in step (2)3 is introduced into the gas phase color, the color transfer column is DB-5MS, the color column is 3 m ⁇ ⁇ 30 m 0.25 mm id, the inlet temperature is ISO -ISOX , carrier gas For high purity helium, constant pressure 80-100KPa, split ratio 3: 1-20: 1, column oven heating procedure is: initial ⁇ - ⁇ , hold 3 min-6 min, to 4* ⁇ /min-S / Min rises to ⁇ ⁇ for 3 min-8 min, using EI ionization source, source temperature 230* ⁇ -260 ⁇ ⁇ , detector voltage 2300 V-2700V, ionization voltage 60 eV-80 eV, current 30 ⁇ - 50 ⁇ ; mass transfer detection range 50-800 m/z; small molecule Metabolite identification was performed using the NIST 2005 database, mass spectrometry data processing and metabolite relative content determination using Masslynx 4.1 software; and by integrating the color peak area and comparing with the peak area of the
- the content of small molecule metabolite markers was graphed according to different passage times, and the changes of small molecule metabolite markers were observed and analyzed, and the changes of intracellular small molecule metabolites during the passage of vitamin C producing strains were detected.
- the method in which the cells are made into a dry powder is liquid nitrogen-milled cells.
- the seventh aspect of the present invention provides a method for transforming Gluconobacter oxydans by metabolic engineering, increasing the copy number of the kaempferol dehydrogenase gene, and improving the fermentation of Gluconobacter oxydans and Bacillus megaterium to transform L-mountain
- the method in which the sugar is a property of 2-keto-L-gulonic acid It includes the following steps:
- the bacterial genome extraction kit was used to extract the genome of Gluconobacter oxydans; the genomic solution 1 ⁇ 1, 5xFastPfu buffer 4 ⁇ 1, 20mM dNTP 2 ⁇ 1, 20 ⁇ primer 1 0 ⁇ 4 ⁇ 1, 20 ⁇ primer 2 0 ⁇ 4 ⁇ 1, sterile water 11.8 ⁇ 1 , FastPfu enzyme 0.4 ⁇ 1, mixed evenly in the PCR tube; PCR tube; ⁇ PCR instrument for amplification cycle, the amplification procedure is: 95. C 2min; 95 ° C 20s, 55 ° C 35s, 72 ° C 2min, a total of 25 cycles; 72. C 5min; 4. C 30min.
- the PCR product was subjected to agarose gel electrophoresis, and the PCR product strip was excised, and the PCR was purified by agarose gel recovery kit. Amplification product.
- the sequence of the primer 1 is: 5,-CCCAAGCTTGACTGGCAGCAGCGCAAC-3'
- the sequence of the primer 2 is: 5,- CGCGGATCCCCGTGATAGCGGCACATGTC-3'
- step (1) Take the PCR amplification product solution obtained in step (1) 8 ⁇ 1, and mix it evenly with ⁇ lOxdigest buffer, 0.5 ⁇ 1 Hindlll enzyme, 0.5 ⁇ 1 BamHI enzyme, at 37.
- the digestion reaction was carried out for 2 hours under C conditions; the product after the reaction was subjected to agarose gel electrophoresis, and the cut product strip was excised, and the PCR product was purified by agarose gel recovery kit.
- the enzyme digestion reaction was carried out for 2 hours under C conditions; the product after the reaction was subjected to agarose gel electrophoresis, and the cut product strip was excised, and the vector product was purified by agarose gel recovery kit.
- the PCR product was subjected to digestion with 5.5 ⁇ l, and the product was digested with 3 ⁇ l, lOxligase buffer ⁇ , DNA ligase 0.5 ⁇ l, and mixed uniformly at 22.
- the ligation reaction was carried out for 30 min under C conditions.
- the ligation product was transformed into Escherichia coli DH5a by chemical transformation, and applied to an antibiotic-containing LB solid medium, and cultured at 37 ° C for 12 h. The single colonies obtained after the culture were in LB liquid medium 37 .
- the plasmid was extracted with a plasmid extraction kit to obtain a gene encoding the kaempferol dehydrogenase gene.
- Gluconobacter oxidans was coated on solid medium at 30. Incubate for 48 hours under C conditions; wash the cells with 2 ml of sterile water, and ice bath for 10 min, 4. C, centrifuge at 5 rpm for 5 min, collect the cells, wash once with pre-cooled sterile water, wash twice with 10% glycerol, resuspend the cells with ⁇ 10% glycerol; and obtain the kaempferol dehydrogenase gene vector obtained from step (2).
- the aqueous solution is uniformly mixed in an electric rotor, ice bath for 5 minutes, and the electric cup is turned Place the 1800V electric shock in the electro-rotator; mix the electric shock product with 900 ⁇ 1 seed medium, at 30.
- the solid medium is: L-mountain 20 g , corn syrup 3 g , beef bone 3 g , yeast dip powder 3 g, urea lg, peptone 10 g, agar 20 g, KH 2 PO 4 lg, MgSO 4 0.2 g, CaC0 3 lg, add water to 1L, adjust pH to 6.8, 121. C sterilized for 20 min.
- the seed medium is: L-mountain 20 g , corn syrup 3 g , beef bone 3 g , yeast dipping powder 3 g, urea lg, peptone 10 g, KH 2 P0 4 lg, MgSO 4 0.2 g, CaC0 3 lg Add water to 1L and adjust pH to 6.8, 121. C sterilized for 20 min.
- the Gluconobacter oxydans and Bacillus megaterium containing the vector encoding the kaempferol dehydrogenase gene obtained in the step (3) are inoculated into a fermentation medium to obtain Gluconobacter oxydans containing a gene encoding a kaempferol dehydrogenase gene.
- the density is 4x10 8 cfu/ml
- the density of Bacillus megaterium is 4x10 8 cfu/ml at 30.
- C cultured at 250 rpm for 120 h to obtain 2-keto-L-gulonic acid.
- the fermentation medium is: 80 g of L-wheat sugar, 20 g of corn syrup, 12 g of urea, 12 g of urea, KH 2 P0 4 lg, MgSO 4 0.5 g, CaC0 3 lg, water to 1 L, pH adjusted to 7.0, 121. C sterilized for 20 min.
- the method can improve the sugar acid conversion rate of 2-keto-L-gulonic acid produced by the fermentation of G. oxidans and Bacillus megaterium.
- An eighth aspect of the invention relates to a method for detecting glutathione for increasing intracellular protein changes during the production of 2-keto-L-gulonic acid by Gluconobacter oxydans, comprising the steps of: (1) determination of intracellular proteins: 1 cell collection and quenching:
- i L fermentation medium A is: 80 gL 1 hawthorn sugar, 20 gL 1 corn syrup, 1 g * L 1 KH 2 P0 4 , 0.2 g * L 1 MgS0 4 , ⁇ 12 g * L 1 urea, balance For water;
- i L fermentation medium B is: 80 gL 1 hawthorn sugar, 20 gL 1 corn syrup, 1 gL 1 KH 2 P0 4 , 0.2 gL 1 MgS0 4 , and 12 g*L 1 urea, 0.8 ⁇ 1.5 mg*mL 1 glutathione, the balance is water;
- step 1 Take the crushed cells obtained in step 1. Place 100 ⁇ 200mg each in a centrifuge tube, add 0.5 ⁇ 2ml cell lysate to each tube, mix well, and sonicly break on ice for 20 ⁇ 50s; add 5 ⁇ 15 ⁇ mass ratio 2 ⁇ 4:1 DNase I / RNaseA enzyme mixed solution, mix, 4. C to stand the reaction for 10 ⁇ 30min; add 5 ⁇ 15 ⁇ 80 ⁇ 120mM phenylmethylsulfonyl isopropanol solution, 4 .
- the bovine serum albumin was added to the Coomassie Brilliant Blue G-250 solution from a low concentration to a high concentration using a Bradford kit.
- the absorbance at 595 nm of each protein solution obtained in Step 2 was determined to establish a standard curve; the protein of each protein solution was determined. concentration;
- the solution obtained in the step solution 6 is mixed to obtain 3-5 parts of the mixed solution, and each mixed solution includes the labeled protein which is obtained by the fermentation of the crushed cells after the fermentation for 1 h from the medium A, and then after the steps 2-6.
- the quenched broken cells were collected from the medium A for 15 h, and the labeled proteins obtained after the steps 2-6 were collected, and the quenched broken cells were collected from the medium B for 1 h to collect the labeled cells after the steps 2-6.
- Protein and from medium B The labeled protein obtained after the step 2-6 was collected from the quenched broken cells for 15 h; C save;
- the mixed solution obtained in 7 was subjected to Q-Tof mass identification to obtain a protein spectrum, and differentially expressed proteins of each mixed group sample were obtained by quantitative determination;
- step (1)8 Principal component analysis is performed to obtain data categories with different variation rules, and candidate differential proteins are obtained;
- the candidate differential protein content obtained in step (2) was plotted according to time series, and the regularity of these protein changes was observed and analyzed, and then glutathione was found to increase the production of 2-keto-L-gulonic acid by Gluconobacter oxydans. The role.
- a ninth aspect of the invention relates to a method for finding a quality control index for a raw material corn syrup for fermentation, which comprises the steps of:
- 0.5-2 g of the uniform raw corn syrup for fermentation is placed in a centrifuge tube, and the supernatant is collected by centrifugation; the obtained supernatant is diluted with ultrapure water 10-40 times, and 10-4 ( ⁇ L is placed in another In a centrifuge tube, add 30-50 ⁇ of 0.040 mg/mL yttrium-labeled succinic acid methanol.
- the solution was an internal standard; after lyophilization, 50-100 ⁇ l of a pyridine solution of methoxyamine hydrochloride at a concentration of 20 mg/mL was added at 30. C-40.
- the hydration reaction in a C water bath was carried out for 60-120 min; 60-100 ⁇ -methyl-N-trimethylsulfonyl trifluoroacetamide was further added at 35. C-40.
- the silencing reaction of the C7j bath is carried out for 20-50 min;
- the sample obtained in step 1 was fed to a gas chromatograph of DB-5MS having a specification of 30 mx 0.25 mm i.d. and an inlet temperature of 250. C-280.
- the carrier gas is high-purity helium
- the flow rate is 0.6-0.8ml/min
- the split ratio is 30: 1-10: 1
- the column temperature riser is: initial 50.
- C is kept for 2-5min, to 4.
- the method uses high-throughput high-resolution detection technology to simultaneously measure corn syrup
- the various chemical components are simple and easy to process. After repeated batches of raw materials, the repeatability is good.
- the method has high resolution and sensitivity, good reproducibility and stability, and the partial least squares discriminant analysis method can quickly and effectively select high-throughput data to distinguish chemical substances of different batches of raw materials and find corn.
- the nine chemicals in the pulp such as glucose, lactic acid, proline, phosphoric acid, galactose, alanine, fructose, 5-ketoproline, and sucrose, can be considered as quality control indicators for corn syrup, which is the current corn syrup. A supplement to the quality check.
- Figure 1 is a graph showing the change in conversion of 2-keto-L-gulonic acid during passaging according to the first aspect of the present invention.
- ⁇ 2-keto-L-gulonic acid conversion.
- Fig. 2 is a graph showing the results of strain fermentation after 50 days of passage according to the first aspect of the present invention.
- Fig. 3 is a graph showing the results of cross-matching fermentation of strains after 100 days of passaging according to the second aspect of the present invention.
- Figure 4 is a cross-column fermentation result of strains after passage for 150 days in accordance with the second aspect of the present invention.
- Figure 5 is a cluster analysis of Gluconobacter oxydans protein of subculture 0, 50, 100, 150 passages according to the third aspect of the present invention.
- Figure 6 is a graph showing the relative expression level of intracellular hawthorn/behenone dehydrogenase in Gluconobacter oxydans cells subcultured in accordance with the third aspect of the present invention in 0, 50, 100, and 150 passages;
- Figure 7 is a cluster analysis of Bacillus megaterium protein of subculture 0, 50, 100, 150 passages according to the third aspect of the present invention.
- Figure 8 is a category 2 of a B. megaterium cluster analysis of subcultures 0, 50, 100, 150 passages according to a third aspect of the present invention.
- Figure 9 is a graph showing changes in phospholipid content of Bacillus megaterium at different passage times in accordance with the fourth aspect of the present invention
- Figure 10 is a principal component analysis score map (Figure 10-1) and a load map ( Figure 10-2) of Bacillus megaterium at different passage times according to the fourth aspect of the present invention
- Figure 11 is a graph showing changes in phospholipid molecular marker content of Bacillus megaterium at different passage times according to the fourth aspect of the present invention.
- Figure 12 is a graph showing changes in phospholipid content of Gluconobacter oxydans at different passage times according to the fourth aspect of the present invention.
- Figure 13 is a graph showing the principal component analysis scores (Fig. 13-1) and load maps (Fig. 13-2) of Gluconobacter oxydans at different passage times according to the fourth aspect of the present invention
- Figure 14 is a graph showing changes in the phospholipid molecular marker content of Gluconobacter oxydans at different passage times according to the fourth aspect of the present invention.
- Figure 15 is a graph showing changes in the phosphorus content of the mixed bacteria of different passage times according to the fourth aspect of the present invention.
- Figure 16 is a graph showing the principal component analysis scores (Fig. 16-1) and load diagrams (Fig. 16-2) of the mixed bacteria of different passage times according to the fourth aspect of the present invention.
- Fig. 17 is a graph showing changes in the content of phospholipid molecular markers of mixed bacteria at different passage times according to the fourth aspect of the present invention.
- Figure 18 is a Principal Component Analysis score map (Figure 18-1) and load map ( Figure 18-2) of the G. oxidans glucone environment at different passage times in accordance with the fifth aspect of the present invention
- Figure 19 is a graph showing changes in nutrient environmental markers during the subculture of Gluconobacter oxydans at different passage times in accordance with the fifth aspect of the present invention.
- Figure 20 is a principal component analysis score diagram (Fig. 20-1) and a load diagram (Fig. 20-2) of a B. megaterium nutrient environmental substance of different passage times according to the fifth aspect of the present invention
- Figure 21 is a graph showing changes in nutrient environmental markers during the subculture of Bacillus megaterium at different passage times in accordance with the fifth aspect of the present invention.
- Figure 22 is a mixture of different passage times according to the fifth aspect of the present invention.
- Fig. 23 is a difference in nutrient environment during mixed passage culture of different passage times according to the fifth aspect of the present invention a map of changes in matter;
- Figure 24 is a graph showing the principal component analysis scores of the small molecular metabolites of Gluconobacter oxydans in different passage times according to the sixth aspect of the present invention (Fig. 24-1) and load maps (Fig. 24)
- Figure 25 is a graph showing changes in the content of small molecule metabolite markers during subculture of Gluconobacter oxydans in different passage times according to the sixth aspect of the present invention.
- Figure 26 is a principal component analysis score map (Figure 26-1) and load map ( Figure 26-2) of Bacillus megaterium small molecule metabolites of different passage times in accordance with the sixth aspect of the present invention
- Figure 27 is a graph showing changes in the content of small molecule metabolite markers during the subculture of Bacillus megaterium at different passage times in accordance with the sixth aspect of the present invention.
- FIG 28 is a analysis diagram (FIG. 28-1) and the load ( Figure 28-2) depending on the generation time of the sixth aspect of the present invention, the main component mixed small molecule metabolites of bacteria;
- FIG. 29 according to the present The sixth aspect of the invention changes the content of small molecule metabolite markers during mixed passage culture of different passage times;
- Figure 30 is a diagram showing the results of fermentation of Gluconobacter oxydans and Bacillus megaterium containing the gene encoding the kaempferol dehydrogenase gene according to the seventh aspect of the present invention
- Figure 31 is a principal component analysis of four sets of sample protein (mixed solution) data according to the eighth aspect of the present invention:
- B material load diagram
- FIG 32 is a diagram showing the expression of a thiamine transporter and an important enzyme thereof as a coenzyme according to the eighth aspect of the present invention: GSH-1h/KV-lh, which is derived from the medium B lh Sample/sample from medium A lh; KV-15h/KV-lh, representing sample from medium A 15h / sample from medium A lh, GSH-15h/KV-lh, indicating from medium B 15h Sample / sample from medium A lh;
- Figure 33 is a diagram showing the expression of key enzymes in the tricarboxylic acid cycle, pentose phosphate pathway according to the eighth aspect of the present invention: GSH-1h/KV-lh, representing a sample from the medium Blh/from the medium A lh Sample; KV-15h/KV-lh, representing sample from medium A 15h / sample from medium A lh, GSH-15h/KV-lh, representing sample from medium B 15h / from medium A lh sample;
- Figure 34 is a partial least squares discriminant analysis score chart of different batches of corn syrup according to the ninth aspect of the present invention
- Figure 34-1 is a principal component analysis of different batches of corn syrup t[l]-t[2]
- Figure 34-2 is a plot of principal component analysis of different batches of corn syrup t[l]-u[l];
- Figure 35 is a partial least squares discriminant analysis load of different batches of corn syrup according to the ninth aspect of the present invention; Fig.
- 35-1 is a pp(corr) S diagram of different batches of corn syrup w*c[l Buw*c[2] scatter plot;
- Figure 35-2 is the first principal component of different batches of corn syrup;
- Figure 36 is a partial least squares discriminant analysis VIP map (V..1) of different batches of corn syrup according to the ninth aspect of the present invention. detailed description
- a method for improving the yield of 2-keto-L-gulonic acid by subculture of mixed bacteria comprises the following steps: (1) Solid culture:
- the solid medium was prepared by weighing 20 g of L-xanthine, 3 g of corn syrup, 3 g of beef bone, 3 g of yeast dipping powder, urea lg, peptone 10 g, agar 20 g, KH 2 P0 4 lg, MgSO 4 0.2 g, CaC0 3 lg water to 1L, adjusted to pH 6.8, sterilized at 121 ° C for 20min, to make a solid medium;
- the seed medium was prepared as follows: L-xanthine 20g, corn syrup 3g, beef bone 3g, yeast dip 3g, urea lg, peptone 10g, KH 2 P0 4 lg, MgSO 4 0.2 g, CaC0 3 lg Add water to 1 L and adjust the pH to 6.8, 121. C sterilized for 20 min to prepare a seed culture medium;
- the Bacillus megaterium and Gluconobacter oxydans cultured in the step (1) were separately transferred to a seed medium at 30°C. C, 250 r / min shaker shaking culture, 48h, the Bacillus megaterium seed solution and Gluconobacter oxydans seed solution;
- the Bacillus megaterium and Gluconobacter oxydans was inoculated into a new seed medium, the density of the Bacillus megaterium is 2xl0 7 cfu / ml, the density of the Gluconobacter oxydans is 2xl0 9 cfu / ml, at 30.
- C 250 r / min shaker shaking culture, 24h as the passage cycle, the volume ratio of 4% for the passage ratio into the new seed medium, passage for 50 days;
- the subcultured mixed strain obtained in the step (2) is streaked and purified, and then inoculated on a solid medium at 30 ° C for 48 hours; and then transferred to a seed medium at 30 ° C, 250 r / The shaker was shake-cultured for 48 hours to obtain the evolved Bacillus megaterium seed solution and the evolved Gluconobacter oxydans seed solution; (4) Fermentation:
- the fermentation medium was prepared by weighing 80 g of L-xanthine, 20 g of corn syrup, 12 g of urea, 12 g of urea, KH 2 P0 4 lg, MgSO 4 0.5 g, CaC0 3 lg, adding water to 1 L, and adjusting the pH to 7.0, 121. C sterilized for 20 min to prepare a fermentation medium;
- the original Bacillus megaterium and the evolved Gluconobacter oxydans were inoculated into the fermentation medium, and the density of Bacillus megaterium was 2 ⁇ 10 7 cfu/ml, and the density of the evolved Gluconobacter oxydans was 2 ⁇ 10 9 .
- HPLC High performance liquid chromatography
- Sample preparation Take 1 mL of fermentation broth at different times in a 1.5 mL centrifuge tube, centrifuge at 10000 r/min for 3 min, take the supernatant ⁇ in a 1.5 mL centrifuge tube, and add 900 ⁇ M ⁇ 2 phase (5 mM H 2 S0 4 ) A sample that is ten times dry is obtained. After oscillating and mixing, the sample was filtered through a 0.22 ⁇ m cellulose microporous membrane to obtain a sample to be tested.
- High performance liquid chromatography conditions Color column: bio-rad HPX-87H, mobile phase: 5 mM H 2 S0 4 , flow rate: 0.6 mL/min, column temperature: 65. C, the differential detector.
- ⁇ Original Gluconobacter oxydans and original Bacillus megaterium
- ⁇ Passage 50 days of Gluconobacter oxydans and original Bacillus megaterium.
- the yield of 2-keto-L-gulonic acid fermented by the 50-day subculture of Gluconobacter oxydans and the original Bacillus megaterium was 88.2%, with an increase of 10.2%.
- Example 1-2 A method for improving the yield of 2-keto-L-gulonic acid by subculture of mixed bacteria comprises the following steps:
- Gluconobacter oxydans and ⁇ stored in a 30% by volume aqueous solution of glycerol (Bacillus megaterium) in a 30% volume aqueous solution of glycerol Inoculated on solid medium, cultured at 35 ° C for 24 hours;
- the Bacillus megaterium and Gluconobacter oxydans cultured in the step (1) were separately transferred to the seed medium at 35. C, 200 r / min shaker shaking culture for 24h, obtaining Bacillus megaterium seed solution and Gluconobacter oxydans seed solution;
- the Bacillus megaterium and Gluconobacter oxydans was inoculated into a new seed medium, the density of the Bacillus megaterium is 2xl0 7 cfu / ml, the density of the Gluconobacter oxydans was 2xl0 8 cfu / ml, at 35. C, 200r / min shaker shaking culture, with 24h as the passage cycle, the volume ratio of 2% for the passage ratio into the new seed medium, passage 60 days;
- the subcultured mixed strain obtained in the step (2) was streaked and purified, and then inoculated on a solid medium, and cultured at 35 C for 24 hours; respectively, transferred to a seed medium, and shaken at 35 ° C, 200 r / min.
- the bed was cultured for 24 hours, and the evolved Bacillus megaterium seed solution and the evolved Gluconobacter oxydans seed solution were obtained;
- the original Bacillus megaterium and the evolved Gluconobacter oxydans were inoculated into the fermentation medium, and the density of Bacillus megaterium was 2 ⁇ 10 7 cfu/ml, and the density of the evolved Gluconobacter oxydans was 2 ⁇ 10 9 .
- the medium used in this example Preparation of solid medium: Weigh scale mountain Qian L- sugar 10g, corn steep liquor 10 g, beef bone 5 g, yeast extract 2 g, urea 5 g, peptone 5 g, agar 10 g, KH 2 P0 4 5 g, MgSO 4 0.5 g, CaCO 3 0.5 g, water was added to 1 L, pH was adjusted to 6.5, and sterilized at 121 ° C for 20 min to prepare a solid medium.
- the seed medium was prepared as follows: 10 g of L-xanthose, 10 g of corn syrup, 8 g of beef bone, 8 g of beef bone, 2 g of yeast powder, 5 g of urea, 2 g of peptone, KH 2 P0 4 5 g, 0.5 g of MgSO 4 , CaCO 3 0.5 g, add water to 1L, adjust the pH to 6.5, 121. C was sterilized for 20 min to prepare a seed medium.
- the fermentation medium was prepared as follows: 40 g of L-xanthine, 50 g of corn syrup, 20 g of urea, 20 g of urea, 0.5 g of KH 2 PO 4 , 1.2 g of MgS0 4 , 2 g of CaC0 3 2 g of water were added to 1 L, and the pH was adjusted to 6.5, 121. C was sterilized for 20 min to prepare a fermentation medium.
- a method for improving the yield of 2-keto-L-gulonic acid by subculture of mixed bacteria comprising the following steps:
- the Bacillus megaterium and Gluconobacter oxydans cultured in the step (1) were separately transferred to a seed medium at 30°C. C, 240 r / min shaker shaking culture for 36h, obtaining Bacillus megaterium seed solution and Gluconobacter oxydans seed solution;
- Bacillus megaterium and Gluconobacter oxydans were inoculated into a new seed medium such that the density of Bacillus megaterium was 2 x 10 8 cfu/ml, and the density of Gluconobacter oxydans was 2 x 10 n cfu/ml at 30.
- the subcultured mixed strain obtained in the step (2) was streaked and purified, and then inoculated separately on a solid medium, 30.
- C was cultured for 36 hours; then transferred to seed culture medium, and cultured at 30 ° C, 240 r / min shaker for 36 h, to obtain an evolved Bacillus megaterium seed solution and an evolved Gluconobacter oxydans seed solution;
- the original Bacillus megaterium and the evolved Gluconobacter oxydans were inoculated into the fermentation medium, and the density of Bacillus megaterium was 2 ⁇ 10 8 cfu/ml, and the density of the evolved Gluconobacter oxydans was 2 ⁇ 10 U. Cfu/ml, at 30. C, 240 r / min shaker shaking culture for 96h, to obtain 2-keto-L-gulonic acid.
- the solid medium was prepared by weighing 30 g of L-xanthine, 2 g of corn syrup, 10 g of beef bone, 5 g of yeast extract, 0.5 g of urea, 12 g of peptone, 30 g of agar, and KH 2 PO 4 0.5. g, MgSO 4 0.7 g, CaCO 3 3 g, water was added to 1 L, and the pH was adjusted to 6.8, 121. C was sterilized for 20 min to prepare a solid medium.
- the seed medium was prepared as follows: Weighed 30 g of L-wheat sugar, 2 g of corn syrup, 10 g of beef bone, 8 g of yeast extract, urea 0.5 g, peptone 8 g, KH 2 PO 4 0.5 g, MgSO 4 0.7 g, CaC0 3 3g, add water to 1L, adjust the pH to 6.8, 121. C was sterilized for 20 min to prepare a seed medium.
- the fermentation medium was prepared by weighing 80 g of L-xanthine, 10 g of corn syrup, 25 g of urea, 25 g of KH 2 P0 4 lg, 0.2 g of MgSO 4 , and 5 g of CaC0 3 to 1 L, and adjusted to pH 6.8, 121. C was sterilized for 20 min to prepare a fermentation medium.
- a method for improving the yield of 2-keto-L-gulonic acid by subculture of mixed bacteria comprises the following steps: (1) Solid culture:
- the Bacillus megaterium and Gluconobacter oxydans cultured in step (1) were separately transferred to seed medium at 28. C, 280 r / min shaker shaking culture for 48h, obtaining Bacillus megaterium seed solution and Gluconobacter oxydans seed solution;
- the Bacillus megaterium and Gluconobacter oxydans was inoculated into a new seed medium, so that the density of Bacillus megaterium 2xlO ie cfu / ml, the density of the Gluconobacter oxydans is 2xlO n cfu / ml, at 28. C, 280 r / min shaker shaking culture, 48h as the passage cycle, the volume ratio of 10% for the passage ratio into the new seed medium, passaging 80 days;
- the subcultured mixed strain obtained in the step (2) was streaked and purified, and then inoculated on a solid medium, respectively.
- C was cultured for 48 hours; then transferred to seed culture medium, and cultured at 28 °C, 280 r/min shaker for 48 hours, to obtain an evolved Bacillus megaterium seed solution and an evolved Gluconobacter oxydans seed solution;
- the original Bacillus megaterium and the evolved Gluconobacter oxydans were inoculated into the fermentation medium, and the density of Bacillus megaterium was , the density of the evolved Gluconobacter oxydans is 2xlO u cfu / ml, at 28. C, 280 r / min shaker shaking culture for 72h, to obtain 2-keto-L-gulonic acid.
- the solid medium was prepared by weighing: 50 g of L-wheat sugar, 5 g of corn syrup, 2 g of beef bone, 10 g of yeast extract, 3 g of urea, 2 g of peptone, 50 g of agar, KH 2 P0 4 3g, MgSO 4 0.1 g, CaC0 3 5 g, water was added to 1 L, and the pH was adjusted to 7.0, 121. C was sterilized for 20 min to prepare a solid medium.
- the seed medium was prepared as follows: Proportioned L-mountain 50g, corn syrup 8g, beef bone 2g, yeast dipping powder 10g, urea 3g, peptone 12g, KH 2 P0 4 3g, MgSO 4 0.1g, CaCO 3 0.5 -5g, add water to 1L, adjust the pH to 7.0,121. C was sterilized for 20 min to prepare a seed medium.
- the fermentation medium was prepared as follows: Weigh 120 g of L-wheat sugar, 30 g of corn syrup, 10 g of urea, 10 g of urea, KH 2 P0 4 3 g, 0.5 g of MgSO 4 , 0.5 g of CaCO 3 and 1 L of water, adjusted to pH 7.5, 121 . C was sterilized for 20 min to prepare a fermentation medium.
- Example 2-1 Weigh 120 g of L-wheat sugar, 30 g of corn syrup, 10 g of urea, 10 g of urea, KH 2 P0 4 3 g, 0.5 g of MgSO 4 , 0.5 g of CaCO 3 and 1 L of water, adjusted to pH 7.5, 121 . C was sterilized for 20 min to prepare a fermentation medium.
- a method for enhancing 2-bacterium interaction to increase 2-keto-L-gulonic acid production comprising the following steps:
- the solid medium was prepared by weighing 20 g of L-xanthine, 3 g of corn syrup, 3 g of beef bone, 3 g of yeast dipping powder, urea lg, peptone 10 g, agar 20 g, KH 2 P0 4 lg, MgSO 4 0.2 g, CaC0 3 lg water to 1L, adjusted to pH 6.8, sterilized at 121 ° C for 20min, to make a solid medium;
- the seed medium was prepared as follows: L-xanthine 20g, corn syrup 3g, beef bone 3g, yeast dip 3g, urea lg, peptone 10g, KH 2 P0 4 lg, MgSO 4 0.2 g, CaC0 3 lg Add water to 1 L and adjust the pH to 6.8, 121. C sterilization for 20min, made into seeds Medium
- the Bacillus megaterium and Gluconobacter oxydans cultured in the step (1) were separately transferred to a seed medium at 30°C. C, 250 r / min shaker shaking culture, 48h, the Bacillus megaterium seed solution and Gluconobacter oxydans seed solution;
- the Bacillus megaterium and Gluconobacter oxydans was inoculated into a new seed medium, the density of the Bacillus megaterium is 2xl0 7 cfu / ml, the density of the Gluconobacter oxydans is 2xl0 9 cfu / ml, at 30.
- C 250 r / min shaker shaking culture, 24h as the passage cycle, the volume ratio of 4% for the passage ratio into the new seed medium, passaging for 100 days;
- the subcultured mixed strain obtained in the step (2) is streaked and purified, and then inoculated on a solid medium at 30 ° C for 48 hours; and then transferred to a seed medium at 30 ° C, 250 r / The shaker was shake-cultured for 48 hours to obtain the evolved Bacillus megaterium seed solution and the evolved Gluconobacter oxydans seed solution;
- the fermentation medium was prepared by weighing 80 g of L-xanthine, 20 g of corn syrup, 12 g of urea, 12 g of urea, KH 2 P0 4 lg, MgSO 4 0.5 g, CaC0 3 lg, adding water to 1 L, and adjusting the pH to 7.0, 121. C sterilized for 20 min to prepare a fermentation medium;
- a method for enhancing 2-bacterium interaction to increase 2-keto-L-gulonic acid production comprising the following steps:
- Steps (1), (2), and (3) are the same as the embodiment 2-1
- HPLC High performance liquid chromatography
- Sample preparation Take 1 mL of fermentation broth at different times in a 1.5 mL centrifuge tube, centrifuge at 10000 r/min for 3 min, take the supernatant ⁇ in a 1.5 mL centrifuge tube, and add 900 ⁇ M ⁇ 2 phase (5 mM H 2 S0 4 ) A sample that is ten times dry is obtained. After oscillating and mixing, the sample was filtered through a 0.22 ⁇ m cellulose microporous membrane to obtain a sample to be tested.
- High performance liquid chromatography conditions Color column: bio-rad HPX-87H, mobile phase: 5 mM H 2 S0 4 , flow rate: 0.6 mL/min, column temperature: 65. C, the differential detector.
- ⁇ Original Gluconobacter oxydans and B. megaterium; ⁇ : Passage for 100 days of Gluconobacter oxydans and passage of 100-day Bacillus megaterium; ⁇ : Passage for 100 days of Gluconobacter oxydans and Bacillus megaterium; The yield of 2-keto-L-gulonic acid of the original Gluconobacter oxydans and the original Bacillus megaterium using the fermentation conditions of the step (4) of Example 2-1 was 78%; using Example 2-1 The method of subculture for 100 days of evolution of Gluconobacter oxydans and subculture of 100 days of evolution of Bacillus megaterium mixed fermentation of 2-keto-L-gulonic acid yielded 91%-92%, it The yield of 2-keto-L-gulonic acid fermented by the mixed bacteria of the original Gluconobacter oxydans and the original Bacillus megaterium was increased by 13% -14%; the G.
- Example 2-3 oxydans subcultured for 100 days was matched with the original Bacillus megaterium.
- Example 2-3 The mixed fermentation (Example 2-2) fermentation cycle and 2-keto-L-gulonic acid conversion were similar to the G. oxydans subcultured for 100 days and the mixed Bacillus megaterium fermentation for 100 days.
- Example 2-3
- a method for enhancing 2-bacterium interaction to increase 2-keto-L-gulonic acid production comprising the following steps:
- Gluconobacter oxydans and ⁇ stored in a 30% by volume aqueous solution of glycerol (Bacillus megaterium) in a 30% volume aqueous solution of glycerol Inoculated on solid medium, cultured at 35 ° C for 24 hours;
- the Bacillus megaterium and Gluconobacter oxydans cultured in the step (1) were separately transferred to the seed medium at 35. C, 200 r / min shaker shaking culture for 24h, obtaining Bacillus megaterium seed solution and Gluconobacter oxydans seed solution;
- the Bacillus megaterium and Gluconobacter oxydans was inoculated into a new seed medium, the density of the Bacillus megaterium is 2xl0 7 cfu / ml, the density of the Gluconobacter oxydans was 2xl0 8 cfu / ml, at 35.
- C 200r/min shaker shaking culture, with 24h as the passage cycle, with a volume ratio of 2% as the passage ratio into the new seed medium, passaging for 150 days;
- the subcultured mixed strain obtained in the step (2) was streaked and purified, and then inoculated on a solid medium, and cultured at 35 C for 24 hours; respectively, transferred to a seed medium, and shaken at 35 ° C, 200 r / min.
- the bed was cultured for 24 hours, and the evolved Bacillus megaterium seed solution and the evolved Gluconobacter oxydans seed solution were obtained;
- the evolved Bacillus megaterium and the evolved Gluconobacter oxydans were inoculated into a fermentation medium, and the density of the evolved Bacillus megaterium was 2 ⁇ 10 7 cfu/ml, and the density of the evolved Gluconobacter oxydans was increased. It is 2xl0 8 cfu/ml, at 35. C, 200r/min shake flask was cultured for 96h to obtain 2-keto-L-gulonic acid.
- the seed medium was prepared as follows: 10 g of L-xanthose, 10 g of corn syrup, 8 g of beef bone, 8 g of beef bone, 2 g of yeast powder, 5 g of urea, 2 g of peptone, KH 2 P0 4 5 g, 0.5 g of MgSO 4 , CaCO 3 0.5 g, add water to 1L, adjust the pH to 6.5, 121. C was sterilized for 20 min to prepare a seed medium.
- the fermentation medium was prepared as follows: 40 g of L-xanthine, 50 g of corn syrup, 20 g of urea, 20 g of urea, 0.5 g of KH 2 PO 4 , 1.2 g of MgS0 4 , 2 g of CaC0 3 2 g of water were added to 1 L, and the pH was adjusted to 6.5, 121. C was sterilized for 20 min to prepare a fermentation medium.
- a method for enhancing 2-bacterium interaction to increase 2-keto-L-gulonic acid production comprising the following steps:
- Steps (1), (2), and (3) are the same as Examples 2-3
- the original Bacillus megaterium and the evolved Gluconobacter oxydans were inoculated into the fermentation medium, and the density of Bacillus megaterium was 2 ⁇ 10 7 cfu/ml, and the density of the evolved Gluconobacter oxydans was 2 ⁇ 10 9 .
- Each medium was the same as in Example 2-2.
- ⁇ Original Gluconobacter oxydans and original Bacillus megaterium
- mouth Passage 150 days of Gluconobacter oxydans and passaging 150 days of Bacillus megaterium
- ⁇ Passage 150 days of Gluconobacter oxydans and original Bacillus megaterium
- o raw oxidized glucose rod The bacteria were mixed with a 150-day Bacillus megaterium.
- the yield of 2-keto-L-gulonic acid of the original Gluconobacter oxydans and the original Bacillus megaterium using the fermentation conditions of the step (4) of Example 2-3 was 78%; using Example 2-3 The method of subculture of 150 days of evolution of Gluconobacter oxydans and subculture of 150 days of evolution of the Bacillus megaterium mixed fermentation of 2-keto-L-gulonic acid yield reached 95% at the end of the fermentation, than the original The 2-keto-L-gulonic acid yield mixed bacteria fermented by Gluconobacter oxydans and B. megaterium increased by 17%, and the fermentation cycle was shortened by 9% compared with the original mixed bacteria. Subculture for 150 days.
- the 2-keto-L-gulonic acid conversion rate of the mixed fermentation system of the Gluconobacter oxydans and the original Bacillus megaterium was 16% higher than that of the original mixed bacteria, and the fermentation cycle and subculture 150 The days of mixed bacteria are similar.
- a method for enhancing 2-bacterium interaction to increase 2-keto-L-gulonic acid production comprising the following steps:
- the Bacillus megaterium and Gluconobacter oxydans cultured in the step (1) were separately transferred to a seed medium at 30°C. C, 240 r / min shaker shaking culture for 36h, obtaining Bacillus megaterium seed solution and Gluconobacter oxydans seed solution;
- Bacillus megaterium and Gluconobacter oxydans were inoculated into a new seed medium such that the density of Bacillus megaterium was 2 x 10 8 cfu/ml, and the density of Gluconobacter oxydans was 2 x 10 n cfu/ml at 30.
- the subcultured mixed strain obtained in the step (2) was streaked and purified, and then inoculated separately on a solid medium, 30.
- C was cultured for 36 hours; then transferred to seed culture medium, and cultured at 30 ° C, 240 r / min shaker for 36 h, to obtain an evolved Bacillus megaterium seed solution and an evolved Gluconobacter oxydans seed solution;
- the evolved Bacillus megaterium and the evolved Gluconobacter oxydans were inoculated into a fermentation medium, and the density of the evolved Bacillus megaterium was 2 ⁇ 10 8 cfu/ml, and the density of the evolved Gluconobacter oxydans was increased.
- ZxloUcfu/ml at 30. C, 240 r / min shaker shaking culture for 96h, to obtain 2-keto-L-gulonic acid.
- the solid medium was prepared by weighing 30 g of L-xanthine, 2 g of corn syrup, 10 g of beef bone, 5 g of yeast extract, 0.5 g of urea, 12 g of peptone, 30 g of agar, and KH 2 PO 4 0.5. g, MgSO 4 0.7 g, CaCO 3 3 g, water was added to 1 L, and the pH was adjusted to 6.8, 121. C was sterilized for 20 min to prepare a solid medium.
- the seed medium was prepared as follows: Weighed 30 g of L-wheat sugar, 2 g of corn syrup, 10 g of beef bone, 8 g of yeast extract, urea 0.5 g, peptone 8 g, KH 2 PO 4 0.5 g, MgSO 4 0.7 g, CaC0 3 3g, add water to 1L, adjust the pH to 6.8, 121. C was sterilized for 20 min to prepare a seed medium.
- the fermentation medium was prepared by weighing 80 g of L-xanthine, 10 g of corn syrup, 25 g of urea, 25 g of KH 2 P0 4 lg, 0.2 g of MgSO 4 , and 5 g of CaC0 3 to 1 L, and adjusted to pH 6.8, 121. C was sterilized for 20 min to prepare a fermentation medium.
- a method for enhancing the interaction of two bacteria to increase the yield of 2-keto-L-gulonic acid comprising the following steps: (1) Solid culture:
- the Bacillus megaterium and Gluconobacter oxydans cultured in step (1) were separately transferred to seed medium at 28. C, 280 r / min shaker shaking culture for 48h, obtaining Bacillus megaterium seed solution and Gluconobacter oxydans seed solution;
- the Bacillus megaterium and Gluconobacter oxydans was inoculated into a new seed medium, so that the density of Bacillus megaterium 2xlO ie cfu / ml, the density of the Gluconobacter oxydans is 2xlO n cfu / ml, at 28. C, 280 r / min shaker shaking culture, 48h as the passage cycle, the volume ratio of 10% for the passage ratio into the new seed medium, passage for 180 days;
- the subcultured mixed strain obtained in the step (2) was streaked and purified, and then inoculated on a solid medium, respectively.
- C was cultured for 48 hours; then transferred to seed culture medium, and cultured at 28 °C, 280 r/min shaker for 48 hours, to obtain an evolved Bacillus megaterium seed solution and an evolved Gluconobacter oxydans seed solution;
- the evolved Bacillus megaterium and the evolved Gluconobacter oxydans are inoculated into a fermentation medium to make the density of the evolved Bacillus megaterium
- the density of the evolved Gluconobacter oxydans was 2xl u u cfu / ml, at 28. C, 280 r / min shaker shaking culture for 72hh, to obtain 2-keto-L-gulonic acid.
- the solid medium was prepared by weighing: 50 g of L-wheat sugar, 5 g of corn syrup, 2 g of beef bone, 10 g of yeast extract, 3 g of urea, 2 g of peptone, 50 g of agar, KH 2 P0 4 3g, MgSO 4 0.1 g, CaC0 3 5 g, water was added to 1 L, and the pH was adjusted to 7.0, 121. C was sterilized for 20 min to prepare a solid medium.
- the seed medium was prepared as follows: Proportioned L-mountain 50g, corn syrup 8g, beef bone 2g, yeast dipping powder 10g, urea 3g, peptone 12g, KH 2 P0 4 3g, MgSO 4 0.1g, CaCO 3 0.5 -5g, add water to 1L, adjust the pH to 7.0,121. C was sterilized for 20 min to prepare a seed medium.
- the fermentation medium was prepared as follows: Weigh 120 g of L-wheat sugar, 30 g of corn syrup, 10 g of urea, 10 g of urea, KH 2 P0 4 3 g, 0.5 g of MgSO 4 , 0.5 g of CaCO 3 and 1 L of water, adjusted to pH 7.5, 121 . C was sterilized for 20 min to prepare a fermentation medium.
- Example 3-1 Weigh 120 g of L-wheat sugar, 30 g of corn syrup, 10 g of urea, 10 g of urea, KH 2 P0 4 3 g, 0.5 g of MgSO 4 , 0.5 g of CaCO 3 and 1 L of water, adjusted to pH 7.5, 121 . C was sterilized for 20 min to prepare a fermentation medium.
- Example 3-1 Example 3-1
- a method for detecting vitamin C industrial mixed bacteria to pass on different algebraic protein changes comprising the following steps:
- the Bacillus megaterium and Gluconobacter oxydans cultured in the step (1) 1 were separately transferred to a seed medium at 28. C, 200r / min shaker shaking culture for 24h, obtaining Bacillus megaterium seed solution and Gluconobacter oxydans seed solution;
- Bacillus megaterium and Gluconobacter oxydans were inoculated into a new seed medium such that the density of Bacillus megaterium was 2 x 10 7 CFU/mL, and the density of Gluconobacter oxydans was 2 x 10 8 CFU/mL, at 28. C, 200 r/min shaking shake culture, with 24h as the passage week Period, the volume ratio of 1% is used as the passage ratio to access the new seed culture medium, passaging for 150 days, and selecting 4 sampling times to take 4 samples, respectively, are 0 days, 50 days, 100 days, 150 days;
- the four mixed cells obtained in the step (1) 2 were streaked and purified, and then inoculated on a solid medium, respectively.
- C was cultured for 24 h; then transferred to seed medium separately at 28.
- C 200 rpm shaker shaking culture for 24 h, the evolved Bacillus megaterium seed solution and the evolved Gluconobacter oxydans seed solution; preserved in a 15% volume aqueous solution of glycerol;
- the evolved Bacillus megaterium and the evolved Gluconobacter oxydans obtained in the step (1) 3 were inoculated into the seed medium, respectively, so that the density of the evolved Bacillus megaterium was 2 ⁇ 10 7 CFU/mL, and the evolution was oxidized.
- the density of Gluconobacter is
- the Bacillus megaterium culture and the oxidized Glucose oxidase culture obtained in step (1) 4, respectively, are at 4. Centrifuge at 4000 rpm, collect the lower layer of cells, wash with phosphate buffer of pH 7.2, quench with liquid nitrogen, terminate the metabolic reaction; crush the cells with liquid nitrogen grinding;
- the broken cells were placed in a centrifuge tube, each of which was placed in a centrifuge tube, 0.5 mL of cell lysate was added to each tube, mixed, and sonicated on ice for 20 s; 5 L of DNase I / RNaseA enzyme at a mass ratio of 2:1 was added. Mix the solution and mix well, 4. C. The reaction was allowed to stand for 10 min; 5 L of 80 mM phenylmethylsulfonyl fluoride isopropanol solution was added, 4. C is allowed to stand lh; centrifuged at 15000 rpm for 25 min; the supernatant is taken to obtain a protein solution;
- the cell lysate is: 8 mol-L 1 urea, a concentration of 4% 3-[(3) -cholestylpropyl)-diethylamine]-propanesulfonic acid, 40 mM Tris, the balance being water;
- the Bradford kit was used to convert bovine serum albumin from a low concentration to a high concentration into Coomassie Brilliant Blue G-250 solution.
- the absorbance of each protein solution obtained in step (2) 2 at 595 nm was determined to establish a standard curve; each protein was determined.
- Each protein solution obtained in the step (2) 2 containing 50 proteins was added, and 4 volumes of -20 were added per portion.
- the candidate differential protein content obtained in step (3) is plotted according to time series, and the regularity of these protein changes is observed and analyzed, and then the mixed culture evolution culture is found to improve the production of 2-keto-L-gulonic acid by Gluconobacter oxydans. The role.
- Gluconobacter oxidans produced a variety of evolutionary directions, showing that intracellular proteins exhibit different expression patterns in different algebras, as shown in Figure 5.
- category 1, category 3 and category 5 showed little change in the expression of each generation of proteins; category 2 and category 4 showed different degrees of evolutionary protein sheets.
- Raise including the hawthorn/bean ketone dehydrogenase responsible for the conversion of hawthorn sugar to 2-keto-L-gulonic acid.
- the expression of this enzyme in the generation is shown in Fig. 6. It was slightly down-regulated in the 50th generation, and gradually increased in the 100th and 150th generations.
- the reason for this phenomenon may be that during the 50th generation, the violent interaction between the mixed bacteria occurs, and the adaptive selection is carried out. With the synergistic effect, the Gluconobacter oxidans is more and more adapted to the mixed environment and has a stronger Production capacity.
- Immune inhibitor A is a protein that degrades antibacterial peptides in Islam, and plays an important role in the resistance of Bacillus to the external immune system. In addition, it is an important component of the outer wall of Bacillus spores. The expression level increased with the subculture algebra and showed an up-regulation, indicating that the resistance of Bacillus megaterium spores was improved. At the same time, the ability to transport oligopeptides has also increased, which is conducive to their own growth needs.
- a method for detecting vitamin C industrial mixed bacteria to pass on different algebraic protein changes comprising the following steps:
- Gluconobacter oxydans stored in a volumetric 20% glycerol aqueous solution and Bacillus megaterium deposited in a 20% by volume aqueous solution of glycerol in a volume of 20% glycerol solution were inoculated separately. On a solid medium, cultured at 30 ° C for 36 hours;
- the Bacillus megaterium and Gluconobacter oxydans cultured in the step (1) 1 were separately transferred to a seed medium at 30°C. C, 250 r / min shaker shaking culture for 36h, obtaining Bacillus megaterium seed solution and Gluconobacter oxydans seed solution;
- the three mixed cells obtained in the step (1) 2 were streaked and purified, and then inoculated separately on a solid medium, 30.
- C shaking culture at 250 rpm for 36 h, obtaining an evolved Bacillus megaterus seed solution and an evolved Gluconobacter oxydans seed solution; stored in a 20% by volume aqueous solution of glycerin;
- the evolved Bacillus megaterium and the evolved Gluconobacter oxydans obtained in the step (1) 3 were inoculated separately into the seed medium, and the evolved Bacillus megaterium had a density of 2 ⁇ 10 8 CFU/mL, and the evolved oxidation.
- the density of Gluconobacter is
- the Bacillus megaterium culture and the oxidized Glucose oxidase culture obtained in step (1) 4, respectively, are at 4. After centrifugation at 5000 rpm, the lower layer of cells was collected, washed with a phosphate buffer solution of pH 7.3, quenched with liquid nitrogen, and the metabolic reaction was terminated; the cells were disrupted by liquid nitrogen milling;
- the crushed cells were placed in a centrifuge tube, 90 mL of each was placed in a centrifuge tube, 0.8 mL of cell lysate was added to each tube, mixed, and sonicated on ice for 40 s; DNase I / RNaseA enzyme with a mass ratio of 3:1 was added. Mix the solution and mix well, 4. C was allowed to stand for 20 min; 10 L OO mM of a phenylmethylsulfonyl isopropanol solution was added, 4. C is allowed to stand for 2h; Centrifuge at 15000 rpm for 30 min; take the supernatant to obtain a protein solution;
- the cell lysate is: 8 mol-L 1 urea, 4% by mass of 3-[(3-cholamidopropyl)-diethylamine]-propanesulfonic acid, 40 mM Tris, the balance being water ;
- the Bradford kit was used to convert bovine serum albumin from a low concentration to a high concentration into Coomassie Brilliant Blue G-250 solution.
- the absorbance of each protein solution obtained in step (2) 2 at 595 nm was determined to establish a standard curve; each protein was determined.
- the candidate differential protein content obtained in step (3) is plotted according to time series, and the regularity of these protein changes is observed and analyzed, and then the mixed culture evolution culture is found to improve the production of 2-keto-L-gulonic acid by Gluconobacter oxydans. The role.
- a method for detecting vitamin C industrial mixed bacteria to pass on different algebraic protein changes comprising the following steps:
- the Bacillus megaterium and Gluconobacter oxydans cultured in the step (1) 1 were separately transferred to a seed medium at 35°C. C, 280 r / min shaker shaking culture for 48h, obtaining Bacillus megaterium seed solution and Gluconobacter oxydans seed solution;
- Bacillus megaterium and Gluconobacter oxydans were inoculated into a new seed medium such that the density of Bacillus megaterium was 2 x 10 1 G CFU/mL, and the density of Gluconobacter oxydans was 2 x 10 n CFU/mL at 35.
- C, 280 r/min shaker shaking culture with 48h as passage Cycle, with a volume ratio of 10% as the passage ratio into the new seed medium, pass through 150 days, select 4 sampling times to take 4 samples, respectively 0 days, 50 days, 100 days, 150 days;
- the four mixed cells obtained in the step (1) 2 were streaked and purified, and then inoculated separately on a solid medium, 35.
- C was cultured for 48 h; and then transferred to seed medium separately at 35.
- C shaking culture at 280 rpm for 48 h, obtaining an evolved Bacillus megaterus seed solution and an evolved Gluconobacter oxydans seed solution; deposited in a 30% volume aqueous solution of glycerin;
- the evolved Bacillus megaterium and the evolved Gluconobacter oxydans obtained in the step (1) 3 were inoculated separately into the seed medium, so that the density of the evolved Bacillus megaterium was 2xlO ie CFU/mL, and the evolution was oxidized.
- the density of Gluconobacter is
- the Bacillus megaterium culture and the oxidized Glucose oxidase culture obtained in the step (1) 4, respectively, are at 4.
- C centrifuge at 6000 rpm, collect the lower layer of cells, and wash with phosphate buffer of pH 7.4, quench with liquid nitrogen to terminate the metabolic reaction; crush the cells with liquid nitrogen grinding;
- each 100 mg of each is placed in a centrifuge tube, add 1 mL of cell lysate to each tube, mix, and acoustically disrupte on ice for 50 s; add 15 L of DNase l / RNaseA enzyme with a mass ratio of 4:1. Solution, mix, 4. C was allowed to stand for 30 min; 15 L of 120 mM phenylmethylsulfonyl isopropanol solution was added, 4. C is allowed to stand for 3 hours;
- the cell lysate is: 8 mol-L 1 urea, a concentration of 4% 3-[(3) -cholestylpropyl)-diethylamine]-propanesulfonic acid, 40 mM Tris, the balance being water;
- the Bradford kit was used to convert bovine serum albumin from a low concentration to a high concentration into Coomassie Brilliant Blue G-250 solution.
- the absorbance of each protein solution obtained in step (2) 2 at 595 nm was determined to establish a standard curve; each protein was determined.
- Each of the protein solutions obtained in the step (2) 2 containing 100 proteins was added to each of 6 volumes of -40.
- C acetone, at -40. Place C under ⁇ for 20h; centrifuge, discard the supernatant, and use -40 for precipitation. Washing with a volumetric concentration of C of 85% aqueous acetone; drying to obtain a dry protein powder;
- the candidate differential protein content obtained in step (3) is plotted according to time series, and the regularity of these protein changes is observed and analyzed, and then the mixed culture evolution culture is found to improve the production of 2-keto-L-gulonic acid by Gluconobacter oxydans. The role.
- Example 3-2 and Example 3-3 are similar to those of Example 3-1.
- the composition of the solid medium and the seed medium used in the present invention is selected from the medium disclosed in Chinese Patent Application No. 201110314740.9, for example:
- Example 4-1
- a method for analyzing changes in phospholipid groups during the passage of vitamin C production strains the characteristics of which include the following steps:
- Gluconobacter oxydans and ⁇ stored in a 20% volume aqueous solution of glycerol were stored at a volume concentration of 20%.
- Bacillus megaterium in an aqueous solution was inoculated on a solid medium, and cultured at 30 ° C for 36 hours;
- the Bacillus megaterium and Gluconobacter oxydans cultured in the step (1) were separately transferred to a seed culture medium, and shake cultured at 30 ° C, shaking at 240 rpm for 36 hours to obtain a Bacillus megaterus seed solution and a Gluconobacter oxydans seed solution. ;
- the four subcultured mixed strains obtained in the step (2) were streaked and purified, and then inoculated on a solid medium, and cultured at 30 ° C for 36 hours; and then transferred to a seed medium at 30 ° C, 240 rpm. Shake the shaker for 36h to obtain the evolved Bacillus megaterium seed solution and the evolved Gluconobacter oxydans seed solution;
- the evolved Bacillus megaterium, the evolved Gluconobacter oxydans, and the mixed evolved Bacillus megaterium and the evolved Gluconobacter oxydans were inoculated separately into the fermentation medium, and the density of the evolved Bacillus megaterium was 2xl0 8 cfu/mL, the density of the evolved Gluconobacter oxydans is Incubate at 30 ° C, shaking at 240 rpm for 13 h;
- the three cells obtained in step 1 were separately ground in a mortar using liquid nitrogen to prepare a dry powder.
- Each of the 250 mg dry cell powder was weighed and placed in three centrifuge tubes A, and 0.6 mL of ultrapure water was added separately, and thoroughly mixed. ;
- step 7 The organic solvent in the mixture obtained in step 6 is distilled under reduced pressure at 30 ° C to obtain three total phospholipid extraction mixtures;
- phospholipid standards were added to the three samples.
- the phospholipid standards were bis-dodecanoylphosphatidylglycerol, bis-dodecanoylphosphatidylethanolamine, dodecanoyl hemolytic phosphatidylethanolamine and double twelve. Alkanoyl phosphatidic acid, the final concentration of these four phospholipid standards is 1.0 g / mL;
- the extract is a chloroform/methanol solution containing dibutylhydroxytoluene, the volume ratio of the chloroform/methanol is 1.5:1, and the mass fraction of the dibutylhydroxytoluene is 0.007%;
- the storage solution is a chloroform/methanol solution containing dibutylhydroxytoluene, the volume ratio of the chloroform/methanol is 2:1, and the mass fraction of the dibutylhydroxytoluene is 0.007%;
- the LC-MS detection conditions are:
- Injection volume 10 ⁇ ;
- Mobile phase A (%): chloroform (89.5), methanol (10), ammonium hydroxide (0.5); mobile phase B (%): chloroform (55), methanol (39), ammonium hydroxide (0.5), water ( 5.5);
- Ionization mode ESI (negative ion mode);
- Ion source temperature 100 ° C;
- Desolvent gas flow 400 L/Hr;
- Inlet/outlet energy 50;
- HM1/LM1/HM2/LM2 15.0; Ion Energy 1: 1.0;
- the molecular content data of the phospholipid group in the process of passage of the vitamin C production strain obtained in the step (6) were subjected to multivariate statistical analysis to obtain differential phospholipid molecular markers for distinguishing the vitamin C producing strains in different passage times; the multivariate statistical analysis method was Pareto pretreatment. After the principal component analysis; see Figure 10, Figure 13 and Figure 16;
- the content of the differential phospholipid molecular markers obtained in the step (7) was plotted according to different passage times in Fig. 11, Fig. 14 and Fig. 17, and the regularity of the changes of these phospholipid molecules was observed and analyzed, and it was found that the mixed bacteria were in the process of subculture.
- Table 4-1 Molecular identification table of Bacillus megaterium phospholipids
- PA32:1, PA32:0, PA33:1, PA33:0 As shown in Table 4-1, the vitamin C producing strain was extracted and detected by the method of the present invention.
- PA28 PA28:0 as shown in Table 4-2, extracted by the method of the present invention A total of 22 species of Gluconobacter oxydans phospholipids were detected in the vitamin C production strain, including 21 phosphatidylglycerol molecules and 1 phosphatidic acid molecule.
- PA34:1 PA35:3
- FIG. 11 shows the change in the content of outliers (molecular markers) in the load map of the main component analysis.
- PE34:2, PE34:1 and LPE16:0 had the highest content in 50 days of cells; a series of PG molecules had the lowest content in 50 days, then gradually increased; a series of PA molecules decreased significantly in 50 days, and surged again in 100 days. .
- the above changes indicate that the phospholipid metabolism process undergoes significant changes as the time between the two passages increases.
- FIG. 13 Principal component analysis was performed as a matrix of all phospholipid molecules in the 0, 50, 100, and 150 days of Gluconobacter oxydans phospholipid samples (Figure 13).
- the score plot shows a clear distinction between the 0 and 50 day cell phospholipid components, while 100 There was little difference between cells in 150 days and cells in 50 days; the load map showed that the content of PA molecules increased after 50 days of passage.
- Figure 14 is a graph showing the percentage change of molecular markers for different passage times, in which the content of PA28:0 increased with the passage time.
- the total cell phospholipid content of the mixed cells at 0, 50, 100, and 150 days was 8.39, 6.33, 6.62, and 7.91 nmol/mg dry cell weight, respectively, indicating that the total cell phospholipid content was significant at 50 days of passage. Decline, and then increase the trend.
- Principal component analysis was performed using a matrix of all phospholipid molecules in 0, 50, 100, and 150 days of mixed phospholipid samples (Figure 16). The scores show significant differences in cell phospholipids at 0, 50, 100, and 150 days.
- FIG. 17 is a phospholipid molecular marker that distinguishes mixed passages of different passage numbers.
- a series of PG and LPE molecules decreased with the passage, while PE and PA molecules increased. This indicates that as the passage time of the two bacteria increases, the interaction time prolongs and the phospholipid metabolism changes.
- the decrease of LPE and the increase of PA suggest different roles of different phospholipid metabolism-related enzymes in the common passage and cell membrane signal transduction of the two bacteria.
- a method for analyzing changes in phospholipid groups during the passage of vitamin C production strains the characteristics of which include the following steps:
- Solid culture Gluconobacter oxydans stored in a 15% volume aqueous glycerol solution and Bacillus megaterium stored in a 15% glycerol aqueous solution were inoculated on a solid medium. , 28 ° C, cultured for 48 hours;
- the Bacillus megaterium and Gluconobacter oxydans cultured in the step (1) were separately transferred to a seed culture medium, and cultured at 28 ° C, shaking at 200 rpm for 48 hours to obtain a Bacillus megaterus seed solution and a Gluconobacter oxydans seed solution. ;
- the culture was shaken at 200 rpm, and the passage time was 24 h. The volume ratio was 1% for the passage ratio.
- the new seed culture medium was used for 130 days, on the 0th, 20th, 40th, and 80th. Take 5 samples on the day of the day and the 130th day;
- the five subcultured mixed strains obtained in the step (2) were streaked and purified, and then inoculated on a solid medium, and cultured at 28 ° C for 24 hours; respectively, and then transferred to a seed medium at 28 ° C, 200 rpm.
- the shaker was shake-cultured for 48 hours to obtain an evolved Bacillus megaterus seed solution and an evolved Gluconobacter oxydans seed solution;
- the evolved Bacillus megaterium, the evolved Gluconobacter oxydans, and the mixed evolved Bacillus megaterium and the evolved Gluconobacter oxydans were respectively inoculated into a fermentation medium to make the evolved Bacillus megaterium
- the density is 2 ⁇ 10 7 cfu/mL
- the density of the evolved Gluconobacter oxydans is 2 ⁇ 10 8 cfu/mL, and cultured at 28° C., shaking at 200 rpm for 15 h;
- step 2 The cells obtained in step 1 were ground in a mortar using liquid nitrogen to prepare a dry powder, and 200 mg of dry powder was weighed, placed in a centrifuge tube A, and 0.5 mL of ultrapure water was added thereto, and thoroughly mixed;
- the total phospholipid extraction mixture is dissolved in 0.2 mL of the stock solution to prepare a sample, which is stored at -40 ° C or below.
- a phospholipid standard was added to the sample, and the phospholipid standard was m-icosyl phosphatidylglycerol and diicosyl phosphatidylethanolamine.
- the final concentration of the two phospholipid standards was 0.5 g/mL. ;
- the extract is a chloroform/methanol solution containing dibutylhydroxytoluene, the volume ratio of the chloroform/methanol is 1:1, and the mass fraction of the dibutylhydroxytoluene is 0.005%;
- the storage solution is a chloroform/methanol solution containing dibutylhydroxytoluene, the volume ratio of the chloroform/methanol is 1:1, and the mass fraction of the dibutylhydroxytoluene is 0.005%;
- the sample added with the phospholipid standard obtained in the step (5) was detected by LC-MS, and the molecular structure and content data of the phospholipid group in the passage process of the vitamin C producing strain were obtained; LC-MS detection conditions are the same as in Example 4-1;
- the molecular content data of the phospholipid group in the process of passage of the vitamin C production strain obtained in the step (6) were subjected to multivariate statistical analysis to obtain differential phospholipid molecular markers for distinguishing the vitamin C producing strains in different passage times; the multivariate statistical analysis method was Pareto pretreatment. Principal component analysis
- the content of the differential phospholipid molecular markers obtained in step (7) is plotted according to different passage times, and the changes of these brick lipid molecules are observed and analyzed, and the phospholipid molecules which play a key role in the subculture process of mixed bacteria and related are found.
- the metabolic pathway provides direction for strain modification and optimization of culture conditions for the purpose of improving 2-keto-L-gulonic acid.
- a method for analyzing changes in phospholipid groups during the passage of vitamin C production strains the characteristics of which include the following steps:
- the Bacillus megaterium and Gluconobacter oxydans cultured in the step (1) were separately transferred to a seed culture medium, and cultured at 35 ° C, shaking at 280 rpm for 24 hours to obtain a Bacillus megaterus seed solution and a Gluconobacter oxydans seed solution. ;
- the three subculture strains obtained in the step (2) were streaked and purified, and then inoculated on a solid medium, and cultured at 35 ° C for 48 hours; and then transferred to a seed medium at 35 ° C, 280 rpm. Shake the shaker for 24h to obtain the evolved Bacillus megaterium seed solution and the evolved Gluconobacter oxydans seed solution;
- the evolved Bacillus megaterium, the evolved Gluconobacter oxydans, and the mixed evolved Bacillus megaterium and the evolved Gluconobacter oxydans were respectively inoculated into a fermentation medium to make the evolved Bacillus megaterium
- the density is 2xl0 1G cfu / mL
- the density of the evolved Gluconobacter oxydans is 2xlO u cfu / mL
- step 2 The cells obtained in step 1 were ground in a mortar using liquid nitrogen to prepare a dry powder, and 300 mg of the cell dry powder was weighed, placed in a centrifuge tube A, and 0.8 mL of ultrapure water was added thereto, and thoroughly mixed;
- step 3 Repeat step 3 4 times until the cells are completely settled
- the total phospholipid extraction mixture is dissolved in 2 mL of the stock solution to prepare a sample, and stored at -40 ° C or below;
- a phospholipid standard was added to the sample, and the phospholipid standards were mercaptoacylphosphatidylglycerol, bis-decanoylphosphatidylethanolamine and bis-dodecanoylphosphatidic acid, so that the three phospholipid standards were finalized.
- the concentration is 1.5 g/mL;
- the extract is a chloroform/methanol solution containing dibutylhydroxytoluene, the volume ratio of the chloroform/methanol is 2:1, and the mass fraction of the dibutylhydroxytoluene is 0.01%;
- the storage solution is a chloroform/methanol solution containing dibutylhydroxytoluene, the volume ratio of the chloroform/methanol is 4:1, and the mass fraction of the dibutylhydroxytoluene is 0.01%;
- the sample obtained by the step (5) and added with the phospholipid standard was detected by LC-MS, and the molecular structure and content data of the phospholipid group in the passage process of the vitamin C producing strain were obtained;
- the molecular content data of the phospholipid group in the process of passage of the vitamin C production strain obtained in the step (6) were subjected to multivariate statistical analysis to obtain differential phospholipid molecular markers for distinguishing the vitamin C producing strains in different passage times; the multivariate statistical analysis method was Pareto pretreatment. Principal component analysis
- the content of the differential phospholipid molecular markers obtained in step (7) is plotted according to different passage times, and the changes of these brick lipid molecules are observed and analyzed, and the phospholipid molecules which play a key role in the subculture process of mixed bacteria and related are found.
- Metabolic pathway It provides direction for strain modification and optimization of culture conditions for the purpose of improving 2-keto-L-gulonic acid.
- Examples 4-2 and 4-3 are similar to the results of Example 4-1.
- the composition of the solid medium, the seed medium, and the fermentation medium used in the present invention is selected from the medium disclosed in Chinese Patent Application No. 201110314740.9, for example:
- Solid medium weigh 20 g of L-xanthine, 3 g of corn syrup, 3 g of beef bone, 3 g of yeast dipping powder, 1 g of urea, 10 g of peptone, 20 g of agar, 20 g of agar, KH 2 P0 4 1 g , MgS0 4
- a method for detecting a change in a nutrient environment during the passage of a vitamin C producing strain comprises the following steps:
- Gluconobacter oxydans stored in a volumetric 15% glycerol aqueous solution and 500 Bacillus megaterium deposited in a 15% by volume aqueous solution of glycerol in liquid nitrogen were inoculated separately. On the medium, 28 ° C, culture for 24 h; 2 seed culture:
- the Bacillus megaterium and Gluconobacter oxydans cultured in the step (1) 1 were separately transferred to a seed medium at 28. C, 200 r / min shaker shaking culture for 24h, obtaining Bacillus megaterium seed solution and Gluconobacter oxydans seed solution;
- Bacillus megaterium and Gluconobacter oxydans were inoculated into a new seed medium such that the density of Bacillus megaterium was 2 x 10 7 CFU/mL, and the density of Gluconobacter oxydans was 2 x 10 8 CFU/mL, at 28.
- C 200 r / min shaker shaking culture, 24h as the passage cycle, the volume ratio of 1% for the passage ratio into the new seed medium, passaging 150 days to obtain mixed cells, in the passage of 0-150 days
- Four sampling times were selected for 0 days, 50 days, 100 days, and 150 days, respectively.
- the four mixed cells obtained in the step (1) 2 were streaked and purified, and then inoculated on a solid medium, and cultured at 28 C for 24 h; and then transferred to a new seed medium at 28 ° C, respectively.
- the Bacillus megaterium seed solution and the Gluconobacter oxydans seed solution were respectively obtained; and the solution was stored in a glycerin aqueous solution having a volume concentration of 15%;
- the Bacillus megaterium and Gluconobacter oxydans obtained in the step (1) 3 and the mixed bacteria in which the two bacteria are mixed together are inoculated into a new seed medium to make the density of Bacillus megaterium 2x10 7 CFU/mL.
- the density of Gluconobacter oxydans is 2x10 8 CFU/mL, at 28. C, 200 r / min shaker shaking culture for 10 h;
- the color column has a specification of 30 mx0.25 mm i.d. and an inlet temperature of 250.
- the carrier gas is high purity helium
- the flow rate is 0.6 ml/min
- the split ratio is 3: 1
- the column oven temperature rise procedure is: initial 50.
- C keep 2 min, to 4.
- the speed of C/min rose to 260.
- the score map and load map for expressing the similarity and difference are obtained.
- the closer the sample points are to each other the larger the similarity of the samples is, and the farther the distance is, the larger the sample difference is.
- each point represents the nutrient composition, the farther away from the center point
- the difference in the process of subculture is greater, and it can be used as a subculture to cultivate nutrient environment changes. Markers; see Figure 18, Figure 20 and Figure 22.
- Glycerol asparagine uric acid inositol glycerol As shown in Table 5-1, 74 kinds of nutrient environmental substances in the process of passage of vitamin C production strain (Gluconobacter oxydans) were detected by the method of the present invention, among which 11 kinds of sugar and 20 kinds of amino acid There are 9 kinds of sugar derivatives, 21 kinds of organic acids, 2 kinds of fatty acids, 11 kinds of other substances such as amines and nitrogen-containing compounds.
- Glycerol asparagine uric acid inositol hypoxanthine as shown in Table 5-2 by the method of the present invention, a total of 74 kinds of nutrient environmental substances were detected in the process of passage of the vitamin C producing strain (Bacillus megaterium), among which 11 kinds of sugar, amino acid 20 kinds, 8 kinds of sugar derivatives, 22 kinds of organic acids, 2 kinds of fatty acids, 11 kinds of other substances such as amines and nitrogen compounds.
- Glycerol asparagine uric acid inositol hypoxanthine as shown in Table 5-3, by the method of the present invention, a total of 77 kinds of nutrient environmental substances in the process of mixing and mixing vitamin C production strains were detected, among which 11 kinds of sugars and 20 kinds of amino acids.
- Sugar derivation There are 9 kinds of substances, 24 kinds of organic acids, 2 kinds of fatty acids, 11 kinds of other substances such as amines and nitrogen-containing compounds.
- FIG. 18 The relative content of nutrient environmental substances subcultured by 0, 50, 100 and 150 generations of Gluconobacter oxydans was sample matrix, and principal component analysis was performed (Fig. 18).
- the score maps can be clearly divided into four categories, and the load maps are displayed.
- Figure 19 is a graph showing the relative content changes of molecular markers for different passage times, wherein valine, isoleucine, valine, acetyl acid, alanine, serine, 5-ketoproline, butyric acid And tryptophan increased with the passage of time, and higher than the blank medium, which is the result of the degradation of proteins by Gluconobacter oxydans.
- the accumulation of these substances provided sufficient nutrition for the growth of large bacteria.
- the relative content of nutrient environmental substances subcultured by Bacillus megaterium at 0, 50, 100 and 150 generations is a sample matrix, and principal component analysis is performed.
- the score maps can be effectively divided into four categories, in the load map.
- the five molecular markers are sequentially distributed in the direction of the first principal component, indicating a tendency of these markers to gradually change as the algebra increases.
- Figure 21 shows the trend of the relative content of molecular markers in the culture environment of Bacillus megaterium in different passage times. Except for erythrose and 4-hydroxyproline, the content of other marker molecules is lower than that of blank medium. We can think that they can be used by big bacteria for growth and synthesis of their own substances.
- the content of proline and glycine decreased gradually, especially in the culture environment of 150 generations of large bacteria, which was significantly lower than that of the original strain. Accumulation of more proline in the large bacteria helps to resist environmental stress; glycine plays an important role in the cell membrane, and high concentration of glycine helps to increase the permeability of the cell membrane. As the passage increases, the large bacteria on the scent The acid utilization ability is enhanced, which facilitates the dry release of the intracellular metabolites of the large bacteria in the mixed culture, thereby promoting the synthesis of 2-KLG.
- the concentration of erythrose and 4-hydroxyproline in the culture environment was higher than that in the blank medium, which showed that they were the extracellular accumulation of large bacteria, and the concentration of these two marker molecules gradually increased with the passage time. It reached its maximum in the passage of 150 generations of large bacteria.
- Akasaka Sugar is a synthetic precursor of aromatic amino acids and vitamin B 6 , which can help oxidize Gluconobacter to synthesize acid and improve carbon center metabolism.
- the mixed cells were subjected to principal component analysis based on the relative content of the substances in the mixed nutrient environment at the passage time of 0, 50, 100 and 150 days.
- the score chart shows that the mixed bacteria of 50 and 100 generations were compared. Close, the 0-generation mixed bacteria is clearly distinguished from the evolved mixed bacteria.
- a method for detecting a change in a nutrient environment during the passage of a vitamin C producing strain comprises the following steps:
- Gluconobacter oxydans deposited in a 10% volume aqueous solution of glycerol and 10 Bacillus megaterium deposited in a 20% by volume aqueous solution of glycerol in liquid nitrogen were inoculated separately. On the medium, 30 ° C, culture for 36 h;
- the Bacillus megaterium and Gluconobacter oxydans cultured in the step (1) 1 were separately transferred to a seed medium at 30°C. C, 250 r / min shaker shaking culture for 36h, respectively, to obtain Bacillus megaterium seed solution and Gluconobacter oxydans seed solution; Bacillus megaterium and Gluconobacter oxydans were inoculated into a new seed medium such that the density of Bacillus megaterium was 2 x 10 8 CFU/mL, and the density of Gluconobacter oxydans was 2 x 10 9 CFU/mL at 30.
- the three mixed cells obtained in the step (1) 2 were streaked and purified, and then inoculated on a solid medium, and cultured at 30 C for 36 h; and then transferred to a new seed medium at 30 ° C, respectively. After shaking for 36 h at 250 rpm shaker, the Bacillus megaterium seed solution and the Gluconobacter oxydans seed solution were respectively obtained; and stored in a 20% volume aqueous solution of glycerin;
- the Bacillus megaterium and Gluconobacter oxydans obtained in the step (1) 3 and the mixed bacteria in which the two bacteria are mixed together are inoculated into a new seed medium to make the density of Bacillus megaterium 2x10 8 CFU/mL. , the density of Gluconobacter oxydans is
- the filtrate 20 obtained in the step (2) 1 is placed in a centrifuge tube, and 100 of 0.10 mg/ml yttrium-labeled succinic acid methanol solution is added as an internal standard, and lyophilized; 80 is added at a concentration of 20 mg/mL.
- a solution of oxyamine hydrochloride in pyridine was at 37. "Chemical reaction 90 mill in C water bath; add 80 ⁇ -methyl-N-trimethylsilane trifluoroacetamide At 37. Silanization reaction in a C water bath for 40 min;
- the color column has a specification of 30 mx0.25 mm i.d. and an inlet temperature of 270.
- the carrier gas is high purity helium
- the flow rate is 0.8 ml/min
- the split ratio is 20: 1
- the column temperature riser is: initial 60. C, keep 3 min, to 6.
- the speed of C/min rose to 280.
- the relative content of the differential nutrient environmental markers is plotted according to different passage times, and the laws of the changes of these substances are observed and analyzed, and then the nutrient environment components that play a key role in the subculture process of the mixed bacteria are found, thereby revealing the mixed culture of the mixed bacteria.
- the interaction mechanism and optimization of culture conditions between the two bacteria provide the direction.
- a method for detecting a change in a nutrient environment during the passage of a vitamin C producing strain comprises the following steps:
- Gluconobacter oxydans stored in liquid nitrogen at a concentration of 30% in glycerol aqueous solution and 200 Bacillus megaterium deposited in a 30% by volume aqueous solution of glycerol were inoculated separately. On a solid medium, cultured at 35 ° C for 48 h;
- the Bacillus megaterium and Gluconobacter oxydans cultured in the step (1) 1 were separately transferred to a seed medium at 35°C. C, 280 r / min shaker shaking culture for 48 h, obtaining Bacillus megaterium seed solution and Gluconobacter oxydans seed solution;
- the Bacillus megaterium and Gluconobacter oxydans was inoculated into a new seed medium, the density of the Bacillus megaterium is 2xlO ie CFU / mL, so that the density is Gluconobacter oxydans 2xlO u CFU / mL, at 35. C, 280 r / min shaker shaking culture, 48h as the passage cycle, with a volume ratio of 10% for the passage ratio into the new seed medium, selected 4 sampling time in the 0-150 days of passage to take 4 The same, respectively, 0 days, 50 days, 100 days, 150 days;
- the four mixed cells obtained in the step (1) 2 were streaked and purified, and then inoculated separately on a solid medium, 35. C culture for 48 h; then transfer to new seed culture medium, shake culture at 280 rpm for 48 h at 35 ° C, respectively, to obtain Bacillus megaterium seed solution and Gluconobacter oxydans seed solution; preserved in a volume concentration of 30 % in glycerol in water;
- the mixing step (1) 3 obtained from Bacillus megaterium and Gluconobacter oxydans strain as well as two strains were mixed together inoculated into seed medium, so that the density of Bacillus megaterium 2xl0 1G CFU / mL, Gluconobacter The density of the bacillus is 2x10 U CFU/mL at 35. C, 280 r / min shaker shaking culture for 15h;
- the filtrate 50 obtained in the step (2) 1 was placed in a centrifuge tube, and 200 0.14 mg/ml yttrium-labeled succinic acid methanol solution was added as an internal standard, and lyophilized; 100 was added at a concentration of 20 mg/mL.
- the pyridine solution of oxyamine hydrochloride is at 40. In the C water bath, the reaction was carried out for 120 min; then 100 ⁇ -methyl-N-trimethylsulfonyltrifluoroacetamide was added to the silylation reaction in a water bath at 40 ° C for 60 min;
- the color column has a specification of 30 mx 0.25 mm id and an inlet temperature of 280.
- the carrier gas is high purity helium
- the flow rate is 0.7 ml/min
- the split ratio is 5: 1
- the column temperature rise program is: initial 80. C, keep 5 min, to 8. The speed of C/min rose to 300.
- Example 5-2 and Example 5-3 are similar to the results of Example 5-1.
- the composition of the solid medium and the seed medium used in the present invention is selected from the medium disclosed in Chinese Patent Application No. 201110314740.9, for example:
- Solid medium weigh 20 g of L-xanthine, 3 g of corn syrup, 3 g of beef bone, 3 g of yeast dipping powder, 1 g of urea, 10 g of peptone, 20 g of agar, 20 g of agar, KH 2 P0 4 1 g , MgS0 4
- Example 6-1
- a method for analyzing changes in small molecule metabolites during the passage of a vitamin C producing strain which is characterized by the following steps:
- the Bacillus megaterium and Gluconobacter oxydans cultured in the step (1) 1 were separately transferred to a seed culture medium, and shake cultured at 30, 240 rpm for 36 h, respectively, to obtain a Bacillus megaterus seed solution and a Gluconobacter oxydans seed solution. ;
- the four mixed cells obtained in the step (1) 2 were streaked and purified, and then inoculated on a solid medium, 30 cells for 36 hours; and then transferred to a new seed medium, respectively, at 30* ⁇ , 240
- the cultured Bacillus megaterium seed solution and Gluconobacter oxydans seed solution were respectively obtained by shaking with a rpm shaker for 36 h; and stored in an aqueous solution of glycerin having a volume concentration of 20%; 4 fermentation:
- the evolved Bacillus megaterium and Gluconobacter oxydans obtained in the step (1) 3 and the mixed bacteria in which the two bacteria are mixed together are inoculated into a new seed medium to increase the density of the evolved Bacillus megaterium.
- the density of the evolved Gluconobacter oxydans was 2xl0 1G CFU/mL, and cultured at 30* ⁇ , shaking at 240 rpm for 13 h;
- the cells obtained in the step (2) 1 were prepared into a dry powder by liquid nitrogen grinding, and 50 mg of the cell dry powder were weighed and placed in three centrifuge tubes, and then 1.0 mL of the extract was added thereto, and the concentration of 50 ⁇ was 0.040 mg/ The mL ⁇ labeled succinic acid methanol solution was used as an internal standard, and mixed; 2000 111 was centrifuged 5 111111, and the supernatant was placed in three new centrifuge tubes and lyophilized;
- Step (2) 2 to obtain three centrifugation tubes, respectively, add 50 methamine hydrochloride pyridine solution in a concentration of 20 m g / mL in a 30 water bath for 90 min; add 80 L N- Methyl-N-trimethylsilane trifluoroacetamide was subjected to a silylation reaction in a 37 water bath for 30 min;
- the extract is an aqueous methanol solution having a volume fraction of 50;
- the sample obtained in the step (2) 3 is introduced into the gas phase color, the column is DB-5MS, and the color column is 3 111 ⁇ 30 111 > 0.25 111111 1.
- the inlet temperature is 280
- the carrier gas is high-purity helium, constant pressure 91KPa, split ratio 10: 1
- column oven temperature program is: initial 70* ⁇ , hold for 5 min, rise to 280 at 5/min for 5 min, use EI ionization Source, source temperature 250, detector voltage 2500V, ionization voltage 70 eV, Current 40 ⁇ ; mass transfer detection range 50-800 m/z; identification of small molecule metabolites using NIST 2005 database, mass spectrometry data processing and metabolite relative content determination using Masslynx 4.1 software; and by color peak area integration Treating, and comparing with the peak area of the internal standard, obtaining the relative content of small molecule metabolites;
- the content of small molecule metabolite markers was graphed according to different passage times, and the changes of small molecule metabolite markers were observed and analyzed, and the changes of intracellular small molecule metabolites during the passage of vitamin C producing strains were detected. Furthermore, metabolite molecules and related metabolic pathways that play a key role in the subculture of mixed bacteria are discovered, in order to reveal the interaction mechanism of the two bacteria during the subculture of the mixed bacteria and to improve 2-keto-L-gulonic acid. The strains are modified and the culture conditions are optimized to provide direction.
- FIG. 24 The relative content of small molecule metabolites subcultured with Gluconobacter oxydans of 0, 50, 100 and 150 generations was a sample matrix and principal component analysis was performed (Fig. 24).
- the score map (Fig. 24-1) can be clearly divided into four categories, of which 150 generations are obviously far from the metabolite spectrum of 0, 50 and 100 generations, and 0 generations are close to 50 generations, indicating that the evolutionary differences are not Very big.
- Figure 25 is a graph showing the relative content changes of molecular markers for different passage times of Gluconobacter oxydans.
- the content of palmitic acid, oleic acid and octadecanoic acid decreased with the passage time, indicating that the cells were consumed during growth. More fatty acids produce cell membrane phospholipids, so free fatty acids are significantly reduced after 100 passages.
- FIG. 26 is a graph showing the trend of the change in the relative content of small molecule metabolic markers of Bacillus megaterium over time in different passage times. Among them, palmitic acid and octadecanoic acid decreased significantly with the prolongation of the passage time of Bacillus megaterium, indicating that cell growth consumes more fatty acids to produce cell membrane phospholipids, so free fat is reduced. In addition, most of the amino acids, such as proline and 4-hydroxyproline, are significantly reduced, 5-oxo It also shows that Bacillus megaterium consumes a large amount of acid to maintain its own growth and synthesize intracellular proteins.
- FIG. 28 Principal component analysis was performed on the sample matrix using the relative content of small molecule metabolites at 0, 50, 100, and 150 days of the mixed cells (Fig. 28).
- the score map (Fig. 28-1) showed 0 generations and 50s.
- the mixed samples of 100 and 150 generations were clearly distinguished, indicating that the mixed evolution of the strain system was significantly different from that of the original starting bacteria system during the subculture of the mixed bacteria, but the 50th and 100th generations were closer.
- the first principal component cannot be clearly distinguished.
- Figure 29 is a graph showing the trend of the relative content of small molecule metabolite markers mixed in different passage times.
- a method for analyzing changes in small molecule metabolites during the passage of a vitamin C producing strain comprising the following steps:
- the Bacillus megaterium and Gluconobacter oxydans cultured in the step (1) 1 were separately transferred to a seed culture medium, and shake cultured at 28, 200 rpm for 48 hours, respectively, to obtain a Bacillus megaterus seed solution and a Gluconobacter oxydans seed solution. ;
- the three mixed cells obtained in the step (1) 2 were streaked and purified, and then inoculated on a solid medium, respectively, for 28 hours; then transferred to a new seed medium, and shaken at 28, 200 rpm. After shaking for 48 h, the evolved Bacillus megaterium seed solution and Gluconobacter oxydans seed solution were separately obtained; they were stored in a glycerin aqueous solution having a volume concentration of 15%;
- the evolved Bacillus megaterium and Gluconobacter oxydans obtained in the step (1) 3 and the mixed bacteria in which the two bacteria are mixed together are inoculated into a new seed medium to increase the density of the evolved Bacillus megaterium.
- the density of the evolved Gluconobacter oxydans was 2 ⁇ 10 8 CFU/mL, and cultured at 28* ⁇ , 200 rpm shaker for 15 h;
- the cells obtained in the step (2) 1 were made into a dry powder by grinding the cells with liquid nitrogen, and 30 mg of the cell dry powder were weighed and placed in three centrifuge tubes, and 0.5 mL of the extract was added thereto, and the concentration of 30 ⁇ was 0.020 mg. /mL ⁇ labeled succinic acid methanol solution as internal standard, mix; 1000 111 centrifugation 10 111111, take the supernatant in three new centrifuge tubes and freeze-dry;
- step (2) 2 to the three centrifuge tubes to add 40 to the concentration
- the extract is an aqueous methanol solution having a volume fraction of 70%
- the sample obtained in the step (2) 3 is introduced into the gas phase color, the column is DB-5MS, and the color column is 3 111 ⁇ 30 111 > 0.25 111111 1.
- the inlet temperature is 250
- the carrier gas is high-purity helium, constant pressure 80KPa, split ratio 3: 1
- the column temperature rise program is: initial 50* ⁇ , hold for 3 min, rise to 260 at 4/min, hold for 3 min, use EI ionization Source, source temperature detector voltage 2300 V, ionization voltage 60 eV, current 30 ⁇ ; mass transfer detection range 50-800 m/z; identification of small molecule metabolites using NIST 2005 database, mass spectrometry data processing and relative metabolite content
- the measurement was performed using Masslynx 4.1 software; and the relative content of small molecule metabolites was obtained by integrating the peak area of the color peak and comparing with the peak area of the internal standard;
- the content of small molecule metabolite markers was graphed according to different passage times, and the changes of small molecule metabolite markers were observed and analyzed, and the changes of intracellular small molecule metabolites during the passage of vitamin C producing strains were detected.
- a method for analyzing changes in small molecule metabolites during the passage of a vitamin C producing strain comprising the following steps:
- Gluconobacter oxydans stored in liquid nitrogen at a concentration of 30% in glycerol aqueous solution and 500 Bacillus megaterium deposited in a 30% by volume aqueous solution of glycerol were inoculated separately. On a solid medium, culture 24;
- the Bacillus megaterium and the Gluconobacter oxydans cultured in the step (1) 1 were respectively transferred into a seed culture medium, and shake cultured at 35, 280 rpm for 24, respectively, to obtain a Bacillus megaterium seed liquid and a Gluconobacter oxydans seed liquid;
- the four mixed cells obtained in the step (1) 2 were streaked and purified, and then inoculated on a solid medium, respectively, and cultured for 35 hours; and then transferred to a new seed medium at 35* ⁇ , 280, respectively.
- the cultured Bacillus megaterium seed solution and Gluconobacter oxydans seed solution were respectively obtained by shaking with a rpm shaker for 24 h; and stored in a 30% volume aqueous solution of glycerin;
- the evolved Bacillus megaterium and Gluconobacter oxydans obtained in the step (1) 3 and the mixed bacteria in which the two bacteria are mixed together are inoculated into a new seed medium to increase the density of the evolved Bacillus megaterium.
- the density of the evolved Gluconobacter oxydans is 2 ⁇ 10 U CFU/mL, and shaken at 35* ⁇ , shaking at 280 rpm for 10;
- the cells obtained in the step (2) 1 were ground into a dry powder by grinding the cells with liquid nitrogen, and 60 mg of the cell dry powder were weighed and placed in three centrifuge tubes, and 1.5 mL of the extract was added thereto, and the concentration of 70 ⁇ was 0.060 mg. /mL ⁇ labeled succinic acid methanol solution as internal standard, mix; 3000 111 centrifugation 3 111111, take the supernatant in three new centrifuge tubes and freeze-dry;
- Step (2) 2 to obtain three centrifugation tubes, respectively, add 100 methamine hydrochloride pyridine solution at a concentration of 30 m g / mL in a 40 water bath for 120 min; then add ⁇ ⁇ - ⁇ The silylation reaction of hydrazinyl-trimethylacetate in a 40 water bath for 60 min;
- the extract is an aqueous methanol solution having a volume fraction of 60%; 4 GC-TOF/MS detection:
- the sample obtained in the step (2) 3 is introduced into the gas phase color, the column is DB-5MS, and the color column is 3 111 ⁇ 30 111 > 0.25 111111 1.
- the inlet temperature is 280
- the carrier gas is high-purity helium, constant pressure 100KPa, split ratio 20: 1
- the column temperature rise program is: initial 80* ⁇ , hold for 6 min, increase to ⁇ / ⁇ to 300* ⁇ , hold for 8 min, use EI ionization source, source temperature 260* ⁇ , detector voltage 2700V, ionization voltage 80 eV, current 50 ⁇ ; mass transfer detection range 50-800 m/z; identification of small molecule metabolites using NIST 2005 database, mass spectrometry data processing
- the relative content of metabolites was determined using Masslynx 4.1 software; and the relative content of small molecule metabolites was obtained by integrating the peak area of the color peaks and comparing with the peak area of the internal standard;
- the content of small molecule metabolite markers was graphed according to different passage times, and the changes of small molecule metabolite markers were observed and analyzed, and the changes of intracellular small molecule metabolites during the passage of vitamin C producing strains were detected.
- Example 6-2 and Example 6-3 are similar to those of Example 6-1.
- the composition of the solid medium and the seed medium used in the present invention is selected from the medium disclosed in Chinese Patent Application No. 201110314740.9, for example:
- the strain Bacillus megaterium CGMCC No 1.459 and Gluconobacter oxydans used in the present invention are used.
- CGMCC No 1.110 is for illustrative purposes only, but is not intended to limit the invention. It is to be understood that other strains of Bacillus megaterium and Gluconobacter oxydans can also be used in the present invention.
- Example 7
- Gluconobacter oxydans containing a gene encoding a kaempferol dehydrogenase gene to improve the fermentation performance of 2-keto-L-gulonic acid mixed bacteria. It is characterized by the following steps:
- the bacterial genome extraction kit was used to extract the genome of Gluconobacter oxydans; the genomic solution 1 ⁇ 1, 5xFastPfu buffer 4 ⁇ 1, 20mM dNTP 2 ⁇ 1, 20 ⁇ primer 1 0.4 ⁇ 1, 20 ⁇ primer 2 0.4 ⁇ 1, sterile water 11.8 ⁇ 1, FastPfu Enzyme 0.4 ⁇ 1, mixed evenly in the PCR tube; PCR cycle; ⁇ PCR instrument for amplification cycle, the amplification procedure is: 95. C 2min; 95 ° C 20s, 55 ° C 35s, 72 ° C 2min, a total of 25 cycles; 72 ° C 5min; C 30min.
- the PCR product was subjected to agarose gel electrophoresis, and the PCR product strip was excised, and the PCR amplification product was purified by an agarose gel recovery kit.
- the sequence of the primer 1 is: 5,-CCCAAGCTTGACTGGCAGCAGCGCAAC-3'
- the sequence of the primer 2 is: 5,-
- the ligation product was transformed into Escherichia coli DH5 (x, chemically transformed, coated on LB solid medium containing antibiotics, and cultured at 37 C for 12 h.
- the single colony obtained after the culture was in LB liquid medium 37.
- the plasmid was extracted with a plasmid miniprep kit to obtain a gene encoding the kaempferol dehydrogenase gene.
- Gluconobacter oxidans was coated on solid medium at 30. C culture for 48 hours; wash the cells with 2 ml of sterile water, water bath for 10 min, 4. C, centrifuge at 5 rpm for 5 min, collect the cells, wash once with pre-cooled sterile water, wash twice with 10% glycerol, resuspend the cells with ⁇ 10% glycerol; and obtain the kaempferol dehydrogenase gene vector obtained from step (2).
- the aqueous solution was uniformly mixed in an electric rotor, and the ice bath was placed for 5 minutes.
- the electric rotor was placed in a 1800V electric shock in the electrorotation apparatus; the electroshock product was uniformly mixed with the 900 ⁇ l seed medium at 30.
- the solid medium is: L-mountain 20 g , corn syrup 3 g , beef bone 3 g , yeast dip powder 3 g, urea lg, peptone 10 g, agar 20 g, KH 2 P0 4 lg, MgSO 4 0.2 g, CaC0 3 lg, add water to 1L, adjust pH to 6.8, 121. C sterilized for 20 min.
- the seed medium is: L-mountain 20 g , corn syrup 3 g , beef bone 3 g , yeast dipping powder 3 g, urea lg, peptone 10 g, KH 2 P0 4 lg, MgSO 4 0.2 g, CaC0 3 lg Add water to 1L and adjust pH to 6.8, 121. C sterilized for 20 min.
- the Gluconobacter oxydans and Bacillus megaterium containing the vector encoding the kaempferol dehydrogenase gene obtained in the step (3) are inoculated into a fermentation medium to obtain Gluconobacter oxydans containing a gene encoding a kaempferol dehydrogenase gene.
- the density is 4x10 8 cfu/ml
- the density of Bacillus megaterium is 4x10 8 cfu/ml at 30.
- C cultured at 250 rpm for 120 h to obtain 2-keto-L-gulonic acid.
- the fermentation medium is: Weigh 80g of L-wheat sugar, 20g of corn syrup, 12g of urea, 12g of urea, KH 2 P0 4 lg, 0.5g of MgSO 4 , CaC0 3 lg, add water to 1L, adjust the pH to 7.0, 121 . C sterilized for 20 min.
- HPLC High performance liquid chromatography
- Sample preparation Take 1 mL of fermentation broth at different times in a 1.5 mL centrifuge tube, centrifuge at 10000 r/min for 3 min, take the supernatant ⁇ in a 1.5 mL centrifuge tube, and add 900 ⁇ M ⁇ 2 phase (5 mM H 2 S0 4 ) A sample that is ten times dry is obtained. After oscillating and mixing, the sample was filtered through a 0.22 ⁇ m cellulose microporous membrane to obtain a sample to be tested.
- High performance liquid chromatography conditions Color column: bio-rad HPX-87H, mobile phase: 5 mM H 2 S0 4 , flow rate: 0.6 mL/min, column temperature: 65. C, the differential detector.
- Example 7-1 The test results are shown in Fig. 30.
- ⁇ Original fermentation of Gluconobacter oxydans and Bacillus megaterium
- ⁇ Mixed fermentation of Gluconobacter oxydans and Bacillus megaterium containing the gene encoding the swainone dehydrogenase gene.
- Example 7-1 The original Gluconobacter oxydans and Bacillus megaterium using the steps (7-1) of Example 7-1
- the yield of 2-keto-L-gulonic acid in the fermentation condition was 87% with the fermentation conditions; the Gluconobacter oxydans containing the gene encoding the kaempferone dehydrogenase gene obtained by the method of Example 7-1 and the huge The yield of 2-keto-L-gulonic acid fermented by Bacillus mixed bacteria reached 98%; the yield of 2-keto-L-gulonic acid was increased by 12.6%.
- Example 8-1 The yield of 2-keto-L-gulonic acid in the fermentation condition was 87% with the fermentation conditions; the Gluconobacter oxydans containing the gene encoding the kaempferone dehydrogenase gene obtained by the method of Example 7-1 and the huge The yield of 2-keto-L-gulonic acid fermented by Bacillus mixed bacteria reached 98%; the yield of 2-keto-L-gulonic acid was increased by 12.
- a method for detecting changes in intracellular proteins of glutathione during the action of Gluconobacter oxydans comprising the steps of:
- 3 parts of Gluconobacter oxydans were inoculated into the fermentation medium A in a volume ratio of 8%, and 3 parts of the Gluconobacter oxydans were inoculated into the fermentation medium B at a volume ratio of 8%, respectively.
- the medium after inoculation was at 28.
- C the fermentation is carried out at a rotation speed of 200 rpm, and the fermentation broth sample is taken at 1 h and 15 h in the fermentation process, at 4.
- Centrifuge at 4000 rpm collect the lower layer of cells, wash with phosphate buffer of pH 7.2, immediately quench with liquid nitrogen, terminate the metabolic reaction; use liquid nitrogen to grind the cells to obtain 3 parts.
- the quenched and disrupted cells were collected by fermentation in medium A for 1 h, 3 parts of the crushed cells were collected from medium A for 15 h, and 3 parts were fermented from medium B for 1 h to collect the quenched broken cells, 3 parts from The quenched broken cells were collected by fermentation in medium B for 15 h;
- A is the fermentation medium: SO gL- 1 Sugar Hill Qian O gL 1 corn steep liquor, 1 g * L 1 KH 2 P0 4, 0.2 g * L 1 MgS0 4, ⁇ 12 g * L 1 of urea, with the balance water;
- the enzyme medium B is: 80 1 hawthorn O g'L 1 corn syrup, 1 gL 1 KH 2 P0 4 , 0.2 gL 1 MgS0 4 , and 12 g*L 1 urea, 0.8 ⁇ 1.5 mg*mL 1 glutathione, the balance is water;
- the cell lysate is: 8 mol-L 1 urea, 4% by mass of (3-[(3-cholamidopropyl)-diethylamine]-propanesulfonic acid) (CHAPS), 40 mM Tris , the balance is water;
- the bovine serum albumin was added from the low concentration to the high concentration into the Coomassie Brilliant Blue G-250 solution, and the absorbance at each protein obtained in step 2 was determined to establish a standard curve; the protein protein of each protein solution was determined. concentration;
- the solution obtained in the step solution 6 is mixed to obtain 3 parts of the mixed solution, and each mixed solution includes the labeled protein which is obtained by the fermentation of the crushed cells from the medium A for 1 h, and the obtained step 2-6, from the culture.
- the crushed cells in the base A were collected for 15 h, and the labeled proteins obtained after the steps 2-6 were collected, and the quenched broken cells were collected from the medium B for 1 h to collect the labeled proteins obtained after the steps 2-6.
- the labeled protein was obtained by fermentation of the crushed cells from the medium B for 15 h and then after the steps 2-6; C save;
- the mixed solution obtained in 7 was subjected to Q-Tof mass identification to obtain a protein spectrum, and differentially expressed proteins of each mixed group sample were obtained by quantitative determination;
- step (1)8 Using matlab to normalize the data obtained in step (1)8, perform principal component analysis to obtain data categories with different changes ⁇ , and obtain candidate differential proteins;
- the candidate differential protein content obtained in step (2) was plotted according to time series, and the regularity of these protein changes was observed and analyzed, and then glutathione was found to increase the production of 2-keto-L-gulonic acid by Gluconobacter oxydans. The role. After the addition of glutathione, the intracellularly identified proteins in the fermentation of Gluconobacter oxydans are shown in Table 1. Gluconobacter oxydans intracellular protein
- Ribosomal protein S8 family protein single-stranded DNA-binding protein (SSB) S8 family protein single-stranded DNA-binding protein
- NADH NADH-dependent enoyl-ACP reductase 1
- ribosomal protein L5 BL6
- cold shock protein cspB Major cold shock protein
- Ribosom protein L24 sorbose/sorbosone dehydrogenase ribosomal protein S17 family protein trigger factor
- BL4 ribosomal protein L4 (BL4) cyclophilin type peptidyl-prolyl cis-trans isomerase/CLD family protein
- Double-strand break repair protein AddB bacterial extracellular solute-binding family protein
- DNA-binding protein HU 1 DNA-binding cobaltochelatase, CobS subunit
- NAD(P)H q uinone oxidoreductase transaldolase
- Glutathione S-transferase C-terminal bacterial extracellular solute-binding domain protein proteins, family 5 Middle family protein binding-protein-dependent transport system H-NS histone family protein
- acetyl-CoA carboxylase carboxyl N-6 DNA Methylase family protein transferase, beta subunit
- Glutamine synthetase catalytic domain transketolase Cold-shock DNA-binding domain protein conserved hypothetical protein lysyl-tRNA synthetase insulinase (Peptidase family Ml 6) family protein
- glutathione has a heavy effect on the growth of Gluconobacter oxydans and 2-keto-L-gulonic acid production, combined with related protein changes, growth curves and acid production, indicating that glutathione is beneficial.
- This finding provides a basis for subsequent genetic modification of Gluconobacter oxydans and provides a basis for research and control of industrial mixed bacteria processes.
- a method for detecting intracellular protein changes during the action of glutathione on Gluconobacter oxydans comprises the following steps:
- the quenched broken cells were collected in the base A for 1 h, 4 parts of the crushed cells were collected from the medium A for 15 h, and 4 parts of the crushed cells were collected from the medium B for 1 h, and 4 parts were cultured.
- the crushed cells were collected by fermentation in the base B for 15 h; the fermentation medium A and the fermentation medium B were the same as those in Example 8-1;
- the bovine serum albumin was added from the low concentration to the high concentration into the Coomassie Brilliant Blue G-250 solution, and the absorbance at each protein obtained in step 2 was determined to establish a standard curve; the protein protein of each protein solution was determined. concentration;
- each mixed solution includes the fermentation of the quenched broken cells from the medium A for 1 h, and the labeled protein obtained after the step 2-6, from the culture.
- the crushed cells in the base A were collected for 15 h, and the labeled proteins obtained after the steps 2-6 were collected, and the quenched broken cells were collected from the medium B for 1 h to collect the labeled proteins obtained after the steps 2-6.
- the labeled protein was obtained by fermentation of the crushed cells from the medium B for 15 h and then after the steps 2-6; C save;
- the mixed solution obtained in 7 was subjected to Q-Tof mass identification to obtain a protein spectrum, and differentially expressed proteins of each mixed group sample were obtained by quantitative determination;
- step (1) 8 After matricizing the data obtained in step (1) 8 with matlab, principal component analysis is performed to obtain data categories with different changes ⁇ , and candidate differential proteins are obtained;
- the candidate differential protein content obtained in step (2) was plotted according to time series, and the regularity of these protein changes was observed and analyzed, and then glutathione was found to increase the production of 2-keto-L-gulonic acid by Gluconobacter oxydans. The role.
- a method for detecting intracellular protein changes during the action of glutathione on Gluconobacter oxydans comprises the following steps:
- Gluconobacter oxydans were inoculated into the fermentation medium A at a volume ratio of 16%, and another 5 parts of the glucobacteria oxidizing bacteria were inoculated into the fermentation medium B at a volume ratio of 16%, respectively.
- the medium after inoculation was at 32.
- C culture fermentation under the condition of rotation speed of 250 rpm, take lh, 15 h as the point to take the fermentation liquid sample during the fermentation process.
- Centrifuge at 6000 rpm collect the lower layer of cells, wash with phosphate buffer of pH 7.4, quench with liquid nitrogen, terminate the metabolic reaction; crush the cells with liquid nitrogen to obtain 5 parts from medium A.
- the quenched broken cells were collected by fermentation for 1 h, 5 parts of the crushed cells were collected from the medium A for 15 h, and 5 parts were fermented from the medium B for 1 h to collect the quenched broken cells, and 5 parts from the medium B.
- the quenched broken cells were collected for 15 h in fermentation; the fermentation medium A and the fermentation medium B were the same as those in Example 8-1;
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Abstract
一种通过混菌进化传代培养和强化两菌相互作用以提高维生素C的前体2-酮基-L-古龙酸工业产量的方法,包括固体培养、种子培养、分纯和发酵的步骤。还包括利用所述混菌传代培养检测维生素C工业生产菌株过程中蛋白质、磷脂组、营养环境和小分子代谢物变化的方法。此外,本发明还包括含有编码山梨酮脱氢酶基因载体的氧化葡糖杆菌的用途、检测谷胱甘肽作用于氧化葡糖杆菌过程中细胞内蛋白质变化的方法、以及发酵用原料玉米浆的质量控制指标的方法。
Description
维生素 c二步混菌发酵的菌种改造和过程优化 技术领域
本发明属于工业微生物领域。 具体而言, 本发明涉及检测维 生素 C工业生产菌株传代过程中蛋白质、 磷脂组、 营养环境和小 分子代谢物变化的方法。 本发明还涉及提高维生素 C 的前体 2- 酮基 -L-古龙酸工业产量的方法, 包括混菌进化传代培养、 强化两 菌相互作用提高 2-酮基 -L-古龙酸产量的方法以及分子生物学基 因改造方法和添加谷胱甘肽的方法。 本发明还提供了用于发酵的 原料玉米浆的质量控制指标。 背景技术
随着经济发展和生活水平不断提高,人类对健康越来越重视, 各种维生素类保健品的需求量逐年增加。 在各种维生素中, 维生 素 C是一种高效抗氧化剂, 参与人体新陈代谢中重要的生物合成 过程, 是维持机体营养、 生长所必需的维生素。 它还在药品、 食 品和化妆品添加等方面有极为广泛的应用。
目前,我国生产维生素 C的方法为"二步发酵法",第一步发酵 使用黑醋杆菌将山椠醇转化为 L-山椠糖,第二步发酵为巨大芽孢杆 菌和氧化葡糖杆菌混合发酵, 将山椠糖转化为维生素 C的前体 2- 酮基 -L-古龙酸。其中,第二步发酵中,氧化葡糖杆菌( Gluconobacter oxydans )为产酸菌, 巨大芽抱軒菌 (Bacillus megaterium)为伴生菌, 若不加入巨大芽孢杆菌而单独使用氧化葡糖杆菌时, 生长极端緩 慢, 产酸效率低, 当加入巨大芽孢杆菌, 可使氧化葡糖杆菌生长速 率提高, 产酸量增加, 但是, 巨大芽孢杆菌 (Bacillus megaterium) 和氧化葡糖杆菌 ( Gluconobacter oxydans )混菌发酵 2-酮基 -L-古
龙酸的转化率尚有可提高的空间。
在两菌混合培养中, 它们之间的交流最先经由感受外界信号的 细胞膜, 再进一步传递到胞内, 并产生一系列的信号事件, 包括细 胞内蛋白质的变化、 细胞膜磷脂组的变化。 另外, 培养液的营养环 境不断的发生变化, 进而传递到胞内, 产生一系列不同的生长 酵行为。 对于这些变化的研究和测定, 将对揭示传代培养强化两菌 相互作用促进产酸的作用机制提供有利信息,并为进一步优化生产 工艺提供支持。
另一方面,提高氧化葡糖杆菌自身的糖酸转化能力是提高混菌 发酵生产效率的关键。分子生物学操作和代谢工程手段加快了菌株 人工进化、 能够快速提高菌株特性, 可以基于基因信息有目的地高 效改造菌株。 专利 CN1621518和专利 CN1515669获得了氧化葡糖 杆菌进行糖酸转化的关键酶——山椠酮脱氢酶的核酸序列。基于该 信息可以对氧化葡糖杆菌进行分子水平改造,进而提高其与巨大芽 孢杆菌混合发酵时的 2-酮基 -L-古龙酸混菌发酵性能。
此外, 添加谷胱甘肽后, 氧化葡糖杆菌体生长及 2-酮 -L-古龙 酸产量显著提高, 其作用机理尚不明确。 通过高通量的蛋白组学的 手段来了解添加谷胱甘肽进行氧化葡糖杆菌发酵过程中的蛋白质 变化规律, 可揭示谷胱甘肽促进氧化葡糖杆菌生长及 2-酮 -L-古龙 酸生产的作用机制,为对氧化葡糖杆菌进行分子生物学改造提供有 利信息, 从而提高其生长及生产能力。
另一方面, 发酵原料玉米浆对于发酵产品也有很大影响。 玉米 浆是生产玉米淀粉过程中在浸渍玉米时得到的副产品。它含有氨基 酸、 有机酸、 可溶性糖、 维生素和金属盐类等多种营养物质, 是生 产抗生素等培养基中的重要原料,为微生物生长提供天然的有机氮 源。 由于其价档^氐廉、 营养丰富, 在工业微生物发酵中得到广泛地
应用。 玉米浆现有的技术质量检测方法由各生产厂商自行规定, 并 无国家统一标准。 现行的质量检查规定外观浓稠、 不透明; 色泽棕 色到棕褐色; 无腐臭等异味; 及规定干重、 蛋白质、 酸度、 亚硫酸 和灰分的含量标准。 这些检查不能科学准确地判定原料的质量, 不 同批次的原料对发酵产品的效价有很大的影响,为了全面准确地控 制原料的质量, 保证高效价发酵产品, 提高产率, 避免浪费, 故有 必要对其质量控制指标进行研究。 发明内容
本发明的第一个方面提供了一种混菌进化传代培养提高 2-酮 基 -L-古龙酸产量的方法, 包括如下步骤:
( 1 ) 固体培养:
取存于液氮的 10-50(^L保藏于体积浓度为 15-30%的甘油水溶 液中的氧化葡糖杆菌 (Gluconobacter oxydans )和 10-500μ 保藏 于体积浓度为 15-30%的甘油水溶液中的巨大芽孢杆菌 (Bacillus megaterium)分别接种于固体培养基上, 28-35°C ,培养 24-48小时; ( 2 )种子培养:
将经步骤( 1 )培养的巨大芽孢杆菌和氧化葡糖杆菌分别转入 种子培养基, 在 28-35。C, 200-280 r/min摇床振荡培养, 24h-48h, 得到巨大芽孢杆菌种子液和氧化葡糖杆菌种子液;
将巨大芽孢杆菌和氧化葡糖杆菌接种到新的种子培养基中,使 巨大芽孢杆菌的密度为 2xl07-2xl010 cfu/ml ,使氧化葡糖杆菌的密 度为 2xl08-2xlOu cfu/ml, 在 28-35。C, 200-280 r/min摇床振荡培 养, 以 24h-48h为传代周期, 以体积比为 1%-10%为传代比接入新 的种子培养基中, 传代 50-80天;
( 3 )分纯:
将步骤(2 )获得的传代培养混菌菌株划线分纯, 再分别接种 于固体培养基上, 28-35eC培养 24-48小时;再分别转入种子培养基, 在 28-35。C, 200-280 r/min摇床振荡培养 24h-48h, 得到进化了的 巨大芽孢杆菌种子液和进化了的氧化葡糖杆菌种子液;
( 4 )发酵:
将所述原始巨大芽孢杆菌和进化了的氧化葡糖杆菌接种到发 酵培养基中, 使原始巨大芽孢杆菌的密度为
, 使进化了的氧化葡糖杆菌的密度为 2xl07-2xl09 cfu/ml,在 28-35。C, 200-280 r/min摇床振荡培养 72h-96h, 获得 2-酮基 -L-古龙酸。
固体培养基的制备为: 按比例称取 L-山椠糖 10-50g, 玉米浆 2-10g,牛肉骨 2-10g,酵母浸粉 2-10g, 尿素 0.5-5g,蛋白胨 2-12g, 琼脂 10-50g, KH2PO40.5-5g, MgSO40.1-0.7g, CaCO30.5-5g, 加水 至 1L, 调 pH为 6.5-7.0, 121。C灭菌 20min, 制成固体培养基。
固体培养基的制^ ¾选的是: 按比例称取 L-山椠糖 20g, 玉米 浆 3g, 牛肉骨 3g, 酵母浸粉 3g, 尿素 lg, 蛋白胨 10g, 琼脂 20g, KH2P04lg, MgSO40.2g, CaC03lg,加水至 1L,调 pH为 6.8, 121 °C 灭菌 20min, 制成固体培养基。
种子培养基制备为: 按比例称取 L-山椠糖 10-50g, 玉米浆 2-10g,牛肉骨 2-10g,酵母浸粉 2-10g, 尿素 0.5-5g,蛋白胨 2-12g, KH2PO40.5-5g, MgSO40.1-0.7g, CaCO30.5-5g, 加水至 1L, 调 pH 为 6.5-7.0, 121。C灭菌 20min, 制成种子培养基。
种子培养基的制备优选的是: 按比例称取 L-山椠糖 20g, 玉米 浆 3g,牛肉骨 3g,酵母浸粉 3g, 尿素 lg,蛋白胨 10g, KH2P04lg, MgSO40.2g, CaC03lg,加水至 1L,调 pH为 6.8, 121。C灭菌 20min, 制成种子培养基。
发酵培养基制备为: 按比例称取 L-山椠糖 40-120g, 玉米浆
10-50g,尿素 10-25g, KH2PO40.5-3g, MgSO40.2-1.2g, CaCO30.5-5g 加水至 1L,调 pH为 6.5 -7.5, 121。C灭菌 20min,制成发酵培养基。
发酵培养基的制备优选的是: 按比例称取 L-山椠糖 80g, 玉米 浆 20g, 尿素 12g, KH2P04lg, MgSO40.5g, CaC03lg, 加水至 1L, 调 pH为 7.0, 121。C灭菌 20min, 制成发酵培养基。
该方法通过混菌进化传代培养数十代后, 能明显提高巨大芽孢 軒菌 (Bacillus megaterium)和氧化葡糖軒菌 ( Gluconobacter oxydans )的生长速度和氧化葡糖杆菌 ( Gluconobacter oxydans ) 产 2-酮基 -L-古龙酸效率, 从而可提高对培养基的利用效率, 提高 L-山椠糖的转化效率 10%-15%。 本发明的第二个方面提供了强化两菌相互作用提高 2-酮基 -L- 古龙酸产量的方法, 包括如下步骤:
( 1 ) 固体培养:
取存于液氮的 10-50(^L保藏于体积浓度为 15-30%的甘油水溶 液中的氧化葡糖杆菌 (Gluconobacter oxydans )和 10-500μ 保藏 于体积浓度为 15-30%的甘油水溶液中的巨大芽孢杆菌 (Bacillus megaterium)分别接种于固体培养基上, 28-35°C ,培养 24-48小时; ( 2 )种子培养:
将经步骤( 1 )培养的巨大芽孢杆菌和氧化葡糖杆菌分别转入 种子培养基, 在 28-35。C, 200-280 r/min摇床振荡培养, 24h-48h, 得到巨大芽孢杆菌种子液和氧化葡糖杆菌种子液;
将巨大芽孢杆菌和氧化葡糖杆菌接种到新的种子培养基中,使 巨大芽孢杆菌的密度为 2xl07-2xl010 cfu/ml ,使氧化葡糖杆菌的密 度为 2xl08-2xlOu cfu/ml, 在 28-35。C, 200-280 r/min摇床振荡培 养, 以 24h-48h为传代周期, 以体积比为 1%-10%为传代比接入新
的种子培养基中, 传代 100-200天;
( 3 )分纯:
将步骤(2 )获得的传代培养混菌菌株划线分纯, 再分别接种 于固体培养基上, 28-35eC培养 24-48小时;再分别转入种子培养基, 在 28-35。C, 200-280 r/min摇床振荡培养 24h-48h, 得到进化了的 巨大芽孢杆菌种子液和进化了的氧化葡糖杆菌种子液;
( 4 )发酵:
将所述进化了的巨大芽孢杆菌和进化了的氧化葡糖杆菌接种 到发酵培养基中, 使进化了的巨大芽孢杆菌的密度为 2xl07-2xl010 cfu/ml , 使进化了的氧化葡糖杆菌的密度为 xloS xloUcfu/ml, 在 28-35。C, 200-280 r/min摇床振荡培养 72h-96h, 获得 2-酮基 -L- 古龙酸或将所述原始巨大芽孢杆菌和进化了的氧化葡糖杆菌接种 到发酵培养基中, 使原始巨大芽孢杆菌的密度为 2xl07-2><101() cfu/ml , 使进化了的氧化葡糖杆菌的密度为 2xl07-2xl09 cfu/ml, 在 28-35。C, 200-280 r/min摇床振荡培养 72h-96h, 获得 2-酮基 -L- 古龙酸。
固体培养基的制备为: 按比例称取 L-山椠糖 10-50g, 玉米浆 2-10g,牛肉骨 2-10g,酵母浸粉 2-10g, 尿素 0.5-5g,蛋白胨 2-12g, 琼脂 10-50g, KH2PO40.5-5g, MgSO40.1-0.7g, CaCO30.5-5g, 加水 至 1L, 调 pH为 6.5-7.0, 121。C灭菌 20min, 制成固体培养基。
固体培养基的制^ ¾选的是: 按比例称取 L-山椠糖 20g, 玉米 浆 3g, 牛肉骨 3g, 酵母浸粉 3g, 尿素 lg, 蛋白胨 10g, 琼脂 20g, KH2P04lg, MgSO40.2g, CaC03lg,加水至 1L,调 pH为 6.8, 121 °C 灭菌 20min, 制成固体培养基。
种子培养基制备为: 按比例称取 L-山椠糖 10-50g, 玉米浆 2-10g,牛肉骨 2-10g,酵母浸粉 2-10g, 尿素 0.5-5g,蛋白胨 2-12g,
KH2PO40.5-5g, MgSO40.1-0.7g, CaCO30.5-5g, 加水至 1L, 调 pH 为 6.5-7.0, 121。C灭菌 20min, 制成种子培养基。
种子培养基的制备优选的是: 按比例称取 L-山椠糖 20g, 玉米 浆 3g,牛肉骨 3g,酵母浸粉 3g, 尿素 lg,蛋白胨 10g, KH2P04lg, MgSO40.2g, CaC03lg,加水至 1L,调 pH为 6.8, 121。C灭菌 20min, 制成种子培养基。
发酵培养基制备为: 按比例称取 L-山椠糖 40-120g, 玉米浆 10-50g,尿素 10-25g, KH2PO40.5-3g, MgSO40.2-1.2g, CaCO30.5-5g 加水至 1L,调 pH为 6.5 -7.5, 121。C灭菌 20min,制成发酵培养基。
发酵培养基的制备优选的是: 按比例称取 L-山椠糖 80g, 玉米 浆 20g, 尿素 12g, KH2P04lg, MgSO40.5g, CaC03lg, 加水至 1L, 调 pH为 7.0, 121。C灭菌 20min, 制成发酵培养基。
该方法通过混菌进化传代培养数十代后, 能明显提高巨大芽孢 軒菌 (Bacillus megaterium)和氧化葡糖軒菌 ( Gluconobacter oxydans )的生长速度和氧化葡糖杆菌 ( Gluconobacter oxydans ) 产 2-酮基 -L-古龙酸效率, 从而可提高对培养基的利用效率, 提高 L-山椠糖的转化效率 10%-15%。 本发明的第三个方面提供了检测维生素 C 工业混菌传代不同 代数蛋白质变化的方法, 包括如下步骤:
( 1 )混菌传代培养:
①固体培养:
取存于液氮的 10-20(^L保藏于体积浓度为 15-30%的甘油水溶 液中的氧化葡糖杆菌 (Gluconobacter oxydans )和 10-200μ 保藏 于体积浓度为 15-30%的甘油水溶液中的巨大芽孢杆菌 (Bacillus megaterium)分别接种于固体培养基上, 28-35°C ,培养 24-48小时;
②种子培养:
将经步骤(1 )①培养的巨大芽孢杆菌和氧化葡糖杆菌分别转 入种子培养基, 在 28-35。C, 200-280 r/min摇床振荡培养 24h-48h, 得到巨大芽孢杆菌种子液和氧化葡糖杆菌种子液;
将巨大芽孢杆菌和氧化葡糖杆菌接种到新的种子培养基中,使 巨大芽孢杆菌的密度为 2xl07-2xl010 CFU/mL, 使氧化葡糖杆菌的 密度为 2xl08-2xlOn CFU/mL, 在 28-35。C, 200-280 r/min摇床振 荡培养, 以 24h-48h为传代周期, 以体积比为 1%-10%为传代比接 入新的种子培养基中,传代 100-150天,选定 3-4个取样时间取 3-4 个样;
③分纯:
将步骤(1 )②获得的 3-4个样的混菌细胞划线分纯, 再分别 接种于固体培养基上, 28-35。C培养 24 h-48 h; 再分别转入种子培 养基, 在 28_35。C, 200-280 rpm摇床振荡培养 24 h_48 h, 得到进 化了的巨大芽孢杆菌种子液和进化了的氧化葡糖杆菌种子液;保藏 于体积浓度为 15-30%的甘油水溶液中;
④不同进化时期巨大芽孢杆菌和氧化葡糖杆菌培养:
将步骤( 1 )③获得的进化了的巨大芽孢杆菌和进化了的氧化 葡糖杆菌分别接种到种子培养基中,使进化了的巨大芽孢杆菌的密 度为 2xl07-2xlOw CFU/mL , 进化了的氧化葡糖杆菌的密度为 2xl08-2xlOnCFU/mL, 在 28-35。C, 200-280 r/min摇床振荡培养 10-15h;
( 2 )细胞内蛋白质的测定:
①细胞收集及淬灭:
分别将步骤(1 )④获得的巨大芽孢杆菌培养物和氧化葡糖杆 菌培养物, 在 4。C下, 以 4000~6000rpm的转速离心, 收集下层的
细胞, 并用 pH为 7.2~7.4的磷酸盐緩冲液清洗, 用液氮淬灭, 终 止代谢反应; 用液氮研磨破碎细胞;
②提取细胞内蛋白:
取所述破碎细胞, 每份 80 - lOOmg 分别置于离心管中, 每管 加入 0.5~lmL细胞裂解液, 混匀, 冰上间歇超声破碎 20 ~ 50s; 加入 5 ~ 15μί质量比为 2 ~ 4:1的 DNase I /RNaseA酶混合溶液, 混匀, 4。C静置反应 10 ~ 30min; 加入 5 ~ 15μί 80 ~ 120mM的苯甲 基磺酰氣异丙醇溶液, 4。C静置 l~3h; 15000rpm离心 25~40min; 取上清, 得到蛋白溶液;
所述细胞裂解液为: 8 mol-L1尿素, 质量浓度为 4% 的 3-[(3 -胆酰胺丙基) -二乙胺】 -丙磺酸, 40 mM 的 Tris,余量为水;
③蛋白浓度测定:
采用 Bradford试剂盒, 将牛血清蛋白由低浓度到高浓度加入 考马斯亮蓝 G-250溶液中, 测定步骤(2)②获得的各个蛋白溶液 在 595nm处的吸光值, 建立标准曲线; 测定各个蛋白溶液蛋白的 浓度;
④沉淀蛋白
分别取含 50-100 μ§蛋白的步骤( 2 )②获得的各个蛋白溶液, 每份加入 4~6倍体积的 -20。C ~-40。C的丙酮, 在 -20。C ~-40。C的条 件下放置 12~20h; 离心, 弃上清, 沉淀用 -20。C~-40。C的体积浓 度为 70%-85%的丙酮水溶液洗涤; 干燥得到蛋白干粉;
⑤蛋白还原以及酶解
分别向各个蛋白干粉中, 添加 20~40μί 40~60mM的三乙^! 酸氢铵水溶液溶解蛋白; 再加入 l~4 L 三 (2-羧乙基)膦, 在 50~60。C还原反应 l-1.5h, 再加入 l~2 L甲基硫代磺酸甲酯, 室温 反应 10~15min, 终止还原反应; 再加入 20~30μί 浓度为
0.2~0.3 g/ L的胰蛋白酶水溶液, 37°C蛋白酶解 12~18小时, 得酶 解液;
⑥蛋白标记
向步骤(2 )⑤获得的各个酶解液中分别加入一管用 60~80μί 乙醇溶解的 iTRAQ标记试剂, 室温反应 l-1.5h;
⑦溶液混合
将步骤(2 )⑥标记后的各个来自巨大芽孢杆菌的蛋白溶液混 合; 将步骤(2 )⑥标记后的各个来自氧化葡糖杆菌的蛋白溶液混 合; 于 -40。C保存;
⑧差异表达蛋白鉴定
将(2 )⑦中得到的两组混合液, 进行 Q-Tof质傳鉴定, 得到蛋白谱, 通过定量得到各混合组样品的差异表达蛋白;
( 3 )聚类分析:
采用 Expande .O对步骤( 2 )⑧中得到的数据进行标准 化后, 进行 K-means 聚类, 得到具有不同变化^ 的数据类别, 获得候选差异蛋白;
( 4 )过程分析
将步骤(3 )获得的候选差异蛋白含量按照时间序列制成图表, 观察并分析这些蛋白变化的规律,进而发现混菌进化培养在提高氧 化葡糖杆菌产 2-酮 -L-古龙酸过程中的作用。
利用该方法可以从揭示混菌传代培养对巨大芽孢杆菌以及氧 化葡糖杆菌细胞内蛋白变化产生的影响,找到发酵过程中的重要蛋 白,这些蛋白含量的变化^ 为了解混菌发酵过程的内在机理提供 依据,从而为进一步优化发酵过程,提高维生素 C产量提供理论基 础。 同时也为工业混菌发酵过程的研究提供新的思路和方法。
本发明的第四个方面提供了分析维生素 C 生产菌株传代过程 磷脂组变化的方法, 包括如下步骤:
( 1 ) 固体培养:
取 10-500 保藏于体积浓度为 15-30%的甘油水溶液中的氧 化葡糖杆菌( Gluconobacter oxydans )和 10-500 μL保藏于体积浓 度为 15-30%的甘油水溶液中的 巨大芽孢杆菌 ( Bacillus megaterium )分别接种于固体培养基上, 28-35°C,培养 24 h_48 h;
( 2 )种子培养:
将经步骤( 1 )培养的巨大芽孢杆菌和氧化葡糖杆菌分别转入 种子培养基,在 28_35°C, 200-280 rpm摇床振荡培养, 24 h-48 h, 得到巨大芽孢杆菌种子液和氧化葡糖杆菌种子液;
将巨大芽孢杆菌和氧化葡糖杆菌接种到新的种子培养基中,使 巨大芽孢杆菌的密度为 2xl07-2xl010 cfu/mL,使氧化葡糖杆菌的密 度为 2xl08_2xlOu cfu/mL, 在 28_35°C, 200-280 rpm摇床振荡培 养, 以 24h-48h为传代周期, 以体积比为 1%-10%为传代比接入 新的种子培养基中, 传代 100-150天, 在 0-100或 0-150天选 3-5 个^ 时间取 3-5个样;
( 3 )分纯:
将步骤(2 )获得的 3-5个传代培养混菌菌株划线分纯, 再分 别接种于固体培养基上, 28-35°C培养 24 h-48 h;再分别转入种子 培养基, 在 28_35°C, 200-280 rpm摇床振荡培养 24 h_48 h, 得到 进化了的巨大芽孢杆菌种子液和进化了的氧化葡糖杆菌种子液;
( 4 )发酵:
将所述进化了的巨大芽孢杆菌、进化了的氧化葡糖杆菌以及混 合的进化了的巨大芽孢杆菌和进化了的氧化葡糖杆菌分别接种到 发酵培养基中, 使进化了的巨大芽孢杆菌的密度为 2χ107-2χ101β
cfu/mL ,使进化了的氧化葡糖杆菌的密度为 2X108-2X1011 cfu/mL, 在 28_35°C, 200-280 rpm摇床振荡培养 10 h-15 h;
( 5 )细胞磷脂组的提取:
①取在步骤(4 )摇床振荡培养 10 h-15 h 的三种细胞悬液 100-200 mL, 1000-3000 rpm离心 3-10 min, 去除上清液, 保留细 胞, 用 pH= 7.2-7.4的磷酸盐緩冲液洗细胞 1-3次,相同条件离心, 去除上清, 得到细胞;
②将步骤①所得细胞制成干粉, 称取 200-300 mg细胞干粉, 置于离心管 A中, 加入 0.5-0.8 mL超纯水, 充分混匀;
③向离心管 A中再加入 2-4 mL提取液,充分混匀; 1000-3000 rpm离心 3-10 min, 使溶液分层,取下层有机溶剂层, 置于离心管 B中;
④重复步骤③ 2-4次, 至细胞完全沉降;
⑤向离心管 B中,加入 0.8-1.2 mol/L KC1水溶液 0.5—1.5 mL, 充分混匀, 2000-4000 rpm离心 3-10 min, 除去含水溶性杂质的上 清;
⑥再向离心管 B加入 1-3 mL超纯水, 充分混匀, 2000-4000 rpm离心 3-10 min, 去上清;
⑦蒸馏或氮气吹干步骤⑥所得混合物中的有机溶剂,得到总磷 脂提取混合物;
⑧将所述总磷脂提取混合物溶于 0.2-2 mL储存液中制成样品, 冷冻 -40°C以下保存;
⑨检测前, 向所述样品内加入磷脂标准品, 使磷脂标准品终浓 度为 0.5—1.5 g/mL;
所述提取液是含有二丁基羟基甲苯的氯仿 /甲醇溶液,所述氯仿 /甲醇的体积比为 1-2:1, 所述二丁基羟基甲苯的质量分数为
0.005-0.01%;
所述储存液为含有二丁基羟基甲苯的氯仿 /甲醇溶液,所述氯仿 /甲醇的体积比为 1-4:1, 所述二丁基羟基甲苯的质量分数为 0.005-0.01%;
( 6 ) LC-MS检测
采用 LC-MS对步骤(5 )获得的加入了磷脂标准品的样品进 行检测,得到维生素 C生产菌株传代过程的磷脂组的分子结构和含 量数据;
( 7 )多元统计分析
将步骤(6 )获得的维生素 C生产菌株传代过程的磷脂组的分 子含量数据, 进行多元统计分析, 得到区分不同传代时间维生素 C 生产菌株的差异磷脂分子标志物;
( 8 )过程分析
将步骤(7 )获得的差异磷脂分子标志物的含量按照不同传代 时间制成图表, 观察并分析这些磚脂分子变化的规律, 进而发现在 混菌传代培养过程中起关键作用的磷脂分子及相关代谢途径,从而 为以提高 2-酮基 -L-古龙酸为目的的菌种改造和培养条件优化提供 方向。
所述细胞制成干粉的方法优选为使用液氮在研钵内研磨细胞。 所述步骤(5 )⑦中所述蒸馏优选为 30-40°C减压蒸馏。
所述磷脂标准品为磷脂酰甘油、磷脂酰乙醇胺、 溶血性磷脂酰 乙醇胺和磷脂酸至少两种。
所述磷脂酰甘油, 磷脂酰乙醇胺, 溶血性磷脂酰乙醇胺或磷脂 酸的脂肪酸疏水尾长度为每条 10-20个碳原子。
所述 LC-MS检测条件优选为:
色镨柱: Hypersil GOLD Silica, 其规格为 150mm x 2.1mm,
5μηι;
进样量: 10 μί;
柱温: 25 0C;
流动相 A ( % ): 氯仿( 89.5 ), 甲醇( 10 ), 氢氧化铵 ( 0.5 ); 流动相 B ( % ): 氯仿( 55 ), 甲醇( 39 ), 氢氧化铵 ( 0.5 ) , 水(5.5 );
梯度程序: 0-7 min, 20-30% B; 7-15 min 30-40% B; 15-20 min 40-50% B; 20—25 min 50% B ; 25-35min , 50-20% B; 35-45min, 20% B;
离子化方式: ESI (负离子方式) ;
扫描方式: MS Scan;
扫描范围: m/z 400-900;
扫描速度: 1000 scan/s;
毛细管电压: 3 KV;
锥孔电压: 30 V;
萃取电压 3 V;
离子源温度: 100°C;
脱溶剂气温度: 350°C;
锥孔气流量: 50 L/Hr
脱溶剂气流量: 400 L/Hr;
进 /出口能量: 50;
碰撞能量: 2;
HM1/LM1/HM2/LM2: 15.0;
Ion Energy 1: 1.0;
Ion Energy 2: 2.0。
所述多元统计分析方法为 Pareto预处理后进行主成分分析。
本发明提供了一种分析维生素 C 生产菌株传代过程磷脂组变 化的手段, 这种手段涉及细胞总磷脂的提取和分析, 多元统计方法 分析所获得的磷脂组学数据,通过对不同传代数的维生素 C生产菌 株在单独和混合培养条件下的磷脂分子分别进行定性和定量分析, 找到与增强维生素 C 生产菌株两菌相互作用相关的磷脂分子和代 谢途径的分析提供了方法, 对以提高 2-酮基 -L-古龙酸为目的的菌 种改造和培养条件优化具有重要的意义。 本发明的第五个方面提供了检测维生素 C 生产菌株传代过程 中营养环境变化的方法, 包括如下步骤:
( 1 )混菌传代培养:
①固体培养:
取存于液氮的 10-500 μL保藏于体积浓度为 15-30%的甘油水 溶液中的氧化葡糖杆菌( Gluconobacter oxydans )和 10-500 μL保 藏于体积浓度为 15-30%的甘油水溶液中的巨大芽孢杆菌 (Bacillus megaterium)分别接种于固体培养基上, 28-35°C , 培养 24-48 h;
②种子培养:
将经步骤(1 )①培养的巨大芽孢杆菌和氧化葡糖杆菌分别转 入种子培养基, 在 28-35。C, 200-280 r/min摇床振荡培养 24-48 h, 分别得到巨大芽孢杆菌种子液和氧化葡糖杆菌种子液;
将巨大芽孢杆菌和氧化葡糖杆菌接种到一个新的种子培养基 中, 使巨大芽孢杆菌的密度为 SxlO^xli^ CFU/mL, 使氧化葡糖 杆菌的密度为 2xl08-2xlOu CFU/mL, 在 28-35。C, 200-280 r/min 摇床振荡混菌培养, 以 24-48h为传代周期, 以体积比为 1%-10% 为传代比接入新的种子培养基中, 传代 100-150天得到混菌细胞, 在传代 0-100天或 0-150天中选定 3-4个时间取样, 取 3-4个样;
③分纯:
将步骤(1 )②获得的 3-4个样的混菌细胞划线分纯后再分别 接种于固体培养基上, 28-35。C培养 24-48 h; 再分别转入新的种子 培养基, 在 28_35。C, 200-280 rpm摇床振荡培养 24-48 h, 分别得 到巨大芽孢杆菌种子液和氧化葡糖杆菌种子液;保藏于体积浓度为 15-30%的甘油水溶液中;
④发酵:
将步骤(1 )③获得的巨大芽孢杆菌和氧化葡糖杆菌以及将两 种菌混合在一起的混合菌, 分别接种到新的种子培养基中, 使巨大 芽孢杆菌的密度为 2xl07-2xl010 CFU/mL, 氧化葡糖杆菌的密度为 2xl08-2xlOnCFU/mL, 在 28-35。C, 200-280 r/min摇床振荡培养 10-15 h;
( 2 )营养环境中物质的测定:
①培养液的收集:
分别取步骤(1 )④获得的巨大芽孢杆菌培养液、 氧化葡糖杆 菌培养液和混菌体系培养液 1-2 mL, 以 5000-10000 rpm的转速离 心, 收集上清, 并用 0.22 μπι纤维素微孔滤膜过滤, 得滤液;
②样品制备:
取步骤( 2 )®获得的滤液 10-50 置于离心管中,加入 50-200 μΐ,的 0.04-0.14 mg/ml氘标记的琥珀酸甲醇溶液为内标物, 冷冻干 燥; 加入 40-100 浓度为 20 mg/mL的甲氧基胺盐酸盐的吡啶溶 液于 30。C-40。C水浴中肟化反应 60-120 min; 再加入 50-100 LN- 甲基 -N-三甲基硅烷三氟乙酰胺于 35。C -40。C水浴进行硅烷化反应 30-60 min;
③ GC-TOFMS检测:
将 1 步骤( 2 )②获得的样品进到气相色 中, 色傳柱为
DB-5MS, 所述色镨柱的规格为 30 mx0.25 mm i.d., 进样口温度为 250。C-280。C,载气为高纯氦气,流速 0.6-0.8ml/min,分流比 3: 1-20: 1, 柱温箱升温程序为: 初始 50。C-80。C, 保持 2 min-5 min, 以 4°C/min-8。C/min的速度升到 260。C-300。C, 保持 3 min-8 min, 使 用 EI电离源, 源温 230°C-260°C, 检测器电压 2300 V-2700V, 电 离电压 60 eV-80 eV,电流 30 μΑ-50 μΑ;质傳检测范围 50-800 m/z; 营养环境物质的鉴定使用 NIST 2005数据库,质傳数据的处理和营 养环境物质相对含量的测定使用 Masslynx 4.1软件;并通过对色谱 峰面积积分处理, 并与内标物的峰面积对照, 得到营养环境物质的 相对含量;
( 3 )主成分分析:
①将步骤( 2 )获得的营养环境物质的相对含量的数据进 行 Pareto预处理;
②用 Metlab 7.0 ( Mathworks. Inc. )软件对步骤( 3 ) ® ^处 理后的数据进行主成分分析, 得到差异营养环境标志物;
( 4 )过程分析
将差异营养环境标志物的相对含量按照不同传代时间制成图 表,观察并分析这些物质变化的规律,检测出维生素 C生产菌株传 代过程中营养环境的变化。
利用该方法可以从揭示混菌传代培养对巨大芽孢杆菌、氧化葡 糖杆菌以及混菌体系产生的影响,找到影响传代培养营养环境中的 重要物质,这些物质含量的变化规律为了解传代培养促进氧化葡糖 杆菌生长及 2-酮基 -L-古龙酸生产的作用机理提供依据, 从而为进 一步优化发酵过程, 提高维生素 C产量提供理论基础。 本发明的第六个方面提供了一种分析检测维生素 C 生产菌株
传代培养过程中小分子代谢物变化的方法, 包括如下步骤:
( 1 )混菌传代培养:
①固体培养:
取保藏于体积浓度为 15-30%的甘油水溶液中的氧化葡糖杆菌 ( Gluconobacter oxydans )和保藏于体积浓度为 15-30%的甘油水 溶液中的巨大芽孢杆菌 (Bacillus megaterium)分别接种于固体培养 基上, 28-35 培养 24-48 h;
②种子培养:
将经步骤( 1 )①培养的巨大芽孢杆菌和氧化葡糖杆菌分别转 入种子培养基, 在 28-35 , 200-280 rpm摇床振荡培养 24-48 h, 分别得到巨大芽孢杆菌种子液和氧化葡糖杆菌种子液;
将巨大芽孢杆菌和氧化葡糖杆菌接种到一个新的种子培养基 中, 使巨大芽孢杆菌的密度为 SxlO^xli^ CFU/mL, 使氧化葡糖 杆菌的密度为 2xl08-2xlOu CFU/mL, 在 28-35*Ό, 200-280 rpm摇 床振荡培养, 以 24-48h为传代周期, 以体积比为 1%-10%为传代 比接入新的种子培养基中, 传代 100-150天得到混菌细胞, 在传代 0-100天或 0-150天中选定 3-5个时间^ , 取 3-5个样;
③分纯:
将步骤(1 )②获得的 3-5个样的混菌细胞划线分纯后再分别 接种于固体培养基上, 28-35 培养 24-48 h; 再分别转入新的种子 培养基, 在 28-35 , 200-280 rpm摇床振荡培养 24-48 h, 分别得 到进化了的巨大芽孢杆菌种子液和氧化葡糖杆菌种子液;保藏于体 积浓度为 15-30%的甘油水溶液中;
④发酵:
将步骤(1 ) ③获得的进化了的巨大芽孢杆菌和氧化葡糖杆菌 以及将两种菌混合在一起的混合菌, 分别接种到新的种子培养基
中, 使进化了的巨大芽孢杆菌的密度为 xlO^xli^ CFU/mL, 进 化了的氧化葡糖杆菌的密度为 2xl08-2xlOnCFU/mL, 在 28-35 , 200-280rpm摇床振荡培养 10-15 h;
( 2 )胞内小分子代谢物样品的制备和测定:
①各取在步骤( 1 )④获得的三种细胞悬液 100-200 mL, 分别 在 1000-3000 rpm 离心 3-10 min, 去除上清液, 保留细胞, 用 pH=7.2-7.4的磷酸盐緩冲液洗细胞 1-3次,相同^ ^离心,去除上 清, 得到细胞;
②将步骤( 2 )①所得细胞制成干粉, 各称取 30-60 mg细胞干 粉, 分别置于三个离心管中, 再加入 0.5-1.5 mL提取液, 加入 30-70μί浓度为 0.020-0.060mg/mL 氘标记的琥珀酸甲醇溶液为内 标物, 混匀; 1000-3000 rpm离心 3-10 min, 取上清液置于三个新 的离心管中冷冻干燥;
③将步骤(2 )②获得三个离心管中分别加入 40-100 浓度 为 10-30 mg/mL的甲氧基胺盐酸盐的吡啶溶液于 水浴中 "化反应 60-120 mill;再加入 50-100μί Ν-甲基 -Ν-三甲基硅烷三氟 乙酰胺于 35 -40 水浴进行硅烷化反应 30-60 min;
所述提取液为体积分数为 50-70%的甲醇水溶液;
④ GC-TOF/MS检测:
将 1 步骤( 2 )③获得的样品进到气相色 中, 色傳柱为 DB-5MS,所述色镨柱的¾ ^为 30 m 0.25 mm i.d.,进样口温度为 ISO -ISOX , 载气为高纯氦气, 恒压 80-100KPa, 分流比 3: 1-20: 1, 柱温箱升温程序为: 初始 δθ -δθ , 保持 3 min-6 min, 以 4*Ό /min-S /min的升到 όθ ^Οθ , 保持 3 min-8 min, 使用 EI电 离源, 源温 230*Ό-260<Ό, 检测器电压 2300 V-2700V, 电离电压 60 eV-80 eV, 电流 30 μΑ-50 μΑ; 质傳检测范围 50-800 m/z; 小分子
代谢物的鉴定使用 NIST 2005数据库,质谱数据的处理和代谢物相 对含量的测定使用 Masslynx 4.1软件;并通过对色傳峰面积积分处 理, 并与内标物的峰面积对照, 得到小分子代谢物的相对含量; ( 3 )主成分分析:
①将步骤(2 )④获得的维生素 C生产菌株传代过程的小分子 代谢物的相对含量数据进行 Pareto预处理;
②用 SIMCA-P 11.5软件对预处理后的数据进行主成分分析, 得到区分不同传代时间维生素 C生产菌株的小分子代谢物标志物;
( 4 )过程分析
将小分子代谢物标志物的含量按照不同传代时间制成图表,观 察并分析小分子代谢物标志物变化的规律,检测出维生素 C生产菌 株传代过程中细胞内小分子代谢物的变化。
所述细胞制成干粉的方法为液氮研磨细胞。 本发明的第七个方面提供了通过代谢工程的手段来改造氧化 葡糖杆菌, 增加其山椠酮脱氢酶基因的拷贝数, 提高氧化葡糖杆菌 与巨大芽孢杆菌混菌发酵转化 L-山椠糖为 2-酮基 -L-古龙酸的性能 的方法。 其包括如下步骤:
( 1 ) 山椠酮脱氢酶基因的体外扩增:
采用细菌基因组提取试剂盒提取氧化葡糖杆菌的基因组;取该 基因组溶液 1μ1, 5xFastPfu buffer 4μ1, 20mM的 dNTP 2μ1, 20ηΜ 的引物 1 0·4μ1, 20ηΜ的引物 2 0·4μ1, 无菌水 11.8μ1, FastPfu酶 0.4μ1, 在 PCR管中混合均匀; 将 PCR管;^ PCR仪中进行扩增 循环, 扩增程序为: 95。C 2min; 95 °C 20s, 55°C 35s, 72 °C 2min, 共 25个循环; 72。C 5min; 4。C 30min。 将 PCR产物进行琼脂糖凝 胶电泳,将 PCR产物条带切下,经琼脂糖凝胶回收试剂盒纯化 PCR
扩增产物。
所 述 引 物 1 的 序 列 为 : 5,- CCCAAGCTTGACTGGCAGCAGCGCAAC-3'
所 述 引 物 2 的 序 列 为 : 5,- CGCGGATCCCCGTGATAGCGGCACATGTC-3'
( 2 )编码山椠酮脱氢酶基因载体的构建:
取步骤(1 )获得的 PCR扩增产物溶液 8μ1, 与 Ιμΐ lOxdigest buffer, 0.5μ1 Hindlll酶, 0.5μ1 BamHI酶混合均匀, 在 37。C条件 下进行酶切反应 2小时; 反应后产物进行琼脂糖凝胶电泳, 将酶切 产物条带切下, 经琼脂糖凝胶回收试剂盒纯化酶切 PCR产物。 取 载体 pBBRlMCS溶液 8μ1,与 Ιμΐ lOxdigest buffer, 0.5μ1 ΚρηΙ酶, 0.5μ1 Hindlll酶混合均匀,在 37。C条件下进行酶切反应 2小时;反 应后产物进行琼脂糖凝胶电泳, 将酶切产物条带切下, 经琼脂糖凝 胶回收试剂盒纯化酶切载体产物。 取酶切 PCR产物 5.5μ1, 酶切载 体产物 3μ1, lOxligase buffer Ιμΐ, DNA ligase 0.5μ1, 混合均匀, 在 22。C条件下进行连接反应 30min。 将连接产物用化学转化法转化入 大肠杆菌 DH5a中, 涂布于含抗生素的 LB固体培养基上,在 37°C 条件下培养 I2h。 培养后获得的单菌落在 LB液体培养基中 37。C培 养 12h, 用质粒小量提取试剂盒提取质粒, 获得编码山椠酮脱氢酶 基因载体。
( 3 )编码山椠酮脱氢酶基因载体转化入氧化葡糖杆菌
将氧化葡糖杆菌涂布在固体培养基上, 在 30。C条件下培养 48 小时; 用 2ml无菌水将菌体洗下, 冰浴 10min, 4。C, 4000rpm离 心 5min后收集细胞, 用预冷的无菌水洗一次, 10%甘油洗两次后, ΙΟΟμΙ 10%甘油重悬细胞; 与步骤( 2 )所得编码山椠酮脱氢酶基因 载体的水溶液 ΙΟμΙ混合均匀置于电转杯中, 冰浴 5min, 将电转杯
置于电转仪中 1800V电击;电击产物与 900μ1种子培养基混合均匀, 在 30。C, 140^111 下培养 2小时, 将培养物涂布于固体培养基 上, 在 30。C条件下培养 4天, 获得的单菌落转入种子培养基中, 在 30°C , 250rpm条件下培养, 获得含有编码山椠酮脱氢酶基因载体 的氧化葡糖杆菌。
所述固体培养基为: L-山椠糖 20g, 玉米浆 3g, 牛肉骨 3g, 酵 母浸粉 3g, 尿素 lg,蛋白胨 10g,琼脂 20g,KH2PO4lg,MgSO40.2g, CaC03lg, 加水至 1L, 调 pH为 6.8, 121。C灭菌 20min。
所述种子培养基为: L-山椠糖 20g, 玉米浆 3g, 牛肉骨 3g, 酵 母浸粉 3g, 尿素 lg,蛋白胨 10g, KH2P04lg, MgSO40.2g, CaC03lg, 加水至 1L, 调 pH为 6.8, 121。C灭菌 20min。
( 4 )混菌发酵
将步骤(3 )获得的含有编码山椠酮脱氢酶基因载体的氧化葡 糖杆菌和巨大芽孢杆菌接种到发酵培养基中,使含有编码山椠酮脱 氢酶基因载体的氧化葡糖杆菌的密度为 4xl08cfu/ml , 使巨大芽孢 杆菌的密度为 4xl08 cfu/ml, 在 30。C, 250rpm条件下培养 120h, 获得 2-酮基 -L-古龙酸。
所述发酵培养基为: 按比例称取 L-山椠糖 80g, 玉米浆 20g, 尿素 12g, KH2P04lg, MgSO40.5g, CaC03lg, 加水至 1L, 调 pH为 7.0, 121。C灭菌 20min。
利用该方法能提高氧化葡糖杆菌和巨大芽孢杆菌混菌发酵转 化 L-山椠糖生产 2-酮基 -L-古龙酸的糖酸转化率。 本发明的第八个方面涉及检测谷胱甘肽提高氧化葡糖杆菌产 2-酮 -L-古龙酸过程中细胞内蛋白质变化的方法, 包括如下步骤: ( 1 )细胞内蛋白质的测定:
①细胞收集及淬灭:
取 3-5份氧化葡糖杆菌以 8%~16%的体积比分别接种到发酵培 养基 A中,另取 3-5份所述氧化葡糖杆菌以 8%~16%的体积比分别 接种到发酵培养基 B中, 将两种接种后的培养基在 28 C~32 C, 转 速为 200~250rpm的 下培养发酵,在发酵过程中选取 1 h、 15 h 为^ 1 点取出发酵液样品, 在 4。C下, 以 4000~6000rpm的转速离 心, 收集下层的细胞, 并用 pH为 7.2~7.4的磷酸盐緩冲液清洗, 用液氮淬灭, 终止代谢反应; 用液氮研磨破碎细胞, 获得 3-5份从 培养基 A中发酵 1 h收集淬灭的破碎细胞, 3-5份从培养基 A中发 酵 15 h收集淬灭的破碎细胞, 3-5份从培养基 B中发酵 lh收集淬 灭的破碎细胞, 3-5份从培养基 B中发酵 15h收集淬灭的破碎细 胞;
所 i L酵培养基 A为: 80 g-L 1 山椠糖, 20 g-L 1 玉米浆, 1 g*L 1 KH2P04, 0.2 g*L 1 MgS04,^ 12 g*L 1尿素, 余量为水;
所 i L酵培养基 B为: 80 g-L 1 山椠糖, 20 g-L 1 玉米浆, 1 g-L 1 KH2P04, 0.2 g-L 1 MgS04, and 12 g*L 1尿素, 0.8~1.5mg*mL 1 的谷胱甘肽, 余量为水;
②提取细胞内蛋白:
取步骤①获得的破碎细胞,每份 100 ~ 200mg分别置于离心管 中,每管加入 0.5 ~ 2ml细胞裂解液,混匀,冰上间 声破碎 20 ~ 50s;加入 5 ~ 15μί 的质量比为 2 ~ 4:1的 DNase I /RNaseA酶混合 溶液, 混匀, 4。C静置反应 10 ~ 30min; 加入 5 ~ 15μί 80 ~ 120mM 的苯甲基磺酰氣异丙醇溶液, 4。C静置 l ~ 3h; 15000rpm离心 25 ~ 40min; 取上清,得到蛋白溶液; 所述细胞裂解液为: 8 mol«L-l 尿 素, 质量浓度为 4% 的 (3-[(3 -胆酰胺丙基) -二乙胺】 -丙磺酸), 40 mM 的 Tris,余量为水;
③蛋白浓度测定:
采用 Bradford试剂盒, 将牛血清蛋白由低浓度到高浓度加入 考马斯亮蓝 G-250 溶液中, 测定步骤②获得的各个蛋白溶液在 595nm处的吸光值,建立标准曲线;测定各个蛋白溶液蛋白的浓度;
④沉淀蛋白
分别取包含 50-150 蛋白的步骤③获得的各个蛋白溶液, 加 入 4 ~ 6倍体积的 -20。C ~ -40。C的丙酮, 沉淀 12 ~ 20h; 离心, 弃上 清, 沉淀用 -20°C ~ -40°C的体积浓度为 70%-85%的丙酮水溶液洗 涤; 冷冻干燥备用; -80°C贮存;
⑤蛋白还原以及酶解
向步骤④所得的各个干燥蛋白中, 添加 10~40μί 40~60mM的 三乙 酸氢铵水溶液溶解蛋白;
加入 l~4 L 三(2-象乙基)膦, 在 50~60。C反应 lh, 对各个 蛋白进行还原化处理; 然后加入 l~2 L甲基硫代磺酸甲酯, 室温反 应 10~15min, 终止还原反应;
向上述溶液中, 加浓度为 0.2~0.3 g/ L 的胰蛋白酶水溶液 20~30μί, 37°C反应 12~18小时, 进行蛋白酶解;
⑥蛋白标记
在每个经步骤⑤酶解的蛋白酶解液中分别加入一管用 60~80μ 乙醇溶解的 iTRAQ标记试剂, 室温反应 lh;
⑦溶液混合
将步骤溶液⑥获得的溶液混合得 3-5份混合液, 使每个混合液 中都包括从培养基 A 中发酵 1 h 收集淬灭的破碎细胞再经步骤 ②-⑥后获得的标记蛋白、 从培养基 A中发酵 15 h收集淬灭的破碎 细胞再经步骤②-⑥后获得的标记蛋白、从培养基 B中发酵 1 h收集 淬灭的破碎细胞再经步骤② -⑥后获得的标记蛋白和从培养基 B 中
发酵 15 h收集淬灭的破碎细胞再经步骤②-⑥后获得的标记蛋白; 于 -20。C保存;
⑧差异表达蛋白鉴定
将⑦中得到的混合液,进行 Q-Tof质傳鉴定,得到蛋白谱, 通过定量得到各混合组样品的差异表达蛋白;
( 2 )主成分分析:
采用 matlab对步骤( 1 )⑧中得到的数据进行标准化后, 进行主成分分析, 得到具有不同变化规律的数据类别, 获得候选差 异蛋白;
( 3 )过程分析
将步骤(2 )获得的候选差异蛋白含量按照时间序列制成图表, 观察并分析这些蛋白变化的规律,进而发现谷胱甘肽在提高氧化葡 糖杆菌产 2-酮 -L-古龙酸过程中的作用。
利用该方法可以从揭示氧化葡糖杆菌受谷胱甘肽作用后细胞 内蛋白变化^ , 找到发酵过程中的重^^白, 这些蛋白含量的变 化^ 为了解发酵过程的内在机理提 据,从而为进一步优化发 酵过程,提高维生素 C产量,对氧化葡糖杆菌进行分子改造提供理 论基础。 同时也为工业混菌发酵过程的研究提供新的思路和方法。 本发明的第九个方面涉及寻找发酵用原料玉米浆的质量控制 指标的方法, 其特征是包括下述步骤:
( 1 ) 对玉米浆的化学成分的测定:
①样品的制备:
将 0.5-2g均匀的发酵用原料玉米浆置于离心管中, 离心收集上 清; 将获得的上清液用超纯水稀幹 10-40体积倍, 取 10-4(^L置于 另一离心管中, 加入 30-50μί的 0.040mg/mL氘标记的琥珀酸甲醇
溶液为内标; 冷冻干燥后,加入 50-100μί浓度为 20mg/mL的甲氧 基胺盐酸盐的吡啶溶液于 30。C-40。C水浴中肟化反应 60-120min;再 加入 60-100μίΝ-甲基 -N-三甲^ J 烷三氟乙酰胺于 35。C-40。C7j浴 进行硅烷化反应 20-50min;
②气相色谱 -飞行时间质谱联用仪测定方法:
将 Ιμΐ步骤①获得的样品进到气相色谱中,色谱柱为 DB-5MS, 所述色傳柱的规格为 30 mx0.25 mm i.d.,进样口温度 250。C-280。C, 载气为高纯氦气, 流速 0.6-0.8ml/min, 分流比 30: 1-10: 1, 柱温 箱升温程序为: 初始 50。C-80。C保持 2-5min, 以 4。C/min-8。C/min 的速度升到 250。C-300。C, 保持 8-10min, 使用 EI 电离源, 源温 230°C-280°C , 检测器电压 2300V-2700V, 电离电压 60eV-80eV, 电 流 30μΑ-50μΑ; 质傳检测范围 50-800m/z; 成分的鉴定使用 NIST 数据库, 质傳数据的处理和成分相对含量的测定使用 Masslynx 4.1 软件; 并通过对色傅峰面积积分处理, 并与内标物的峰面积对照, 得到发酵用原料玉米浆中化学成分的相对含量;
( 2 )偏最小二乘判别分析法
①将方法( 1 )获得的数据进行标准化和预处理;
②用 SIMCA-P 11.5软件对预处理后的数据进行偏最小二乘法 判别分析, 得到用于表达样^目似性和差异性的得分图、 载荷图和 VIP图; 在得分图中, 样品点相互之间距离越近, 说明样本的相似 度越大, 距离越远, 说明样本差异越大, 可用来寻找不同批次玉米 浆中各物质的相似和差异; 在载荷图中, 每个点表示每个物质, 距 离中心点距离越远的物质, 其在不同批次的含量差异越大, 便可作 为玉米浆的质量控制指标; VIP表示每个物质对区分样本的贡献大 小, VIP>1可以认为是对玉米浆质量影响最为显著的指标。
该方法采用高通量高分辨率的检测技术,可以同时测得玉米浆
中的多种化学成分, 方法简便, 经过多批原料验证, 重复性好。 该 方法分辨率和灵敏度高, 具有良好的重现性和稳定性, 采用的偏最 小二乘判别分析法可以迅速有效地从高通量数据中筛选到区别不 同批次原料的化学物质,发现玉米浆中九种化学物质葡萄糖、乳酸、 脯氨酸、 磷酸、 半乳糖、 丙氨酸、 果糖、 5-酮脯氨酸、 甘氛酸可以 考虑作为玉米浆的质量控制指标,是对现行玉米浆质量检查的一个 补充。 附图说明
图 1为根据本发明的第一个方面的传代过程中 2-酮基 -L-古龙 酸转化率变化。 图例: ♦: 2-酮基 -L-古龙酸转化率。
图 2为根据本发明的第一个方面的传代 50天后菌种发酵结果。 图 3为根据本发明的第二个方面的传代 100天后菌种交叉搭配 发酵结果。
图 4为根据本发明的第二个方面的传代 150天后菌种交叉搭配 发酵结果。
图 5为根据本发明的第三个方面的传代培养 0、 50、 100、 150 代的氧化葡糖杆菌蛋白聚类分析;
图 6为根据本发明的第三个方面的传代培养 0、 50、 100、 150 代的氧化葡糖杆菌细胞内山椠糖 /山椠酮脱氢酶相对表达量;
图 7为根据本发明的第三个方面的传代培养 0、 50、 100、 150 代的巨大芽孢杆菌蛋白聚类分析;
图 8为根据本发明的第三个方面的传代培养 0、 50、 100、 150 代的巨大芽孢杆菌聚类分析中类别 2。
图 9为根据本发明的第四个方面的不同传代时间的巨大芽孢杆 菌的磷脂含量变化;
图 10为根据本发明的第四个方面的不同传代时间的巨大芽孢 杆菌的主成分分析得分图 (图 10-1 )和荷载图 (图 10-2 );
图 11为根据本发明的第四个方面的不同传代时间的巨大芽孢 杆菌的磷脂分子标志物含量变化;
图 12为根据本发明的第四个方面的不同传代时间的氧化葡糖 杆菌的磷脂含量变化;
图 13为根据本发明的第四个方面的不同传代时间的氧化葡糖 杆菌的主成分分析得分图 (图 13-1 )和荷载图 (图 13-2 );
图 14为根据本发明的第四个方面的不同传代时间的氧化葡糖 杆菌的磷脂分子标志物含量变化;
图 15为根据本发明的第四个方面的不同传代时间的混菌的磷 脂含量变化;
图 16为根据本发明的第四个方面的不同传代时间的混菌的主 成分分析得分图 (图 16-1 )和荷载图 (图 16-2 );
图 17为根据本发明的第四个方面的不同传代时间的混菌的磷 脂分子标志物含量变化。
图 18为根据本发明的第五个方面的不同传代时间的氧化葡糖 杆菌营养环境的主成分分析得分图(图 18-1 )和载荷图(图 18-2 ) ;
图 19为根据本发明的第五个方面的不同传代时间的氧化葡糖 杆菌传代培养过程中营养环境标志物的变化图;
图 20为根据本发明的第五个方面的不同传代时间的巨大芽孢 杆菌营养环境物质的主成分分析得分图 (图 20-1 )和载荷图 (图 20-2 ) ;
图 21为根据本发明的第五个方面的不同传代时间的巨大芽孢 杆菌传代培养过程中营养环境标志物的变化图;
图 22为根据本发明的第五个方面的不同传代时间的混菌营养
环境物质的主成分分析得分图 (图 22-1 )和载荷图 (图 22-2 ) ; 图 23为根据本发明的第五个方面的不同传代时间的混菌传代 培养过程中营养环境中差异物质的变化图;
图 24为根据本发明的第六个方面的不同传代时间的氧化葡糖 杆菌小分子代谢物的主成分分析得分图 (图 24-1 )和载荷图 (图
24-2 ) ;
图 25为根据本发明的第六个方面的不同传代时间的氧化葡糖 杆菌传代培养过程中小分子代谢物标志物的含量变化;
图 26为根据本发明的第六个方面的不同传代时间的巨大芽孢 杆菌小分子代谢物的主成分分析得分图 (图 26-1 )和载荷图 (图 26-2 ) ;
图 27为根据本发明的第六个方面的不同传代时间的巨大芽孢 杆菌传代培养过程中小分子代谢物标志物的含量变化;
图 28为根据本发明的第六个方面的不同传代时间的混菌小分 子代谢物的主成分分析得分图 (图 28-1 )和载荷图 (图 28-2 ); 图 29为根据本发明的第六个方面的不同传代时间的混菌传代 培养过程中小分子代谢物标志物的含量变化;
图 30为根据本发明的第七个方面的含有编码山椠酮脱氢酶基 因载体的氧化葡糖杆菌和巨大芽孢杆菌混菌发酵结果;
图 31为根据本发明的第八个方面的对四组样品蛋白(混合溶液) 数据进行主成分分析: A、得分图: "▲,,表示来自培养基 B lh的样 品 /来自培养基 A lh的样品, "o"表示来自培养基 A 15h的样品 /来 自培养基 A lh的样品, "■,,表示来自培养基 B 15h的样品 /来自培 养基 A lh的样品; B、 物质载荷图
图 32为根据本发明的第八个方面的硫胺素转运蛋白及以其为 辅酶的重要酶表达情况: GSH-lh/KV-lh,表示来自培养基 B lh的
样品 /来自培养基 A lh的样品; KV-15h/KV-lh,表示来自培养基 A 15h的样品 /来自培养基 A lh的样品, GSH-15h/KV-lh, 表示来自 培养基 B 15h的样品 /来自培养基 A lh的样品;
图 33为根据本发明的第八个方面的三羧酸循环、 磷酸戊糖途 径中的关键酶表达情况: GSH-lh/KV-lh,表示来自培养基 B lh的 样品 /来自培养基 A lh的样品; KV-15h/KV-lh,表示来自培养基 A 15h的样品 /来自培养基 A lh的样品, GSH-15h/KV-lh, 表示来自 培养基 B 15h的样品 /来自培养基 A lh的样品;
图 34为根据本发明的第九个方面的不同批次玉米浆的偏最小 二乘法判别分析得分图, 图 34-1 为不同批次玉米浆主成分分析 t[l】-t[2】图; 图 34-2为不同批次玉米浆主成分分析 t[l】-u[l】图; 图 35为根据本发明的第九个方面的不同批次玉米浆的偏最小 二乘判别分析载荷图, 图 35-1为不同批次玉米浆 w*c[l卜 w*c[2】散 点图; 图 35-2为不同批次玉米浆第一主成分的 p-p(corr) S图; 图 36为根据本发明的第九个方面的不同批次玉米浆的偏最小 二乘判别分析 VIP图 ( VIP.>1 ) 。 具体实施方式
下面将结合实施例对本发明的实施方案进行详细描述。 本领 域技术人员将会理解, 下面的实施例仅用于说明本发明, 而不应 视为限定本发明的范围。 所用试剂或仪器未注明生产厂商者, 均 为可以通过市购获得的常规产品。 实施例 1-1
一种混菌进化传代培养提高 2-酮基 -L-古龙酸产量的方法,包括 如下步骤:
( 1 ) 固体培养:
固体培养基的制备为: 按比例称取 L-山椠糖 20g, 玉米浆 3g, 牛肉骨 3g,酵母浸粉 3g,尿素 lg,蛋白胨 10g,琼脂 20g, KH2P04lg, MgSO40.2 g, CaC03l g加水至 1L, 调 pH为 6.8, 121°C灭菌 20min, 制成固体培养基;
将存于液氮的 150μί保藏于体积浓度为 20%的甘油水溶液中的 氧化葡糖杆菌 ( Gluconobacter oxydans )和 150μί保藏于体积浓度 为 20%的甘油水溶液中的巨大芽孢杆菌 (Bacillus megaterium)分别 接种于固体培养基上, 30。C, 培养 48小时;
( 2 )种子培养:
种子培养基制备为: 按比例称取 L-山椠糖 20g, 玉米浆 3g, 牛 肉骨 3g,酵母浸粉 3g,尿素 lg,蛋白胨 10g, KH2P04lg, MgSO40.2 g, CaC03l g加水至 1L, 调 pH为 6.8, 121。C灭菌 20min, 制成种子 培养基;
将经步骤(1 )培养的巨大芽孢杆菌和氧化葡糖杆菌分别转入 种子培养基, 在 30。C, 250 r/min摇床振荡培养, 48h, 得到巨大芽 孢杆菌种子液和氧化葡糖杆菌种子液;
将巨大芽孢杆菌和氧化葡糖杆菌接种到新的种子培养基中,使 巨大芽孢杆菌的密度为 2xl07 cfu/ml , 使氧化葡糖杆菌的密度为 2xl09 cfu/ml,在 30。C, 250 r/min摇床振荡培养,以 24h为传代周期, 以体积比为 4%为传代比接入新的种子培养基中, 传代 50天;
( 3 )分纯:
将步骤(2 )获得的传代培养混菌菌株划线分纯, 再分别接种 于固体培养基上, 30°C , 培养 48小时; 再分别转入种子培养基, 在 30°C , 250 r/min摇床振荡培养 48h, 得到进化了的巨大芽孢杆菌种 子液和进化了的氧化葡糖杆菌种子液;
( 4 )发酵:
发酵培养基制备为: 按比例称取 L-山椠糖 80g, 玉米浆 20g, 尿 素 12g, KH2P04lg, MgSO40.5 g, CaC03lg,加水至 1L,调 pH 为 7.0, 121。C灭菌 20min, 制成发酵培养基;
( 4 )发酵:
将原始的巨大芽孢杆菌和进化了的氧化葡糖杆菌接种到发酵 培养基中, ^^始的巨大芽孢杆菌的密度为 2xl07 cfu/ml , 使进化 了的氧化葡糖杆菌的密度为 2xl09 cfu/ml, 在 30。C, 250 r/min摇床 振荡培养 96h, 获得 2-酮基 -L-古龙酸。
2-酮基 -L-古龙酸和 L-山椠糖含量测定:
采用高效液相色谱法( HPLC ) 。
样品制备: 取发酵培养不同时间的发酵液 lmL于 1.5mL离心管 中, 10000r/min转速离心 3min,取上清 ΙΟΟμ 于 1.5mL离心管中, 并 加入 900μΙ^^动相(5mM H2S04 )得到稀幹十倍的样品。 振荡混匀 后, 用 0.22μπι的纤维素微孔滤膜过滤样品, 得到待测样品。
高效液相色镨条件: 色镨柱: bio-rad HPX-87H,流动相: 5mM H2S04, 流速: 0.6mL/min, 柱温: 65。C, 示差检测器。
检测结果见图 2。
图例: ◊: 原始氧化葡糖杆菌和原始巨大芽孢杆菌搭配; △ : 传代 50天氧化葡糖杆菌和原始巨大芽孢杆菌搭配。
原始氧化葡糖杆菌与原始巨大芽孢杆菌利用实施例 1-1步骤
( 4 )的发酵条件进行搭配混菌发酵的 2-酮基 -L-古龙酸产率达到 78%;
传代培养 50天的氧化葡糖杆菌与原始巨大芽孢杆菌搭配混菌 发酵的 2-酮基 -L-古龙酸产率达到 88.2%, 有了 10.2 %的提高。
实施例 1-2
一种混菌进化传代培养提高 2-酮基 -L-古龙酸产量的方法,包括 如下步骤:
( 1 ) 固体培养:
取存于液氮的 ΙΟμΙ^保藏于体积浓度为 30%的甘油水溶液中的 氧化葡糖杆菌( Gluconobacter oxydans )和 ΙΟμί保藏于体积浓度为 30%的甘油水溶液中的巨大芽孢杆菌 (Bacillus megaterium)分别接 种于固体培养基上, 35°C , 培养 24小时;
( 2 )种子培养:
将经步骤(1 )培养的巨大芽孢杆菌和氧化葡糖杆菌分别转入 种子培养基, 在 35。C, 200 r/min摇床振荡培养 24h, 得到巨大芽孢 杆菌种子液和氧化葡糖杆菌种子液;
将巨大芽孢杆菌和氧化葡糖杆菌接种到新的种子培养基中,使 巨大芽孢杆菌的密度为 2xl07cfu/ml , 使氧化葡糖杆菌的密度为 2xl08 cfu/ml, 在 35。C, 200r/min摇床振荡培养, 以 24h为传代周期, 以体积比为 2%为传代比接入新的种子培养基中, 传代 60天;
( 3 )分纯:
将步骤(2 )获得的传代培养混菌菌株划线分纯, 再分别接种 于固体培养基上, 35 C培养 24小时; 再分别转入种子培养基, 在 35°C , 200 r/min摇床振荡培养 24h, 得到进化了的巨大芽孢杆菌种 子液和进化了的氧化葡糖杆菌种子液;
( 4 )发酵:
将原始的巨大芽孢杆菌和进化了的氧化葡糖杆菌接种到发酵 培养基中, ^^始的巨大芽孢杆菌的密度为 2xl07 cfu/ml , 使进化 了的氧化葡糖杆菌的密度为 2xl09 cfu/ml, 在 35。C, 200 r/min摇床 振荡培养 96h, 获得 2-酮基 -L-古龙酸。
本实施例所用的培养基:
固体培养基的制备为: 按比例称取 L-山椠糖 10g, 玉米浆 10g, 牛肉骨 5g,酵母浸粉 2g, 尿素 5g,蛋白胨 5g,琼脂 10g, KH2P045g, MgSO40.5g, CaCO30.5g,加水至 1L,调 pH为 6.5, 121°C灭菌 20min, 制成固体培养基。
种子培养基制备为: 按比例称取 L-山椠糖 10g, 玉米浆 10g, 牛 肉骨 8g,酵母浸粉 2g, 尿素 5g,蛋白胨 2g, KH2P045g, MgSO40.5g, CaCO30.5g, 加水至 1L, 调 pH为 6.5, 121。C灭菌 20min, 制成种子 培养基。
发酵培养基制备为: 按比例称取 L-山椠糖 40g, 玉米浆 50g, 尿 素 20g, KH2PO40.5g, MgS041.2g, CaC032g加水至 1L, 调 pH为 6.5, 121。C灭菌 20min, 制成发酵培养基。
实施例 1-3
一种混菌进化传代培养提高 2-酮基 -L-古龙酸产量的方法,包括 如下步骤:
( 1 ) 固体培养:
取存于液氮的 200μί保藏于体积浓度为 15%的甘油水溶液中的 氧化葡糖杆菌 ( Gluconobacter oxydans )和 200μί保藏于体积浓度 为 15%的甘油水溶液中的巨大芽孢杆菌 (Bacillus megaterium)分别 接种于固体培养基上, 30°C , 培养 36小时;
( 2 )种子培养:
将经步骤(1 )培养的巨大芽孢杆菌和氧化葡糖杆菌分别转入 种子培养基, 在 30。C, 240 r/min摇床振荡培养 36h, 得到巨大芽孢 杆菌种子液和氧化葡糖杆菌种子液;
将巨大芽孢杆菌和氧化葡糖杆菌接种到新的种子培养基中,使 巨大芽孢杆菌的密度为 2xl08 cfu/ml , 使氧化葡糖杆菌的密度为 2xlOn cfu/ml, 在 30。C, 240 r/min摇床振荡培养, 以 36h为传代周
期, 以体积比为 1%为传代比接入新的种子培养基中, 传代 70天;
( 3 )分纯:
将步骤(2 )获得的传代培养混菌菌株划线分纯, 再分别接种 于固体培养基上, 30。C培养 36小时; 再分别转入种子培养基, 在 30°C , 240 r/min摇床振荡培养 36h, 得到进化了的巨大芽孢杆菌种 子液和进化了的氧化葡糖杆菌种子液;
( 4 )发酵:
将原始的巨大芽孢杆菌和进化了的氧化葡糖杆菌接种到发酵 培养基中, ^^始的巨大芽孢杆菌的密度为 2xl08cfu/ml , 使进化 了的氧化葡糖杆菌的密度为 2xlOu cfu/ml, 在 30。C, 240 r/min摇床 振荡培养 96h, 获得 2-酮基 -L-古龙酸。
本实施例所用的各个培养基:
固体培养基的制备为: 按比例称取 L-山椠糖 30g, 玉米浆 2g, 牛肉骨 10g, 酵母浸粉 5g, 尿素 0.5g, 蛋白胨 12g, 琼脂 30g, KH2PO40.5g, MgSO40.7g, CaC033g,加水至 1L,调 pH为 6.8, 121。C 灭菌 20min, 制成固体培养基。
种子培养基制备为: 按比例称取 L-山椠糖 30g, 玉米浆 2g, 牛 肉骨 10g, 酵母浸粉 8g, 尿素 0.5g, 蛋白胨 8g, KH2PO40.5g, MgSO40.7g, CaC033g, 加水至 1L, 调 pH为 6.8, 121。C灭菌 20min, 制成种子培养基。
发酵培养基制备为: 按比例称取 L-山椠糖 80g, 玉米浆 10g, 尿 素 25g, KH2P04lg, MgSO40.2g, CaC035g加水至 1L, 调 pH 为 6.8, 121。C灭菌 20min, 制成发酵培养基。
实施例 1-4
一种混菌进化传代培养提高 2-酮基 -L-古龙酸产量的方法,包括 如下步骤:
( 1 ) 固体培养:
取存于液氮的 500μί保藏于体积浓度为 20%的甘油水溶液中的 氧化葡糖杆菌 ( Gluconobacter oxydans )和 500μί保藏于体积浓度 为 20%的甘油水溶液中的巨大芽孢杆菌 (Bacillus megaterium)分别 接种于固体培养基上, 28。C, 培养 48小时;
( 2 )种子培养:
将经步骤(1 )培养的巨大芽孢杆菌和氧化葡糖杆菌分别转入 种子培养基, 在 28。C, 280 r/min摇床振荡培养 48h, 得到巨大芽孢 杆菌种子液和氧化葡糖杆菌种子液;
将巨大芽孢杆菌和氧化葡糖杆菌接种到新的种子培养基中,使 巨大芽孢杆菌的密度为 2xlOie cfu/ml , 使氧化葡糖杆菌的密度为 2xlOn cfu/ml, 在 28。C, 280 r/min摇床振荡培养, 以 48h为传代周 期, 以体积比为 10%为传代比接入新的种子培养基中, 传代 80天;
( 3 )分纯:
将步骤(2 )获得的传代培养混菌菌株划线分纯, 再分别接种 于固体培养基上, 28。C培养 48小时; 再分别转入种子培养基, 在 28 °C, 280 r/min摇床振荡培养 48h,得到进化了的巨大芽孢杆菌种 子液和进化了的氧化葡糖杆菌种子液;
( 4 )发酵:
将原始的巨大芽孢杆菌和进化了的氧化葡糖杆菌接种到发酵 培养基中, ^^始的巨大芽孢杆菌的密度为
, 使进化 了的氧化葡糖杆菌的密度为 2xlOu cfu/ml, 在 28。C, 280 r/min摇床 振荡培养 72h, 获得 2-酮基 -L-古龙酸。
本实施例所用的各个培养基:
固体培养基的制备为: 按比例称取 L-山椠糖 50g, 玉米浆 5g, 牛肉骨 2g,酵母浸粉 10g, 尿素 3g,蛋白胨 2g,琼脂 50g, KH2P043g,
MgSO40.1g, CaC035g, 加水至 1L, 调 pH为 7.0, 121。C灭菌 20min, 制成固体培养基。
种子培养基制备为: 按比例称取 L-山椠糖 50g, 玉米浆 8g, 牛 肉骨 2g, 酵母浸粉 10g, 尿素 3g, 蛋白胨 12g, KH2P043g, MgSO40.1g,CaCO30.5-5g,加水至 1L,调 pH为 7.0,121。C灭菌 20min, 制成种子培养基。
发酵培养基制备为: 按比例称取 L-山椠糖 120g, 玉米浆 30g, 尿素 10g, KH2P043g, MgSO40.5g, CaCO30.5g加水至 1L,调 pH 为 7.5, 121。C灭菌 20min, 制成发酵培养基。 实施例 2-1
一种强化两菌相互作用提高 2-酮基 -L-古龙酸产量的方法,包括 如下步骤:
( 1 ) 固体培养:
固体培养基的制备为: 按比例称取 L-山椠糖 20g, 玉米浆 3g, 牛肉骨 3g,酵母浸粉 3g,尿素 lg,蛋白胨 10g,琼脂 20g, KH2P04lg, MgSO40.2 g, CaC03l g加水至 1L, 调 pH为 6.8, 121°C灭菌 20min, 制成固体培养基;
将存于液氮的 150μί保藏于体积浓度为 20%的甘油水溶液中的 氧化葡糖杆菌 ( Gluconobacter oxydans )和 150μί保藏于体积浓度 为 20%的甘油水溶液中的巨大芽孢杆菌 (Bacillus megaterium)分别 接种于固体培养基上, 30。C, 培养 48小时;
( 2 )种子培养:
种子培养基制备为: 按比例称取 L-山椠糖 20g, 玉米浆 3g, 牛 肉骨 3g,酵母浸粉 3g,尿素 lg,蛋白胨 10g, KH2P04lg, MgSO40.2 g, CaC03l g加水至 1L, 调 pH为 6.8, 121。C灭菌 20min, 制成种子
培养基;
将经步骤(1 )培养的巨大芽孢杆菌和氧化葡糖杆菌分别转入 种子培养基, 在 30。C, 250 r/min摇床振荡培养, 48h, 得到巨大芽 孢杆菌种子液和氧化葡糖杆菌种子液;
将巨大芽孢杆菌和氧化葡糖杆菌接种到新的种子培养基中,使 巨大芽孢杆菌的密度为 2xl07 cfu/ml , 使氧化葡糖杆菌的密度为 2xl09 cfu/ml,在 30。C, 250 r/min摇床振荡培养,以 24h为传代周期, 以体积比为 4%为传代比接入新的种子培养基中, 传代 100天;
( 3 )分纯:
将步骤(2 )获得的传代培养混菌菌株划线分纯, 再分别接种 于固体培养基上, 30°C , 培养 48小时; 再分别转入种子培养基, 在 30°C , 250 r/min摇床振荡培养 48h, 得到进化了的巨大芽孢杆菌种 子液和进化了的氧化葡糖杆菌种子液;
( 4 )发酵:
发酵培养基制备为: 按比例称取 L-山椠糖 80g, 玉米浆 20g, 尿 素 12g, KH2P04lg, MgSO40.5 g, CaC03lg,加水至 1L,调 pH 为 7.0, 121。C灭菌 20min, 制成发酵培养基;
将进化了的巨大芽孢杆菌和进化了的氧化葡糖杆菌接种到发 酵培养基中, 使进化了的巨大芽孢杆菌的密度为 2xl07 cfu/ml , 使 进化了的氧化葡糖杆菌的密度为 2xl09 cfu/ml, 在 30。C, 250 r/min 摇床振荡培养 96h, 获得 2-酮基 -L-古龙酸。
实施例 2-2
一种强化两菌相互作用提高 2-酮基 -L-古龙酸产量的方法,包括 如下步骤:
步骤(1 ) 、 ( 2 )和(3 ) 同实施例 2-1
( 4 )发酵:
将原始的巨大芽孢杆菌和进化了的氧化葡糖杆菌接种到发酵 培养基中, ^^始的巨大芽孢杆菌的密度为 2xl07 cfu/ml , 使进化 了的氧化葡糖杆菌的密度为 2xl09 cfu/ml, 在 30。C, 250 r/min摇床 振荡培养 96h, 获得 2-酮基 -L-古龙酸。
2-酮基 -L-古龙酸和 L-山椠糖含量测定:
采用高效液相色谱法( HPLC ) 。
样品制备: 取发酵培养不同时间的发酵液 lmL于 1.5mL离心管 中, 10000r/min转速离心 3min,取上清 ΙΟΟμ 于 1.5mL离心管中, 并 加入 900μΙ^^动相(5mM H2S04 )得到稀幹十倍的样品。 振荡混匀 后, 用 0.22μπι的纤维素微孔滤膜过滤样品, 得到待测样品。
高效液相色镨条件: 色镨柱: bio-rad HPX-87H,流动相: 5mM H2S04, 流速: 0.6mL/min, 柱温: 65。C, 示差检测器。
实施例 2-1、 2-2检测结果见图 3。
图例: ◊: 原始氧化葡糖杆菌和原始巨大芽孢杆菌搭配; □: 传代 100天氧化葡糖杆菌和传代 100天巨大芽孢杆菌搭配; △: 传代 100天氧化葡糖杆菌和原始巨大芽孢杆菌搭配; 原始氧化葡糖杆菌与原始巨大芽孢杆菌利用实施例 2-1步骤 ( 4 )的发酵条件进行搭配混菌发酵的 2-酮基 -L-古龙酸产率达到 78%; 用实施例 2-1的方法传代培养 100天的进化了的氧化葡糖杆菌 和传代培养 100天的进化了的巨大芽孢杆菌搭配混菌发酵的 2-酮基 -L-古龙酸产率达到 91%-92%, 它比原始氧化葡糖杆菌与原始巨大 芽孢杆菌搭配混菌发酵的 2-酮基 -L-古龙酸产率提高了 13 % -14 %; 传代培养 100天的氧化葡糖杆菌与原始巨大芽孢杆菌搭配的混 菌发酵(实施例 2-2 )发酵周期和 2-酮基 -L-古龙酸转化率与传代培 养 100天的氧化葡糖杆菌和传代培养 100天的巨大芽孢杆菌混菌发 酵相似。
实施例 2-3
一种强化两菌相互作用提高 2-酮基 -L-古龙酸产量的方法,包括 如下步骤:
( 1 ) 固体培养:
取存于液氮的 ΙΟμΙ^保藏于体积浓度为 30%的甘油水溶液中的 氧化葡糖杆菌( Gluconobacter oxydans )和 ΙΟμί保藏于体积浓度为 30%的甘油水溶液中的巨大芽孢杆菌 (Bacillus megaterium)分别接 种于固体培养基上, 35°C , 培养 24小时;
( 2 )种子培养:
将经步骤(1 )培养的巨大芽孢杆菌和氧化葡糖杆菌分别转入 种子培养基, 在 35。C, 200 r/min摇床振荡培养 24h, 得到巨大芽孢 杆菌种子液和氧化葡糖杆菌种子液;
将巨大芽孢杆菌和氧化葡糖杆菌接种到新的种子培养基中,使 巨大芽孢杆菌的密度为 2xl07cfu/ml , 使氧化葡糖杆菌的密度为 2xl08 cfu/ml, 在 35。C, 200r/min摇床振荡培养, 以 24h为传代周期, 以体积比为 2%为传代比接入新的种子培养基中, 传代 150天;
( 3 )分纯:
将步骤(2 )获得的传代培养混菌菌株划线分纯, 再分别接种 于固体培养基上, 35 C培养 24小时; 再分别转入种子培养基, 在 35°C , 200 r/min摇床振荡培养 24h, 得到进化了的巨大芽孢杆菌种 子液和进化了的氧化葡糖杆菌种子液;
( 4 )发酵:
将所述进化了的巨大芽孢杆菌和进化了的氧化葡糖杆菌接种 到发酵培养基中,使进化了的巨大芽孢杆菌的密度为 2xl07cfu/ml , 使进化了的氧化葡糖杆菌的密度为 2xl08cfu/ml, 在 35。C, 200r/min 摇床振荡培养 96h, 获得 2-酮基 -L-古龙酸。
本实施例所用的培养基:
固体培养基的制备为: 按比例称取 L-山椠糖 10g, 玉米浆 10g, 牛肉骨 5g,酵母浸粉 2g, 尿素 5g,蛋白胨 5g,琼脂 10g, KH2P045g, MgSO40.5g, CaCO30.5g,加水至 1L,调 pH为 6.5, 121°C灭菌 20min, 制成固体培养基。
种子培养基制备为: 按比例称取 L-山椠糖 10g, 玉米浆 10g, 牛 肉骨 8g,酵母浸粉 2g, 尿素 5g,蛋白胨 2g, KH2P045g, MgSO40.5g, CaCO30.5g, 加水至 1L, 调 pH为 6.5, 121。C灭菌 20min, 制成种子 培养基。
发酵培养基制备为: 按比例称取 L-山椠糖 40g, 玉米浆 50g, 尿 素 20g, KH2PO40.5g, MgS041.2g, CaC032g加水至 1L, 调 pH为 6.5, 121。C灭菌 20min, 制成发酵培养基。
实施例 2-4
一种强化两菌相互作用提高 2-酮基 -L-古龙酸产量的方法,包括 如下步骤:
步骤(1 ) 、 ( 2 )和(3 ) 同实施例 2-3
( 4 )发酵:
将原始的巨大芽孢杆菌和进化了的氧化葡糖杆菌接种到发酵 培养基中, ^^始的巨大芽孢杆菌的密度为 2xl07 cfu/ml , 使进化 了的氧化葡糖杆菌的密度为 2xl09 cfu/ml, 在 35。C, 200 r/min摇床 振荡培养 96h, 获得 2-酮基 -L-古龙酸。
各个培养基同实施例 2-2。
实施例 2-3、 2-4检测结果见图 4。
图例: ◊: 原始氧化葡糖杆菌和原始巨大芽孢杆菌搭配; 口: 传代 150天氧化葡糖杆菌和传代 150天巨大芽孢杆菌搭配; △: 传代 150天氧化葡糖杆菌和原始巨大芽孢杆菌搭配; o: 原始氧化葡糖杆
菌和传代 150天巨大芽孢杆菌搭配。
原始氧化葡糖杆菌与原始巨大芽孢杆菌利用实施例 2-3步骤 ( 4 )的发酵条件进行搭配混菌发酵的 2-酮基 -L-古龙酸产率达到 78%; 用实施例 2-3的方法传代培养 150天的进化了的氧化葡糖杆菌 和传代培养 150天的进化了的巨大芽孢杆菌混菌发酵的 2-酮基 -L-古 龙酸产率在发酵末期达到 95%, 比原始氧化葡糖杆菌和原始巨大芽 孢杆菌混菌发酵的 2-酮基 -L-古龙酸产率混菌提高了 17 %,发酵周期 较原始混菌的发酵周期缩短了 9 % ;传代培养 150天的氧化葡糖杆菌 和原始巨大芽孢杆菌搭配的混菌体系发酵过程(实施例 2-4 )的 2- 酮基 -L-古龙酸转化率比原始混菌提高了 16 %, 发酵周期与传代培 养 150天的混菌相似。
实施例 2-5
一种强化两菌相互作用提高 2-酮基 -L-古龙酸产量的方法,包括 如下步骤:
( 1 ) 固体培养:
取存于液氮的 200μί保藏于体积浓度为 15%的甘油水溶液中的 氧化葡糖杆菌 ( Gluconobacter oxydans )和 200μί保藏于体积浓度 为 15%的甘油水溶液中的巨大芽孢杆菌 (Bacillus megaterium)分别 接种于固体培养基上, 30°C , 培养 36小时;
( 2 )种子培养:
将经步骤(1 )培养的巨大芽孢杆菌和氧化葡糖杆菌分别转入 种子培养基, 在 30。C, 240 r/min摇床振荡培养 36h, 得到巨大芽孢 杆菌种子液和氧化葡糖杆菌种子液;
将巨大芽孢杆菌和氧化葡糖杆菌接种到新的种子培养基中,使 巨大芽孢杆菌的密度为 2xl08 cfu/ml , 使氧化葡糖杆菌的密度为 2xlOn cfu/ml, 在 30。C, 240 r/min摇床振荡培养, 以 36h为传代周
期, 以体积比为 1%为传代比接入新的种子培养基中, 传代 200天;
( 3 )分纯:
将步骤(2 )获得的传代培养混菌菌株划线分纯, 再分别接种 于固体培养基上, 30。C培养 36小时; 再分别转入种子培养基, 在 30°C , 240 r/min摇床振荡培养 36h, 得到进化了的巨大芽孢杆菌种 子液和进化了的氧化葡糖杆菌种子液;
( 4 )发酵:
将所述进化了的巨大芽孢杆菌和进化了的氧化葡糖杆菌接种 到发酵培养基中, 使进化了的巨大芽孢杆菌的密度为 2xl08 cfu/ml ,使进化了的氧化葡糖杆菌的密度为 ZxloUcfu/ml, 在 30。C, 240 r/min摇床振荡培养 96h, 获得 2-酮基 -L-古龙酸。
本实施例所用的各个培养基:
固体培养基的制备为: 按比例称取 L-山椠糖 30g, 玉米浆 2g, 牛肉骨 10g, 酵母浸粉 5g, 尿素 0.5g, 蛋白胨 12g, 琼脂 30g, KH2PO40.5g, MgSO40.7g, CaC033g,加水至 1L,调 pH为 6.8, 121。C 灭菌 20min, 制成固体培养基。
种子培养基制备为: 按比例称取 L-山椠糖 30g, 玉米浆 2g, 牛 肉骨 10g, 酵母浸粉 8g, 尿素 0.5g, 蛋白胨 8g, KH2PO40.5g, MgSO40.7g, CaC033g, 加水至 1L, 调 pH为 6.8, 121。C灭菌 20min, 制成种子培养基。
发酵培养基制备为: 按比例称取 L-山椠糖 80g, 玉米浆 10g, 尿 素 25g, KH2P04lg, MgSO40.2g, CaC035g加水至 1L, 调 pH 为 6.8, 121。C灭菌 20min, 制成发酵培养基。
实施例 2-6
一种强化两菌相互作用提高 2-酮基 -L-古龙酸产量的方法,包括 如下步骤:
( 1 ) 固体培养:
取存于液氮的 500μί保藏于体积浓度为 20%的甘油水溶液中的 氧化葡糖杆菌 ( Gluconobacter oxydans )和 500μί保藏于体积浓度 为 20%的甘油水溶液中的巨大芽孢杆菌 (Bacillus megaterium)分别 接种于固体培养基上, 28。C, 培养 48小时;
( 2 )种子培养:
将经步骤(1 )培养的巨大芽孢杆菌和氧化葡糖杆菌分别转入 种子培养基, 在 28。C, 280 r/min摇床振荡培养 48h, 得到巨大芽孢 杆菌种子液和氧化葡糖杆菌种子液;
将巨大芽孢杆菌和氧化葡糖杆菌接种到新的种子培养基中,使 巨大芽孢杆菌的密度为 2xlOie cfu/ml , 使氧化葡糖杆菌的密度为 2xlOn cfu/ml, 在 28。C, 280 r/min摇床振荡培养, 以 48h为传代周 期, 以体积比为 10%为传代比接入新的种子培养基中, 传代 180天;
( 3 )分纯:
将步骤(2 )获得的传代培养混菌菌株划线分纯, 再分别接种 于固体培养基上, 28。C培养 48小时; 再分别转入种子培养基, 在 28 °C, 280 r/min摇床振荡培养 48h,得到进化了的巨大芽孢杆菌种 子液和进化了的氧化葡糖杆菌种子液;
( 4 )发酵:
将所述进化了的巨大芽孢杆菌和进化了的氧化葡糖杆菌接种 到发酵培养基中, 使进化了的巨大芽孢杆菌的密度为
2xl010cfu/ml , 使进化了的氧化葡糖杆菌的密度为 2xlOucfu/ml, 在 28。C, 280 r/min摇床振荡培养 72hh, 获得 2-酮基 -L-古龙酸。
本实施例所用的各个培养基:
固体培养基的制备为: 按比例称取 L-山椠糖 50g, 玉米浆 5g, 牛肉骨 2g,酵母浸粉 10g, 尿素 3g,蛋白胨 2g,琼脂 50g, KH2P043g,
MgSO40.1g, CaC035g, 加水至 1L, 调 pH为 7.0, 121。C灭菌 20min, 制成固体培养基。
种子培养基制备为: 按比例称取 L-山椠糖 50g, 玉米浆 8g, 牛 肉骨 2g, 酵母浸粉 10g, 尿素 3g, 蛋白胨 12g, KH2P043g, MgSO40.1g,CaCO30.5-5g,加水至 1L,调 pH为 7.0,121。C灭菌 20min, 制成种子培养基。
发酵培养基制备为: 按比例称取 L-山椠糖 120g, 玉米浆 30g, 尿素 10g, KH2P043g, MgSO40.5g, CaCO30.5g加水至 1L,调 pH 为 7.5, 121。C灭菌 20min, 制成发酵培养基。 实施例 3-1
一种检测维生素 C工业混菌传代不同代数蛋白质变化的方法, 包括如下步骤:
( 1 )混菌传代培养:
①固体培养:
于液氮的 20μί保藏于体积浓度为 15%的甘油水溶液中的 氧化葡糖杆菌( Gluconobacter oxydans )和 20μί保藏于体积浓度为 15%的甘油水溶液中的巨大芽孢杆菌 (Bacillus megaterium)分别接 种于固体培养基上, 28°C , 培养 24小时;
②种子培养:
将经步骤(1 )①培养的巨大芽孢杆菌和氧化葡糖杆菌分别转 入种子培养基, 在 28。C, 200r/min摇床振荡培养 24h, 得到巨大芽 孢杆菌种子液和氧化葡糖杆菌种子液;
将巨大芽孢杆菌和氧化葡糖杆菌接种到新的种子培养基中,使 巨大芽孢杆菌的密度为 2xl07 CFU/mL, 使氧化葡糖杆菌的密度为 2xl08 CFU/mL, 在 28。C, 200 r/min摇床振荡培养, 以 24h为传代周
期, 以体积比为 1%为传代比接入新的种子培养基中, 传代 150天, 选定 4个取样时间取 4个样, 分别为 0天、 50天、 100天、 150天;
③分纯:
将步骤( 1 )②获得的 4个样的混菌细胞划线分纯, 再分别接种 于固体培养基上, 28。C培养 24 h; 再分别转入种子培养基,在 28。C, 200 rpm摇床振荡培养 24 h, 得到进化了的巨大芽孢杆菌种子液和 进化了的氧化葡糖杆菌种子液;保藏于体积浓度为 15%的甘油水溶 液中;
④不同进化时期巨大芽孢杆菌和氧化葡糖杆菌培养:
将步骤( 1 )③获得的进化了的巨大芽孢杆菌和进化了的氧化 葡糖杆菌分别接种到种子培养基中,使进化了的巨大芽孢杆菌的密 度为 2xl07 CFU/mL , 进化了的氧化葡糖杆菌的密度为
2xl08CFU/mL, 在 28。C, 200 r/min摇床振荡培养 10h;
( 2 )细胞内蛋白质的测定:
①细胞收集及淬灭:
分别将步骤( 1 )④获得的巨大芽孢杆菌培养物和氧化葡糖杆 菌培养物, 在 4。C下, 以 4000rpm的转速离心, 收集下层的细胞, 并用 pH为 7.2的磷酸盐緩冲液清洗, 用液氮淬灭, 终止代谢反应; 用液氮研磨破碎细胞;
②提取细胞内蛋白:
取所述破碎细胞, 每份 80mg分别置于离心管中, 每管加入 0.5mL细胞裂解液, 混匀, 冰上间 声破碎 20s; 加入 5 L质量 比为 2:1的 DNase I /RNaseA酶混合溶液,混匀, 4。C静置反应 lOmin; 加入 5 L 80mM的苯甲基磺酰氟异丙醇溶液, 4。C静置 lh; 15000rpm 离心 25min; 取上清, 得到蛋白溶液;
所述细胞裂解液为: 8 mol-L 1尿素, 质量浓度为 4% 的 3-[(3
-胆酰胺丙基) -二乙胺】 -丙磺酸, 40 mM 的 Tris,余量为水;
③蛋白浓度测定:
采用 Bradford试剂盒,将牛血清蛋白由低浓度到高浓 入考 马斯亮蓝 G-250溶液中, 测定步骤(2 )②获得的各个蛋白溶液在 595nm处的吸光值,建立标准曲线;测定各个蛋白溶液蛋白的浓度;
④沉淀蛋白
分别取含 50 蛋白的步骤(2 )②获得的各个蛋白溶液, 每份 加入 4倍体积的 -20。C的丙酮, 在 -20。C的条件下放置 12h; 离心, 弃 上清, 沉淀用 -20。C的体积浓度为 70%的丙酮水溶液洗涤; 干燥得 到蛋白干粉;
⑤蛋白还原以及酶解
分别向各个蛋白干粉中,添加 20μ 40mM的三乙^!酸氢铵水 溶液溶解蛋白;再加入 l L 三(2-羧乙基)膦,在 50。C还原反应 lh, 再加入 l L甲基硫代磺酸甲酯, 室温反应 10min, 终止还原反应; 再加入 20μί浓度为 0.2 g/ L的胰蛋白酶水溶液, 37。C蛋白酶解 12小 时, 得酶解液;
⑥蛋白标记
向步骤(2 )⑤获得的各个酶解液中分别加入一管用 60μΙ乙醇 溶解的 iTRAQ标记试剂, 室温反应 lh;
⑦溶液混合
将步骤(2 )⑥标记后的各个来自巨大芽孢杆菌的蛋白溶液混 合; 将步骤(2 )⑥标记后的各个来自氧化葡糖杆菌的蛋白溶液混 合; 于 -40。C保存;
⑧差异表达蛋白鉴定
将(2 )⑦中得到的两组混合液, 进行 Q-Tof质谱鉴定, 得 到蛋白谱, 通过定量得到各混合组样品的差异表达蛋白;
( 3 )聚类分析:
采用 Expande .O对步骤(2 )⑧中得到的数据进行标准 化后, 进行 K-means聚类, 得到具有不同变化规律的数据类别, 获 得候选差异蛋白;
( 4 )过程分析
将步骤(3 )获得的候选差异蛋白含量按照时间序列制成图表, 观察并分析这些蛋白变化的规律,进而发现混菌进化培养在提高氧 化葡糖杆菌产 2-酮 -L-古龙酸过程中的作用。
在混菌传代培养过程, 氧化葡糖杆菌产生了多种进化方向, 表 现为细胞内蛋白在不同代数呈现不同表达规律, 见图 5。 通过聚类 分析, 发现它们的表达量变化可以分为 6类, 其中, 类别 1、 类别 3 以及类别 5表现为各代蛋白表达变化不大; 类别 2与类别 4表现为进 化后蛋白表 不同程度提高,其中包括负责转化山椠糖为 2-酮 -L- 古龙酸的山椠糖 /山椠酮脱氢酶。此酶在^代的表达情况如图 6所示, 在 50代有轻微的表达下调, 在 100代和 150代有逐渐提高的表达量。 此现象的原因, 可能为 50代时, 混菌之间发生剧烈的相互作用, 进 行适应性选择, 随着相互配合作用的增强, 氧化葡糖杆菌越来越适 应混菌环境, 具有了更强的生产能力。
同时, 对不同传代时期的巨大芽孢杆菌进行聚类分析, 结果如 图 7所示。 类别 1中 131种蛋白表达量无明显变化; 类别 2中 9种蛋白 表达量随着传代数增加呈现上调趋势; 类别 3中 88种蛋白表达量随 着传代数增加有微弱上调趋势; 类别 4中 25种蛋白在 50代有轻度下 调, 而后在 100代、 150代轻度上调。 此四类中, 变化最明显的为类 别 2, 具体蛋白表达情况, 如图 8所示。 在类别 2的 9个蛋白中, 4个 与 immune inhibitor A(immune inhibitor A; immune inhibitor A metalloprotease; immune inhibitor A precursor; peptide M6
immune inhibitor A)有关, 一个与寡狀转运有关 (oligopeptide bingding protein oppA), 此外还有抵抗活性氧的过氧化物歧化酶 (superoxide dismutase, Mn)。 Immune inhibitor A为芽抱軒菌中降 解抗菌肽的蛋白,对芽孢杆菌抵抗外部免疫系统有重要作用,此外, 它还是芽孢杆菌孢外壁的重要组成部分。其表达量随传代培养代数 增加,呈现上调,表明巨大芽孢杆菌芽孢的抗逆性有了提高。 同时, 转运寡肽能力也有所提高, 利于自身的生长需要。
综上所述,混菌传代培养对氧化葡糖杆菌以及巨大芽孢杆 菌均产生了利于默方生长的影响,表现为氧化葡糖杆菌生产能力的 提高, 以及巨大芽孢杆菌抗逆性的提高。 这一发现, 为后续对氧化 葡糖杆菌进行基因改造提供了依据,也为工业混菌过程研究及控制 提供了 J^?。
实施例 3-2
一种检测维生素 C工业混菌传代不同代数蛋白质变化的方法, 包括如下步骤:
( 1 )混菌传代培养:
①固体培养:
于液氮的 ΙΟμΙ^保藏于体积浓度为 20%的甘油水溶液中的 氧化葡糖杆菌( Gluconobacter oxydans )和 ΙΟμί保藏于体积浓度为 20%的甘油水溶液中的巨大芽孢杆菌 (Bacillus megaterium)分别接 种于固体培养基上, 30°C , 培养 36小时;
②种子培养:
将经步骤(1 )①培养的巨大芽孢杆菌和氧化葡糖杆菌分别转 入种子培养基, 在 30。C, 250 r/min摇床振荡培养 36h, 得到巨大芽 孢杆菌种子液和氧化葡糖杆菌种子液;
将巨大芽孢杆菌和氧化葡糖杆菌接种到新的种子培养基中,使
巨大芽孢杆菌的密度为 2xl08 CFU/mL, 使氧化葡糖杆菌的密度为 2xl09 CFU/mL, 在 30。C, 250r/min摇床振荡培养, 以 36h为传代周 期, 以体积比为 5%为传代比接入新的种子培养基中, 传代 100天, 选定 3个取样时间取 3个样, 分别为 0天、 50天、 100天;
③分纯:
将步骤( 1 )②获得的 3个样的混菌细胞划线分纯, 再分别接种 于固体培养基上, 30。C培养 36h; 再分别转入种子培养基, 在 30。C, 250 rpm摇床振荡培养 36 h, 得到进化了的巨大芽孢杆菌种子液和 进化了的氧化葡糖杆菌种子液;保藏于体积浓度为 20%的甘油水溶 液中;
④不同进化时期巨大芽孢杆菌和氧化葡糖杆菌培养:
将步骤( 1 )③获得的进化了的巨大芽孢杆菌和进化了的氧化 葡糖杆菌分别接种到种子培养基中,使进化了的巨大芽孢杆菌的密 度为 2xl08 CFU/mL , 进化了的氧化葡糖杆菌的密度为
2xl09CFU/mL, 在 30。C, 250 r/min摇床振荡培养 12h;
( 2 )细胞内蛋白质的测定:
①细胞收集及淬灭:
分别将步骤( 1 )④获得的巨大芽孢杆菌培养物和氧化葡糖杆 菌培养物, 在 4。C下, 以 5000rpm的转速离心, 收集下层的细胞, 并用 pH为 7.3的磷酸盐緩冲液清洗, 用液氮淬灭, 终止代谢反应; 用液氮研磨破碎细胞;
②提取细胞内蛋白:
取所述破碎细胞, 每份 90mg分别置于离心管中, 每管加入 0.8mL细胞裂解液, 混匀, 冰上间 声破碎 40s; 加入 ΙΟμΙ^质量 比为 3:1的 DNase I /RNaseA酶混合溶液,混匀, 4。C静置反应 20min; 加入 lO L lOOmM的苯甲基磺酰氣异丙醇溶液, 4。C静置 2h;
15000rpm离心 30min; 取上清, 得到蛋白溶液;
所述细胞裂解液为: 8 mol-L 1尿素, 质量浓度为 4% 的 3-[(3 -胆酰胺丙基) -二乙胺】 -丙磺酸, 40 mM 的 Tris,余量为水;
③蛋白浓度测定:
采用 Bradford试剂盒,将牛血清蛋白由低浓度到高浓 入考 马斯亮蓝 G-250溶液中, 测定步骤(2 )②获得的各个蛋白溶液在 595nm处的吸光值,建立标准曲线;测定各个蛋白溶液蛋白的浓度;
④沉淀蛋白
分别取含 80 蛋白的步骤(2 )②获得的各个蛋白溶液, 每份 加入 5倍体积的 -40。C的丙酮, 在 -40。C的条件下放置 15h; 离心, 弃 上清, 沉淀用 -40。C的体积浓度为 80%的丙酮水溶液洗涤; 干燥得 到蛋白干粉;
⑤蛋白还原以及酶解
分别向各个蛋白干粉中,添加 20μ 50mM的三乙^!酸氢铵水 溶液溶解蛋白;再加入 2 L 三( 2-羧乙基)膦,在 55。C还原反应 1.2h, 再加入 l L甲基硫代磺酸甲酯, 室温反应 10min, 终止还原反应; 再加入 25μί浓度为 0.25μδ/μί的胰蛋白酶水溶液, 37。C蛋白酶解 16 小时, 得酶解液;
⑥蛋白标记
向步骤(2 )⑤获得的各个酶解液中分别加入一管用 70μΙ乙醇 溶解的 iTRAQ标记试剂, 室温反应 1.2h;
⑦溶液混合
将步骤(2 )⑥标记后的各个来自巨大芽孢杆菌的蛋白溶液混 合; 将步骤(2 )⑥标记后的各个来自氧化葡糖杆菌的蛋白溶液混 合; 于 -40。C保存;
⑧差异表达蛋白鉴定
将(2 )⑦中得到的两组混合液, 进行 Q-Tof质谱鉴定, 得 到蛋白谱, 通过定量得到各混合组样品的差异表达蛋白;
( 3 )聚类分析:
采用 Expande .O对步骤(2 )⑧中得到的数据进行标准 化后, 进行 K-means聚类, 得到具有不同变化规律的数据类别, 获 得候选差异蛋白;
( 4 )过程分析
将步骤(3 )获得的候选差异蛋白含量按照时间序列制成图表, 观察并分析这些蛋白变化的规律,进而发现混菌进化培养在提高氧 化葡糖杆菌产 2-酮 -L-古龙酸过程中的作用。
实施例 3-3
一种检测维生素 C工业混菌传代不同代数蛋白质变化的方法, 包括如下步骤:
( 1 )混菌传代培养:
①固体培养:
取存于液氮的 200μί保藏于体积浓度为 30%的甘油水溶液中的 氧化葡糖杆菌 ( Gluconobacter oxydans )和 200μί保藏于体积浓度 为 30%的甘油水溶液中的巨大芽孢杆菌 (Bacillus megaterium)分别 接种于固体培养基上, 35。C, 培养 48小时;
②种子培养:
将经步骤(1 )①培养的巨大芽孢杆菌和氧化葡糖杆菌分别转 入种子培养基, 在 35。C, 280 r/min摇床振荡培养 48h, 得到巨大芽 孢杆菌种子液和氧化葡糖杆菌种子液;
将巨大芽孢杆菌和氧化葡糖杆菌接种到新的种子培养基中,使 巨大芽孢杆菌的密度为 2xl01G CFU/mL, 使氧化葡糖杆菌的密度为 2xlOn CFU/mL, 在 35。C, 280 r/min摇床振荡培养, 以 48h为传代
周期, 以体积比为 10%为传代比接入新的种子培养基中, 传代 150 天, 选定 4个取样时间取 4个样, 分别为 0天、 50天、 100天、 150天;
③分纯:
将步骤( 1 )②获得的 4个样的混菌细胞划线分纯, 再分别接种 于固体培养基上, 35。C培养 48 h; 再分别转入种子培养基,在 35。C, 280 rpm摇床振荡培养 48 h, 得到进化了的巨大芽孢杆菌种子液和 进化了的氧化葡糖杆菌种子液;保藏于体积浓度为 30%的甘油水溶 液中;
④不同进化时期巨大芽孢杆菌和氧化葡糖杆菌培养:
将步骤( 1 )③获得的进化了的巨大芽孢杆菌和进化了的氧化 葡糖杆菌分别接种到种子培养基中,使进化了的巨大芽孢杆菌的密 度为 2xlOie CFU/mL , 进化了的氧化葡糖杆菌的密度为
2xlOnCFU/mL, 在 35。C, 280 r/min摇床振荡培养 15h;
( 2 )细胞内蛋白质的测定:
①细胞收集及淬灭:
分别将步骤(1 )④获得的巨大芽孢杆菌培养物和氧化葡糖杆 菌培养物, 在 4。C下, 以 6000rpm的转速离心, 收集下层的细胞, 并用 pH为 7.4的磷酸盐緩冲液清洗, 用液氮淬灭, 终止代谢反应; 用液氮研磨破碎细胞;
②提取细胞内蛋白:
取所述破碎细胞, 每份 lOOmg分别置于离心管中, 每管加入 ImL细胞裂解液, 混匀, 冰上间 声破碎 50s; 加入 15 L质量比 为 4:1的 DNase l /RNaseA酶混合溶液, 混匀, 4。C静置反应 30min; 加入 15 L 120mM的苯甲基磺酰氣异丙醇溶液, 4。C静置 3h;
15000rpm离心 40min; 取上清, 得到蛋白溶液;
所述细胞裂解液为: 8 mol-L 1尿素, 质量浓度为 4% 的 3-[(3
-胆酰胺丙基) -二乙胺】 -丙磺酸, 40 mM 的 Tris,余量为水;
③蛋白浓度测定:
采用 Bradford试剂盒,将牛血清蛋白由低浓度到高浓 入考 马斯亮蓝 G-250溶液中, 测定步骤(2 )②获得的各个蛋白溶液在 595nm处的吸光值,建立标准曲线;测定各个蛋白溶液蛋白的浓度;
④沉淀蛋白
分别取含 100 蛋白的步骤(2 )②获得的各个蛋白溶液, 每 份加入 6倍体积的 -40。C的丙酮, 在 -40。C的^^下放置 20h; 离心, 弃上清, 沉淀用 -40。C的体积浓度为 85%的丙酮水溶液洗涤; 干燥 得到蛋白干粉;
⑤蛋白还原以及酶解
分别向各个蛋白干粉中,添加 40μ 60mM的三乙^!酸氢铵水 溶液溶解蛋白;再加入 4 L 三( 2-羧乙基)膦,在 60。C还原反应 1.5h, 再加入 2jiL甲基硫代磺酸甲酯, 室温反应 15min, 终止还原反应; 再加入 30μί浓度为 0.3 g/ L的胰蛋白酶水溶液, 37。C蛋白酶解 18小 时, 得酶解液;
⑥蛋白标记
向步骤(2 )⑤获得的各个酶解液中分别加入一管用 8(^L乙醇 溶解的 iTRAQ标记试剂, 室温反应 1.5h;
⑦溶液混合
将步骤(2 )⑥标记后的各个来自巨大芽孢杆菌的蛋白溶液混 合; 将步骤(2 )⑥标记后的各个来自氧化葡糖杆菌的蛋白溶液混 合; 于 -40。C保存;
⑧差异表达蛋白鉴定
将(2 )⑦中得到的两组混合液, 进行 Q-Tof质谱鉴定, 得 到蛋白谱, 通过定量得到各混合组样品的差异表达蛋白;
( 3 )聚类分析:
采用 Expande .O对步骤(2 )⑧中得到的数据进行标准 化后, 进行 K-means聚类, 得到具有不同变化规律的数据类别, 获 得候选差异蛋白;
( 4 )过程分析
将步骤(3 )获得的候选差异蛋白含量按照时间序列制成图表, 观察并分析这些蛋白变化的规律,进而发现混菌进化培养在提高氧 化葡糖杆菌产 2-酮 -L-古龙酸过程中的作用。
实验证明, 实施例 3-2和实施例 3-3与实施例 3-1的结果类似。 本发明所采用的固体培养基、种子培养基的组成选自中国专利 申请号为 201110314740.9公开的培养基, 例如:
固体培养基:按比例称取 L-山椠糖 20 g,玉米浆 3 g,牛肉骨 3 g, 酵母浸粉 3 g, 尿素 1 g,蛋白胨 10 g,琼脂 20 g, KH2P04 1 g, MgS04 0.2 g, CaC03 1 g, 加水至 1 L, 调 pH=6.8, 1210C灭菌 20 min, 制 成固体培养基。
种子培养基:按比例称取 L-山椠糖 20 g,玉米浆 3 g,牛肉骨 3 g, 酵母浸粉 3 g, 尿素 l g, 蛋白膝 10 g, KH2P04 1 g, MgS04 0.2 g, CaC03 l g, 加水至 1 L, 调 pH=6.8, 121。C灭菌 20 min, 制成种子 培养基。 实施例 4-1
一种分析维生素 C生产菌株传代过程磷脂组变化的方法, 其特 征是包括如下步骤:
( 1 ) 固体培养:
取 ΙΟΟμί保藏于体积浓度为 20%的甘油水溶液中的氧化葡糖杆 菌 ( Gluconobacter oxydans )和 ΙΟΟμί保藏于体积浓度为 20%的甘
油水溶液中的巨大芽孢杆菌 (Bacillus megaterium)分别接种于固体 培养基上, 30°C, 培养 36小时;
( 2 )种子培养:
将经步骤(1 )培养的巨大芽孢杆菌和氧化葡糖杆菌分别转入 种子培养基, 在 30°C, 240 rpm摇床振荡培养, 36h, 得到巨大芽孢 杆菌种子液和氧化葡糖杆菌种子液;
将巨大芽孢杆菌和氧化葡糖杆菌接种到新的种子培养基中,使 巨大芽孢杆菌的密度为 2xl08 cfu/mL , 使氧化葡糖杆菌的密度为 2xl010cfu/mL,在 30°C, 240 rpm摇床振荡培养,以 36h为传代周期, 以体积比为 5%为传代比接入新的种子培养基中, 传代 150天, 分别 在第 0天、 第 50天、 第 100天和第 150天取 4个样;
( 3 )分纯:
将步骤(2 )获得的 4个传代培养混菌菌株划线分纯, 再分别接 种于固体培养基上, 30°C培养 36小时; 再分别转入种子培养基, 在 30°C, 240 rpm摇床振荡培养 36h,得到进化了的巨大芽孢杆菌种子 液和进化了的氧化葡糖杆菌种子液;
( 4 )发酵:
将进化了的巨大芽孢杆菌、进化了的氧化葡糖杆菌以及混合的 进化了的巨大芽孢杆菌和进化了的氧化葡糖杆菌分别接种到发酵 培养基中,使进化了的巨大芽孢杆菌的密度为 2xl08 cfu/mL ,使进 化了的氧化葡糖杆菌的密度为
在 30°C, 240 rpm摇 床振荡培养 13h;
( 5 )细胞磷脂组的提取:
①取在步碌( 4 床振荡培养 13 h的三种细胞悬液 150mL, 2000 rpm离心 5 min, 去除上清液, 保留细胞, 用 pH=7.3的磷酸盐緩冲 液洗细胞 2次, 相同^ ^离心, 去除上清, 得到细胞;
②将步骤①所得三种细胞使用液氮在研钵内分别研磨制成干 粉, 每种称取 250 mg细胞干粉, 置于三支离心管 A中, 分别加入 0.6mL超纯水, 充分混匀;
③向三支离心管 A中分别再加入 3 mL提取液, 充分混匀; 2000 rpm离心 5 min, 使溶液分层, 取下层有机溶剂层, 置于三支离心管 B中;
④重复步碌③ 3次, 至三种细胞完全沉降;
⑤向三支离心管 B中, 各加入 1.0 mol/L KCl7j溶液 1.0 mL, 充 分混匀, 3000 111离心5 111111, 除去含水溶性杂质的上清;
⑥再向三支离心管 B各加入 2 mL超纯水, 充分混匀, 3000 rpm 离心 5 min, 去上清;
⑦ 30°C减压蒸馏步骤⑥所得混合物中的有机溶剂,得到三种总 磷脂提取混合物;
⑧将三种总磷脂提取混合物溶于 1 mL储存液中制成样品,冷冻 _40°C以下保存;
⑨检测前, 向三个样品内分别加入磷脂标准品, 磷脂标准品为 双十二烷酰磷脂酰甘油、 双十二烷酰磷脂酰乙醇胺、 十二烷酰溶血 性磷脂酰乙醇胺和双十二烷酰磷脂酸,这四种磷脂标准品终浓度均 为 1.0 g/mL;
所述提取液是含有二丁基羟基甲苯的氯仿 /甲醇溶液,所述氯仿 /甲醇的体积比为 1.5:1,所述二丁基羟基甲苯的质量分数为 0.007%;
所述储存液为含有二丁基羟基甲苯的氯仿 /甲醇溶液,所述氯仿 /甲醇的体积比为 2:1, 所述二丁基羟基甲苯的质量分数为 0.007%;
( 6 ) LC- MS检测
采用 LC-MS对步骤(5 )获得的三个加入了磷脂标准品的样品 进行检测, 得到维生素 C生产菌株传代过程的磷脂组的分子结构见
表 1、 表 2和表 3和含量数据见图 9、 图 12和图 15;
LC-MS检测条件为:
色镨柱: Hypersil GOLD Silica, 其^ 为 150mm x 2.1mm,
5μπι;
进样量: 10 μί;
柱温: 25 °C;
流动相 A ( % ): 氯仿 ( 89.5 ), 甲醇( 10 ), 氢氧化铵 ( 0.5 ); 流动相 B ( % ): 氯仿 ( 55 ) , 甲醇( 39 ), 氢氧化铵( 0.5 ), 水(5.5 );
梯度程序: 0-7 min, 20-30% B; 7-15 min 30-40% B; 15-20 min 40-50% B; 20-25 min 50% B; 25-35min, 50-20% B;
35-45min, 20% B;
离子化方式: ESI (负离子方式) ;
扫描方式: MS Scan;
扫描范围: m/z 400-900;
扫描速度: 1000 scan/s;
毛细管电压: 3 KV;
锥孔电压: 30 V;
萃取电压 3 V;
离子源温度: 100°C;
脱溶剂气温度: 350°C;
锥孔气流量: 50 L/Hr
脱溶剂气流量: 400 L/Hr;
进 /出口能量: 50;
碰撞能量: 2;
HM1/LM1/HM2/LM2: 15.0;
Ion Energy 1: 1.0;
Ion Energy 2: 2.0;
(7)多元统计分析
将步骤( 6 )获得的维生素 C生产菌株传代过程的磷脂组的分子 含量数据, 进行多元统计分析, 得到区分不同传代时间维生素 C生 产菌株的差异磷脂分子标志物; 多元统计分析方法为 Pareto预处理 后进行主成分分析; 见图 10、 图 13和图 16;
(8)过程分析
将步骤(7)获得的差异磷脂分子标志物的含量按照不同传代 时间制成图表图 11、 图 14和图 17, 观察并分析这些磷脂分子变化的 规律,进而发现在混菌传代培养过程中起关键作用的磷脂分子及相 关代谢途径, 从而为以提高 2-酮基 -L-古龙酸为目的的菌种改造和 培养条件优化提供方向。 表 4-1巨大芽孢杆菌磷脂分子鉴定表
磷脂分子 巨大芽孢杆菌
PG27:0, PG28:1, PG28:0, PG29:1, PG29:0, PG30:1, PG30:0, 磷脂酰甘油
PG31:2, PG31:1, PG31:0, PG32:2, PG32:1, PG32:0, PG33:2,
(PG)
PG33:1, PG33:0, PG34:2, PG34:1, PG34:0, PG35:1, PG35:0
PE27:0, PE28:1, PE28:0, PE29:1, PE29:0, PE30:1, PE30:0, 磷脂酰乙醇胺 PE31:2, PE31:1, PE31:0, PE32:2, PE32:1, PE32:0, PE33:2, (PE) PE33:1, PE33:0, PE34:2, PE34:1, PE35:0, PE36:0, PE37:0,
PE38:0 溶血性磷脂酰
LPE13:0, LPE14:0, LPE15:0, LPE16:0
乙醇胺(LPE)
PA28:0, PA29:1, PA29:0, PA30:1, PA30:0, PA31:1, PA31:0, 磷脂酸(PA)
PA32:1, PA32:0, PA33:1, PA33:0 如表 4-1所示,通过本发明的方法提取并检测维生素 C生产菌株
(巨大芽孢杆菌 )传代过程磷脂组磷脂分子共 58种, 其中磷脂酰甘 油分子 21种, 磷脂酰乙醇胺分子 22种, 溶血性磷脂酰乙醇胺分子 4 种, 磷脂酸分子 11种。 表 4-2 氧化葡糖杆菌磷脂分子鉴定表
磷脂分子 氧化葡糖杆菌
PG28:1, PG28:0, PG29:0, PG31:0, PG32:1, PG32:0, PG33:1, 磷脂酰甘油(PG) PG33:0, PG34:2, PG34:1, PG34:0, PG35:2, PG35:1, PG35:0,
PG36:3, PG36:2, PG36:1, PG37:2, PG37:1, PG38:1, PG38:0 磷脂酸(PA) PA28:0 如表 4-2所示,通过本发明的方法提取并检测维生素 C生产菌株 氧化葡糖杆菌磷脂分子共 22种, 其中磷脂酰甘油分子 21种, 磷脂酸 分子 1种。
表 4-3 混菌磷脂分子鉴定表
磷脂分子 巨大芽孢杆菌
PG27:0, PG28 :1, PG28:0, PG29:1, PG29:0, PG30:1, PG30:0, 磷脂酰甘油
PG31:2, PG31 :1, PG31:0, PG32:2, PG32:1, PG32:0, PG33:2, (PG)
PG33:1, PG33 :0, PG34:2, PG34:1, PG34:0, PG35:1, PG35:0
PE27:0, PE28: 1, PE28:0, PE29:1, PE29:0, PE30:1, PE30:0, 磷脂酰乙醇胺
PE31:2, PE31: 1, PE31:0, PE32:2, PE32:1, PE32:0, PE33:2, (PE)
PE33:1, PE33: 0, PE34:2, PE34:1, PE35:2, PE37:0
溶血性磷脂酰
LPE13:0, LPE14:0, LPE15:0, LPE16:0, LPE17:0, LPE18:1 乙醇胺( LPE )
PA27:0, PA28:0, PA29:1, PA29:0, PA30:1, PA30:0, PA31:1, 磷脂酸(PA ) PA31:0, PA32:1 , PA32:0, PA33:1 , PA33:0, PA34:3, PA34:2,
PA34:1 , PA35:3
如表 4-3所示,通过本发明的方法提取并检测维生素 C生产菌株 混菌磷脂分子共 63种, 其中磷脂酰甘油分子 21种, 磷脂酰乙醇胺分 子 20种, 溶血性磷脂酰乙醇胺分子 6种, 磷脂酸分子 16种。
图 9中, 巨大芽孢杆菌细胞在传代时间为 0、 50、 100和 150天时, 细胞磷脂总含量分别为 10.89, 6.80, 7.06和 8.64 nmol/mg细胞干重, 显示出在两菌共同传代时间到第 50天时, 巨大芽孢杆菌细胞磷脂总 量显著下降,再随传代增加( 100、 150天)而緩慢上升的变化趋势。 以 0、 50、 100和 150天的巨大芽孢杆菌磷脂样本中的所有磷脂分子 的含量为矩阵, 进行主成分分析(图 10 ) , 得分图显示传代 0天和 50天细胞磷脂成分区别最大(距离最远), 而 100和 150天逐渐接近 0天细胞; 荷载图显示大多数 PG分子与 0天细胞成正相关, 而传代 50天后, 若干 PE和 LPE分子含量显著增加, 而在 100天时, PA分子 含量较高。 图 11为主成分分析荷载图中离群点(分子标志物)的含 量变化。 其中 PE34:2、 PE34:1和 LPE16:0在 50天细胞中含量最高; 一系列 PG分子在 50天含量最低, 之后逐渐上升; 一系列 PA分子在 50天明显下降, 在 100天又发生激增。 以上变化表明, 随两菌传代 共同传代时间增加, 磷脂代谢过程发生重大变化。 在巨大芽孢杆菌 中, LPE和 PA分子的增加,表明诱导细胞凋亡的信号转导事件发生 的概率增加, 而这种信号事件可能与巨大芽孢杆菌产孢密切相关, 进而影响小菌, 即氧化葡糖杆菌的生长和生产。
图 12中, 氧化葡糖杆菌细胞在传代时间为 0、 50、 100和 150天 时, 细胞磷脂总含量分别为 5.92, 1.42, 0.96和 0.85 nmol/mg细胞干 重, 表明氧化葡糖杆菌细胞磷脂总含量在传代 50天后, 显著下降。 以 0、 50、 100和 150天的氧化葡糖杆菌磷脂样本中的所有磷脂分子 的含量为矩阵, 进行主成分分析(图 13 ) , 得分图显示 0和 50天细 胞磷脂成分明显区分, 而 100和 150天细胞与 50天细胞差异不大; 荷 载图显示传代 50天后, PA分子含量增加。 图 14为区分不同传代时 间的分子标志物百分含量变化图,其中 PA28:0含量随传代时间延长 呈上升趋势。
图 15中, 混菌细胞在传代数为 0、 50、 100和 150天时, 细胞磷 脂总含量分别为 8.39, 6.33, 6.62和 7.91 nmol/mg细胞干重, 显示细 胞磷脂总含量在传代 50天时显著下降, 而后增加的趋势。 以 0、 50、 100和 150天的混菌磷脂样本中的所有磷脂分子的含量为矩阵,进行 主成分分析(图 16 ) , 得分图显示 0、 50、 100和 150天细胞磷脂成 分明显区分, 且在第一主成分方向顺序分布, 表明混菌细胞磷脂组 成随传代数增加而逐渐变化的趋势; 荷载图显示大多数 PG和 LPE 分子与 0天细胞成正相关, 而随传代进行, PE和 PA分子含量增加。 图 17为区分不同传代数的混菌的磷脂分子标志物。 其中一系列 PG 和 LPE分子随传代下降, 而 PE和 PA分子, 有随之增加的趋势。 这 表明随两菌传代时间增加,相互作用时间延长,磷脂代谢发生变化; LPE的减少和 PA的增加,提示不同的磷脂代谢相关酶类在两菌共同 传代和细胞膜信号转导中的不同作用。
实施例 4-2
一种分析维生素 C生产菌株传代过程磷脂组变化的方法, 其特 征是包括如下步骤:
( 1 ) 固体培养:
取 ΙΟμί保藏于体积浓度为 15%的甘油水溶液中的氧化葡糖杆 菌( Gluconobacter oxydans )和 ΙΟμί保藏于体积浓度为 15%的甘油 水溶液中的巨大芽孢杆菌 (Bacillus megaterium)分别接种于固体培 养基上, 28°C, 培养 48小时;
( 2 )种子培养:
将经步骤(1 )培养的巨大芽孢杆菌和氧化葡糖杆菌分别转入 种子培养基, 在 28°C, 200 rpm摇床振荡培养, 48h, 得到巨大芽孢 杆菌种子液和氧化葡糖杆菌种子液;
将巨大芽孢杆菌和氧化葡糖杆菌接种到新的种子培养基中,使 巨大芽孢杆菌的密度为 2xl07cfu/mL , 使氧化葡糖杆菌的密度为 2xl08cfu/mL, 在 28°C, 200rpm摇床振荡培养, 以 24h为传代周期, 以体积比为 1%为传代比接入新的种子培养基中, 传代 130天, 分别 在第 0天、 第 20天、 第 40天、 第 80天和第 130天取 5个样;
( 3 )分纯:
将步骤(2 )获得的 5个传代培养混菌菌株划线分纯, 再分别接 种于固体培养基上, 28°C培养 24小时; 再分别转入种子培养基, 在 28°C, 200 rpm摇床振荡培养 48h,得到进化了的巨大芽孢杆菌种子 液和进化了的氧化葡糖杆菌种子液;
( 4 )发酵:
将所述进化了的巨大芽孢杆菌、进化了的氧化葡糖杆菌以及混 合的进化了的巨大芽孢杆菌和进化了的氧化葡糖杆菌分别接种到 发酵培养基中, 使进化了的巨大芽孢杆菌的密度为 2xl07 cfu/mL , 使进化了的氧化葡糖杆菌的密度为 2xl08 cfu/mL,在 28°C, 200rpm 摇床振荡培养 15h;
( 5 )细胞磷脂组的提取:
①取在步骤( 4 )摇床振荡培养 10h的三种细胞悬液 lOOmL, 1000
rpm离心 10 min, 去除上清液, 保留细胞, 用 pH= 7.2的磷酸盐緩冲 液洗细胞 1次, 相同条件离心, 去除上清, 得到细胞;
②将步骤①所得细胞使用液氮在研钵内研磨制成干粉, 称取 200mg细胞干粉, 置于离心管 A中, 加入 0.5 mL超纯水, 充分混匀;
③向离心管 A中再加入 2 mL提取液, 充分混匀; 1000 rpm离心 10 min, 使溶液分层, 取下层有机溶剂层, 置于离心管 B中;
④重复步骤③ 2次, 至细胞完全沉降;
⑤向离心管 B中, 加入 O.8mol/L KC1水溶液 0.5mL, 充分混匀, 2000 rpm离心 10 min, 除去含水溶性杂质的上清;
⑥再向离心管 B加入 1 mL超纯水, 充分混匀, 2000 rpm离心 10 min, 去上清;
⑦ 40°C减压蒸馏步骤⑥所得混合物中的有机溶剂,得到总磷脂 提取混合物;
⑧将所述总磷脂提取混合物溶于 0.2 mL储存液中制成样品,冷 冻 -40°C以下保存;
⑨检测前, 向所述样品内加入磷脂标准品, 磷脂标准品为默二 十烷酰磷脂酰甘油、 双二十烷酰磷脂酰乙醇胺, 这两种磷脂标准品 终浓度均为 0.5 g/mL;
所述提取液是含有二丁基羟基甲苯的氯仿 /甲醇溶液,所述氯仿 /甲醇的体积比为 1:1, 所述二丁基羟基甲苯的质量分数为 0.005%;
所述储存液为含有二丁基羟基甲苯的氯仿 /甲醇溶液,所述氯仿 /甲醇的体积比为 1:1, 所述二丁基羟基甲苯的质量分数为 0.005%;
( 6 ) LC- MS检测
采用 LC-MS对步骤(5 )获得的加入了磷脂标准品的样品进行 检测, 得到维生素 C生产菌株传代过程的磷脂组的分子结构和含量 数据;
LC-MS检测条件为同实施例 4-1;
( 7 )多元统计分析
将步骤( 6 )获得的维生素 C生产菌株传代过程的磷脂组的分子 含量数据, 进行多元统计分析, 得到区分不同传代时间维生素 C生 产菌株的差异磷脂分子标志物; 多元统计分析方法为 Pareto预处理 后进行主成分分析;
( 8 )过程分析
将步骤(7 )获得的差异磷脂分子标志物的含量按照不同传代 时间制成图表, 观察并分析这些磚脂分子变化的规律, 进而发现在 混菌传代培养过程中起关键作用的磷脂分子及相关代谢途径,从而 为以提高 2-酮基 -L-古龙酸为目的的菌种改造和培养条件优化提供 方向。
实施例 4-3
一种分析维生素 C生产菌株传代过程磷脂组变化的方法, 其特 征是包括如下步骤:
( 1 ) 固体培养:
取 500μί保藏于体积浓度为 30%的甘油 7J溶液中的氧化葡糖杆 菌 ( Gluconobacter oxydans )和 500μί保藏于体积浓度为 30%的甘 油水溶液中的巨大芽孢杆菌 (Bacillus megaterium)分别接种于固体 培养基上, 35°C, 培养 24小时;
( 2 )种子培养:
将经步骤(1 )培养的巨大芽孢杆菌和氧化葡糖杆菌分别转入 种子培养基, 在 35°C, 280 rpm摇床振荡培养, 24h, 得到巨大芽孢 杆菌种子液和氧化葡糖杆菌种子液;
将巨大芽孢杆菌和氧化葡糖杆菌接种到新的种子培养基中,使 巨大芽孢杆菌的密度为 2xlOie cfu/mL , 使氧化葡糖杆菌的密度为
2xlOn cfu/mL,在 35°C, 280 rpm摇床振荡培养,以 48h为传代周期, 以体积比为 10%为传代比接入新的种子培养基中, 传代 100天, 分 别在第 0天、 第 50天和第 100天取 3个样;
( 3 )分纯:
将步骤(2 )获得的 3个传代培养混菌菌株划线分纯, 再分别接 种于固体培养基上, 35°C培养 48小时; 再分别转入种子培养基, 在 35°C, 280 rpm摇床振荡培养 24h,得到进化了的巨大芽孢杆菌种子 液和进化了的氧化葡糖杆菌种子液;
( 4 )发酵:
将所述进化了的巨大芽孢杆菌、进化了的氧化葡糖杆菌以及混 合的进化了的巨大芽孢杆菌和进化了的氧化葡糖杆菌分别接种到 发酵培养基中,使进化了的巨大芽孢杆菌的密度为 2xl01G cfu/mL , 使进化了的氧化葡糖杆菌的密度为 2xlOu cfu/mL,在 35°C,280 rpm 摇床振荡培养 10h;
( 5 )细胞磷脂组的提取:
①取在步骤( 4 )摇床振荡培养 15h的三种细胞悬液 200mL, 3000 rpm离心 3min, 去除上清液, 保留细胞, 用 pH=7.4的磷酸盐緩冲液 洗细胞 3次, 相同条件离心, 去除上清, 得到细胞;
②将步骤①所得细胞使用液氮在研钵内研磨制成干粉, 称取 300 mg细胞干粉, 置于离心管 A中,加入 0.8 mL超纯水, 充分混匀;
③向离心管 A中再加入 4 mL提取液, 充分混匀; 3000 rpm离心 3min, 使溶液分层, 取下层有机溶剂层, 置于离心管 B中;
④重复步骤③ 4次, 至细胞完全沉降;
⑤向离心管 B中,加入 1.2 mol/L KCl7j溶液 1.5 mL,充分混匀, 4000 rpm离心 3 min, 除去含水溶性杂质的上清;
⑥再向离心管 B加入 3 mL超纯水, 充分混匀, 4000 rpm离心 3
miii, 去上清;
⑦氮气吹干步骤⑥所得混合物中的有机溶剂,得到总磷脂提取 混合物;
⑧将所述总磷脂提取混合物溶于 2 mL储存液中制成样品,冷冻 _40°C以下保存;
⑨检测前, 向所述样品内加入磷脂标准品, 磷脂标准品为默癸 烷酰磷脂酰甘油、 双癸烷酰磷脂酰乙醇胺和双十二烷酰磷脂酸, 使 这三个磷脂标准品终浓度均为 1.5 g/mL;
所述提取液是含有二丁基羟基甲苯的氯仿 /甲醇溶液,所述氯仿 /甲醇的体积比为 2:1, 所述二丁基羟基甲苯的质量分数为 0.01%;
所述储存液为含有二丁基羟基甲苯的氯仿 /甲醇溶液,所述氯仿 /甲醇的体积比为 4:1, 所述二丁基羟基甲苯的质量分数为 0.01%;
( 6 ) LC- MS检测
采用 LC-MS对步骤(5 )获得的加入了磷脂标准品的样品进行 检测, 得到维生素 C生产菌株传代过程的磷脂组的分子结构和含量 数据;
LC-MS检测条件为同实施例 4-1;
( 7 )多元统计分析
将步骤( 6 )获得的维生素 C生产菌株传代过程的磷脂组的分子 含量数据, 进行多元统计分析, 得到区分不同传代时间维生素 C生 产菌株的差异磷脂分子标志物; 多元统计分析方法为 Pareto预处理 后进行主成分分析;
( 8 )过程分析
将步骤(7 )获得的差异磷脂分子标志物的含量按照不同传代 时间制成图表, 观察并分析这些磚脂分子变化的规律, 进而发现在 混菌传代培养过程中起关键作用的磷脂分子及相关代谢途径,从而
为以提高 2-酮基 -L-古龙酸为目的的菌种改造和培养条件优化提供 方向。
实验证明, 实施例 4-2和实施例 4-3与实施例 4-1的结果类似。 本发明所采用的固体培养基、种子培养基和发酵培养基的组成 选自中国专利申请号为 201110314740.9公开的培养基, 例如:
固体培养基:按比例称取 L-山椠糖 20 g,玉米浆 3 g,牛肉骨 3 g, 酵母浸粉 3 g, 尿素 1 g,蛋白胨 10 g,琼脂 20 g, KH2P04 1 g, MgS04
0.2 g, CaC03 1 g, 加水至 1 L, 调 pH=6.8, 1210C灭菌 20 min, 制 成固体培养基。
种子培养基:按比例称取 L-山椠糖 20 g,玉米浆 3 g,牛肉骨 3 g, 酵母浸粉 3 g, 尿素 l g, 蛋白膝 10 g, KH2P04 1 g, MgS04 0.2 g, CaC03 l g, 加水至 1 L, 调 pH=6.8, 121。C灭菌 20 min, 制成种子 培养基。
发酵培养基:按比例称取 L-山椠糖 80 g,玉米浆 20 g,尿素 12 g, KH2P04 lg, MgS04 0.5g, CaC03 lg,加水至 1 L,调 pH=7.0, 121°C 灭菌 20min, 制成发酵培养基。 实施例 5-1
一种检测维生素 C生产菌株传代过程中营养环境变化的方法, 包括如下步骤:
( 1 )混菌传代培养:
①固体培养:
于液氮的 500 保藏于体积浓度为 15%的甘油水溶液中 的氧化葡糖杆菌( Gluconobacter oxydans )和 500 保藏于体积浓 度为 15%的甘油水溶液中的巨大芽孢杆菌 (Bacillus megaterium)分 别接种于固体培养基上, 28°C , 培养 24 h;
②种子培养:
将经步骤(1 )①培养的巨大芽孢杆菌和氧化葡糖杆菌分别转 入种子培养基, 在 28。C, 200 r/min摇床振荡培养 24h, 得到巨大芽 孢杆菌种子液和氧化葡糖杆菌种子液;
将巨大芽孢杆菌和氧化葡糖杆菌接种到新的种子培养基中,使 巨大芽孢杆菌的密度为 2xl07 CFU/mL, 使氧化葡糖杆菌的密度为 2xl08 CFU/mL, 在 28。C, 200 r/min摇床振荡培养, 以 24h为传代周 期, 以体积比为 1%为传代比接入新的种子培养基中, 传代 150天得 到混菌细胞, 在传代 0-150天中选定 4个取样时间分别为 0天、 50天、 100天、 150天取 4个样;
③分纯:
将步骤( 1 )②获得的 4个样的混菌细胞划线分纯后再分别接种 于固体培养基上, 28 C培养 24 h; 再分别转入新的种子培养基, 在 28°C , 200 rpm摇床振荡培养 24 h, 分别得到巨大芽孢杆菌种子液 和氧化葡糖杆菌种子液; 保藏于体积浓度为 15%的甘油水溶液中;
④发酵:
将步骤(1 )③获得的巨大芽孢杆菌和氧化葡糖杆菌以及将两 种菌混合在一起的混合菌,分别接种到新的种子培养基中,使巨大芽 孢杆菌的密度为 2xl07 CFU/mL , 氧化葡糖杆菌的密度为 2xl08 CFU/mL, 在 28。C, 200 r/min摇床振荡培养 10 h;
( 2 )营养环境中物质的测定:
①培养液的收集:
分别取步骤(1 )④⑤获得的巨大芽孢杆菌培养液、 氧化葡糖 杆菌培养液和混菌体系培养液 1 mL, 以 5000 rpm的转速离心, 收 集上清, 并用 0.22 μπι纤维素微孔滤膜过滤;
②样品制备:
取步骤( 2 )①获得的滤液 10 置于离心管中, 加入 50 的 0.04 mg/ml氘标记的琥珀酸甲醇溶液为内标物, 冷冻干燥; 加入 40 浓度为 20 mg/mL的甲氧基胺盐酸盐的吡啶溶液于 30。C水浴中肟 化反应 60 min; 再加入 50 μίΝ-甲基 -N-三甲^ 烷三氟乙酰胺于 35。C水浴进行硅烷化反应 30 min;
③ GC-TOFMS检测:
将 1 步骤( 2 )③获得样品进到气相色谱中, 色谱柱为
DB-5MS , 所述色镨柱的规格为 30 mx0.25 mm i.d., 进样口温度 250。C, 载气为高纯氦气, 流速 0.6 ml/min, 分流比 3: 1, 柱温箱升 温程序为: 初始 50。C, 保持 2 min, 以 4。C/min的速度升到 260。C, 保持 3 min, 使用 EI电离源, 源温 230°C, 检测器电压 2300 V, 电离 电压 60 eV, 电流 30 μΑ; 质傳检测范围 50-800 m/z; 营养环境物质 的鉴定使用 NIST 2005数据库, 质傳数据的处理和营养环境物质相 对含量的测定使用 Masslynx 4.1软件; 并通过对色傳峰面积积分处 理, 并与内标物的峰面积对照, 得到营养环境物质的相对含量; ( 3 )主成分分析:
①将步骤( 2 )获得的营养环境物质的相对含量的数据进 行 Pareto预处理;
②用 Metlab 7.0 ( Mathworks. Inc. )软件对步骤( 3 ) ® ^处理 后的数据进行主成分分析,得到差异营养环境标志物;
得到用于表达样^目似性和差异性的得分图和载荷图;在得分 图中, 样品点相互之间距离越近, 说明样本的相似度越大, 距离越 远, 说明样本差异越大, 用来比较不同代数巨大芽孢杆菌、 氧化葡 糖杆菌和混菌体系传代培养过程中营养环境的相似和差异;在载荷 图中, 每个点表示各营养成分, 距离中心点距离越远的物质, 其在 传代培养的过程中的差异就越大,便可作为传代培养营养环境变化
的标志物; 见图 18、 图 20和图 22。
( 4 )过程分析
将差异营养环境标志物的相对含量按照不同传代时间制成图 表图 19、 图 21和图 23, 观察并分析这些物质变化的^ , 检测 出维生素 C生产菌株传代过程中营养环境的变化, 进而发现在混菌 传代培养过程中起关键作用的营养环境成分,从而为揭示混菌传代 培养过程中两菌的相互作用机制和培养条件优化提供了方向。
表 5-1 氧化葡糖杆菌传代培养过程中营养环境物质鉴定表 赤藓糖 葡萄糖 呋喃核糖 木鲷糖 山歸
核糖 Ν-乙酰氣基葡萄糖
半乳糖
丙氨酸 苏氨酸 ^^酸
缬氨酸 脯氨酸 苯丙氨酸 异亮氨酸 天冬氛酸 半胱氨酸
^酸 甘氨酸 丁酸 赖氨酸
丝氨酸 鸟氨酸 酪氛酸
甲硫氨酸 4-羟基脯氨酸 精氨酸
5-鲷脯氨酸 色氨酸
l醇 甘露醇 核糖醇
糖的衍生物 2-鲷基 -L-古龙酸 葡糖酸 2-鲷基葡萄糖酸 赤藓糖醇 半乳糖酸 葡萄糖醇 丙鲷酸 乳酸 草酸
甘油酸 2,3,4-三羟基丁酸 丁烯二酸 有机酸
磷酸 苹果酸 柠椽酸
丁二酸 辛酸 2-氧代己酸
3-羟基丙酸 3-羟基丁酸 羟乙酸
2,4-二羟基丁酸 2-氧代-戊二酸 4-羟基苯乙酸
2-羟基 -3-甲基丁酸 2-羟基 -4-甲基戊酸 吡咯 酸 脂肪酸 正十六 ^肪酸 正十八 肪酸
尿素 2-幾基乙胺 1 , 4-丁二胺
1 , 5-戊二胺 尿嘧啶 胸腺嘧啶
其他
甘油 天冬酰胺 尿酸 肌醇 甘油 如表 5-1所示, 通过本发明的方法检测维生素 C生产菌株(氧化 葡糖杆菌)传代过程营养环境物质共 74种, 其中糖 11种, 氛基酸 20 种, 糖的衍生物 9种, 有机酸 21种, 脂肪酸 2种, 胺类及含氮化合物 等其他物质 11种。 表 5-2 巨大芽孢杆菌传代培养过程中营养环境物质鉴定表
赤藓糖 葡萄糖 呋喃核糖
木鲷糖 山歸
核糖 N-乙酰氣基葡萄糖
半乳糖
丙氨酸 苏氨酸 ^^酸
缬氨酸 脯氨酸 苯丙氨酸
异亮氨酸 天冬氛酸 半胱氨酸
^酸 甘氨酸 丁酸 赖氨酸
丝氨酸 鸟氨酸 酪氛酸
甲硫氨酸 4-羟基脯氨酸 精氨酸
5-鲷脯氨酸 色氨酸
l醇 甘露醇 核糖醇 糖的衍生物 葡萄糖醇 葡糖酸 2-鲷基葡萄糖酸 赤藓糖醇 半乳糖酸
丙鲷酸 乳酸 草酸 甘油酸 2,3,4-三羟基丁酸 丁烯二酸
磷酸 苹果酸 柠椽酸
丁二酸 辛酸 2-氧代己酸
3-羟基丙酸 3-羟基丁酸 羟乙酸
2,4-二羟基丁酸 2-氧代-戊二酸 4-羟基苯乙酸
2-幾基 -4-甲基戊酸 2- J>苯甲酸 吡咯 酸
2-羟基 -3-甲基丁酸
脂肪酸 正十六 ^肪酸 正十八 肪酸
尿素 2-幾基乙胺 1, 4-丁二胺
1, 5-戊二胺 尿嘧啶 胸腺嘧啶
其他
甘油 天冬酰胺 尿酸 肌醇 次黄嘌呤 如表 5-2所示, 通过本发明的方法检测维生素 C生产菌株(巨大 芽孢杆菌)传代过程营养环境物质共 74种, 其中糖 11种, 氛基酸 20 种, 糖的衍生物 8种, 有机酸 22种, 脂肪酸 2种, 胺类及含氮化合物 等其他物质 11种。
表 5-3 混菌传代培养过程中营养环境物质鉴定表
赤藓糖 葡萄糖 呋喃核糖 木鲷糖 山椠糖
核糖 N-乙酰氣基葡萄糖
半乳糖
丙氨酸 苏氨酸 ^^酸
缬氨酸 脯氨酸 苯丙氨酸 异亮氨酸 天冬氛酸 半胱氨酸
^酸 甘氨酸 丁酸 赖氨酸
丝氨酸 鸟氨酸 酪氛酸 甲硫氨酸 4-羟基脯氨酸 精氨酸
5-鲷脯氨酸 色氨酸
l醇 甘露醇 核糖醇
糖的衍生物 葡萄糖醇 葡糖酸 2-嗣基葡萄糖酸 赤藓糖醇 半乳糖酸 2-鲷基 -L-古龙酸 丙鲷酸 乳酸 草酸 甘油酸 2,3,4-三羟基丁酸 丁烯二酸
磷酸 苹果酸 柠椽酸 丁二酸 辛酸 2-氧代 -己酸
3-羟基丙酸 3-羟基丁酸 羟乙酸
2,4-二羟基丁酸 2-氧代-戊二酸 4-羟基苯乙酸 丙二酸 2- J>苯甲酸 吡咯 -2-羧酸
2-羟基 -3-甲基丁酸 2-羟基 -4-甲基戊酸 2-氧代 -3甲基 -丁酸 脂肪酸 正十六^旨肪酸 正十八 肪酸
尿素 2-幾基乙胺 1 , 4-丁二胺
1 , 5-戊二胺 尿嘧啶 胸腺嘧啶 其他
甘油 天冬酰胺 尿酸 肌醇 次黄嘌呤 如表 5-3所示,通过本发明的方法检测维生素 C生产菌株混菌传 代过程营养环境物质共 77种, 其中糖 11种, 氛基酸 20种, 糖的衍生
物 9种, 有机酸 24种, 脂肪酸 2种, 胺类及含氮化合物等其他物质 11 种。
以 0、 50、 100和 150代的氧化葡糖杆菌传代培养的营养环境物 质的相对含量为样本矩阵, 进行主成分分析(图 18 ) , 得分图显 示明显可以分为四类, 载荷图显示随着传代的进行, 培养液环境中 某些氛基酸的含量显著增加。 图 19为区分不同传代时间的分子标志 物相对含量变化图, 其中纈氨酸、 异亮氨酸、 脯氨酸、 甘氛酸、 丙 氨酸、 丝氨酸、 5-酮脯氨酸、 酪氛酸和色氨酸随着传代的时间的延 长呈上升趋势, 且高于空白培养基, 它们是氧化葡糖杆菌降解蛋白 质的结果, 这些物质的积累为大菌的生长提供了足够的营养。
如图 20所示, 以 0、 50、 100和 150代的巨大芽孢杆菌传代培养 的营养环境物质的相对含量为样本矩阵, 进行主成分分析, 得分图 显示可以有效分为四类, 载荷图中 5种分子标志物在第一主成分方 向上顺序分布, 表明这些标志物随着代数增加而逐渐变化的趋势。 图 21为区分不同传代时间巨大芽孢杆菌培养环境中分子标志物相 对含量的随时间变化趋势。 除赤藓糖和 4-羟基脯氨酸外, 其余标志 物分子的含量均低于空白培养基,我们可以认为他们能被大菌利于 用于生长和自身物质的合成。 随着传代时间的延长, 脯氨酸和甘氨 酸含量逐渐降低, 尤其是 150代大菌培养环境中含量最低, 明显低 于出发菌株。 大菌体内积累更多的脯氨酸, 有助于抵抗环境胁迫; 甘氨酸对细胞膜具有重要作用, 高浓度的甘氨酸有助于增加细胞膜 的通透性, 随着传代的增加, 大菌对甘氛酸的利用能力增强, 有助 于混菌培养时大菌胞内代谢物的幹放, 从而促进 2-KLG的合成。 培 养环境中赤藓糖和 4-羟基脯氨酸浓度高于空白培养基, 可见它们是 大菌在胞外积累的结果, 且这两种标志物分子随着传代时间的延 长, 浓度逐渐提高, 在 150代大菌传代环境中达到最大。 其中赤藓
糖是芳香族氛基酸和维生素 B6的合成前体, 能够辅助氧化葡糖杆菌 合成 ^酸并改善碳中心代谢能力。
图 22中, 混菌细胞在传代时间为 0、 50、 100和 150天时以混菌 营养环境中的物质的相对含量为样本矩阵进行主成分分析,得分图 显示 50代和 100代的混菌较为接近, 0代混菌明显与进化的混菌区分 很大。 在载荷图中可以看到区分样本的关键性差异分子标志物, 即 草酸、 脯氨酸、 丙二酸、 5-酮脯氨酸、 果糖、 酪氛酸、 半乳糖酸、 十六烷酸、 1,5-戊二胺、 十八烷酸和色氨酸。 这些标志物随着传代 时间的延长, 在培养环境中含量成降低趋势, 尤其 Ut氨酸和 5-酮 脯氨酸在 150代混菌中浓度达到最低(图 23 ) , 这两种物质是影响 混菌发酵 2-KLG产量的关键物质。 以上变化表明, 随着两菌传代时 间的增加, 相互作用时间延长, 两菌的营养环境发生变化, 这些营 养物质的减少, 提示进化后的混菌的配合关系更好。
实施例 5-2
一种检测维生素 C生产菌株传代过程中营养环境变化的方法, 包括如下步骤:
( 1 )混菌传代培养:
①固体培养:
于液氮的 10 保藏于体积浓度为 20%的甘油水溶液中的 氧化葡糖杆菌 ( Gluconobacter oxydans )和 10 保藏于体积浓度 为 20%的甘油水溶液中的巨大芽孢杆菌 (Bacillus megaterium)分别 接种于固体培养基上, 30°C , 培养 36 h;
②种子培养:
将经步骤(1 )①培养的巨大芽孢杆菌和氧化葡糖杆菌分别转 入种子培养基, 在 30。C, 250 r/min摇床振荡培养 36h, 分别得到巨 大芽孢杆菌种子液和氧化葡糖杆菌种子液;
将巨大芽孢杆菌和氧化葡糖杆菌接种到一个新的种子培养基 中, 使巨大芽孢杆菌的密度为 2xl08 CFU/mL, 使氧化葡糖杆菌的 密度为 2xl09 CFU/mL, 在 30。C, 250r/min摇床振荡培养, 以 36h为 传代周期, 以体积比为 5%为传代比接入新的种子培养基中, 传代 100天得到混菌细胞, 在传代 0-100天选定 3个取样时间取 3个样, 分 别为 0天、 50天、 100天;
③分纯:
将步骤( 1 )②获得的 3个样的混菌细胞划线分纯后再分别接种 于固体培养基上, 30 C培养 36 h; 再分别转入新的种子培养基, 在 30°C , 250 rpm摇床振荡培养 36 h, 分别得到巨大芽孢杆菌种子液 和氧化葡糖杆菌种子液; 保藏于体积浓度为 20%的甘油水溶液中;
④发酵:
将步骤(1 )③获得的巨大芽孢杆菌和氧化葡糖杆菌以及将两 种菌混合在一起的混合菌, 分别接种到新的种子培养基中, 使巨大 芽孢杆菌的密度为 2xl08 CFU/mL , 氧化葡糖杆菌的密度为
2xl09CFU/mL, 在 30。C, 250 r/min摇床振荡培养 12 h;
( 2 )营养环境中物质的测定:
①培养液的收集:
分别取步骤(1 )④获得的巨大芽孢杆菌培养液、 氧化葡糖杆 菌培养液和混菌体系培养液 1.5 mL, 以 8000 rpm的转速离心, 收集 上清, 并用 0.22 μπι纤维素微孔滤膜过滤, 得滤液;
②样品制备:
取步骤(2 )①所获得的滤液 20 置于离心管中,并加入 100 的 0.10 mg/ml氘标记的琥珀酸甲醇溶液为内标物, 冷冻干燥; 加入 80 浓度为 20 mg/mL的甲氧基胺盐酸盐的吡啶溶液于 37。C水浴 中 "化反应 90 mill; 再加入 80 μίΝ-甲基 -N-三甲基硅烷三氟乙酰胺
于 37。C水浴进行硅烷化反应 40 min;
③ GC-TOFMS检测:
将 1 步骤( 2 )②获得样品进到气相色谱中, 色谱柱为
DB-5MS , 所述色镨柱的规格为 30 mx0.25 mm i.d., 进样口温度 270。C, 载气为高纯氦气, 流速 0.8 ml/min, 分流比 20: 1, 柱温箱 升温程序为: 初始 60。C, 保持 3 min, 以 6。C/min的速度升到 280。C, 保持 5 min, 使用 EI电离源, 源温 250°C, 检测器电压 2500 V, 电离 电压 70 eV, 电流 40 μΑ; 质傳检测范围 50-800 m/z; 营养环境物质 的鉴定使用 NIST 2005数据库, 质傳数据的处理和营养环境物质相 对含量的测定使用 Masslynx 4.1软件; 并通过对色傳峰面积积分处 理, 并与内标物的峰面积对照, 得到营养环境物质的相对含量; ( 3 )主成分分析:
①将步骤(2 )获得的营养环境物质的相对含量的数据进行
Pareto预处理;
②用 Metlab 7.0 ( Mathworks. Inc. )软件对步骤( 3 ) ® ^处理 后的数据进行主成分分析,得到差异营养环境标志物用于表达样本 相似性和差异性的得分图和载荷图; 在得分图中, 样品点相互之间 距离越近,说明样本的相似度越大,距离越远,说明样本差异越大, 用来比较不同代数巨大芽孢杆菌、氧化葡糖杆菌和混菌体系传代培 养过程中营养环境的相似和差异; 在载荷图中, 每个点表示各营养 成分, 距离中心点距离越远的物质, 其在传代培养的过程中的差异 就越大, 便可作为传代培养营养环境变化的标志物。
( 4 )过程分析
将差异营养环境标志物的相对含量按照不同传代时间制成图 表, 观察并分析这些物质变化的规律, 进而发现在混菌传代培养过 程中起关键作用的营养环境成分,从而为揭示混菌传代培养过程中
两菌的相互作用机制和培养条件优化提供了方向。
实施例 5-3
一种检测维生素 C生产菌株传代过程中营养环境变化的方法, 包括如下步骤:
( 1 )混菌传代培养:
①固体培养:
取存于液氮的 200 保藏于体积浓度为 30%的甘油水溶液中 的氧化葡糖杆菌( Gluconobacter oxydans )和 200 保藏于体积浓 度为 30%的甘油水溶液中的巨大芽孢杆菌 (Bacillus megaterium)分 别接种于固体培养基上, 35°C , 培养 48 h;
②种子培养:
将经步骤(1 )①培养的巨大芽孢杆菌和氧化葡糖杆菌分别转 入种子培养基, 在 35。C, 280 r/min摇床振荡培养 48 h, 得到巨大芽 孢杆菌种子液和氧化葡糖杆菌种子液;
将巨大芽孢杆菌和氧化葡糖杆菌接种到一个新的种子培养基 中, 使巨大芽孢杆菌的密度为 2xlOie CFU/mL, 使氧化葡糖杆菌的 密度为 2xlOu CFU/mL, 在 35。C, 280 r/min摇床振荡培养, 以 48h 为传代周期, 以体积比为 10%为传代比接入新的种子培养基中, 在 传代 0-150天中选定 4个取样时间取 4个样, 分别为 0天、 50天、 100 天、 150天;
③分纯:
将步骤( 1 )②获得的 4个样的混菌细胞划线分纯后再分别接种 于固体培养基上, 35。C培养 48 h; 再分别转入新的种子培养基, 在 35°C , 280 rpm摇床振荡培养 48 h, 分别得到巨大芽孢杆菌种子液 和氧化葡糖杆菌种子液; 保藏于体积浓度为 30%的甘油水溶液中;
④发酵:
将步骤(1 )③获得的巨大芽孢杆菌和氧化葡糖杆菌以及两种 菌混合在一起的混合菌分别接种到种子培养基中,使巨大芽孢杆菌 的密度为 2xl01G CFU/mL ,氧化葡糖杆菌的密度为 2xlOuCFU/mL, 在 35。C, 280 r/min摇床振荡培养 15h;
( 2 )营养环境中物质的测定:
①培养液的收集:
分别取步骤(1 )④获得的巨大芽孢杆菌培养液、 氧化葡糖杆 菌培养液和混菌体系培养液 2 mL, 以 10000 rpm的转速离心, 收集 上清, 并用 0.22 μπι纤维素微孔滤膜过滤;
②样品制备 :
取步骤(2 )①所获得的滤液 50 置于离心管中,并加入 200 的 0.14 mg/ml氘标记的琥珀酸甲醇溶液为内标物, 冷冻干燥; 加入 100 浓度为 20 mg/mL的甲氧基胺盐酸盐的吡啶溶液于 40。C水浴 中 "化反应 120 min; 再加入 100 μίΝ-甲基 -N-三甲^ J 烷三氟乙酰 胺于 40 °C水浴进行硅烷化反应 60 min;
③ GC-MSTOF检测:
将 1 步骤( 2 )②获得样品进到气相色谱中, 色谱柱为
DB-5MS , 所述色镨柱的规格为 30 mx0.25 mm i.d., 进样口温度为 280。C, 载气为高纯氦气, 流速 0.7 ml/min, 分流比 5: 1, 柱温箱升 温程序为: 初始 80。C, 保持 5 min, 以 8。C/min的速度升到 300。C, 保持 8 min, 使用 EI电离源, 源温 260°C, 检测器电压 2700 V, 电离 电压 80 eV, 电流 50 μΑ; 质傳检测范围 50-800 m/z; 营养环境物质 的鉴定使用 NIST 2005数据库, 质傳数据的处理和营养环境物质相 对含量的测定使用 Masslynx 4.1软件; 并通过对色傳峰面积积分处 理, 并与内标物的峰面积对照, 得到营养环境物质的相对含量; ( 3 )主成分分析:
①将步骤(2 )获得的营养环境物质的相对含量的数据进行
Pareto预处理;
②用 Metlab 7.0 ( Mathworks. Inc. )软件对步骤( 3 ) ® ^处理 后的数据进行主成分分析,得到用于表达样本相似性和差异性的得 分图和载荷图; 在得分图中, 样品点相互之间距离越近, 说明样本 的相似 大, 距离越远, 说明样本差异越大, 用来比较不同代数 巨大芽孢杆菌、氧化葡糖杆菌和混菌体系传代培养过程中营养环境 的相似和差异; 在载荷图中, 每个点表示各营养成分, 距离中心点 距离越远的物质, 其在传代培养的过程中的差异就越大, 便可作为 传代培养营养环境变化的标志物。
( 4 )过程分析
将差异营养环境标志物的相对含量按照不同传代时间制成图 表, 观察并分析这些物质变化的规律, 进而发现在混菌传代培养过 程中起关键作用的营养环境成分,从而为揭示混菌传代培养过程中 两菌的相互作用机制和培养条件优化提供了方向。 实验证明, 实施例 5-2和实施例 5-3与实施例 5-1的结果类似。 本发明所采用的固体培养基、种子培养基的组成选自中国专利 申请号为 201110314740.9公开的培养基, 例如:
固体培养基:按比例称取 L-山椠糖 20 g,玉米浆 3 g,牛肉骨 3 g, 酵母浸粉 3 g, 尿素 1 g,蛋白胨 10 g,琼脂 20 g, KH2P04 1 g, MgS04
0.2 g, CaC03 1 g, 加水至 1 L, 调 pH=6.8, 1210C灭菌 20 min, 制 成固体培养基。
种子培养基:按比例称取 L-山椠糖 20 g,玉米浆 3 g,牛肉骨 3 g, 酵母浸粉 3 g, 尿素 l g, 蛋白膝 10 g, KH2P04 1 g, MgS04 0.2 g, CaC03 l g, 加水至 1 L, 调 pH=6.8, 121。C灭菌 20 min, 制成种子
培养基。 实施例 6-1
一种分析维生素 C生产菌株传代过程小分子代谢物变化的方 法, 其特征是包括如下步骤:
( 1 )混菌传代培养:
①固体培养:
取液氮的 100 保藏于体积浓度为 20%的甘油水溶液中的氧 化葡糖杆菌( Gluconobacter oxydans )和 100 保藏于体积浓度为 20%的甘油水溶液中的巨大芽孢杆菌 (Bacillus megaterium)分别接 种于固体培养基上, 30*Ό , 培养 36 h;
( 2 )种子培养:
将经步骤(1 )①培养的巨大芽孢杆菌和氧化葡糖杆菌分别转 入种子培养基, 在 30 , 240 rpm摇床振荡培养 36 h, 分别得到巨 大芽孢杆菌种子液和氧化葡糖杆菌种子液;
将巨大芽孢杆菌和氧化葡糖杆菌接种到一个新的种子培养基 中, 使巨大芽孢杆菌的密度为 2xl08 CFU/mL, 使氧化葡糖杆菌的 密度为 Zxli^ CFU/mL, 在 30*Ό, 240 rpm摇床振荡培养, 以 36h为 传代周期, 以体积比为 5%为传代比接入新的种子培养基中, 传代 150天得到混菌细胞, 在传代第 0, 50, 100, 150天时间点取 4个样;
③分纯:
将步骤( 1 )②获得的 4个样的混菌细胞划线分纯后再分别接种 于固体培养基上, 30 培养 36 h; 再分别转入新的种子培养基, 在 30*Ό , 240 rpm摇床振荡培养 36 h, 分别得到进化了的巨大芽孢杆 菌种子液和氧化葡糖杆菌种子液;保藏于体积浓度为 20%的甘油水 溶液中;
④发酵:
将步骤(1 )③获得的进化了的巨大芽孢杆菌和氧化葡糖杆菌 以及将两种菌混合在一起的混合菌, 分别接种到新的种子培养基 中,使进化了的巨大芽孢杆菌的密度为 2xl08CFU/mL,进化了的氧 化葡糖杆菌的密度为 2xl01GCFU/mL, 在 30*Ό, 240rpm摇床振荡培 养 13 h;
( 2 )胞内小分子代谢物样品的制备和测定:
①各取在步骤( 1 )④获得的三种细胞悬液 150 mL,分别在 2000 rpm离心 5 min, 去除上清液, 保留细胞, 用 pH=7.3的磷酸盐緩冲 液洗细胞 2次, 相同^ ^离心, 去除上清, 得到细胞;
②将步骤(2 )①所得细胞用液氮研磨的方法制成干粉, 各称 取 50 mg细胞干粉, 分别置于三个离心管中, 再加入 1.0 mL提取液, 加入 50μί浓度为 0.040mg/mL氘标记的琥珀酸甲醇溶液为内标物, 混匀; 2000 111离心5 111111, 取上清液置于三个新的离心管中冷冻 干燥;
③将步骤(2 )②获得三个离心管中分别加入 50 浓度为 20 mg/mL的甲氧基胺盐酸盐的吡啶溶液于 30 水浴中肟化反应 90 min; 再加入 80 L N-甲基 -N-三甲基娃烷三氟乙酰胺于 37 水浴进 行硅烷化反应 30min;
所述提取液为体积分数为 50的甲醇水溶液;
④ GC-TOF/MS检测:
将 1 步骤( 2 )③获得的样品进到气相色 中, 色谱柱为 DB-5MS, 所述色镨柱的¾^为30 111 > 0.25 111111 1.(1., 进样口温度为 280 , 载气为高纯氦气, 恒压 91KPa, 分流比 10: 1, 柱温箱升温 程序为:初始 70*Ό,保持 5 min,以 5 /min的升到 280 ,保持 5 min, 使用 EI电离源, 源温 250 , 检测器电压 2500V, 电离电压 70 eV,
电流 40 μΑ; 质傳检测范围 50-800 m/z; 小分子代谢物的鉴定使用 NIST 2005数据库, 质谱数据的处理和代谢物相对含量的测定使用 Masslynx 4.1软件; 并通过对色傳峰面积积分处理, 并与内标物的 峰面积对照, 得到小分子代谢物的相对含量;
( 3 )主成分分析:
①将步骤( 2 )④获得的维生素 C生产菌株传代过程的小分子代 谢物的相对含量数据进行 Pareto预处理;
②用 SIMCA-P 11.5软件对预处理后的数据进行主成分分析,得 到区分不同传代时间维生素 C生产菌株的小分子代谢物标志物;
( 4 )过程分析
将小分子代谢物标志物的含量按照不同传代时间制成图表,观 察并分析小分子代谢物标志物变化的规律, 检测出维生素 C生产菌 株传代过程中细胞内小分子代谢物的变化。进而发现在混菌传代培 养过程中起关键作用的代谢物分子及相关代谢途径,从而为揭示混 菌传代培养过程中两菌的相互作用机制和以提高 2-酮基 -L-古龙酸 为目的的菌种改造和培养条件优化提供方向。
以 0、 50、 100和 150代的氧化葡糖杆菌传代培养的小分子代谢 物的相对含量为样本矩阵,进行主成分分析(图 24 )。其得分图(图 24-1 ) 明显可以分为四类, 其中 150代明显与 0、 50和 100代的代谢 物谱差异较远, 0代与 50代相距较近, 说明其传代进化差异不是很 大。 图 25为区分氧化葡糖杆菌不同传代时间的分子标志物相对含量 变化图, 其中十六烷酸、 十八烯酸和十八烷酸随着传代时间的延长 含量降低, 说明细胞生长过程中消耗更多的脂肪酸生成细胞膜磷 脂, 因此游离脂肪酸在 100代后显著减少。
以 0、 50、 100和 150代的巨大芽孢杆菌传代培养的小分子代谢 物的相对含量为样本矩阵,进行主成分分析(图 26 ),从得分图(图
26-1 ) 中可以看出巨大芽孢杆菌不同传代培养的代谢物谱差异较 大, 明显分为四类。 图 27为区分不同传代时间巨大芽孢杆菌小分子 代谢标志物随时间的变化其相对含量的变化趋势图。其中十六烷酸 和十八烷酸随着巨大芽孢杆菌传代时间的延长含量显著降低,说明 细胞生长消耗更多的脂肪酸生成细胞膜磷脂, 因此游离脂肪 ^^著 减少。 此外多数氛基酸, 如脯氨酸和 4-羟基脯氨酸显著减少, 5-氧
,也说明传代过程 中巨大芽孢杆菌消耗大量 ^酸用来维持自身生长, 合成胞内蛋 白。
以混菌细胞在传代时间为 0、 50、 100和 150天时的小分子代谢 物的相对含量为样本矩阵进行主成分分析(图 28 ),得分图(图 28-1 ) 显示 0代与 50、 100和 150代的混菌样本明显区分, 说明混菌传代培 养过程中, 由于两菌的相互作用, 其传代进化的菌株体系与原始出 发菌体系明显不同, 但 50代和 100代较为接近, 在第一主成分上不 能明显区分。 图 29为区分不同传代时间混菌小分子代谢物标志物相 对含量的变化趋势图。 在这些标志物中, 多数氛基酸如脯氨酸、 甘 氨酸、 4-羟基脯氨酸、 5-氧脯氨酸和谷氛酰胺等随着传代时间的延 长含量成降低趋势, 尤其 Ut氨酸和 5-#Λ氨酸在 150代混菌中浓 度达到最低, 这两种物质是影响混菌发酵 2-酮古龙酸产量的关键物 质。 这些变化表明, 随着混菌传代增加, 两菌相互作用更加协调, 有助于目的产物的生成。
实施例 6-2
一种分析维生素 C生产菌株传代过程中小分子代谢物变化的方 法, 包括如下步骤:
( 1 )混菌传代培养:
①固体培养:
于液氮的 10 保藏于体积浓度为 15%的甘油水溶液中的 氧化葡糖杆菌 ( Gluconobacter oxydans )和 10 保藏于体积浓度 为 15%的甘油水溶液中的巨大芽孢杆菌 (Bacillus megaterium)分别 接种于固体培养基上, 培养 48 h;
②种子培养:
将经步骤(1 )①培养的巨大芽孢杆菌和氧化葡糖杆菌分别转 入种子培养基, 在 28 , 200 rpm摇床振荡培养 48 h, 分别得到巨 大芽孢杆菌种子液和氧化葡糖杆菌种子液;
将巨大芽孢杆菌和氧化葡糖杆菌接种到一个新的种子培养基 中,使巨大芽孢杆菌的密度为 2xl07CFU/mL,使氧化葡糖杆菌的密 度为 2xl08CFU/mL, 在 28*Ό, 200rpm摇床振荡培养, 以 48h为传代 周期, 以体积比为 1%为传代比接入新的种子培养基中, 传代 100天 得到混菌细胞, 在传代 0-100天选定 3个时间取样, 取 3样, 分别为 0 天、 50天、 100天;
③分纯:
将步骤( 1 )②获得的 3样的混菌细胞划线分纯后再分别接种于 固体培养基上, 28 培养 48 h;再分别转入新的种子培养基,在 28 , 200 rpm摇床振荡培养 48 h, 分别得到进化了的巨大芽孢杆菌种子 液和氧化葡糖杆菌种子液; 保藏于体积浓度为 15%的甘油水溶液 中;
④发酵:
将步骤(1 )③获得的进化了的巨大芽孢杆菌和氧化葡糖杆菌 以及将两种菌混合在一起的混合菌, 分别接种到新的种子培养基 中,使进化了的巨大芽孢杆菌的密度为 2xl07CFU/mL,进化了的氧 化葡糖杆菌的密度为 2xl08CFU/mL, 在 28*Ό, 200rpm摇床振荡培 养 15 h;
( 2 )胞内小分子代谢物样品的制备和测定:
①各取在步骤( 1 )④获得的三种细胞悬液 100 mL,分别在 1000 rpm离心 10 min, 去除上清液, 保留细胞, 用 pH=7.2的磷酸盐緩冲 液洗细胞 1次, 相同条件离心, 去除上清, 得到细胞;
②将步骤(2 )①所得细胞用液氮研磨细胞的方法制成干粉, 各称取 30 mg细胞干粉, 分别置于三个离心管中, 再加入 0.5mL提 取液, 加入 30μ 浓度为 0.020mg/mL氘标记的琥珀酸甲醇溶液为内 标物, 混匀; 1000 111离心10 111111, 取上清液置于三个新的离心管 中冷冻干燥;
③将步骤(2 )②获得三个离心管中分别加入 40 浓度为
10mg/mL的甲氧基胺盐酸盐的吡啶溶液于 30 水浴中肟化反应 60 min; 再加入 50μ Ν-甲基 -Ν-三甲^烷三氟乙酰胺于 35 水浴进 行硅烷化反应 30 min;
所述提取液为体积分数为 70%的甲醇水溶液;
④ GC-TOF/MS检测:
将 1 步骤( 2 )③获得的样品进到气相色 中, 色谱柱为 DB-5MS, 所述色镨柱的¾^为30 111 > 0.25 111111 1.(1., 进样口温度为 250 , 载气为高纯氦气, 恒压 80KPa, 分流比 3: 1, 柱温箱升温 程序为:初始 50*Ό,保持 3 min,以 4 /min的升到 260 ,保持 3 min, 使用 EI电离源, 源温 检测器电压 2300 V, 电离电压 60 eV, 电流 30 μΑ; 质傳检测范围 50-800 m/z; 小分子代谢物的鉴定使用 NIST 2005数据库, 质谱数据的处理和代谢物相对含量的测定使用 Masslynx 4.1软件; 并通过对色傳峰面积积分处理, 并与内标物的 峰面积对照, 得到小分子代谢物的相对含量;
( 3 )主成分分析:
①将步骤( 2 )④获得的维生素 C生产菌株传代过程的小分子代
谢物的相对含量数据进行 Pareto预处理;
②用 SIMCA-P 11.5软件对预处理后的数据进行主成分分析,得 到区分不同传代时间维生素 C生产菌株的小分子代谢物标志物; ( 4 )过程分析
将小分子代谢物标志物的含量按照不同传代时间制成图表,观 察并分析小分子代谢物标志物变化的规律, 检测出维生素 C生产菌 株传代过程中细胞内小分子代谢物的变化。
实施例 6-3
一种分析维生素 C生产菌株传代过程中小分子代谢物变化的方 法, 包括如下步骤:
( 1 )混菌传代培养:
①固体培养:
取存于液氮的 500 保藏于体积浓度为 30%的甘油水溶液中 的氧化葡糖杆菌( Gluconobacter oxydans )和 500 保藏于体积浓 度为 30%的甘油水溶液中的巨大芽孢杆菌 (Bacillus megaterium)分 别接种于固体培养基上, 培养 24;
②种子培养:
将经步骤(1 )①培养的巨大芽孢杆菌和氧化葡糖杆菌分别转 入种子培养基, 在 35 , 280 rpm摇床振荡培养 24, 分别得到巨大 芽孢杆菌种子液和氧化葡糖杆菌种子液;
将巨大芽孢杆菌和氧化葡糖杆菌接种到一个新的种子培养基 中, 使巨大芽孢杆菌的密度为 2xlOie CFU/mL, 使氧化葡糖杆菌的 密度为 2xlOu CFU/mL, 在 35*Ό, 280 rpm摇床振荡培养, 以 24h 为传代周期, 以体积比为 10%为传代比接入新的种子培养基中, 传 代 150天得到混菌细胞, 在传代 0-150天中选定 4个时间取样, 取 4个 样, 分别在第 0、 50、 100和第 150天取 4个样;
③分纯:
将步骤( 1 )②获得的 4个样的混菌细胞划线分纯后再分别接种 于固体培养基上, 35 培养 24 h; 再分别转入新的种子培养基, 在 35*Ό , 280 rpm摇床振荡培养 24 h, 分别得到进化了的巨大芽孢杆 菌种子液和氧化葡糖杆菌种子液;保藏于体积浓度为 30%的甘油水 溶液中;
④发酵:
将步骤(1 )③获得的进化了的巨大芽孢杆菌和氧化葡糖杆菌 以及将两种菌混合在一起的混合菌, 分别接种到新的种子培养基 中, 使进化了的巨大芽孢杆菌的密度为 2xl01Q CFU/mL, 进化了的 氧化葡糖杆菌的密度为 2xlOuCFU/mL, 在 35*Ό, 280rpm摇床振荡 培养 10;
( 2 )胞内小分子代谢物样品的制备和测定:
①各取在步骤( 1 )④获得的三种细胞悬液 200 mL,分别在 3000 rpm离心 3 min, 去除上清液, 保留细胞, 用 pH=7.4的磷酸盐緩冲 液洗细胞 3次, 相同^ ^离心, 去除上清, 得到细胞;
②将步骤(2 )①所得细胞用液氮研磨细胞的方法制成干粉, 各称取 60 mg细胞干粉, 分别置于三个离心管中, 再加入 1.5 mL提 取液, 加入 70μ 浓度为 0.060mg/mL氘标记的琥珀酸甲醇溶液为内 标物, 混匀; 3000 111离心3 111111, 取上清液置于三个新的离心管 中冷冻干燥;
③将步骤(2 )②获得三个离心管中分别加入 100 浓度为 30 mg/mL的甲氧基胺盐酸盐的吡啶溶液于 40 水浴中肟化反应 120 min;再加入 ΙΟΟμί Ν-甲基 -Ν-三甲^ 烷三氟乙酰胺于 40 水浴进 行硅烷化反应 60 min;
所述提取液为体积分数为 60%的甲醇水溶液;
④ GC-TOF/MS检测:
将 1 步骤( 2 )③获得的样品进到气相色 中, 色谱柱为 DB-5MS, 所述色镨柱的¾^为30 111 > 0.25 111111 1.(1., 进样口温度为 280 , 载气为高纯氦气, 恒压 100KPa, 分流比 20: 1, 柱温箱升 温程序为: 初始 80*Ό, 保持 6 min, 以 δ /πήη的升到 300*Ό, 保持 8 min, 使用 EI电离源, 源温 260*Ό, 检测器电压 2700V, 电离电压 80 eV, 电流 50 μΑ; 质傳检测范围 50-800 m/z; 小分子代谢物的鉴定 使用 NIST 2005数据库, 质谱数据的处理和代谢物相对含量的测定 使用 Masslynx 4.1软件; 并通过对色傳峰面积积分处理, 并与内标 物的峰面积对照, 得到小分子代谢物的相对含量;
( 3 )主成分分析:
①将步骤( 2 )④获得的维生素 C生产菌株传代过程的小分子代 谢物的相对含量数据进行 Pareto预处理;
②用 SIMCA-P 11.5软件对预处理后的数据进行主成分分析,得 到区分不同传代时间维生素 C生产菌株的小分子代谢物标志物;
( 4 )过程分析
将小分子代谢物标志物的含量按照不同传代时间制成图表,观 察并分析小分子代谢物标志物变化的规律, 检测出维生素 C生产菌 株传代过程中细胞内小分子代谢物的变化。
实验证明, 实施例 6-2和实施例 6-3与实施例 6-1的结果类似。 本发明所采用的固体培养基、种子培养基的组成选自中国专利 申请号为 201110314740.9公开的培养基, 例如:
固体培养基:按比例称取 L-山椠糖 20 g,玉米浆 3 g,牛肉骨 3 g, 酵母浸粉 3 g, 尿素 1 g,蛋白胨 10 g,琼脂 20 g, KH2P04 1 g, MgS04 0.2 g, CaC03 l g, 加水至 1 L, 调 pH=6.8, 1210C灭菌 20 min, 制 成固体培养基。
种子培养基:按比例称取 L-山椠糖 20 g,玉米浆 3 g,牛肉骨 3 g, 酵母浸粉 3 g, 尿素 l g, 蛋白膝 10 g, KH2P04 1 g, MgS04 0.2 g, CaC03 l g, 加水至 1 L, 调 pH=6.8, 121。C灭菌 20 min, 制成种子 培养基。
本发明所采用的菌株巨大芽孢杆菌 (Bacillus megaterium) CGMCC No 1.459和氧化葡糖杆菌 (Gluconobacter oxydans)
CGMCC No 1.110只用于说明本发明, 但并不用于限定本发明, 实 明, 巨大芽孢杆菌、 氧化葡糖杆菌的其它菌株也可以用于本发 明。 实施例 7
含有编码山椠酮脱氢酶基因载体的氧化葡糖杆菌在提高 2-酮 基 -L-古龙酸混菌发酵性能中的应用。 其特征是包括如下步骤:
( 1 ) 山椠酮脱氢酶基因的体外扩增:
采用细菌基因组提取试剂盒提取氧化葡糖杆菌的基因组;取该 基因组溶液 1μ1, 5xFastPfu buffer 4μ1, 20mM的 dNTP 2μ1, 20ηΜ 的引物 1 0.4μ1,20ηΜ的引物 2 0.4μ1,无菌水 11.8μ1, FastPfu酶 0.4μ1, 在 PCR管中混合均匀; 将 PCR管;^ PCR仪中进行扩增循环,扩增 程序为: 95。C 2min; 95°C 20s, 55°C 35s, 72 °C 2min, 共 25个循环; 72 °C 5min; 4。C 30min。 将 PCR产物进行琼脂糖凝胶电泳, 将 PCR 产物条带切下, 经琼脂糖凝胶回收试剂盒纯化 PCR扩增产物。
所述引物 1的序列为: 5,- CCCAAGCTTGACTGGCAGCAGCGCAAC-3'
所述引物 2的序列为: 5,-
CGCGGATCCCCGTGATAGCGGCACATGTC-3'
( 2 )编码山椠酮脱氢酶基因载体的构建:
取步骤(1 )获得的 PCR扩增产物溶液 8μ1, 与 Ιμΐ lOxdigest buffer, 0.5μ1 Hindlll酶, 0.5μ1 BamHI酶混合均匀, 在 37。C^^下 进行酶切反应 2小时; 反应后产物进行琼脂糖凝胶电泳, 将酶切产 物条带切下, 经琼脂糖凝胶回收试剂盒纯化酶切 PCR产物。取载体 pBBRlMCS溶液 8μ1, 与 Ιμΐ lOxdigest buffer, 0·5μ1 ΚρηΙ酶, 0.5μ1 Hindlll酶混合均匀, 在 37eC 下进行酶切反应 2小时; 反应后产 物进行琼脂糖凝胶电泳, 将酶切产物条带切下, 经琼脂糖凝胶回收 试剂盒纯化酶切载体产物。 取酶切 PCR产物 5.5μ1, 酶切载体产物 3μ1, lOxligase buffer 1μ1, DNA ligase 0.5μ1, 混合均匀, 在 22。C条 件下进行连接反应 30min。 将连接产物用化学转化法转化入大肠杆 菌 DH5(x中, 涂布于含抗生素的 LB固体培养基上, 在 37。C 下培 养 12h。 培养后获得的单菌落在 LB液体培养基中 37。C培养 12h, 用 质粒小量提取试剂盒提取质粒, 获得编码山椠酮脱氢酶基因载体。
( 3 )编码山椠酮脱氢酶基因载体转化入氧化葡糖杆菌
将氧化葡糖杆菌涂布在固体培养基上,在 30。C 下培养 48小 时;用 2ml无菌水将菌体洗下,水浴 10min, 4。C, 4000rpm离心 5min 后收集细胞, 用预冷的无菌水洗一次, 10%甘油洗两次后, ΙΟΟμΙ 10%甘油重悬细胞; 与步骤(2 )所得编码山椠酮脱氢酶基因载体 的水溶液 ΙΟμΙ混合均匀置于电转杯中, 冰浴 5min, 将电转杯置于电 转仪中 1800V电击;电击产物与 900μ1种子培养基混合均匀,在 30。C, 140rpm 下培养 2小时, 将培养物涂布于固体培养基上, 在 30。C 条件下培养 4天,获得的单菌落转入种子培养基中,在 30。C, 250rpm 条件下培养, 获得含有编码山椠酮脱氢酶基因载体的氧化葡糖杆 菌。
所述固体培养基为: L-山椠糖 20g, 玉米浆 3g, 牛肉骨 3g, 酵 母浸粉 3g, 尿素 lg,蛋白胨 10g,琼脂 20g, KH2P04lg, MgSO40.2g,
CaC03lg, 加水至 1L, 调 pH为 6.8, 121。C灭菌 20min。
所述种子培养基为: L-山椠糖 20g, 玉米浆 3g, 牛肉骨 3g, 酵 母浸粉 3g, 尿素 lg,蛋白胨 10g, KH2P04lg, MgSO40.2g, CaC03lg, 加水至 1L, 调 pH为 6.8, 121。C灭菌 20min。
( 4 )混菌发酵
将步骤(3 )获得的含有编码山椠酮脱氢酶基因载体的氧化葡 糖杆菌和巨大芽孢杆菌接种到发酵培养基中,使含有编码山椠酮脱 氢酶基因载体的氧化葡糖杆菌的密度为 4xl08cfu/ml , 使巨大芽孢 杆菌的密度为 4xl08 cfu/ml, 在 30。C, 250rpm条件下培养 120h, 获 得 2-酮基 -L-古龙酸。
所述发酵培养基为: 按比例称取 L-山椠糖 80g, 玉米浆 20g, 尿 素 12g, KH2P04lg, MgSO40.5g, CaC03lg, 加水至 1L, 调 pH为 7.0, 121。C灭菌 20min。
2-酮基 -L-古龙酸和 L-山椠糖含量测定:
采用高效液相色谱法( HPLC ) 。
样品制备: 取发酵培养不同时间的发酵液 lmL于 1.5mL离心管 中, 10000r/min转速离心 3min,取上清 ΙΟΟμ 于 1.5mL离心管中, 并 加入 900μΙ^^动相(5mM H2S04 )得到稀幹十倍的样品。 振荡混匀 后, 用 0.22μπι的纤维素微孔滤膜过滤样品, 得到待测样品。
高效液相色镨条件: 色镨柱: bio-rad HPX-87H,流动相: 5mM H2S04, 流速: 0.6mL/min, 柱温: 65。C, 示差检测器。
实施例 7-1检测结果见图 30。
图例: ◊: 原始氧化葡糖杆菌和巨大芽孢杆菌混菌发酵; △:含有编码山椠酮脱氢酶基因载体的氧化葡糖杆菌和巨大芽 孢杆菌混菌发酵。
原始氧化葡糖杆菌与巨大芽孢杆菌利用实施例 7-1步骤( 2 )的
发酵条件进行搭配混菌发酵的 2-酮基 -L-古龙酸产率达到 87%;用实 施例 7-1的方法获得的含有编码山椠酮脱氢酶基因载体的氧化葡糖 杆菌和巨大芽孢杆菌混菌发酵的 2-酮基 -L-古龙酸产率达到 98%; 2- 酮基 -L-古龙酸产率提高了 12.6%。 实施例 8-1
一种检测谷胱甘肽作用于氧化葡糖杆菌过程中细胞内蛋白质 变化的方法, 其特征是包括如下步骤:
( 1 )细胞内蛋白质的测定:
①细胞收集及淬灭:
取 3份氧化葡糖杆菌以 8 %的体积比分别接种到发酵培养基 A 中, 另取 3份所述氧化葡糖杆菌以 8%的体积比分别接种到发酵培养 基 B中, 将两种接种后的培养基在 28。C, 转速为 200rpm条件下培养 发酵,在发酵过程中选取 1 h、 15 h为^ 点取出发酵液样品,在 4。C 下, 以 4000rpm的转速离心, 收集下层的细胞, 并用 pH为 7.2的磷 酸盐緩冲液清洗, 立即用液氮淬灭, 终止代谢反应; 用液氮研磨用 于破碎细胞, 获得 3份从培养基 A中发酵 1 h收集淬灭的破碎细胞, 3 份从培养基 A中发酵 15 h收集淬灭的破碎细胞, 3份从培养基 B中发 酵 lh收集淬灭的破碎细胞, 3份从培养基 B中发酵 15h收集淬灭的破 碎细胞;
所述发酵培养基 A为: SO g.L-1 山椠糖 O g.L 1 玉米浆, 1 g*L 1 KH2P04, 0.2 g*L 1 MgS04,^12 g*L 1尿素, 余量为水;
所 i L酵培养基 B为: 80 1 山椠糖 O g'L 1 玉米浆, 1 g-L 1 KH2P04, 0.2 g-L 1 MgS04, and 12 g*L 1尿素, 0.8~1.5mg*mL 1 的谷胱甘肽, 余量为水;
②提取细胞内蛋白:
取步骤①获得的破碎细胞, 每份 lOOmg 分别置于离心管中, 每管加入 0.5ml细胞裂解液,混匀,冰上间 声破碎 20s;加入 5μί 的质量比为 2:1的 DNase l /RNaseA酶混合溶液, 混匀, 4。C静置反 应 lOmin;加入 5μί 80mM的苯甲基磺酰氟异丙醇溶液, 4。C静置 lh; 15000rpm离心 25min;取上清,得到蛋白溶液。所述细胞裂解液为: 8 mol-L 1尿素,质量浓度为 4% 的 (3-[(3 -胆酰胺丙基) -二乙胺】 - 丙磺酸)(CHAPS ) , 40 mM 的 Tris, 余量为水;
③蛋白浓度测定:
采用 Bradford试剂盒,将牛血清蛋白由低浓度到高浓 入考 马斯亮蓝 G-250溶液中, 测定步骤②获得的各个蛋白溶¾^59511111 处的吸光值, 建立标准曲线; 测定各个蛋白溶液蛋白的浓度;
④沉淀蛋白
分别取包含 50μ8蛋白的步骤③获得的各个蛋白溶液, 加入 4倍 体积的 -20。C的丙酮, 沉淀 12h; 离心, 弃上清, 沉淀用 -20。C的体积 浓度为 70%的丙酮水溶液洗涤; 冷冻干燥备用; -80°C贮存;
⑤蛋白还原以及酶解
向步骤④中所得的各个干燥蛋白中,添加 ΙΟμί 40mM的三乙基 碳酸氢铵水溶液溶解蛋白;
加入 Ιμί三(2-羧乙基)膦, 在 50。C反应 lh, 对各个蛋白进行 还原化处理; 然后加入 l L甲基硫代磺酸甲酯, 室温反应 10min, 终止还原反应;
向上述溶液中, 加浓度为 0.2 g/ L的胰蛋白酶水溶液 30μί, 37°C反应 12小时, 进行蛋白酶解;
⑥蛋白标记
在每个经步骤⑤酶解的蛋白酶解液中分别加入一管用 60~80μί 乙醇溶解的 iTRAQ标记试剂, 室温反应 lh;
⑦溶液混合
将步骤溶液⑥获得的溶液混合得 3份混合液, 使每个混合液中 都包括从培养基 A中发酵 1 h收集淬灭的破碎细胞再经步骤② -⑥后 获得的标记蛋白、 从培养基 A中发酵 15 h收集淬灭的破碎细胞再经 步骤②-⑥后获得的标记蛋白、从培养基 B中发酵 1 h收集淬灭的破碎 细胞再经步骤② -⑥后获得的标记蛋白和从培养基 B中发酵 15 h收集 淬灭的破碎细胞再经步骤②-⑥后获得的标记蛋白; 于 -20。C保存;
⑧差异表达蛋白鉴定
将⑦中得到的混合液, 进行 Q-Tof质傳鉴定, 得到蛋白谱, 通 过定量得到各混合组样品的差异表达蛋白;
( 2 )主成分分析:
采用 matlab对步骤( 1 )⑧中得到的数据进行标准化后, 进行 主成分分析, 得到具有不同变化^ 的数据类别, 获得候选差异蛋 白;
( 3 )过程分析
将步骤(2 )获得的候选差异蛋白含量按照时间序列制成图表, 观察并分析这些蛋白变化的规律,进而发现谷胱甘肽在提高氧化葡 糖杆菌产 2-酮 -L-古龙酸过程中的作用。 添加谷胱甘肽后, 氧化葡糖杆菌发酵过程中, 胞内鉴定到的蛋 白如表 1所示。 氧化葡糖杆菌胞内蛋白
50S ribosomal protein L6 (BL10) invasion associated locus B (IalB) family protein
ribosomal protein S8 family protein single-stranded DNA-binding protein (SSB)
(Helix-destabilizingprotein)
2-deoxy-D-gluconate 3-dehydrogenase his Kinase A (phosphoacceptor) domain protein
ribosomal protein S14p/S29e family protein euoyl [acyl carrier proteiii] reductase
[NADH] 1 (NADH-dependent enoyl-ACP reductase 1)
50S ribosomal protein L5 (BL6) cold shock protein cspB (Major cold shock protein)
ribosomal protein L24 sorbose/sorbosone dehydrogenase ribosomal protein S17 family protein trigger factor
ribosomal protein L29 ribosomal protein L9
ribosomal protein S3 ribosomal protein S18
ribosomal protein L22 ribosomal protein S6
ribosomal protein S19 acyl carrier protein
ribosomal protein L2 pyruvate dehydrogenase El component subunit beta
ribosomal protein L23 family protein deoC/LacD family aldolase family protein
50S ribosomal protein L4 (BL4) cyclophilin type peptidyl-prolyl cis-trans isomerase/CLD family protein
ribosomal protein L3 family protein dihydrolipoyllysine-residue
double-strand break repair protein AddB bacterial extracellular solute-binding family protein
adenosylhomocysteinase glycine cleavage system H protein
chain D, Crystal Structure Of 6-phosphogluconolactonase
Uncharacterized Protein
branched-chain amino acid nucleoside diphosphate kinase family protein aminotransferase
hypothetical protein cytosol aminopeptidase family, catalytic domain protein
response regulator ribosomal protein S9/S16 family protein uncharacterized protein-like protein ribosomal protein L13
thiamin/thiamin pyrophosphate ABC NAD
transporter, thiamin/ thiamin
pyrophospate-binding protein
chorismate synthase NAD(P) (+) transhydrogenase (AB-specific), alpha subunit
DNA-binding protein HU 1 (DNA-binding cobaltochelatase, CobS subunit
protein II) (HB)
chaperone protein DnaJ NADPH-dependent FMN reductase family protein
chaperone protein DnaK acetyl-CoA carboxylase, biotin carboxyl carrier protein
ribosomal protein S15 acetyl-CoA carboxylase, biotin carboxylase
SI RNA binding domain protein ATP-dependent Clp protease, ATP-binding subunit ClpX
hypothetical protein clp protease family protein
D-isomer specific 2-hydroxyacid conserved hypothetical protein dehydrogenase, NAD binding domain
protein
NAD(P)H: q uinone oxidoreductase transaldolase, putative
phosphoserine aminotransferase DNA topoisomerase I
phosphogl cerate dehydrogenase histidine kinase-, DNA gyrase and
HSP90-like ATPase family protein
ATP-dependent chaperone ClpB peptidase T
resolvase, N terminal domain protein flavin reductase like domain protein antirestriction protein glucans biosynthesis protein G uncharacterized ABC transporter sorbose/sorbosone dehydrogenase ATP-binding protein yehX
AGR— L— 2804p, nitrilotriacetate conserved hypothetical protein monooxygenase component A homolog ytnJ - Bacillus subtilis
YKOF-related family protein oppF
glutathione S-transferase, C-terminal bacterial extracellular solute-binding domain protein proteins, family 5 Middle family protein binding-protein-dependent transport system H-NS histone family protein
inner membrane component family protein
glutathione synthase ribosomal protein S21
acetyl-CoA carboxylase, carboxyl N-6 DNA Methylase family protein transferase, beta subunit
ompA family protein ribosomal protein L27
nitrogen regulatory protein P-II 1 ribosomal protein L21
dihydrodipicolinate synthase large conductance mechanosensitive channel protein
aldo/keto reductase family protein conserved hypothetical protein
DNA-directed RNA polymerase, omega phenylalanyl-tRNA synthetase, beta subunit subunit
aldo/keto reductase family protein pyruvate carboxylase
riboflavin biosynthesis protein RibD phenylalanyl-tRNA synthetase, alpha
subunit
6,7-dimethyl-8-ribityllumazine synthase conserved hypothetical protein
aldo/keto reductase family protein ribosomal protein L20
periplasmic binding proteins and sugar hsp20/alpha crystallin family protein binding domain of the Lad family protein
putative non-heme chloroperoxidase phosphate ABC transporter, ATP-binding (Chlorideperoxidase) protein
ATPase hemolysin-type calcium-binding region carbamoyl-phosphate synthase large chain aminotransferase class IV family protein (Carbamoyl-phosphate synthetase ammonia
chain)
ribosomal protein SI translation initiation factor IF-1
integration host factor, beta subunit carboxynorspermidine decarboxylase ribosomal protein L25, Ctc-form phosphopyruvate hydratase
L-lactate dehydrogenase [cytochrome] N-acetyl-gamma-glutamyl-phosphate
reductase
membrane-bound aldehyde dehydrogenase phosphoribosylformylglycinamidine
[pyrroloquinoline-quinone] (ALDH) synthase II
glutamine synthetase, catalytic domain transketolase
Cold-shock DNA-binding domain protein conserved hypothetical protein lysyl-tRNA synthetase insulinase (Peptidase family Ml 6) family protein
urease, alpha subunit ahpC/TSA family protein
ribosomal protein S16 uroporphyrinogen decarboxylase urease accessory protein UreG ribosomal protein S4
putative lipoprotein 如图 31A所示,氧化葡糖杆菌在添加谷胱甘肽 15h后,蛋白表达 状况与空白对照有明显差异, 通过对具体差异进行分析, 得到一系 列生物标志物, 包括 素焦磷酸 /硫胺素转运蛋白 (thiB )、 硫胺 素转运蛋白 (TkoF ) 、 寡肽转运蛋白 ( bacterial extracellular solute-binding protein, family 5 )等。 谷胱甘肽作为一种三肽, 是 微生物体内含量最高的硫醇类物质,可以通过寡肽转运途径 ¾ 细 胞。谷胱甘肽氧化型与还原型谷胱甘肽的转化对于维持微生物的氧 化还原状态有重要作用, 此转化过程需要 NADPH参与, 磷酸戊糖 途径的提高可以间接利于维持氧化葡糖杆菌的氧化还原平衡状态, 使得其有较好的生长及产酸环境。 素焦磷酸, 是三羧酸循环中 丙酮酸脱氢酶、 酮戊二酸脱氢酶、磷酸戊糖途径中的转酮醇酶的重 要辅酶, 在中心碳代谢中发挥着重要作用。 通过主成分分析, 添加 谷胱甘肽后, 负责 素转运的两个蛋白均发生较大程度上调, 说 明谷胱甘肽的添加,使得细胞转运 素的能力提高。如图 32所示, 这两个硫胺素转运蛋白及丙酮酸脱氢酶、 酮戊二酸脱氢酶、 转酮醇 酶的表达量均在添加谷胱甘肽 15h后有明显提高。 同时, 通过对检 测到的蛋白进行定量分析, 发现添加谷胱甘肽 15h后, 氧化葡糖杆 菌三羧酸循环、 磷酸戊糖途径中的关键酶, 表达量均有上调, 如图
33所示, 可能与硫胺素焦磷酸转运增强有关。 说明氧化葡糖杆菌可 能存在硫胺素或硫胺素焦磷酸合成不足或者缺陷,这就为以后进行 分子生物学改造, 弥补这一缺陷, 提供了依据。
综上所述,谷胱甘肽对氧化葡糖杆菌生长及 2-酮 -L-古龙酸生产 有重^ f 用, 结合相关蛋白变化、 生长曲线及产酸情况, 说明谷胱 甘肽有利于促进氧化葡糖杆菌对硫胺素、硫胺素焦磷酸的转运, 从 而获得提高的三羧酸循环、 磷酸戊糖途径, 进一步获得还原力 NADPH, 为细胞调节胞内氧化还原状态提供能量。 这一发现, 为 后续对氧化葡糖杆菌进行基因改造提供了依据,也为工业混菌过程 研究及控制提供了基础。
实施例 8-2
一种检测谷胱甘肽作用于氧化葡糖杆菌过程中细胞内蛋白质 变化的方法, 包括如下步骤:
( 1 )细胞内的蛋白质进行测定:
①细胞收集及淬灭:
取 4份氧化葡糖杆菌以 10%的体积比分别接种到发酵培养基 A 中, 另取 4份所述氧化葡糖杆菌以 10%的体积比分别接种到发酵培 养基 B中, 将两种接种后的培养基在 30。C, 转速为 220rpm条件下培 养发酵, 在发酵过程中选取 l h、 15 h为^ 点取出发酵液样品, 在 4。C下, 以 5000rpm的转速离心, 收集下层的细胞, 并用 pH为 7.3的 磷酸盐緩冲液清洗, 用液氮淬灭, 终止代谢反应; 用液氮研磨用于 破碎细胞, 获得 4份从培养基 A中发酵 1 h收集淬灭的破碎细胞, 4份 从培养基 A中发酵 15 h收集淬灭的破碎细胞, 4份从培养基 B中发酵 lh收集淬灭的破碎细胞, 4份从培养基 B中发酵 15h收集淬灭的破碎 细胞; 发酵培养基 A和发酵培养基 B同实施例 8-1;
②提取细胞内蛋白:
取步骤①获得的破碎细胞, 每份 150mg 分别置于离心管中, 每管加入 lml细胞裂解液, 混匀, 冰上间歇超声破碎 40s; 加入 ΙΟμί 的质量比为 3:1的 DNase l /RNaseA酶混合溶液, 混匀, 4。C静置反 应 15min; 加入 12 L lOOmM的苯甲基磺酰氟异丙醇溶液, 4。C静置 2h; 15000rpm离心 30min; 取上清, 得到蛋白溶液; 所述细胞裂解 液同实施例 8-1;
③蛋白浓度测定:
采用 Bradford试剂盒,将牛血清蛋白由低浓度到高浓 入考 马斯亮蓝 G-250溶液中, 测定步骤②获得的各个蛋白溶¾^59511111 处的吸光值, 建立标准曲线; 测定各个蛋白溶液蛋白的浓度;
④沉淀蛋白
分别取包含 100 蛋白的步碌③获得的各个蛋白溶液, 加入 5 倍体积的 -30。C的丙酮, 沉淀 15h; 离心, 弃上清, 沉淀用 -30。C的体 积浓度为 80%的丙酮水溶液洗涤; 冷冻干燥备用; -80°C贮存;
⑤蛋白还原以及酶解
向步骤④所得的各个干燥蛋白中, 添加 2(^L50mM的三乙 酸氢铵水溶液溶解蛋白;
加入 2 L三(2-羧乙基)膦, 在 55。C反应 lh, 对各个蛋白进行 还原化处理; 然后加入 1.5 L甲^ ^代磺酸甲酯, 室温反应 12min, 终止还原反应;
向上述溶液中, 加浓度为 0.25μδ/μί的胰蛋白酶水溶液 25μί, 37°C反应 15小时, 进行蛋白酶解;
⑥蛋白标记
在每个经步骤⑤酶解的蛋白酶解液中分别加入一管用 70μί乙 醇溶解的 iTRAQ标记试剂, 室温反应 lh;
⑦溶液混合
将步骤溶液⑥获得的溶液混合得 4份混合液, 使每个混合液中 都包括从培养基 A中发酵 1 h收集淬灭的破碎细胞再经步骤② -⑥后 获得的标记蛋白、 从培养基 A中发酵 15 h收集淬灭的破碎细胞再经 步骤②-⑥后获得的标记蛋白、从培养基 B中发酵 1 h收集淬灭的破碎 细胞再经步骤② -⑥后获得的标记蛋白和从培养基 B中发酵 15 h收集 淬灭的破碎细胞再经步骤②-⑥后获得的标记蛋白; 于 -20。C保存;
⑧差异表达蛋白鉴定
将⑦中得到的混合液, 进行 Q-Tof质傳鉴定, 得到蛋白谱, 通 过定量得到各混合组样品的差异表达蛋白;
( 2 )主成分分析:
采用 matlab对步骤(1 )⑧中得到的数据进行标准化后, 进行 主成分分析, 得到具有不同变化^ 的数据类别, 获得候选差异蛋 白;
( 3 )过程分析
将步骤(2 )获得的候选差异蛋白含量按照时间序列制成图表, 观察并分析这些蛋白变化的规律,进而发现谷胱甘肽在提高氧化葡 糖杆菌产 2-酮 -L-古龙酸过程中的作用。
通过实验证明, 结果与实施例 8-1相似。
实施例 8-3
一种检测谷胱甘肽作用于氧化葡糖杆菌过程中细胞内蛋白质 变化的方法, 包括如下步骤:
①细胞收集及淬灭:
取 5份氧化葡糖杆菌以 16%的体积比分别接种到发酵培养基 A 中, 另取 5份所述氧化葡糖杆菌以 16%的体积比分别接种到发酵培 养基 B中, 将两种接种后的培养基在 32。C, 转速为 250rpm的条件下 培养发酵, 在发酵过程中选取 l h、 15 h为^ 点取出发酵液样品,
在 4。C下, 以 6000rpm的转速离心, 收集下层的细胞, 并用 pH为 7.4 的磷酸盐緩冲液清洗, 用液氮淬灭, 终止代谢反应; 用液氮研磨破 碎细胞, 获得 5份从培养基 A中发酵 1 h收集淬灭的破碎细胞, 5份从 培养基 A中发酵 15 h收集淬灭的破碎细胞, 5份从培养基 B中发酵 lh 收集淬灭的破碎细胞, 5份从培养基 B中发酵 15h收集淬灭的破碎细 胞; 发酵培养基 A和发酵培养基 B同实施例 8-1;
②提取细胞内蛋白:
取步骤①获得的破碎细胞, 每份 200mg 分别置于离心管中, 每管加入 2ml细胞裂解液, 混匀, 冰上间歇超声破碎 50s; 加入 15μί 的质量比为 4:1的 DNase l /RNaseA酶混合溶液, 混匀, 4。C静置反 应 30min; 加入 15 L120mM的苯甲基磺酰氟异丙醇溶液, 4。C静置 3h; 15000rpm离心 40min; 取上清, 得到蛋白溶液; 细胞裂解液同 实施例 8-1;
③蛋白浓度测定:
采用 Bradford试剂盒,将牛血清蛋白由低浓度到高浓 入考 马斯亮蓝 G-250溶液中, 测定步骤②获得的各个蛋白溶¾^59511111 处的吸光值, 建立标准曲线; 测定各个蛋白溶液蛋白的浓度;
④沉淀蛋白
分别取包含 150 蛋白的步碌③获得的各个蛋白溶液, 加入 6 倍体积的 -40。C的丙酮, 沉淀 20h; 离心, 弃上清, 沉淀用 -40。C的体 积浓度为 85%的丙酮水溶液洗涤; 冷冻干燥备用; -80°C贮存;
⑤蛋白还原以及酶解
向步骤④所得的各个干燥蛋白中, 添加 4(^L60mM的三乙 酸氢铵水溶液溶解蛋白;
加入 4 L三(2-羧乙基)膦, 在 60。C反应 lh, 对各个蛋白进行 还原化处理; 然后加入 2 L甲基硫代磺酸甲酯, 室温反应 15min,
终止还原反应;
向上述溶液中, 加浓度为 0.3 g/ L的胰蛋白酶水溶液 30μί, 37。C反应 18小时, 进行蛋白酶解;
⑥蛋白标记
在每个经步骤⑤酶解的蛋白酶解液中分别加入一管用 80μί乙 醇溶解的 iTRAQ标记试剂, 室温反应 lh;
⑦溶液混合
将步骤溶液⑥获得的溶液混合得 5份混合液, 使每个混合液中 都包括从培养基 A中发酵 1 h收集淬灭的破碎细胞再经步骤② -⑥后 获得的标记蛋白、 从培养基 A中发酵 15 h收集淬灭的破碎细胞再经 步骤②-⑥后获得的标记蛋白、从培养基 B中发酵 1 h收集淬灭的破碎 细胞再经步骤② -⑥后获得的标记蛋白和从培养基 B中发酵 15 h收集 淬灭的破碎细胞再经步骤②-⑥后获得的标记蛋白; 于 -20。C保存;
⑧差异表达蛋白鉴定
将⑦中得到的混合液, 进行 Q-Tof质傳鉴定, 得到蛋白谱, 通 过定量得到各混合组样品的差异表达蛋白;
( 2 )主成分分析:
采用 matlab对步骤( 1 )⑧中得到的数据进行标准化后, 进行 主成分分析, 得到具有不同变化^ 的数据类别, 获得候选差异蛋 白;
( 3 )过程分析
将步骤(2 )获得的候选差异蛋白含量按照时间序列制成图表, 观察并分析这些蛋白变化的规律,进而发现谷胱甘肽在提高氧化葡 糖杆菌产 2-酮 -L-古龙酸过程中的作用。
通过实验证明, 结果与实施例 8-1相似。
实施例 9-1
寻找发酵用原料玉米浆的质量控制指标的方法, 包括下述步
( 1 )对 11批不同的玉米浆进行化学成分测定:
①样品的制备:
将 lg均匀的玉米浆样品置于离心管中, 离心收集上清; 将获得 的上清液用超纯水稀释 20倍,取 20μ 置于另一离心管中,加入 30μί 的 0.040mg/mL氘标记的琥珀酸甲醇溶液为内标。 冷冻干燥后, 加 入 50μί浓度为 20mg/mL甲氧基胺盐酸盐的吡啶溶于 30。C水浴中 肟化反应 90min。 反应结束后再加入 80μίΝ-甲基 -Ν-三甲基娃烷三 氟乙酰胺于 37。C水浴进行硅烷化反应 30miii;
② 气相色傳 -飞行时间质傳联用仪测定方法:
将 Ιμΐ步骤①获得的样品进到气相色谱中, 色傳柱为 DB-5MS , 所述色傳柱的规格为 30 mx0.25 mm i.d., 进样口温度 250。C, 载气 为高纯氦气, 流速 0.6ml/min, 分流比 20: 1, 柱温箱升温程序为: 初始 70。C保持 2min, 以 5。C/min的速度升到 290。C, 保持 10min, 使 用 EI电离源, 源温 280°C, 检测器电压 2500V, 电离电压 80eV, 电 流 50μΑ; 质傳检测范围 50-800m/z; 成分的鉴定使用 NIST数据库, 质傳数据的处理和成分相对含量的测定使用 Masslynx 4.1软件; 并 通过对色傳峰面积积分处理, 并与内标物的峰面积对照, 得到发酵 用原料玉米浆中成分的相对含量; 一共检测到 80多种化合物, 其中 能鉴定到 58种, 见表 1。
( 2 )偏最小二乘法判别分析:
①将步骤(1 )获得的数据进行标准化和 Pareto预处理, 以消 除同一样品中不同成分含量的较大差异对偏最小二乘判别分析结 果的影响。
②用 SIMCA-P 11.5软件对预处理后的数据进行偏最小二乘判 别分析,得到用于表达样本相似性和差异性的得分图、载荷图和 VIP 图; 在得分图中, 样品点相互之间距离越近, 说明样本的相似 大, 距离越远, 说明样本差异越大, 可用来寻找不同批次玉米浆中 各物质的相似和差异; 在载荷图中, 每个点表示每个物质, 距离中 心点距离越远的物质, 其在不同批次的含量差异越大, 便可作为玉 米浆的质量控制指标; VIP表示每个物质的对区分样本的贡献大小, VIP>1可以认为是对玉米浆的质量影响最为显著的指标。
从图 34-1(不同批次玉米浆主成分分析 t[l】-t[2】图)中可以得到: 11批玉米浆可以被明显区分为三类, 即批次 1和 2聚在一起, 批次 3、 4和 11聚在一起, 其余批次聚为一类。 由图 34-2 (不同批次玉米浆 主成分分析 t[l】-u[l】图)可知, 批次 1和 2的 u[l】值最大, 批次 3、 4 和 11的 u[l】值最小, 其余批次的 u[l】值在原点附近, 由此分为三类。 这就表明即使玉米浆检测符合现行的质量检查,但不同批次的玉米 浆依然存在较大的差异, 对发酵有较大的影响。
从图 35中可以找到区分不同批次玉米浆的质量的物质, 在图 32-1 (不同批次玉米浆 w*c[l卜 w*c[2】散点图)根据距离中心点越远, 物质的含量差异越大的原则,可以初步筛选不同批次玉米浆含量差 异较大的物质;在图 32-2(不同批次玉米浆第一主成分的 p-p(corr) S 图)根据 I corr I .>0.5的原则, 进一步筛选可以区分不同批次玉米 浆的物质, p ( corr ) >0.5表明该物质对图 34中聚类正半轴影响较大, p ( corr ) < -0.5表明该物质对图 34中聚类负半轴影响较大; 根据图 33来确定各物质的贡献大小, VIP值越大表示各物质对聚类分析的 贡献也越大,一般以 VIP>1为原则选择标志物。综合三张图的分析, 从而最终可以确定区别不同批次玉米浆质量的主要物质有 16个,依 次为葡萄糖、 乳酸、 脯氨酸、 磷酸、 半乳糖、 丙氨酸、 果糖、 5-酮
脯氨酸、甘氨酸、 天冬氛酸、 纈氨酸、 苯丙氨酸、丝氨酸、柠檬酸、 谷氨酸和赖氨酸。 进一步分析发现, 乳酸和磷酸含量差异主要由玉 米浸渍中微生物发酵引起的, 是不同厂家玉米浆工艺差异而造成 使用的玉米产地或季节不同而造成的;这些质量 异标志 要 为微生物提供营养物质的, 另外脯氨酸和甘氨酸在发酵过程中还对 微生物的渗透压具有重要影响。 由于前九个物质影响尤为显著, 因 此可以考虑作为玉米浆的质量控制指标。
表 9-1: 实施例 9- 1 所测得的玉米浆中的化学成分的种类
16 苏氨酸 16.27 45 甘露醇 29.29
17 胸腺嘧啶 16.62 46 酪氛酸 29.37
18 β-丙氨酸 17.37 47 阿卓糖 30.24
19 苹果酸 19.03 48 葡萄糖酸 30.77
20 4-羟基-脯氨酸 19.28 49 黄嘌呤 30.96
21 赤藓糖醇 19.52 50 塔洛糖 31.22
22 甲硫氛酸 19.69 51 十六烷酸 31.63
23 5-鲷脯氨酸 19.72 52 肌醇 32.36
24 天冬氛酸 19.83 53 鸟嘌呤 33.08
25 丁酸 20.02 54 33.17
26 半胱氛酸 17.37 55 葡萄糖醇 34.63
27 辛酸 21.31 56 酸 35.37
28 22.32 57 尿苷 38.81
29 苯丙氨酸 22.36 58 鸟苷 43.95 实施例 9-2
寻找发酵用原料玉米浆的质量控制指标的方法, 包括下述步 ( 1 )对 11批不同的玉米浆进行化学成分测定:
①样品的制备:
将 2g均匀的玉米浆样品置于离心管中, 离心收集上清; 将获得 的上清液用超纯水稀幹 40倍,取 20μ 置于另一离心管中,加入 40μί 的 0.040mg/mL氘标记的琥珀酸甲醇溶液为内标。 冷冻干燥后, 加 入 50μί 20mg/mL的甲氧基胺盐酸盐的吡啶溶于 35。C水浴中肟化反 应 120min。 反应结束后再加入 70μίΝ-甲基 -Ν-三甲^ 烷三氟乙酰 胺于 35°C水浴, 进行硅烷化反应 50min;
② 气相色傳 -飞行时间质傳联用仪测定方法:
将 Ιμΐ步骤①获得的样品进到气相色谱中, 色谱柱为 DB-5MS, 所述色傳柱的规格为 30 mx0.25 mm i.d., 进样口温度 280。C, 载气 为高纯氦气, 流速 0.6ml/min, 分流比 30: 1, 柱温箱升温程序为: 初始 80。C保持 5 min, 以 8。C/min的速度升到 300。C, 保持 8min, 使 用 EI电离源, 源温 260°C, 检测器电压 2700V, 电离电压 80eV, 电 流 50μΑ; 质傳检测范围 50-800m/z; 成分的鉴定使用 NIST数据库, 质傳数据的处理和成分相对含量的测定使用 Masslynx 4.1软件; 并 通过对色傳峰面积积分处理, 并与内标物的峰面积对照, 得到发酵 用原料玉米浆中成分的相对含量。
( 2 )偏最小二乘判别分析:
①将步骤(1 )获得的数据进行标准化和 Pareto预处理, 以消 除同一样品中不同成分含量的较大差异对偏最小二乘判别分析结 果的影响。
②用 SIMCA-P 11.5软件对预处理后的数据进行偏最小二乘判 别分析,得到用于表达样本相似性和差异性的得分图、载荷图和 VIP 图; 在得分图中, 样品点相互之间距离越近, 说明样本的相似 大, 距离越远, 说明样本差异越大, 可用来寻找不同批次玉米浆中 各物质的相似和差异; 在载荷图中, 每个点表示每个物质, 距离中 心点距离越远的物质, 其在不同批次的含量差异越大, 便可作为玉 米浆的质量控制指标; VIP表示每个物质的对区分样本的贡献大小, VIP>1可以认为是对玉米浆质量影响最为显著的指标。
通过实验证明, 本实施例的方法也可以得到与实施例 9-1相似 的结果。
实施例 9-3
寻找发酵用原料玉米浆的质量控制指标的方法, 包括下述步
( 1 )对 11批不同的玉米浆进行化学成分测定:
①样品的制备:
将 0.5g均匀的玉米浆样品置于离心管中, 离心收集上清; 将获 得的上清液用超纯 7j #20倍, 取 40μί置于另一离心管中, 加入 30μί的 0.040mg/mL氘标记的琥珀酸甲醇溶液为内标。冷冻干燥后, 加入 70μί 浓度为 20mg/mL的甲氧基胺盐酸盐的吡啶溶于 37。C水 浴中肟化反应 60min。 反应结束后再加入 ΙΟΟμίΝ-甲基 -Ν-三甲^^ 烷三氟乙酰胺于 40。C水浴, 进行硅烷化反应 20min;
② 气相色傳 -飞行时间质傳联用仪测定方法:
将 Ιμΐ步骤①获得的样品进到气相色谱中, 色谱柱为 DB-5MS, 所述色傳柱的规格为 30 mx0.25 mm i.d., 进样口温度 270。C, 载气 为高纯氦气, 流速 0.7ml/min, 分流比 20: 1, 柱温箱升温程序为: 初始 70。C保持 3min, 以 4。C/min的速度升到 290。C, 保持 10min, 使 用 EI电离源, 源温 280°C, 检测器电压 2500V, 电离电压 70eV, 电 流 40μΑ; 质傳检测范围 50-800m/z; 成分的鉴定使用 NIST数据库, 质傳数据的处理和成分相对含量的测定使用 Masslynx 4.1软件; 并 通过对色傳峰面积积分处理, 并与内标物的峰面积对照, 得到发酵 用原料玉米浆中成分的相对含量。
( 2 )偏最小二乘判别分析:
①将步骤(1 ) 的数据进行标准化和 Pareto预处理, 以消除同 一样品中不同成分含量的较大差异对偏最小二乘判别分析结果的 影响。
②用 SIMCA-P 11.5软件对预处理后的数据进行偏最小二乘判 别分析,得到用于表达样^目似性和差异性的得分图、载荷图和 VIP 图; 在得分图中, 样品点相互之间距离越近, 说明样本的相似
大, 距离越远, 说明样本差异越大, 可用来寻找不同批次玉米浆中 各物质的相似和差异; 在载荷图中, 每个点表示每个物质, 距离中 心点距离越远的物质, 其在不同批次的含量差异越大, 便可作为玉 米浆的质量控制指标; VIP表示每个物质的对区分样本的贡献大小, VIP>1可以认为是对玉米浆质量影响最为显著的指标。
通过实验证明, 本实施例的方法也可以得到与实施例 9-1相似 的结果。
本发明所采用的菌株巨大芽孢杆菌 (Bacillus megaterium) CGMCC No 1.459和氧化葡糖杆菌 (Gluconobacter oxydans)
CGMCC No 1.110只用于说明本发明, 但并不用于限定本发明, 实 明, 巨大芽孢杆菌、 氧化葡糖杆菌的其它菌株也可以用于本发 明。
尽管本发明的具体实施方式已经得到详细的描述, 本领域技 术人员将会理解。 根据已经公开的所有教导, 可以对那些细节进 行各种修改和替换, 这些改变均在本发明的保护范围之内。 本发 明的全部范围由所附权利要求及其任何等同物给出。
Claims
1. 混菌进化传代培养提高 2-酮基 -L-古龙酸产量的方法, 其特征是 包括如下步骤:
( 1 ) 固体培养:
取 10-500 μ L保藏于体积浓度为 15-30%的甘油水溶液中的氧化葡 糖杆菌( Gluconobacter oxydans )和 10-500 μ L保藏于体积浓度为 15-30%的甘油水溶液中的巨大芽孢杆菌 (Bacillus megaterium)分别 接种于固体培养基上, 28-35 培养 24-48小时;
( 2 )种子培养:
将经步骤(1 )培养的巨大芽孢杆菌和氧化葡糖杆菌分别转入种子 培养基, 在 28-35*Ό, 200-280 r/min摇床振荡培养, 24h-48h, 得到 巨大芽孢杆菌种子液和氧化葡糖杆菌种子液;
将巨大芽孢杆菌和氧化葡糖杆菌接种到新的种子培养基中,使巨大 芽孢杆菌的密度为 2 107-2 1010 cfu/ml ,使氧化葡糖杆菌的密度 为 2 X 108-2 1011 cfu/ml,在 28-35 , 200-280 r/min摇床振荡培养, 以 24h-48h为传代周期, 以体积比为 1%-10%为传代比接入新的种 子培养基中, 传代 50-80天;
( 3 )分纯:
将步骤(2 )获得的传代培养混菌菌株划线分纯, 再分别接种于固 体培养基上, 28-35 培养 24-48小时; 再分别转入种子培养基, 在 28-35*Ό , 200-280 r/min摇床振荡培养 24h-48h,得到进化了的巨大 芽孢杆菌种子液和进化了的氧化葡糖杆菌种子液;
( 4 )发酵:
将所述原始巨大芽孢杆菌和进化了的氧化葡糖杆菌接种到发酵培 养基中, 使原始巨大芽孢杆菌的密度为 2 107-2 1010 cfu/ml , 使 进化了的氧化葡糖杆菌的密度为 2 107-2 109 cfu/ml,在 28-35 , 200-280 r/min摇床振荡培养 72h-96h, 获得 2-酮基 -L-古龙酸。
2.一种强化两菌相互作用提高 2-酮基 -L-古龙酸产量的方法, 其特征是包括如下步骤:
( 1 ) 固体培养:
取 10-500 保藏于体积浓度为 15-30%的甘油水溶液中的 氧化葡糖杆菌 ( Gluconobacter oxydans )和 10-500 μ L保藏于体 积浓度为 15-30%的甘油水溶液中的巨大芽孢杆菌(Bacillus megaterium)分别接种于固体培养基上, 28-35 , 培养 24-48 小 时;
( 2 )种子培养:
将经步骤( 1 )培养的巨大芽孢杆菌和氧化葡糖杆菌分别转入 种子培养基,在 28-35 , 200-280 r/min摇床振荡培养, 24h-48h, 得到巨大芽孢杆菌种子液和氧化葡糖杆菌种子液;
将巨大芽孢杆菌和氧化葡糖杆菌接种到新的种子培养基中, 使巨大芽孢杆菌的密度为 2 107-2 1010 cfu/ml , 使氧化葡糖杆 菌的密度为 2 108-2 1011 cfu/ml, 在 28-35*Ό, 200-280 r/min摇 床振荡培养, 以 24h-48h为传代周期, 以体积比为 1%-10%为传 代比接入新的种子培养基中, 传代 100-200天;
( 3 )分纯:
将步骤( 2 )获得的传代培养混菌菌株划线分纯, 再分别接种 于固体培养基上, 28-35 培养 24-48小时; 再分别转入种子培养 基, 在 28-35*Ό, 200-280 r/min摇床振荡培养 24h-48h, 得到进化 了的巨大芽孢杆菌种子液和进化了的氧化葡糖杆菌种子液;
( 4 )发酵: 将所述进化了的巨大芽孢杆菌和进化了的氧化葡糖杆菌接种 到发酵培养基中, 使进化了的巨大芽孢杆菌的密度为 2 x l07-2 x 1010 cfu/ml , 使进化了的氧化葡糖杆菌的密度为 2 X 108-2 X 1011 cfu/ml, 在 28-35 , 200-280 r/min摇床振荡培养 72h-96h, 获得 2-酮基 -L-古龙酸或将所述原始巨大芽孢杆菌和进化了的氧化葡 糖杆菌接种到发酵培养基中, 使原始巨大芽孢杆菌的密度为 2 x 107-2 1010 cfu/ml , 使进化了的氧化葡糖杆菌的密度为 2 x 107-2 109 cfu/ml, 在 28-35 , 200-280 r/min摇床振荡培养 72h-96h, 获得 2-酮基 -L-古龙酸。
3. 权利要求 1或 2的方法,其特征是所述固体培养基的制备 为: 按比例称取 L-山椠糖 10-50g, 玉米浆 2-10g, 牛肉骨 2-10g, 酵母浸粉 2-10g, 尿素 0.5-5g, 蛋白胨 2-12g, 琼脂 10-50g, KH2PO40.5-5g, MgSO40.1-0.7g, CaCO30.5-5g, 加水至 1L, 调 pH为 6.5-7.0, 121 灭菌 20min, 制成固体培养基; 更优选地, 所述固体培养基的制备为:按比例称取 L-山椠糖 20g,玉米浆 3g, 牛肉骨 3g, 酵母浸粉 3g, 尿素 lg, 蛋白胨 10g, 琼脂 20g, KH2P04lg, MgSO40.2g, CaC03lg, 加水至 1L, 调 pH为 6.8, 121 灭菌 20min, 制成固体培养基; 优选地, 所述种子培养基制 备为:按比例称取 L-山椠糖 10-50g,玉米浆 2-10g,牛肉骨 2-10g, 酵母浸粉 2-10g, 尿素 0.5-5g, 蛋白胨 2-12g, KH2PO40.5-5g, MgSO40.1-0.7g, CaCO30.5-5g,加水至 1L,调 pH为 6.5-7.0, 121 *Ό 灭菌 20min, 制成种子培养基; 更优选地, 所述种子培养基制备 为: 按比例称取 L-山椠糖 20g, 玉米浆 3g, 牛肉骨 3g, 酵母浸粉 3g, 尿素 lg, 蛋白胨 10g, KH2P04lg, MgSO40.2g, CaC03lg, 加水至 1L, 调 pH为 6.8, 121 灭菌 20min, 制成种子培养基; 优选地, 所述发酵培养基制备为: 按比例称取 L-山椠糖 40-120g, 玉米浆 10-50g, 尿素 10-25g, KH2PO40.5-3g, MgSO40.2-1.2g, CaCO30.5-5g加水至 1L, 调 pH 为 6.5 -7.5, 121 *C灭菌 20min, 制成发酵培养基; 更优选地, 所述发酵培养基制备为: 按比例称 取 L-山椠糖 80g,玉米浆 20g,尿素 12g, KH2P04lg, MgSO40.5g, CaC03lg, 加水至 1L, 调 pH为 7.0, 121 *C灭菌 20min, 制成发 酵培养基。
4. 一种检测维生素 C 工业混菌传代不同代数蛋白质变化的 方法, 其特征是包括如下步骤:
( 1 )混菌传代培养:
①固体培养:
取存于液氮的 10-200 μ L保藏于体积浓度为 15-30%的甘油 水溶液中的氧化葡糖杆菌 ( Gluconobacter oxydans )和 10-200 μ L 保藏于体积浓度为 15-30%的甘油水溶液中的巨大芽孢杆菌 (Bacillus megaterium)分别接种于固体培养基上, 28-35 *€, 培养 24-48小时;
②种子培养:
将经步骤( 1 )①培养的巨大芽孢杆菌和氧化葡糖杆菌分别转 入种子培养基,在 28-35 , 200-280 r/min摇床振荡培养 24h-48h, 得到巨大芽孢杆菌种子液和氧化葡糖杆菌种子液;
将巨大芽孢杆菌和氧化葡糖杆菌接种到新的种子培养基中, 使巨大芽孢杆菌的密度为 2 107-2 1010 CFU/mL,使氧化葡糖杆 菌的密度为 2 108-2 1011 CFU/mL , 在 28-35 , 200-280 r/min 摇床振荡培养, 以 24h-48h为传代周期, 以体积比为 1 %-10%为 传代比接入新的种子培养基中, 传代 100-150天, 选定 3-4个取 样时间取 3-4个样;
③分纯:
将步骤( 1 )②获得的 3-4个样的混菌细胞划线分纯, 再分别 接种于固体培养基上, 28-35 培养 24 h-48 h; 再分别转入种子 培养基, 在 28-35 , 200-280 rpm摇床振荡培养 24 h-48 h, 得 到进化了的巨大芽孢杆菌种子液和进化了的氧化葡糖杆菌种子 液; 保藏于体积浓度为 15-30%的甘油水溶液中;
④不同进化时期巨大芽孢杆菌和氧化葡糖杆菌培养:
将步骤( 1 )③获得的进化了的巨大芽孢杆菌和进化了的氧化 葡糖杆菌分别接种到种子培养基中, 使进化了的巨大芽孢杆菌的 密度为 2 X 107-2 X 101β CFU/mL , 进化了的氧化葡糖杆菌的密度 为 2 X 108-2 10nCFU/mL, 在 28-35 , 200-280 r/min摇床振荡 培养 10-15h;
( 2 ) 细胞内蛋白质的测定:
①细胞收集及淬灭:
分别将步骤( 1 )④获得的巨大芽孢杆菌培养物和氧化葡糖杆 菌培养物, 在 下, 以 4000~6000rpm的转速离心, 收集下层 的细胞, 并用 pH为 7.2~7.4的磷酸盐緩冲液清洗, 用液氮淬灭, 终止代谢反应; 用液氮研磨破碎细胞;
②提取细胞内蛋白:
取所述破碎细胞, 每份 80 ~ 100mg 分别置于离心管中, 每 管加入 0.5 - lmL细胞裂解液,混匀,冰上间歇超声破碎 20 - 50s; 加入 5 - 15μί 质量比为 2 ~ 4:1的 DNase I /RNaseA酶混合溶液, 混匀, 静置反应 10 ~ 30min; 加入 5 ~ 15 L 80 ~ 120mM的苯 甲基磺酰氟异丙醇溶液, 4。C静置 l ~ 3h; 15000rpm 离心 25 ~ 40min; 取上清, 得到蛋白溶液;
所述细胞裂解液为: S mol'L 1 尿素,质量浓度为 4% 的 3-[(3 -胆酰胺丙基) -二乙胺卜丙磺酸, 40 mM 的 Tris,余量为水;
③蛋白浓度测定:
采用 Bradford试剂盒,将牛血清蛋白由低浓度到高浓度加入 考马斯亮蓝 G-250 溶液中, 测定步骤(2 ) ②获得的各个蛋白溶 液在 595nm处的吸光值, 建立标准曲线; 测定各个蛋白溶液蛋白 的浓度;
④沉淀蛋白
分别取含 50-100 蛋白的步骤( 2 )②获得的各个蛋白溶液, 每份加入 4 - 6倍体积的 -20 ~ -40*Ό的丙酮, 在 -20 ~ -40*Ό的 条件下放置 12 ~ 20h; 离心, 弃上清, 沉淀用 -20 ~ -40 的体积 浓度为 70%-85%的丙酮水溶液洗涤; 干燥得到蛋白干粉;
⑤蛋白还原以及酶解
分别向各个蛋白干粉中, 添加 20~40μ 40~60mM的三乙基 碳酸氢铵水溶液溶解蛋白; 再加入 l~4 L 三(2-羧乙基)膦, 在 50~60 还原反应 l-1.5h, 再加入 l~2 L 甲基硫代磺酸甲酯, 室 温反应 10~15min, 终止还原反应; 再加入 20~30μ 浓度为 0.2~0.3 g^L的胰蛋白酶水溶液, 37 蛋白酶解 12~18小时, 得 酶解液;
⑥蛋白标记
向步骤( 2 )⑤获得的各个酶解液中分别加入一管用 60~80μί 乙醇溶解的 iTRAQ标记试剂, 室温反应 l-1.5h;
⑦溶液混合
将步骤(2 )⑥标记后的各个来自巨大芽孢杆菌的蛋白溶液混 合; 将步骤(2 )⑥标记后的各个来自氧化葡糖杆菌的蛋白溶液混 合; 于 -40 保存;
⑧差异表达蛋白鉴定
将(2 )⑦中得到的两组混合液, 进行 Q-Tof质傳鉴定, 得到蛋白谱, 通过定量得到各混合组样品的差异表达蛋白;
( 3 )聚类分析:
采用 Expander4.0对步骤(2 ) ⑧中得到的数据进行标 准化后,进行 K-means聚类,得到具有不同变化规律的数据类别, 获得候选差异蛋白;
( 4 )过程分析
将步骤 ( 3 )获得的候选差异蛋白含量按照时间序列制成图表, 观察并分析这些蛋白变化的规律, 进而发现混菌进化培养在提高 氧化葡糖杆菌产 2-酮 -L-古龙酸过程中的作用。
5. 一种分析维生素 C生产菌株传代过程磷脂组变化的方法, 其特征是包括如下步骤:
( 1 ) 固体培养:
取 10-500 保藏于体积浓度为 15-30%的甘油水溶液中的 氧化葡糖杆菌 ( Gluconobacter oxydans )和 10-500 μL·保藏于体 积浓度为 15-30%的甘油水溶液中的巨大芽孢杆菌(Bacillus megaterium)分别接种于固体培养基上, 28_35。C,培养 24 h-48 h;
( 2 )种子培养:
将经步骤( 1 )培养的巨大芽孢杆菌和氧化葡糖杆菌分别转入 种子培养基,在 28_35°C, 200-280 rpm摇床振荡培养, 24 h-48 h, 得到巨大芽孢杆菌种子液和氧化葡糖杆菌种子液;
将巨大芽孢杆菌和氧化葡糖杆菌接种到新的种子培养基中, 使巨大芽孢杆菌的密度为 2xl07-2xlOie cfu/mL, 使氧化葡糖杆菌 的密度为 2X108-2X1011 cfu/mL, 在 28_35°C, 200-280 rpm摇床 振荡培养, 以 24 h-48 h为传代周期, 以体积比为 1%-10%为传 代比接入新的种子培养基中,传代 100-150天,在 0-100或 0-150 天选 3-5个取样时间取 3-5个样;
( 3 )分纯:
将步骤( 2 )获得的 3-5个传代培养混菌菌株划线分纯, 再分 别接种于固体培养基上, 28-35°C培养 24 h-48 h; 再分别转入种 子培养基, 在 28_35°C, 200-280 rpm摇床振荡培养 24 h_48 h, 得到进化了的巨大芽孢杆菌种子液和进化了的氧化葡糖杆菌种子 液;
( 4 )发酵:
将所述进化了的巨大芽孢杆菌、 进化了的氧化葡糖杆菌以及 混合的进化了的巨大芽孢杆菌和进化了的氧化葡糖杆菌分别接种 到发酵培养基中, 使进化了的 巨大芽孢杆菌的密度为
2Χ107-2Χ101 cfu/mL, 使进化了的氧化葡糖杆菌的密度为 2xl08-2xlOn cfu/mL, 在 28_35°C, 200-280 rpm摇床振荡培养 10 h-15 h;
( 5 ) 细胞磷脂组的提取:
①取在步骤(4 )摇床振荡培养 10 h-15 h 的三种细胞悬液 100-200 mL, 1000-3000 rpm离心 3-10 min, 去除上清液, 保留 细胞, 用 pH=7.2-7.4的磷酸盐緩冲液洗细胞 1-3次, 相同条件离 心, 去除上清, 得到细胞;
②将步骤①所得细胞制成干粉, 称取 200-300 mg细胞干粉, 置于离心管 A中, 加入 0.5-0.8 mL超纯水, 充分混匀;
③向离心管 A中再加入 2-4 mL提取液,充分混匀; 1000-3000 rpm离心 3-10 min, 使溶液分层, 取下层有机溶剂层, 置于离心 管 B中;
④重复步骤③ 2-4次, 至细胞完全沉降;
⑤向离心管 B中,加入 0.8-1.2 mol/L KC1水溶液 0.5—1.5 mL, 充分混匀, 2000-4000 rpm离心 3-10 min, 除去含水溶性杂质的 上清;
⑥再向离心管 B加入 1-3 mL超纯水, 充分混匀, 2000-4000 rpm离心 3-10 min, 去上清;
⑦蒸馏或氮气吹干步骤⑥所得混合物中的有机溶剂, 得到总 磷脂提取混合物;
⑧将所述总磷脂提取混合物溶于 0.2-2 mL储存液中制成样 品, 冷冻 -40°C以下保存;
⑨检测前, 向所述样品内加入磷脂标准品, 使磷脂标准品终 浓度为 0.5-1.5 g/mL;
所述提取液是含有二丁基羟基甲苯的氯仿 /甲醇溶液, 所述氯 仿 /甲醇的体积比为 1-2:1, 所述二丁基羟基甲苯的质量分数为 0.005-0.01%;
所述储存液为含有二丁基羟基甲苯的氯仿 /甲醇溶液, 所述氯 仿 /甲醇的体积比为 1-4:1, 所述二丁基羟基甲苯的质量分数为 0.005-0.01%;
( 6 ) LC-MS检测
采用 LC-MS对步骤( 5 )获得的加入了磷脂标准品的样品进 行检测, 得到维生素 C生产菌株传代过程的磷脂组的分子结构和 含量数据;
( 7 ) 多元统计分析
将步骤(6 )获得的维生素 C生产菌株传代过程的磷脂组的 分子含量数据, 进行多元统计分析, 得到区分不同传代时间维生 素 C生产菌株的差异磷脂分子标志物;
( 8 )过程分析
将步骤( 7 )获得的差异磷脂分子标志物的含量按照不同传代 时间制成图表, 观察并分析这些磷脂分子变化的规律, 进而发现 在混菌传代培养过程中起关键作用的磷脂分子及相关代谢途径, 从而为以提高 2-酮基 -L-古龙酸为目的的菌种改造和培养条件优 化提供方向;
优选地, 所述方法的特征是所述细胞制成干粉的方法为使用 液氮在研钵内研磨细胞;
优选地, 所述方法的特征是所述步骤(5 )⑦中所述蒸馏为 30-40°C减压蒸馏;
优选地, 所述方法的特征是所述磷脂标准品为磷脂酰甘油、 磷脂酰乙醇胺、 溶血性磷脂酰乙醇胺和磷脂酸至少两种;
优选地, 所述方法的特征是所述磷脂酰甘油,磷脂酰乙醇胺, 溶血性磷脂酰乙醇胺或磷脂酸的脂肪酸疏水尾长度为每条 10-20 个碳原子;
优选地, 所述方法的是所述 LC-MS检测条件为:
色镨柱: Hypersil GOLD Silica, 其规格为 150mm x 2.1mm,
5μπι;
进样量: 10 μί;
柱温: 25 °C;
流动相 A ( % ): 氯仿( 89.5 ), 甲醇( 10 ), 氢氧化铵( 0.5 ); 流动相 B ( % ): 氯仿( 55 ), 甲醇( 39 ), 氢氧化铵( 0.5 ), 水(5.5 ) ;
梯度程序: 0-7 min, 20-30% B; 7-15 min 30-40% B; 15-20 min 40-50% B; 20-25 min 50% B; 25-35min, 50-20% B; 35-45min, 20% B;
离子化方式: ESI (负离子方式) ;
扫描方式: MS Scan;
扫描范围: m/z 400— 900;
扫描速度: 1000 scan/s;
毛细管电压: 3 KV;
锥孔电压: 30 V;
萃取电压 3 V;
离子源温度: 100。C;
脱溶剂气温度: 350°C;
锥孔气流量: 50 L/Hr
脱溶剂气流量: 400 L/Hr;
进 /出口能量: 50;
碰撞能量: 2;
HM1/LM1/HM2/LM2: 15.0;
Ion Energy 1 : 1.0;
Ion Energy 2: 2.0;
优选地, 所述方法的特征是所述多元统计分析方法为 Pareto 预处理后进行主成分分析;
6. 一种检测维生素 C生产菌林传代过程中营养环境变化的 方法, 包括如下步骤:
( 1 )混菌传代培养:
①固体培养:
取保藏于体积浓度为 15-30%的甘油水溶液中的氣化葡糖杆 菌 ( Gluconobacter oxydans )和保藏于体积浓度为 15-30%的甘 油水溶液中的巨大芽孢杆菌(Bacillus megaterium)分别接种于固 体培养基上, 28-35 , 培养 24-48 h;
②种子培养:
将经步骤( 1 )①培养的巨大芽孢杆菌和氧化葡糖杆菌分别转 入种子培养基,在 28-35 , 200-280 r/min摇床振荡培养 24-48 h, 分别得到巨大芽孢杆菌种子液和氧化葡糖杆菌种子液;
将巨大芽孢杆菌和氧化葡糖杆菌接种到一个新的种子培养基 中, 使巨大芽孢杆菌的密度为 2xl07-2xlOie CFU/mL, 使氧化葡 糖杆菌的密度为 2X108-2X1011 CFU/mL,在 28-35 *€, 200-280 r/min 摇床振荡混菌培养, 以 24-48h为传代周期, 以体积比为 1%-10% 为传代比接入新的种子培养基中,传代 100-150天得到混菌细胞, 在传代 0-100天或 0-150天中选定 3-4个时间取样, 取 3-4个样;
③分纯:
将步骤( 1 )②获得的 3-4个样的混菌细胞划线分纯后再分别 接种于固体培养基上, 28-35 培养 24-48 h; 再分别转入新的种 子培养基, 在 28- 35*Ό, 200- 280 rpm摇床振荡培养 24- 48 h, 分 别得到巨大芽孢杆菌种子液和氧化葡糖杆菌种子液; 保藏于体积 浓度为 15-30%的甘油水溶液中;
④发酵:
将步骤( 1 )③获得的巨大芽孢杆菌和氧化葡糖杆菌以及将两 种菌混合在一起的混合菌, 分别接种到新的种子培养基中, 使巨 大芽孢杆菌的密度为 2xl07-2xlOie CFU/mL, 氧化葡糖杆菌的密 度为 2xl08-2xlOuCFU/mL, 在 28-35 , 200-280 r/min摇床振荡 培养 10-15 h;
( 2 ) 营养环境中物质的测定:
①培养液的收集: 分别取步骤( 1 )④获得的巨大芽孢杆菌培养液、 氧化葡糖杆 菌培养液和混菌体系培养液 1-2 mL, 以 5000-10000 rpm的转速 离心, 收集上清, 并用 0.22 μπι纤维素微孔滤膜过滤, 得滤液;
②样品制备:
取步碌( 2 K 获得的滤液 10-50 置于离心管中,加入 50-200 的 0.04-0.14 mg/ml氘标记的琥珀酸甲醇溶液为内标物, 冷冻 干燥; 加入 40-100 浓度为 20 mg/mL的甲氧基胺盐酸盐的吡 啶溶液于 30 -40 水浴中肟化反应 60-120 min; 再加入 50-100 μίΝ-甲基 -Ν-三甲基硅烷三氟乙酰胺于 35 -40 水浴进行硅烷 化反应 30-60 min;
③ GC-TOFMS检测:
将 1 步骤( 2 )②获得的样品进到气相色傳仪中, 色谱柱 为 DB-5MS, 所述色镨柱的规格为 30mx0.25mmi.d.,进样口温 度为 δθ ^δθ , 载气为高纯氦气, 流速 0.6-0.8ml/min, 分流 比 3: 1-20: 1,柱温箱升温程序为:初始 δθ -δθΧ ,保持 2min-5 min, 以 /πήη-δ /πήη的速度升到 όθ ^Οθ ,保持 3 min-8 min, 使用 EI 电离源, 源温 230*Ό-260<Ό, 检测器电压 2300 V-2700V, 电离电压 60 eV-80 eV, 电流 30 μΑ-50 μΑ; 质镨检测 范围 50-800 m/z; 营养环境物质的鉴定使用 NIST 2005数据库, 质谱数据的处理和营养环境物质相对含量的测定使用 Masslynx 4.1软件; 并通过对色傳峰面积积分处理,并与内标物的峰面积对 照, 得到营养环境物质的相对含量;
( 3 )主成分分析:
①将步骤(2)获得的营养环境物质的相对含量的数据 进行 Pareto预处理;
②用 Metlab 7.0 ( Mathworks. Inc. )软件对步骤( 3 )①预处 理后的数据进行主成分分析, 得到差异营养环境标志物;
( 4 )过程分析
将差异营养环境标志物的相对含量按照不同传代时间制成图 表, 观察并分析这些物质变化的规律, 检测出维生素 C生产菌株 传代过程中营养环境的变化。
7. 分析维生素 C生产菌株传代过程中小分子代谢物变化的 方法, 其特征是包括如下步骤:
( 1 )混菌传代培养:
①固体培养:
取保藏于体积浓度为 15-30%的甘油水溶液中的氧化葡糖杆 菌 ( Gluconobacter oxydans )和保藏于体积浓度为 15-30%的甘 油水溶液中的巨大芽孢杆菌(Bacillus megaterium)分别接种于固 体培养基上, 28-35 , 培养 24-48 h;
②种子培养:
将经步骤( 1 )①培养的巨大芽孢杆菌和氧化葡糖杆菌分别转 入种子培养基, 在 28-35 , 200-280 rpm摇床振荡培养 24-48 h, 分别得到巨大芽孢杆菌种子液和氧化葡糖杆菌种子液;
将巨大芽孢杆菌和氧化葡糖杆菌接种到一个新的种子培养基 中, 使巨大芽孢杆菌的密度为 2xl07-2xlOie CFU/mL , 使氧化葡 糖杆菌的密度为 2Χ108-2Χ10" CFU/mL ,在 28-35 , 200-280 rpm 摇床振荡培养, 以 24-48h为传代周期, 以体积比为 1 %-10%为传 代比接入新的种子培养基中, 传代 100-150天得到混菌细胞, 在 传代 0-100天或 0-150天中选定 3-4个时间取样, 取 3-4个样;
③分纯:
将步骤( 1 )②获得的 3-5个样的混菌细胞划线分纯后再分别 接种于固体培养基上, 28-35 培养 24-48 h; 再分别转入新的种 子培养基, 在 28-35 , 200-280 rpm摇床振荡培养 24-48 h, 分 别得到进化了的巨大芽孢杆菌种子液和氧化葡糖杆菌种子液; 保 藏于体积浓度为 15-30%的甘油水溶液中;
④发酵:
将步骤( 1 )③获得的进化了的巨大芽孢杆菌和氧化葡糖杆菌 以及将两种菌混合在一起的混合菌, 分别接种到新的种子培养基 中, 使进化了的巨大芽孢杆菌的密度为 2Χ107-2Χ101 CFU/mL, 进化了的氧化葡糖杆菌的密度为 SxloS xloUCFU/mL , 在 28-35*Ό, 200-280rpm摇床振荡培养 10-15 h;
( 2 )胞内小分子代谢物样品的制备和测定:
①各取在步骤( 1 ) ④获得的三种细胞悬液 100-200 mL, 分 别在 1000-3000 rpm离心 3-10 min, 去除上清液, 保留细胞, 用 pH=7.2-7.4的磷酸盐緩冲液洗细胞 1-3次, 相同条件离心, 去除 上清, 得到细胞;
②将步骤( 2 )①所得细胞制成干粉, 各称取 30-60 mg细胞 干粉, 分别置于三个离心管中, 再加入 0.5-1.5 mL提取液, 加入 30-70μί浓度为 0.020-0.060mg/mL氘标记的琥珀酸甲醇溶液为内 标物, 混匀; 1000-3000 rpm离心 3-10 min, 取上清液置于三个 新的离心管中冷冻干燥;
③将步骤( 2 )②获得三个离心管中分别加入 40-100 μΐ,浓度 为 10-30 mg/mL的甲氧基胺盐酸盐的吡啶溶液于 水浴 中肟化反应 60-120 min; 再加入 50-100μ Ν-甲基 -Ν-三甲基硅烷 三氟乙酰胺于 35 -40 水浴进行硅烷化反应 30-60 min;
所述提取液为体积分数为 50-70%的甲醇水溶液;
④ GC-TOF/MS检测: 将 1 步骤( 2 )③获得的样品进到气相色傳仪中, 色谱柱 为 DB-5MS, 所述色镨柱的规格为 30 mx0.25mmi.d.,进样口温 度为 Ζδθ ^δθ ,载气为高纯氦气, 恒压 80-100KPa,分流比 3: 1-20: 1,柱温箱升温程序为: 初始 δθ -δθ ,保持 3 min-6min, 以 4'C/min-8,O/min的升到 260'Ό-300,Ό, 保持 3 min-8 min, 使 用 EI电离源, 源温 230*Ό-260<Ό, 检测器电压 2300 V-2700V, 电 离电压 60 eV-80 eV,电流 30 μΑ-50 μΑ;质傳检测范围 50-800 m/z; 小分子代谢物的鉴定使用 NIST2005数据库, 质谱数据的处理和 代谢物相对含量的测定使用 Masslynx4.1软件; 并通过对色谱峰 面积积分处理, 并与内标物的峰面积对照, 得到小分子代谢物的 相对含量;
( 3 )主成分分析:
①将步骤(2)④获得的维生素 C生产菌株传代过程的小分 子代谢物的相对含量数据进行 Pareto预处理;
②用 SIMCA-P 11.5软件对预处理后的数据进行主成分分析, 得到区分不同传代时间维生素 C 生产菌株的小分子代谢物标志 物;
( 4 )过程分析
将小分子代谢物标志物的含量按照不同传代时间制成图表, 观察并分析小分子代谢物标志物变化的规律, 检测出维生素 C生 产菌株传代过程中细胞内小分子代谢物的变化,
优选地, 其中所述细胞制成干粉的方法为液氮研磨细胞。
8. 含有编码山椠酮脱氢酶基因载体的氧化葡糖杆菌的用途, 其特征是将含有编码山椠酮脱氢酶基因载体的氧化葡糖杆菌和巨 大芽孢杆菌接种到发酵培养基中, 培养, 获得 2-酮基 -L-古龙酸; 优选地, 所述含有编码山椠酮脱氢酶基因载体的氧化葡糖杆 菌的构建为:
( 1 ) 山椠酮脱氢酶基因的体外扩增:
采用细菌基因组提取试剂盒提取氧化葡糖杆菌的基因组为模 板; 以 SEQ ID No.l所示序列为上游引物, 以 SEQ ID No.2所示 序列为下游引物, 进行 PCR扩增, 回收 PCR扩增产物;
( 2 )编码山椠酮脱氢酶基因载体的构建:
取步骤( 1 )获得的 PCR扩增产物用 Hindlll酶和 BamHI 酶默酶切;取载体 pBBRl用 Kpnl酶和 Hindlll酶默酶切;连接, 转化入大肠杆菌 DH5a中, 获得编码山椠酮脱氢酶基因载体;
( 3 )编码山椠酮脱氢酶基因载体转化入氧化葡糖杆菌 将氧化葡糖杆菌涂布在固体培养基上,在 30。C条件下培养 48 小时; 用 2ml无菌水将菌体洗下, 冰浴 10min, 4*Ό, 4000rpm离 心 5min后收集细胞, 用预冷的无菌水洗一次, 10%甘油洗两次 后, 100μ1 10%甘油重悬细胞; 与步骤(2 )所得编码山椠酮脱氢 酶基因载体的水溶液 ΙΟμΙ混合均匀置于电转杯中, 冰浴 5min, 将电转杯置于电转仪中 1800V电击; 电击产物与 900μ1种子培养 基混合均匀, 在 30。C, 140rpm条件下培养 2小时, 将培养物涂 布于固体培养基上, 在 30。C条件下培养 4天, 获得的单菌落转入 种子培养基中, 在 30。C, 250rpm条件下培养, 获得含有编码山 椠酮脱氢酶基因载体的氧化葡糖杆菌;
更优选地, 含有编码山椠酮脱氢酶基因载体的氧化葡糖杆菌 的构建为:
( 1 ) 山椠酮脱氢酶基因的体外扩增:
采用细菌基因组提取试剂盒提取氧化葡糖杆菌的基因组; 取 该基因组溶液 1μ1, 5 FastPfu buffer 4μ1, 20mM的 dNTP 2μ1, 20nM的引物 1 0·4μ1, 20nM的引物 2 0·4μ1,无菌水 11·8μ1, FastPfu 酶 0.4μ1, 在 PCR管中混合均匀; 将 PCR管放入 PCR仪中进行 扩增循环, 扩增程序为: 95。C 2min; 95 °C 20s, 55 °C 35s, 72 °C 2min, 共 25个循环; 72 °C 5min; 4。C 30min; 将 PCR产物进行 琼脂糖凝胶电泳,将 PCR产物条带切下,经琼脂糖凝胶回收试剂 盒纯化 PCR扩增产物;
所述引物 1的序列为: 5,- CCCAAGCTTGACTGGCAGCAGCGCAAC-3'
所述引物 2的序列为: 5,-
CGCGGATCCCCGTGATAGCGGCACATGTC-3'
( 2 )编码山椠酮脱氢酶基因载体的构建:
取步骤(1 )获得的 PCR扩增产物溶液 8μ1,与 Ιμΐ 10 X digest buffer, 0.5μ1 Hindlll酶, 0.5μ1 BamHI酶混合均匀, 在 37。C条 件下进行酶切反应 2小时; 反应后产物进行琼脂糖凝胶电泳, 将 酶切产物条带切下, 经琼脂糖凝胶回收试剂盒纯化酶切 PCR产 物;取载体 pBBRlMCS溶液 8μ1, 与 Ιμΐ 10 x digest buffer, 0.5μ1 ΚρπΙ酶, 0.5μ1 Hindlll酶混合均匀, 在 37。C条件下进行酶切反 应 2小时; 反应后产物进行琼脂糖凝胶电泳, 将酶切产物条带切 下,经琼脂糖凝胶回收试剂盒纯化酶切载体产物;取酶切 PCR产 物 5.5μ1, 酶切载体产物 3μ1, 10 ligase buffer 1μ1, DNA ligase 0.5μ1, 混合均匀, 在 22。C条件下进行连接反应 30min; 将连接产 物用化学转化法转化入大肠杆菌 DH5a中,涂布于含抗生素的 LB 固体培养基上, 在 37。C条件下培养 12h; 培养后获得的单菌落在 LB液体培养基中 37。C培养 12h, 用质粒小量提取试剂盒提取质 粒, 获得编码山椠酮脱氢酶基因载体;
( 3 )编码山椠酮脱氢酶基因载体转化入氧化葡糖杆菌 将氧化葡糖杆菌涂布在固体培养基上,在 30。C条件下培养 48 小时; 用 2ml无菌水将菌体洗下, 冰浴 10min, 4*Ό, 4000rpm离 心 5min后收集细胞, 用预冷的无菌水洗一次, 10%甘油洗两次 后, 100μ1 10%甘油重悬细胞; 与步骤(2 )所得编码山椠酮脱氢 酶基因载体的水溶液 ΙΟμΙ混合均匀置于电转杯中, 冰浴 5min, 将电转杯置于电转仪中 1800V电击; 电击产物与 900μ1种子培养 基混合均匀, 在 30。C, 140rpm条件下培养 2小时, 将培养物涂 布于固体培养基上, 在 30。C条件下培养 4天, 获得的单菌落转入 种子培养基中, 在 30。C, 250rpm条件下培养, 获得含有编码山 椠酮脱氢酶基因载体的氧化葡糖杆菌;
所述固体培养基为: L-山椠糖 20g, 玉米浆 3g, 牛肉骨 3g, 酵母浸粉 3g, 尿素 lg, 蛋白胨 10g, 琼脂 20g, KH2P04lg, MgSO40.2g, CaC03lg,加水至 1L,调 pH为 6.8, 121 "Ό灭菌 20min;
所述种子培养基为: L-山椠糖 20g, 玉米浆 3g, 牛肉骨 3g, 酵母浸粉 3g, 尿素 lg, 蛋白胨 10g, KH2P04lg, MgSO40.2g, CaC03lg, 加水至 1L, 调 pH为 6.8, 121*Ό灭菌 20min;
( 4 )混菌发酵
将步骤( 3 )获得的含有编码山椠酮脱氢酶基因载体的氧化葡 糖杆菌和巨大芽孢杆菌接种到发酵培养基中, 使含有编码山椠酮 脱氢酶基因载体的氧化葡糖杆菌的密度为 4 x l08cfu/ml ,使巨大 芽孢杆菌的密度为 4 x 108 cfu/ml, 在 30*Ό, 250rpm条件下培养 120h, 获得 2-酮基 -L-古龙酸;
所述发酵培养基为: 按比例称取 L-山椠糖 80g, 玉米浆 20g, 尿素 12g, KH2P04lg, MgSO40.5g, CaC03lg, 加水至 1L, 调 pH为 7.0, 121*Ό灭菌 20min。
9. 一种检测谷胱甘肽作用于氧化葡糖杆菌过程中细胞内蛋 白质变化的方法, 其特征是包括如下步骤:
(1) 细胞内蛋白质的测定:
①细胞收集及淬灭:
取 3-5份氧化葡糖杆菌以 8%~16%的体积比分别接种到发酵 培养基 A中, 另取 3-5份所述氧化葡糖杆菌以 8%~16%的体积比 分别接种到发酵培养基 B 中, 将两种接种后的培养基在 28 ~32 , 转速为 200~250rpm的条件下培养发酵, 在发酵过程中选 取 1 h、15h为取样点取出发酵液样品,在 下,以 4000~6000rpm 的转速离心, 收集下层的细胞, 并用 pH为 7.2~7.4的磷酸盐緩冲 液清洗, 用液氮淬灭, 终止代谢反应; 用液氮研磨破碎细胞, 获 得 3-5份从培养基 A中发酵 1 h收集淬灭的破碎细胞, 3-5份从培 养基 A中发酵 15 h收集淬灭的破碎细胞, 3-5份从培养基 B中 发酵 lh收集淬灭的破碎细胞, 3-5份从培养基 B中发酵 15h收 集淬灭的破碎细胞;
所述发酵培养基 A为: 80 g*L 山椠糖 Og'L1 玉米浆, 1 g*L 1 KH2P04, 0.2 g*L 1 MgS04,和 12 g*L 1 尿素, 余量为水; 所述发酵培养基 B为: SOg'L1 山椠糖 Og'L1 玉米浆, 1 g*L 1 KH2P04, 0.2 g*L 1 MgS04, and 12 g*L 1 尿素, 0.8~1.5mg* mL1的谷胱甘肽, 余量为水;
②提取细胞内蛋白:
取步骤①获得的破碎细胞, 每份 100~200mg 分别置于离心 管中, 每管加入 0.5 ~ 2ml细胞裂解液, 混匀, 冰上间歇超声破碎 20 ~ 50s; 加入 5 ~ 15μί 的质量比为 2 ~ 4:1的 DNase I /RNaseA 酶混合溶液, 混匀, 静置反应 10~30min; 加入 5 ~ 15 L 80 ~ 120mM的苯甲基磺酰氟异丙醇溶液, 4。C静置 l~3h; 15000rpm 离心 25 ~ 40min; 取上清, 得到蛋白溶液; 所述细胞裂解液为: 8 mol'L 1 尿素,质量浓度为 4% 的 (3-[(3 -胆酰胺丙基) -二乙胺】 - 丙磺酸), 40 mM 的 Tris,余量为水;
③蛋白浓度测定:
采用 Bradford试剂盒,将牛血清蛋白由低浓度到高浓度加入 考马斯亮蓝 G-250 溶液中, 测定步骤②获得的各个蛋白溶液在 595nm处的吸光值, 建立标准曲线; 测定各个蛋白溶液蛋白的浓 度;
④沉淀蛋白
分别取包含 50~150 蛋白的步骤③获得的各个蛋白溶液, 加入 4 ~ 6倍体积的 -20 ~ -40*Ό的丙酮, 沉淀 12 ~ 20h; 离心, 弃上清, 沉淀用 -20 ~ -40 的体积浓度为 70%-85%的丙酮水溶 液洗涤; 冷冻干燥备用; 贮存;
⑤蛋白还原以及酶解
向步骤④所得的各个干燥蛋白中, 添加 10~40μί 40~60mM 的三乙基碳酸氢铵水溶液溶解蛋白;
加入 l~4 L 三(2-象乙基)膦, 在 50~60*Ό反应 lh, 对各个 蛋白进行还原化处理; 然后加入 l~2 L甲基硫代磺酸甲酯, 室温 反应 10~15min, 终止还原反应;
向上述溶液中, 加浓度为 0.2~0.3 g/ L 的胰蛋白酶水溶液 20~30μί, 37 反应 12~18小时, 进行蛋白酶解;
⑥蛋白标记
在每个经步骤⑤酶解的蛋白酶解液中分别加入一管用 60~80μί乙醇溶解的 iTRAQ标记试剂, 室温反应 lh;
⑦溶液混合
将步骤溶液⑥获得的溶液混合得 3-5份混合液, 使每个混合 液中都包括从培养基 A中发酵 1 h收集淬灭的破碎细胞再经步骤 ②-⑥后获得的标记蛋白、 从培养基 A中发酵 15 h收集淬灭的破 碎细胞再经步骤②-⑥后获得的标记蛋白、 从培养基 B中发酵 1 h 收集淬灭的破碎细胞再经步骤②-⑥后获得的标记蛋白和从培养 基 B中发酵 15 h收集淬灭的破碎细胞再经步骤②-⑥后获得的标 记蛋白; 于 -20 保存;
⑧差异表达蛋白鉴定
将⑦中得到的混合液, 进行 Q-Tof质傳鉴定, 得到蛋白 谱, 通过定量得到各混合组样品的差异表达蛋白;
( 2 )主成分分析:
采用 matlab 对步骤(1 ) ⑧中得到的数据进行标准化 后, 进行主成分分析, 得到具有不同变化规律的数据类别, 获得 候选差异蛋白;
( 3 )过程分析
将步骤 ( 2 )获得的候选差异蛋白含量按照时间序列制成图表, 观察并分析这些蛋白变化的规律, 进而发现谷胱甘肽在提高氧化 葡糖杆菌产 2-酮 -L-古龙酸过程中的作用。
10. 寻找发酵用原料玉米浆的质量控制指标的方法, 其特征 是包括下述步骤:
( 1 )对玉米浆的化学成分的测定:
① 样品的制备:
将 0.5-2g均匀的发酵用原料玉米浆置于离心管中, 离心收集 上清; 将获得的上清液用超纯水稀释 10-40体积倍, 取 10-40μί 置于另一离心管中, 加入 30-50μ 的 0.040mg/mL氣标记的琥珀 酸甲醇溶液为内标;冷冻干燥后,加入 50-100μί浓度为 20mg/mL 的甲氧基胺盐酸盐的吡啶溶液于 水浴中肟化反应 60-120min; 再加入 60-100μ Ν-甲基 -N-三甲基硅烷三氟乙酰胺于 35 -40 水浴进行硅烷化反应 20-50min;
②气相色谱-飞行时间质傳联用仪测定方法:
将 Ιμΐ 步骤①获得的样品进到气相色谱中, 色谱柱为 DB-5MS, 所述色镨柱的规格为 30 mx0.25 mm i.d., 进样口温度 ISO -ISOX , 载气为高纯氦气, 流速 0.6-0.8ml/min, 分流比 30:
1-10: 1,柱温箱升温程序为: 初始 。^^。^保持 ^!^!!, 以
/min-S /min的速度升到 δθ ^Οθ , 保持 8-10min, 使用 EI 电离源, 源温 ZSO ^SO , 检测器电压 2300V-2700V, 电离电 压 60eV-80eV, 电流 30μΑ-50μΑ; 质镨检测范围 50-800m/z; 成 分的鉴定使用 NIST数据库, 质谱数据的处理和成分相对含量的 测定使用 Masslynx 4.1软件; 并通过对色傳峰面积积分处理, 并 与内标物的峰面积对照, 得到发酵用原料玉米浆中化学成分的相 对含量;
( 2 )偏最小二乘判别分析法
①将方法( 1 )获得的数据进行标准化和预处理;
②用 SIMCA-P 11.5软件对预处理后的数据进行偏最小二乘 法判别分析, 得到用于表达样本相似性和差异性的得分图、 载荷 图和 VIP图; 在得分图中, 样品点相互之间距离越近, 说明样本 的相似度越大, 距离越远, 说明样本差异越大, 可用来寻找不同 批次玉米浆中各物质的相似和差异; 在载荷图中, 每个点表示每 个物质, 距离中心点距离越远的物质, 其在不同批次的含量差异 越大, 便可作为玉米浆的质量控制指标; VIP表示每个物质对区 分样本的贡献大小, VIP>1可以认为是对玉米浆质量影响最为显 著的指标。
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| CN 201110314740 CN102352403B (zh) | 2011-10-17 | 2011-10-17 | 混菌进化传代培养提高2-酮基-l-古龙酸产量的方法 |
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| CN201110346058.8 | 2011-11-04 | ||
| CN201110346058.8A CN102520184B (zh) | 2011-11-04 | 2011-11-04 | 检测谷胱甘肽作用于氧化葡糖杆菌过程中细胞内蛋白质变化的方法 |
| CN2011104070781A CN102492762A (zh) | 2011-12-09 | 2011-12-09 | 含有编码山梨酮脱氢酶基因载体的氧化葡糖杆菌的用途 |
| CN201110407078.1 | 2011-12-09 | ||
| CN201210044060.4A CN102586386B (zh) | 2012-02-24 | 2012-02-24 | 一种分析维生素c生产菌株传代过程磷脂组变化的方法 |
| CN201210044060.4 | 2012-02-24 | ||
| CN2012100494407A CN102590324A (zh) | 2012-02-29 | 2012-02-29 | 检测维生素c工业混菌传代不同代数蛋白质变化的方法 |
| CN201210049440.7 | 2012-02-29 | ||
| CN2012101096286A CN102634562A (zh) | 2012-04-13 | 2012-04-13 | 检测维生素c生产菌株传代培养过程中营养环境变化的方法 |
| CN201210109628.6 | 2012-04-13 | ||
| CN201210148033.1 | 2012-05-14 | ||
| CN201210148033.1A CN102680562B (zh) | 2012-05-14 | 2012-05-14 | 分析vc生产菌株传代过程中小分子代谢物变化的方法 |
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| WO2012174978A1 true WO2012174978A1 (zh) | 2012-12-27 |
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Cited By (4)
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| CN103045710A (zh) * | 2011-10-17 | 2013-04-17 | 天津大学 | 强化两菌相互作用提高2-酮基-l-古龙酸产量的方法 |
| CN111909971A (zh) * | 2020-08-14 | 2020-11-10 | 山东鲁维制药有限公司 | 一种酸胁迫减弱发酵产酸能力基因的混合发酵培养方法 |
| CN114292893A (zh) * | 2022-01-05 | 2022-04-08 | 山东天力药业有限公司 | 一种在vc混菌种子罐中添加多种微量元素缩短发酵周期提高产酸收率的方法 |
| CN117243885A (zh) * | 2023-11-15 | 2023-12-19 | 北京青藤谷禧干细胞科技研究院有限公司 | 一种改善皮肤的干细胞外泌体组合物及其制备方法 |
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| Publication number | Priority date | Publication date | Assignee | Title |
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| EP3194559A1 (de) | 2015-11-27 | 2017-07-26 | Technische Universität Ilmenau | Verfahren und anordnung zur fermentation |
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| CN111909971A (zh) * | 2020-08-14 | 2020-11-10 | 山东鲁维制药有限公司 | 一种酸胁迫减弱发酵产酸能力基因的混合发酵培养方法 |
| CN114292893A (zh) * | 2022-01-05 | 2022-04-08 | 山东天力药业有限公司 | 一种在vc混菌种子罐中添加多种微量元素缩短发酵周期提高产酸收率的方法 |
| CN114292893B (zh) * | 2022-01-05 | 2023-08-29 | 山东天力药业有限公司 | 一种在vc混菌种子罐中添加多种微量元素缩短发酵周期提高产酸收率的方法 |
| CN117243885A (zh) * | 2023-11-15 | 2023-12-19 | 北京青藤谷禧干细胞科技研究院有限公司 | 一种改善皮肤的干细胞外泌体组合物及其制备方法 |
| CN117243885B (zh) * | 2023-11-15 | 2024-01-26 | 北京青藤谷禧干细胞科技研究院有限公司 | 一种改善皮肤的干细胞外泌体组合物及其制备方法 |
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| Publication number | Publication date |
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| DE112012002557T5 (de) | 2014-03-20 |
| DE112012002557B4 (de) | 2018-05-09 |
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