Utilize the method for juice of sugar grass stalks glutathion production by fermentation
Technical field
The present invention relates to a primary yeast and produce the method for gsh, particularly a kind of method of utilizing the juice of sugar grass stalks glutathion production by fermentation belongs to technical field of biotechnology.
Background technology
Gsh (Glutathione, GSH) be a kind of material with important physiologically active, it is the tripeptide compound that is formed by the peptide bond condensation by L-glutamic acid, halfcystine and glycine, it is a kind of broad-spectrum active polypeptide, its chemical name is γ-L-paddy ammonia phthalein-L-half Guang ammonia phthalein-glycine, and molecular formula is C
10H
18O
6N
3S.Gsh has oxidized form and two kinds of forms of reduced form, and reduced glutathion has physiologically active, and the Sleep-promoting factor B in the organism need reduce back competence exertion its physiological function.
Gsh extensively is present in animal, plant, the microorganism.The physiological action of gsh (GSH) is many-sided in vivo; as amino acid whose transhipment; synthesizing of albumen, nucleic acid; antioxygenation; keep the reduced state of albumen sulfydryl; keep the active condition of enzyme, the shunting of bonding phosphohexose, the protection cell prevents free radical and endotoxic damage etc.
Gsh (GSH) for radioactive rays, radiopharmaceuticals or since the symptoms such as oligoleukocythemia that antitumor drug causes can play a protective role.GSH can combine with the toxic compounds that enters body, heavy metal ion or carcinogenic substance etc., and short its excrete, in playing and detoxification.In addition, gsh can also suppress ethanol infringement liver generation fatty liver.
At field of food, gsh can be made seasonings, flavour agent, the antioxidant of various processed foods, can prolong effective period of food quality greatly, and gsh also has the effect of amino acid nutrient in the nutrient fortified food.
The production method of gsh mainly contains extraction method, chemical synthesis, fermentation method and enzyme process.
Fermentation method is by a large amount of cultivations of microorganism cells being extracted the method for GSH, because fermentative Production GSH has advantages such as bacterial classification is easy to cultivation, the convenient cheapness of raw material sources, reactions steps is simple, cost is low, transformation efficiency is high, throughput rate is fast, become the main method of current production gsh.
Since deRey-Pailhade isolates gsh from yeast after, from the yeast cell that can accumulate gsh in a large number, extract gsh, become the method that present production gsh generally adopts.Yeast is the bacterial classification that industrial production GSH extensively adopts, and yeast fermentation process is raw material with glucose etc. mainly, adopts mode disposable or that stream adds to carry out the cultivation of yeast cell, with the acquisition gsh; Also there is employing in the yeast culture base, to add the mode of the precursor L-L-glutamic acid of synthesizing glutathion, L-halfcystine, glycine to improve the productive rate of yeast gsh.The price of L-L-glutamic acid, L-halfcystine, glycine is higher, though add the productive rate that they can improve gsh when yeast fermentation, its production cost increases substantially; And glucose is the hydrolysate of starchiness grain, produce gsh with glucose fermentation and exist the problem of fighting for food with the human and animal, China is populous nation, grain resource is most valuable, the utilization of grain is the significant problem that is related to national economy, at present countries in the world all utilize non-grain raw material to carry out bio-transformation to obtain the material of necessary for human advocating energetically, and this Sustainable development to the world today has great importance.
Sweet sorghum also cries sugared Chinese sorghum, belongs to high light efficiency C
4Plant is the mutation of grain sorghum.The adaptability of sweet sorghum is stronger, has advantages such as drought-resistant, salt tolerant alkali, and the poor soil that is difficult to grow food crop such as corns has higher output on the ground.The biomass of sweet sorghum is high, and general per hectare is produced the bright stem stalk of sweet sorghum 60000~90000kg, and the crushing juice rate of its stem stalk generally about 60wt%, contains materials such as carbohydrate, protein, amino acid, VITAMIN, micro-metals in its juice.The content of the soluble sugar in the sweet sorghum stalk squeezeding juice mainly is made up of sucrose, glucose, fructose and a spot of other carbohydrate at 10wt%~20wt%.Sweet sorghum is as the recyclable regenerative crop, and the material that utilizes its stalk juice to substitute cereal production necessary for human is very necessary, also is feasible.
Sweet sorghum stalk is the byproduct behind the sweet sorghum grain harvest, utilizes the stalk juice of sweet sorghum to produce alcohol fuel existing report widely at home and abroad, but utilizes the juice of sugar grass stalks glutathion production by fermentation that report is not arranged as yet.Gsh is a kind of high value-added product, the substratum that the gsh of yeast production at present generally adopts is to be carbon source with glucose, add the synthetic substratum of raw materials such as nitrogenous source, inorganic salt, somatomedin, thereby cause the production cost height, compressed the profit margin of enterprise.
Summary of the invention
The present invention is directed to the deficiencies in the prior art, a kind of method with the juice of sugar grass stalks glutathion production by fermentation is provided.
Method of the present invention is to utilize the enzyme system of yeast cell self, with the method for the material synthesizing glutathions such as carbohydrate that contained in the juice of sugar grass stalks, thereby reduces the production cost of gsh, reaches the better economic effect.
For achieving the above object, the technical scheme taked of the present invention is:
A kind of method of utilizing the juice of sugar grass stalks glutathion production by fermentation is characterized in that step is as follows:
(1) yeast cell that will have glutathione synthetase system and a glycolysis-activity is inoculated on the slant medium and activates, cultivate 48h for 28~30 ℃, then, getting yeast cell from slant medium inserts the 10mL liquid seed culture medium, cultivate 24h down at 28~30 ℃, carry out enlarged culturing one time, insert liquid seed culture medium with 5wt%~10wt% inoculum size then and carry out the secondary enlarged culturing, under 28~30 ℃, 100~200r/min, cultivate 16~20h, make the live yeast cell;
(2) fresh sweet sorghum stalk is squeezed taking juice with squeezing machine, filtering separation is got filtrate, and being diluted to sugar degree is 4wt%~7wt%, transfers pH=5.0~6.0 with acid then, after mixing, and sterilization, cooling makes fermention medium;
(3) the live yeast cell that step (1) is made is inoculated in the fermention medium that step (2) makes by the inoculum size of 5wt%~10wt%, under leavening temperature is 28~32 ℃, the control condition of saturation dissolved oxygen 20%~40%, fermentation 30h~40h gets fermented liquid;
(4) fermented liquid that step (3) is made carries out the centrifugation yeast cell under 28~30 ℃ condition, and then wash resuspended, in 100 ℃ of boiling water baths the heating 3 minutes, gsh stripping with in the yeast cell is cooled to room temperature, and is centrifugal, concentrated supernatant makes gsh.
The yeast cell that has glutathione synthetase system and glycolysis-activity in the described step (1) is yeast saccharomyces cerevisiae (Saccharomyces cerevisiae), candiyeast (Candida Berkhout), pichia (Pichia Hansenula); Described yeast saccharomyces cerevisiae (Saccharomyces cerevisiae) is yeast saccharomyces cerevisiae CICC 1494, yeast saccharomyces cerevisiae CICC 1698, yeast saccharomyces cerevisiae CICC1699, yeast saccharomyces cerevisiae CICC1703, yeast saccharomyces cerevisiae CICC1438, yeast saccharomyces cerevisiae CICC1955, yeast saccharomyces cerevisiae CICC31256, yeast saccharomyces cerevisiae CICC31206, yeast saccharomyces cerevisiae CICC31205, yeast saccharomyces cerevisiae CICC31055.Above yeast saccharomyces cerevisiae all is preserved in Chinese industrial microbial strains preservation administrative center (CICC), can obtain by the mode of buying.
Slant medium in the described step (1), component following (g/L): glucose 20, peptone 20, yeast extract paste 10, agar 20, pH6.0.
Liquid seed culture medium in the described step (1), component following (g/L): glucose 20, peptone 20, yeast extract paste 10, KH
2PO
42, MgSO
41, pH6.0.
Fresh sweet sorghum stalk in the described step (2) is the remaining stem stalk part that contains sugar in sweet sorghum results back, crushing juice rate is 55wt%~65wt%, sugar degree in the juice behind the stem stalk pressure extracting juice is at 10wt%~20wt%, and the main component of contained sugar is sucrose, glucose and fructose.
Sterilization in the described step (2) is the 20min that sterilizes under 121 ℃ condition.
Acid in the described step (2) is sulfuric acid.
The positively effect that the present invention utilizes juice of sugar grass stalks to produce the yeast gsh is:
(1) finds after deliberation, the stalk juice that can be grown in the sweet sorghum on the saltings can directly be used as microzyme culture medium, and need not add other nutritive substance, therefore, the present invention is raw material with the juice of sugar grass stalks, utilizing enzyme own in the yeast cell is synthesizing glutathion, is the gsh of natural structure.
(2) the present invention is the raw material production gsh with the juice of sugar grass stalks, and lower than the production cost that with glucose is raw material, the gsh quality of preparation is good, has saved grain, meets the industry policy of country.
(3) the present invention provides a kind of new raw materials for production for gsh production, and simple with the technology of this raw material production gsh, can promote this product further to develop, and has huge economic benefit and social benefit.
(4) the present invention utilizes agricultural by-products stem stalk to carry out microbial transformation, has solved agricultural crop straw and has utilized irrational problem, and the stalk slag that the while sweet sorghum stalk is got behind the juice can be made the animal feed or be used as building and ornament materials through handling.
Embodiment
Utilize the method for juice of sugar grass stalks glutathion production by fermentation to specifically describe or be described further below in conjunction with example to the present invention, purpose is that methods of this invention will be better understood, but protection scope of the present invention is not limited to following embodiment.
Embodiment 1
Bacterial classification: yeast saccharomyces cerevisiae (Saccharomyces cerevisiae) CICC1955 (preservation of Chinese industrial microbial strains preservation administrative center).Sweet sorghum stalk is taken from hundred mu of saltings sweet sorghum production model fields on Dongying Guang Bei farm, and its stalk crushing juice rate is about 60wt%.The squeeze the juice squeezing machine of usefulness of sweet sorghum stalk is the cane mill that Guangxi De Baoxian machine works produces, and throughput is 1T/h.
A kind of method of utilizing the juice of sugar grass stalks glutathion production by fermentation, step is as follows:
(1) yeast cell that will have glutathione synthetase system and a glycolysis-activity is inoculated on the slant medium and activates, cultivate 48h for 28 ℃, then, getting yeast cell from slant medium inserts the 10mL liquid seed culture medium, cultivate 24h down at 28 ℃, carry out enlarged culturing one time, insert liquid seed culture medium with the 10wt% inoculum size then and carry out the secondary enlarged culturing, under 30 ℃, 100r/min, cultivate 16h, make the live yeast cell;
(2) fresh sweet sorghum stalk is squeezed taking juice with squeezing machine, filtering separation is got filtrate, and the sugar degree of filtrate is 15wt%, it is 5wt% that filtrate is diluted to sugar degree, transfers pH=5.5 with sulfuric acid then, after mixing, 121 ℃ of sterilization 20min are cooled to 30 ℃, make fermention medium;
(3) the live yeast cell that step (1) is made is inoculated in the fermention medium that 200mL step (2) makes by the inoculum size of 10wt%, be 30 ℃ at leavening temperature, shake under the condition that bottle rotating speed is 200r/min (saturation dissolved oxygen is 30%), fermentation 36h gets fermented liquid;
(4) fermented liquid that step (3) is made carries out the centrifugation yeast cell under 30 ℃ condition, and then wash resuspended, in 100 ℃ of boiling water baths the heating 3 minutes, gsh stripping with in the yeast cell is cooled to room temperature, and is centrifugal, concentrated supernatant makes gsh;
Slant medium in the described step (1), component following (g/L): glucose 20, peptone 20, yeast extract paste 10, agar 20, pH6.0; Seed culture medium (g/L): glucose 20, peptone 20, yeast extract paste 10, KH
2PO
42, MgSO
41, pH6.0;
Liquid seed culture medium in the described step (1), component following (g/L): glucose 20, peptone 20, yeast extract paste 10, KH
2PO
42, MgSO
41, pH6.0.
DTNB colorimetric method for determining gsh:
The DTNB storage liquid is the DTNB solution that is dissolved in 0.05mol/L phosphoric acid buffer (pH7.0) of 0.01mol/L.Use the Tris-HCl damping fluid of 0.5mol/L, pH8.0 to dilute 100 times the DTNB storage liquid, be made into the DTNB analytic liquid, lucifuge is placed, and is now with the current.
During mensuration, get gsh standard solution or sample solution (0.1~3.0mol/L) 0.5mL, adding 1.5mL concentration is the NaOH solution of 0.15mol/L, the formaldehyde solution that adds 0.5mL3% again, react 2min down at 25 ℃, extract reaction solution 0.5mL and add the DTNB analytic liquid, react 5min down at 25 ℃, under wavelength 412nm, measure light absorption value.
After testing, the content of gsh is 563mg/L, is 1689mg/L with respect to the content of juice of sugar grass stalks gsh.
In this embodiment, the crushing juice rate of the bright stalk of sweet sorghum is 60wt%, and the procurement price of the bright stalk of every 1000kg is about 300 yuan, and then the raw materials cost of every liter of stem stalk juice is 0.50 yuan, and the raw materials cost of producing gsh is 0.297 yuan of every gram.
Embodiment 2
As the embodiment 1 described method of utilizing the juice of sugar grass stalks glutathion production by fermentation, difference is:
The sugar degree of juice of sugar grass stalks is diluted to 4wt%, the Chinese sorghum stem stalk juice fermention medium of getting 200mL the shaking in the bottle of 1000mL of packing into, be added in the yeast strain of having cultivated 16h under 30 ℃, the yeast-inoculated amount is 10wt%, shaking bottle rotating speed is 200r/min, 30 ℃ of leavening temperatures, fermentation time 36h.
After testing, the content of gsh is 474mg/L.
Embodiment 3
As the embodiment 1 described method of utilizing the juice of sugar grass stalks glutathion production by fermentation, difference is:
Adopt the automatic fermenter of 10L, the liquid amount 5L of embodiment 1 described substratum, the yeast-inoculated amount is 10wt%, and leavening temperature is 30~32 ℃, and fermentation time is 36h, and the control saturation dissolved oxygen is 30%.Other conditions are with embodiment 1.With this understanding, the content of gsh is 685mg/L.
Embodiment 4
As the embodiment 1 described method of utilizing the juice of sugar grass stalks glutathion production by fermentation, difference is:
Bacterial classification: bread yeast (Saccharomyces cerevisiae) CICC1532 (preservation of Chinese industrial microbial strains preservation administrative center).
After testing, the content of gsh is 551mg/L.
Embodiment 5
As the embodiment 1 described method of utilizing the juice of sugar grass stalks glutathion production by fermentation, difference is:
Bacterial classification: the Angel high activity dried yeast, Angel Yeast Co.,Ltd produces, available from shop, square, Hua Lian, Jinan.
Take by weighing the commercially available Angel high activity dried yeast of 100g, put in 10 times 35 ℃ the 2wt% glucose solution, place 35 ℃ of thermostat container 20min after, move in 30 ℃ of thermostat containers and activate 2h, make yeast count reach 5 * 10
8Individual/more than the mL.
After testing, the content of gsh is 548mg/L.
Embodiment 6
As the embodiment 1 described method of utilizing the juice of sugar grass stalks glutathion production by fermentation, difference is:
Bacterial classification: produce gastral cavity candiyeast (Candida utilis) CICC1807 (preservation of Chinese industrial microbial strains preservation administrative center).
To produce gastral cavity candiyeast (Candida utilis) CICC1807 and be inoculated on the slant medium and activate, cultivate 36h for 28 ℃.Scrape from the test tube slant and to get a transfering loop yeast strain and insert the 10mL liquid seed culture medium test tube, at 28 ℃ of static cultivation 24h down.Be linked into the 100mL liquid seed culture medium with the 10wt% inoculum size, 28 ℃, shaking bottle rotating speed is 200r/min, cultivates 20h.
After testing, the content of gsh is 536mg/L.
Comparative Examples 1:
This Comparative Examples is except fermention medium component difference, and other conditions are all identical with embodiment 1.
This Comparative Examples fermention medium component is (g/L): glucose 50, yeast extract paste 15, (NH
4)
2SO
410, KH
2PO
412, K
2SO
44, MgSO
41.5, FeSO
40.008, MnSO
40.008, CuSO
40.01, ZnSO
40.01, CaCl
20.01.
After testing, the content of gsh is 542mg/L.
In Comparative Examples, the content of glucose is 50g in every liter of substratum, and the price of crude dextrose is 4.5 yuan/kg, and then the cost of glucose is 0.225 yuan in every liter of substratum, and the raw materials cost of the relative glucose of gsh is for being 0.415 yuan of every gram.
In embodiment 1 and Comparative Examples 1, the culture condition of yeast is identical, and artificial and other expense that consumes is also basic identical, and difference is both medium components.Comparative Examples 1 is only being calculated under the glucose condition of cost, the raw materials cost of the relative glucose of gsh is 0.415 yuan of every gram, and the cost of making raw material with the bright stalk juice of sweet sorghum is 0.296 yuan of every gram, and the raw materials cost that namely utilizes juice of sugar grass stalks to produce gsh wants Billy to hang down 40.2% with dextrose culture-medium.