Classifications

• • 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
  • C12P7/02—Preparation of oxygen-containing organic compounds containing a hydroxy group
  • C12P7/04—Preparation of oxygen-containing organic compounds containing a hydroxy group acyclic
  • C12P7/06—Ethanol, i.e. non-beverage
• • C—CHEMISTRY; METALLURGY
  • C12—BIOCHEMISTRY; BEER; SPIRITS; WINE; VINEGAR; MICROBIOLOGY; ENZYMOLOGY; MUTATION OR GENETIC ENGINEERING
  • C12N—MICROORGANISMS OR ENZYMES; COMPOSITIONS THEREOF; PROPAGATING, PRESERVING, OR MAINTAINING MICROORGANISMS; MUTATION OR GENETIC ENGINEERING; CULTURE MEDIA
  • C12N11/00—Carrier-bound or immobilised enzymes; Carrier-bound or immobilised microbial cells; Preparation thereof
  • C12N11/02—Enzymes or microbial cells immobilised on or in an organic carrier
  • C12N11/04—Enzymes or microbial cells immobilised on or in an organic carrier entrapped within the carrier, e.g. gel or hollow fibres
• • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
  • Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
  • Y02E50/00—Technologies for the production of fuel of non-fossil origin
  • Y02E50/10—Biofuels, e.g. bio-diesel

Definitions

• the present invention relates to a method of preparing ethanol by fermenting a lactose-containing solution with a lactase-containing microorganism.
• alcoholic beverages by fermenting lactose, i.e. milk sugar, has been known from time immemorial. Such a fermentation allows an immediate achievement of alcohol percentages of up to 3.0%, and through distillation the alcoholic strength may be increased.
• the article "Alkoholher ein aus MoIke” in the periodical "Die Branntwein ocean", from December 1977 discloses a method of preparing ethanol from whey.
• a selected species of yeast Saccharomyces fragilis
• whey permeate from an ultra-filtration plant also being added to said fermenter.
• an overflow is established to the second fermenter, and after filling this second fermenter a draining off to a separator is initiated.
• Part of the separated yeast float is returned to the first fermenter, whereas the wort freed from yeast is carried to a distilling plant through a buffer tank, the alcohol being continuously distilled in said plant.
• the yeast species Saccharomyces fragilis is used in concentrations of 2 to 4 g of dry ferment per liter of fermenting wort and a lactose concentration in the whey permeate of 5 to 9% of lactose anhydrate.
• the fermentation is carried out at a temperature of 25 to 30°C and a pH of 3.7 to 4.2.
• this fermenting process can only proceed continuously for up to 1 week since the lactose-containing medium is easily infected with microorganisms influencing the fermentation in an undesired manner.
• This feature especially applies to the use of Saccha romyces fragilis, which compared to the majority of other Saccharomyces species is especially sensitive to infection.
• Saccharomyces fragilis is used by the known method for the known whey fermentation in spite of the particularly high sensitivity thereof to infection because of its capability partly of cleaving lactose and partly of fermenting both the galactose and the glucose formed by the cleaving of lactose.
• the known method thus allows conversion velocities of lactose into ethanol of 1 to 5 ⁇ of lactose per g of dry ferment per hour.
• the yield of the process corresponds to 75-80% of the yield theoretically obtainable, i.e. that approximately 80% of the lactose is converted into ethanol, whereas the remaining lactose is lost as a consequence of growth of yeast, side reactions and said infection.
• the present invention relates to a method of fermenting ethanol by fermenting a lactose-containing solution with a lactase-containing microorganism, said method being characterised by using the microorganism in immobilised form.
• the immobilisation of microorganisms is known per se and is for instance performed by encapsulating microorganisms in a polymer.
• Polyacrylamide is one of the most used polymers, but it suffers from the disadvantage that the polymerisation is difficult to perform whilst maintaining the vitality of the immobilised microorganism.
• the monomer used for the immobilisation is toxic.
• the immobilisation of microorganisms by means of these substances may be carried out by initially mixing an aqueous solution of the polymer carbohydrate and the microorganisms and subsequently causing a formation of gel from the resulting mixture, e.g. through cooling or through contacting with cations such as potassium ions, ammonium ions, calcium ions, magnesium ions, stanno ions, ferri ions or aluminium ions.
• cations such as potassium ions, ammonium ions, calcium ions, magnesium ions, stanno ions, ferri ions or aluminium ions.
• the immobilisation may for instance be carried out by transferring the mixture of carbohydrate and microorganisms dropwise to an aqueous solution containing one of the ions causing formation of gel. As a result, guttiform solid particles containing microorganisms are obtained.
• the invention it turned out to be possible to immobilise lactase-containing microorganisms in such a manner that the immobilised cells may be used for fermenting lactose-containing solutions.
• the lactase-containing microorganisms through the immobilisation achieve a quite unusual resistance to infection.
• one or more microorganisms selected among Torula cremoris, Torula sphaerica, Torula lactosa, Saccharomyces fragilis, Saccharomyces lactis, and Candida pseudotrooicalis may be used.
• the microorganism Saccharomyces fragilis may be used for the method. It turned out surprisingly that the usually highly sensitive Saccharomyces fragilis may be immobilised by using carbohydrate-containing polymers whilst maintaining completely the vitality and capability of lactose—fermentation of the organism.
• An immobilised lactase-containing microorganism may therefore be used for a substantially longer period by the technical method than the corresponding non-immobilised mi ⁇ roorganismn.
• This feature is of particular importance to the fermentation of lactose-containing media, since the microorganisms used therefor are typically propagated to highest degree on a glucose-containing medium and therefore have an inducing period at the beginning of the fermentation. Thus typically 6 to 8 hours lapse from the time the microorganism is brought into contact with the lactose-containing medium, to the time the lactose fermentation occurs. This factor implies that the fermenting plant is unproductive in this period. An extension of the time of application of the microorganism therefore implies especially at lactose fermentations an increase of the productivity of the fermenting plant.
• the lactose-containing solution is ultrafiltrated whey.
• the fermenting is carried out by means of a single fermenter.
• the oxygen content in the draff from the whey fermen tations as conditioned by the biochemical oxygen consumption however becomes less than usual because less residues, dead cells, are present in the fermented product.
• a centrifugation of high liquid amounts is avoided by using immobilised yeast. This advantage is due to the above increase in productivity, which implies that the same productivity may be obtained by the method according to the invention compared to the use of the non-immobilised yeast. This is rendered possible by using a fermenting volume of about 1/5 to 1/10 of the volume used by the known technique.
• Molasses filled in bottles is inoculated with this culture by means of a platinum needle. After two days the content of the molasses bottles is transferred into two-liter Erlenmeyer flasks containing a liter of sterile nutrient solution of the following composition: 130 g of molasses
• the nutrient solution also used in the molasses bottles is sterilised before inoculation through autoclavering at 121oC for 30 minutes.
• the yeast is cultured at 30°C in said molasses bottles and Erlenmeyer flasks in a shaking thermostat. After 48 hours the molasses used is decanted off, whereafter the flasks are filled with fresh molasses (nutrient solution) . After 24 hours the operation is repeated, and the following day the produced yeast is harvested.
• the yeast is suspended in a volume of 3% of sodium alginate, and the mixture is transferred dropwise into a cold 0.1 molar solution of calcium chloride.
• the immobilised yeast is stored therein at 3oC for 24 hours.
• lactose-containing substrate a 9% by weight solution of lactose in water is used, and the fermentation is carried out in a thermostatically controlled fermenter provided with an overflow functioning at a volume of more than 1 liter.
• the total volume of the fermenter is 1 1/2 liter, and 0.5 liter of immobilised yeast corresponding to about 40 g of dry ferment is filled therein.
• the fermenting is carried out for 2 to 4 weeks whilst producing an amount of ethanol corresponding to 4.5% by volume determined through gas chromatography in the outlet of the fermenting unit.

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• Chemical & Material Sciences (AREA)
• Organic Chemistry (AREA)
• Engineering & Computer Science (AREA)
• Life Sciences & Earth Sciences (AREA)
• Zoology (AREA)
• Wood Science & Technology (AREA)
• Genetics & Genomics (AREA)
• Health & Medical Sciences (AREA)
• Bioinformatics & Cheminformatics (AREA)
• General Engineering & Computer Science (AREA)
• Biochemistry (AREA)
• Microbiology (AREA)
• General Health & Medical Sciences (AREA)
• Biotechnology (AREA)
• Chemical Kinetics & Catalysis (AREA)
• General Chemical & Material Sciences (AREA)
• Dispersion Chemistry (AREA)
• Biomedical Technology (AREA)
• Micro-Organisms Or Cultivation Processes Thereof (AREA)
• Preparation Of Compounds By Using Micro-Organisms (AREA)
• Immobilizing And Processing Of Enzymes And Microorganisms (AREA)

Applications Claiming Priority (2)

Publications (1)

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• 1980
  • 1980-05-12 DK DK206880A patent/DK206880A/da not_active Application Discontinuation
• 1981
  • 1981-05-08 NL NL8120168A patent/NL8120168A/nl unknown
  • 1981-05-08 AU AU71749/81A patent/AU7174981A/en not_active Abandoned
  • 1981-05-08 EP EP81901325A patent/EP0051653A1/en not_active Withdrawn
  • 1981-05-08 WO PCT/DK1981/000052 patent/WO1981003339A1/en not_active Application Discontinuation

Non-Patent Citations (1)

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