Classifications

• • 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
  • C12N1/00—Microorganisms, e.g. protozoa; 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
  • C12N1/04—Preserving or maintaining viable microorganisms
• • 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
  • C12N1/00—Microorganisms, e.g. protozoa; 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
  • C12N1/005—Microorganisms, e.g. protozoa; 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 after treatment of microbial biomass not covered by C12N1/02 - C12N1/08

Definitions

• the invention relates to a process for the preparation of active dried microorganisms, and more particularly of active dried yeast, such as baker's yeast, brewer's yeast, wine yeast and the like.
• active dried yeast such as baker's yeast, brewer's yeast, wine yeast and the like.
• processes for the drying of yeast are known in general.
• the British Patent Specification no.1.132.793 discloses the drying of compressed yeast, i.e. a yeast having a dry matter content of about 30%, in a fluidized bed.
• British Patent Specification no. 1.230.205 discloses a similar process, relating to the preparation of dry baker's yeast of a high protein content.
• compressed mass of microorganisms is meant a mass of microorganisms, obtained by means of fermentation, from which the accompanying liquid has been removed as far as possible by mechanical means, such as filtration, centrifugation etc.
• yeast a so cabled compressed yeast having a dry matter content varying between 25 and 50% and more specifically between 30 and 40%, is obtained in this way.
• Saccharide disclosed in the British Patent Specification no. 763-926, may be suitably applied.
• the process of the present invention characterized by a drying period in the evacuated space of from 2.5 to 40 hours and more usually from 5—20 hours, which is dependent on the desired dry matter content, the expensive preparation of dry air, which should normally be necessary for the final stage of the drying process, is avoided.
• the present process is much more advantageous than in the case, wherein the complete drying process should be carried out in an evacuated space, because for the initial stage of the drying process the use of moist air is still possible and because the vacuo pumps can be much smaller and less energy consuming than would be necessary for the complete drying process under vacuo.
• the presently proposed process is particularly suitable for the preparation of active dried yeast (derived from a Saccharomyces cerevisiae strain), but may also be applied with good results on other types of yeast, such as brewer's yeast, wine yeast and the like or even on other kinds of microorganisms such as dried moulds and the like.
• the obtained mass is disintegrated, preferably by extruding the yeast through a perforated plate to form strands and breaking up the strands to form particles.
• the holes in the plate may have a cross section of 0.5-3 mm and preferably 1.2-1.6 mm, while after drying particles, having sizes of about 0.4-1.5 mm, are obtained.
• a surface active agent may be added to the material to be dried, in an amount of e.g. 0.5—5% and more particularly 1-2% by weight, calculated on dry matter.
• Suitable surface active agents are e.g. esters of saturated or unsaturated fatty acids and an alcohol, such as sorbitan raonolaurate, sorbitan monostearate, sorbitan raonooleate, glyceryl monostearate, glyceryl distearate, glyceryl monopalmitate, propylenej glycol monostearate or glyceryl mono- or drpalmitate or -stearate, wherein free hydroxy groups optionally have been esterified with a suitable acid for consumption, such as citric acid, tartaric acid, fumaric acid, malic acid, lactic acid and the like.
• a suitable acid for consumption such as citric acid, tartaric acid, fumaric acid, malic acid, lactic acid and the like.
• the load of the fluidized bed drying equipment is varying in amounts from 100-1000 kg/m 2 - floor area and preferably 400- 800 kg/m 2 and more preferably 600 kg/m 2 in general.
• the load of the fluidized bed drying equipment is about 600 kg/m 2 floor area, while open air is sucked, having a dew point of 10-30oC and more preferably of 15-25oC, while the air is filtered to obtain dust free air and is heated in a previous step to 90-120oC and more preferably about 110oC.
• the air space velocity in the fluidized bed will normally amount from 0.5—2.5 m/s and more generally 1.2 m/s, while the leaving air is almost saturated with water vapour and the relative humidity decreased in the final stage of drying.
• the air temperature is lowered at the end of the drying process as function of the actual bed temperature, being at most 35oC.
• the initial vacuum in the rotating vacuum drum is 10-20 mm Hg (1300-2600 Pa) while the pressure further decreases during this drying step to 10-2 mm Hg (1300-250 Pa).
• Biologically active dried microorganisms preferably dried active baker's yeast, prepared by the process of the invention, constitute further features of the invention. The following example illustrates a way in which the present invention can be carried into effect.
• Baker's yeast was prepared in the usual way, using molasses as nutrient. As phosphorus source ammoniumphosphate is used and as nitrogen source urea and ammonium sulphate were added. The obtained yeast showed a nitrogen content of 6.0-9.0% with several experiments, and 7.2% in general, calculated on dry matter.
• the phosphate content was 1.4-3.0% calculated on dry matter and in general 1.8%.
• the yeast was centrifugated and washed and was subsequently processed to a compressed yeast, showing a dry matter content of 30-36% and more preferably 34-35%, according to the method of the "Salz compiler" by means of socalled vacuumfilters.
• the load of the fluidized bed drying was 100-1000 kg/m 2 floor area and in general 600 kg/m . Open air showing a dew point of 13-24oC, was sucked. This air was filtered to dust free and heated in a heat exchanger up to 110oC. The space velocity of the air in the fluidized bed amounted from 0.8-2.0 m/s and in general 1.2 m/s. The leaving air was almost saturated with water vapour, while at the end of the drying, the relative humidity decreased. During the final part of this drying step, the air temperature was lowered as function of the actual bed temperature, whereby the bed temperature amounted to at most 35oC. After a drying period of 3 hours, a yeast was obtained, showing a dry matter content of 85-90%. The so obtained yeast particles were transmitted into a rotating vacuum drum for additional drying. The inner wall of the vacuo drum was corrugated in order to increase the heated area.

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• Life Sciences & Earth Sciences (AREA)
• Health & Medical Sciences (AREA)
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• Engineering & Computer Science (AREA)
• Organic Chemistry (AREA)
• Biotechnology (AREA)
• Zoology (AREA)
• Wood Science & Technology (AREA)
• Genetics & Genomics (AREA)
• Bioinformatics & Cheminformatics (AREA)
• Biomedical Technology (AREA)
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• Microbiology (AREA)
• Tropical Medicine & Parasitology (AREA)
• Medicinal Chemistry (AREA)
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• General Engineering & Computer Science (AREA)
• General Health & Medical Sciences (AREA)
• Sustainable Development (AREA)
• Micro-Organisms Or Cultivation Processes Thereof (AREA)
• Coloring Foods And Improving Nutritive Qualities (AREA)

Priority Applications (1)

Applications Claiming Priority (2)

Publications (1)

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ID=19834205

Family Applications (1)

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Cited By (7)

Citations (4)

• 1979
  • 1979-11-19 NL NL7908427A patent/NL7908427A/nl not_active Application Discontinuation
• 1980
  • 1980-11-05 PT PT72020A patent/PT72020B/pt unknown
  • 1980-11-13 MA MA19202A patent/MA19000A1/fr unknown
  • 1980-11-17 ZW ZW280/80A patent/ZW28080A1/xx unknown
  • 1980-11-17 ES ES496921A patent/ES496921A0/es active Granted
  • 1980-11-17 WO PCT/NL1980/000038 patent/WO1981001415A1/en not_active Ceased
  • 1980-11-17 EP EP80902356A patent/EP0040237A1/en not_active Withdrawn
  • 1980-11-18 BE BE0/202855A patent/BE886235A/fr unknown
  • 1980-11-18 GR GR63684A patent/GR71630B/el unknown
  • 1980-11-19 IT IT8068771A patent/IT8068771A0/it unknown
  • 1980-11-19 OA OA57253A patent/OA06654A/xx unknown

Patent Citations (4)

Non-Patent Citations (2)

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