CA1170597A - Method for cultivating microorganisms, particularly yeasts, on lactoserum with an association of judiciously selected strains and of specific mutants of a strain - Google Patents
Method for cultivating microorganisms, particularly yeasts, on lactoserum with an association of judiciously selected strains and of specific mutants of a strainInfo
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- CA1170597A CA1170597A CA000388215A CA388215A CA1170597A CA 1170597 A CA1170597 A CA 1170597A CA 000388215 A CA000388215 A CA 000388215A CA 388215 A CA388215 A CA 388215A CA 1170597 A CA1170597 A CA 1170597A
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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
- C12P39/00—Processes involving microorganisms of different genera in the same process, simultaneously
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- 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
- C12N1/14—Fungi; Culture media therefor
- C12N1/16—Yeasts; Culture media therefor
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- 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
- C12N1/32—Processes using, or culture media containing, lower alkanols, i.e. C1 to C6
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Abstract
METHOD FOR CULTIVATING MICROORGANISMS, PARTICULARLY YEASTS, ON LACTOSERUM WITH AN ASSOCIATION OF JUDICIOUSLY SELECTED
STRAINS AND OF SPECIFIC MUTANTS OF A STRAIN
ABSTRACT OF THE DISCLOSURE
A method for cultivating microorganisms, particu-larly yeasts, on lactoserum uses, after separation of proteins and recovery of other components, an association of carefully selected strains, each of which is developing specifically on a given substrate naturally present in the medium or on meta-bolites formed during the fermentation process; and the process uses, moreover, specific mutants of a strain in order to create ecological "recesses" corresponding to an association of strains pertaining to the same species; the method allows the production of biomass or intermediate fermentation metabolites, usable in food industry.
STRAINS AND OF SPECIFIC MUTANTS OF A STRAIN
ABSTRACT OF THE DISCLOSURE
A method for cultivating microorganisms, particu-larly yeasts, on lactoserum uses, after separation of proteins and recovery of other components, an association of carefully selected strains, each of which is developing specifically on a given substrate naturally present in the medium or on meta-bolites formed during the fermentation process; and the process uses, moreover, specific mutants of a strain in order to create ecological "recesses" corresponding to an association of strains pertaining to the same species; the method allows the production of biomass or intermediate fermentation metabolites, usable in food industry.
Description
7(~597 BACKGROUND OF THE :rNVENTION
Field of the invention ______________________ The present invention relates to food industry and, more specifically, to a method for optimization o~
microorganism cultures, particularly yeast cultures, spe-cially lactic yeasts, for the production of biomass or of intermediate fermentation metabolites, usable in food indus-try.
Descri~tion of the ~rior art ______ ____________ _____ _ One of the known methods for cultivating lactic yeasts on lactoserum is disclosed in French pàtent No.1,128, 063 of Fromageries Bel society. It relates to a method for manufacturing burst lactic yeasts., which consists of sepa-rating through precipitation nitrogenous fermentable bodies, proteins and albumins, contained in the cheese-dairy or ca-! ~ein-factory serum or in the serum-buttermilk mixture, and of a~sorbing and converting by yeasts hydrocarbon bodies exi~ting in the thus deproteinated serum or mixture. Fermen-tation, run in precise pH, aeration and temperature condi-tions, is carried out by Saccharomycés strains, lately Glassified in the Kluyveromyces species (Lodder, 1970).
Since the filing date ~June 22, 1955) of French patent No. 1,128,063, this method has been the subject matter of many improvements, particularly as concerns the adaptation of cultures to new techniques for deproteination of lacto-serum, as well as conditioning and conservation of the thu~
obtained yeast cells. The deproteination of lactose, hereto-fore carried out by thermal precipitation, is now realized by ultrafiltration and ion exchange chromatography. Furthermore, the carbon substrate, heretofore composed of lactose, is now '~
.~ .~.
` ~17~597 composed of hydrolyzed lactose, such as indicated in French patent application publication No. 2,439,819 filed by Fromageries Bel society, wherein the culture of a micro-organism is run on the milk substrate comprising hydrolyzed lactose.
Presently, the production of food-yeast is based on the preferential culture of some strains on some media: for example, Kluyveromyces fragilis is cultivated on lactoserum, Candida lipolytica on alkanes, Candida tropicalis on gasoil and Candida utilis on molasses.
These fermentations, most often run in non sterile conditions, result in the presence, in the mixture, of other species, which, most often, are not desired.
Therefore, a resulting drawback is that the desired strain can be brought to be eliminated from the fermentor by a "contaminating pirate~ strain.
Moreover, if it is desired to obtain the development of a pure culture, it is necessary that the growth carbon substrate is of constant sterile quality so as to maintain a single fermentation strain. Now, lactoserums coming from the manufacture of lactic curd cheeses or of lactic casein ~acidic lactoserums) contain 4 to 10 g/l of lactlc acid, whereas lactoserums coming from the manufacture of rennet curd cheese or of rennet caseins ~mild lacto~erums) contain only 1 to 3 g/l of lactic acid, Moreover, the change in the lactic acid content of the substrate is also due to the fact that commercial units for lactoserum treatment receive this material to be treated continuously all day long and, as a function of its origin, this lactoserum has a lactic acid ratio which varies all day long.
In order to respond to the variation in this ratio, 117~597 it is necessary to devise a system able to adapt to these va-riations by a selection of strains presenting a specificity for assimilating substrates. Such a specificity, taking into account ~e diauxy phenomena existin~ in a continuous culture, can be considered only by the selection of mutants which will have lost the capacity of assimilating the one or the other one of the present carbon substrates. By the term "diauxy", it should be understood the capacity of adaptation of a strain to the consumption of various substrate~ the one~after the other one, which imposes the selection between limited growth veloci-ties so as to consume'all the carbon sources of fast growth velocities and a loss of carbon substances.
The increase in the growth velocity of a culture wherein there is a specificity of consumption of one species with respect to a substrate is in fact translated by the satu-ration of the'oxydative metabolism of Kluyveromyces and a por-tion of the carbon source i5 downgraded by a fermentary way, which leads to the compulsory appearance of ethanol. This etha-j nol is known as a toxic metabolite for the cells; therefore, its presence results in an inhibition of the yeast growth. Con-sequently, there'is a lim$tation in the concentration of this met'abolite'in ~his medium. It is therefore compulsory, in order to impose maximum growth velocities, to remove this metabolite;
now, it represents a synthesis potentiality: A judicious way of taking aavantage of this potentiality consists of introducing a strain able'to assimilate'this substrate, in a specific way.
It would be therefore useful to cope with the draw-backs of the usual method and to bring a solution to the herein-before disclosed problems. An object of the present invention is to allow the optimization of culture conditions on a lactic 1~7(~;597 substrate, by using presently known culture techniques, and, particularly, by using the opportunity of having mixed cultures such as disclosed in an article of ~arrisson P. E. called "Mixed .
cultures in industrial fenmentation"'tAdvances in Applied Mic~obiology (1978), 24, p. 129-164J which gives an example of mixed cultures on methane and methanol. The use of mixed cul-tures allows an increase in performances by using aifferent substrates.
''SUMMARY'OF'THE'INVENTI'ON
An object of thé present'invention is to provide a method for cultivation with an association of strains, each of which will use a.different component of the medium, in an exclusivé way, which provides an absence of competition with re~pect to the''different other subst~ates of the medium.
Another object of the pre~s~n~ invention i~ to se-lect specific mutants of a strain for a substrate in order to create ecological "recesses", each "recess" corresponding to an association of strai.ns pertaining to the ~ame species, strains whi.ch will be'dependent upon the whole development of the cul-ture,' the'refore upon neighbouring "reces'ses".
Other objects will appear from the following spe-cification.
''DETAILED'DESCRIPTION'OF THE INVENTION
Thes'e ob~ects are now met by a method for cultiva-ting microorganisms, particularly yeasts, on lacto~erum as a starting substrate,' method wherein, after separation of pro-teins contained in lactoserum and recovery of other components, the culture is carried out on the thus obtained lactic substrate, by using, on one hand, an association of judiciously selected ~7~597 strains, each of which is developing in a specific way on a given substrate naturally present in the medium or on metabo-lites'for~edduring the fermehtation process and, on the other hand, specific mutants of a strain so as to create ecological ~recesses" corresponding to an association of strains pertai-ning to the same species.
In the present invention, the culture media are lactoserums coming from different milk and cheese treatments, that is to say mild or acidic lactoserums, partially or wholly deproteinatea by several known processes which can be used commercially (precipitation t~rough thermal treatment, separa-tion through ultrafiltration, exclusion and ion exchange chro-matography, and so on) and'partially or wholly hydrolyzed through an enzymatic way ttreatment with a ~ -galaotosidase) or a chemical way.
Whatever the original culture medium may be, it consists always, on one hand, of lactose (or a mixture of glucose, galactose and lactose in the'case of a hydrolyzed lactose) and, on the'other hand, of lactic acid and other o~ganic acids. The proportion of both of these substrate categories can vary accor-ding to the origin and the technology used for obtaining the medium.
In the'method of the present in~ention, several strains with high performances as concern~ their growth rate or the protein yield of their composition and their specificity to grow on a sub~trate'are selected, and they are associated with a view to cultivate them on each of the carbon substrates pre-sent even in a small amount in the starting natural material or on metabolites formed during t~e ferme~tion ~ess. After s'ome time,' a very stable flora balance is resulting, the proportion 1~7~S97 of the various species depending upon the concentration of the substrates the ones with respect to the other ones.
In order to operate in an optimum way, such a system requires ecological "recesses~. ~ithin each of them, there exists a competition between various strains able to grow with variable veIocities on the single present substrate.
It is ~bvious that the selec'tions within each of the "recesses"
are depending the onesupon the'other ones, particularly for the "éthanol" recess, the substrate concentration of which is depending upon the'fermentary activity of strains pertaining to both of the other "recesses'l'tlactose and its hydrol~ysis derivatives: lactic acid and other organic acids) and, par-ticularly, to the ~lactose"' recess. ' The'selected strains pertain particularly to the following species : KI~eromyces fragilis, Xluyveromyces lactis and Torulopsi~ bovina. Kluyver'omyces fragilis are developing on lactose, Kluyve~n~ces' lactis on lactic acid, without any possi-bility of interferences, and Tbrulopsis bovina on ethanol. The balance between strains is varying according to the proportion of substrates'in the'medium and the 'capacity of the fermentor for the'produced ethanol amount.
As an example, the'following distribution in a medium consisting of lactose,' lactic acid and ethanol consisting of 90-95% of lactoserum, 5-10% of lactic acid and 1-3~ of etha-nol can be given :
- Kluyveromyces fragilis : about 90 to gS%
- Kluyveromyces lactis : about 5 to 10%
- Torulopsis bovina : about 1 to 3~
If this medium i~ partially or wholly hydrolyzed lactoserum, which results in the presence of two additional 1~7~S97 carbon substrates, glucose ana galactose, it may be interes-ting to use a new yeast strain such as Saccharomyces cerevisae or Candida utilis. It should be noted that the hydrol~sis rate of lactose can vary between 0 and 100~, the distribution of glucose and galactose between 0 and 45% and that-of ~actosb-hetween 0 and 95~.
The strain balance, which varies as a function of the substrate nature,' is the following one, when there is hydrolysis of lactose up to 80-90~ and the substrates are con-sisiing of 10-20% of lactose, 36-43% of glucose, 36-43% of ga-lactose, 5-10% of lactic acid and 1-3% of ethanol :
- Kluyveromyces fragilis : about 4~ to 65 - Kluyveromyces lactis : about 5 to 10 %
- Canaida utilis : about 35 to 45 %
- Torulopsis bovina : about 1 to 3 %
The used fermentors are operating, in optimum conditions, at temperatures comprised between about 30 and 40C, at a pJ~ of about 3 to 4, with an inlet air flow rate equal to about 1300 m3~hr, with a range of about 2 to 3 billions of to-tal cells per cm3, this rate being the same whatever the strain.It should be'noticed that the air volume being always a function of the medium volume, the one of 1800 m3thr corresponds to a medium volume of 25m3. By expressing the air volume not in m3thr but in W m (air volume~medium volume~min~, the optimum condi-tions are'located between 1.2 and 1.5. As a continuous work isc~rried out, the''flow rate is constant during the fermentation and before tapping.
The biomass and~or metabolite 'yield can be increased by incorporating within the'culture medium inorganic substances such as phosphorus, copper, zinc, iron and many other elements which are nutritive substances for microorganisms tH3Po CuSO4,ZnSO4,FeSO4 addition).
- With respect to the presently existing culture methods, with a single primordial strain and with parasitical secondary strains, the method of the present invention has the following advantages : ~
1 - It is possible to adapt the methoa to different lactose~lactic acid ratios existing in lactoserums, which are the culture natural occurring media.
Field of the invention ______________________ The present invention relates to food industry and, more specifically, to a method for optimization o~
microorganism cultures, particularly yeast cultures, spe-cially lactic yeasts, for the production of biomass or of intermediate fermentation metabolites, usable in food indus-try.
Descri~tion of the ~rior art ______ ____________ _____ _ One of the known methods for cultivating lactic yeasts on lactoserum is disclosed in French pàtent No.1,128, 063 of Fromageries Bel society. It relates to a method for manufacturing burst lactic yeasts., which consists of sepa-rating through precipitation nitrogenous fermentable bodies, proteins and albumins, contained in the cheese-dairy or ca-! ~ein-factory serum or in the serum-buttermilk mixture, and of a~sorbing and converting by yeasts hydrocarbon bodies exi~ting in the thus deproteinated serum or mixture. Fermen-tation, run in precise pH, aeration and temperature condi-tions, is carried out by Saccharomycés strains, lately Glassified in the Kluyveromyces species (Lodder, 1970).
Since the filing date ~June 22, 1955) of French patent No. 1,128,063, this method has been the subject matter of many improvements, particularly as concerns the adaptation of cultures to new techniques for deproteination of lacto-serum, as well as conditioning and conservation of the thu~
obtained yeast cells. The deproteination of lactose, hereto-fore carried out by thermal precipitation, is now realized by ultrafiltration and ion exchange chromatography. Furthermore, the carbon substrate, heretofore composed of lactose, is now '~
.~ .~.
` ~17~597 composed of hydrolyzed lactose, such as indicated in French patent application publication No. 2,439,819 filed by Fromageries Bel society, wherein the culture of a micro-organism is run on the milk substrate comprising hydrolyzed lactose.
Presently, the production of food-yeast is based on the preferential culture of some strains on some media: for example, Kluyveromyces fragilis is cultivated on lactoserum, Candida lipolytica on alkanes, Candida tropicalis on gasoil and Candida utilis on molasses.
These fermentations, most often run in non sterile conditions, result in the presence, in the mixture, of other species, which, most often, are not desired.
Therefore, a resulting drawback is that the desired strain can be brought to be eliminated from the fermentor by a "contaminating pirate~ strain.
Moreover, if it is desired to obtain the development of a pure culture, it is necessary that the growth carbon substrate is of constant sterile quality so as to maintain a single fermentation strain. Now, lactoserums coming from the manufacture of lactic curd cheeses or of lactic casein ~acidic lactoserums) contain 4 to 10 g/l of lactlc acid, whereas lactoserums coming from the manufacture of rennet curd cheese or of rennet caseins ~mild lacto~erums) contain only 1 to 3 g/l of lactic acid, Moreover, the change in the lactic acid content of the substrate is also due to the fact that commercial units for lactoserum treatment receive this material to be treated continuously all day long and, as a function of its origin, this lactoserum has a lactic acid ratio which varies all day long.
In order to respond to the variation in this ratio, 117~597 it is necessary to devise a system able to adapt to these va-riations by a selection of strains presenting a specificity for assimilating substrates. Such a specificity, taking into account ~e diauxy phenomena existin~ in a continuous culture, can be considered only by the selection of mutants which will have lost the capacity of assimilating the one or the other one of the present carbon substrates. By the term "diauxy", it should be understood the capacity of adaptation of a strain to the consumption of various substrate~ the one~after the other one, which imposes the selection between limited growth veloci-ties so as to consume'all the carbon sources of fast growth velocities and a loss of carbon substances.
The increase in the growth velocity of a culture wherein there is a specificity of consumption of one species with respect to a substrate is in fact translated by the satu-ration of the'oxydative metabolism of Kluyveromyces and a por-tion of the carbon source i5 downgraded by a fermentary way, which leads to the compulsory appearance of ethanol. This etha-j nol is known as a toxic metabolite for the cells; therefore, its presence results in an inhibition of the yeast growth. Con-sequently, there'is a lim$tation in the concentration of this met'abolite'in ~his medium. It is therefore compulsory, in order to impose maximum growth velocities, to remove this metabolite;
now, it represents a synthesis potentiality: A judicious way of taking aavantage of this potentiality consists of introducing a strain able'to assimilate'this substrate, in a specific way.
It would be therefore useful to cope with the draw-backs of the usual method and to bring a solution to the herein-before disclosed problems. An object of the present invention is to allow the optimization of culture conditions on a lactic 1~7(~;597 substrate, by using presently known culture techniques, and, particularly, by using the opportunity of having mixed cultures such as disclosed in an article of ~arrisson P. E. called "Mixed .
cultures in industrial fenmentation"'tAdvances in Applied Mic~obiology (1978), 24, p. 129-164J which gives an example of mixed cultures on methane and methanol. The use of mixed cul-tures allows an increase in performances by using aifferent substrates.
''SUMMARY'OF'THE'INVENTI'ON
An object of thé present'invention is to provide a method for cultivation with an association of strains, each of which will use a.different component of the medium, in an exclusivé way, which provides an absence of competition with re~pect to the''different other subst~ates of the medium.
Another object of the pre~s~n~ invention i~ to se-lect specific mutants of a strain for a substrate in order to create ecological "recesses", each "recess" corresponding to an association of strai.ns pertaining to the ~ame species, strains whi.ch will be'dependent upon the whole development of the cul-ture,' the'refore upon neighbouring "reces'ses".
Other objects will appear from the following spe-cification.
''DETAILED'DESCRIPTION'OF THE INVENTION
Thes'e ob~ects are now met by a method for cultiva-ting microorganisms, particularly yeasts, on lacto~erum as a starting substrate,' method wherein, after separation of pro-teins contained in lactoserum and recovery of other components, the culture is carried out on the thus obtained lactic substrate, by using, on one hand, an association of judiciously selected ~7~597 strains, each of which is developing in a specific way on a given substrate naturally present in the medium or on metabo-lites'for~edduring the fermehtation process and, on the other hand, specific mutants of a strain so as to create ecological ~recesses" corresponding to an association of strains pertai-ning to the same species.
In the present invention, the culture media are lactoserums coming from different milk and cheese treatments, that is to say mild or acidic lactoserums, partially or wholly deproteinatea by several known processes which can be used commercially (precipitation t~rough thermal treatment, separa-tion through ultrafiltration, exclusion and ion exchange chro-matography, and so on) and'partially or wholly hydrolyzed through an enzymatic way ttreatment with a ~ -galaotosidase) or a chemical way.
Whatever the original culture medium may be, it consists always, on one hand, of lactose (or a mixture of glucose, galactose and lactose in the'case of a hydrolyzed lactose) and, on the'other hand, of lactic acid and other o~ganic acids. The proportion of both of these substrate categories can vary accor-ding to the origin and the technology used for obtaining the medium.
In the'method of the present in~ention, several strains with high performances as concern~ their growth rate or the protein yield of their composition and their specificity to grow on a sub~trate'are selected, and they are associated with a view to cultivate them on each of the carbon substrates pre-sent even in a small amount in the starting natural material or on metabolites formed during t~e ferme~tion ~ess. After s'ome time,' a very stable flora balance is resulting, the proportion 1~7~S97 of the various species depending upon the concentration of the substrates the ones with respect to the other ones.
In order to operate in an optimum way, such a system requires ecological "recesses~. ~ithin each of them, there exists a competition between various strains able to grow with variable veIocities on the single present substrate.
It is ~bvious that the selec'tions within each of the "recesses"
are depending the onesupon the'other ones, particularly for the "éthanol" recess, the substrate concentration of which is depending upon the'fermentary activity of strains pertaining to both of the other "recesses'l'tlactose and its hydrol~ysis derivatives: lactic acid and other organic acids) and, par-ticularly, to the ~lactose"' recess. ' The'selected strains pertain particularly to the following species : KI~eromyces fragilis, Xluyveromyces lactis and Torulopsi~ bovina. Kluyver'omyces fragilis are developing on lactose, Kluyve~n~ces' lactis on lactic acid, without any possi-bility of interferences, and Tbrulopsis bovina on ethanol. The balance between strains is varying according to the proportion of substrates'in the'medium and the 'capacity of the fermentor for the'produced ethanol amount.
As an example, the'following distribution in a medium consisting of lactose,' lactic acid and ethanol consisting of 90-95% of lactoserum, 5-10% of lactic acid and 1-3~ of etha-nol can be given :
- Kluyveromyces fragilis : about 90 to gS%
- Kluyveromyces lactis : about 5 to 10%
- Torulopsis bovina : about 1 to 3~
If this medium i~ partially or wholly hydrolyzed lactoserum, which results in the presence of two additional 1~7~S97 carbon substrates, glucose ana galactose, it may be interes-ting to use a new yeast strain such as Saccharomyces cerevisae or Candida utilis. It should be noted that the hydrol~sis rate of lactose can vary between 0 and 100~, the distribution of glucose and galactose between 0 and 45% and that-of ~actosb-hetween 0 and 95~.
The strain balance, which varies as a function of the substrate nature,' is the following one, when there is hydrolysis of lactose up to 80-90~ and the substrates are con-sisiing of 10-20% of lactose, 36-43% of glucose, 36-43% of ga-lactose, 5-10% of lactic acid and 1-3% of ethanol :
- Kluyveromyces fragilis : about 4~ to 65 - Kluyveromyces lactis : about 5 to 10 %
- Canaida utilis : about 35 to 45 %
- Torulopsis bovina : about 1 to 3 %
The used fermentors are operating, in optimum conditions, at temperatures comprised between about 30 and 40C, at a pJ~ of about 3 to 4, with an inlet air flow rate equal to about 1300 m3~hr, with a range of about 2 to 3 billions of to-tal cells per cm3, this rate being the same whatever the strain.It should be'noticed that the air volume being always a function of the medium volume, the one of 1800 m3thr corresponds to a medium volume of 25m3. By expressing the air volume not in m3thr but in W m (air volume~medium volume~min~, the optimum condi-tions are'located between 1.2 and 1.5. As a continuous work isc~rried out, the''flow rate is constant during the fermentation and before tapping.
The biomass and~or metabolite 'yield can be increased by incorporating within the'culture medium inorganic substances such as phosphorus, copper, zinc, iron and many other elements which are nutritive substances for microorganisms tH3Po CuSO4,ZnSO4,FeSO4 addition).
- With respect to the presently existing culture methods, with a single primordial strain and with parasitical secondary strains, the method of the present invention has the following advantages : ~
1 - It is possible to adapt the methoa to different lactose~lactic acid ratios existing in lactoserums, which are the culture natural occurring media.
2 - The whole'of each carbon source is used with a limitation of lo~ses, whereby there is obtained an optimum yield, which is about 50 to 55~. In the absence of ethanol me tabolizing strain, the loss would have been at least equal to the Torulopsis bovina proportion, i.e. 2 to 3%.
3 - It is possible to work with maximum growth ve-locities of the main strains, due to the consumption by a third ~train of toxic intermediate metabolites, whereby there is ob-talned a maximum productivity of the whole device ~fermentor);
the productivity gain i8 about 15 to 20% with respect to the normal method with a single'primordial strain.
the productivity gain i8 about 15 to 20% with respect to the normal method with a single'primordial strain.
4 - The ~interrecess" rivalry (competition) is cancel'led, while maintaining, on one'hand, rivalry inside each rec'ess and, on the other hand, rivalry of strain~ between re-cesses .
5 - The'plants are'not sophisticated as concerns aeration and the"'limitation of air-liquid transLers which are usually the 'factor limiting these'plants.
6 - The way of running operations is simplified.
The method of thé present invention allows the production of biomass ~food-yeast) and/or intermediate metabolites.
117C~S97 The present invention will now be aisclosea with the aia o~ the following examples which are given only as an illustration ana not a limitation of the present invention.
EXAMPL~ 1 :
A mild lactoserum is used, coming from a cheese-dairy, this lactoserum being deproteinatea by ultrafiltration.
This deproteinated lactoserum is sent to a so-callea Airlift fermentor working in the following conditions :
- Useful volume : 23 m3 - - Flow rate : 7600 l/hr - pH : 3 to 4 - Temperature - : 30 to 40C
- Air flow rate . : 1800 m3/hr - Addition of a nitrogenous source : NH4OH
The selectea strains are the following ones, with the hereinbelow indicated balance :
- Xluyveromyces fragilis on lactose : 90-96 ~
- ~luyveromyces lactis on lactic acid : 5-10 %
- Torulopsis bovina on ethanol : 1-3 %
Systematic controls, over two years, of the flora present in the medium have shown a.very stable distribution between the species.
~ EXAMPLE 2 An acidic lactoserum coming from a casein factory i8 used; this lactoserum has been deproteinated by ultrafiltra-tion and i.ts lactose ha~ been partially ~90%) hydrolyzed with the aid of a p-galactosidase~
The fermentation i8 carried out according to the same conditions as th.e ones given in example 1.
_ g _ .
~L~7C~5~7 The selected strains are the following o~es :
- Kluyveromyces fragilis on lactose and galactose - Kluyveromyces lactis on lactic acid - Candida utilis on glucose - Torulopsis bovina on ethanol.
The distribution of the strains is the following one :
- Kluyveromyces fragilis : 49.5 - 58.5 %
- Kluyveromyces lactis : 5 - 10 %
- Candidà utilis : 40 - 43 %
- Torulopsis bo~ina : 1 - 3 %
Systematic controls, over two years, of the flora present in the medium have shown a very stable distribution between the species.
Although the present specification relates to preferred embodiments it should be understood that the invention is not limited to said embodiments and include all modifications and developments within the scope of the appended claims.
_ lQ -
The method of thé present invention allows the production of biomass ~food-yeast) and/or intermediate metabolites.
117C~S97 The present invention will now be aisclosea with the aia o~ the following examples which are given only as an illustration ana not a limitation of the present invention.
EXAMPL~ 1 :
A mild lactoserum is used, coming from a cheese-dairy, this lactoserum being deproteinatea by ultrafiltration.
This deproteinated lactoserum is sent to a so-callea Airlift fermentor working in the following conditions :
- Useful volume : 23 m3 - - Flow rate : 7600 l/hr - pH : 3 to 4 - Temperature - : 30 to 40C
- Air flow rate . : 1800 m3/hr - Addition of a nitrogenous source : NH4OH
The selectea strains are the following ones, with the hereinbelow indicated balance :
- Xluyveromyces fragilis on lactose : 90-96 ~
- ~luyveromyces lactis on lactic acid : 5-10 %
- Torulopsis bovina on ethanol : 1-3 %
Systematic controls, over two years, of the flora present in the medium have shown a.very stable distribution between the species.
~ EXAMPLE 2 An acidic lactoserum coming from a casein factory i8 used; this lactoserum has been deproteinated by ultrafiltra-tion and i.ts lactose ha~ been partially ~90%) hydrolyzed with the aid of a p-galactosidase~
The fermentation i8 carried out according to the same conditions as th.e ones given in example 1.
_ g _ .
~L~7C~5~7 The selected strains are the following o~es :
- Kluyveromyces fragilis on lactose and galactose - Kluyveromyces lactis on lactic acid - Candida utilis on glucose - Torulopsis bovina on ethanol.
The distribution of the strains is the following one :
- Kluyveromyces fragilis : 49.5 - 58.5 %
- Kluyveromyces lactis : 5 - 10 %
- Candidà utilis : 40 - 43 %
- Torulopsis bo~ina : 1 - 3 %
Systematic controls, over two years, of the flora present in the medium have shown a very stable distribution between the species.
Although the present specification relates to preferred embodiments it should be understood that the invention is not limited to said embodiments and include all modifications and developments within the scope of the appended claims.
_ lQ -
Claims (9)
1. Method for cultivating microorganisms, and yeasts, on lactoserum as a starting substrate, wherein, after separa-tion of proteins contained in lactoserum and recovery of other components, the culture is carried out on the thus obtained lactic substrate, by using, on one hand, an assoc-iation of strains, each of which is developing specifically on a given substrate present naturally in the medium, or on metabolites formed during the fermentation process, and, on the other hand, specific mutants of a strain in order to create ecological "recesses" corresponding to an association of strains pertaining to the same species.
2. Method according to claim 1, wherein the association of strains consists of Kluyveromyces fragilis, developing on lactose, of Kluyveromyces lactis, developing on lactic acid, of Candida utilis and of Saccharomyces cerevisae, developing on glucose, and of Torulopsis bovina developing on ethanol.
3. Method according to claim 1, wherein the starting substrate is a mild or acidic lactoserum coming from various milk and cheese treatments.
4. Method according to claim 3, wherein the starting substrate is partially or wholly deproteinated by precipit-ation with the aid of thermal or acidic treatment, by separation through ultrafiltration or exclusion and ion exchange chromatography.
5. Method according to claim 3, wherein the starting substrate is also partially or wholly hydrolyzed enzymatic-ally or chemically.
6. Method according to any one of claims 1, 3, 5 wherein, the culture medium consists of a mixture of two or more substrates selected from the group consisting of lactose, lactic acid, ethanol and, galactose and glucose.
7. Method according to claim 1, wherein, inside each of the "recesses", a competition is maintained between different strains able to grow with the best yield on the single present substrate.
8. Method according to claim 7, wherein the selected strains pertain to species Kluyveromyces fragilis, Kluyveromyces lactis, Torulopsis bovina, Saccharomyces cerevisae or Candida utilis.
9. Method according to any one of claims 1, 2, 8, wherein the selected strains are microorganisms which have the ability of growing on the substrate or the substrates present in the medium, which are formed during the ferment-ation process.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| FR8022401A FR2492403A1 (en) | 1980-10-20 | 1980-10-20 | PROCESS FOR THE CULTURE OF MICROORGANISMS, PARTICULARLY YEAST, ON WHEY WITH A ASSOCIATION OF WELL-SELECTED STRAINS AND STRAIN-SPECIFIC MUTANTS |
| FR80/22401 | 1980-10-20 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1170597A true CA1170597A (en) | 1984-07-10 |
Family
ID=9247095
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA000388215A Expired CA1170597A (en) | 1980-10-20 | 1981-10-19 | Method for cultivating microorganisms, particularly yeasts, on lactoserum with an association of judiciously selected strains and of specific mutants of a strain |
Country Status (5)
| Country | Link |
|---|---|
| EP (1) | EP0050571B1 (en) |
| AT (1) | ATE6271T1 (en) |
| CA (1) | CA1170597A (en) |
| DE (1) | DE3162319D1 (en) |
| FR (1) | FR2492403A1 (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5486368A (en) * | 1992-05-28 | 1996-01-23 | Dmv Usa, Inc. | Production of a cultured yeast product from whey permeate, yeast cream and yeast centrate |
| CN101200733B (en) * | 2007-12-11 | 2010-12-08 | 天津科技大学 | Method for producing fuel ethanol by yeast hybrid fermentation whey |
Families Citing this family (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4595659A (en) * | 1983-10-20 | 1986-06-17 | Kraft, Inc. | Fermentation production of ascorbic acid from L-galactonic substrate |
| DD272182A3 (en) * | 1986-12-17 | 1989-10-04 | Leipzig Chemieanlagen | METHOD FOR OBTAINING HIGH QUALITY GOODS FROM WHEY |
| DE4447352C2 (en) * | 1994-12-20 | 1998-09-17 | Steripharm Pharmazeutische Pro | Process for the preparation of galactose-containing preparations for enteral and parenteral nutrition of patients |
Family Cites Families (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CH233548A (en) * | 1941-11-29 | 1944-08-15 | Ig Farbenindustrie Ag | Process for the production of yeast from solutions containing carbohydrates. |
| FR1002238A (en) * | 1946-08-22 | 1952-03-04 | Process for the direct manufacture of yeast extracts | |
| FR1128063A (en) * | 1955-06-22 | 1957-01-02 | Bel La Vache Qui Rit Fromage | Manufacturing process of lactic nutritional yeasts |
| US3818109A (en) * | 1971-03-19 | 1974-06-18 | Univ Kansas State | Conversion of whey solids to an edible yeast cell mass |
| GB1528011A (en) * | 1975-02-11 | 1978-10-11 | Shell Int Research | Continuous culture of micro-organisms |
| FR2439819A1 (en) * | 1978-10-24 | 1980-05-23 | Bel Fromageries | Foodstuff by fermentation of hydrolysed whey - after sepn. of protein, by yeasts, esp. Kluyveromyces fragilis |
-
1980
- 1980-10-20 FR FR8022401A patent/FR2492403A1/en active Granted
-
1981
- 1981-10-19 EP EP81401640A patent/EP0050571B1/en not_active Expired
- 1981-10-19 CA CA000388215A patent/CA1170597A/en not_active Expired
- 1981-10-19 DE DE8181401640T patent/DE3162319D1/en not_active Expired
- 1981-10-19 AT AT81401640T patent/ATE6271T1/en not_active IP Right Cessation
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5486368A (en) * | 1992-05-28 | 1996-01-23 | Dmv Usa, Inc. | Production of a cultured yeast product from whey permeate, yeast cream and yeast centrate |
| CN101200733B (en) * | 2007-12-11 | 2010-12-08 | 天津科技大学 | Method for producing fuel ethanol by yeast hybrid fermentation whey |
Also Published As
| Publication number | Publication date |
|---|---|
| DE3162319D1 (en) | 1984-03-22 |
| ATE6271T1 (en) | 1984-03-15 |
| EP0050571A1 (en) | 1982-04-28 |
| EP0050571B1 (en) | 1984-02-15 |
| FR2492403B1 (en) | 1983-09-23 |
| FR2492403A1 (en) | 1982-04-23 |
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