Composition to improve the biomass of lactic acid bacteria

Abstract

The present invention relates to a composition for increasing the biomass and viability of lactic acid bacteria. The present invention also relates to the use of said composition in culture media. For this purpose, the composition according to the invention is characterized in that it comprises a yeast extract where said yeast extract comprises at least 5.0% of true nucleosides by weight of dry product and at least 10.0% of potential nucleosides by weight of dry product.

Description

Title of the invention: Composition for improving the biomass of lactic acid bacteria Technical field

[0001] The present invention relates to a composition for increasing the biomass and viability of lactic acid bacteria. The present invention also relates to the use of said composition in culture media. Prior art

[0002] The ingestion of live microorganisms called "probiotics" is particularly beneficial in terms of health, in particular by promoting the proper functioning of the intestinal flora and the immune system. The concept of "probiotic" was defined in 2001 by the World Health Organization (WHO), it is "live microorganisms, which, when ingested in sufficient quantities, exert positive effects on health, beyond traditional nutritional effects". Lactic acid bacteria are among the main probiotics, in particular strains of the genus Lactobacillus and Bifidobacterium. They release lactic acid and bacteriocins in order to prevent bad bacteria from settling in the intestinal flora. Thus, they allow you to benefit from better intestinal comfort and fight against infections.They are found naturally in fermented foods such as yogurt, kefir, sauerkraut and sourdough.

[0003] Thus, there is a demand from the pharmaceutical and food industries to incorporate lactic acid bacteria into their final products. There also remains a demand from consumers who suffer from digestive discomfort and who wish to improve their immune defense in a natural way.

[0004] However, lactic acid bacteria are demanding microorganisms with regard to their nutritional needs. They are called "auxotrophic" because they do not have the capacity to synthesize certain nutrients necessary for their growth which must therefore be present in their growth medium. The formulation of the culture medium is one of the most important factors. Its composition will influence the growth of lactic acid bacteria. Thus, the absence or deficiency of one of the nutritional elements essential for their growth will negatively impact the growth yield of said bacteria.

[0005] Patent EP2251416 describes that the addition of compounds involved in the biosynthesis of nucleic acids makes it possible to improve the yield of lactic acid bacteria biomass in starter cultures and under conditions of high optical density. (greater than 10 at OD = 600 nm). Under this patent, the culture media used must contain at least one porphyrin molecule to improve oxygen transport. However, these molecules have the disadvantages of being very expensive and of being of animal origin. There remains a need to develop compositions that are both more economical and of non-animal origin to address societal concerns.

[0006] One of the objectives of the present invention is to propose a composition making it possible to improve the production of biomass of lactic bacteria economically and without raw material of animal origin. Summary of the invention

[0007] Surprisingly, the inventors have found that a composition comprising a yeast extract rich in nucleosides makes it possible to meet the nutritional needs of lactic bacteria and has the consequence of increasing their biomass.

[0008] An object of the present invention is to provide a composition for increasing the biomass of lactic acid bacteria characterized in that it comprises a yeast extract wherein said yeast extract comprises at least 5.0% of true nucleosides by weight of dry product and at least 10.0% of potential nucleosides by weight of dry product.

[0009] Generally speaking, yeast extracts are products known to those skilled in the art. According to the invention, the term "yeast extract" means the soluble fraction obtained after autolysis or enzymatic hydrolysis of yeast cells using endogenous or exogenous enzymes. The soluble fraction can also be obtained after plasmolysis or mechanical disruption of the yeast cells, according to known methods such as high-pressure homogenization, mechanical grinding, mechanical lysis using glass beads, ultrasonic disintegration, repeated freeze-thaw cycles or osmotic shock. Also according to the invention, the yeast extract is preferably the soluble fraction obtained after autolysis of said yeast cells, i.e. after enzymatic hydrolysis carried out solely by the endogenous enzymes of the yeast.Hydrolysis of yeast cells can also be achieved through exogenous enzymes, i.e. by adding additional enzymes, such as proteases. Yeast extracts obtained after enzymatic hydrolysis or autolysis are also called by those skilled in the art “yeast hydrolysate” or “yeast peptone”.

[0010] The yeast extract according to the invention can be obtained from any yeast. Preferably, the yeast strain used for the preparation of the extract according to the invention belongs to the genus Saccharomyces, Kluyveromyces or Candida (also known as Pichia or Lindnerd) and very particularly to the species Saccharomyces cerevisiae.

[0011] The term "nucleoside-rich yeast extract" means a yeast extract comprising at least 5.0% true nucleosides and at least 10.0% potential nucleosides by weight of dry product.

[0012] “Dry product” means a product having at least 94.0% dry matter.

[0013] Nucleic acids are linear polymers consisting of a chain of nucleotides. The nucleotides are linked to each other by phosphodiester bonds. Each nucleotide consists of a nitrogenous base associated with a pentose (5-carbon monosaccharide), namely a ribose for RNA or a deoxyribose for DNA, and a phosphate group. Similarly, each nucleotide consists of the association of a nucleoside and one to three phosphate groups linked by a phosphodiester bond to the pentose. The phosphodiester bond can be in the 5' or 3' position. In the context of the invention, the term "nucleotide" means monophosphate nucleotides, preferably 5'monophosphate nucleotides.

[0014] By definition, nucleosides consist of a nitrogenous base associated with a pentose (5-carbon ose), namely a ribose for RNA or a deoxyribose for DNA, linked by an N-glycosidic bond. The nitrogenous base can be a purine base (namely adenine, hypoxanthine or guanine) or a pyrimidine base (namely cytosine, thymine or uracil).

[0015] In particular, the nucleosides included in the composition according to the invention may have a purine base such as adenosine, deoxyadenosine, guanosine, deoxyguanosine and inosine or a pyrimidine base such as thymidine, deoxythymidine, uridine, deoxyuridine, cytidine and deoxycitidine.

[0016] For the purposes of the invention, the term “true nucleosides” corresponds to the sum of the nucleosides naturally present in the yeast extract, i.e. before any exogenous treatment with the yeast extract, such as hydrolysis for example. "Naturally present in yeast extract" also means free nucleosides, i.e. nucleosides present in monomeric form and before any exogenous treatment. Conversely, this definition does not include nucleosides naturally present in RNA, i.e. in the form of polymers, as well as nucleotides. and nitrogenous bases.

[0017] The yeast extract of the composition preferably comprises at least 5.0%, 5.5%, 6.0%, 6.5%, 7.0%, 7.5%, 8.0%, 8.5%, 9.0%, 9.5%, 10.0%, 10.5%, 11.0%, 11.5%, 12.0%, preferably at least 8.0%, most preferably at least 10.0% by weight of dry product of true nucleosides. The composition according to the invention comprises a yeast extract which comprises between 5.0 and 20.0% of true nucleosides by weight of dry product. Preferably, between 5.0 and 15.0%, more particularly between 8.0% and 11.0%.

[0018] For the purposes of the invention, the term "potential nucleosides" corresponds to the sum of all free and bound nucleotide compounds, such as nucleotides, nucleosides, free nitrogenous bases and in the form of polymers such as RNA, obtained after a treatment, for example of the hydrolysis type. The potential nucleosides are expressed as 5' monophosphate nucleotides (in 5'XMP equivalent) and as a percentage of dry product weight.

[0019] To calculate the rate of potential nucleosides, it is appropriate to convert the mass concentration of each nucleoside into the equivalent 5'XMP mass concentration, by applying the ratio of the molar mass of the corresponding nucleotide compound and the nucleoside of interest. The potential nucleoside rate is calculated by converting the total mass concentration of nucleosides into 5'XMP equivalent mass concentration.

[0020] The conversion calculation is as follows: -, . . , / - . , .r'vïrn'i , >adi^ûs?n;,b <M\r5'AjMP \undiKei<Mv,i5'UMP liitasiiieWriicSIMP Peanut nucleosides (SXMP equivalent) = - --+ + * uL. Where [nucleoside] corresponds to the mass concentration of the nucleoside of interest. Where Mw5'XMP corresponds to the molar mass of the associated 5'monophosphate nucleotide. Where Mw nucleoside corresponds to the molar mass of the nucleoside of interest, expressed in g / mol. The rate of potential nucleosides is necessarily higher than the rate of true nucleotides.

[0021] In the context of the invention, an acid hydrolysis is carried out on the yeast extract. This treatment makes it possible to convert all of the nucleotide compounds into nitrogenous bases. The nitrogenous bases generated are expressed in 5'monophosphate nucleotides and as a percentage of dry product weight, using a calculation which takes into account the respective molecular weights of the nitrogenous bases and the corresponding 5'monophosphate nucleotides.

[0022] The conversion calculation is as follows: nie'vi / n\ I itytMine^MwS CMP ( [ Nitrogenous bases equivalent 5 XMP = —-h-..—.— + ^——2-—----+ i———-— + sj —a. ....... V “ / Mv.cyttKiM- Mwg'Mtnitie Mwcuicnme SMiypoxanthiiu: Where [nitrogen base] corresponds to the mass concentration of the nitrogen base of interest. Where Mw5'XMP corresponds to the molar mass of the 5'monophosphate nucleotide associated with the nitrogenous base of interest. Where Mw nitrogenous base corresponds to the molar mass of the nitrogenous base of interest, expressed in g / mol.

[0023] The yeast extract of the composition preferably comprises at least 10.0%, at least 15.0%, preferably between 10.0% and 20.0% of potential nucleosides by weight of dry product.

[0024] The yeast extract rich in nucleosides can be obtained by methods known to those skilled in the art. Preferably, the nucleoside-rich yeast extract is obtained by applying a phosphoric-monoester hydrolase or phosphatase enzyme (EC 3.1.3) to a nucleotide-rich yeast extract. Preferably, the alkaline phosphatase enzyme is a nucleotidase (EC 3.1.3.1). The phosphatase hydrolyzes the phosphate groups of the nucleotides and thus releases the corresponding nucleosides. “A nucleotide-rich yeast extract” means a yeast extract that comprises at least 2.0% free nucleotides by weight of dry product. As a result, the nucleotides or RNA in the yeast extract are converted into nucleosides. In the context of the present invention, the term "nucleoside" refers to a building block of nucleic acids.

[0025] The yeast extract of the composition according to the invention comprises nucleosides which may be adenosine, deoxyadenosine, guanosine, deoxyguanosine, cytidine, deoxycitidine, thymidine, deoxythymidine, inosine, uridine, deoxyuridine or a mixture.

[0026] The term “mixture” means a yeast extract of the composition according to the invention which comprises at least two nucleosides present in the list above. Preferably, the yeast extract of the composition comprises at least nucleosides with a purine base. More preferably, the yeast extract of the composition comprises at least one nucleoside from guanosine and / or inosine. Preferably, the yeast extract comprises at least cytidine, uridine, inosine, guanosine and adenosine.

[0027] Advantageously, the composition according to the invention is free of exogenous nucleoside. The addition of nucleoside exogenously to the culture medium has the disadvantage of being expensive and of obtaining less biomass production compared to the presence of endogenous nucleosides. Thus, the composition according to the invention comprises endogenous nucleosides which are naturally present in the yeast extract.

[0028] By studying the nutritional needs of lactic acid bacteria, the inventors discovered that for their growth, they consume the nucleosides present in their environment and release them in the form of nitrogenous bases. Nucleosides are used by lactic acid bacteria as a carbon source. Thus, advantageously, the composition according to the invention makes it possible to provide the nutritional needs which are essential for the growth of lactic acid bacteria and therefore makes it possible to increase the biomass.

[0029] The term "lactic acid bacteria" means Gram-positive, anaerobic, partially oxygen-tolerant bacteria capable of producing lactic acid, in a strain-dependent manner, by homo- or heterofermentative fermentation of glucose. They are part of the phylum Firmicutes, the class Bacilli, and the order Lactobacillales. The taxon called lactic acid bacteria includes Gram-positive, non-spore-forming, anaerobic or facultatively aerobic cocci, bacilli, or coccobacilli with a percentage of guanosine and cytosine (G+C) of less than 50%. These bacteria are acidophilic with an optimal growth pH of between 3.5 and 6.5. Lactic acid bacteria include 13 genera and can be of the genera Lactobacillus, Bifi-dobacterium, Leuconostoc, Lactococcus, Enterococcus, Streptococcus, Pediococcus, Camobacterium, Oenococcus, Weissella, Aerococcus, Tetragenococcus and Vagococcus.Preferably, the lactic acid bacteria belong to the genus Lactobacillus, Bifi do-bacterium, Lactococcus, Tetragenococcus or Bacillus, and especially to the species Lactobacillus acidophilus or Bacillus sp.

[0030] The term “lactic acid bacteria biomass” means the total mass of living lactic acid bacteria in the culture medium.

[0031] The term "increasing the biomass of lactic acid bacteria" means an increase of at least +0.25 Log in the total mass of living lactic acid bacteria in the culture medium compared to the mass of lactic acid bacteria obtained under the culture conditions without the composition according to the invention.

[0032] The yeast extract within the meaning of the invention may also comprise amino acids as a source of nutrients which may be at least alanine, valine, leucine, isoleucine, methionine, phenylalanine, tryptophan, proline, serine, threonine, cysteine, tyrosine, asparagine, glutamine, aspartic acid, glutamic acid, lysine, arginine and histidine. Preferably, the yeast extract comprises tryptophan and / or asparagine, preferably tryptophan.

[0033] The composition according to the invention comprises a yeast extract which comprises at least 30.0% of total amino acids by weight of dry product. The composition according to the invention comprises a yeast extract which comprises between 30.0% and 70.0% of total amino acids by weight of dry product, preferably between 30.0% and 50.0%, more preferably between 40.0% and 50.0% of total amino acids by weight of dry product.

[0034] The yeast extract within the meaning of the invention may also comprise carbohydrates, lipids, minerals, vitamins, peptides and nucleotides which are essential nutrients for the growth of bacteria.

[0035] Another object of the invention is a method for increasing the biomass of lactic acid bacteria comprising the following steps: a. Have a culture medium, where said culture medium is free of porphyrin; b. Adding to the culture medium a composition comprising a nucleoside-rich yeast extract, wherein said yeast extract comprises at least 5.0% true nucleosides by weight of dry product and at least 10.0% potential nucleosides by weight of dry product; c. Incubation of lactic acid bacteria in said culture medium; d. Harvesting of the biomass of lactic bacteria obtained.

[0036] The culture medium used for the production of lactic acid bacteria is free of porphyrin. Surprisingly, the inventors discovered that the composition according to the invention made it possible to produce lactic acid bacteria in the absence of a dioxygen transporter in the culture medium.

[0037] The composition added in step b) makes it possible to provide the essential elements for the growth of lactic bacteria.

[0038] The composition added in step b) comprises a yeast extract which preferably comprises at least 5.0%, 5.5%, 6.0%, 6.5%, 7.0%, 7.5%, 8.0%, 8.5%, 9.0%, 9.5%, 10.0%, 10.5%, 11.0%, 11.5%, 12.0%, preferably at least 8.0%, most preferably at least 10% by weight of true nucleosides by weight of dry product. This composition according to the invention comprises a yeast extract which comprises between 5.0 and 20% of true nucleosides by weight of dry product. Preferably, between 5.0 and 15.0%, more particularly between 8.0% and 11.0% of true nucleosides by weight of dry product.

[0039] The composition added to the culture medium, in step b) comprises a yeast extract which comprises at least 10.0%, at least 15.0%, preferably between 10.0% and 20.0% by weight of potential nucleosides.

[0040] The culture medium used in the method according to the invention comprises between 0.5 g / L and 40 g / L of the composition added in step b), preferably between 10 g / L and 20 g / L.

[0041] Another object of the invention is the use of a composition comprising a yeast extract rich in nucleosides in a culture medium, preferably in a culture medium for lactic acid bacteria. Brief description of the drawings

[0042] The following examples and figures illustrate the invention and do not limit the scope of the invention as claimed:

[0043] [Fig-1] is a graph confirming the effects of a composition according to the invention on the growth of Lactobacillus acidophilus DSMZ 20242.

[0044] [Fig.2] is a graph confirming the effects of a composition according to the invention, on the biomass and viability after growth of a Lactobacillus acidophilus DSMZ 20242 strain compared to the reference product.

[0045] [Fig.3] is a graph showing the effect of a composition according to the invention compared to a reference product in the presence or absence of exogenous nucleosides on the growth and viability after growth of a Lactobacillus acidophilus DSMZ 20242 strain. The term "exogenous nucleosides" means nucleosides which have been added to the culture medium in pure form.

[0046] [Examples] Example 1: Example of increase in the biomass of Lactobacillus acidophilus DSMZ 20242.

[0048] In this example, the increase in the biomass of lactic bacteria thanks to a composition according to the invention was demonstrated for Lactobacillus acidophilus DSMZ 20242.

[0049] Compositions:

[0050] Two compositions comprising yeast extracts were prepared. The first composition (called the “nucleoside” prototype) is a composition according to the invention, comprising a yeast extract rich in nucleosides. The yeast extract of this prototype is prepared from a yeast strain of the species Saccharomyces ce-revisiae. The yeast extract of the “nucleoside” prototype is obtained after incubation of a NuCel® 582 yeast extract with an alkaline phosphatase enzyme. The second composition (called "NuCel® 582") is used as a comparative product and comprises a NuCel 582 yeast extract marketed by Procelys by Lesaffre. Unlike the yeast extract of the "nucleosides" prototype, the NuCel® 582 yeast extract has not been treated with an alkaline phosphatase enzyme.

[0051] Table 1 corresponds to the composition of the yeast extracts included in the different compositions are shown in Tables 2 and 3 below: [Tables 1] Yeast extract composition % (mass / mass) NuCel 582 “nucleoside” prototype (comparative) Free nucleotides (5'XMP) (g / 100g) 0.00% 6.71% True nucleosides (g / 100g) 9.48% 0.87% Potential nucleosides (expressed as 5'XMP) (g / 100g) 12.60% 1.16% Free nitrogenous bases (g / 100g) 0.27% 0.34% [Tables 2] Yeast extract composition % (mass / mass) Prototype* nucleosides » NuCel 582 (comparative) True cytidine (g / 100g) 1.64 0.02 True guanosine (g / 100g) 2.42 0.25 True inosine (g / 100g) 2.78 0.39 True uridine (g / 100g) 2.63 0.20 True adenosine (g / 100g) <0.001 0.02 Potential cytidine (expressed as 5'XMP -g / 100g) 2.18 0.03 Potential uridine (expressed as 5'XMP -g / 100g) 3.50 0.33 Potential inosine (expressed as 5'XMP -g / 100g) 3.57 0.42 Potential guanosine (expressed as 5'XMP-g / 100g) 3.14 0.25 Potential adenosine (expressed as 5'XMP-g / 100g) <0.001 0.02

[0052] Culture conditions for Lactobacillus acidophilus DSMZ 20242 The quantities of the components of the culture medium are listed in Table 3 below: [Tables 3] Components Concentration (g / L) Composition Prototype “nucleosides” or “NuCel 582” 10 Yeast extract “NuCel 581” 20 Sodium acetate 5 Ammonium citrate 2 Tween 80 1 ml K2HPO4 2 MgSO4 0.2 MnSO4 0.05 Glucose 20 Lactose 10

[0053] The culture conditions of Lactobacillus acidophilus DSMZ 20242 are shown in Table 4: [Tables4] Culture Conditions First pre-culture 37°C - 24h - bacterial inoculum 1.0% - DSMZ 20242 medium Second pre-culture 42°C - 24h - Bacterial inoculum D0(600nm) = 0.01 - DSMZ 20242 medium Main culture (in flask) 42°C - 18h - Bacterial inoculum 1.0% - DSMZ 20242 medium RESULTS

[0054] Example of growth of Lactobacillus acidophilus DSMZ 20242 in the medium described for this strain, in the presence or absence of a composition according to the invention.

[0055] [Fig. 1] shows the production kinetics of Lactobacillus acidophilus DSMZ 20242 for the two products tested: NuCel® 582 and the prototype nucleosides.

[0056] In the presence of the composition according to the invention (prototype), the growth of Lactobacillus acidophilus DSMZ 20242 is faster than with the reference product “NuCel® 582”. The maximum speed is reached approximately one hour earlier and the lag phase is shorter with the composition according to the invention. The prototype nucleosides also had a positive effect on the concentration of the strain Lactobacillus acidophilus DSMZ 20242.

[0057] [Fig.2] shows the effect of the prototype “nucleosides” on biomass and viability of Lactobacillus acidophilus DSMZ 20242. Bacterial biomass is expressed in Colony Forming Units (Log (CFU / mL)). Active fluorescent unit (AFU) also represents the number of “live and viable” probiotic bacteria. These units differ only in how they are measured. In these tests, the CFU was measured by spreading on an MRS agar (de Man, Rogosa, Sharpe), marketed by BioMérieux, at pH 6.2 and in anaerobic conditions and the AFU is measured by flow cytometry, the bacteria are marked with fluorescent "markers" Syto24-propidium iodide and counted by a laser as they pass through a tube. The percentage of viability is also measured by flow cytometry with Syto 24 - propidium iodide labeling. The results are from four biological replicates. The prototype “nucleosides” used is autoclaved or pasteurized. A significant increase in biomass production was observed for the Lactobacillus acidophilus DSMZ 20242 strain in the presence of the prototype composition "nucleosides" (autoclaved or pasteurized) compared to the reference product "NuCel® 582". In the presence of the pasteurized prototype "nucleosides", production increased by 0.35 log CFU / mL. A significant improvement in the viability percentage of the Lactobacillus acidophilus DSMZ 20242 strain was also observed in the presence of the “nucleoside” prototype compared to the reference product “NuCel® 582”. In the presence of the pasteurized “nucleoside” prototype composition, the total proportion of viable Lactobacillus acidophilus DSMZ 20242 bacteria was 88.6%, while in the presence of the reference product it was 51.8%. The same results are observed in the presence of the autoclaved “nucleoside” prototype and the pasteurized “nucleoside” prototype. Autoclaving and pasteurization have no impact on the increase in biomass production and on the viability of the Lactobacillus acidophilus DSMZ 20242 strain, therefore no impact on the quality and effectiveness of the composition according to the invention.

[0058] The inventors also compared the effect of adding adenosine to the culture medium ([Fig.3]) on the biomass production of Lactobacillus acidophilus DSMZ 20242. It is observed that the biomass production and the quantity of viable Lactobacillus acidophilus DSMZ 20242 bacteria are higher in the presence of a composition rich in nucleosides according to the invention (prototype nucleosides), only in the presence of adenosine and a reference product (NuCel® 582) in the culture medium.

[0059] The inventors tested the effect of adding exogenous nucleosides to the culture medium ([Fig.3]). Under standard conditions, the use of a “prototype nucleoside” composition alone made it possible to obtain better results on biomass production and viability for the strain Lactobacillus acidophilus DSMZ 20242 compared to the reference product alone or in combination with exogenous nucleosides.

Claims

Claims

1. Composition for increasing the biomass of lactic acid bacteria characterized in that it comprises a yeast extract wherein said yeast extract comprises at least 5.0% of true nucleosides by weight of dry product and at least 10.0% of potential nucleosides by weight of dry product.

2. Composition according to claim 1 characterized in that the yeast extract is obtained from a yeast strain of the genus Sac-charomyces, preferably Saccharomyces cerevisiae.

3. Composition according to one of claims 1 or 2, characterized in that the nucleosides are chosen from adenosine, deoxyadenosine, guanosine, deoxyguanosine, cytidine, inosine, deoxycitidine, thymidine, deoxythymidine, uridine, deoxyuridine or a mixture.

4. Composition according to claim 3 characterized in that said yeast extract comprises at least one nucleoside from guanosine and / or inosine.

5. Composition according to one of claims 1 to 4, characterized in that said yeast extract comprises at least 30.0% of total amino acids by weight of dry product.

6. Composition according to one of claims 1 to 5, characterized in that said yeast extract comprises between 30.0 and 70.0% of total amino acids by weight of dry product, preferably between 30.0% and 50.0%, more preferably between 40.0 and 50.0% of total amino acids by weight of dry product.

7. Composition according to one of claims 1 to 6, characterized in that the yeast extract comprises tryptophan and / or asparagine, preferably tryptophan.

8. Composition according to claims 1 to 6 characterized in that the lactic bacteria are of the genus Lactobacillus, Bifidobacterium or Bacillus.

9. Composition according to claim 8 characterized in that the lactic bacteria are of the species Lactobacillus acidophilus or Bacillus sp.

10. A method of increasing the biomass of lactic acid bacteria comprising the following steps: a. Providing a culture medium, wherein said culture medium is free of porphyrin; b. Adding to the culture medium a composition comprising a nucleoside-rich yeast extract, wherein said yeast extract comprises at least 5.0% true nucleosides by weight of dry product and at least 10.0% potential nucleosides by weight of dry product; c. Incubating the lactic acid bacteria in said culture medium; d. Harvesting the resulting lactic acid bacteria biomass.

11. Method for increasing the biomass of lactic acid bacteria according to claim 10, characterized in that the culture medium comprises between 0.5 g / L and 40 g / L of the composition added in step b), preferably between 10 g / L and 20 g / L.

12. Use of a composition as defined in claims 1 to 7 in a culture medium.

13. Use of a composition as defined in claim 12 in a culture medium for lactic acid bacteria.

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