CN111187738B - Streptococcus thermophilus for producing 2, 3-pentanedione and application of streptococcus thermophilus in preparation of soybean milk - Google Patents

Streptococcus thermophilus for producing 2, 3-pentanedione and application of streptococcus thermophilus in preparation of soybean milk Download PDF

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CN111187738B
CN111187738B CN202010086790.5A CN202010086790A CN111187738B CN 111187738 B CN111187738 B CN 111187738B CN 202010086790 A CN202010086790 A CN 202010086790A CN 111187738 B CN111187738 B CN 111187738B
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赵建新
刘小鸣
于朋
崔树茂
唐鑫
闫博文
陈卫
张灏
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Jiangnan University
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Abstract

The invention discloses streptococcus thermophilus for producing 2, 3-pentanedione and application thereof in preparing soybean milk, belonging to the technical field of microbiology. The streptococcus thermophilus CCFM1094 has the following properties: (1) the growth rate of the strain is high, the strain enters a stable period within 8 hours in an M17 culture medium, the increment of the number of viable bacteria within 9 hours in the soybean milk reaches 2 orders of magnitude, and the method is suitable for industrial fermentation; (2) the acid production rate of the strain is high, the pH of the fermented soybean milk is reduced to 4.59 after 9 hours, and the fermentation end point is reached, so that the production of curd and flavor substances is facilitated; (3) the strain has strong capability of producing 2, 3-pentanedione in fermented soybean milk, and can produce 116.73 mu g/kg in 9 hours. The streptococcus thermophilus CCFM1094 is used as a leaven to ferment the soybean milk, is beneficial to improving the milk flavor and the nut flavor of the fermented soybean milk, and has very wide application prospect in the preparation of the soybean milk.

Description

Streptococcus thermophilus for producing 2, 3-pentanedione and application of streptococcus thermophilus in preparation of soybean milk
Technical Field
The invention relates to streptococcus thermophilus for producing 2, 3-pentanedione and application thereof in preparing soybean milk, belonging to the technical field of microbiology.
Background
The soybean resources in China are rich, and the soybean food has high nutritive value and is favored by most people. Currently soy products mainly include non-fermented soy products and fermented soy products. The fermented soybean products, such as fermented soybean beverages and fermented sour soybean milk, have attracted much research interest, in addition to the traditional high-salt products such as fermented soybeans, soybean paste, fermented bean curd, soy sauce and the like, which are mainly used as main materials, and the novel fermented soybean products such as fermented soybean beverages and fermented sour soybean milk fermented by using lactic acid bacteria.
The flavor of sour soybean milk is an important part of the quality of the product and is a key factor for the acceptance of consumers. In recent years, the flavor of fermented soybean milk has been widely studied, and aldehydes, alcohols, ketones, acids, aromatic compounds and furans constitute the main flavor of sour soybean milk (Achouri A, Boye J I, Zamani Y. identification of flavor compounds in soy milk using solid-phase microextraction-gas chromatography [ J ]. Food Chemistry,2006, 99(4): 759-766.). 2, 3-pentanedione and 2, 3-butanedione are similar in flavor characteristics and formation routes, and present a 'cream and nut flavor', and Yuxing (research on fermented sour bean milk beverage [ D ]. tin-free: university of Jiangnan, 2005.) found in research that 2, 3-pentanedione and 2, 3-butanedione in ketones are main substances of sour bean milk, and their improvement can improve the flavor of sour bean milk.
In the fermentation of soybean milk, Streptococcus thermophilus and other bacilli such as Lactobacillus bulgaricus, Lactobacillus plantarum, Lactobacillus helveticus, etc. are mostly used at present to produce different flavors by complex fermentation in suitable proportions (Kaneko D, Igarashi T, Aoyama K. Reduction of the off-flavor producing by the yogurt starter culture enclosing Streptococcus thermophilus and Lactobacillus brevis subsp. bulgaricus in yeast [ J ] Journal of Agricural & Food Chemistry 2014,62(7): 1658-63.).
However, since soybean milk contains a certain amount of sucrose, stachyose and raffinose, many fermentation strains cannot well utilize sugars in soybean milk, and fermented soybean milk often has beany flavor, and the prepared soybean milk has poor flavor.
Different lactic acid bacteria are selected to ferment the soybean milk in the fermentation process, and the flavor components generated by metabolism of the soybean milk have large difference (the influence of the lactobacillus on the flavor and the antioxidant activity of the fermented soybean milk is researched [ D ]. Yangzhou university, 2012.). In recent years, researches on the flavor of fermented soybean milk have been reported, and Zhaoyusang (research on fermented sour soybean milk beverage [ D ]. stannless: Jiangnan university, 2005) focuses on analyzing the relative contents of 2, 3-butanedione, 2, 3-pentanedione, pentanol and n-hexanal in the flavor substance determination of the fermented soybean milk beverage, and accounts for about 14% of the total flavor substances, so that the fermented soybean milk is provided with good flavor. In addition, when streptococcus thermophilus and lactobacillus bulgaricus jointly ferment cow milk and soybean milk, the 2, 3-pentanedione content produced by fermenting the soybean milk is obviously higher than that produced by cow milk. Therefore, screening the flavor of streptococcus thermophilus which has good fermentation performance in the soybean milk and can generate pleasant flavor is important for improving the quality of the sour soybean milk.
Disclosure of Invention
The invention discloses streptococcus thermophilus for high yield of 2, 3-pentanedione, which is used as a leaven to be applied to soybean milk fermentation so as to improve the flavor of fermented soybean milk and improve the quality of the fermented soybean milk, and has wide application prospect.
The invention provides Streptococcus thermophilus (Streptococcus thermophilus) CCFM1094 which is preserved in Guangdong province microorganism strain preservation center in 2019, 10 and 16 days, wherein the preservation number is GDMCC No. 60809, and the preservation address is No. 59 building 5 of Mirabilitum 100 of Guangzhou city.
The invention provides a preparation method of soybean milk with high content of 2, 3-pentanedione, which comprises the following specific steps: inoculating the preserved streptococcus thermophilus CCFM1094 into a culture medium for culture, and then carrying out subculture for 2-3 times until the strain concentration is 108～109cfu/mL, 1-6% volume ratio of the sample is inoculated in the soybean milk, the inoculated sample is placed in an incubator at 30-40 ℃ for fermentation for 6-10 h, and then the sample is placed in an environment at 0-10 ℃ for mature fermentation for 24-48 h.
In one embodiment of the invention, the streptococcus thermophilus CCFM1094 has a final concentration in soy milk of 106～1010cfu/mL。
In one embodiment of the present invention, the preparation method of the soybean milk comprises: weighing 50-200 g of dry soybeans, adding water for overnight soaking, boiling the soaked soybeans in boiling water, continuously boiling for 1-5 min, adding water according to the mass ratio of the water to the dry soybeans of 1: 3-8, grinding the soybeans in water at 50-70 ℃ for 5-10 min, continuously boiling for 3-10 min, cooling, filtering with 100-150 meshes of gauze, sterilizing at 90-120 ℃ for 5-15 min, and cooling to 15-35 ℃.
The invention provides a starter containing streptococcus thermophilus CCFM1094, and a preparation method of the starter comprises the following steps: inoculating Streptococcus thermophilus CCFM1094 into 10-30 mL of MRS liquid medium, activating for 2-3 generations at 25-35 ℃ until the Streptococcus thermophilus CCFM1094 reaches 106When the viable count is more than cfu/mL, centrifuging at 2000-6000 rpm for 15-25 min, removing supernatant, sequentially adding buffer solution and cryoprotectant in an aseptic environment until the cell concentration is not less than 106And (5) performing vacuum freeze drying treatment when cfu/mL is required to obtain the leavening agent.
In one embodiment of the present invention, the cell concentration is not less than 107And (5) performing vacuum freeze drying treatment when cfu/mL is required to obtain the leavening agent.
In one embodiment of the invention, the buffer solution is double distilled water and/or 0.1-2.0% (w/v) physiological saline, and the cryoprotectant is 5-20% (w/v) trehalose and/or skim milk powder.
In one embodiment of the invention, the buffer solution is double distilled water and/or normal saline, and the cryoprotectant is 10-15% (w/v) trehalose and/or 10-15% (w/v) skimmed milk powder.
The invention provides an application of lactococcus lactis subsp lactis CCFM1094 in preparation of sour soybean milk and fermented soybean milk beverages.
The invention provides application of the leavening agent in preparing cow milk, sour soybean milk and fermented soybean milk beverage.
In one embodiment of the invention, the addition amount of the leavening agent in the soybean milk is 2 to 8 percent of the mass of the soybean milk.
The invention provides an application of streptococcus thermophilus CCFM1094 in preparation of cow milk, sour soybean milk and fermented soybean milk beverages.
The invention has the beneficial effects that:
the streptococcus thermophilus CCFM1094 is a safe strain which is screened from yak yoghourt and can be used for food; the strain can well utilize cane sugar to ferment soybean milk, can produce acid quickly, can reach a fermentation end point quickly, can effectively improve the content of 2, 3-pentanedione in the fermented soybean milk by 116.73 mu g/kg, and can ensure that the soybean milk obtained by fermentation has stronger milk flavor and nut flavor; the contents of main flavor substances 2, 3-butanedione and acetoin in the sour soybean milk are also higher, and are 124.57 mu g/kg and 88.88 mu g/kg respectively; in addition, the content of benzyl alcohol and benzaldehyde related to the beany flavor of the soybean milk is low, and the content is respectively 2.20 mu g/kg and 10.27 mu g/kg, so that the strain is beneficial to the improvement of the beany flavor.
Biological material preservation
The Streptococcus thermophilus CCFM1094 is preserved in Guangdong province microbial strain preservation center in 2019, 10 and 16 days, and has the preservation number of GDMCC No. 60809, and the preservation address of No. 59 building 5 of Dazhou college No. 100 of Xieli Zhonglu, Guangzhou city.
Drawings
FIG. 1 shows the colony morphology of Streptococcus thermophilus CCFM 1094.
FIG. 2 is a photograph of gram-stained Streptococcus thermophilus CCFM1094 under a microscope at 1000 times.
FIG. 3 shows the growth of Streptococcus thermophilus CCFM1094 in soy milk.
FIG. 4 shows the change of pH of Streptococcus thermophilus CCFM1094 during the fermentation of soymilk.
FIG. 5 shows the sucrose content of Streptococcus thermophilus CCFM1094 after fermentation in soy milk.
Detailed Description
The present invention will be described in detail with reference to the accompanying drawings and examples.
M17 medium: 5g of tryptone, 5g of soybean peptone, 5g of beef extract, 2.5g of yeast extract, 0.5g of ascorbic acid, 19g of beta-sodium glycerophosphate, 0.25g of magnesium sulfate heptahydrate and 5g of lactose, metering to 1L, and adjusting the pH to about 7.1.
The control strain, Streptococcus thermophilus DQHXN7M2, was selected from Qinghai Xining yogurt in the same manner as Streptococcus thermophilus CCFM 1094.
Example 1: streptococcus thermophilus CCFM1094 strain separation and identification method
(1) Preparing appropriate sample dilution gradient and culturing
Taking out yak yogurt stored in Alba Sichuan area at-80 deg.C, and thawing on ice. After shaking and mixing evenly, 0.5mL of sample is added into 4.5mL of sterile physiological saline, and the dilution is completed by 10 times to 10 times-1After shaking and mixing evenly, 0.5mL of diluent is taken out from the diluent and added into 4.5mL of sterile physiological saline to finish the second 10-fold dilution to 10-2And the like until the dilution is 10-6And sucking 100 mu L of each gradient diluent, uniformly coating the diluent on an M17 solid culture medium plate, inverting, placing the plate at 37 ℃ for anaerobic culture for 36-48 h, and observing in time.
(2) Streaking separation and purification
And (3) taking out the plate with the grown bacterial colony, selecting a gradient plate with obvious single bacterial colony, selecting bacterial colonies with different bacterial colony morphologies, carrying out secondary streaking on an M17 solid medium plate, placing the plate at 37 ℃ for anaerobic culture for 36-48 h, and repeating the steps until all single bacterial colonies are purified.
(3) Gram stain and Catalase assay
Picking a single colony on a glass slide, performing smear, drying, fixing, primary dyeing, washing, mordanting, washing, decoloring, counterdyeing, washing, drying and microscopic examination, and recording a gram staining result; picking a single colony on a glass slide, adding a 3% hydrogen peroxide solution, observing whether bubbles are generated or not, and recording a catalase contact result (both gram staining and catalase contact experimental steps can refer to the master code of microbiology, Yankee Bo and the like, and higher education publishers, 2010); the bacteria which are positive in gram staining and negative in catalase experiment are screened out.
(4) Strain preservation
And (3) picking the single colony of each purified strain into 5mL of liquid M17 culture medium, placing the culture medium in anaerobic static culture at 37 ℃ for 20-24 h, sucking 1mL of bacterial liquid into a bacteria preservation tube, centrifuging at 6000rpm for 3min, pouring out the supernatant, adding 1mL of 37% sterile glycerol solution, resuspending, and placing the mixture in a place at-80 ℃ for preservation.
(5)16S rDNA sequence amplification
Sucking 1mL of bacterial liquid at 6000rpm, centrifuging for 3min, pouring out supernatant, washing twice, centrifuging and pouring out supernatant to obtain bacterial sludge, taking the bacterial sludge as a template to perform PCR amplification, wherein the process is as follows:
PCR amplification system 20. mu.L:
wherein the template amount is 1 μ L, the bidirectional primers are 1 μ L each, the Taq enzyme MasterMix is 10 μ L, ddH2O is 7. mu.L.
The primers used were:
27F：AGA GTT TGA TCC TGG CCT CA，1492R：GGT TAC CTT GTT ACG ACT T。
PCR amplification conditions:
pre-denaturation: 3min at 95 ℃;
first-step denaturation: 1min at 94 ℃;
and a second step of annealing: 37s at 60 ℃;
and a third step of extension: 2min at 72 ℃;
cycle number: cycling the first to third steps for 37 times;
the fourth step is finally extended: 5min at 72 ℃;
the fifth step is that: 10min at 12 ℃.
(6) Agarose gel electrophoresis
Weighing 80mL of agarose, adding the agarose into a conical flask, adding 80mL of 1 XTAE, heating intermittently by microwave for 4min until the liquid is clear and transparent, slightly cooling, adding 4 muL of nucleic acid dye, shaking up without bubbles, pouring the mixture into a gel plate groove, cooling for 40min, solidifying, placing the mixture into an electrophoresis groove, discharging bubbles, sequentially adding PCR amplification products, adding 2 muL of PCR amplification products into each hole, running the gel for 120V 15min, taking out the mixture after the completion, placing the mixture into a gel electrophoresis imager for photographing and storing, recording the serial number of samples with successful PCR, and placing the successful PCR products into a refrigerator at-20 ℃ for storage.
(7) Sequencing and identification
And (3) sending the sample with the successful PCR to an England Weiji (Shanghai) trade company Limited for detection, performing BLAST retrieval in a sequence database (http:// www.ncbi.nlm.nih.gov/BLAST) of the National Center for Biotechnology Information (NCBI) according to the fed-back sequence result, and selecting the strain information with the highest matching degree for result recording. The strain provided by the invention is streptococcus thermophilus (Lactococcus lactis subsp.
(8) Strain preservation
And (4) preserving the strain in the step (7) in Guangdong province microbial strain preservation center in 2019, 10 and 16 days.
Example 2: fermentation characteristic of streptococcus thermophilus CCFM1094 in soybean milk
1. Growth characteristics of Streptococcus thermophilus CCFM1094 in soymilk
Inoculating the streptococcus thermophilus CCFM1094 preserved at the temperature of-80 ℃ in an M17 culture medium, culturing for 24 hours at the temperature of 37 ℃, and subculturing for 2-3 times to 108～109cfu/mL. Taking out the bacteria liquid activated in M17, inoculating the bacteria liquid into the soybean milk according to the volume ratio of 2-4 percent, and leading the number of the viable bacteria in the system to reach 107cfu/g. The inoculated sample is put into an incubator at 37 ℃ for fermentation, samples are taken every 3h, and the change of the viable count in the fermentation process is detected, and the result is shown in figure 2. As can be seen from FIG. 2, the increase of viable count of the strain CCFM1094 reaches 2.36 orders of magnitude after 9 hours of fermentation, while the increase of viable count of the Streptococcus thermophilus DQHXN7M2 reaches 1.67 orders of magnitude after 15 hours of fermentation, so that the growth rate of the strain CCFM1094 in soybean milk is high.
2. Acid production characteristic of streptococcus thermophilus CCFM1094 in soybean milk
Inoculating the streptococcus thermophilus CCFM1094 preserved at the temperature of-80 ℃ in an M17 culture medium, culturing for 24 hours at the temperature of 37 ℃, and subculturing for 2-3 times to 108～109cfu/mL. Taking out the bacteria liquid activated in M17, inoculating the bacteria liquid into the soybean milk according to the volume ratio of 2-4 percent, and leading the number of the viable bacteria in the system to reach 107cfu/g. And (3) fermenting the inoculated sample in an incubator at 37 ℃, sampling every 3h, and detecting the change of pH in the fermentation process, wherein the experimental result is shown in figure 3. As shown in FIG. 3, after 9 hours of fermentation, the pH of the strain CCFM1094 is reduced to 4.59, and the end of fermentation is reached (when the soybean milk is fermented to pH 4.5-4.7, the end of fermentation is reachedPoint), while the pH of the streptococcus thermophilus DQHXN7M2 is only reduced to 5.82 after the fermentation for the same time, and the pH can be reduced to 4.65 after the fermentation for 15h, so the strain CCFM1094 has a higher acid production rate in the soybean milk and is suitable for fermentation in the soybean milk.
Example 3: application of streptococcus thermophilus CCFM1094 fermented soybean milk
(1) Fermentation of soymilk
The preparation method of the soybean milk comprises the following steps: weighing 100g of dry soybean, adding 1L of deionized water, soaking overnight, boiling the soaked soybean in boiling water, decocting for 2min, adding 600mL of deionized water, grinding at 60 deg.C for 6min, decocting for 5min, cooling, filtering with 120 mesh gauze, sterilizing at 105 deg.C for 10min, and cooling to room temperature.
Inoculating the streptococcus thermophilus CCFM1094 preserved at the temperature of-80 ℃ in an M17 culture medium, culturing for 24 hours at the temperature of 37 ℃, and subculturing for 2-3 times to 108～109cfu/mL. Taking out the bacteria liquid activated in M17, inoculating the bacteria liquid into sterilized fresh soybean milk according to the volume ratio of 2-4 percent, and leading the viable count in the system to reach 107cfu/g, placing the inoculated sample into an incubator at 37 ℃ for fermentation.
(2) High Performance Liquid Chromatography (HPLC) for measuring sucrose content of fermented soybean milk
And (3) soybean milk sample treatment: weighing 2g of soybean milk sample, adding 1.5mL of ultrapure water for dilution, incubating for 10min at 60 ℃, sequentially adding 0.25mL of 0.5mol/L potassium ferrocyanide solution, 0.25mL of 0.5mol/L zinc acetate solution and 1.0mL of acetonitrile solution, slowly mixing, standing for 4h at room temperature, centrifuging for 8min at 9000g/min, taking supernatant, filtering by using a 0.22 mu m water system filter membrane, and performing ultrasonic treatment on the filtered supernatant for 5min at 40W to remove dissolved bubbles, wherein two samples are parallel. The treated soy milk samples were tested by HPLC method.
Liquid chromatography conditions: a Waters Sugar-Pak I column (370X 6.5mm) was selected, the column temperature was 85 ℃ and the mobile phase ultrapure water flow rate was 0.4mL/min, and an evaporative light scattering detector was selected, and the injection volume was 10. mu.L. And (5) performing substance qualification according to the peak output time of the standard substance, and quantifying by using a peak area external standard method.
(3) Gas chromatography-mass spectrometry (GC-MS) combined method for measuring content of volatile substances after soybean milk fermentation
And (3) soybean milk sample treatment: with reference to the method of Li et al (Li C, Li W, Chen X, et al. microbiological, physical and microbiological properties of compensated soymilk products with ex-plopylytic lactic acid bacteria strains [ J ]. LWT-Food Science and Technology, 2014, 57(2):477-485.) and modified by preliminary experiments, 5g of fermented soy milk samples were weighed into 20mL extraction vials, recorded for exact mass (two bits after decimal point), and 1.0g of sodium chloride and 2. mu.L of 0.1mg/mL of 2-methyl-3-heptanone (internal standard) were added in sequence, with two samples each in parallel. The treated samples were assayed by GC-MS.
Gas chromatography conditions and temperature program: an Rtx-WAX capillary (37m × 0.25mm, 0.25mm) is selected, the injection inlet temperature is 225 ℃, the split ratio is 10, and the flow rate of the carrier gas (helium) is 1 mL/min. The temperature-raising program sets the initial temperature at 37 ℃ and keeps the temperature for 3min, and raises the temperature to 225 ℃ at 15 ℃/min and keeps the temperature for 5 min.
Mass spectrum conditions: the ionization mode EI has the emission energy of 70eV, the emission current of 200 muA, the detector voltage of 1.4kV, the ion source temperature of 240 ℃, the interface temperature of 237 ℃, the quadrupole rod temperature of 150 ℃ and the mass scanning range of m/z of 37-500. And (3) performing substance qualitative determination on the spectrogram obtained by GC-MS by searching in a NIST 2001 standard spectrum library and comparing standard substances, and quantifying by using a peak area normalization method.
(4) Sugar content after fermentation
The sucrose content in the fermented soy milk is shown in figure 4. As can be seen from FIG. 4, the sucrose content in the soybean milk before fermentation was 2.70g/L, the sucrose content in Streptococcus thermophilus CCFM1094 after reaching the end of fermentation (9h) was lower and was 0.93g/L, the sucrose utilization was about 1.74 g/L, and the sucrose utilization was 64%; while the sucrose content of the streptococcus thermophilus after the fermentation is finished (15h) is 1.91g/L after DQHXN7M2 fermentation, and the sucrose utilization amount is about 0.79 g/L. Therefore, the streptococcus thermophilus CCFM1094 has strong sucrose utilization capacity.
(5) Content of volatile matter after fermentation
The content of volatile substances in the fermented soybean milk is shown in table 1. As can be seen from Table 1, after 9 hours of fermentation, the content of 2, 3-pentanedione in the fermented soybean milk is 116.73 μ g/kg, which is significantly higher than the amount of DQHXN7M2 produced by Streptococcus thermophilus at the end of the fermentation, and the content thereof only reaches about 89 μ g/kg, so that the Streptococcus thermophilus CCFM1094 has good ability to produce milk flavor. In addition, the contents of 2, 3-butanedione and acetoin produced by fermentation of streptococcus thermophilus CCFM1094 are also high and are 124.57 mu g/kg and 88.88 mu g/kg respectively, and the contents of benzyl alcohol and benzaldehyde related to beany flavor of the soybean milk are only 2.2 mu g/kg and 10.27 mu g/kg, so that the streptococcus thermophilus CCFM1094 can effectively reduce the beany flavor substances in the soybean milk in the fermentation of the soybean milk and produce good flavor substances.
TABLE 1 content of volatile substances in soymilk
Figure BDA0002382343860000071
Although the present invention has been described with reference to the preferred embodiments, it should be understood that various changes and modifications can be made therein by those skilled in the art without departing from the spirit and scope of the invention as defined in the appended claims.

Claims (10)

1. A strain of Streptococcus thermophilus (Streptococcus thermophilus) has been deposited in Guangdong province culture Collection (CGMCC) at 10 and 16 months 2019, and the deposit number is GDMCC No. 60809.
2. A starter culture comprising the Streptococcus thermophilus of claim 1.
3. The method for preparing the leaven according to claim 2, wherein the method comprises: centrifuging a bacterium solution obtained after activation of streptococcus thermophilus according to claim 1, taking a precipitate, adding a buffer solution and a freezing protective agent into the precipitate to obtain a resuspension solution, and finally performing vacuum freeze drying on the resuspension solution to obtain a leavening agent.
4. The method of claim 3, wherein the resuspension is performed in a single operationThe cell concentration of Streptococcus thermophilus in the solution is not less than 106cfu/mL。
5. The method of claim 3, wherein the buffer is double distilled water and/or normal saline and the cryoprotectant is trehalose and/or skim milk powder.
6. A method for preparing soybean milk containing 2, 3-pentanedione, characterized in that the Streptococcus thermophilus of claim 1 or the starter of claim 2 is inoculated into soybean milk and fermented to obtain the soybean milk.
7. The method according to claim 6, wherein the Streptococcus thermophilus of claim 1 is added to the soybean milk in an amount of not less than 106cfu/g。
8. The method according to claim 6, wherein the addition amount of the leavening agent in the soybean milk is 1-10% by mass of the soybean milk.
9. The method according to claim 6, wherein the soybean milk is fermented for 5-10 hours.
10. Use of streptococcus thermophilus according to claim 1 or starter according to claim 2 for the preparation of a fermented soy milk, fermented soy milk drink.
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