Bacillus subtilis BS-TS1 and its application in preparing distiller's yeast and wine products

Abstract

The present invention provides a Bacillus subtilis BS-TS1 and its application in preparing distiller's yeast and wine products, belonging to the technical field of brewing microorganisms. The deposit number of the Bacillus subtilis BS-TS1 provided by the present invention is CGMCC No.32285. The Bacillus subtilis BS-TS1 provided by the present invention has the advantages of high resistance to Penicillium and high production of aroma substances. The Daqu prepared using Bacillus subtilis BS-TS1 has significant anti-Penicillium properties and is not easily contaminated during the production process of Daqu. The lees juice prepared from the Daqu obtained by using Bacillus subtilis BS-TS1 is rich in volatile aroma substances, among which the content of acetoin reaches 150.944 mg / L, the content of pyrazine reaches 301.353 mg / L, and the content of 2,3-butanediol reaches 21.319 mg / L; in addition, other aroma components such as ethyl butyrate and phenylethanol are also detected.

Description

Technical Field

[0001] The invention belongs to the technical field of wine-making microorganisms, and particularly relates to a Bacillus subtilis BS-TS1 and an application thereof in preparing wine yeast and wine products. Background Art

[0002] There are five main types of koji (dice yeast): Daqu (big koji), Xiaoqu (small koji), Wheat Qu (wheat koji), Red Qu (red koji), and Wheat koji. Daqu (big koji) uses wheat as its primary raw material and utilizes naturally occurring microorganisms and specialized processes for the fermentation of baijiu (white liquor). The microbial community within Daqu plays a crucial role in the fermentation process.

[0003] Bacillus subtilis is a long, rod-shaped, spore-forming Gram-positive bacterium. When faced with adverse conditions such as nutrient deprivation and drought, it forms spores. In recent years, research on the microbial flora in Daqu has deepened, clarifying the complex processes involved in the formation and flavor development of Daqu, and revealing the key role played by Bacillus subtilis. Under conditions of high temperature, high salt, and low oxygen, it can produce a variety of biologically active metabolites, such as antibiotics, enzymes, and antibacterial peptides. These metabolites have shown great potential in inhibiting the growth of pathogenic microorganisms, promoting plant growth, and enhancing plant disease resistance.

[0004] The aroma compounds in baijiu can be primarily categorized into esters, alcohols, and aldehydes. The main aroma compounds produced by Bacillus subtilis include volatile fatty acids, such as acetic acid, propionic acid, and butyric acid, which typically exhibit a sour, fermented aroma. Furthermore, alcohols such as ethanol and isoamyl alcohol exhibit fruity and wine-like aromas; esters such as ethyl acetate and ethyl butyrate often have a fruity aroma; ketones such as ethyl ketone have a sweet aroma; and aldehydes such as acetaldehyde typically have a refreshing fragrance. The production of these aroma compounds is closely related to the metabolic activity of Bacillus subtilis and is widely used in food fermentation, spice production, and biotechnology.

[0005] During production and application, Bacillus strains may be affected by various factors, such as temperature, pH, and humidity, which may directly or indirectly weaken the stability of the strains, leading to a decrease in their antibacterial properties. Therefore, how to ensure the stability and activity of the strains is a key issue in current research. Summary of the Invention

[0006] In view of this, the object of the present invention is to provide a Bacillus subtilis that is highly resistant to Penicillium and produces a high amount of aroma substances.

[0007] In order to achieve the above-mentioned object of the invention, the present invention provides the following technical solutions:

[0008] The invention provides a Bacillus subtilis BS-TS1. The Bacillus subtilis BS-TS1 is classified as Bacillus subtilis and is deposited in the General Microbiology Center of the China Culture Collection Administration of Microorganisms with a deposit number of CGMCC No. 32285.

[0009] The present invention also provides a fermentation method of the Bacillus subtilis BS-TS1, comprising inoculating the Bacillus subtilis BS-TS1 into a fermentation substrate and fermenting at 30-40° C. for 48-96 hours; the fermentation speed is 120-200 r / min, and the pH of the fermentation substrate is 6.5-8.

[0010] The present invention also provides the use of the Bacillus subtilis BS-TS1 in preparing distiller's yeast.

[0011] Preferably, the koji includes Daqu.

[0012] The present invention also provides a Daqu that is resistant to Penicillium and rich in aroma substances. The bacteria used for fermenting the Daqu include the above-mentioned Bacillus subtilis BS-TS1.

[0013] The present invention also provides the use of the above-mentioned Daqu in preparing wine products.

[0014] Preferably, the wine product includes white wine.

[0015] Preferably, the liquor comprises sorghum liquor.

[0016] The present invention also provides a white wine brewed from the above-mentioned Daqu.

[0017] Beneficial effects of the present invention:

[0018] The Bacillus subtilis BS-TS1 provided by the present invention has the advantages of high resistance to Penicillium and high production of aromatic substances. The Daqu prepared using the Bacillus subtilis BS-TS1 provided by the present invention has significant resistance to Penicillium and is not easily contaminated during the production process of Daqu. The lees juice prepared from the Daqu prepared using the Bacillus subtilis BS-TS1 of the present invention is rich in volatile aromatic substances, among which the content of acetoin reaches 150.944 mg / L, the content of pyrazine reaches 301.353 mg / L, and the content of 2,3-butanediol reaches 21.319 mg / L; in addition, other aromatic components such as ethyl butyrate, propyl butyrate, and phenylethyl alcohol are also detected.

[0019] The Daqu prepared by using the Bacillus subtilis BS-TS1 of the present invention not only has the advantages of high resistance to Penicillium and high yield of aroma substances, but also has the advantage of stable performance. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 The morphological identification results of Bacillus BS-TS1 are shown in Figure 1. The left picture shows the colony morphology, and the right picture shows the Gram-stained bacterial morphology.

[0021] Figure 2 The results of plate confrontation of BS-TS1 strain, from left to right, are the results of culturing for 24 hours, 48 ​​hours, and 72 hours respectively;

[0022] Figure 3 The agar column method inhibition results of Bacillus BS-TS1, where the left picture is Penicillium + BS-TS1, and the right picture is Penicillium;

[0023] Figure 4 The effect of different fermentation temperatures on the antibacterial activity of the supernatant of strain BS-TS1;

[0024] Figure 5 The effect of different initial pH values ​​on the antibacterial activity of the supernatant of strain BS-TS1;

[0025] Figure 6 The effect of different shaking speeds on the antibacterial effect of the supernatant of strain BS-TS1;

[0026] Figure 7 The effect of different fermentation times on the antibacterial activity of the supernatant of strain BS-TS1;

[0027] Figure 8 This is the total ion chromatogram of the fermentation broth of Bacillus subtilis BS-TS1 strain;

[0028] Figure 9 This is a diagram of the production of Daqu after inoculation with Penicillium and BS-TS1, where from left to right are inoculation with only Saccharomyces cerevisiae, inoculation with Saccharomyces cerevisiae + BS-TS1, inoculation with Saccharomyces cerevisiae + Penicillium + BS-TS1, and inoculation with Saccharomyces cerevisiae + Penicillium;

[0029] Figure 10 This is the total ion chromatogram result of GC-MS of Saccharomyces cerevisiae fermentation broth;

[0030] Figure 11 This is the GC-MS total ion chromatogram result of Saccharomyces cerevisiae + BS-TS1 Daqu fermentation liquid;

[0031] Figure 12 This is the total ion chromatogram result of GC-MS of commercial Daqu fermentation broth.

[0032] Preservation Instructions

[0033] The Bacillus subtilis BS-TS1 of the present invention is deposited in the General Microbiology Center of the China Culture Collection Administration Committee of Microorganisms, and is classified and named Bacillus subtilis. The deposit address is No. 3, Yard 1, Beichen West Road, Chaoyang District, Beijing, Institute of Microbiology, Chinese Academy of Sciences, the deposit number is CGMCC No. 32285, and the deposit date is October 21, 2024. DETAILED DESCRIPTION

[0034] The invention provides a Bacillus subtilis BS-TS1. The Bacillus subtilis BS-TS1 is classified as Bacillus subtilis and is deposited in the General Microbiology Center of the China Culture Collection Administration of Microorganisms with a deposit number of CGMCC No. 32285.

[0035] The Bacillus subtilis BS-TS1 provided by the present invention was screened from Daqu grown in the applicant's laboratory. When grown on LB plates, the Bacillus subtilis BS-TS1 forms pale yellow, translucent, round colonies with a smooth and sticky surface, protruding shapes, and neat edges. These morphological characteristics are typical of Bacillus. Furthermore, the Bacillus subtilis BS-TS1 provided by the present invention is a Gram-positive bacterium with high resistance to Penicillium and high production of aroma substances, including acetoin, 2,3-butanediol, and pyrazine.

[0036] The present invention also provides a fermentation method of the Bacillus subtilis BS-TS1, comprising inoculating the Bacillus subtilis BS-TS1 into a fermentation substrate and fermenting at 30-40° C. for 48-96 hours; the fermentation speed is 120-200 r / min, and the pH of the fermentation substrate is 6.5-8.

[0037] In the present invention, the fermentation substrate preferably includes a culture medium or a raw material for preparing koji, and the culture medium preferably includes LB liquid culture medium and a modified LB liquid culture medium, wherein the modified LB liquid culture medium is composed of 10.0 g of peptone, 5.0 g of yeast extract, 10.0 g of NaCl, 20 g of corn steep liquor powder, 80 g of glucose and 1000 mL of distilled water.

[0038] In the present invention, the fermentation temperature is preferably 33-38°C; the fermentation time is preferably 50-80°C, more preferably 60-75°C; the fermentation speed is preferably 130-180 r / min; and the pH of the fermentation substrate is preferably 7.

[0039] The present invention also provides the use of the Bacillus subtilis BS-TS1 in preparing distiller's yeast. In the use of the present invention, the distiller's yeast preferably comprises Daqu.

[0040] The present invention also provides a Daqu (Chinese koji) that is resistant to Penicillium and rich in aroma substances. The bacteria used to ferment the Daqu include the aforementioned Bacillus subtilis BS-TS1. The Daqu fermented with the Bacillus subtilis BS-TS1 of the present invention has the advantages of being highly resistant to Penicillium and other bacteria, is not easily contaminated during the fermentation process, and exhibits stable fermentation characteristics.

[0041] The present invention also provides the use of the above-mentioned Daqu in preparing a wine product. In the use of the present invention, the wine product preferably includes white wine, and the white wine preferably includes sorghum white wine.

[0042] The present invention also provides a liquor brewed from the above-mentioned Daqu. The liquor brewed from the Daqu of the present invention has no unpleasant flavor (musty or fungal flavor) and has a strong characteristic aroma of acetoin, 2,3-butanediol, and pyrazine.

[0043] The technical solutions provided by the present invention are described in detail below with reference to the embodiments, but they should not be construed as limiting the scope of protection of the present invention.

[0044] In the following examples, unless otherwise specified, all methods are conventional.

[0045] Unless otherwise specified, the materials and reagents used in the following examples can be obtained from commercial sources.

[0046] Example 1

[0047] 1.1 Isolation and purification of Bacillus subtilis

[0048] First, crush the Daqu stored in the laboratory and weigh 1g. Add it to 9mL of sterile 0.9% saline, mix thoroughly, and heat it in an 80℃ water bath for 20min to kill non-spore-forming microorganisms. Then, add this stock solution to 90mL of LB liquid culture medium and perform enrichment culture at 37℃ for 24h. After the enrichment culture is completed, take 1mL of the bacterial solution and add it to 9mL of sterile saline. Perform a 10-fold gradient dilution until it reaches 10. -6 g / mL dilution concentration. Take 10 - 4 g / mL, 10 -5 g / mL and 10 -6 Inoculate 100 μL of each sample at a 0.5 g / mL dilution onto a LB solid medium plate, spread evenly, and incubate in a 37°C incubator for 18–24 hours. Based on the morphological characteristics of the Bacillus, isolate individual colonies and purify them using the streak method until a single, pure strain is obtained. Observe the isolated bacteria morphologically and perform Gram staining. Finally, transfer microscopically positive Bacillus to LB solid medium and store on a slant for future use.

[0049] 1.2 Screening of Bacillus subtilis that inhibits Penicillium

[0050] The plate confrontation method was used to preliminarily screen Bacillus that inhibited the growth of Penicillium, and then the agar column method was used as a re-screening method, and the inhibition rate was calculated. The steps of the plate confrontation method are as follows: First, the Penicillium picked up with an inoculation loop was inoculated in the center of the PDA culture medium, and then the Bacillus was inoculated around the Penicillium. The growth of the two strains was observed every 24 hours to screen out Bacillus subtilis that has an inhibitory effect on the growth of Penicillium. The steps of the agar column method are: add the fermentation supernatant of Bacillus subtilis to the PDA culture medium at a ratio of 1:10, use a punch to take out the Penicillium cake and place it in the center of the PDA culture medium, and culture it at a constant temperature of 28°C. Using the cross method, measure the diameter of the bacteria every 12 hours until the bacteria in the blank control culture dish are full. The calculation formula for the inhibition rate of Bacillus subtilis is as follows:

[0051]

[0052] The results showed that Bacillus subtilis BS-TS1 had the best antibacterial effect. The morphological identification results of Bacillus subtilis BS-TS1 are shown in Figure 1 When grown on LB plates, the strain forms pale yellow, translucent, round colonies with a smooth and sticky surface, protruding colonies, and neat edges. These morphological characteristics are consistent with the typical characteristics of Bacillus, and the strain is a Gram-positive bacterium. The plate confrontation results of Bacillus subtilis BS-TS1 are shown in Figure 2 The results of the agar column method for the inhibition of Bacillus subtilis BS-TS1 are shown in Figure 3 .

[0053] Example 2

[0054] Optimization of Fermentation Conditions of Bacillus subtilis BS-TS1

[0055] 2.1 Temperature

[0056] The Bacillus subtilis BS-TS1 obtained in Example 1 was inoculated into a conical flask containing 50 mL of LB liquid culture medium at an inoculum volume of 1%. The conical flask was placed on a shaker at 140 r / min and cultured for 48 hours at five temperature gradients of 25°C, 30°C, 37°C, 40°C and 45°C. After the culture was completed, the fermentation broth of the strain was centrifuged at 10,000 r / min for 20 minutes, the supernatant was taken out and added to PDA culture medium. The antibacterial rate was calculated according to the agar column method (same as in Example 1), and a bar graph was drawn. Each experimental condition was repeated three times. The results are shown in FIG. Figure 4At 25°C, 30°C, 37°C, 40°C, and 45°C, the average inhibition rates of Bacillus subtilis BS-TS1 were 37.98%, 66.21%, 81.84%, 56.11%, and 49.23%, respectively. Among them, the highest inhibition rate against Penicillium was achieved at 37°C.

[0057] 2.2pH

[0058] The Bacillus subtilis BS-TS1 obtained in Example 1 was inoculated into a conical flask containing 50 mL of LB liquid culture medium at an inoculum size of 1% by volume, and the pH values ​​of these culture media were set to 5, 6, 7, 8 and 9. The conical flask was placed on a shaker at 140 r / min and cultured for 48 hours at 37°C. After the culture was completed, the fermentation broth of the strain was centrifuged at 10,000 r / min for 20 minutes, the supernatant was taken out and added to the PDA culture medium. The antibacterial rate was calculated according to the agar column method (same as in Example 1), and a bar graph was drawn to determine the optimal culture pH value. Each experimental condition was repeated three times. The results are shown in FIG. Figure 5 The average inhibition rates of the fermentation supernatant of strain BS-TS1 were 37.98%, 49.23%, 85.94%, 64.00% and 56.11% at initial pH values ​​of 5, 6, 7, 8 and 9, respectively. Among them, the highest inhibition rate against Penicillium was achieved at an initial pH value of 7.

[0059] 2.3 Shaker speed

[0060] The Bacillus subtilis BS-TS1 obtained in Example 1 was inoculated with 1% volume of inoculum into a conical flask containing 50 mL of LB liquid culture medium (pH 7), and different shaking speed conditions were set, namely 40 r / min, 80 r / min, 120 r / min, 160 r / min and 200 r / min, and cultured at 37°C for 48 hours. After the culture was completed, the strain fermentation liquid was centrifuged at 10,000 r / min for 20 minutes, the supernatant was taken out and added to the PDA culture medium. The antibacterial rate was calculated according to the agar column method (same as in Example 1), and a bar chart was drawn to determine the optimal culture shaking speed. Each experimental condition was repeated three times. The results are shown in Figure 6 At 40 r / min, 80 r / min, 120 r / min, 160 r / min, and 200 r / min, the average inhibition rates of the fermentation supernatant of strain BS-TS1 were 49.23%, 51.00%, 69.75%, 79.75%, and 48.52%, respectively. Among them, the highest inhibition rate against Penicillium was achieved at a shaking speed of 160 r / min, so 160 r / min was selected as the optimal shaking speed.

[0061] 2.4 Time

[0062] The Bacillus subtilis BS-TS1 obtained in Example 1 was inoculated into a conical flask containing 50 mL of LB liquid culture medium (pH 7) at an inoculum size of 1% by volume. Under 37°C conditions, the conical flask was cultured in a shaking incubator at 160 r / min for 24 hours, 48 ​​hours, 72 hours, 96 hours and 120 hours respectively. After the culture was completed, the fermentation broth of the strain was centrifuged at 10,000 r / min for 20 minutes, the supernatant was taken out and added to the PDA culture medium. The antibacterial rate was calculated according to the agar column method (same as in Example 1), and a bar graph was drawn to determine the optimal culture time. Each experimental condition was repeated three times. The results are shown in FIG. Figure 7 After culturing for 24, 48, 72, 96, and 120 hours, the inhibition rates of strain BS-TS1 were 64.00%, 79.75%, 85.89%, 72.64%, and 68.34%, respectively. Among them, the highest inhibition rate against Penicillium was achieved in the fermentation broth of strain BS-TS1 after culturing for 72 hours.

[0063] Based on the above test data, it can be determined that the strain BS-TS1 has the best antibacterial properties under the following conditions: the culture temperature is set at 37°C, the initial pH value of the culture medium is adjusted to 7.0, the shaker speed is controlled at 160 r / min, and the culture is continued for 72 hours.

[0064] Example 3

[0065] 3.1 Experimental Materials

[0066] Fermentation medium: modified LB liquid medium: peptone 10.0 g, yeast extract 5.0 g, NaCl 10.0 g, corn steep liquor powder 20 g, glucose 80 g, distilled water 1000 mL, pH 7.0. Sterilize by high-pressure steam at 121°C for 20 min.

[0067] 3.2 Experimental methods

[0068] Bacillus subtilis BS-TS1 was fermented under the optimal antibacterial conditions obtained in Example 2. Finally, aroma compounds in the fermentation broth were determined using GC-MS headspace solid phase microextraction to determine the aroma characteristics of the late-stage Daqu. The specific fermentation process is as follows:

[0069] First, the Bacillus subtilis BS-TS1 screened out in Example 1 was inoculated into the fermentation medium at an inoculum size of 10%, and fermented for 72 hours at a set temperature of 37° C. and a rotation speed of 160 r / min. Finally, the types and percentages of aroma substances were determined.

[0070] 3.3 Detection method

[0071] Take 8 mL of fermentation broth and perform GC-MS headspace solid phase microextraction to determine the type and percentage of aroma substances. The determination method is:

[0072] Add 1.5 g of NaCl to a 20 mL screw-cap bottle, transfer 8 mL of fermentation broth to the bottle, and sonicate for 15 minutes. Add 10 μL of internal standard and sonicate again for 10 minutes before performing GC-MS headspace solid-phase microextraction.

[0073] The detection method is:

[0074] GC conditions: the chromatographic column was an RTX-WAX capillary column (30 m × 0.25 μm × 0.25 mm); the carrier gas was high-purity helium; the injection was splitless, and the injection port temperature was 250 °C; the column temperature was programmed: the programmed temperature was 40 °C for 3 min, increased to 130 °C at 2 °C / min, and increased to 220 °C at 10 °C / min, and maintained for 4 min.

[0075] MS conditions: chromatographic-mass spectrometric interface temperature 250°C, ion source temperature 230°C; ionization mode: electron impact source (EI), bombardment energy 70 eV.

[0076] 3.4 Test results

[0077] The GC-MS total ion current results of the fermentation broth of Bacillus subtilis BS-TS1 strain are shown in Figure 8 The results of the determination of the fermentation products of Bacillus subtilis BS-TS1 are shown in Table 1:

[0078] Table 1 Determination results of fermentation products of Bacillus subtilis BS-TS1

[0079]

[0080]

[0081] As can be seen from Table 1, pyrazine accounts for 64.23% of the aroma components, acetoin accounts for 9.83%, and 2,3-butanediol accounts for 17.81%. This indicates that the Bacillus subtilis BS-TS1 strain of the present invention has the characteristics of efficient fermentation production of pyrazine, acetoin, and 2,3-butanediol, which is of great significance for subsequent research on the flavor of liquor.

[0082] Example 4

[0083] 4.1 Experimental Materials

[0084] 15kg sorghum; Saccharomyces cerevisiae; Bacillus subtilis BS-TS1; Penicillium.

[0085] 4.2 Experimental methods

[0086] 4.2.1 Production of Daqu

[0087] Select high-quality wheat and barley as raw materials. Crush the selected grains and grind them into coarse powder for subsequent saccharification and fermentation. Mix the coarse powder with water and cook it to gelatinize the starch for the subsequent saccharification process. Cool the cooked mixture to 37°C and then inoculate Aspergillus. This step is to help convert starch into sugar. Let Aspergillus work and convert starch into fermentable sugars. Divide the saccharified substances into two groups and put them into fermentation containers: Group a adds 20g of brewer's yeast; Group b adds 20g of brewer's yeast and 20g of Bacillus subtilis BS-TS1; Group c adds 20g of brewer's yeast, 20g of Bacillus subtilis BS-TS1 and 20g of Penicillium and stir evenly; Group d adds 20g of brewer's yeast and 20g of Penicillium and stir evenly. Natural fermentation is carried out under the same conditions for 14 days. After fermentation is completed, the Daqu is dried or dried to reduce its moisture. After reaching a state suitable for long-term storage, the cross-section effect of the Daqu is immediately observed, such as Figure 9 shown.

[0088] 4.2.2 Fermentation test

[0089] First, 15kg of plump sorghum was steamed and divided into three groups. Each group was air-dried to 35°C. 500g of koji (dissolved yeast) from Group A, 500g of koji from Group B, and commercial koji were added to each. After thorough mixing, the grains were collected and stacked in ceramic jars for three days of aerobic fermentation. During this period, the microorganisms in the lees thrived, producing various aromatic substances. After three days, when a distinct wine aroma and sweetness developed, 2kg of white sugar was added to each group. The jars were then wrapped with plastic wrap and covered with ceramic lids for 30 days of fermentation.

[0090] 4.3 Detection methods

[0091] 8 mL of each of the three fermented lees juices was taken for GC-MS headspace solid phase microextraction to determine the types and percentages of aroma substances, using the same determination method as in Example 3.

[0092] 4.4 The test results are shown in Tables 2 to 4, and Figures 10 to 12 .

[0093] Table 2a Determination results of Daqu fermentation products

[0094] name Content (mg / L) Ethyl Acetate 5.56(±0.46) 1-Propanol,2-methyl-(isobutanol) 5.17(±0.72) 1-Butanol,3-methyl-,acetate(Isoamyl acetate) 10.45(±1.68) 1-Butanol,3-methyl-(isoamyl alcohol) 133.29(±4.66) Hexanoic acid, ethylester (ethyl hexanoate) 32.96(±1.97) Octanoic acid, ethylester (octanoic acid ethyl ester) 57.24(±3.41) Decanoic acid, ethylester (decanoic acid ethyl ester) 13.39(±1.05) Aceticacid,2-phenylethylester(Phenylethyl acetate) 2.55(±0.31) Dodecanoic acid, ethylester (ethyl laurate) 1.08(±0.12) PhenylethylAlcohol 29.71(±1.87)

[0095] Table 3b Determination results of Daqu fermentation products

[0096] name Content (mg / L) 2,3-Butanedione 9.172(±2.34) Butanoic acid, 2-methyl-, ethylester (ethyl butanoate) 2.745(±0.65) 1-Propanol,2-methyl-(isobutanol) 5.717(±1.71) Acetoin 150.944(±8.69) Pyrazine,tetramethyl-(pyrazine) 301.353(±12.74) 2,3-Butanediol,[R-(R*,R*)]-(2,3-Butanediol) 21.319(±2.41) Propanoic acid, 2-methyl-(ethyl isobutyrate) 17.671(±2.26) Butanoic acid, 2-methyl-(propyl butanoate) 31.257(±4.36) PhenylethylAlcohol 13.734(±2.08)

[0097] Table 4 Determination results of commercial Daqu fermentation products

[0098]

[0099]

[0100] It can be seen from the results in Tables 2 to 4 that the contents of aroma substances such as pyrazine, 2,3-butanediol, acetoin, propyl butyrate, 2,3-butanedione and butyl acetate in the lees juice obtained by fermentation of the Daqu prepared by the strain BS-TS1 of the present invention are higher than those after commercial Daqu and fermentation without adding the strain BS-TS1. Through the subsequent distillation processing, the distilled liquor has a great sauce-flavored aroma, thereby enhancing the market competitiveness of the fragrant liquor prepared by the strain of the present invention.

[0101] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principles of the present invention. These improvements and modifications should also be regarded as within the scope of protection of the present invention.

Claims

1. An application of Bacillus subtilis BS-TS1 in preparing distiller's yeast, characterized in that: The Bacillus subtilis BS-TS1 is classified and named Bacillus subtilis, and is deposited in the General Microbiology Center of the China Culture Collection Administration, with a deposit number of CGMCC No. 32285. The koji is resistant to Penicillium and rich in aroma substances. The aroma substances include pyrazine, 2,3-butanediol, acetoin, propyl butyrate, 2,3-butanedione and butyl acetate.

2. The use according to claim 1, characterized in that The koji includes daqu.

3. A method for fermenting Bacillus subtilis BS-TS1 according to claim 1, characterized in that: The Bacillus subtilis BS-TS1 according to claim 1 is inoculated into a fermentation substrate, and fermented at 30-40° C. for 48-96 hours; the fermentation speed is 120-200 r / min, and the pH of the fermentation substrate is 6.5-8.

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