Bacillus amyloliquefaciens xst2 and application thereof

Abstract

The present application relates to the field of microbial technology, and specifically discloses Bacillus amyloliquefaciens XST2 and application thereof. The present application finds a new Bacillus amyloliquefaciens XST2, which has a preservation number of CGMCC No. 33997. Fermentation of grains or legumes with the strain can improve volatile components, nutritional components and / or ACE inhibitory activity in the fermented product, thereby improving the efficacy and flavor of the product, and being suitable for application to food.

Description

Technical Field

[0001] This invention relates to the field of microbial technology, and more specifically, to Bacillus amyloliquefaciens XST2 and its applications. Background Technology

[0002] Bacillus amyloliquefaciens ( Bacillus amyloliquefaciens Belonging to the genus *Bacillus*, *Bacillus amyloliquefaciens* produces various enzymes and possesses diverse biological functions, finding applications in multiple fields. In agriculture, it has been used as a biofertilizer and biocontrol agent to promote plant growth, enhance plant resistance, and prevent soil-borne diseases. In environmental protection, it has been used to degrade pollutants in water. In animal production, it has been used to improve aquaculture water quality, enhance animal digestive enzyme activity, boost immunity, and improve intestinal mucosal antioxidant function, thereby promoting animal growth. In fruit and vegetable preservation, it has been used as an inhibitor of various fruit and vegetable pathogens.

[0003] Bacillus amyloliquefaciens is non-toxic and harmless to humans and animals and does not pollute the environment. However, it is still necessary to further develop Bacillus amyloliquefaciens with more efficacy and application methods. Summary of the Invention

[0004] One of the objectives of this invention is to provide a novel Bacillus amyloliquefaciens strain suitable for preparing fermented foods and its applications.

[0005] This invention provides a strain of Bacillus amyloliquefaciens (BAM) Bacillus amyloliquefaciens XST2, with accession number CGMCC No.33997.

[0006] This strain was deposited on March 27, 2025, at the China General Microbiological Culture Collection Center (CGMCC, address: No. 3, Courtyard 1, Beichen West Road, Chaoyang District, Beijing, Institute of Microbiology, Chinese Academy of Sciences, 100101, China) and classified as *Bacillus amyloliquefaciens*. Bacillus amyloliquefaciens The accession number is CGMCCNo. 33997.

[0007] The present invention also provides a bacterial agent containing the above-mentioned Bacillus amyloliquefaciens (B. amyloliquefaciens). Bacillus amyloliquefaciens XST2.

[0008] The bacterial agent of this invention contains Bacillus amyloliquefaciens (Bacillus amyloliquefaciens). Bacillus amyloliquefaciens XST2 may also contain other bacteria with similar or different functions. It may be a solid bacterial agent or a liquid bacterial agent. Those skilled in the art can prepare the bacterial agent according to methods known in the art.

[0009] This invention also provides the above-mentioned Bacillus amyloliquefaciens (B. amyloliquefaciens) Bacillus amyloliquefaciens XST2, or the application of microbial agents in fermenting grains or beans, preparing oat beverages, or inhibiting bacteria.

[0010] In the application of this invention, the grain is whole wheat, millet and / or oats; the legume is soybean; and the antibacterial target is Escherichia coli, Salmonella and / or Staphylococcus aureus.

[0011] The present invention also provides a fermented grain or legume, which is produced by the above-mentioned Bacillus amyloliquefaciens (Bacillus). Bacillus amyloliquefaciens Obtained by fermentation with XST2 or microbial agents.

[0012] The present invention also provides an oat beverage, which is made from the above-mentioned Bacillus amyloliquefaciens (BAM). Bacillus amyloliquefaciens It is made by pulping oats obtained through fermentation with XST2 or microbial agents.

[0013] The present invention also provides an antibacterial agent comprising the above-mentioned Bacillus amyloliquefaciens (Bacillus amyloliquefaciens). Bacillus amyloliquefaciens XST2 or bacterial agent.

[0014] This invention also provides the above-mentioned Bacillus amyloliquefaciens (B. amyloliquefaciens) Bacillus amyloliquefaciens XST2, or the application of microbial agents in any of the following aspects: (1) Enhance the volatile components, nutrients and / or ACE inhibitory activity in the products of soybean fermentation; (2) To enhance the volatile components and / or nutrients in the products of grain fermentation; (3) Reduce the aspect ratio of steamed buns containing fermented grains or beans and / or improve the specific volume, brightness and / or sensory evaluation of steamed buns containing fermented grains or beans; the fermented grains or beans are as described above; (4) Enhance the sensory evaluation of oat beverages, as described above.

[0015] In the application of this invention, when the legume is soybean, the volatile components include hexanol, hexanal, methyl acetate and / or butanol; the nutritional components include total phenols, flavonoids and / or ergosterol. When the grain is whole wheat, the volatile components include hexanol, methyl acetate, 2-methylpropionaldehyde and / or dimethyl sulfide; the nutrients include total phenols, flavonoids and / or ergosterol. When the grain is millet (preferably brown millet), the volatile components include amounts of pentanol, 1-propanol, furfural, 2-methylpropanol, 2-methyl-1-propanol, 2-methyl-2-propanol, 2-pentylfuran, and / or 3-methylbutanol; the nutrients include total phenols. When the grain is oats, the volatile components include ethyl acetate, pentanol, 3-methylbutanol, butanol and / or propionic acid.

[0016] In this invention, the above-mentioned strains or agents can appropriately increase the volatile components such as 2-methylpropionaldehyde and dimethyl sulfide after whole wheat fermentation, without producing off-odors, and provide a unique flavor to the fermentation products.

[0017] The present invention also provides a steamed bun containing fermented grains or beans; the fermented grains or beans are as described above; preferably, the grains are whole wheat and the beans are soybeans.

[0018] The beneficial effects of this invention are at least as follows: This invention provides a novel Bacillus amyloliquefaciens strain XST2, which can enhance the volatile components, nutrients, and / or ACE inhibitory activity in fermented grains or legumes, thereby improving the efficacy and flavor of the fermentation products, making it suitable for use in food. This enriches the range of fermentation strains for plant-based foods / beverages such as grains. Attached Figure Description

[0019] Figure 1 This is a phylogenetic tree.

[0020] Figure 2 The results are from the fingerprint analysis of volatile components in Example 3.

[0021] Figure 3 The results are from the fingerprint analysis of volatile components in Example 4.

[0022] Figure 4 The results are from the fingerprint analysis of volatile components in Example 8.

[0023] Figure 5 The results of the fingerprint analysis of volatile components in Example 9 are shown.

[0024] Figure 6 This is a diagram of the Circos genome.

[0025] Figure 7 The results are for carbohydrate activity enzyme analysis. This analysis includes glycoside hydrolase (GH), glycosyl transferase (GT), polysaccharide lyase (PL), carbohydrate esterase (CE), carbohydrate-binding module (CBM), and auxiliary activity enzyme (AA).

[0026] Figure 8 This is a linear diagram of gene clusters for the synthesis of secondary metabolites. Detailed Implementation

[0027] The preferred embodiments of the present invention will now be described in detail with reference to specific examples. It should be understood that the following examples are given for illustrative purposes only and are not intended to limit the scope of the invention. Those skilled in the art can make various modifications and substitutions to the present invention without departing from its spirit and essence.

[0028] Unless otherwise specified, the experimental methods used in the following examples are conventional methods. Unless otherwise specified, the materials and reagents used in the following examples are commercially available or prepared according to conventional methods in the art.

[0029] Example 1: Isolation and screening of Bacillus amyloliquefaciens In this embodiment, a strain of *Bacillus amyloliquefaciens* was obtained by screening using the dilution plate method, as follows: LB solid medium and plates were sterilized, and after sterilization, the LB medium was poured into the plates. Under aseptic conditions, 10g of traditional fermented food was taken, mixed evenly, and then 90 mL of sterile distilled water was added and shaken evenly to dilute to the initial 10g. -1 Then, it was continuously diluted to a final concentration of 10. -2 10 -3 10 -4 and 10 -5 , 10 -3 and 10 -5 Repeatedly streak plate separation with 20 μL of liquid until a single colony is obtained. Inoculate the single colony into a 2 mL cryovial containing 20% ​​glycerol using a sterile inoculation needle and store at -80°C for later use.

[0030] LB medium consisted of 10 g / L tryptone, 5 g / L yeast extract, 10 g / L sodium chloride, and 1 L distilled water. Solid medium was sterilized at 121 °C for 15 min with 15 g / L agar added.

[0031] A fast-growing strain of Bacillus amyloliquefaciens XST2 was selected for biological preservation, with the preservation number CGMCC No. 33997.

[0032] The genome of *Bacillus amyloliquefaciens* XST2 was extracted, and the 16S rRNA gene was amplified using PCR primers 27f and 1492r. BLAST (http: / / www.ncbi.nlm.nih.gov / BLAST) was used to identify the bacterial species with the highest homology to the target strain among those of known taxonomic positions. Gene sequences of known bacterial strains were selected from GenBank and compared with the 16S rRNA gene sequence of the target *Bacillus amyloliquefaciens* strain to determine their similar species and taxonomic position.

[0033] Specifically, based on 31 housekeeping genes (dnaG, frr, infC, nusA, pgk, pyrG, rplA, rplB, rplC, rplD, rplE, rplF, rplK, rplL, rplM, rplN, rplP, rplS, rplT, rpmA, rpoB, rpsB, rpsC, rpsE, rpsI, rpsJ, rpsK, rpsM, rpsS, smpB, tsf), 19 strains most closely related at the species level were selected, and a phylogenetic tree was constructed using the Neighbor-Joining (NJ) method with MEGA 6.0 software. The results are shown in […]. Figure 1 .

[0034] Example 2: Cultivation and observation of Bacillus amyloliquefaciens This embodiment studies the growth characteristics of Bacillus amyloliquefaciens XST2 obtained in Example 1.

[0035] 1. Bacillus amyloliquefaciens XST2 was cultured in LB medium, and its colony morphology was observed.

[0036] LB medium: 10g tryptone, 10g NaCl, 5g yeast extract, 1L distilled water; add 15g / L agar to solid medium, sterilize at 121℃ for 15 min.

[0037] 2. The antibacterial activity of Bacillus amyloliquefaciens XST2 was tested.

[0038] Detection method: In a sterile operating table, 10 μL of bacterial suspension (LB liquid medium, 37°C, culture for 48 h) was inoculated onto a sterile filter paper plate of bacterial agar evenly coated with pathogens, and placed in a 30 ℃ constant temperature incubator for 48 h. The inhibition zone of the colony was then observed and measured.

[0039] Specifically, *Bacillus amyloliquefaciens* XST2 exhibits antibacterial activity against *Escherichia coli*, *Salmonella*, and *Staphylococcus aureus*, with clear zone diameter to colony diameter ratios of 2.1 (against *Escherichia coli*), 1.3 (against *Staphylococcus aureus*), and 2.7 (against *Salmonella*). The same antibacterial experiment was conducted using the control bacterium *Bacillus amyloliquefaciens* AS1.892 (a related species, Beijing Biotechnology Collection Center), with clear zone diameter to colony diameter ratios of 1.2 (against *Escherichia coli*), 1.1 (against *Staphylococcus aureus*), and 1.3 (against *Salmonella*).

[0040] 3. The susceptibility of Bacillus amyloliquefaciens XST2 to different carbon sources and chemical sensitivities was tested. Results: After testing with the Biolog method, the carbon sources available were: dextrin, D-maltose, D-trehalose, D-cellobiose, sucrose, D-minobiose, raffinose, melibiose, β-formyl-D-glucoside, D-fructose, D-galactose, L-fructose, D-mannitol, D-gluconic acid, citric acid, γ-aminobutyric acid, and propionic acid.

[0041] Chemically sensitive substances: 1% NaCl, 1% sodium lactate, potassium tellurite.

[0042] Example 3: Study on volatile organic compounds of soybeans fermented using Bacillus amyloliquefaciens XST2 The *Bacillus amyloliquefaciens* XST2 culture was incubated in LB medium (pH 7) at 37°C for 48 h. The *Bacillus amyloliquefaciens* XST2 culture was added to cooked soybeans at a ratio of 1% (v / w, mL / g), and fermented at 25°C for 48 h. Volatile organic compounds (VOCs) were analyzed using GC-IMS (three biological replicates, XST2 group). The control bacterium *Bacillus amyloliquefaciens* AS1.892 (Beijing Biotechnology Collection Center) was cultured in LB medium and fermented in soybeans under the same conditions (BA group), and the results were analyzed under the same conditions (three biological replicates). A detailed list of VOCs from both groups is shown in Table 1. The results of the comparative analysis of VOC fingerprint spectra are shown in [Table 1]. Figure 2 .

[0043] Comparative analysis showed that, compared with the control group BA, Bacillus amyloliquefaciens XST2 produced higher levels of the following substances during fermentation: hexanol (fresh, fruity, alcoholic, sweet, and green aroma), hexanal (fresh, green aroma, fatty, and fruity aroma), methyl acetate (fruity aroma), and butanol (red wine aroma).

[0044] Table 1. List of Volatile Components Example 4: Study on the fermentation of whole wheat volatile organic compounds using Bacillus amyloliquefaciens XST2 The *Bacillus amyloliquefaciens* XST2 culture was incubated in LB medium (pH 7) at 37°C for 48 h. The *Bacillus amyloliquefaciens* XST2 culture was added to cooked whole wheat at a ratio of 1% (v / w, mL / g) and fermented at 25°C for 48 h. Volatile organic compounds (VOCs) were analyzed using GC-IMS (three biological replicates, XST2M group). The control bacterium *Bacillus amyloliquefaciens* AS1.892 (Beijing Biotechnology Center) was cultured in LB medium under the same conditions and fermented with soybeans (BAM group), and the results were analyzed under the same conditions (three biological replicates). A detailed list of VOCs from both groups is shown in Table 2. The results of the comparative analysis of VOC fingerprint spectra are shown in [Table 2]. Figure 3 .

[0045] The volatile substances in two different groups of samples were compared, and fingerprint analysis was performed on all volatile substances. The comparative analysis results showed that there were significant differences in the volatile substances between the two groups of samples. The substances with higher concentrations in the XST2M group mainly included: hexanol, methyl acetate, 2-methylpropionaldehyde (banana, melon, and a faint nutty aroma), and dimethyl sulfide (fermented aroma and marine flavor), which contribute to its unique flavor.

[0046] Table 2. List of Volatile Components Example 5: Fermentation of soybeans using Bacillus amyloliquefaciens XST2 to prepare whole wheat steamed buns In this embodiment, *Bacillus amyloliquefaciens* XST2 was cultured in LB medium (pH 7) at 37°C for 48 h. The *Bacillus amyloliquefaciens* XST2 culture was added to cooked soybeans at a ratio of 1% (v / w, mL / g), and fermented at 25°C for 48 h. The nutrient content was then analyzed. A control bacterium of the same genus, *Bacillus amyloliquefaciens* AS1.892 (Beijing Biotechnology Collection Center), was cultured in LB medium and soybeans were fermented under the same conditions. The nutrient content and ACE inhibitory activity were detected using commercially available kits. The average value of three tests was taken.

[0047] Total phenol content (mg / g): XST2: 6.9±0.3; BA: 6.6±0.4.

[0048] Flavonoid content (mg / g): XST2: 1.1±0.1; BA: 0.6±0.2.

[0049] Ergosterol (ug / g): XST2: 861.8±35.1; BA: 630.83±44.3.

[0050] ACE inhibitory activity (%): XST2: 62.00±3.68; BA: 59.96±1.79.

[0051] As can be seen from the above, the soybean products obtained by XST2 fermentation have a better content of nutrients.

[0052] Preparing whole wheat steamed buns: Soybean samples fermented with Bacillus amyloliquefaciens XST2 and soybean samples fermented with Bacillus amyloliquefaciens AS1.892 (BA) were dried in an oven at 55°C, ground into powder, and passed through an 80-mesh sieve. The fermented soybean powder was added to whole wheat flour at a mass fraction of 5% and mixed evenly. Whole wheat steamed buns without fermented soybean powder were made as a control. After kneading into dough, the dough was proofed for 1 hour, steamed for 25 minutes, and cooled to obtain whole wheat steamed buns.

[0053] The aspect ratio, specific volume, and color of the two types of steamed buns were tested, and sensory evaluation was conducted (specific standards are shown in Table 3). The results are shown in Tables 4 and 5.

[0054] Table 3 Sensory Evaluation Criteria for Steamed Buns Table 4 Table 5 Color saturation (average of 3 tests) Adding XST2 fermented soybean powder increases brightness and lightness.

[0055] Example 6: Fermentation of whole wheat using Bacillus amyloliquefaciens XST2 and preparation of whole wheat steamed buns In this embodiment, *Bacillus amyloliquefaciens* XST2 was cultured in LB medium (pH 7) at 37°C for 48 hours. The *Bacillus amyloliquefaciens* XST2 culture was added to cooked whole wheat at a ratio of 1% (v / w, mL / g), and fermented at 25°C for 48 hours. The nutrient content was then analyzed. A control strain of the same genus, *Bacillus amyloliquefaciens* AS1.892 (Beijing Biotechnology Collection Center), was cultured in LB medium under the same conditions and the whole wheat was fermented. The nutrient content was then analyzed. The average value of three measurements was taken.

[0056] Total phenol content (mg / g): XST2: 2.91±0.09; BA: 2.52±0.47.

[0057] Flavonoid content (mg / g): XST2: 0.78±0.05; BA: 0.65±0.04.

[0058] Ergosterol (ug / g): XST2: 61.76±5.83; BA: 22.91±6.96.

[0059] As can be seen from the above, the soybean products obtained by XST2 fermentation have a better content of nutrients.

[0060] Preparing whole wheat steamed buns: The whole wheat samples fermented by Bacillus amyloliquefaciens XST2 and the control Bacillus amyloliquefaciens AS1.892 (BA) were dried in an oven at 55°C, ground into powder, and passed through an 80-mesh sieve. The fermented whole wheat powder was added to the whole wheat powder at a mass fraction of 5% and mixed evenly. Whole wheat steamed buns without fermented whole wheat powder were made as a control. After kneading into dough, the dough was proofed for 1 hour, steamed for 25 minutes, and cooled to obtain whole wheat steamed buns.

[0061] The aspect ratio, specific volume, and color of the two types of steamed buns were tested, and sensory evaluation was conducted (specific standards are shown in Table 3). The results are shown in Tables 6 and 7.

[0062] Table 6 Table 7 Colorimetry (average of 3 tests) Adding XST2 fermented whole wheat flour will result in a lighter and brighter appearance.

[0063] Example 7: Fermentation of soybeans, whole wheat, and whole wheat steamed buns containing Bacillus amyloliquefaciens XST2. In this embodiment, *Bacillus amyloliquefaciens* XST2 was cultured in LB medium (pH 7) at 37°C for 48 hours. The *Bacillus amyloliquefaciens* XST2 culture was added to cooked soybeans at a ratio of 1% (v / w, mL / g), and fermented at 25°C for 48 hours. A control strain of the same genus, *Bacillus amyloliquefaciens* AS1.892 (Beijing Biotechnology Collection Center), was cultured in LB medium and soybeans were fermented under the same conditions.

[0064] In this embodiment, *Bacillus amyloliquefaciens* XST2 was cultured in LB medium (pH 7) at 37°C for 48 hours. The *Bacillus amyloliquefaciens* XST2 culture was added to the cooked whole wheat at a ratio of 1% (v / w, mL / g), and fermented at 25°C for 48 hours. A control strain of the same genus, *Bacillus amyloliquefaciens* AS1.892 (Beijing Biotechnology Collection Center), was cultured in LB medium and fermented with whole wheat under the same conditions.

[0065] Preparing whole wheat steamed buns: The fermented soybean sample and the fermented whole wheat sample were dried in an oven at 55°C, ground into powder, and passed through an 80-mesh sieve. Fermented soybean powder and fermented whole wheat powder were added to whole wheat flour at a mass fraction of 2.5% and mixed evenly. Whole wheat steamed buns without fermented soybean powder and whole wheat flour were made as a control. After kneading into dough, the dough was allowed to rise for 1 hour, steamed for 25 minutes, and cooled to obtain whole wheat steamed buns.

[0066] The aspect ratio, specific volume, and color of the two types of steamed buns were tested, and sensory evaluation was conducted (specific standards are shown in Table 3). The results are shown in Tables 8 and 9.

[0067] Table 8 Table 9 Color saturation (average of 3 tests) Adding XST2 baking powder will make the color lighter and brighter.

[0068] Example 8 Study on volatile organic compounds of brown millet fermented using Bacillus amyloliquefaciens XST2 The *Bacillus amyloliquefaciens* XST2 culture was incubated in LB medium (pH 7) at 37°C for 48 h. The *Bacillus amyloliquefaciens* XST2 culture was added to cooked brown millet at a ratio of 1% (v / w, mL / g) and fermented at 25°C for 48 h. Volatile organic compounds (VOCs) were analyzed using GC-IMS (three biological replicates, XST2XM group). The control bacterium *Bacillus amyloliquefaciens* AS1.892 (Beijing Biotechnology Center) was cultured in LB medium and fermented in brown millet under the same conditions (BAXM group), and analysis was performed under the same conditions (three biological replicates). A detailed list of VOC components for both groups is shown in Table 10. The results of the comparative analysis of VOC fingerprint spectra are shown in [Table 10]. Figure 4 .

[0069] The volatile substances in the two groups of samples were compared, and fingerprint analysis was performed on all volatile substances. The results showed that there were significant differences in the volatile substances between the two groups. Substances with higher concentrations in the XST2XM group included: pentanol, 1-propanol, furfural, 2-methylpropanol, 2-methyl-1-propanol, 2-methyl-2-propanol, 2-pentylfuran, and 3-methylbutanol.

[0070] Table 10 Detailed List of Volatile Components In this embodiment, the total phenol content (mg / g) of the XST2XM group and the BAXM group samples was further detected. The results were: XST2 group: 4.03±0.16; BAXM group: 1.49±0.21.

[0071] Example 9: Study on the fermentation of volatile organic compounds in whole oats using Bacillus amyloliquefaciens XST2 and its application in beverage preparation. The *Bacillus amyloliquefaciens* XST2 culture was incubated in LB medium (pH 7) at 37°C for 48 h. The *Bacillus amyloliquefaciens* XST2 culture was added to cooked oats at a ratio of 1% (v / w, mL / g) and fermented at 25°C for 48 h. Volatile organic compounds (VOCs) were analyzed using GC-IMS (three biological replicates, XST2YM group). The control bacterium *Bacillus amyloliquefaciens* AS1.892 (Beijing Biotechnology Center) was cultured in LB medium under the same conditions and oats were fermented (BAYM group), and the results were analyzed under the same conditions (three biological replicates). A detailed list of VOC components for both groups is shown in Table 11. The results of the comparative analysis of VOC fingerprint spectra are shown in... Figure 5 .

[0072] The volatile substances in the two groups of samples were compared, and fingerprint analysis was performed on all volatile substances. The results showed that there were significant differences in the volatile substances between the two groups. The substances with higher concentrations in the XST2YM group included: ethyl acetate (fresh, fruity, sweet, and grassy), pentanol (balsamic, floral, and alcoholic), 3-methylbutanol (whiskey and banana aromas), butanol (red wine flavor), and propionic acid (yogurt and vinegar flavors).

[0073] Table 11 Detailed List of Volatile Components In this embodiment, the above two groups of fermented oat samples were further prepared into a blended beverage and subjected to sensory evaluation. The scoring criteria are shown in Table 12.

[0074] Table 12 A 10% (fermented sample / pure water) blended beverage was prepared by fermenting oats with 20% XST2YM group fermented oats + 80% Pediococcus pentosaceus HNTP (preservation number CGMCC No. 29067). The sensory score was 85.2 ± 3.5.

[0075] A 10% (fermented sample / pure water) blended beverage was prepared using 20% ​​BAYM group of control bacteria fermented oats + 80% Pediococcus pentosaceus HNTP (preservation number CGMCC No.29067) fermented oats, with a sensory score of 78.3 ± 2.8.

[0076] A 10% (fermented sample / pure water) blended beverage was prepared by fermenting oats with 10% XST2YM group fermented oats + 80% Pediococcus pentosaceus HNTP (preservation number CGMCC No. 29067) fermented oats + 10% Saccharomyces cerevisiae fermented oats, and the sensory score was 88.6 ± 4.2.

[0077] A 10% (fermented sample / pure water) blended beverage was prepared by fermenting oats with 10% BAYM control group + 80% Pediococcus pentosaceus HNTP (preservation number CGMCC No.29067) + 10% Saccharomyces cerevisiae fermented oats. The sensory score was 79.1 ± 3.6.

[0078] Pediococcus pentosaceus HNTP was deposited on November 20, 2023, at the China General Microbiological Culture Collection Center (CGMCC, No. 3, Courtyard 1, Beichen West Road, Chaoyang District, Beijing, Institute of Microbiology, Chinese Academy of Sciences, 100101, China), and classified as Pediococcus pentosaceus, with accession number CGMCC No. 29067.

[0079] The methods for fermenting oats with Pediococcus pentosacchari HNTP and Saccharomyces cerevisiae are the same as those for Bacillus amyloliquefaciens XST2.

[0080] Example 10: Genomic analysis of Bacillus amyloliquefaciens XST2 This embodiment analyzed the genome of Bacillus amyloliquefaciens XST2, and the results are shown in Table 13. Figures 6 to 8 .

[0081] Table 13 The results of the Circos genome mapping analysis are shown below. Figure 6 The results of carbohydrate activity enzyme analysis are shown in [the table below]. Figure 7 The linear map of the gene clusters for secondary metabolite synthesis is shown below. Figure 8 .

[0082] Although the present invention has been described in detail above with general descriptions and specific embodiments, modifications or improvements can be made to it, which will be obvious to those skilled in the art. Therefore, all such modifications or improvements made without departing from the spirit of the present invention fall within the scope of protection claimed by the present invention.

Claims

1. A strain of Bacillus amyloliquefaciens ( Bacillus amyloliquefaciens XST2, characterized in that, The accession number is CGMCC No. 33997.

2. A microbial agent, characterized in that, Contains the Bacillus amyloliquefaciens as described in claim 1 ( Bacillus amyloliquefaciens XST2.

3. The Bacillus amyloliquefaciens according to claim 1 ( Bacillus amyloliquefaciens XST2, or the use of the microbial agent according to claim 2 in fermenting grains or beans, preparing oat beverages, or inhibiting bacteria.

4. The application according to claim 3, characterized in that, The grains are whole wheat, millet, and / or oats; the legumes are soybeans; and the antibacterial targets are Escherichia coli, Salmonella, and / or Staphylococcus aureus.

5. A fermented grain or legume, characterized in that, The Bacillus amyloliquefaciens as described in claim 1 ( Bacillus amyloliquefaciens XST2, or obtained by fermentation of the microbial agent as described in claim 2.

6. An oatmeal beverage, characterized in that, The Bacillus amyloliquefaciens as described in claim 1 ( Bacillus amyloliquefaciens It is made from oat pulp obtained by fermentation with the microbial agent described in claim 2, or XST2.

7. An antibacterial agent, characterized in that, Contains Bacillus amyloliquefaciens as described in claim 1 ( Bacillus amyloliquefaciens XST2, or the bacterial agent as described in claim 2.

8. The Bacillus amyloliquefaciens according to claim 1 ( Bacillus amyloliquefaciens The use of XST2, or the microbial agent according to claim 2, in any of the following aspects: (1) Enhance the volatile components, nutrients and / or ACE inhibitory activity in the products of soybean fermentation; (2) To enhance the volatile components and / or nutrients in the products of grain fermentation; (3) Reduce the aspect ratio of steamed buns containing fermented grains or beans and / or improve the specific volume, brightness and / or sensory evaluation of steamed buns containing fermented grains or beans; wherein the fermented grains or beans are as described in claim 5; (4) Enhance the sensory evaluation of oat beverages, as described in claim 6.

9. The application according to claim 8, characterized in that, When the legume is soybean, the volatile components include hexanol, hexanal, methyl acetate and / or butanol; the nutritional components include total phenols, flavonoids and / or ergosterol. When the grain is whole wheat, the volatile components include hexanol, methyl acetate, 2-methylpropionaldehyde and / or dimethyl sulfide; the nutrients include total phenols, flavonoids and / or ergosterol. When the grain is millet, the volatile components include amounts of pentanol, 1-propanol, furfural, 2-methylpropanol, 2-methyl-1-propanol, 2-methyl-2-propanol, 2-pentylfuran, and / or 3-methylbutanol; the nutrients include total phenols. When the grain is oats, the volatile components include ethyl acetate, pentanol, 3-methylbutanol, butanol and / or propionic acid.

10. A type of steamed bun, characterized in that, Contains fermented grains or legumes; said fermented grains or legumes as described in claim 5; preferably, the grains are whole wheat and the legumes are soybeans.

Images