Bacillus velezensis and application thereof

Abstract

The invention relates to the technical field of biodegradation, and provides bacillus velezensis and application thereof. The bacillus velezensis is bacillus velezensis MB-NM-3 and is preserved in the China General Microbiological Culture Collection Center on November 4, 2024, the preservation address is Institute of Microbiology, Chinese Academy of Sciences, Beichen West Road, Chaoyang District, Beijing, and the preservation number is CGMCC No.32480. The bacillus velezensis MB-NM-3 disclosed by the invention can be used for preparing the bacillus velezensis. According to the technical scheme, the problem that the degradation rate of existing microorganisms on lignite is low in the prior art is solved.

Description

Technical Field

[0001] The invention relates to the technical field of biodegradation, and in particular to Bacillus velezinus and application thereof. Background Art

[0002] Humic acid is a natural high molecular organic mixture, which is widely used in various aspects such as industry, agriculture, and forestry. It is widely distributed in soil, water bodies, peat, lignite, and weathered coal. China is a major coal producer, with proven reserves ranking third in the world. Among them, the proven reserves of lignite are 130.3 billion tons, accounting for nearly 13% of the country's coal reserves. Due to its high moisture content, high ash content, high volatile matter, and low calorific value, lignite has low thermal efficiency when directly burned, and it is extremely polluting, so it has not been effectively utilized. Therefore, the method of microbial conversion of coal (or microbial dissolution of coal, microbial degradation of coal) is adopted, and the action of microorganisms such as fungi, bacteria, and actinomycetes is used to achieve the dissolution, degradation, liquefaction or gasification of coal to obtain clean fuels and other chemicals. This process has a series of advantages such as simple equipment requirements, mild conversion conditions, and low energy consumption. However, the efficiency of lignite degradation in existing microorganisms is relatively low, so it is crucial to screen and cultivate microbial strains with high lignite degradation ability. Summary of the invention

[0003] The invention provides a Velez subspore and application thereof, which solves the problem of low lignite degradation rate of existing microorganisms in the related art.

[0004] The technical solution of the present invention is as follows: The present invention provides a Velez subtilis bacillus, wherein the Velez subtilis bacillus is Velez subtilis bacillus ( Bacillus velezensis ) MB-NM-3, deposited on November 4, 2024 in the General Microbiology Center of China Microbiological Culture Collection Administration, the deposit address is Institute of Microbiology, Chinese Academy of Sciences, Beichen West Road, Chaoyang District, Beijing, and the deposit number is CGMCC No.32480.

[0005] As a further technical solution, the Velez Bacillus ( Bacillus velezensis ) The 16S rDNA gene sequence of MB-NM-3 is shown in SEQ ID NO.1.

[0006] The present invention also provides a microbial agent, wherein the microbial agent comprises the Bacillus Velezii ( Bacillus velezensis )MB-NM-3.

[0007] As a further technical solution, the microbial agent also includes but is not limited to one or more of nitrogen-fixing bacteria, Bacillus, actinomycetes, phosphate-dissolving bacteria, and phosphate-dissolving fungi.

[0008] As a further technical solution, the microbial agent also includes one or more of a carrier, a nutrient, and an auxiliary agent.

[0009] As a further technical solution, when the microbial agent includes a carrier, the carrier includes but is not limited to one or more of diatomaceous earth, montmorillonite, kaolin, white carbon, light calcium carbonate, rice husk, sawdust, starch, polyvinyl alcohol, and polyethylene glycol.

[0010] As a further technical solution, when the microbial agent includes nutrients, the nutrients include but are not limited to one or more of salts, minerals, amino acids, sugars, yeast extracts, and trace elements.

[0011] As a further technical solution, when the microbial agent includes an auxiliary agent, the auxiliary agent includes but is not limited to one or more of a solvent, a pH regulator, a dispersant, an emulsifier, a preservative, a moisturizer, and a wetting agent.

[0012] As a further technical solution, the Velez Bacillus ( Bacillus velezensis )The live bacterial count of MB-NM-3 is 10 7 ~10 11 CFU / g or 10 7 ~10 11 CFU / mL.

[0013] The invention also provides an application of Bacillus Velez or a microbial agent in degrading lignite.

[0014] As a further technical solution, when degrading the lignite, the lignite does not need to undergo any pretreatment.

[0015] The invention also provides an application of Bacillus Velez or a microbial agent in resisting pathogenic fungi.

[0016] The invention also provides an application of Bacillus Velez or a microbial agent in salt-alkali resistance.

[0017] The invention also provides an application of Bacillus Velez or a microbial agent in producing extracellular polysaccharide and improving soil aggregate structure.

[0018] The invention also provides an application of Bacillus Velez or a microbial agent in degrading organic matter.

[0019] As a further technical solution, the organic matter includes one or more of cellulose, protein, lipid, and starch.

[0020] In the present invention, Bacillus Velez subtilis MB-NM-3 or a microbial agent containing Bacillus Velez subtilis MB-NM-3 is applied to degrade cellulose, which can promote the efficient and pollution-free degradation of cellulose, and promote the treatment and recycling of waste containing cellulose, such as the treatment of agricultural waste (such as plant straw). And based on the good ability of Bacillus Velez subtilis MB-NM-3 to degrade protein, lipid, inorganic phosphorus and starch, Bacillus Velez subtilis MB-NM-3 or a microbial agent containing Bacillus Velez subtilis MB-NM-3 can effectively degrade waste or organic fertilizer containing at least one of cellulose, protein, fat, inorganic phosphorus and starch, thereby improving the treatment efficiency and comprehensive utilization of organic matter containing complex components.

[0021] The working principle and beneficial effects of the present invention are: The Velez Bacillus MB-NM-3 obtained by the present invention through a lignite shake flask degradation test in the soil of Chayouzhong Banner, Ulanqab City, Inner Mongolia Autonomous Region can achieve a release rate of 8.41% of humic acid after being shaken and cultured at 30°C for 7 days and then treated at 120°C for 20 minutes when degrading lignite, thereby improving the degradation rate of lignite.

[0022] The Bacillus Velez MB-NM-3 strain can not only degrade lignite, but also has the ability to produce extracellular polysaccharides, degrade inorganic phosphorus, and degrade organic matter; it is also a salt- and alkali-tolerant multifunctional strain with broad application prospects. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] The present invention will be further described in detail below in conjunction with the accompanying drawings and specific embodiments.

[0024] Figure 1 The color reduction reaction of Bacillus Velez MB-NM-3 in Example 1 in different culture media; In the figure, a contains aniline blue; b contains azure B; c contains Coomassie brilliant blue; Figure 2 This is a comparison diagram of the supernatant after high temperature treatment in the lignite degradation shake flask experiment in Example 2; In the figure: the left picture is the control, and the right picture is the MB-NM-3 strain; Figure 3 is the phylogenetic tree of Bacillus Velez subtilis MB-NM-3 in Example 3; Figure 4 The morphology of Bacillus Velez MB-NM-3 in Example 4 on R2A medium; Figure 5 The resistance test of Bacillus Velez MB-NM-3 to different pathogenic fungi in Example 5; In the figure, a: cotton wilt pathogen; b: wheat sheath blight pathogen; c: wheat root rot pathogen; d: gray mold pathogen; e: pear black spot pathogen; f: apple leaf spot pathogen; g: wheat fusarium rust pathogen; h: tomato early blight pathogen; i: wheat stem base rot pathogen; Figure 6 The growth conditions of Bacillus Velez MB-NM-3 under different conditions in Example 6; In the figure, a: 45℃; b: pH5; c: pH10; d: adding 5% NaCl; e: adding 10% NaCl; f: adding 5% KNO3; g: adding 10% KNO3; Figure 7 is the degradation ability of Bacillus Velezii MB-NM-3 in Example 7 on lipids, proteins, cellulose, starch, and inorganic phosphorus substances; In the figure, a: lipid culture medium; b: protein culture medium; c: CMC culture medium; d: soluble protein culture medium; e: inorganic phosphorus culture medium; Figure 8 The figure shows the effect of different treatments on the proportion of soil water-stable aggregates (>0.25 mm) in Example 9.

[0025] Description of biological material deposit The present invention provides the Bacillus Velezii ( Bacillus velezensis ) MB-NM-3, deposited in the General Microbiology Center of China Microbiological Culture Collection Administration, the deposit address is Institute of Microbiology, Chinese Academy of Sciences, Beichen West Road, Chaoyang District, Beijing, the deposit number is CGMCC No.32480, and the deposit date is November 4, 2024. DETAILED DESCRIPTION

[0026] The following will be combined with the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0027] Example 1 Screening of microorganisms capable of degrading lignite 1. Sample source: The soil samples for this experiment were collected from Chayouzhong Banner, Ulanqab City, Inner Mongolia Autonomous Region; 2. Screening of target microorganisms: Dilute the soil sample and apply it on the screening medium (10g yeast powder, 20g glucose, 0.1g aniline blue, 18g agar, 1L distilled water), and culture it at 30℃ for 2 days. Pick the strain that can change the color of the medium and culture it on R2A medium (0.5g yeast powder, 0.5g tryptone, 0.5g peptone, 0.5g glucose, 0.5g soluble starch, 0.3g dipotassium hydrogen phosphate, 0.3g sodium pyruvate, 15g agar, 1L water) at 30℃ for 2 days; 3. Repeated verification of microbial function: After the strain was extracted and purified, it was inoculated on three different screening culture media containing aniline blue, Azure B, and Coomassie Brilliant Blue (10 g yeast powder, 20 g glucose, 0.1 g aniline blue / Azure B / Coomassie Brilliant Blue, 18 g agar, and 1 L distilled water), and the color reduction reaction of the strain was observed to perform functional rescreening; taking the MB-HM-3 strain of the present invention as an example, the color reduction reaction in different culture media was as follows: Figure 1 shown.

[0028] Example 2 Lignite shake flask degradation test The strain screened in Example 1 was inoculated into a 250 mL shake flask containing 50 mL of nutrient-deficient R2A medium (0.5 g yeast powder, 0.75 g peptone, 0.5 g glucose, 0.3 g dipotassium hydrogen phosphate, 0.3 g sodium pyruvate, 1 L water, pH 7.0) containing 0.25 g lignite, and a negative control without inoculation was set up. The culture was shaken at 30°C for 7 days, and then treated at 120°C for 20 min. The humic acid content in the supernatant was measured again, and the conversion rate was calculated. The test results of the MB-NM-3 strain and the control are shown in Figure 2. Figure 2 As shown. The humic acid determination and calculation formula are carried out in accordance with the industry standard "NYT1971-2010 Determination of Humic Acid Content in Water-soluble Fertilizers"; The test results are as follows: In this experiment, five strains with lignite degradation function were screened from soil samples collected from Chayouzhong Banner, Ulanqab City, Inner Mongolia Autonomous Region. The lignite used in this experiment was not pretreated, and the reaction system was 5g / 1000mL; the effects of different strains on lignite degradation are shown in Table 1.

[0029] Table 1 Effect of strains on lignite degradation

[0030] As shown in Table 1, the humic acid release rate of MB-NM-3 was 8.41% through the lignite shake flask degradation test, which was higher than the humic acid release rates of MB-NM-1, MB-NM-2, MB-NM-4 and MB-NM-5 strains, indicating that the MB-NM-3 strain had a higher degradation rate for lignite. Therefore, the MB-NM-3 strain was identified and preserved.

[0031] Example 3 Bacterial species identification 1. Extraction of bacterial DNA by CTAB method: inoculate a single colony in 5mL R2A liquid (0.5g yeast powder, 0.5g tryptone, 0.75g peptone, 0.5g glucose, 0.5g soluble starch, 0.3g dipotassium hydrogen phosphate, 0.3g sodium pyruvate, 1L water), and culture at 30℃ for 24h to obtain seed culture solution; take 1mL seed culture solution and inoculate it in 100mL R2A liquid, and culture it at 37℃ and 220r / min for 16h; centrifuge at 5000r / min for 10 minutes, and discard the supernatant; add 10mL TE for centrifugation and washing, dissolve the bacteria with 10mL TE, mix well, and store at -20℃ for later use; take 3.5mL bacterial suspension, add 184μL 10% SDS (w / v), mix well, add 37μL 10mg / mL proteinase K, mix well, and incubate at 37℃ for 1 hour; add 740μL 5mol / LNaCl, then add 512μL CTAB / NaCl, mix well, and incubate at 65℃ for 10 minutes; add an equal volume of chloroform / isoamyl alcohol (volume ratio of 24:1), mix well, centrifuge at 10000r / min for 5 minutes, and retain the supernatant; add an equal volume of a mixture of phenol: chloroform: isoamyl alcohol (volume ratio of 25:24:1) to the supernatant, mix well, centrifuge at 10000r / min for 5 minutes, and retain the supernatant; add 0.6 times the volume of isopropanol, mix well, centrifuge at 10000r / min for 5 minutes, collect the DNA precipitate, and wash the DNA precipitate by centrifugation with 70% volume fraction of ethanol; dissolve the DNA with 1mL TE, add RNaseA at a final concentration of 20μg / mL, and store at 4℃; 2. Amplification and sequencing 16S rDNA universal primers 27f (5'-AGAGTTTGATCCTGGCTCAG-3') and 1492r (5'-GGTTACCTTGTTACGACTT-3') were used for PCR amplification of 16S rDNA. PCR reaction system: Taq PCR Master Mix 20μL, primers 0.8μL each, DNA template 1μL, ddH2O 17.4μL. PCR reaction conditions: 94℃ pre-denaturation for 30s; 94℃ denaturation for 30s, 55℃ annealing for 30s, 72℃ extension for 60s, 35 cycles, 72℃ extension for 10min. The PCR product was subjected to 1.0% (w / v) agarose gel electrophoresis. After agarose gel electrophoresis, the PCR product was recovered, purified and sequenced (Shanghai Sangon Biotechnology Co., Ltd.). Based on the obtained 16S rDNA sequence, the homologous sequence was searched in GenBank by Blast. The results showed that it was consistent with Bacillus velezinsis ( Bacillus velezensis) homology is as high as 100%, and the 16S rDNA sequence of MB-NM-3 strain is shown in the sequence table SEQID No.1; the phylogenetic tree was established by MEGA7.0 software, and the phylogenetic tree is shown in Figure 3 shown.

[0032] Example 4 Strain morphology observation The screened MB-NM-3 strain was inoculated onto the R2A plate and cultured at 30°C for 48 h. The size, shape, color, glossiness, ridge shape, transparency, edge characteristics, etc. of the colonies were observed.

[0033] Results: By Figure 4 It can be seen that after the strain grew on R2A medium for 2 days, the colonies were round, with irregular edges, white and opaque, and a dry and matte surface. The colony diameter was about 5~6mm.

[0034] Example 5 Antifungal activity of strains The functional strains screened and sequenced to be safe were subjected to a plate confrontation test with the existing fungi in the laboratory. An 8mm pathogenic fungus cake was punched with a hole puncher and inoculated in the middle of a PDA medium (200g potato, 20g glucose, 15-20g agar, 1000mL water). In a cross shape, a 10μL inoculation loop was used to pick Bacillus Velez MB-NM-3 (abbreviated as NM-3) and inoculated at a distance of 2.5cm from the pathogenic fungus. The functional strains were cultured at 28°C to determine their resistance to pathogenic fungi. The results of the strains' resistance to different pathogenic fungi are shown in the figure. Figure 5 As shown. The fungi currently available in the laboratory include: Cotton wilt pathogen ( Fusarium oxysporum )、Triticum solani ( Rhizoctonia cereals ), wheat root rot pathogen ( Bipolaris sorokiniana )、Botrytis cinerea( Botrytis cinerea )、Pear Black Spot Fungus( Alternaria ), Apple leaf spot pathogen ( Alternaria brassicae )、Triticum fusarium ( Fusahum graminearum )、Tomato early blight pathogen ( Altemaria solani ), wheat stem rot fungus ( Fusarium pseudograminearum ).

[0035] Depend on Figure 5 It can be known that the strain of the present invention has obvious antagonistic effects on cotton wilt, wheat eyebrow rust, wheat root rot, gray mold, pear black spot, apple leaf spot, wheat head blight, tomato early blight and wheat stem base rot.

[0036] Example 6 Determination of strain stress resistance The strains screened were picked up with a 10uL inoculation loop and inoculated onto R2A medium at 45°C, pH 5, pH 10, 5% NaCl, 10% NaCl, 5% KNO3, and 10% KNO3 (content calculated by w / v) to observe whether the strains grew, whether the growth was inhibited, and the growth rate. Figure 6 shown.

[0037] Depend on Figure 6 It can be seen that the Bacillus Velez subtilis MB-NM-3 strain in the present invention can grow normally on the R2A culture medium with the conditions of 45°C, pH5, pH10, 5% NaCl, 5% KNO3, and 10% KNO3. The growth on the R2A culture medium with the condition of 10% NaCl is inhibited to a certain extent, but it can still grow, indicating that the strain has good stress resistance.

[0038] Example 7 Determination of the ability of strains to degrade lipids, proteins, cellulose, starch, and inorganic phosphorus The Velezella MB-NM-3 cultured on R2A medium for 1 day was inoculated on the medium containing different substances. After culturing at 30℃ for 2 days, the diameter of the degradation zone was measured in mm. The measurement results are as follows: Figure 7 And as shown in Table 2.

[0039] Degradability formula: Degradation capacity = diameter of functional medium degradation zone in millimeters + X; X is the weighting coefficient, which is -2, -1, 0, 1, and 2 according to the transparency of the strain's silicon ring; Formula of each functional culture medium: Lipid culture medium: 10 g / L tributyrin + R2A solid culture medium; Protein medium: 5g / L skim milk powder + R2A solid medium; Cellulose (CMC) medium: potassium hydrogen phosphate 1.0 g, magnesium sulfate heptahydrate 0.25 g, yeast extract 2.0 g, agar powder 10.0 g, CMC 2.0 g, distilled water 1000 mL; Soluble starch medium: beef extract 5.0g, peptone 10.0g, sodium chloride 5.0g, soluble starch 2.0g, agar powder 20.0g, distilled water 1000mL; Inorganic phosphorus culture medium: yeast 0.5g, glucose 10.0g, ammonium sulfate 0.5g, potassium chloride 0.02g, magnesium sulfate heptahydrate 0.1g, ferrous sulfate 0.2mg, manganese sulfate 4mg, agar powder 15.0g, tricalcium phosphate 5.0g (prepared separately), distilled water 1000mL.

[0040] Table 2 Degradation ability of Bacillus velez MB-NM-3

[0041] Depend on Figure 7 It can be clearly seen from Table 2 that the Bacillus Velezii MB-NM-3 of the present invention has obvious degradation effects on lipids, proteins, cellulose, starch and inorganic phosphorus.

[0042] Example 8 Screening of culture medium for producing exopolysaccharide Method for determination of extracellular polysaccharides: ① Centrifuge the above fermentation broth at 3000r / min for 10min to remove the bacteria; ② Take 2ml of supernatant in a 50ml centrifuge tube, add 3 times the volume of anhydrous ethanol, 4℃, 1h, 4000r / min centrifuge for 5min, and discard the supernatant; ③ Wash the precipitate with 10ml of 80% ethanol solution, centrifuge and discard the supernatant; ④ Dissolve the precipitate with water, transfer it to a 100ml volumetric flask, and make up to volume; ⑤ Determine the content of extracellular polysaccharides by sulfuric acid-phenol method.

[0043] Based on the initial culture medium (1L, including 20g sucrose, 3g yeast powder, 2.6g KH2PO4, 0.5g CaCl2, 2g MgSO4, 1mg FeSO4, and the rest is water), different liquid culture media containing sucrose and glucose were prepared at 20g / L to determine the optimal carbon source; different liquid culture media containing yeast powder, peptone, KNO3, and (NH4)2SO4 were prepared at 3g / L to determine the optimal nitrogen source.

[0044] According to the results of previous experiments, the most suitable carbon and nitrogen sources for MB-NM-3 are sucrose and yeast powder. Through experiments on the addition of sucrose, yeast powder and different organic salts, the most suitable culture medium for MB-NM-3 to produce extracellular polysaccharides was initially obtained. Among them, the components of different culture media are described as follows.

[0045] Culture medium 1: 1L, including sucrose 45g, yeast powder 3g, KH2PO42.6g, CaCl20.5g, MgSO42g, FeSO41mg, the balance is water; Medium 2: 1L, including sucrose 45g, yeast powder 6g, KH2PO42.6g, CaCl20.5g, MgSO42g, FeSO41mg, the balance is water; Medium 3: 1L, including sucrose 45g, yeast powder 6g, KH2PO44g, CaCl20.5g, MgSO42g, FeSO41mg, the balance is water; Culture medium 4: 1L, including sucrose 45g, yeast powder 6g, KH2PO44g, CaCl20.25g, MgSO42g, FeSO41mg, and the balance is water; Culture medium 5: 1L, including sucrose 45g, yeast powder 6g, KH2PO44g, CaCl20.25g, MgSO42g, FeSO41.5mg, and the balance is water; Culture medium 6: 1 L includes 45 g sucrose, 6 g yeast powder, 4 g KH2PO4, 0.5 g CaCl2, 3 g MgSO4, 1.5 mg FeSO4, and the balance is water.

[0046] Under the culture conditions of 30°C and 200 r / min, the culture was carried out for 72 hours. After measurement, the statistical table of the extracellular polysaccharide content produced by MB-NM-3 in different culture media is shown in Table 3 below.

[0047] Table 3 Extracellular polysaccharide content produced in different culture media

[0048] As shown in Table 3, the most suitable culture medium for MB-NM-3 to produce extracellular polysaccharides is formula 6: sucrose 45g, yeast powder 6g, KH2PO44g, CaCl20.5g, MgSO43g, FeSO41.5mg, H2O 1000mL, and the measured polysaccharide content can reach 12.21mg / mL.

[0049] Example 9 Effects of bacterial strains and extracellular polysaccharides on the aggregate structure of water-stable soil Soil aggregates are the basic units of soil structure and an important indicator for measuring soil erosion. Soil aggregates are usually divided into two categories: macroaggregates > 0.25 mm and microaggregates < 0.25 mm. Water-stable aggregates > 0.25 mm are generally called soil aggregate structures and are used as indicators for evaluating soil aggregates.

[0050] 1. Experimental treatment The test strain was activated on R2A medium, and then the activated strain was inoculated into the extracellular polysaccharide production medium (Example 7), and cultured at 30°C and 200r / min for 48h, and the fermentation liquid was taken out and centrifuged at 4000r / min for 5min to collect the bacteria. The bacteria were washed twice with sterile deionized water, resuspended in sterile deionized water to make its OD600 0.005 (about 106 / mL), which was a bacterial suspension, and divided into two parts, one for live bacterial suspension and the other for sterilization at 121°C for 30min, which was an inactivated bacterial suspension for standby use. The culture medium in Example 7 was used for fermentation, and the extracellular polysaccharides were extracted to prepare extracellular polysaccharide liquids with different contents for standby use.

[0051] The experiment set up controls of live bacteria, inactivated bacteria, 1.4 mg / g extracellular polysaccharide, 2.8 mg / g extracellular polysaccharide and equal amount of sterile water, with a total of 5 groups of treatments, and three replicates for each treatment. Weigh the soil that has passed through a 0.25 mm sieve and put it into a plate, and label the plate to indicate the group. Take 5 mL of sterile water, live bacteria suspension, inactivated bacteria suspension, and extracellular polysaccharide solution of different concentrations, and add them to the corresponding plates. Place the plate on a light culture rack and culture at 20-30 ° C. During the culture period, add deionized water regularly to keep the soil surface moist. After 30 days of culture, the treatment was carried out.

[0052] 2. Determination method Weigh 20g of undisturbed soil from the flat dish, keep the soil in its original state, place it in a measuring cylinder, and slowly add deionized water along the wall of the measuring cylinder until saturated. Transfer the saturated soil sample to the top of the sieve placed in a bucket and oscillate until the soil particles on the sieve are clearly visible on the water surface and no longer pass through the sieve holes. Collect the soil samples above and below the sieve separately, dry and weigh them. The sample above the sieve is the water-stable aggregate >0.25mm, and the sample below the sieve is the water-stable aggregate <0.25mm. The effects of different treatments on the proportion of soil water-stable aggregates (>0.25mm) are shown in Tables 4 and Figure 8 shown.

[0053] Table 4 Effects of different treatments on the proportion of soil water-stable aggregates (>0.25 mm)

[0054] Note: * indicates that there is a significant difference between the control and the treatment, ** indicates that there is a very significant difference between the control and the treatment.

[0055] As shown in Table 4, in different treatments, there are extremely significant differences between each treatment and the control. After the 1.4 mg / g extracellular polysaccharide treatment, the proportion of soil> 0.25 mm water-stable aggregates increased the most, 11.22 times higher than the control. After the 2.8 mg / g extracellular polysaccharide treatment, the proportion of soil> 0.25 mm water-stable aggregates increased 9.66 times higher than the control. The proportion of soil> 0.25 mm water-stable aggregates treated with live bacteria increased 3.82 times higher than the control. This shows that the Bacillus Velez MB-NM-3 strain and the extracellular polysaccharides produced by the strain in the present invention can promote the formation of soil> 0.25 mm water-stable aggregates.

[0056] The above are only preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A Bacillus Velez, characterized in that The Velez Bacillus is Velez Bacillus ( Bacillus velezensis ) MB-NM-3, deposited on November 4, 2024 in the General Microbiology Center of China Microbiological Culture Collection Administration, the deposit address is Institute of Microbiology, Chinese Academy of Sciences, Beichen West Road, Chaoyang District, Beijing, and the deposit number is CGMCC No.32480.

2. The Bacillus Velezii according to claim 1, characterized in that The Bacillus Velez Bacillus velezensis ) The 16S rDNA gene sequence of MB-NM-3 is shown in SEQ ID NO.

1.

3. A microbial agent, characterized in that: The microbial agent comprises the Bacillus Velezii described in claim 1 or 2 ( Bacillus velezensis )MB-NM-3.

4. A microbial agent according to claim 3, characterized in that: The Bacillus Velez Bacillus velezensis )The live bacterial count of MB-NM-3 is 10 7 ~10 11 CFU / g or 10 7 ~10 11 CFU / mL.

5. Use of a Bacillus Velezii according to claim 1 or 2 or a microbial agent according to claim 3 or 4 in degrading lignite.

6. The use according to claim 5, characterized in that: When degrading the lignite, the lignite does not need to undergo any pretreatment.

7. Use of a Bacillus Velez subtilis according to claim 1 or 2 or a microbial agent according to claim 3 or 4 in resisting pathogenic fungi.

8. Use of a Bacillus Velez subtilis according to claim 1 or 2 or a microbial agent according to claim 3 or 4 in salt-alkali resistance.

9. Use of a Bacillus Velez subtilis according to claim 1 or 2 or a microbial agent according to claim 3 or 4 in producing extracellular polysaccharides and improving soil aggregate structure.

10. Use of a Bacillus Velezii according to claim 1 or 2 or a microbial agent according to claim 3 or 4 in degrading organic matter.

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