Mitsuaria mitsuensis ZKSW002, bacterial inoculant and application thereof

Abstract

The present application relates to a strain of Mitsuaria thiaminolyticus ZKSW002, a bacterial agent and application thereof, and belongs to the technical field of microorganisms. The Mitsuaria thiaminolyticus ZKSW002 is preserved in the China General Microbiological Culture Collection Center, with a preservation number of CGMCC No. 36075, a preservation date of September 25, 2025, and an address of the preservation agency of No. 3, Xili, Beichen West Road, Chaoyang District, Beijing. The present application also provides an application of the Mitsuaria thiaminolyticus ZKSW002 in inhibiting soil harmful bacteria, preventing and treating root-knot nematodes and promoting plant growth. The Mitsuaria thiaminolyticus ZKSW002 of the present application can promote crop growth, achieve reduced fertilizer and increased efficiency, control the occurrence of soil-borne fungal and bacterial diseases, and inhibit the growth of root-knot nematodes. The present application can reduce the use of chemical pesticides, reduce pesticide residues, and promote the sustainable development of agricultural economy.

Description

Technical Field

[0001] This invention relates to the field of microbial technology, specifically to a strain of Bacillus mifepristone ZKSW002, its inoculum, and its applications. Background Technology

[0002] Resource utilization of organic solid waste, cleaner production in the textile industry, and biological control and plant growth promotion technologies in agriculture are all current research hotspots in the fields of industrial upgrading and ecological protection. Among these, microorganisms, due to their diverse metabolic functions and environmental adaptability, have demonstrated significant advantages in the applications of these fields, becoming one of the core carriers for related technology research and development.

[0003] Bacillus mifepristonei (thiamine-degrading Bacillus) Aneurinibacillus migulanus As a Gram-positive bacterium belonging to the Bacillus family and the Bacillus genus, *Bacillus thiamine*, its cells are rod-shaped and can form elliptical spores. It is Gram-positive and its most significant biological characteristic is its ability to decompose thiamine. Currently, this strain has demonstrated clear application value in several industrial sectors: in the field of organic solid waste composting, it can secrete a key lignin-degrading enzyme system, effectively promoting the composting process and improving the efficiency of waste resource utilization; in the degumming process of hemp fibers in the textile industry, this strain can efficiently remove pectin, hemicellulose, and other non-cellulose gums from hemp fibers, and possesses the advantages of stable enzyme activity and minimal fiber damage, providing a feasible path for cleaner production in the textile industry.

[0004] However, current technologies for the application and development of *Bacillus mifepristone* still have significant limitations. Its applications are concentrated in composting and textile degumming, while research on its application in the highly demanded fields of biological control and plant growth promotion in agriculture is scarce. Its potential functional value in these areas has not yet been explored and utilized, resulting in the underutilization of the strain's application potential and limiting the expansion of agricultural biological control and plant growth promotion microbial resource banks. Therefore, it is necessary to conduct research on the untapped application value of *Bacillus mifepristone* to enrich its application scenarios and improve the comprehensive utilization efficiency of the strain. Summary of the Invention

[0005] To address the issue that Bacillus mifepristone has not yet been found to be used in existing biological pesticides, this invention provides a strain of Bacillus mifepristone ZKSW002, its inoculum, and its application, in order to solve the aforementioned problem.

[0006] In a first aspect, the present invention provides a strain of *Bacillus mifepristonei* ZKSW002, wherein *Bacillus mifepristonei* (… Aneurinibacillus migulanusZKSW002 is deposited at the China General Microbiological Culture Collection Center (CGMCC) with accession number CGMCC No. 36075, deposited on September 25, 2025. The address of the depository is No. 3, No. 1 Beichen West Road, Chaoyang District, Beijing.

[0007] Furthermore, the 16S rDNA sequence of the Bacillus mifepristone ZKSW002 is shown in SEQ ID NO.1.

[0008] Secondly, the present invention provides a bacterial agent containing Bacillus mifepristone ZKSW002, the bacterial agent comprising liquid bacterial agent and solid bacterial agent.

[0009] A method for preparing the above-mentioned bacterial agent, wherein the liquid bacterial agent is prepared by: inoculating *Bacillus mifepristonei* ZKSW002 into LB medium and culturing at 35°C and 180 rpm for 24 h to obtain a bacterial suspension containing *Bacillus mifepristonei* ZKSW002; adjusting the concentration of *Bacillus mifepristonei* ZKSW002 in the bacterial suspension to 2 × 10⁻⁶. 9 The liquid bacterial agent ZKSW002 of Bacillus mifepristone was prepared by using cfu / mL.

[0010] A method for preparing the above-mentioned bacterial agent, wherein the solid bacterial agent is prepared by adding 10% diatomaceous earth by volume to the liquid bacterial agent of Bacillus mikimotoi ZKSW002, and spray drying at 120°C to obtain the solid bacterial agent of Bacillus mikimotoi ZKSW002.

[0011] Preferably, the LB culture medium comprises the following components: 10 g / L tryptone, 5 g / L NaCl, 10 g / L yeast extract, sterile water, and pH=7.2.

[0012] Thirdly, the present invention provides the application of Bacillus mifepristonei ZKSW002 in nitrogen fixation, phosphorus solubilization and potassium solubilization.

[0013] Fourthly, this invention provides the application of Bacillus mifepristonei ZKSW002 in inhibiting Fusarium oxysporum cucumber-specific type, Rhizoctonia solani, Gramineae graminearum, Fusarium oxysporum cucumeris-specific type, and Powdery mildew of the Poaceae family.

[0014] Fifthly, the present invention provides the application of Bacillus mifepristonei ZKSW002 in the prevention and control of cucumber wilt disease.

[0015] Sixthly, the present invention provides the application of Bacillus mifepristonei ZKSW002 in promoting plant growth, wherein the plant is Chinese cabbage.

[0016] Furthermore, the application includes root irrigation treatment of plants using a liquid bacterial agent containing Bacillus mifepristone ZKSW002.

[0017] In a seventh aspect, the present invention provides the application of Bacillus mifepristonei ZKSW002 in inhibiting root-knot nematodes.

[0018] The beneficial effects of this invention are as follows:

[0019] The *Bacillus mifepristone* ZKSW002 provided in this invention is a superior strain with stable, diversified functions and outstanding efficacy. We are expanding its application to large-scale agricultural production and environmental remediation. The bacterial agent containing *Bacillus mifepristone* ZKSW002 is a broad-spectrum, safe, and effective microbial fungicide. It can promote crop growth, reduce fertilizer use and increase efficiency, and control soil-borne fungal and bacterial diseases (such as cucumber wilt) and agricultural pests (such as root-knot nematodes). This reduces the use of chemical pesticides, lowers pesticide residues, and promotes sustainable agricultural economic development. Attached Figure Description

[0020] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, for those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0021] Figure 1 This is a diagram illustrating the nitrogen fixation function of Bacillus mifepristone ZKSW002 in Example 1 of this invention.

[0022] Figure 2 This is a graph showing the phosphorus-solubilizing effect of Bacillus mifepristone ZKSW002 in Example 1 of this invention.

[0023] Figure 3 This is a diagram showing the potassium-solubilizing effect of Bacillus mifepristone ZKSW002 in Example 1 of this invention.

[0024] Figure 4 This is a growth diagram of Bacillus mifepristone ZKSW002 in NA medium in Example 1 of the present invention.

[0025] Figure 5 This is a Gram staining image of Bacillus mifepristone ZKSW002 in Example 1 of this invention.

[0026] Figure 6 This is a spore staining image of Bacillus mifepristone ZKSW002 in Example 1 of the present invention.

[0027] Figure 7This is a plate confrontation result diagram of Bacillus mitomyces ZKSW002 in Example 2 of the present invention.

[0028] Figure 8 This is a comparison chart of the disease conditions of cucumber seedlings in Example 4 of the present invention.

[0029] Figure 9 This is a comparison diagram of the growth promotion of Chinese cabbage in Example 4 of the present invention.

[0030] Figure 10 This is a comparison diagram of the degree of root knots in cucumber seedlings in Embodiment 5 of the present invention. Detailed Implementation

[0031] To enable those skilled in the art to better understand the technical solutions of this invention, the technical solutions of the embodiments of this invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this invention, and not all embodiments. Based on the embodiments of this invention, all other embodiments obtained by those skilled in the art without creative effort should fall within the scope of protection of this invention.

[0032] Example 1

[0033] Isolation, screening and identification of Bacillus mifepristone ZKSW002

[0034] (1) Sampling: On July 31, 2025, soil was collected from a rose planting base in Jinning District, Kunming City, Yunnan Province (102.5469°E, 24.5492°N) and stored in a resealable bag for later use.

[0035] (2) Separation: Take 5g of rhizosphere soil collected in step (1), add it to a conical flask containing 45mL of sterile pure water, bathe in a 100℃ water bath for 10 minutes, let it stand, take the upper layer solution and dilute it into samples with different concentration gradients, spread it on nutrient agar (NA) plate culture medium using a spreader, and incubate it upside down at 35℃ for 24h.

[0036] (3) Purification: Select single colonies with different morphologies, and purify each single colony by streaking on NA plates three times. Select strains according to different colony morphologies and determine their numbers. Preserve them in test tube slant and store them in a 4℃ refrigerator as test bacteria for later experiments. At the same time, place them in 50% sterile glycerol tubes and store them at -20℃ for later use.

[0037] (4) Identification of nitrogen fixation, phosphorus solubilization, and potassium solubilization functions

[0038] Different isolated and purified bacterial strains were inoculated into LB medium and cultured at 35°C and 180 rpm for 20 h on a shaker. The bacterial suspension was then diluted to 10⁻⁶. -6For gradient assays, 100 μL of the diluted solution was spread onto identification medium plates. Nitrogen fixation function was assessed using Assumption agar plates, phosphate solubilization function using inorganic phosphorus bacteria agar plates, and potassium solubilization function using Alexandrov agar plates. If colonies grow normally on the plate, it indicates that the strain possesses the corresponding function selected for that plate. See the nitrogen fixation function effect diagram for strain ZKSW002 for details. Figure 1 For detailed images showing the phosphorus solubilization effect, please see [link / image]. Figure 2 For a detailed diagram showing the potassium-relieving effect, please see [link / image]. Figure 3 .according to Figures 1-3 It can be determined that strain ZKSW002 has the functions of nitrogen fixation, phosphorus solubilization, and potassium solubilization.

[0039] The components and contents of the above three identification culture medium plates are as follows:

[0040] Assumption medium: potassium dihydrogen phosphate 0.2 g / L, magnesium sulfate 0.2 g / L, sodium chloride 0.2 g / L, calcium carbonate 5.0 g / L, mannitol 10.0 g / L, calcium sulfate 0.1 g / L, agar 15.0 g / L, pH=7.0±0.1.

[0041] Inorganic phosphorus bacteria culture medium: sucrose 5.0 g / L, magnesium sulfate 0.5 g / L, disodium hydrogen phosphate 2.0 g / L, ferric chloride 0.005 g / L, calcium carbonate 0.1 g / L, soil minerals 1.0 g / L, agar 18.0 g / L, pH=7.2±0.2.

[0042] Alexandrov medium: sucrose 5.0 g / L, magnesium sulfate 0.5 g / L, disodium hydrogen phosphate 2.0 g / L, ferric chloride 0.005 g / L, calcium carbonate 0.1 g / L, soil minerals 1.0 g / L, agar 18.0 g / L, pH=7.2±0.2.

[0043] (5) Morphological identification

[0044] Strain strain ZKSW002 was inoculated into LB medium and cultured at 35°C and 180 rpm for 24 h. Diluted to 10⁻⁶. -7 After gradient inoculation, 100 μL was spread onto NA plates and incubated at 35°C for 48 h. The color, shape, and size of single colonies were continuously observed. Figure 4 As shown, strain ZKSW002 grows well on NA medium, with punctate colonies that are white and have spiky edges.

[0045] (6) Gram staining was performed, and the results of optical microscopy showed that the bacteria were rod-shaped and had spores. See details. Figure 5 Then, spore staining was performed, and the results showed that the spores were oval-shaped. See details... Figure 6 .

[0046] (7) Physiological and biochemical identification

[0047] Physiological and biochemical identification of strain ZKSW002 was performed, and the detection items and results are shown in Table 1.

[0048] Table 1 - Physiological and biochemical identification results of strain ZKSW002

[0049]

[0050] (8) Molecular identification

[0051] Single colonies of strain ZKSW002 were streaked onto NA plates and incubated at 35°C for 12 hours. The incubated NA plates were then sent to Sangon Biotech (Shanghai) Co., Ltd. for strain identification. The 16S rDNA sequence is shown in SEQ ID NO.1, with a length of 1475 bp.

[0052] The sequences obtained from sequencing were submitted to GenBank for homology comparison. Strain ZKSW002 was compared with... Aneurinibacillus migulanus strain RD With a homology of 99.93%, the strain was preliminarily identified as *Bacillus mifepristoneii*. Aneurinibacillus migulanus Bacillus mifepristone ZKSW002 is deposited at the China General Microbiological Culture Collection Center (CGMCC) with accession number CGMCC No. 36075, deposited on September 25, 2025. The address of the depository is No. 3, No. 1 Beichen West Road, Chaoyang District, Beijing.

[0053] Example 2

[0054] Flat-plate standoff test

[0055] A plate confrontation test was conducted on *Bacillus mifepristone* ZKSW002, with pathogens used in this test including the cucumber wilt pathogen (*Fusarium oxysporum* cucumber-specific strain). Fusarium oxysporum f.sp. cucumerinum Potato black scurvy pathogen (Rhizoctonia solani) Rhizoctonia solan i) Wheat take-all pathogen (Gracilaria graminearum) Gaeumannomyces graminis The pathogen causing banana wilt (Fusarium oxysporum, Cuban variant) Fusarium oxysporumf.sp.cubense ), the pathogen of wheat powdery mildew (Phyllostachys bryony) Blumeria graminis ).

[0056] The specific method is as follows:

[0057] Mycelial cakes of cucumber wilt pathogens, potato black scurf pathogens, wheat take-all pathogens, banana wilt pathogens, and wheat powdery mildew pathogens (6 mm in diameter) were inoculated in the center of PDA plates. 8 μL of the culture medium of the tested strain was pipetted onto each plate, 2 cm away from the pathogen, and incubated at room temperature for 7–10 days. The antibacterial activity in each plate was observed to determine whether the tested strains had the corresponding antibacterial effect. The plate confrontation test results for *Bacillus mitomyces* ZKSW002 are as follows: Figure 7 As shown, Bacillus mifepristone ZKSW002 exhibits significant inhibitory effects on the pathogens of cucumber wilt, potato black scurf, wheat take-all, banana wilt, and wheat powdery mildew.

[0058] Example 3

[0059] Preparation of Bacillus mifepristone ZKSW002 bacterial agent

[0060] Liquid bacterial inoculum: Bacillus thiophanate-releasing (Bt) ZKSW002 was activated on NA agar plates. One loopful of the activated Bt. releasing (Bt) ZKSW002 was inoculated onto LB agar and cultured at 35°C and 180 rpm for 24 h to obtain the Bt. releasing (Bt) ZKSW002 bacterial suspension. The LB agar composition was as follows: tryptone 10 g / L, NaCl 5 g / L, yeast extract 10 g / L, sterile water, pH 7.2. The bacterial concentration of the Bt. releasing (Bt) ZKSW002 suspension was then adjusted to 2 × 10⁻⁶. 9 The liquid bacterial agent ZKSW002 of Bacillus mifepristone was prepared by using cfu / mL.

[0061] Solid bacterial agent: Add 10% diatomaceous earth to the liquid bacterial agent of Bacillus thiamine mifepristone ZKSW002 by volume ratio, and spray dry at 120℃ to obtain the solid bacterial agent of Bacillus thiamine mifepristone ZKSW002.

[0062] Example 4

[0063] Biological control capability experiment of Bacillus mifepristone ZKSW002

[0064] Ability to control cucumber wilt

[0065] To control cucumber wilt, a biocontrol experiment was conducted using the liquid inoculum of *Bacillus mirabilis* ZKSW002 prepared in Example 3. Two parallel treatments were established: the *Bacillus mirabilis* ZKSW002 group and the control group (CK), with 10 replicates in each group. The *Bacillus mirabilis* ZKSW002 group was treated with the liquid inoculum prepared in Example 3, while the control group received no biocontrol product. The specific application method was as follows: the inoculum was diluted 200 times (bacterial concentration 1.0 × 10⁻⁶). 7 100 mL of the pretreatment solution (cfu / mL) was applied to the roots of 4-week-old cucumber seedlings (the control group was treated with plain water). After 24 hours of pretreatment, the seedlings were inoculated with a fungus containing cucumber wilt pathogen (Fusarium oxysporum cucumber-specific strain) with a turbidity of 1.0 MCF using the root irrigation method. Disease indices were continuously recorded and phenotypes were observed. Specific results are shown in Table 2, and disease images of the cucumber seedlings are available in [link to table]. Figure 8 .

[0066] Disease severity levels: Level 0, no symptoms; Level 1, cotyledons yellowing but not wilting; Level 2, cotyledons wilting; Level 3, cotyledons and true leaves wilting or plant stunting; Level 4, death.

[0067] Disease index = ∑(number of diseased plants at each level × representative value at each level) / (total number of plants surveyed × highest representative value) × 100.

[0068] Prevention and control effect (%) = [(control disease index - treatment disease index) / control disease index] × 100.

[0069] Table 2 - Control efficacy of Bacillus mifepristone ZKSW002 against cucumber wilt disease

[0070]

[0071] like Figure 8 As shown in Table 2, almost all plants in the control group exhibited symptoms of cucumber wilt, with significant stunting, yellowing and wilting of most leaves, and even complete death. In the Bacillus mitomycin ZKSW002 group, more than half of the plants showed no symptoms and grew well, while the remaining plants showed yellowing of cotyledons. Bacillus mitomycin ZKSW002 has a significant control effect on cucumber wilt.

[0072] Example 5

[0073] The growth-promoting effect of Bacillus mifepristone ZKSW002 on Chinese cabbage

[0074] Using Chinese cabbage as the experimental subject, a growth-promoting experiment was conducted using Bacillus thiamine mifepristone ZKSW002. Two parallel treatments were set up: the Bacillus thiamine mifepristone ZKSW002 group and the control group (CK), with 10 replicates in each group. A 100-fold dilution of the liquid Bacillus thiamine mifepristone ZKSW002 was prepared, and 100 mL of the dilution was used for root irrigation. The control group received 100 mL of water without any growth-promoting products. Chinese cabbage was transplanted after the third true leaf unfolded. The first root irrigation treatment was performed the day after transplanting, followed by root irrigation every 7 days for a total of 3 treatments. Seven days after the third root irrigation treatment, the plant height was measured with a ruler, the stem diameter was measured with calipers, and the fresh weight of the above-ground parts was measured using a balance. The results are shown in Table 3. Figure 9 As shown.

[0075] Table 3 - Growth-promoting effects of Bacillus mifepristone ZKSW002 on Chinese cabbage

[0076]

[0077] The experimental results showed that, compared with the blank control group, the plant height of plants treated with Bacillus thiamine mifepristone ZKSW002 bacterial solution did not change significantly, but the stem diameter increased by 38.8% and the fresh weight increased by 36.5%. This indicates that Bacillus thiamine mifepristone ZKSW002 has good growth-promoting properties for Chinese cabbage.

[0078] Example 6

[0079] The ability of Bacillus mifepristone ZKSW002 to inhibit root-knot nematodes (in vitro method)

[0080] Preparation of fermentation broth for *Bacillus thiamine mifepristone* ZKSW002: *Bacillus thiamine mifepristone* ZKSW002 was activated and inoculated at a 5% inoculum volume into a 250 mL shake flask containing 100 mL of LB liquid medium. The broth was incubated at 37 °C and 180 rpm for 36 h. After incubation, the broth was centrifuged at 4 °C and 12000 rpm for 10 min. The supernatant was the fermentation broth of *Bacillus thiamine mifepristone* ZKSW002. It was stored at 4 °C for later use.

[0081] 500 μL of the above-mentioned Bacillus mifepristone fermentation broth ZKSW002 was directly added to a sterile 24-well plate, along with 500 μL of root-knot nematode J2 suspension (approximately 100 nematodes). An equal volume of sterile water was used as a control. The plates were incubated at 28°C. After 24 hours, the survival of the root-knot nematodes J2 was observed under a stereomicroscope. The criterion for death was that the root-knot nematodes exhibited a rigid, immobile state. If 2-3 drops of 1 mol / L sodium hydroxide solution were added, the nematodes remained rigid and immobile; otherwise, they were considered dead. The number of dead nematodes was counted against the total number of nematodes, and the mortality rate and corrected mortality rate were calculated. Each treatment was replicated three times, and the experiment was repeated twice. The experimental results are shown in Table 4.

[0082] Mortality rate (%) = Number of root-knot nematode deaths / Total number of root-knot nematodes × 100%.

[0083] Corrected mortality rate (%) = (treatment mortality rate - control mortality rate) / (1 - control mortality rate) × 100%.

[0084] Table 4 - Inhibition results of Bacillus mifepristone ZKSW002 on root-knot nematodes

[0085]

[0086] The ability of Bacillus mifepristone ZKSW002 to inhibit root-knot nematodes (in vitro method).

[0087] Experimental Method: Germinated cucumber seedlings were planted in test tubes pre-filled with 10 ml of fine sand. Each test tube in the treatment group was treated with 3 mL of a 20-fold diluted *Bacillus mitomyces* ZKSW002 liquid inoculum (prepared in Example 3), while each test tube in the control group was treated with 3 mL of sterile water. Each treatment was replicated five times. The next day, root-knot nematode eggs (300 eggs / tube) were added to each test tube. After 14 days of incubation, the number of root knots was observed and graded. Test results are as follows: Figure 10 As shown.

[0088] Root knot classification criteria:

[0089] Grade 0: No root knots on the root system, the root system appears normal, and there are no visible root knot symptoms.

[0090] Grade 1: There are a few root knots; generally there are 1 to 2 small root knots on the root system, and the diameter of the root knot is usually less than 2 mm, which has little impact on the overall morphology and function of the root system.

[0091] Level 2: There are multiple root knots on the root system, but the distribution of root knots is relatively sparse. The number of root knots is generally 3 to 5, and the diameter of the root knots is between 2 and 4 mm. The root system begins to show some morphological changes, such as local root swelling, but it does not affect the normal growth and absorption function of most roots.

[0092] Grade 3: The root system has a large number of root knots, which are relatively dense. The number of root knots is generally 6 to 10, and the diameter of the root knots is 4 to 6 mm. The root system morphology is obviously changed, and many roots show swelling, twisting and other phenomena, which have a certain impact on the absorption and transport functions of the root system. The plant may show mild symptoms of poor growth.

[0093] Level 4: Numerous root knots appear on the root system, almost covering the entire root system. The number of root knots exceeds 10, and the diameter of the root knots is greater than 6mm. The root system is severely deformed, appearing as nodules or chicken claws. The root system function is severely impaired, and the plant growth is significantly hindered. Symptoms such as yellowing leaves, stunting, and wilting appear, which have a significant impact on yield and quality.

[0094] Depend on Figure 10 The results showed that no root knots were formed in the roots treated with the liquid inoculum of *Bacillus mikimotoi* ZKSW002. In contrast, the control group showed root knot severity level 3. This indicates that *Bacillus mikimotoi* ZKSW002 of this invention has good root-knot nematode killing ability under in vitro conditions, and can inhibit nematode activity and prevent nematode invasion of plant roots to form root knots under indoor in vivo conditions. Therefore, this strain has good application potential for root-knot nematode control.

[0095] Although the present invention has been described in detail with reference to the accompanying drawings and preferred embodiments, the present invention is not limited thereto. Various equivalent modifications or substitutions can be made to the embodiments of the present invention by those skilled in the art without departing from the spirit and essence of the invention, and such modifications or substitutions should all be within the scope of the present invention. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in the present invention should also be covered within the protection scope of the present invention.

Claims

1. A strain of Mitsuokella jalaludinii (M. jalaludinii) ZKSW002, characterized in that, Aneurinibacillus migulanus ) ZKSW002, characterized in that, The Bacillus mitomycin ZKSW002 is deposited at the China General Microbiological Culture Collection Center (CGMCC) with accession number CGMCC No. 36075, deposited on September 25, 2025. The address of the depository is No. 3, No. 1 Beichen West Road, Chaoyang District, Beijing.

2. A microbial agent containing Bacillus thiaminolyticus ZKSW002 as claimed in claim 1, characterized in that, The microbial agents include liquid microbial agents and solid microbial agents.

3. The bacterial agent of claim 2, wherein The preparation method of the liquid bacterial agent is as follows: Bacillus mifepristone ZKSW002 is inoculated into LB medium and cultured at 35℃ and 180 rpm for 24 h to obtain a bacterial suspension containing Bacillus mifepristone ZKSW002; the concentration of Bacillus mifepristone ZKSW002 in the bacterial suspension is adjusted to 2 × 10⁻⁶. 9 The liquid bacterial agent ZKSW002 of Bacillus mifepristone was prepared by using cfu / mL.

4. The bacterial agent of claim 2, wherein The solid bacterial agent is prepared by adding 10% diatomaceous earth by volume to the liquid bacterial agent of Bacillus mirabilis ZKSW002, and spray drying at 120°C to obtain the solid bacterial agent of Bacillus mirabilis ZKSW002.

5. The application of Bacillus mifepristone ZKSW002 as described in claim 1 in nitrogen fixation, phosphorus solubilization and potassium solubilization.

6. The application of Bacillus mifepristonei ZKSW002 as described in claim 1 in inhibiting Fusarium oxysporum cucumber-specific type, Rhizoctonia solani, Gramineae graminearum, Fusarium oxysporum cucumeris-specific type, and Powdery mildew of the Poaceae family.

7. The application of Bacillus mifepristone ZKSW002 as described in claim 1 in the control of cucumber wilt disease.

8. The application of Bacillus mifepristone ZKSW002 as described in claim 1 in promoting plant growth, characterized in that, The plant in question is bok choy.

9. Use according to claim 8, wherein the compound is ###0002### The application includes root irrigation of plants using a liquid inoculum containing Bacillus mifepristone ZKSW002.

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