Intermediate Brucella CZJ2 and application thereof

Abstract

The invention discloses Brucella intermedius CZJ2 and application thereof, and belongs to the technical field of microorganisms. According to the invention, the Brucella intermedia CZJ2 is obtained through screening and identification, and the preservation number of the Brucella intermedia CZJ2 is CGMCC (China General Microbiological Culture Collection Center) No.36252. Through verification, the strain CZJ2 has the characteristics of fixing nitrogen, dissolving phosphorus, dissolving silicate and serving as a siderophore producing strain, can promote decomposition and conversion of nutrient substances (nitrogen, phosphorus, silicate and iron) in soil, and is beneficial to promoting absorption of plants to the nutrient substances; the strain CZJ2 is applied to the field of wild barley, the influence of the strain CZJ2 on the growth capacity of the wild barley is verified by simulating a saline-alkali planting system, and the result shows that the strain CZJ2 can promote the growth of the wild barley in a saline-alkali environment or a non-saline-alkali environment, so that the strain CZJ2 has the effect of promoting the growth of plants, can relieve saline-alkali stress and can promote the growth of the wild barley under the saline-alkali stress.

Description

Technical Field

[0001] This invention relates to the field of microbial technology, and in particular to an intermediate Brucella CZJ2 and its applications. Background Technology

[0002] Soil salinity in agricultural soils refers to the high concentration of soluble salts in soil moisture. These soluble salts create high osmotic pressure, which limits plant water absorption and the balanced absorption of essential nutrients by roots, thus affecting plant growth. The formation of saline-alkali land is the result of multiple factors, including long-term over-cultivation leading to soil structure damage, excessive fertilization causing salt accumulation, and drought causing groundwater salts to rise to the surface with evaporation. The most direct impact of soil salinization is reduced grain yields. Annual crop failures due to salinization pose a serious threat to my country's food security. Improving and rationally utilizing saline-alkali land can not only transform low-yield, stagnant soil into arable land but also directly increase the cultivated land area, playing an irreplaceable role in ensuring stable food supply and maintaining ecological security.

[0003] Beneficial microbial communities in microbial inoculants, through a series of decomposition and synthesis processes such as nitrogen fixation and phosphorus solubilization, can transform soil substances into various nutrients, improving soil fertility and promoting plant growth. Beneficial microorganisms can also secrete various antibiotics and other antibacterial substances, inhibiting the growth and reproduction of pathogens, inducing systemic disease resistance in plants, reducing disease occurrence, and enhancing plant stress resistance. In recent years, the application of microbial technology in saline-alkali soil remediation has received increasing attention and strengthening, mainly focusing on research into enhancing plant salt and alkali tolerance through microorganisms. Existing studies have found that salt-tolerant microorganisms can improve the rhizosphere environment of plants, reduce the inhibitory effect of salt on crop growth, and achieve the goal of improving saline-alkali soil. Therefore, microbial activity can, to a certain extent, improve the survival rate and retention rate of vegetation in saline-alkali soils, playing an important role in the long-term improvement of saline-alkali soils, restoring soil physicochemical properties, and reconstructing the ecological environment of saline-alkali soils. Summary of the Invention

[0004] The purpose of this invention is to provide an intermediate Brucella CZJ2 strain and its application to solve the problems existing in the prior art. This invention verifies that strain CZJ2 has the effect of promoting plant growth and can also alleviate salt and alkali stress and promote the growth of wild barley under salt and alkali stress.

[0005] To achieve the above objectives, the present invention provides the following solution:

[0006] This invention provides an intermedia brucellosis strain CZJ2, which was deposited on October 20, 2025, at the China General Microbiological Culture Collection Center (CGMCC) with accession number CGMCC No. 36252, located at Institute of Microbiology, Chinese Academy of Sciences, No. 3, Beichen West Road, Chaoyang District, Beijing.

[0007] The present invention also provides a microbial inoculant containing the aforementioned Brucella intermediate CZJ2 or its bacterial suspension.

[0008] The present invention also provides the application of the aforementioned Brucella intermediate CZJ2 or the aforementioned microbial agent in nitrogen fixation, phosphorus solubilization, phosphorus solubilization, silicate solubilization and / or siderogenic carriers.

[0009] The present invention also provides the application of the aforementioned Brucella intermediate CZJ2 or the aforementioned microbial agent in promoting plant growth.

[0010] The present invention also provides the use of the aforementioned Brucella intermediate CZJ2 or the aforementioned microbial agent in the preparation of products that promote plant growth.

[0011] Optionally, the plant includes wild barley.

[0012] The present invention also provides a method for promoting plant growth, comprising the step of treating the plant with the aforementioned Brucella intermedia CZJ2 or a suspension thereof.

[0013] Optionally, the step of inoculating the soil of the plant with a bacterial suspension of the intermediate Brucella CZJ2 is included.

[0014] Optionally, the OD of the bacterial suspension 600 It is 0.6-0.8.

[0015] Optionally, the plant includes wild barley.

[0016] The present invention discloses the following technical effects:

[0017] This invention obtained a strain of Brucella intermedia, CZJ2, through screening and identification, with the preservation number CGMCC No. 36252. Verification showed that strain CZJ2 possesses nitrogen-fixing, phosphorus-solubilizing, phosphorus-dissolving, silicate-solubilizing, and iron-producing characteristics, promoting the decomposition and transformation of nutrients (nitrogen, phosphorus, silicates, and iron) in the soil, which is beneficial for plant nutrient absorption. The effect of strain CZJ2 on the growth of wild barley was verified through a simulated saline-alkali planting system. The results showed that strain CZJ2 promoted the growth of wild barley in both saline-alkali and non-saline-alkali environments, indicating that strain CZJ2 has a plant growth-promoting effect and can also alleviate saline-alkali stress, promoting the growth of wild barley under saline-alkali stress. Attached Figure Description

[0018] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0019] Figure 1 This is a colony morphology diagram of strain CZJ2;

[0020] Figure 2 Phylogenetic tree of strain CZJ2;

[0021] Figure 3 The growth curves of strain CZJ2 at different salt concentrations are shown.

[0022] Figure 4 Plate dissolution zone for phosphorus solubilization of strain CZJ2;

[0023] Figure 5 Plate dissolution zone for phosphate solubilization of strain CZJ2;

[0024] Figure 6 The plate dissolution zone for silicate solubilization of strain CZJ2;

[0025] Figure 7 The plate dissolution zone of strain CZJ2 as an iron-producing carrier;

[0026] Figure 8 The effects of strain CZJ2 on the growth of wild barley under saline-alkali or non-saline-alkali conditions;

[0027] Figure 9 for Figure 8 A statistical chart showing the plant height (A), root length (B), fresh weight (C), and dry weight (D) of each group of wild barley. Detailed Implementation

[0028] Various exemplary embodiments of the present invention will now be described in detail. This detailed description should not be considered as a limitation of the present invention, but rather as a more detailed description of certain aspects, features, and embodiments of the present invention.

[0029] It should be understood that the terminology used in this invention is merely for describing particular embodiments and is not intended to limit the invention. Furthermore, with respect to numerical ranges in this invention, it should be understood that each intermediate value between the upper and lower limits of the range is also specifically disclosed. Any stated value or intermediate value within a stated range, as well as each smaller range between any other stated value or intermediate value within said range, is also included in this invention. The upper and lower limits of these smaller ranges may be independently included or excluded from the range.

[0030] Unless otherwise stated, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art. While only preferred methods and materials have been described herein, any methods and materials similar or equivalent to those described herein may be used in the implementation or testing of this invention. All references to this specification are incorporated by way of citation to disclose and describe methods and / or materials associated with those references. In the event of any conflict with any incorporated reference, the content of this specification shall prevail.

[0031] Various modifications and variations can be made to the specific embodiments described in this specification without departing from the scope or spirit of the invention, as will be apparent to those skilled in the art. Other embodiments derived from this specification will also be apparent to those skilled in the art. This specification and embodiments are merely exemplary.

[0032] The terms “include,” “including,” “have,” “contain,” etc., used in this article are all open-ended terms, meaning that they include but are not limited to.

[0033] LB medium: 10 g / L tryptone, 5 g / L yeast extract, 10 g / L sodium chloride, 18 g / L agar (solid), pH adjusted to 7.0-7.2.

[0034] LB liquid medium: 10 g / L tryptone, 5 g / L yeast extract, 10 g / L sodium chloride, pH adjusted to 7.

[0035] Nitrogen-fixing medium (nitrogen-free medium): mannitol 10 g / L, CaCO3 5 g / L, KH2PO4 0.2 g / L, MgSO4·7H2O 0.2 g / L, NaCl 0.2 g / L, CaSO4·2H2O 0.2 g / L, agar 20 g / L, pH adjusted to 7.0-7.2.

[0036] Mongkina Inorganic Phosphorus Solid Culture Medium: Glucose 10 g / L, yeast extract 0.5 g / L, (NH4)2SO4 0.5 g / L, MnSO4·7H2O 0.3 g / L, MnSO4·4H2O 0.03 g / L, KCl 0.3 g / L, FeSO4·7H2O 0.03 g / L, NaCl 0.3 g / L, Ca3(PO4)2 10 g / L, agar 15 g / L, pH adjusted to 7.0-7.5.

[0037] Mongkina organophosphorus solid culture: glucose 10 g / L, yeast extract powder 0.4 g / L, (NH4)2SO4 0.5 g / L, MnSO4·4H2O 0.03 g / L, KCl 0.3 g / L, FeSO4·7H2O 0.03 g / L, NaCl 0.3 g / L, CaCO3 5 g / L, egg yolk lecithin 0.2 g / L, agar 20 g / L, pH adjusted to 7.0.

[0038] Silicate bacteria culture medium: sucrose 5 g / L, MgSO4 0.5 g / L, CaCO3 0.1 g / L, Na2HPO4 2 g / L, FeCl3 0.005 g / L, glass powder 1.0 g / L, agar 15.0 g / L, pH adjusted to 7.0-7.2.

[0039] CAS detection medium: Chromium azurite S (CAS) 60.5 mg / L, cetyltrimethylammonium bromide 72.9 mg / L, FeCl3·6H2O 2.645 mg / L, NaH2PO4·2H2O 295.25 mg / L, Na2HPO4·12H2O 1213.5 mg / L, NH4Cl 125.0 mg / L, KH2PO4 37.5 mg / L, NaCl 62.5 mg / L, agar 9000.0 mg / L, pH adjusted to 6.7-6.9.

[0040] Saline-alkali culture medium: 10 g / L tryptone, 5 g / L yeast extract and 10 g / L sodium chloride were added to prepare saline-alkali culture media with mass concentrations of 0 mmol / L, 200 mmol / L, 400 mmol / L, 600 mmol / L and 800 mmol / L respectively, and the pH was adjusted to 7.

[0041] Example 1: Isolation and Identification of Growth-Promoting Bacterial Strains

[0042] 1. Isolation of growth-promoting bacterial strains

[0043] 1.1 Isolation of growth-promoting bacterial strains

[0044] Sample collection: Soil samples were collected from the saline-alkali land in Linze, Hexi Corridor. The soil collection adopted the five-point sampling method. Five sampling points were determined in the selected area. Soil samples of different degrees of salinity and alkali were collected from 10-20 cm deep. Equal amounts of soil were collected from each point, mixed, and then placed in sterile bags and sealed. The collection number, collection location, date and other key information were marked. The samples were brought back to the laboratory and stored at 4℃.

[0045] 1.2 Sample enrichment

[0046] Soil sample preparation: Soil samples were sieved through a 20-mesh sieve (approximately 1 mm in diameter). 10 g of the sample was weighed and placed in an Erlenmeyer flask containing 90 mL of sterile aqueous solution (containing 10-15 sterile glass beads). The flask was shaken at 28°C and 150 rpm for 2-3 hours, then allowed to stand for 10 minutes to obtain a 10-fold diluted soil suspension, recorded as 10. -1 Diluent. Use a pipette to take 1 mL of 10... -1 Add the diluent to a test tube containing 9 mL of sterile water, mix well by pipetting, and dilute to a 10:1 ratio. -2 Diluent, then dilute in the same manner to prepare 10. -3 10 -4 10 -5 10 -6 10 -7 Prepare a series of gradient dilutions; take 0.1 mL of each gradient dilution and spread it evenly on LB agar plates, repeating each concentration in 3 plates, and incubate the plates upside down in a 28°C incubator for 2-3 days.

[0047] 1.3 Strain isolation and screening

[0048] Select plates with suitable colony density (30-300 / plate), pick single colonies of different types from the above LB agar plates and streak them onto LB agar plates for isolation, incubate at 28℃ for 2-3 days, pick single cells again for streaking, and repeat the single cell streaking 2-3 times to obtain single cell pure cultures of each strain; pick single cells of each strain and inoculate them into LB liquid medium, incubate at 28℃ and 150 rpm for 12-24 h with shaking, and screen to obtain strains that show obvious growth in the medium for strain purification and preservation.

[0049] 1.4 Strain purification and preservation

[0050] The pure bacterial culture was cryopreserved in 30% glycerol at low temperature. The culture was named CZJ2.

[0051] 2. Isolation of growth-promoting bacterial strains

[0052] 2.1 Morphological identification

[0053] The purified strain CZJ2 was selected and cultured on LB agar using the streak plating method at 28°C for 2 days. Colony morphology was then observed; the colony morphology of the growth-promoting bacteria was as follows. Figure 1 As shown, the colonies are round with irregular edges, opaque, raised in the middle, smooth, bright, and moist.

[0054] 2.2 Molecular biological identification

[0055] The isolated and purified strain CZJ2 was subjected to molecular biological identification. This was achieved through DNA extraction, PCR amplification, and 16S rRNA gene sequencing.

[0056] Forward primer 27F: 5'-AGAGTTTGATCCTGGCTCAG-3' (SEQ ID NO.1);

[0057] Reverse primer 1492R: 5'-TACGGCTACCTTACGACTT-3' (SEQ ID NO.2).

[0058] The PCR product of the amplified 16S rRNA was sent to Sangon Biotech (Shanghai) Co., Ltd. for sequencing.

[0059] By performing nucleic acid sequence homology alignment (Blastn) in the GenBank database on NCBI, the strain was preliminarily identified as Brucella sp.

[0060] Further phylogenetic tree construction was performed on the sequencing results, and the results are as follows: Figure 2 As shown, strain CZJ2 is evolutionarily closely related to the known Brucella intermedia.

[0061] Therefore, the above-mentioned strain was identified as Brucella intermedia and named CZJ2. This strain was deposited on October 20, 2025, at the China General Microbiological Culture Collection Center (CGMCC) with accession number CGMCC No. 36252. The deposit address is Institute of Microbiology, Chinese Academy of Sciences, No. 3, No. 1 Beichen West Road, Chaoyang District, Beijing.

[0062] Example 2: Salt tolerance identification of growth-promoting bacterial strain CZJ2

[0063] Preparation of CZJ2 seed culture: Single colonies of strain CZJ2 were picked and inoculated into LB liquid medium test tubes and cultured at 28℃ and 180rpm for 24h to prepare CZJ2 seed culture.

[0064] Saline-alkali culture media with concentrations of 0 mmol / L, 200 mmol / L, 400 mmol / L, 600 mmol / L, and 800 mmol / L were prepared. CZJ2 seed culture was inoculated at a 3% inoculum and cultured for 40 h. The growth curves of strain CZJ2 at different salt concentrations were then determined. The growth curves are shown below. Figure 3 As shown.

[0065] Depend on Figure 3 It can be seen that the time required for CZJ2 to enter the logarithmic phase increases with increasing salt concentration in the culture medium; the strain exhibits the best growth performance at a salt concentration of 600 mmol / L, entering the logarithmic phase after 2 hours of culture and reaching its peak after 4 hours; the strain can tolerate a salt concentration of 800 mmol / L, and at this concentration, the bacterial concentration OD200 reaches a stationary phase. 600 With a concentration exceeding 0.2, it can be concluded that strain CZJ2 can grow normally and maintain stable viability and tolerance in culture media with salt concentrations not exceeding 600 mmol / L. This indicates that CZJ2 can grow and reproduce normally and maintain viability in high-salt culture media. This demonstrates that CZJ2 can adapt to high-salt, high-osmotic-pressure environments, has a wider range of applications, and can be used for the biological treatment of high-salt wastewater and the improvement of saline-alkali soils.

[0066] Example 3: Identification of the nitrogen fixation, phosphorus solubilization, phosphorus lysis, silicate solubilization, and siderophore production capabilities of growth-promoting bacterial strain CZJ2

[0067] 1. Nitrogen fixation capacity assessment

[0068] Nitrogen-free medium test: Pick a small number of single colonies of strain CZJ2, streak them on a plate of nitrogen-free medium, and observe whether the strain can grow and form colonies on nitrogen-free medium.

[0069] Nitrogenase activity assay (acetylene reduction method): Seed culture of strain CZJ2 was inoculated into LB liquid medium at a 3% inoculum and cultured at 28℃ and 180 rpm for 24 h with shaking. The culture was then transferred to centrifuge tubes and centrifuged at 4℃ and 8000 rpm for 10 min to collect the bacterial cells. The cells were washed 2-3 times with physiological saline and resuspended to adjust the OD concentration. 600 =1.0, and a bacterial suspension was prepared; 1 mL of the bacterial suspension was added to a centrifuge tube containing 9 mL of nitrogen-free medium and shaken for 1 h, and then sent to Shanghai Zhuocai Biotechnology Co., Ltd. to detect the nitrogenase activity of CZJ2. The result showed that the nitrogenase activity of CZJ2 was 68.9079 nmol / (mL×h).

[0070] Therefore, CZJ2 has high nitrogenase activity.

[0071] 2. Identification of phosphorus solubility (inorganic phosphorus)

[0072] Take 5 μL of the seed culture of strain L238 and spot it onto the center of a Monkina inorganic phosphorus medium plate. Repeat the process three times and incubate at 28℃ for 3-5 days. Observe whether a clear zone is formed around the colony.

[0073] The results are as follows Figure 4 As shown, this strain produces a clear phosphorus-solubilizing zone on the phosphorus-solubilizing medium, indicating that the strain has a significant effect on solubilizing inorganic phosphorus.

[0074] 3. Phosphorus solubility (organic phosphorus) assessment

[0075] Take 5 μL of the seed culture of strain CZJ2 and spot it onto the center of a Monkina organophosphate medium plate. Repeat the process three times and incubate at 28℃ for 3-5 days. Observe whether a clear zone is formed around the colony.

[0076] The results are as follows Figure 5 As shown, CZJ2 produces a clear phosphorus-solubilizing transparent zone on the phosphorus-solubilizing medium, indicating that CZJ2 has a significant effect on solubilizing organic phosphorus.

[0077] 4. Silicate solubility assessment

[0078] Take 5 μL of the seed culture of strain CZJ2 and spot it onto the center of a silicate bacteria culture medium plate. Repeat the process 3 times and incubate at 28℃ for 3-5 days. Observe whether oil droplets are produced around the colonies.

[0079] The results are as follows Figure 6 As shown, CZJ2 can produce oil droplets on silicate bacteria culture medium, indicating that CZJ2 has obvious silicate solubilizing properties.

[0080] 5. Assessment of Iron Production Capacity

[0081] Take 5 μL of the seed culture of strain CZJ2 and spot it onto the center of a CAS detection medium plate. Repeat the process three times and incubate at 28℃ for 3-5 days. Observe whether an orange-yellow halo appears around the colony.

[0082] The results are as follows Figure 7 As shown, CZJ2 can produce a yellow halo on the siderogenic detection medium, and the ratio of the diameter of the bacterial ring to the diameter of the colony is 4.95 cm, indicating that CZJ2 has the characteristics of siderogenic production.

[0083] In summary, the CZJ2 strain of the present invention possesses the characteristics of nitrogen fixation, phosphorus solubilization, phosphorus dissolution, silicate solubilization, and acting as a strain that produces iron carriers. It can promote the decomposition and transformation of nutrients (nitrogen, phosphorus, silicates, and iron) in the soil, which is beneficial to promoting the absorption of nutrients by plants.

[0084] Example 4: Effect of growth-promoting bacterial strain CZJ2 on the growth ability of wild barley

[0085] Simulated saline-alkali planting system: A mixed salt solution was added to the loess culture system to simulate the saline-alkali planting environment, and the growth-promoting effect of the strain on wild barley seedlings was verified by the experiment.

[0086] (1) Disinfect the surface of wild barley seeds, soak them in 95% alcohol for 2 minutes, stir them in 1% sodium hypochlorite solution for 3 minutes, rinse them with sterile water 10 times, keep them moist, germinate them in the dark at 25℃ for 2 days, and select germinated seeds with a sprout length of about 1 cm for sowing.

[0087] (2) Select seeds with relatively uniform sprout length after germination and sow them in loess pots. Inoculate and do not inoculate the seeds, and plant 9 seedlings in each treatment. Set up a salt-free control system and inoculate and do not inoculate the seeds in the same way.

[0088] (3) Experimental strain: CZJ2 strain; cultured in LB liquid medium at 28℃ and 180 rpm for 36 h; the bacterial culture was centrifuged at 8000 rpm for 10 min to obtain bacterial cells, washed once with physiological saline and then resuspended, and the OD was adjusted. 600 Within the range of 0.6-0.8, the inoculation amount is 50 mL / pot (inoculated in the soil, with 3 plants per pot), added every 3 days, and repeated twice.

[0089] (4) Prepare salt solutions with salt concentrations of 0 mmol / L, 200 mmol / L, 400 mmol / L, 600 mmol / L, and 800 mmol / L (NaCl:Na2SO4=1:1). After adding the bacterial culture, add 50 mL of salt solution to each container and set up a salt-free system as a control.

[0090] After treatment, the plants were placed in a smart greenhouse and given appropriate water every two days. After 7 days of cultivation, the plant height, dry weight, fresh weight, and root length of wild barley seedlings were measured to evaluate the effect of strain CZJ2 on the growth phenotype of wild barley.

[0091] The results are as follows Figures 8-9 As shown, at various salt and alkali concentrations, the plant height, root length, fresh weight, and dry weight of the plants in the bacterial treatment group were significantly higher than those in the control group without bacterial treatment. At a salt concentration of 0 mmol / L, the plant height, fresh weight, and dry weight of the plants in the bacterial treatment group were significantly higher than those in the control group without bacterial treatment; at a salt concentration of 200 mmol / L, the plant height of the CZJ2 group was significantly higher than that of the CK group; and at a salt concentration of 600 mmol / L, the fresh weight of the CZJ2 group was significantly higher than that of the CK group. These results indicate that strain CZJ2 promotes plant growth and can also alleviate salt and alkali stress, thus promoting the growth of wild barley under salt and alkali stress.

[0092] The embodiments described above are merely preferred embodiments of the present invention and are not intended to limit the scope of the present invention. Various modifications and improvements made by those skilled in the art to the technical solutions of the present invention without departing from the spirit of the present invention should fall within the protection scope defined by the claims of the present invention.

Claims

1. A Brucella intermedia CZJ2, characterized in that, The intermediate Brucella CZJ2 is preserved in China General Microbiological Culture Collection Center on October 20, 2025, with a preservation number of CGMCC No.36252 and a preservation address of No.3, Institute of Microbiology, Chinese Academy of Sciences, Beijing Chaoyang District, Beichen West Road 1st Courtyard 3rd.

2. A microbial inoculant, characterized in that, The intermediate Brucella CZJ2 or the bacterial suspension thereof according to claim 1.

3. Use of the intermediate Brucella CZJ2 according to claim 1 or the microbial inoculant according to claim 2 in nitrogen fixation, phosphorus solubilization, phosphorus dissolution, silicate dissolution and / or siderophore production.

4. Use of the intermediate Brucella CZJ2 according to claim 1 or the microbial inoculant according to claim 2 in promoting plant growth.

5. Use of the intermediate Brucella CZJ2 according to claim 1 or the microbial inoculant according to claim 2 in preparing a product for promoting plant growth.

6. Use according to claim 4 or 5, wherein the compound is ###0002### The plant comprises wild barley.

7. A method of promoting plant growth, characterized by, The method comprises the step of treating the plant with the intermediate Brucella CZJ2 or the bacterial suspension thereof according to claim 1.

8. The method of claim 7, wherein, The method comprises the step of inoculating the soil of the plant with the bacterial suspension of the intermediate Brucella CZJ2.

9. The method of claim 8, wherein, OD of the bacterial suspension 600 was 0.6-0.

8.

10. The method of claim 7, wherein, The plant comprises wild barley. The intermediate Brucella CZJ2 is preserved in China General Microbiological Culture Collection Center on October 20, 2025, with a preservation number of CGMCC No.36252 and a preservation address of No.3, Institute of Microbiology, Chinese Academy of Sciences, Beijing Chaoyang District, Beichen West Road 1st Courtyard 3rd. The intermediate Brucella CZJ2 or the bacterial suspension thereof according to claim 1.

3. Use of the intermediate Brucella CZJ2 according to claim 1 or the microbial inoculant according to claim 2 in nitrogen fixation, phosphorus solubilization, phosphorus dissolution, silicate dissolution and / or siderophore production.

4. Use of the intermediate Brucella CZJ2 according to claim 1 or the microbial inoculant according to claim 2 in promoting plant growth.

5. Use of the intermediate Brucella CZJ2 according to claim 1 or the microbial inoculant according to claim 2 in preparing a product for promoting plant growth. The plant comprises wild barley. The method comprises the step of treating the plant with the intermediate Brucella CZJ2 or the bacterial suspension thereof according to claim 1. The method comprises the step of inoculating the soil of the plant with the bacterial suspension of the intermediate Brucella CZJ2. The plant comprises wild barley.

Images