Alkali-reducing multifunctional salt-tolerant bacillus, microbial agent thereof and application of microbial agent

Abstract

The invention discloses an alkali-reducing multifunctional salt-tolerant bacillus, a microbial agent thereof and application of the alkali-reducing multifunctional salt-tolerant bacillus, the alkali-reducing multifunctional salt-tolerant bacillus and the microbial agent, the alkali-reducing multifunctional salt-tolerant bacillus is named as the salt-tolerant bacillus J-009, the salt-tolerant bacillus is preserved in the China General Microbiological Culture Collection Center on September 9, 2024, and the preservation number of the salt-tolerant bacillus is CGMCC No. 31901. The J-009 strain and the microbial fertilizer thereof have multiple functions, the effects of dissolving phosphorus, fixing nitrogen, producing iron, producing indoleacetic acid, producing extracellular polymeric substances and resisting rice blast can be achieved only by using a single microbial agent, metabolites of the J-009 strain comprise substances such as arabinose, glucose, enzymes and amino acid, and the J-009 strain and the microbial fertilizer thereof can also be applied to promoting growth of crops under alkali stress and salt stress. In addition, the strain can also be used as a soil conditioner, and has the effects of slowing down salinization of soil, increasing biomass of plants and promoting growth of rice.

Description

Technical Field

[0001] The present invention relates to the field of microbial technology, in particular to a multifunctional salt-tolerant Bacillus for reducing alkali in saline-alkali land, a microbial agent thereof and applications thereof. Background Art

[0002] The information disclosed in this background technology section is only intended to enhance some understanding of the overall background of the invention and should not be necessarily regarded as an admission or any form of suggestion that the information constitutes the prior art already known to those skilled in the art.

[0003] Soil salinization, a major limiting factor in agricultural production, poses several detrimental risks: first, it leads to an imbalance in soil nutrients and reduces soil fertility; second, it disrupts soil aggregate structure, affecting soil permeability and its ability to retain water and nutrients; and third, the high salt content disrupts the osmotic pressure balance of crop cells, inhibiting root absorption of water and nutrients, thereby affecting normal crop growth and development. These negative impacts severely restrict the sustainable development of agricultural production and have become a pressing agro-ecological issue requiring global resolution.

[0004] Currently, saline-alkali soils face three major challenges in agricultural production. First, environmental constraints: high salt concentrations hinder crop water absorption, resulting in poor soil aeration and permeability, reduced nutrient availability, and nutrient imbalance. Second, crop growth is hindered, with low seed germination rates, difficulty in seedling emergence, impeded root development, stunted plant growth, and significantly reduced yields. Third, agricultural production is constrained: the number of suitable salt-tolerant crops is limited, soil improvement costs are high, and economic returns are low. These issues severely restrict the agricultural development and utilization of saline-alkali land.

[0005] Therefore, researchers are turning their attention to environmentally friendly solutions, among which the application of microbial agents presents unique advantages. Through their diverse physiological and metabolic functions, microbial agents can achieve green and safe bio-improvement effects. They can not only effectively alleviate the adverse effects of saline-alkali stress on crop growth and improve saline-alkali soil fertility, but also promote the virtuous cycle of soil ecosystems. They provide innovative technical approaches for the sustainable development of saline-alkali land agriculture and are becoming an important research direction for the management and utilization of saline-alkali land.

[0006] However, the alkali-resistant microbial agents discovered so far are few in number and have only a single function. Most of them only have the function of reducing alkalinity. However, in actual application scenarios such as ecological restoration and agricultural production, it is often expected that microbial agents can have other beneficial functions in addition to regulating soil pH.

[0007] Therefore, it is imperative to screen out multifunctional strains and develop salt-tolerant and alkali-reducing growth-promoting microbial agents. Summary of the Invention

[0008] In view of the shortcomings of the existing technology, the present invention provides a multifunctional salt-tolerant Bacillus for reducing alkali in saline-alkali soil, a microbial agent thereof and applications thereof.

[0009] The technical solution adopted in the present invention is as follows: In the first aspect of the present invention, a salt-tolerant Bacillus J-009 ( Bacillus halotolerans ), isolated from the soil of Daqing soda saline-alkali land, its preservation number is CGMCC No 31901, the preservation date is: September 9, 2024, and the preservation unit is: General Microbiology Center of China Culture Collection Administration (Address: No. 3, No. 1 Beichen West Road, Chaoyang District, Beijing); After identification, the salt-tolerant Bacillus ( Bacillus halotolerans ) J-009 is a newly discovered strain of Bacillus halogenide, belonging to the Bacillaceae family and the genus Bacillus.

[0010] The halotolerant Bacillus J-009 strain described in this invention possesses multiple functions, including growth-promoting functions such as phosphate solubilization, nitrogen fixation, iron production, extracellular polymeric substances (EPS), and indoleacetic acid production. It also reduces soil pH and salinity, making it useful for soil improvement and rice blast resistance. Further research has shown that halotolerant Bacillus J-009 promoted rice seed germination under alkaline stress, increasing plant height, root length, and fresh weight by 35.63%, 11.89%, and 31.72%, respectively, compared to the control group, significantly promoting crop growth.

[0011] The salt-tolerant Bacillus J-009 of the present invention is Gram-positive and has a rod-shaped bacterial strain; the bacterial colonies are milky white, and wrinkles appear on the surface of the bacterial colonies in the late growth stage.

[0012] In a second aspect of the present invention, a microbial mixture is provided, characterized in that it contains at least the halogen-tolerant Bacillus subtilis J-009 strain of the present invention. The microbial mixture may contain other biocontrol bacteria or strains that promote plant growth or have alkali-reducing functions and microorganisms that are symbiotic with the halogen-tolerant Bacillus subtilis J-009 strain of the present invention.

[0013] In a third aspect of the present invention, a product comprising the halodurable Bacillus J-009 strain or the microbial mixture of the present invention is provided. The product may be a microbial agent, a microbial fertilizer, or a soil conditioner.

[0014] Based on its excellent biological properties, including phosphate solubilization, nitrogen fixation, alkali reduction, and growth promotion, Halophilic Bacillus J-009 can be used as an active ingredient in the preparation of microbial agents or microbial fertilizers, reducing the use of chemical fertilizers and increasing plant biomass. It can be directly processed into microbial agents or microbial fertilizers for field application. These can be made from fermentation broth or freeze-dried powder of the microorganism.

[0015] In addition, the preparation method of the microbial agent or microbial fertilizer is: fermenting the salt-tolerant Bacillus J-009 in a solid fermentation medium or a liquid culture medium directly or further processing (with a carrier, other additives, etc.) to prepare microbial agents or microbial fertilizers of different dosage forms, or further adding other fertilizers to make compound fertilizers.

[0016] Optionally, the product includes a carrier; the carrier may be a solid carrier or a liquid carrier. The solid carrier or liquid carrier is a conventional carrier material, wherein the solid carrier may be selected from clay, talc, kaolin, montmorillonite, white carbon, zeolite, silica, corn flour, soy flour, polyvinyl alcohol and / or polyglycol; the liquid carrier may be vegetable oil, mineral oil or water.

[0017] Optionally, the product is in the form of a wettable powder, a water dispersant, a water suspension, a dispersible oil suspension or other forms.

[0018] Optionally, the active ingredient of the product is halodurable Bacillus J-009, and the active ingredient can be present in the form of halodurable Bacillus J-009 bacteria, fermentation liquid or fermentation supernatant.

[0019] Preferably, in the product, the effective viable count of halodurable Bacillus J-009 is not less than 100 million / g.

[0020] In a fourth aspect of the present invention, a method for preparing a microbial agent is provided, comprising the following steps: The salt-tolerant Bacillus J-009 is inoculated into a liquid culture medium and cultured in a shaking flask at a temperature of 27-30° C. and a rotation speed of 150-200 r / min. When the strain grows to a logarithmic growth phase, the bacterial solution is diluted with sterile water or culture medium to obtain the microbial agent.

[0021] Preferably, the dilution range of the fermentation broth is such that the OD600 absorbance is between 0.5 and 0.8.

[0022] In a fifth aspect of the present invention, a fermentation broth comprising halodurable Bacillus J-009 is provided.

[0023] In a sixth aspect of the present invention, a fermentation method of the halodurable Bacillus J-009 is provided, wherein the halodurable Bacillus J-009 is inoculated into a fermentation medium for fermentation culture.

[0024] In a seventh aspect of the present invention, there is provided a use of the halodurable Bacillus J-009, the microbial mixture and / or the product in any of the following (1) to (3): (1) Application in phosphate solubilization, nitrogen fixation, iron production, and extracellular polymeric substances (EPS); (2) Application in reducing pH value of alkaline soil environment and improving soil; (3) Application in promoting plant growth under alkaline stress and / or salt stress.

[0025] In one or some embodiments of the present invention, in application (1), experiments have shown that the salt-tolerant Bacillus J-009 can dissolve organic phosphorus, inorganic phosphorus, fix nitrogen, produce iron, and produce EPS, and obviously has certain growth-promoting properties.

[0026] In one or some embodiments of the present invention, in application (2), the halogen-tolerant Bacillus J-009 has excellent salt-alkali tolerance and can grow at pH 6 to 10 and salt concentrations of 0.1% to 5%. It can also maintain a high bacterial concentration at pH 10. More importantly, the strain also has the ability to reduce salt and alkali, reducing the pH value of the liquid LB culture medium from 10 to 8.61 within 48 hours. In addition, the salt reduction rate can reach 16.7%, thereby improving the salinization of alkaline soil. Therefore, the halogen-tolerant Bacillus J-009 or the microbial mixture or product can be used to reduce the pH value and salinity of alkaline soil environments and be applied to improve soil.

[0027] In one or some embodiments of the present invention, in application (3), experiments have shown that the salt-tolerant Bacillus J-009 can improve the seed germination rate, plant height, root length and fresh weight of rice under alkali stress, indicating that the salt-tolerant Bacillus J-009 can alleviate the stress caused by alkali stress on plants, promote the growth of plants (such as rice) under alkali stress environment, and increase their yield; it also provides a basis for the role of the salt-tolerant and alkali-promoting bacteria of the present invention in promoting growth and reducing alkali.

[0028] Optionally, the plants include rice and soybean.

[0029] In an eighth aspect of the present invention, a method for promoting rice seed germination is provided, comprising the step of contacting rice seeds to be germinated with the halodurable Bacillus sp. J-009 strain of the present invention.

[0030] In a ninth aspect of the present invention, a method for promoting the growth of rice under alkaline stress is provided, comprising the step of contacting the rhizosphere surrounding environment of rice to be grown with the halophilic Bacillus J-009 strain of the present invention.

[0031] Preferably, the rhizosphere surrounding environment is rice rhizosphere soil.

[0032] Compared with the related art known to the inventors, one of the technical solutions of the present invention has the following beneficial effects: 1. The present invention provides a multifunctional strain of Bacillus halogenide J-009, which was screened from saline-alkali soil. The strain not only has excellent salt-alkali tolerance, but also can achieve the effects of solubilizing organic and inorganic phosphorus, fixing nitrogen, producing iron, EPS, and indoleacetic acid using only a single bacterial agent. The Bacillus halogenide J-009 bacterial agent can significantly improve the alkali tolerance of rice under alkali stress, mitigate the effects of soil salinization, promote rice growth, and increase rice biomass. On the other hand, it reduces the use of chemical fertilizers and protects the soil environment.

[0033] Based on the above comprehensive biological characteristics of halotolerant Bacillus J-009, this salt- and alkali-tolerant multifunctional strain and its microbial agent have broad application prospects.

[0034] 2. The preparation method of the microbial preparation of the halodurable Bacillus provided by the present invention is simple, has high production efficiency, low requirements on culture conditions, low production cost, short cycle, is suitable for the needs of industrial mass production, and is easy to promote and use. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] The accompanying drawings, which constitute a part of the specification of the present invention, are used to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute improper limitations on the present invention.

[0036] Figure 1 This is the colony morphology of the halodurable Bacillus J-009; Figure 2 This is the shape diagram of the strain of halodurable Bacillus J-009; Figure 3 This is the phylogenetic tree result of halodurable Bacillus J-009; Figure 4 Results of solubilization of inorganic and organic phosphorus by halotolerant Bacillus J-009; Figure 5 This is the result of the resistance of Bacillus halodurans J-009 to rice blast; Figure 6 This is the salt and alkali resistance result of the halotolerant Bacillus J-009; Figure 7To analyze the growth-promoting ability of halotolerant Bacillus J-009 on rice seeds under salt stress; Figure 8 To analyze the growth-promoting ability of halotolerant Bacillus J-009 on rice seeds under alkaline stress. DETAILED DESCRIPTION

[0037] It should be noted that the following detailed descriptions are exemplary and intended to provide further explanation of the present invention. Unless otherwise specified, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the art to which the present invention belongs.

[0038] It should be noted that the terms used herein are only for describing specific embodiments and are not intended to limit the exemplary embodiments according to the present invention. As used herein, unless the context clearly indicates otherwise, the singular form is intended to include the plural form. In addition, it should be understood that when the terms "comprise" and / or "include" are used in this specification, they indicate the presence of features, steps, operations and / or combinations thereof.

[0039] In order to enable those skilled in the art to more clearly understand the technical solution of the present invention, the technical solution of the present invention will be described in detail below with reference to specific embodiments.

[0040] Example 1 Isolation and screening of strain J-009 1. Experimental Methods Soil samples were collected from saline-alkali land in Daqing, Heilongjiang Province. 5 g of sealed soil sample was weighed and placed in a 100 mL Erlenmeyer flask containing 45 mL of sterile water. The sample was shaken on a shaker at 150-200 r / min for 30 min and thoroughly mixed to obtain a soil suspension with a concentration of 1 / 10. 0.5 mL of the above soil suspension was pipetted into a sterile centrifuge tube containing 4.5 mL of sterile water and mixed to a solution concentration of 1 / 100. The above steps were repeated to dilute the solution to a final concentration of 1 / 10000. A small amount of the diluted soil suspension was placed in a culture dish containing LB solid medium with a pH of 10 on a sterile clean bench and spread to obtain multiple bacterial strains. The strains were spread on LB solid medium and purified and cultured at 28°C for 5 days.

[0041] 2. Experimental Results and Analysis After screening and purification, a halogen-tolerant Bacillus J-009 was obtained, and the halogen-tolerant Bacillus J-009 was cultured in LB medium at a constant temperature of 28°C. Figure 1 shown.

[0042] Example 2 Identification of strain J-009 1. Morphological identification like Figure 1 As shown, J-009 is a Gram-positive bacterium, and electron microscopy shows that the strain is rod-shaped ( Figure 2 As shown); the colony is milky white, and wrinkles appear on the surface of the colony in the late growth stage, and spores are produced.

[0043] 2. Physiological and biochemical identification J-009 was subjected to physiological and biochemical characterization. The results of these characterizations are detailed in Table 1. As shown in Table 1, J-009 can hydrolyze D-sorbitol, glucose, and D-arabinose, and produce hydrogen sulfide, amylase, catalase, urease, cellulolytic enzyme, lipase, amino acids, and siderophores. Table 1. Physiological and biochemical characterization of strain J-009.

[0044] Table 1 Physiological and biochemical identification of strain J-009 3. Molecular Biological Identification On the basis of the above-mentioned morphological and physiological and biochemical identifications, the strain J-009 was further identified by molecular biology.

[0045] (1) Experimental methods In this study, 16S rRNA gene sequence analysis was used to identify the strains screened. PCR amplification was performed using the commonly used bacterial primers 27F (5′-AGAGTTTGATCCTGGCTCAG-3′) and 1492R (5′-GGTTACCTTGTTACGACTT-3′). The resulting 16S rRNA sequence was BLAST-associated with the NCBI database to confirm the strain's species. Gene sequences of other strains with high homology were also downloaded, and a phylogenetic tree was constructed using MEGA X software.

[0046] (2) Experimental results and analysis like Figure 3 As shown, J-009 and Bacillus halotolerans SW207 and ZB201702 (accession numbers: CP119073.1 and CP029364.1, respectively) are located on the third branch of the evolutionary tree and have a close relationship. The 16S rRNA sequence of the J-009 strain is 100% similar to that of SW207 and ZB201702. Therefore, it can be determined that the strain J-009 is a halophilic Bacillus. Bacillus halotolerans .

[0047] Example 3 Functional Identification of Strain J-009 1. Dissolving organic and inorganic phosphorus Inoculate J-009 strain on inorganic phosphorus and organic phosphorus plates and culture at 28℃±0.5℃ for 3-4 days. The strain is able to grow on the culture medium and has a transparent area near the strain, which indicates that it has the ability to solubilize phosphate. The results are as follows: Figure 4 A (soluble inorganic phosphorus) and 4B (soluble organic phosphorus) are shown.

[0048] 2. Function of producing indoleacetic acid The ability of the strain to produce indoleacetic acid was identified using Salkowski colorimetric solution. The specific method was to inoculate the halodurable Bacillus J-009 into LB liquid medium (4% NaCl, pH 8.5) containing tryptophan and culture it with shaking for 24 hours. The culture was centrifuged for 10 minutes, and the supernatant was mixed with an equal volume of Salkowski colorimetric solution. The solution was allowed to stand in the dark for 30 minutes until its color turned red, indicating its ability to produce indoleacetic acid. The secreted IAA content was 12.39±0.66 mg / L, as shown in Table 2.

[0049] 3. Extracellular polymeric substances (EPS) production function The bacterial suspension was inoculated at 5% v / v into the fermentation medium of the EPS-producing strain. The culture was continued for 3 days, followed by centrifugation for 15 minutes, and the resulting cells were dried at 105°C to constant weight. The supernatant was added with 95% ethanol and precipitated overnight at 4°C. The mixture was centrifuged for 30 minutes, the supernatant discarded, and the resulting precipitate dried at 105°C to constant weight. The calculated EPS yield was 0.581 ± 0.083 g / g (see Table 2).

[0050] Table 2 EPS and IAA production capacity of strain J-009 4. Blast resistance The plate confrontation method was used to verify the resistance of Bacillus halophilus J-009 to rice blast. The inhibition rate of J-009 on rice blast was 30.4%, and the inhibitory effect on rice blast was obvious. Figure 5 show.

[0051] Example 4 Determination of salt-alkali tolerance and salt-alkali reduction ability of strain J-009 1. Analysis of salt-alkali tolerance characteristics of strain J-009 J-009 was streaked on LB solid medium with 1%~5% NaCl and pH 8~10. The results showed that J-009 grew well on 1%~5% NaCl medium. At the same time, J-009 grew well on pH 8~10 medium. Figure 6 shown.

[0052] 2. Determination of the Salt and Alkali Reducing Ability of Strain J-009 (1) Alkali reduction ability In order to study the alkalinity-reducing ability of strain J-009, LB liquid medium with a pH of 10 was prepared and strain J-009 was inoculated into the medium. After culture at 28°C for 24 h, 36 h, 48 h, and 72 h, the pH change of the liquid medium was detected using a pH meter. The results are shown in Table 3. J-009 had the strongest alkalinity-reducing ability at 72 h, with the pH dropped to 8.61. The alkalinity-reducing rate was calculated to be 13.9%.

[0053] (2) Salt reduction capacity To investigate the salt-reducing ability of strain J-009, the NaCl concentration in the bacterial culture was determined using AgNO₃ titration, which reflects salt concentration. To 2 mL of bacterial culture, one drop of 10% potassium chromate solution was added as an indicator, and the solution was titrated with 0.1 mol / L AgNO₃ solution. The endpoint was the appearance of a brick-red precipitate that did not fade. The amount of AgNO₃ solution used was recorded, and the salt-reduction rate of J-009 was calculated to be 16.7%.

[0054] Table 3 Alkali-reducing ability of strain J-009 Example 5 Analysis of the Growth-Promoting Ability of Strain J-009 on Rice Seeds under Salt-Alkali Stress 1. Experimental Methods Inoculate the strain into LB liquid medium and incubate at 28°C for 48 hours. Centrifuge for 10 minutes, remove the supernatant, and resuspend the cells in sterile water to an OD600 of 0.5. Select uniformly sized, plump rice seeds, sterilize them with 75% ethanol for 30 minutes, and rinse with sterile water until no ethanol residue remains on the seed surface. Soak half of the treated seeds in the prepared strain suspension for 3 hours, while the other half remains uninoculated.

[0055] The experiment was conducted in sterile Petri dishes, with 16 rice seeds per group, replicated three times. The rice seeds were exposed to salt stress at different NaCl concentrations (0, 50, 100, and 150 mmol / L), as well as alkaline stress at different pH gradients (8, 9, and 10). After incubation at 28°C in the dark for 7 days, root and shoot lengths were measured.

[0056] 2. Experimental Results and Analysis (1) Growth-promoting effect on rice seeds under salt stress With the increase of salt concentration, the root length and shoot length of rice seeds in the control group and the treatment group gradually decreased. However, compared with the control group, the root length and shoot length of rice seeds treated with J-009 increased significantly under the salt stress of clear water and 50 mmol / L, 100 mmol / L, and 150 mmol / L NaCl. Figure 7 shown.

[0057] (2) Growth-promoting effect on rice seeds under stress As the pH value increased, the root length and sprout length of rice seeds in the control group and the treatment group gradually decreased. However, compared with the control group, the root length and sprout length of rice seeds treated with J-009 under different alkaline stress conditions of pH 8, pH 9, and pH 10 increased significantly. Figure 8 shown.

[0058] Example 6 Effect of strain J-009 on rice growth under saline-alkali stress 1. Experimental methods Rice seeds were soaked in clean water for one day, germinated in an incubator at 28°C for two days, and then sown in hydroponic pots. The hydroponic pots in the saline-alkali stress environment were watered with water at pH 8.5, while the control pots were watered with clean water twice a week. The first inoculation was performed after approximately 10 days of growth, followed by a second inoculation of 5 mL of J-009 bacterial solution at an OD value of 1.0 approximately one week later. No inoculation was performed in the control pots.

[0059] The rice pot experiment was carried out in an artificial climate chamber of the Jiamusi Branch of Heilongjiang Academy of Agricultural Sciences. The temperature was 28°C, the photoperiod was 12h / 12h, the pH of the saline-alkali stressed water environment was 8.5, the salt concentration was 0.3%, and the conductivity was 225uS / cm. The pH of normal water was 6.1 and the conductivity was 9.57uS / cm.

[0060] The following four treatment groups were set up for rice: ① Blank control group (normal water with a pH of 6.1, not inoculated with bacteria); ② Salt-alkali stress treatment group (alkaline water with a pH of 8.5 and a salt concentration of 0.6%, without inoculation); ③ Salt-alkali stress and J-009 bacterial solution were co-treated (28°C, inoculated when the OD value of the bacterial solution was adjusted to 1.0 after 24 h of culture); ④ Treat with normal water and J-009 bacterial solution together (28℃, inoculate when the OD value of the bacterial solution is adjusted to 1.0 after 24 hours of culture).

[0061] The growth indicators (plant height, root length and fresh weight) of the rice plants treated with the above methods were measured after they had grown for 4 weeks.

[0062] 2. Experimental Results and Analysis As shown in Table 4, the use of bacterial solution treatment can effectively promote the growth of rice. Compared with the saline-alkali stress environment, the treatment with the addition of J-009 bacterial solution increased the plant height, root length, and fresh weight of rice by 14.5%, 15.9%, 38.1%, and 33.9%, respectively. This bacterial solution treatment effectively alleviated the stress of the saline-alkali environment on the rice seedlings themselves and also significantly promoted the growth and development of rice.

[0063] Table 4 Effects of J-009 on rice growth under saline-alkali stress The above embodiments are preferred implementation modes of the present invention, but the implementation modes of the present invention are not limited to the above embodiments. Any other changes, modifications, substitutions, combinations, and simplifications that do not deviate from the spirit and principles of the present invention should be considered as equivalent replacement methods and are included in the scope of protection of the present invention.

Claims

1. A halogen-tolerant Bacillus J-009, characterized in that: The bacterium was named as Halotolerant Bacillus Bacillus halotolerans ), deposited in the General Microbiology Center of China Culture Collection of Microorganisms on September 9, 2024, with the deposit number: CGMCC No 31901, and the deposit unit address: No. 3, Yard 1, Beichen West Road, Chaoyang District, Beijing.

2. A microbial mixture, characterized in that: The method comprises at least the halodurable Bacillus J-009 according to claim 1.

3. A product comprising the halodurable Bacillus J-009 according to claim 1 or the microbial mixture according to claim 2.

4. The product according to claim 3, characterized in that The product is a microbial agent, microbial fertilizer or soil conditioner; The active ingredient of the product is the bacteria, fermentation liquid or fermentation supernatant of the halotolerant Bacillus J-009 according to claim 1; The product is in the form of a wettable powder, a water dispersant, a water suspension or a dispersible oil suspension.

5. A method for preparing a microbial agent, characterized in that: It includes the following steps: The salt-tolerant Bacillus J-009 according to claim 1 is inoculated into a liquid culture medium and cultured in a shake flask at a temperature of 27 to 30° C. and a rotation speed of 150 to 200 r / min. When the strain grows to the logarithmic growth phase, the bacterial solution is diluted with sterile water or culture medium to obtain the microbial agent.

6. A fermentation broth comprising halodurable Bacillus J-009.

7. A fermentation method of the halodurable Bacillus J-009, characterized in that: The halodurable Bacillus J-009 is inoculated into a fermentation medium for fermentation culture.

8. Use of the halodurable Bacillus J-009 according to claim 1, the microbial mixture according to claim 2, and / or the product according to claim 3 in any of the following (1) to (3): (1) Application in phosphate solubilization, nitrogen fixation, iron production, and extracellular polymeric substances (EPS); (2) Application in reducing pH value of alkaline soil environment and improving soil; (3) Use in promoting the growth of plants under alkaline stress and / or salt stress, wherein the plants are rice or soybean.

9. A method for promoting rice seed germination, characterized in that: The method comprises the step of contacting rice seeds to be germinated with the halotolerant Bacillus J-009 according to claim 1.

10. A method for promoting the growth of rice under alkaline stress, characterized in that: The method comprises the step of contacting the rhizosphere surrounding environment of rice to be grown with the halotolerant Bacillus J-009 according to claim 1.

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