A salt-tolerant Aeromonas bivalvium BM-B and its applications

Abstract

The present invention discloses a salt-alkali tolerant Aeromonas strain BM-B and its application in promoting plant growth. This strain belongs to Aeromonas bivalvium and was deposited at the China Center for Type Culture Collection on November 22, 2023. This strain has strong salt and alkali tolerance characteristics. The NaCl concentration it can tolerate for growth is 1-10% (w / v), and the pH value it can tolerate is 7.0-9.0. It has the ability to produce metabolites such as indoleacetic acid, indolepyruvic acid, betaine, choline, isoleucine, valine, tyrosine, proline, and tryptophan. Moreover, under both salt-free stress and salt stress conditions, it can promote plant growth and improve plant salt resistance.

Description

Technical Field

[0001] The present invention belongs to the technical field of microbiology, and particularly relates to a salt-tolerant and alkali-tolerant Aeromonas bivalvium BM-B and its application. Background Art

[0002] Saline-alkali lands generally have problems such as poor physical and chemical properties of the soil and poor growth of crops. Reasonable development and utilization of these saline-alkali land resources is of great significance.

[0003] Microorganisms play important roles in aspects such as plant health, nutrient absorption and metabolic functions, as well as soil health and nutrient cycling, and can improve the adaptability of plants under biotic and abiotic environmental stresses. In addition, microbial-based biofertilizers and biostimulants have advantages such as broad-spectrum, high efficiency, safety, pollution-free, and relatively less energy consumption in production, and can meet the common needs of agricultural soil health, high and efficient crop production, and environmental ecological protection.

[0004] Saline-alkali soil contains rich microbial resources. Currently, the discovered microbial strains that can be used for the development and utilization of saline-alkali lands mainly belong to various salt-tolerant and alkali-tolerant genera such as Halomonas, Bacillus, Pseudomonas, and Zhihengliuella. Regarding the microorganisms belonging to the genus Aeromonas, except that the media strain has been reported to have the effects of enhancing plant stress resistance and promoting plant growth, there has been no relevant report on the bivalvium strain having the effects of alleviating plant salt damage and promoting plant growth. In addition, no study has pointed out that the Aeromonas bivalvium strain can produce metabolites such as indoleacetic acid, indolepyruvic acid, betaine, choline, isoleucine, valine, tyrosine, proline, and tryptophan, which have the effects of promoting plant growth and improving plant stress resistance. Summary of the Invention

[0005] The purpose of the present invention is to overcome the deficiencies of the prior art and provide a salt-tolerant and alkali-tolerant Aeromonas bivalvium BM-B. This strain has strong salt-tolerant and alkali-tolerant characteristics. The NaCl concentration that its growth can tolerate is 1-10% (w / v), and the pH value it can tolerate is 7.0-9.0. It can produce metabolites such as indoleacetic acid, indolepyruvic acid, betaine, choline, isoleucine, valine, tyrosine, proline, and tryptophan, which have the effects of promoting plant growth and improving plant stress resistance, and can promote plant growth under both salt-free stress and salt stress conditions.

[0006] The present invention is achieved through the following technical solutions:

[0007] The present invention provides a salt-tolerant Aeromonas bivalvium BM-B isolated from the rhizosphere soil of Imperata cylindrica in saline-alkali land in Haixing County, Cangzhou City, Hebei Province, China. This strain has been deposited. The depositary institution is the China Center for Type Culture Collection, the deposit address is Wuhan University, Wuhan, China, the deposit date is November 22, 2023, and the deposit number is CCTCC NO: M 20232297.

[0008] For the salt-tolerant Aeromonas bivalvium BM-B described above, its colony is white and protuberant, and the edge of the colony is smooth.

[0009] For the salt-tolerant Aeromonas bivalvium BM-B described above, its 16S rDNA sequence is as shown in SEQ ID NO.1 and belongs to the species Aeromonas bivalvium.

[0010] For the salt-tolerant Aeromonas bivalvium BM-B described above, the NaCl concentration it can tolerate for growth is 1-10% (w / v), and the pH value it can tolerate is 7.0-9.0.

[0011] The salt-tolerant Aeromonas bivalvium BM-B can produce metabolites such as indoleacetic acid, indolepyruvic acid, betaine, choline, isoleucine, valine, tyrosine, proline, tryptophan, etc., which have the effects of promoting plant growth and improving plant stress resistance.

[0012] For the salt-tolerant Aeromonas bivalvium BM-B described above, under the condition of no salt stress, it can promote plant growth. Taking wheat plants as an example, it is mainly manifested as a 13.09%-14.37% increase in above-ground fresh weight, an 18.73% increase in above-ground dry weight, and a 9.75% increase in plant height.

[0013] For the salt-tolerant Aeromonas bivalvium BM-B described above, under the salt stress condition of 3.10 g / kg (NaCl / dry soil), it can promote plant growth and improve plant salt tolerance. Taking wheat plants as an example, it is mainly manifested as a 15.00% increase in above-ground fresh weight and a 3.58% increase in plant height.

[0014] For the salt-tolerant Aeromonas bivalvium BM-B described above, under the salt stress condition of 5.85 g / kg (NaCl / dry soil), it can promote plant growth and improve plant salt tolerance. Taking wheat plants as an example, it is mainly manifested as a 12.39% increase in above-ground fresh weight and a 10.60% increase in above-ground dry weight.

[0015] Another object of the present invention is to provide an application of Aeromonas bivalvium BM-B, a salt- and alkali-tolerant bacterium, in promoting plant growth.

[0016] Another object of the present invention is to provide a microbial inoculant or biological fertilizer prepared using Aeromonas bivalvium BM-B, a salt- and alkali-tolerant bacterium.

[0017] Another object of the present invention is to provide an application of a microbial inoculant or biological fertilizer prepared using Aeromonas bivalvium BM-B, a salt- and alkali-tolerant bacterium, in promoting plant growth.

[0018] Another object of the present invention is to provide an application of a microbial inoculant or biological fertilizer prepared using Aeromonas bivalvium BM-B, a salt- and alkali-tolerant bacterium, in enhancing the salt resistance or alkali resistance of plants.

[0019] Another object of the present invention is to provide a biostimulant prepared using the metabolites of Aeromonas bivalvium BM-B, a salt- and alkali-tolerant bacterium.

[0020] Another object of the present invention is to provide an application of a biostimulant prepared using the metabolites of Aeromonas bivalvium BM-B, a salt- and alkali-tolerant bacterium, in promoting plant growth.

[0021] Another object of the present invention is to provide an application of a biostimulant prepared using the metabolites of Aeromonas bivalvium BM-B, a salt- and alkali-tolerant bacterium, in enhancing the salt resistance or alkali resistance of plants.

[0022] The advantages and beneficial effects of the present invention are as follows:

[0023] The salt- and alkali-tolerant Aeromonas bivalvium BM-B described in the present invention has strong salt- and alkali-tolerant characteristics and can tolerate an NaCl concentration of 1-10% (w / v) and a pH value of 7.0-9.0. Therefore, it is suitable for soils with different degrees of salinization and alkalization within the range of 1%-10% NaCl salt content and a pH value of 7.0-9.0, and has a wide range of environmental adaptability and application space.

[0024] The halotolerant Aeromonas bivalvium BM-B of the present invention has excellent characteristics of promoting plant growth and improving plant salt tolerance under both non-salt stress and salt stress conditions, mainly manifested as increases in indicators such as the fresh weight above ground, dry weight above ground, and plant height of wheat. Therefore, it is suitable for the preparation of microbial inoculants and biological fertilizers, providing resource and technical support for the replacement or partial replacement of the use of chemical fertilizers and the development of microbial-based biotechnology for saline-alkali land improvement, and thus facilitating the coordinated development of high-yield and high-efficiency crop production and environmental ecological protection in agricultural production.

[0025] In addition, the halotolerant Aeromonas bivalvium BM-B of the present invention can produce metabolites such as indoleacetic acid, indolepyruvic acid, betaine, choline, isoleucine, valine, tyrosine, proline, and tryptophan. These metabolites can play various roles in agricultural production, including promoting plant growth and development, increasing seed germination rate, enhancing plant tolerance to osmotic stress, and improving plant nutrient utilization ability, photosynthesis efficiency, antioxidant ability, and stress resistance. Therefore, it is suitable for the preparation of biostimulants mainly composed of indoleacetic acid, indolepyruvic acid, betaine, choline, isoleucine, valine, tyrosine, proline, and tryptophan, providing resource support for the development of microbial-based biotechnology for improving agricultural quality and efficiency, and thus facilitating the increase in crop yield and improvement in quality in agricultural production.

[0026] Preservation Information

[0027] Aeromonas bivalvium BM-B, this strain has been preserved. Preservation unit: China Center for Type Culture Collection. Preservation address: Wuhan University, Wuhan, China. Preservation date: November 22, 2023. Preservation number: CCTCC NO: M 20232297. Brief Description of the Drawings

[0028] Figure 1 is the colony observation diagram of the halotolerant Aeromonas bivalvium BM-B of the present invention, (a) front, (b) back;

[0029] Figure 2 is the phylogenetic tree of the 16S rDNA sequence of the halotolerant Aeromonas bivalvium BM-B of the present invention;

[0030] Figure 3 is the observation diagram of the promotion of wheat growth by the halotolerant Aeromonas bivalvium BM-B of the present invention under the salt stress condition of 3.10 g / kg (NaCl / dry soil);

[0031] Figure 4 Effect of Aeromonas bivalvium BM-B, a halotolerant bacterium of the present invention, on the plant height of wheat under salt stress conditions of 3.10 g / kg (NaCl / dry soil).

[0032] Figure 5 Effect of Aeromonas bivalvium BM-B, a halotolerant bacterium of the present invention, on the fresh aboveground weight of wheat under salt stress conditions of 3.10 g / kg (NaCl / dry soil).

[0033] Figure 6 Observation diagram of the promotion of wheat growth by Aeromonas bivalvium BM-B, a halotolerant bacterium of the present invention, under salt stress conditions of 5.85 g / kg (NaCl / dry soil).

[0034] Figure 7 Effect of Aeromonas bivalvium BM-B, a halotolerant bacterium of the present invention, on the fresh aboveground weight of wheat under salt stress conditions of 5.85 g / kg (NaCl / dry soil).

[0035] Figure 8 Effect of Aeromonas bivalvium BM-B, a halotolerant bacterium of the present invention, on the dry aboveground weight of wheat under salt stress conditions of 5.85 g / kg (NaCl / dry soil).

[0036] Figure 9 Types and relative abundances of metabolites of Aeromonas bivalvium BM-B, a halotolerant bacterium of the present invention.

[0037] For those of ordinary skill in the art, without creative efforts, other relevant drawings can be obtained based on the above drawings. Detailed implementation manners

[0038] In order to enable those skilled in the art to better understand the solution of the present invention, the technical solution of the present invention will be further described below in conjunction with specific embodiments.

[0039] Example 1: Isolation and purification of Aeromonas bivalvium BM-B

[0040] Sample source: Rhizosphere soil of Imperata cylindrica in saline-alkali land in Haixing County, Cangzhou City, Hebei Province, China.

[0041] LB medium (solid): tryptone 10 g / L, yeast extract 5 g / L, sodium chloride 50 g / L, agar 20 g / L. After adjusting the pH value with 5 M / L NaOH, autoclave at 121 °C for 30 min.

[0042] LB medium (liquid): tryptone 10 g / L, yeast extract 5 g / L, sodium chloride 50 g / L. After adjusting the pH value with 5 M / L NaOH, autoclave at 121 °C for 30 min.

[0043] Isolation and purification steps: 1) Collect the roots of Imperata cylindrica in the saline-alkali land of Haixing County, Cangzhou City, Hebei Province, China. After shaking off the soil on the root surface, put them into a sterile 50 mL centrifuge tube, add sterile water and vortex, then the original rhizosphere soil solution can be obtained; 2) Let it stand, take an appropriate amount of supernatant, and sequentially dilute it with sterile water to obtain 10 -1 、10 -2 and 10 -3 soil suspensions, respectively coat them on the solid LB medium containing 5% NaCl, and place them in an incubator at 28 °C for cultivation; 3) Repeatedly pick single colonies with different morphologies and colors for streak plate culture, and subculture them for 4 - 5 generations respectively, then pure and morphologically consistent single colonies can be obtained.

[0044] Example 2: Identification of the salt-tolerant Aeromonas bivalvium BM-B

[0045] 1) Biological characteristic identification

[0046] The colonies of strain BM-B on the LB medium are white and protuberant, and the edges of the colonies are smooth ( Figure 1 ).

[0047] 2) Systematic classification identification

[0048] The genomic DNA of strain BM-B was extracted using the kit TIANamp Bacteria DNA Kit (Tiangen, Beijing) according to its operating steps. The 16S rDNA sequence of strain BM-B was amplified using primers 27F and 1492R. The PCR reaction system was 50 μL, which contained 10 μL of EasyTaq buffer, 5 μL of dNTPs, 0.5 μL of primer 27F, 0.5 μL of primer 1492R, 1.5 μL of DNA template, 2 μL of Easy Taq DNA polymerase, and finally sterile ultrapure water was added to 50 μL. The PCR reaction program was: (i) pre-denaturation at 94 °C for 5 min; (ii) 35 cycles of denaturation at 94 °C for 1 min, annealing at 55 °C for 1 min, and extension at 72 °C for 1.5 min; (iii) the final extension condition was 72 °C for 10 min. The PCR amplification product was submitted to Sangon Biotech (Shanghai) Co., Ltd. for sequencing, and the 16S rDNA of the sequenced strain BM-B was as described in Sequence Listing SEQ ID NO.1.

[0049] The obtained sequenced was subjected to homology comparison through the NCBI database (https: / / www.ncbi.nlm.nih.gov). The results showed that the 16S rDNA sequences of strain BM-B had similarity of up to 99.86%, 99.58%, 99.79%, and 99.65% with the sequences of Aeromonas bivalvium strain TY172-19, D15, 665N, and 868E, respectively, and were closely related in the phylogenetic tree ( Figure 2 ). Meanwhile, the obtained sequenced was subjected to homology comparison through the EzBioCloud database (https: / / www.ezbiocloud.net / identify). The results showed that the 16S rDNA sequence of strain BM-B had similarity of up to 99.03% with the sequence of Aeromonas bivalvium strain CECT 7113(T). Therefore, it was named Aeromonas bivalvium BM-B.

[0050] Example 3: Evaluation of the salt and alkali tolerance of Aeromonas bivalvium BM-B

[0051] Pick a single colony of Aeromonas bivalvium BM-B on solid LB medium and inoculate it into 50 mL of liquid LB medium. After culturing at 28°C and 150 r / min for 48 h, inoculate it onto LB solid media with NaCl solution concentrations of 1%, 5%, 10%, 15%, and 20% and pH values of 7.0, 8.0, and 9.0 in pairwise combinations for streak culture. The results show that Aeromonas bivalvium BM-B can grow in media with NaCl concentrations of 1% - 10% and pH values of 7.0 - 9.0.

[0052] Example 4: Effect of Aeromonas bivalvium BM-B, a halotolerant and alkalitolerant bacterium, on wheat growth under salt stress conditions of 3.10 g / kg (NaCl / dry soil)

[0053] Preparation of Aeromonas bivalvium BM-B bacterial solution: Pick a single colony of Aeromonas bivalvium BM-B on solid LB medium and inoculate it into 50 mL of liquid LB medium. Culture at 28°C and 160 r / min for 48 h. Take an appropriate amount of the bacterial solution and inoculate it into 600 mL of liquid LB medium. After culturing at 28°C and 160 r / min for 48 h, centrifuge at 8000 rpm for 15 min to collect the bacteria. Wash the bacteria twice with sterile water and then resuspend the bacteria with sterile water to obtain the Aeromonas bivalvium BM-B bacterial solution.

[0054] Wheat pot experiment: Set up a control treatment (denoted as Control) and a treatment with the addition of Aeromonas bivalvium BM-B bacterial solution (denoted as BM-B), as well as different salt content treatments of 0 g / kg (NaCl / dry soil) and 3.10 g / kg (NaCl / dry soil), for a total of 4 treatments, with each treatment repeated 3 times ( Figure 3)。Use non-saline-alkali farmland soil that has passed through a 2-mm sieve and is well-mixed, and divide it into portions of 325.37 g of dry soil per pot to plant "Malang No. 1" wheat. Plant 12 seeds per pot (recorded as the 1st day), and start thinning the seedlings after they emerge neatly (the 5th day). Finally, retain 4 wheat seedlings per pot. The cultivation conditions are 25°C, 16 h of light / 8 h of darkness. When the wheat seedlings are strong (the 8th day), treat them with an 8 g / L NaCl solution for salt stress, and use sterile water for the control treatment. Water once every 1 - 3 days, and continue watering until the soil NaCl content reaches approximately 3.10 g / kg (NaCl / dry soil), then stop watering with the NaCl solution and use sterile water for subsequent watering. At the same time, pour 10 mL and 20 mL of Aeromonas bivalvium BM-B bacterial solution into the soil on the 7th day and the 20th day respectively, and pour sterile water for the control treatment. After 52 days of cultivation, the experimental results show that: 1) The wheat treated with the Aeromonas bivalvium BM-B bacterial solution grows better than the wheat in the control treatment, and the leaf color is greener ( Figure 3 ); 2) Measure and count the wheat plant height and above-ground fresh weight indicators, and it is found that under the conditions of 0 g / kg (NaCl / dry soil) without salt stress and 3.10 g / kg (NaCl / dry soil) with salt stress, the application of Aeromonas bivalvium BM-B bacterial solution promotes the growth of wheat and improves the salt tolerance of wheat, mainly manifested as the wheat plant height increases by 9.75% and 3.58% respectively ( Figure 4 ), and the above-ground fresh weight of wheat increases by 13.09% and 15.00% respectively ( Figure 5 ).

[0055] In summary, the salt-tolerant Aeromonas bivalvium BM-B described in the present invention can promote the growth of wheat under both the conditions of no salt stress and 3.10 g / kg (NaCl / dry soil) salt stress. These promoting effects are mainly manifested as an increase in the plant height and above-ground fresh weight of wheat plants, and alleviation of the damage of salt stress to wheat.

[0056] Example 5: Effect of Aeromonas bivalvium BM-B on wheat growth under 5.85 g / kg (NaCl / dry soil) salt stress

[0057] Preparation of Aeromonas bivalvium BM-B bacterial solution tolerant to saline-alkali: Pick a single colony of Aeromonas bivalvium BM-B on solid LB medium and inoculate it into 50 mL of liquid LB medium. Incubate at 28 °C and 150 r / min for 48 h. Take an appropriate amount of the bacterial solution and inoculate it into 600 mL of liquid LB medium. After incubating at 28 °C and 150 r / min for 48 h, centrifuge at 8000 rpm for 15 min to collect the bacterial cells. Wash the bacterial cells twice with sterile water and then resuspend the bacterial cells with sterile water to obtain the Aeromonas bivalvium BM-B bacterial solution.

[0058] Wheat pot experiment: Set up a control treatment (denoted as Control) and a treatment with Aeromonas bivalvium BM-B bacterial solution (denoted as BM-B), as well as different salt content treatments of 0 g / kg (NaCl / dry soil) and 5.85 g / kg (NaCl / dry soil), for a total of 4 treatments, with each treatment repeated 3 times ( Figure 6 ). Use non-saline-alkali farmland soil that has passed through a 2-mm sieve and is well-mixed, and divide it into portions of 1.10 kg of dry soil per pot to plant the "Xiaoyan 60" wheat. Sow 12 seeds per pot (recorded as the 1st day), and start thinning after the seedlings emerge evenly (the 5th day). Finally, retain 4 wheat seedlings per pot. The culture conditions are 25 °C, 16 h light / 8 h dark. When the wheat seedlings are neat and strong (the 7th day), conduct salt stress treatment with 200 mM NaCl solution and control treatment with sterile water, and irrigate once every 2 - 4 days. Continue irrigation until the soil NaCl content reaches approximately 5.85 g / kg (NaCl / dry soil), then stop using the NaCl solution for irrigation and use sterile water for subsequent irrigation. At the same time, irrigate the Aeromonas bivalvium BM-B bacterial solution into the soil around the wheat roots for treatment, and irrigate sterile water for the control treatment. The culture conditions are 25 ± 5 °C during the day, 20 ± 5 °C at night, 16 h light / 8 h dark. After 56 days of cultivation, the experimental results show that: 1) The wheat treated with Aeromonas bivalvium BM-B bacterial solution grows better than the control treatment, and the leaf color is greener ( Figure 6 ); 2) Measure and statistically analyze the above-ground fresh weight and above-ground dry weight indicators of wheat. It is found that under the conditions of no salt stress of 0 g / kg (NaCl / dry soil) and salt stress of 5.85 g / kg (NaCl / dry soil), the application of Aeromonas bivalvium BM-B bacterial solution promotes the growth of wheat and improves the salt tolerance of wheat, mainly manifested as the above-ground fresh weight increases by 14.37% and 12.39% respectively ( Figure 7 ), and the above-ground dry weight increases by 18.73% and 10.60% respectively ( Figure 8 ).

[0059] In summary, the salt-tolerant Aeromonas bivalvium BM-B of the present invention can promote the growth of wheat under both non-salt stress and salt stress conditions of 5.85 g / kg (NaCl / dry soil). These promoting effects are mainly manifested as an increase in the above-ground fresh weight and above-ground dry weight of wheat plants, and alleviation of the damage caused by salt stress to wheat.

[0060] Example 6: Determination of the metabolites of the salt-tolerant Aeromonas bivalvium BM-B

[0061] Pick a single colony of Aeromonas bivalvium BM-B on a solid LB medium and inoculate it into 50 mL of liquid LB medium. Culture at 28 °C and 160 r / min for 48 h. Take an appropriate amount of the Aeromonas bivalvium BM-B bacterial solution and inoculate it into 50 mL of LB liquid medium (containing L-tryptophan at a final concentration of 2 mg / mL). Set 6 replicates and culture for 15 days at 28 °C and 160 rpm. Then, collect the supernatant by centrifugation at 8000 rpm for 5 min (denoted as BM-B). At the same time, use 50 mL of LB liquid medium (containing L-tryptophan at a final concentration of 2 mg / mL) without inoculating the Aeromonas bivalvium BM-B bacterial solution as a control (denoted as Control), and set 6 replicates. Store the above-mentioned supernatant and control samples in a -80 °C refrigerator and submit them to Guangdong Magigene Technology Co., Ltd. for metabolome detection and analysis. The results show that the metabolites of the salt-tolerant Aeromonas bivalvium BM-B of the present invention are diverse, and the relative abundances of various metabolites such as indoleacetic acid, indolepyruvic acid, betaine, choline, isoleucine, valine, tyrosine, proline, and tryptophan are relatively high. A large amount of research data shows that these metabolites, as important plant growth regulators, osmotic regulators, nutrients, and insecticides, can play an important role in improving the stress resistance of plants such as salt resistance, alkali resistance, drought resistance, disease resistance, high temperature resistance, and low temperature resistance, and promoting plant growth and development through various ways such as promoting cell differentiation, cell elongation, rooting, and enhancing plant root activity (e.g., indoleacetic acid, indolepyruvic acid, and choline), maintaining the osmotic balance between the plant cytoplasm and the external environment (e.g., betaine and proline), participating in various physiological activities and endogenous hormone synthesis of plants (e.g., tryptophan), and disrupting the nervous system and reproduction of pests (e.g., choline) Figure 9 ).

[0062] As described in Example 1, the halotolerant and alkalitolerant Aeromonas bivalvium BM-B of the present invention is derived from the rhizosphere soil of the halophyte Imperata cylindrica in the saline-alkali land of Haixing County, Cangzhou City, Hebei Province, China. At the same time, as described in Example 3, the halotolerant and alkalitolerant Aeromonas bivalvium BM-B of the present invention has strong salt- and alkali-tolerant characteristics, and can tolerate a NaCl concentration of 1-10% (w / v) and a pH value of 7.0-9.0. In addition, as described in Example 6, it can produce various metabolites such as indoleacetic acid, indolepyruvic acid, betaine, choline, isoleucine, valine, tyrosine, proline, and tryptophan during its growth and reproduction processes, and these metabolites have the effects of improving the stress resistance of plants and promoting the growth and development of plants. Therefore, the halotolerant and alkalitolerant Aeromonas bivalvium BM-B of the present invention has the ability to grow and reproduce in soils with different degrees of salinization within the ranges of 1%-10% NaCl salt content and pH value of 7.0-9.0. The metabolites it produces, such as betaine, choline, isoleucine, and proline, can play an active role in improving the stress resistance of plants such as salt and alkali resistance. At the same time, the metabolites it produces, such as indoleacetic acid, indolepyruvic acid, valine, tyrosine, and tryptophan, can play an active role in regulating the growth and development of plants, thereby promoting the growth of plants in saline-alkali land.

[0063] The microbial inoculant or biological fertilizer based on the halotolerant and alkalitolerant Aeromonas bivalvium BM-B, as well as the biostimulant or plant growth regulator based on the metabolites of the halotolerant and alkalitolerant Aeromonas bivalvium BM-B, can directly or indirectly regulate the growth and development, nutrient absorption and metabolic functions of plants, and promote plant growth, improve the adaptability of plants under biotic and abiotic environmental stresses, and improve the yield and quality of crops by means of improving soil structure, increasing soil fertility, promoting the activity of beneficial soil microorganisms, and balancing the soil microecosystem. At the same time, as described in Examples 4 and 5, the pot experiments based on wheat plants verified that the halotolerant and alkalitolerant Aeromonas bivalvium BM-B of the present invention has the effects of promoting plant growth and improving plant salt tolerance. Therefore, the microbial inoculant or biological fertilizer based on the halotolerant and alkalitolerant Aeromonas bivalvium BM-B of the present invention, as well as the biostimulant or plant growth regulator, can be applied to other plants or crops and play the same role during their growth processes.

[0064] The above has made an exemplary description of the present invention. It should be noted that without departing from the core of the present invention, any simple deformation, modification or equivalent substitution that can be made by those skilled in the art without creative labor falls within the protection scope of the present invention.

[0065] SEQ ID NO:1

[0066] >BM-B_16S rDNA

[0067] >B_1443bp

[0068]

Claims

1. A salt-tolerant Aeromonas Aeromonas bivalvium BM-B, with the preservation number of CCTCC NO: M20232297.

2. An Aeromonas halotolerans as described in claim 1 Aeromonas bivalvium Use of BM-B in promoting plant growth, wherein the plant is wheat.

3. A halotolerant Aeromonas as described in claim 1 Aeromonas bivalvium Use of BM-B in enhancing the salt resistance or alkali resistance of plants, wherein the plant is wheat.

4. An Aeromonas halotolerans according to claim 1 Aeromonas bivalvium Use of BM-B in increasing the plant height of crops or increasing the fresh weight or dry weight of the above-ground parts of crops.

5. A culture or processed product thereof of Aeromonas halotolerans Aeromonas bivalvium BM-B as described in claim 1.

6. A plant growth regulator, characterized in that, Containing the alkaliphilic and halotolerant Aeromonas Aeromonas bivalvium as described in claim 1, BM-B or the culture or its processed product as described in claim 5.

7. A bio-fertilizer containing the alkaliphilic and halotolerant Aeromonas Aeromonas bivalvium BM-B or its fermentation product as described in claim 1.

8. A biostimulant, characterized in that, Containing the alkaliphilic and halotolerant Aeromonas as described in claim 1 Aeromonas bivalvium BM-B or the culture or its processed product as described in claim 5.

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