CN116355808B

CN116355808B - Bacillus aerophilus and application thereof

Info

Publication number: CN116355808B
Application number: CN202310414585.0A
Authority: CN
Inventors: 黄玉兰; 曹正林; 李有真; 丁红霞
Original assignee: Heilongjiang Bayi Agricultural University
Current assignee: Heilongjiang Bayi Agricultural University
Priority date: 2023-04-18
Filing date: 2023-04-18
Publication date: 2024-02-20
Anticipated expiration: 2043-04-18
Also published as: CN116355808A

Abstract

The invention discloses bacillus acidophilus and application thereof, and belongs to the field of microorganisms. The preservation number of the bacillus acidophilus (Bacillus aerophilus) is CCTCC NO: m20221773. The strain was isolated from the soil of the stock seed field red peony seedling base in the city of Anda, heilongjiang, and classified as Bacillus genus (Bacillus sp.) based on physiological and biochemical characteristics and 16S rDNA analysis. The growth promoting function identification result shows that the strain CS14 has the capability of producing nitrogen fixation, producing siderophores, producing ACC deaminase and producing indoleacetic acid (IAA); the germination test result shows that the strain can obviously promote the germination of red paeony root seeds and the growth of hypocotyls under the stress of saline alkali. Therefore, the invention provides excellent growth promoting strain resources for the germination and growth of the red paeony root seeds, and lays a foundation for the development of biological preparation products for biological treatment of the saline-alkali soil.

Description

Bacillus aerophilus and application thereof

Technical Field

The invention relates to the field of microorganisms, in particular to bacillus acidophilus and application thereof.

Background

Soil salinization is an environmental problem worldwide, with 3.8 hundred million hm worldwide ² Saline-alkali soil and saline-alkali soil of China reach 9913 ten thousand hectares, and the saline-alkali soil area of the world is 10.4%, and the third place of the world is high. The distribution of the saline-alkali soil in China comprises 17 provinces including northwest, northeast, north China and coastal areas, and the total area of the saline-alkali soil affecting the cultivated land exceeds 5 hundred million mu. Soil salinization severely restricts the development of the global agriculture and animal husbandry, especially in arid and semiarid regions, and is one of the problems to be solved currently. In recent years, with the increase of agricultural planting years and influence factors such as environment and unreasonable cultivation modes, a large amount of salt is in soilIs accumulated in the cultivated layer, causes soil salinization, and is a serious threat to the effective utilization of the world land resources.

Radix Paeoniae Rubra (Paeoniae Rubra Radix) is dried root of Paeonia lactiflora Pallas or Paeonia suffruticosa (Paeonia lactiflora) of Ranunculaceae. It has bitter taste, slightly cold nature, and liver meridian entered property, and has the effects of clearing heat and cooling blood, removing blood stasis and easing pain. The active chemical components and the medicinal value of the composition are widely applied to medical, chemical and pharmacological researches, and the composition has certain intervention effect on the nervous system and the endocrine system, and has the effects of anti-inflammatory, antibacterial, anti-tumor, antioxidant, antidepressant, immunity regulating and the like. The radix paeoniae rubra has important pharmacological effects because of wide and obvious pharmacological effects, plays an important role in medicinal material market circulation and hospital pharmacy application, and is advocated by people in the world of Chinese medicine. The red paeony root has long history of application, large dosage, wide application and considerable annual export quantity. In recent years, wild red paeony root resources are gradually decreased year by year, artificially planted red paeony roots become a development trend, seed propagation and seedling transplantation are often adopted in red paeony root cultivation production, but the deep dormancy characteristic of red paeony root seeds in long-term natural system evolution severely limits the working processes of red paeony root propagation, cultivation and breeding.

Plant rhizosphere growth promoting bacteria (Plant Growth Promoting Rhizobacteria, PGPR) are a class of bacteria that colonize plant rhizosphere and are capable of inducing systemic resistance of plants to biotic and abiotic stress by means of nitrogen fixation, ammonia production, phosphorus dissolution and essential nutrients, phytohormone production, ACC deaminase production, and pathogenic microorganism inhibition. A large number of researches show that the rhizosphere beneficial microorganism has the capability of enhancing the abiotic stress tolerance of plants such as drought stress, saline-alkali stress, heavy metal stress, nutrient deficiency and the like in the aspect of coping with the abiotic stress.

Zhang Fuhai, and the like, the yield and the quality of the medlar in a saline-alkali environment can be obviously improved after the saline-alkali resistant growth promoting microbial inoculum is applied, and the growth, the leaf chlorophyll content, the yield, the hundred-grain weight and the fruit polysaccharide content of the medlar branches are obviously increased; pang Xuebing and the like show that the strain with ACC deaminase activity can effectively relieve the inhibition effect of saline-alkali stress on the growth of cotton seedlings and improve the resistance of the cotton seedlings to the saline-alkali stress. However, no report on germination and growth promotion of the Paeonia strain is found at present.

Disclosure of Invention

The invention aims to provide the bacillus acidophilus and the application thereof, so as to solve the problems in the prior art, and the strain has the capabilities of producing nitrogen and iron carrier, producing ACC deaminase and producing indoleacetic acid, and can obviously promote the germination of red paeony root seeds and the growth of hypocotyls under the stress of saline alkali.

In order to achieve the above object, the present invention provides the following solutions:

the invention provides a Bacillus acidophilus, which is named as Bacillus acidophilus CS14, latin is Bacillus sp.CS14, and the preservation number of the Bacillus acidophilus is CCTCC NO: m20221773, the preservation unit is China center for type culture Collection, the preservation address is the university of Wuhan, post code 430072, and the preservation date is 2022, 11 months and 11 days.

The invention also provides a microbial agent or microbial fertilizer, which comprises the bacillus acidophilus.

The invention also provides an application of the bacillus aerophilus or the microbial preparation in promoting germination and growth of plant seeds.

Preferably, the plant comprises red peony.

Preferably, the method is applied to the promotion of the germination of red paeony seeds and the growth of hypocotyls.

The invention also provides an application of the bacillus acidophilus in preparing a preparation for inhibiting the generation of 1-aminocyclopropane-1-carboxylic acid, promoting the synthesis of indoleacetic acid, promoting the synthesis of siderophores or fixing nitrogen of plants.

The invention also provides application of the bacillus acidophilus in preparing a microbial agent or microbial fertilizer for promoting germination and growth of plant seeds.

Preferably, the microbial agent or microbial fertilizer comprises the bacillus acidophilus, and the microbial agent or microbial fertilizer promotes germination of plant seeds and growth of hypocotyls.

Preferably, the plant comprises red peony.

The invention discloses the following technical effects:

the bacillus CS14 separated and screened from the salinized soil can synthesize ACC deaminase in cells, and can grow by taking ACC as a unique nitrogen source and decompose the ACC; can synthesize IAA and siderophore, and has nitrogen fixation function. The bacillus CS14 is utilized to treat red paeony root seeds under the saline-alkali stress, and germination results show that: the microbial inoculum can obviously promote the germination of red paeony root seeds and the growth of hypocotyls. Therefore, the invention provides excellent growth promoting strain resources for the germination and growth of the red paeony root seeds, and lays a foundation for the development of biological preparation products for biological treatment of the saline-alkali soil.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings that are needed in the embodiments will be briefly described below, and it is obvious that the drawings in the following description are only some embodiments of the present invention, and other drawings may be obtained according to these drawings without inventive effort for a person skilled in the art.

FIG. 1 is a phylogenetic tree of strain CS14 16S rDNA;

FIG. 2 is the effect of strain CS14 treatment on the germination phenotype of red peony seeds under saline-alkali stress;

FIG. 3 shows the effect of different concentrations of strain CS14 treatment on radix Paeoniae Rubra seed germination under saline-alkali stress; a: germination rate; b: germination vigor; c: germination index; d: a vitality index;

FIG. 4 shows the effect of strain CS14 on radix Paeoniae Rubra seed germination under saline-alkali stress at different treatment times; a: germination rate; b: germination vigor; c: germination index; d: a vitality index;

FIG. 5 is a graph showing the effect of different treatment groups on the activity of red peony seed amylase and G-CPDH enzyme under saline-alkali stress;

FIG. 6 is the effect on red peony seed hypocotyl after treatment with strain CS 14;

FIG. 7 is a statistical plot of the effect on the hypocotyl of red peony seed after treatment with strain CS14.

Detailed Description

Various exemplary embodiments of the invention will now be described in detail, which should not be considered as limiting the invention, but rather as more detailed descriptions of certain aspects, features and embodiments of the invention.

It is to be understood that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. In addition, for numerical ranges in this disclosure, it is understood that each intermediate value between the upper and lower limits of the ranges is also specifically disclosed. Every smaller range between any stated value or stated range, and any other stated value or intermediate value within the stated range, is also encompassed within the invention. The upper and lower limits of these smaller ranges may independently be included or excluded in the range.

Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. Although only preferred methods and materials are described herein, any methods and materials similar or equivalent to those described herein can be used in the practice or testing of the present invention. All documents mentioned in this specification are incorporated by reference for the purpose of disclosing and describing the methods and/or materials associated with the documents. In case of conflict with any incorporated document, the present specification will control.

It will be apparent to those skilled in the art that various modifications and variations can be made in the specific embodiments of the invention described herein without departing from the scope or spirit of the invention. Other embodiments will be apparent to those skilled in the art from consideration of the specification of the present invention. The specification and examples of the present invention are exemplary only.

As used herein, the terms "comprising," "including," "having," "containing," and the like are intended to be inclusive and mean an inclusion, but not limited to.

Example 1 isolation and identification of strains

1. Screening method of bacterial strain

2022, 9, from Anda area red peony rootMixing the newly collected radix Paeoniae Rubra rhizosphere saline-alkali soil, weighing 10g of soil sample, pouring into a triangular flask containing 90mL of sterile water, oscillating at 28deg.C for 20min, and preparing into 10 ^-3 The dilution liquid is coated on an improved S-G culture medium (the improved S-G culture medium comprises the following components of 30G/L of sodium chloride, 10G/L of yeast extract, 5.3G/L of sodium carbonate, 8.4G/L of sodium bicarbonate, 3G/L of trisodium citrate, 2G/L of potassium chloride, 1G/L of magnesium sulfate heptahydrate, 0.05G/L of ferrous sulfate heptahydrate, 0.0036G/L of manganese dichloride tetrahydrate, 20G/L of agar and 9.5) and cultured for one week at 28 ℃. And selecting colonies with different colony morphologies, purifying, passaging the purified strains for 3 times, and preserving the strain with 50% glycerol at-40 ℃ for later use.

2. Bacterial strain screening method with growth promoting function

The separated strains are respectively inoculated on an Abrus calamus Bei Modan culture medium, an ADF culture medium and a CAS culture medium and are cultured for 7 days at 28 ℃, and the strains can grow on the Abrus calamus Bei Modan culture medium or the ADF culture medium and are considered to have the functions of nitrogen fixation or ACC deaminase production; can grow on CAS medium and can produce orange-colored halos, which are considered siderophore-producing functions. The strain is inoculated in King culture medium containing 100mg/mL tryptophan, shake culture is carried out at 28 ℃ and 175rpm for 24 hours, supernatant and Salkowski colorimetric solution are centrifugally taken and mixed on a white porcelain plate in equal quantity, after being placed in dark for 30 minutes, the color development condition is observed, 3 repeats are arranged for each sample, and blank control is the mixed solution of the culture medium without bacteria and the colorimetric agent, and the IAA can be produced through color development reaction.

Culture medium used in the above experimental procedure:

(1) The Leptoradix Itis Cannabifoliae Bei Modan culture medium comprises the following components: potassium dihydrogen phosphate 0.2g/L, sodium chloride 0.2g/L, magnesium sulfate heptahydrate 0.5g/L, calcium sulfate 0.2g/L, potassium sulfate dihydrate 0.2g/L, calcium carbonate 5g/L, glucose 10g/L, agar 20g/L, and pH 7.0.

(2) ADF medium included the following components: 4.0g/L of potassium dihydrogen phosphate, 6.0g/L of disodium hydrogen phosphate, 0.2g/L of magnesium sulfate heptahydrate, 0.1g/L of ferrous sulfate heptahydrate, 2.0g/L of glucose, 2.0g/L of gluconic acid, 2.0g/L of citric acid, 3.0mmol/L of ACC and 0.1mL/L of trace elements, and the pH value is 7.5; the microelements comprise the following components: boric acid 100mg/L, magnesium sulfate heptahydrate 112mg/L, zinc sulfate 1.246g/L, copper sulfate pentahydrate 782mg/L, and molybdenum trioxide 100mg/L.

(3) CAS medium:

(1) dissolving 0.024g of chrome azurin in 20mL of double distilled water, and uniformly mixing with 4mL of 1mmol/L ferric trichloride solution to obtain a solution a;

(2) 0.030g of cetyl trimethyl ammonium bromide is taken and dissolved in 16mL of double distilled water, and a solution b is obtained; slowly adding the solution a into the solution b along the bottle wall, and fully and uniformly mixing to obtain a dye solution c;

(3) 10 XMM 9 salt solution: 30g of disodium hydrogen phosphate, 1.5g of monopotassium phosphate, 2.5g of sodium chloride, 5g of ammonium chloride and 500mL of double distilled water;

(4) adding 10 XMM 9 salt solution into 150mL double distilled water, uniformly mixing, adjusting the pH to 6.8 with 1M sodium hydroxide solution, and then adding 9g of agar powder to obtain a culture medium d;

(5) respectively placing the culture medium d, the dye liquor c, 1mmol/L calcium chloride, 1mmol/L magnesium sulfate, 20% glucose solution and 10% casein amino acid solution into a sterilizing pot for sterilization (121 ℃ for 20 min), and then preserving heat for later use in a water bath pot at 50 ℃;

and respectively measuring 0.4mL of 1mmol/L calcium chloride, 8mL of 1mmol/L magnesium sulfate, 4mL of 20% glucose solution and 12mL of 10% casein amino acid solution, slowly adding the dye solution c along the bottle wall, and fully shaking uniformly to obtain the blue qualitative detection culture medium.

(4) King/L medium: hydrolyzed peptone 20g/L, dipotassium hydrogen phosphate 1.5g/L, magnesium sulfate heptahydrate 1.5g/L and glycerol 10mL/L, pH 7.2.

3. A strain of bacteria, designated CS14, was finally obtained by the two above-described screens. Bacterial strain CS14 has yellow bacterial colony on the modified S-G culture medium plate, round shape, raised surface, irregular edge, wet and smooth bacterial colony surface and luster; the bacteria are rod-shaped, gram-positive bacteria and facultative anaerobic. Physical and chemical characterization results show that beta-methyl D-glucoside, D-xylose, D-mannitol, N-acetyl-D-glucosamine, D-cellobiose, D, L-alpha-glycerol, methyl pyruvate, alpha-hydroxybutyrate, alpha-butanoic acid, D-malic acid, L-arginine, L-asparagine, L-phenylalanine, L-serine, L-threonine, glycyl-L-glutamic acid, tween 40, tween 80, 4-hydroxybenzoic acid, liver sugar, putrescine can be used as the sole carbon source or nitrogen source.

The 16S r DNA sequences were aligned with sequences in the EZ BioCloud database. Phylogenetic tree analysis of the strain 16S rDNA sequence construction showed that the similarity of the strain Bacillus CS14 Bacillus aerophilus was 99.18%. In combination with morphological and physicochemical characteristics of the strain and with 16S r DNA sequence analysis, this strain CS14 was initially identified as Bacillus aerophilus (see FIG. 1).

The 16S r DNA sequence is as follows:

GTTATCAGGCGGACGGGTGAGTAACACGTGGGTAACCTGCCTGTAAGACTGGGATAACT

CCGGGAAACCGGAGCTAATACCGGATAGTTCCTTGAACCGCATGGTTCAAGGATGAAAG

ACGGTTTCGGCTGTCACTTACAGATGGACCCGCGGCGCATTAGCTAGTTGGTGAGGTAA

CGGCTCACCAAGGCGACGATGCGTAGCCGACCTGAGAGGGTGATCGGCCACACTGGGA

CTGAGACACGGCCCAGACTCCTACGGGAGGCAGCAGTAGGGAATCTTCCGCAATGGAC

GAAAGTCTGACGGAGCAACGCCGCGTGAGTGATGAAGGTTTTCGGATCGTAAAGCTCT

GTTGTTAGGGAAGAACAAGTGCAAGAGTAACTGCTTGCACCTTGACGGTACCTAACCA

GAAAGCCACGGCTAACTACGTGCCAGCAGCCGCGGTAATACGTAGGTGGCAAGCGTTG

TCCGGAATTATTGGGCGTAAAGGGCTCGCAGGCGGTTTCTTAAGTCTGATGTGAAAGCC

CCCGGCTCAACCGGGGAGGGTCATTGGAAACTGGGAAACTTGAGTGCAGAAGAGGAG

AGTGGAATTCCACGTGTAGCGGTGAAATGCGTAGAGATGTGGAGGAACACCAGTGGCG

AAGGCGACTCTCTGGTCTGTAACTGACGCTGAGGAGCGAAAGCGTGGGGAGCGAACAG

GATTAGATACCCTGGTAGTCCACGCCGTAAACGATGAGTGCTAAGTGTTAGGGGGTTTCC

GCCCCTTAGTGCTGCAGCTAACGCATTAAGCACTCCGCCTGGGGAGTACGGTCGCAAGA

CTGAAACTCAAAGGAATTGACGGGGGCCCGCACAAGCGGTGGAGCATGTGGTTTAATT

CGAAGCAACGCGAAGAACCTTACCAGGTCTTGACATCCTCTGACAACCCTAGAGATAGG

GCTTTCCCTTCGGGGACAGAGTGACAGGTGGTGCATGGTTGTCGTCAGCTCGTGTCGTG

AGATGTTGGGTTAAGTCCCGCAACGAGCGCAACCCTTGATCTTAGTTGCCAGCATTCAG

TTGGGCACTCTAAGGTGACTGCCGGTGACAAACCGGAGGAAGGTGGGGATGACGTCAA

ATCATCATGCCCCTTATGACCTGGGCTACACACGTGCTACAATGGACAGAACAAAGGGC

TGCGAGACCGCAAGGTTTAGCCAATCCCACAAATCTGTTCTCAGTTCGGATCGCAGTCT

GCAACTCGACTGCGTGAAGCTGGAATCGCTAGTAATCGCGGATCAGCATGCCGCGGTGA

ATACGTTCCCGGGCCTTGTACACACCGCC。

in addition, the results showed that: the strain CS14 can synthesize ACC (1-aminocyclopropane-1-carboxylic acid) deaminase, can grow by taking ACC as a sole nitrogen source, and can decompose ACC generated in plants, so that the ethylene content generated in the plants due to environmental stress is reduced, and the stress resistance of the plants is enhanced. The mechanism is that ACC is a direct precursor for synthesizing ethylene in plants, and environmental stress can cause a large amount of ethylene to be generated and accumulated in the plants, and high-level ethylene can inhibit the growth of plant root systems, thereby affecting the growth and development of plants. ACC deaminase is an exogenous biomass capable of effectively reducing the content of adversity ethylene, and can obviously improve the stress resistance of crops and increase the yield under adversity conditions such as drought, salt stress, heavy metal pollution and the like.

Strain CS14 was able to produce 11.4mg/mL IAA when cultured in liquid King medium for 24 h. The strain CS14 can synthesize plant growth hormone indoleacetic acid (IAA) by taking tryptophan as a precursor, and can be directly utilized by plants due to the fact that the strain CS14 is adsorbed on the surfaces of seeds and root systems, and simultaneously can also stimulate the growth and proliferation of plant cells by coaction with IAA which is generated in the plants, so that the growth and development of the plant root systems are promoted, and moisture and nutrients in soil are effectively absorbed. And may also be involved in the regulation of other vital activities in the plant.

Strain CS14 is capable of affecting the uptake of ferric ions by plants by producing and secreting siderophores having a high affinity for iron, as siderophores are a low molecular weight organic compound capable of complexing ferric ions with high efficiency produced by microorganisms and some crops under low iron stress conditions. The strain CS14 of the invention dissolves and combines iron elements in soil for plant cells to use by producing and secreting siderophores, increases iron nutrition and promotes plant growth.

The strain CS14 is named as Bacillus sp.CS14 and is preserved in China center for type culture Collection, and the preservation address is China, university of Wuhan, and mail code 430072, and the preservation number is CCTCC NO: m20221773, the preservation date is 2022, 11 and 11.

Example 2 Effect of Strain CS14 on radix Paeoniae Rubra seed germination under saline-alkali stress

Selecting full red peony seeds, washing with clear water for 2h, sterilizing with 0.1% sodium hypochlorite for 30min, washing for 10min, soaking in water for 24h, directly placing the sterilized seeds into an aluminum box, stirring and mixing uniformly, and culturing each layer of seeds in darkness at 25+/-2 ℃ for 1 month at 20 cm from the edge of the sand layer.

Inoculating the strain into a basic culture medium LB culture medium, shaking and culturing for 24h at the temperature of 28 ℃ and the speed of 175rpm, centrifuging for 10min, washing with sterile water for three times, adjusting OD600 to 0.6, 0.7, 0.8, 0.9 and 1.0 after re-suspension, mixing sodium carbonate and sodium bicarbonate 1:10 to prepare Salt lye (SA), uniformly applying 50mL of Salt lye into wet sand, uniformly stirring 50mL of CS14 bacterial liquid with the wet sand in the seed germination test, treating once every 10 days, continuously treating for 3 times, and culturing for 30d in the dark at the temperature of 25+/-2 ℃, counting the germination rate, germination potential, germination index and activity index of red paeony root seeds in each treatment group (germination rate=number of germination seeds/number of test seeds×100%, germination potential/number of test seeds×100%, germination index of germination on the day=number of germination/germination index on the day+number of germination on the day, sequentially adding, activity index=root growth quantity×100%, physiological method of germination index on the day× Gao Junfeng%, and measuring the glucose dehydrogenase content in each treatment group.

As can be seen from FIG. 2, the embryo treated with strain CS14 developed into hypocotyl, and the cotyledon developed further and endosperm decreased. As can be seen from fig. 3, the seed germination rate showed a tendency to increase and then decrease with increasing concentration of CS14, and reached a maximum at an OD value of 0.7. Therefore, when the OD value of the strain is 0.7, the strain CS14 with the concentration has good promotion effect on the germination of the red paeony root seeds. After the red paeony root seed is treated by the strain CS14 under the saline-alkali stress shown in the figure 4, the germination rate, the germination potential, the germination index and the activity index of the seed are respectively improved by 26.80 percent, 30.50 percent, 26.82 percent and 57.78 percent compared with those of an untreated group, and the germination rate, the germination potential, the germination index and the activity index of the seed are respectively improved by 40.52 percent, 43.48 percent, 40.52 percent and 70.08 percent compared with the untreated group. As can be seen from FIG. 5, the amylase and G-CPDH enzyme activities of the red peony seeds after the strain CS14 treatment were improved by 11.95% and 22.33% respectively compared with those of the untreated group, which means that the amylase and G-CPDH enzyme activities after the strain CS14 treatment were improved, and the germination of the seeds was promoted.

Example 3 Effect of Strain CS14 on the germination of Red peony seed hypocotyls under saline-alkali stress

Inoculating the strain into basic culture medium, shake culturing at 28deg.C and 175rpm for 24 hr, centrifuging at 12000g for 10min, washing with sterile water for three times, and adjusting OD after resuspension ₆₀₀ To 0.6, 0.7, 0.8, 0.9 and 1.0, 50mL of CS14 bacterial liquid is uniformly stirred with wet sand in the seed germination test, the seed germination test is treated once every 10 days, the seed germination test is continuously treated for 3 times, and after dark culture for 30 days at 25+/-2 ℃, the hypocotyl length of the red peony seed of each treatment group is counted.

As can be seen from fig. 6 and 7, the strain CS14 significantly increased the hypocotyl length of the red peony seed after treatment, and a significant difference occurred compared to the saline-alkali stress group, whose hypocotyl length was 55.58% higher than that of the SA stress group.

The above embodiments are only illustrative of the preferred embodiments of the present invention and are not intended to limit the scope of the present invention, and various modifications and improvements made by those skilled in the art to the technical solutions of the present invention should fall within the protection scope defined by the claims of the present invention without departing from the design spirit of the present invention.

Claims

1. Bacillus acidophilusBacillus aerophilus) The method is characterized in that the bacterial preservation number is CCTCC NO: m20221773.

2. A microbial inoculant or microbial fertiliser comprising the bacillus aerophilus of claim 1.

3. Use of the bacillus aerophilus of claim 1 or the microbial agent of claim 2 for promoting germination and growth of red peony seeds.

4. The use according to claim 3, for promoting germination of red peony seeds and growth of hypocotyls.

5. Use of the bacillus acidophilus of claim 1 for preparing a preparation for inhibiting the production of 1-aminocyclopropane-1-carboxylic acid, promoting the synthesis of indoleacetic acid, promoting the synthesis of siderophores or for nitrogen fixation of plants.

6. Use of the bacillus acidophilus of claim 1 in the preparation of a microbial agent or microbial fertilizer for promoting germination and growth of red peony seeds.

7. The use of claim 6, wherein said microbial agent or microbial fertilizer comprises said bacillus acidophilus, said microbial agent or microbial fertilizer promoting germination of red peony seeds and growth of hypocotyls.