CN111100816B

CN111100816B - Spherical lysine bacillus SY50 and application thereof

Info

Publication number: CN111100816B
Application number: CN202010024052.8A
Authority: CN
Inventors: 王秀艳; 邢明振; 张云鸽; 郭岩彬; 王淑平
Original assignee: Genliduo Bio Tech Corp ltd
Current assignee: Xinjiang Genliduo Biotechnology Co ltd
Priority date: 2020-01-09
Filing date: 2020-01-09
Publication date: 2022-04-22
Anticipated expiration: 2040-01-09
Also published as: CN111100816A

Abstract

The invention discloses spherical lysine bacillus SY50 and application thereof. The preservation number of the strain SY50 is CCTCC NO: m2019841 and SY50 strain can dissolve inorganic phosphorus and organic phosphorus in a large amount and can also produce IAA, protease, cellulase, siderophin and other growth promoting substances. Taking corn as an example, the strain SY50 has obvious plant growth promoting effect, and can increase the stem height of corn seedlings by 32.49%, the fresh stem weight by 39.43%, the stem weight by 32.69%, the root fresh weight by 32.49% and the root dry weight by 30.36%. The strain SY50 can be applied to crop planting to improve crop yield, improve the resistance of plants to diseases, drought and other stresses, and has important significance for continuous grain yield increase and farmland ecological environment protection in China.

Description

Spherical lysine bacillus SY50 and application thereof

Technical Field

The invention relates to agricultural microbiology, in particular to a spherical lysine bacillus SY50 and application thereof.

Background

The plants always keep the symbiotic relationship with soil microorganisms in the growth and development process. Symbiotic soil microorganisms live around the rhizosphere of many different plants, have many beneficial effects on host plants, and competitively colonize plant roots through different mechanisms of action to promote plant growth including phosphate solubilization, nitrogen fixation, indole-3-acetic acid (IAA) production, siderophore production, 1-aminocyclopropane-1-carboxylic Acid (ACC) deaminase and hydrogen cyanide; degrading environmental pollutants, producing hormones, antibiotics, cytolytic enzymes, and the like. In addition, some PGPR may also promote plant growth by other means such as inactivation of heavy metals, promotion of plant salt tolerance, control of plant pathogens and insects, and the like.

In the safety classification catalogue of strains of the lysinibacillus sphaericus in rural agricultural departments, some existing reports in agricultural aspects mainly degrade pesticide residues (Tengchun et al, 2013; Lemna minor, etc., 2014), and antagonize pathogenic bacteria (having an shining in the land, etc., 2014); there are other applications, such as mediating the ability to form dolomite, controlling ethyl carbamate in white spirit, etc. No research report on the aspects of promoting plant growth, dissolving insoluble phosphorus and producing enzyme is found, and the invention has important significance for the application of the spherical lysine bacillus in agriculture.

Disclosure of Invention

The invention aims to provide a spherical lysine bacillus SY50 strain and application thereof.

In order to achieve the purpose of the invention, in the first aspect, the invention provides a salt-tolerant spherical lysine bacillus SY50 (lysine bacillus sphaericus SY50) separated from soil collected from experimental demonstration bases of root force multi-biotechnology, Inc. of Wei county, N.C. of chentai, Hebei, wherein the strain SY50 can not only dissolve a large amount of insoluble inorganic phosphorus and organic phosphorus, but also can produce a plurality of other growth-promoting substances, including auxin (IAA), cellulase, protease, siderophagin and the like. The strain is preserved in China center for type culture Collection at the address: wuhan, Wuhan university, zip code 430072, preservation number CCTCC NO: m2019841, date of deposit 2019, 10 months and 21 days.

In a second aspect, the invention provides a microbial inoculum containing the spherical lysine bacillus SY 50.

In a third aspect, the invention provides a growth promoting substance secreted by the spherical lysine bacillus SY50, such as IAA and the like.

In a fourth aspect, the invention provides enzymes secreted by the spherical lysine bacillus SY50, wherein the enzymes include but are not limited to cellulase and protease.

In a fifth aspect, the invention provides siderophins secreted and produced by the spherical lysine bacillus SY50,

in a sixth aspect, the invention provides an agricultural fertilizer, a phosphorus activator, a plant growth promoter, a heavy metal pollution degradation agent or an iron chelating agent prepared from the spherical lysine bacillus SY50 or a microbial inoculum thereof.

In a seventh aspect, the invention provides any one of the following applications of the spherical lysine bacillus SY50 or a microbial inoculum thereof:

1) for promoting plant growth and development and increasing crop yield;

2) the plant stress resistance is improved;

3) dissolving phosphorus;

4) the method is used for repairing heavy metal pollution;

5) the method is used for preparing agricultural fertilizers;

6) used for preparing a phosphorus activator;

7) for the preparation of plant growth promoters;

8) used for preparing heavy metal pollution degradation agent;

9) used for preparing iron chelating agent.

Plants described in the present invention include, but are not limited to, corn, wheat, soybean, cucumber.

The heavy metal comprises iron.

The improvement of the stress resistance of the plants refers to the improvement of the stress resistance of the plants such as disease resistance, drought resistance, heavy metal poison resistance and the like.

In an eighth aspect, the invention provides application of the spherical lysine bacillus SY50 or a microbial inoculum thereof in dissolving insoluble phosphorus.

For the above applications, the insoluble phosphorus includes insoluble inorganic phosphorus (such as calcium phosphate) and insoluble organic phosphorus (such as calcium phytate and lecithin).

By the technical scheme, the invention at least has the following advantages and beneficial effects:

the salt-tolerant spherical lysine bacillus SY50 provided by the invention can dissolve a large amount of insoluble inorganic phosphorus and organic phosphorus, and can also generate various growth promoting substances such as IAA, protease, cellulase, siderophin and the like. Taking corn (Zhengdan 958) as an example, the strain SY50 has obvious effect of promoting the growth of plants, and can increase the stem height of corn seedlings by 32.49%, the fresh weight of stems by 39.43%, the weight of stems by 32.69%, the fresh weight of roots by 32.49% and the dry weight of roots by 30.36%. The strain SY50 can be applied to crop planting to improve crop yield, improve the resistance of plants to diseases, drought and other stresses, and has important significance for continuous grain yield increase and farmland ecological environment protection in China.

Drawings

FIG. 1 shows the result of the measurement of the phosphorus-solubilizing ability of the strain SY50 in example 2 of the present invention (inorganic phosphorus solubilizing ring).

FIG. 2 shows the result of determination of the phosphorus-solubilizing ability of the strain SY50 in example 2 of the present invention (organophosphorus solubilizing ring).

FIG. 3 shows the results of the determination of the protease-producing capacity of the strain SY50 in example 3 of the present invention.

FIG. 4 shows the result of the determination of the cellulase producing ability of the strain SY50 in example 5 of the present invention.

FIG. 5 shows the result of the measurement of the siderophore productivity of the strain SY50 in example 6 of the present invention.

FIG. 6 shows the plant growth promoting effect of the strain SY50 in example 8 of the present invention.

FIG. 7 shows a molecular evolutionary tree of the 16S rRNA gene of strain SY50 in example 1 of the present invention.

Detailed Description

The following examples are intended to illustrate the invention but are not intended to limit the scope of the invention. Unless otherwise specified, the technical means used in the examples are conventional means well known to those skilled in the art, and the raw materials used are commercially available products.

Example 1 isolation and characterization of Strain SY50

Collecting soil from experiment demonstration base of Genli Multi-Biotechnology, Inc. of Wei county, Cheng Tai, Hebei, taking 10g of soil sample, adding into a triangular flask filled with 100ml of sterile physiological saline, standing for 20min, shaking for 30min at 28 ℃, 200rpm in a shaking table, taking 1ml of sample, adding into 9ml of sterile physiological saline, sequentially diluting for 10²，10³，10⁴Taking the above soil suspension 1 respectivelyAnd (2) uniformly coating 00 mu L of the strain on an LB culture medium (5 g/L of yeast powder, 10g/L of peptone, 10g/L of NaCl and 15g/L of agar) plate, culturing for 48h in an incubator at 28 ℃, picking out a bacterial single colony by using a sterile toothpick, streaking and purifying, and storing for later use.

The strain SY50 is identified as lysine bacillus sphaericus (Lysinibacillus sphaericus) by combining the physiological and biochemical characteristics and the molecular biological detection result. The specific identification results are as follows:

1. molecular biological identification

The strain SY50 was first identified molecularly using primer 27F: 5'-AGAGTTTGATCCTGGTCAGAACGAACGCT-3' and 1492R: 5 '-TACGGCTACCTTGTTACGACTTCACCCC-3' amplifying the 16S rRNA gene sequence, sequencing and obtaining the sequence shown in SEQ ID NO: 1 is shown.

The PCR reaction system is as follows: 2 XTaq Mix 12.5. mu.l, primers 27F, 1492R each 1. mu.l, DNA template 1. mu.l, ddH₂O9.5. mu.l. The PCR reaction conditions are as follows: pre-denaturation at 94 ℃ for 5 min; denaturation at 94 ℃ for 30s, annealing at 56 ℃ for 30s, extension at 72 ℃ for 1min, and 30 cycles; extension at 72 ℃ for 5 min. Among them, Taq Mix was purchased from TaKaRa.

The PCR amplification product was analyzed by 1% agarose Gel electrophoresis, purified and recovered with Gel Extraction Kit from OMEGA, and ligated with T vector pMD18-T from TaKaRa. Sequencing by using an ABI 3730DNA sequencer, submitting the gene sequence to GenBank, and recording the number: MN 559041. The sequence was subjected to molecular tree analysis with GEGA5 (fig. 7), and SY50 was preliminarily judged as lysergic globulosa according to the tree.

2. Physiological and biochemical characteristic identification

On the basis of molecular biological detection, carrying out physiological and biochemical identification on the strain SY50, firstly carrying out gram staining on the strain SY50, and displaying the result that the strain is gram positive; after being activated, the strain is inoculated into an LB culture medium with NaCl concentration of 7 percent and cultured for 48 hours at 28 ℃, and as a result, no strain grows; a piece of filter paper was placed in a clean petri dish, and a 1% aqueous solution of dimethyl-p-phenylene diamine was added dropwise to wet only the filter paper. Selecting a ring of thallus Porphyrae with platinum loop, and spreading on wet filter paper. The applied lawn appeared red within 10 seconds, indicating the bacteriaSY50 positive oxidase; activating the bacteria, inoculating the bacteria in a nitrate liquid culture medium, culturing for 1, 3 and 5 days at 30 ℃, pouring a little culture solution into small holes of a white magnetic disk, and then respectively dripping 1 drop of a reagent A (0.5 g of sulfanilic acid is dissolved in 150mL of 10% acetic acid) and a reagent B (0.1 g of alpha-naphthylacetic acid is dissolved in 20mL of distilled water and 150mL of 10% acetic acid) into the small holes, wherein the result shows that the culture solution is not discolored, which indicates that the nitrate reduction of a strain SY50 is negative; inoculating the strain into gelatin culture, culturing at 20 deg.C for 7 days, and thawing the culture medium to show positive hydrolysis of gelatin; picking single colony with gun head, placing on glass slide, adding one drop of 3% H₂O₂The solution is on the bacterial colony, and bubbles appear, which indicates that the bacterial strain is positive in catalase; activating the strain and then inoculating the strain to a bacillus sugar fermentation culture medium, wherein the test result shows that the strain SY50 can not utilize sucrose and D-xylose for fermentation to produce acid; SY50 was inoculated into methyl red medium (peptone 5g, glucose 5g, sodium chloride 5g, distilled water 1000ml, pH7.0-7.2) and cultured at 30 ℃ for 1-2 days. A few drops of methyl red reagent are added into the culture medium, if the culture solution is red, the culture solution is positive to methyl red, and yellow is negative. The test results show that the strain SY50 is m.r. negative; acetylmethylmethanol (VP test) medium, inoculation and seed culture are the same as methyl Red test. In the VP test, the culture medium (about 2ml) is mixed with 40% NaOH, a small amount of creatine is added, and the mixture is sufficiently shaken for 2-5min, if the culture medium is red, the VP is positive. The test result shows that the strain SY50 is VP negative; the activated strain is inoculated in LB solid slant culture medium added with 0.1 percent of esculin and 0.5 percent of ferric citrate, and the strain is cultured at a proper temperature for 3, 7 and 14 days to be observed, and the strain is positive when producing black brown pigment and negative when not producing black brown pigment. The results of the hydrolysis esculin test show that the strain SY50 is negative; hydrogen sulfide generation test: preparing a test tube slant culture medium (10 g of peptone, 0.1g of cystine, 0.1g of sodium sulfate, 1000ml of distilled water, pH7.0-7.4), cutting common filter paper into strips with the width of 0.5-1cm, soaking the filter paper with 5% -10% lead acetate, and then drying the filter paper by using an oven. Inoculating the activated strain to test tube slant, clamping a filter paper strip with aseptic forceps, tightening with cotton plug to hang in the test tube, allowing the lower end to approach the surface of the culture medium without contacting the liquid surface, culturing at moderate temperature, and inoculating 3, 7, and 14 timesThe test piece was observed every day, and the test piece was positive when it became black and negative when it did not. The test results for the production of hydrogen sulfide show that the strain SY50 is negative; production of indole assay: inoculating the activated strain in a liquid culture medium containing 1% tryptone water, taking culture solution for culturing 1, 2, 4 and 7 at proper temperature, slowly adding a p-dimethylaminobenzaldehyde reagent (8 g of p-dimethylaminobenzaldehyde solution, 760ml of 95% alcohol and 160ml of concentrated hydrochloric acid) with the height of 3-5 mm on the surface of the culture solution along the tube wall, and generating red color on the interface of the liquid layer, namely obtaining a positive reaction. The indole production test results show that the strain SY50 is negative. The results of physiological and biochemical tests of the strain SY50 are shown in Table 1. SY50 can be judged as lysine bacillus sphaericus according to the evolutionary tree and physiological and biochemical results.

TABLE 1 physiological and biochemical characteristics of Bacillus sphaericus SY50

Example 2 determination of the phosphorus-solubilizing ability of Strain SY50

The strain SY50 was first activated on LB medium. The activated strain was inoculated into a phosphate-solubilizing medium (10.00 g of glucose, (NH) shown in appendix A of NY/T1847-2010)₄)₂SO₄ 0.50g，MnSO₄·7H₂O 0.3g，NaCl 0.3g，KCl 0.30g，FeSO₄·4H₂O 0.036g，MnSO₄·4H₂O0.03 g, distilled water 1000mL, pH 7.0. The inorganic phosphorus source is calcium phosphate, and the addition amount is 10 g; the organic phosphorus source is calcium phytate, and the addition amount is 2 g. Solid medium: add 1.5% agar powder in proportion). And detecting whether the strain has a phosphorus dissolving function, wherein the strain SY50 has the capacity of dissolving inorganic phosphorus and organic phosphorus simultaneously, the diameter of a dissolving ring for dissolving the inorganic phosphorus reaches 1.21cm (figure 1), and the diameter of a dissolving ring for dissolving the organic phosphorus reaches 1.52cm (figure 2). The separated other phosphate solubilizing bacteria such as Bacillus subtilis, Bacillus megaterium, etcThe capacity is not as good as that of the spherical lysine bacillus SY 50.

After the phosphorus dissolving function of the strain is determined, quantitatively measuring the phosphorus dissolving capacity of the strain, activating the strain on LB liquid culture medium, inoculating the strain on the liquid phosphorus dissolving culture medium, shaking and culturing for 7 days at 28 ℃, measuring the effective phosphorus content in fermentation supernatant by a molybdenum-antimony colorimetric resistance method, taking 100 mu L of supernatant, putting the supernatant into a 50ml volumetric flask, diluting the supernatant to about 30ml by water, adding 2 drops of a dinitrophenol indicator, dropwise adding 4mol/L NaOH solution until the solution just turns yellow, adding 1mol/L H mol₂SO₄1 drop, make the yellow color of the solution just fade away. Adding 5.00ml molybdenum-antimony color-developing resisting agent, adding water to constant volume, and shaking up thoroughly. After standing at room temperature above 15 ℃ for 30min, 200. mu.l of the mixture was added to a 96-well plate, and the absorbance was measured at a wavelength of 882nm using a microplate reader.

The result shows that the capability of the strain SY50 for dissolving inorganic phosphorus reaches 386.51mg/L, and the capability for dissolving organic phosphorus reaches 101.42 mg/L.

Example 3 determination of the ability of Strain SY50 to produce protease

The method comprises the steps of firstly activating a strain SY50 on an LB culture medium, inoculating the activated strain on a culture medium for detecting protease (5.00 g of tryptone, 3.00g of yeast extract, 1.00g of glucose, 15.00g of agar, 1000mL of distilled water, pH7.0 and 121 ℃ for 30min in an autoclave manner), cooling the sterilized detection culture medium to about 50 ℃, adding 10% of skimmed milk into the culture medium, uniformly mixing, pouring the mixture into a culture dish, cooling the culture dish for later use, culturing the culture dish at 28 ℃ for 48h, and observing whether a dissolving ring appears, wherein the result shows that SY50 has good capability of dissolving protein and high-yield protease, and the diameter of the dissolving ring reaches 4.10cm (figure 3). By utilizing the characteristic of high-yield protease of the strain SY50, the extracted protease can be applied to the protease fields of food industry or washing industry and the like, and can also be used for controlling diseases by degrading pathogenic bacteria cell membranes in agricultural microbial fertilizers and degrading proteins in agricultural wastes in composts.

Example 4 determination of IAA-producing ability of Strain SY50

Firstly, the strain SY50 is activated on LB liquid culture medium, and the amount of the activated strain is 1 percentInoculated into DF + medium (peptone 5.00g, yeast extract 1.50g, beef extract 1.50g, NaCl 5.00g, tryptophan 0.50g, distilled water 1000mL, pH7.0, high pressure steam sterilization at 121 ℃ for 30 min). Shaking at 28 deg.C for 7 days, taking out the fermentation broth after 7 days, centrifuging at 12000rpm for 5min, and determining IAA content in the fermentation broth by Salkowkin colorimetry. The result shows that the strain SY50 produces IAA in an amount of 9.72 mg/L. The strain is analyzed and confirmed to synthesize IAA by HPLC detection, after the strain is cultured for 7 days, the strain is centrifuged at 12000rpm for 5min, 30mL of supernatant is taken, two times of volume of ethyl acetate is used for fully extracting in a constant temperature oscillator for 3 times, the combined extracts are distilled by an ethyl acetate reduced pressure distiller, and then are dissolved by 5mL of methanol, the volume is constant, and the mixture is filtered by a 0.22um filter membrane. Reference literature (Liancuifei, Jiangzhi, Lihuci, Luxiouyun, chaulmoogra and Maping) utilizes high performance liquid chromatography to screen plant hormone producing bacteria [ J]North china agro-scientific newspaper 2006 (02): 66-69; high performance liquid chromatography shear wavelength method for determining endogenous hormone [ J ] in folium Artemisiae Argyi]Modern agricultural technology, 2007 (03): 9-11) for sample detection. A detection instrument: waters2998 high performance liquid chromatography, column: agilert Zorbax SB-C₁₈250mm × 4.6mm, 5 um. Mobile phase, methanol, acetonitrile, 0.6% glacial acetic acid in water (50: 5: 45 by volume). Sample introduction amount: 20 μ l. The flow rate was 0.8 mL/min. Column temperature: and (4) room temperature. Detection wavelength: 255 nm. The detection result is 9.90mg/L, which is slightly higher than the detection result of the colorimetric method.

Example 5 determination of cellulase-producing ability of Strain SY50

The strain SY50 was first activated on LB medium, and the activated strain was inoculated on a cellulose detection medium (MgSO)₄·7H₂O 0.25g，K₂HPO₄0.50g, 1.88g of carboxymethyl cellulose, 15.0g of agar, 1000mL of distilled water, pH7.0, and autoclaving at 121 ℃ for 30 min). Culturing at 28 ℃ for 7 days, adding 5mL of 0.2mg/mL Congo red dye solution into each plate after 7 days, dyeing for 1h, removing the Congo red dye solution, adding 1M NaCl, washing for 1h, removing the washing solution, observing the generation of a hydrolysis ring around a bacterial colony, wherein the generation of the hydrolysis ring indicates the generation of cellulase. The results show that SY50 has good capacity of dissolving cellulose and has a good dissolution circleThe diameter reached 5.82cm (FIG. 4). SY50 high yield cellulose can degrade pathogenic fungi cell wall, control diseases, and decompose cellulose in compost.

Example 6 measurement of Ferrophilic Activity of Strain SY50

Firstly, the strain SY50 is activated on LB culture medium, and the activated strain is inoculated in a culture medium containing CAS blue detection solution for culture (a certain amount of CAS blue detection solution is added into an iron-deficiency complex culture medium consisting of acid hydrolyzed casein and other inorganic salts to prepare a blue detection plate). If the bacteria produce siderophiles, sequestering the iron (ferric) in the medium, a yellow halo is produced around the colony. The results show that SY50 has a good ability to chelate iron. The halo diameter reaches 1.85cm (fig. 5). SY50 can enrich part of iron ions to plant root to promote absorption of iron by plant.

Example 7 preparation of microbial inoculum

1. Strain activation

The strain SY50 was first activated on LB medium. The strain SY50 is inoculated in LB liquid culture medium and cultured for 12h at 28 ℃.

2. Cultivation of seed liquid

The seed culture medium comprises the following components: 15g/L of peptone, 8g/L of yeast extract, 12g/L of glucose, 10g/L of NaCl and 7.2 of pH value. Inoculating the activated strain SY50 into a seed liquid culture medium with an inoculation amount of 1.2%, and performing shake culture at 28 deg.C with a shaker at a rotation speed of 200rpm for 12 h.

3. Fermenting in a fermentation tank

The fermentation medium comprises the following components: 12g/L of corn steep liquor, 8.5g/L of corn flour, 1.8g/L of yeast extract, 2.0g/L of peptone, 2.0g/L of glucose and KH₂PO₄ 0.6g/L，MgSO₄·7H₂O 0.06g/L，MnSO₄·7H₂O 0.018/L，CaCO₃4g/L, 1.2g/L of polyether defoamer and 7.2 of pH value. The cultured seed liquid OD₆₀₀When reaching 4.00, the mixture is inoculated into a fermentation tank according to the inoculation amount of 5 percent, the stirring speed is 180rpm at 28 ℃, and the ventilation quantity is adjusted to ensure that the dissolved oxygen is more than 60 percent and the tank pressure is 0.05 MPa. The bacterial quantity can reach 10 after fermentation for 36h¹⁰cfu/ml, spore formationStopping fermentation when the amount reaches more than 95%, cooling, placing in a tank, and optimizing the formula of the fermentation medium to obtain 10 of spherical lysine bacillus SY50¹⁰The yield of the cfu/mL bacterial liquid IAA is improved to 16.3mg/L from 9.9mg/L, and the bacterial liquid can be prepared into a solid or liquid bacterial agent according to requirements.

Example 8 plant growth promotion test of Strain SY50

The method comprises the steps of selecting plump and healthy corn (Zhengdan 958) seeds, sterilizing, cleaning, soaking, and then putting into a biochemical incubator at 28 ℃ for culture and germination acceleration for about 24 hours. Selecting single colony from a flat plate of a test strain, activating the single colony in an LB liquid culture medium, inoculating the activated bacterial liquid into the LB liquid culture medium according to the inoculation amount of 1 percent, shaking and culturing at 28 ℃, 150rpm for 72 hours, and diluting the bacterial liquid by 10⁶cfu/mL. 100ml of diluted bacterial solution was added to each pot, and each pot was made of low-phosphorus soil and 0.5% calcium phosphate was added. Meanwhile, LB culture medium is used as a blank Control (CK), and the stem height, the fresh weight of the stem, the dry weight of the stem and the dry weight of the root of the corn seedling are measured after the corn seedling grows for 30 days.

The results show that strain SY50 has a good growth promoting effect (FIG. 6). The stem height of the corn seedlings can be increased by 32.49%, the fresh weight of the stems can be increased by 39.43%, the weight of the stems can be increased by 32.69%, the fresh weight of the roots can be increased by 32.49%, and the dry weight of the roots can be increased by 30.36% (Table 2).

TABLE 2 growth promoting effect of Strain SY50 on maize

Note: the significant differences are represented by P < 0.05 and P < 0.01.

Although the invention has been described in detail hereinabove with respect to a general description and specific embodiments thereof, it will be apparent to those skilled in the art that modifications or improvements may be made thereto based on the invention. Accordingly, such modifications and improvements are intended to be within the scope of the invention as claimed.

Sequence listing

<110> Gen Lian Multi-Biotechnology Ltd

<120> spherical lysine bacillus SY50 and application thereof

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<170> SIPOSequenceListing 1.0

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<213> lysine bacillus sphaericus (lysine bacillus sphaericus)

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gagtaacacg tgggcaacct accctatagt ttgggataac tccgggaaac cggggctaat 120

accgaataat ctatttcacc tcatggtgaa atactgaaag acggtttcgg ctgtcgctat 180

aggatgggcc cgcggcgcat tagctagttg gtgaggtaat ggctcaccaa ggcgacgatg 240

cgtagccgac ctgagagggt gatcggccac actgggactg agacacggcc cagactccta 300

cgggaggcag cagtagggaa tcttccacaa tgggcgaaag cctgatggag caacgccgcg 360

tgagtgaaga aggatttcgg ttcgtaaaac tctgttgtaa gggaagaaca agtacagtag 420

taactggctg taccttgacg gtaccttatt agaaagccac ggctaactac gtgccagcag 480

ccgcggtaat acgtaggtgg caagcgttgt ccggaattat tgggcgtaaa gcgcgcgcag 540

gtggtttctt aagtctgatg tgaaagccca cggctcaacc gtggagggtc attggaaact 600

gggagacttg agtgcagaag aggatagtgg aattccaagt gtagcggtga aatgcgtaga 660

gatttggagg aacaccagtg gcgaaggcga ctatctggtc tgtaactgac actgaggcgc 720

gaaagcgtgg ggagcaaaca ggattagata ccctggtagt ccacgccgta aacgatgagt 780

gctaagtgtt agggggtttc cgccccttag tgctgcagct aacgcattaa gcact 835

Claims

1. The spherical lysine bacillus (Lysinibacillus sphaericus) SY50 has a preservation number of CCTCC NO: m2019841.

2. A microbial preparation comprising the spherical lysine bacillus SY50 according to claim 1.

3. An agricultural fertilizer, a phosphorus activator, a plant growth promoter, a heavy metal pollution degradation agent or an iron chelating agent prepared from the spherical lysine bacillus SY50 as claimed in claim 1 or the microbial agent as claimed in claim 2.

4. The spherical lysine bacillus SY50 as claimed in claim 1 or any one of the following applications of the microbial inoculum as claimed in claim 2:

1) for promoting plant growth and development and increasing crop yield; the crop is corn;

2) dissolving phosphorus;

3) the method is used for repairing heavy metal pollution; the heavy metal is iron;

4) the method is used for preparing agricultural fertilizers;

5) used for preparing a phosphorus activator;

6) for the preparation of plant growth promoters; the plant is corn;

7) used for preparing heavy metal pollution degradation agent; the heavy metal is iron;

8) used for preparing iron chelating agent.

5. Use of the spherical lysine bacillus SY50 according to claim 1 or the microbial inoculum according to claim 2 for dissolving insoluble phosphorus.

6. The use according to claim 5, wherein said sparingly soluble phosphorus is a sparingly soluble inorganic phosphorus and a sparingly soluble organic phosphorus.