A strain of Bacillus Horikoshii P1 capable of adsorbing and passivating heavy metals and its application

Abstract

The present invention belongs to the field of microbial technology, discloses a strain of Bacillus Horikoshii P1 capable of adsorbing and passivating heavy metals and its application, and specifically discloses a strain of Bacillus Horikoshii capable of adsorbing and passivating heavy metals, wherein the Bacillus Horikoshii is deposited as Sutcliffiella horikoshii P1, and is deposited in Guangdong Microbial Culture Collection Center, with a deposit number of GDMCC No: 63215, and a deposit date of March 2, 2023. The present invention discloses for the first time the role of Bacillus Horikoshii in heavy metal adsorption and passivation, and the provided Bacillus Horikoshii has strong tolerance to heavy metals, strong phosphorus dissolving and urease producing capabilities, effectively adsorbs, fixes and mineralizes heavy metals, enhances the tolerance of plants to heavy metals, and protects plants from the influence of abiotic stress to promote plant growth.

Description

Technical Field

[0001] The invention belongs to the technical field of microorganisms, and specifically relates to a strain of Bacillus Horikoshii P1 capable of adsorbing and passivating heavy metals and application thereof. Background Art

[0002] In recent years, due to the increased use of lead and zinc mining, smelting, atmospheric deposition and agricultural chemicals, the pollution of heavy metals such as copper, cadmium, lead and zinc in the environment has become increasingly serious. Heavy metals are transmitted to the human body through the food chain, which can cause irreversible chronic liver damage, osteoporosis, and even cancer. In particular, cadmium has the characteristics of long half-life, high mobility and easy absorption and accumulation by crops, which has a strong toxic effect on organisms. Microbial remediation of heavy metal-contaminated water and soil has economic and green advantages, but it is easily affected by the external environment. Exploring microbial resources with strong environmental tolerance is a research hotspot for microbial remediation of heavy metal pollution.

[0003] Phosphorus is an essential nutrient for plant growth and development, but it is easily fixed in the soil through adsorption and precipitation, making it difficult for plants to use it. If there is a lack of phosphorus in the soil, it will seriously affect the life activities of plants. Phosphorus-dissolving microorganisms can convert the ineffective phosphorus in the soil into effective phosphorus that can be directly used by plants. At the same time, they can also fix heavy metals in polluted soil environments, improve plant disease resistance, and improve soil structure. Phosphorus-dissolving bacteria play an important role in the remediation and improvement of heavy metal-contaminated soils.

[0004] Bacillus Horikoshii was first reported by Nielsen et al. in 1995. In 2016, researchers screened out this strain from oil- and water-flooded contaminated soil and found that it had a good oil degradation effect. However, as a new strain resource, its growth characteristics and other functional properties have not yet been explored and studied. Summary of the invention

[0005] The first aspect of the present invention aims to provide a Bacillus Horikoshii that can adsorb and passivate heavy metals.

[0006] The second aspect of the present invention aims to provide a Bacillus agent.

[0007] The third aspect of the present invention aims to provide use of the Bacillus Horikoshi of the first aspect of the present invention and / or the Bacillus agent of the second aspect of the present invention.

[0008] The fourth aspect of the present invention aims to provide a method for promoting plant growth under heavy metal stress environment.

[0009] In order to achieve the above object, the technical solution adopted by the present invention is:

[0010] The first aspect of the present invention is to provide a Bacillus Horikoshii that can adsorb and passivate heavy metals. The Bacillus Horikoshii is deposited under the name Sutcliffiella horikoshii P1, is deposited in the Guangdong Provincial Microbiological Culture Collection Center, has a deposit number of GDMCC No: 63215, and has a deposit date of March 2, 2023.

[0011] The second aspect of the present invention is to provide a Bacillus agent, comprising at least one of the Bacillus Horikoshi of the first aspect of the present invention, a fermentation culture of the Bacillus Horikoshi of the first aspect of the present invention, spores of the Bacillus Horikoshi of the first aspect of the present invention, and a fermentation supernatant of the Bacillus Horikoshi of the first aspect of the present invention.

[0012] The active ingredients of the above-mentioned bacterial agent may be the above-mentioned Bacillus Horikoshi, the culture of the above-mentioned Bacillus Horikoshi (such as a fermentation product) and / or the spores of the above-mentioned Bacillus Horikoshi. The active ingredients of the above-mentioned bacterial agent may also contain other biological components or non-biological components. The other active ingredients of the above-mentioned bacterial agent can be determined by those skilled in the art according to the effect of the bacterial agent.

[0013] The term "culture" refers to a liquid or solid product (all substances in the culture container, fermentation products) that has a microbial community after artificial inoculation and culture. That is, the product obtained by growing and / or amplifying microorganisms, which can be a biologically pure culture of microorganisms, or it can contain a certain amount of culture medium, metabolites or other components produced during the culture process.

[0014] In the above-mentioned microbial agent, in addition to the active ingredient, the microbial agent also contains a carrier. The carrier can be a commonly used and biologically inert carrier in the field (such as microorganisms, agriculture). The carrier can be a solid carrier or a liquid carrier; the solid carrier can be a mineral material, a plant material or a polymer compound; the mineral material can be at least one of clay, talc, kaolin, montmorillonite, white carbon, zeolite, silica and diatomaceous earth; the plant material can be at least one of corn flour, soybean flour and starch; the polymer compound can be polyvinyl alcohol and / or polyglycol; the liquid carrier can be an organic solvent or water; the organic solvent can be decane and / or dodecane.

[0015] The above-mentioned bacterial agents may be in various dosage forms, such as liquid, emulsion, suspension, powder, granule, wettable powder or water dispersible granule.

[0016] According to needs, a binder, a stabilizer (such as an antioxidant), a pH adjuster, etc. may be added to the bacterial agent.

[0017] The third aspect of the present invention is to provide use of the Bacillus Horikoshi of the first aspect of the present invention and / or the Bacillus agent of the second aspect of the present invention in any one of (1) to (11);

[0018] (1) Adsorption and passivation of heavy metals;

[0019] (2) preparing products for adsorbing and passivating heavy metals;

[0020] (3) Remediation of heavy metal contaminated soil;

[0021] (4) Preparation of products for the remediation of heavy metal contaminated soil;

[0022] (5) Improve plant tolerance to heavy metal stress;

[0023] (6) preparing products that improve plant tolerance to heavy metal stress environments;

[0024] (7) Promote plant germination and growth;

[0025] (8) Preparation of products that promote plant growth;

[0026] (9) Promote plant root growth;

[0027] (10) Preparing products that promote plant root growth;

[0028] (11) Preparation of urease.

[0029] Preferably, the heavy metals described in (1) to (6) include one or more of copper, cadmium, lead, zinc, tin, nickel, cobalt, antimony, mercury and bismuth.

[0030] Preferably, the heavy metals described in (1) to (6) include copper, lead and cadmium.

[0031] Preferably, the plants described in (5) to (10) include dicotyledonous plants and / or monocotyledonous plants.

[0032] Preferably, the plants include cruciferous plants and / or grass plants.

[0033] Preferably, the cruciferous plants include one or more of the genera Brassica, Raphanus, Isatis, Herba Lysimachiae, Capsella, Nymphoides, and Brassica, including but not limited to rapeseed, Chinese cabbage, Chinese cabbage, purple cabbage, red cabbage, broccoli, cauliflower, cabbage, kale, radish, mustard, cauliflower, Chinese mustard, Arabidopsis, and the like.

[0034] Preferably, the grass plant includes one or more of the genera Oryza, Capsicum, Aquilegia, Hordeum, and Avena, including but not limited to wheat, rice, corn, barley, sorghum, and the like.

[0035] The fourth aspect of the present invention is to provide a method for promoting plant growth under heavy metal stress environment, which comprises the step of using the Bacillus Horikoshi of the first aspect of the present invention or the Bacillus agent of the second aspect of the present invention to act on the plant.

[0036] Preferably, the Bacillus Horikoshii or the Bacillus agent is applied to the plant by applying, wetting, drenching, atomizing, drizzling, spraying, atomizing, or soaking.

[0037] Preferably, the bacterial solution of Bacillus Horikoshi or the Bacillus agent is allowed to act on the plant by immersion.

[0038] Preferably, the OD of the bacterial solution is 600 =0.2~2.0; further 1.0~2.0.

[0039] Preferably, the bacterial liquid concentration is 0.5 to 2 g / L (wet weight); further preferably, 1 to 2 g / L (wet weight).

[0040] Preferably, the soaking time is 3 to 6 hours; further preferably 4 to 5 hours.

[0041] Preferably, the plants include cruciferous plants and / or grass plants.

[0042] Preferably, the cruciferous plants include one or more of the genera Brassica, Raphanus, Isodon, Herba Lysimachiae, Capsella, Nymphoides, and Brassica, including but not limited to rapeseed, Chinese cabbage, Chinese cabbage, Chinese cabbage, purple cabbage, red cabbage, broccoli, cauliflower, cabbage, kale, radish, mustard, cauliflower, Chinese mustard, Arabidopsis, and the like.

[0043] Preferably, the grass plant includes one or more of the genera Oryza, Capsicum, Aquilegia, Hordeum, and Avena, including but not limited to wheat, rice, corn, barley, sorghum, and the like.

[0044] The beneficial effects of the present invention are:

[0045] The present invention discloses for the first time the role of Bacillus Horikoshi in heavy metal adsorption and passivation. The provided Bacillus Horikoshi has strong tolerance to heavy metals, strong phosphorus dissolving and urease producing abilities, can effectively adsorb, fix and mineralize heavy metals, can enhance plant tolerance to heavy metals, protect plants from abiotic stresses to promote plant growth, and can provide new strain resources and references for ecological restoration projects of soil contaminated by toxic heavy metals.

[0046] The present invention uses Bacillus Horikoshi's bacterial solution to soak the seeds of non-heading Chinese cabbage. The results show that the bacterial solution can significantly improve the seed germination rate and vitality index under heavy metal stress, especially under high heavy metal stress environment. When the Cd concentration is 50 mg / L, the seed germination rate is increased by 11.67%, and the vitality index is increased from 30.80 to 79.98. BRIEF DESCRIPTION OF THE DRAWINGS

[0047] Figure 1 This is the growth curve of Bacillus Horikoshii P1.

[0048] Figure 2 This is the phylogenetic tree of Bacillus Horikoshi P1.

[0049] Figure 3 The above are the results of the change of phosphorus solubilization amount of Bacillus Horikoshi P1 over time, where a is the change of phosphorus solubilization amount of inorganic phosphorus by Bacillus Horikoshi P1 over time, and b is the change of phosphorus solubilization amount of organic phosphorus by Bacillus Horikoshi P1 over time.

[0050] Figure 4 This is a real picture of the 48h urease positive test results of Bacillus Horikoshi P1.

[0051] Figure 5 The results show that the urease activity of Bacillus Horikoshi P1 changes over time.

[0052] Figure 6 The results of removal of different heavy metal solutions by Bacillus Horikoshi P1.

[0053] Figure 7 This is a real picture of the growth of non-heading cabbage in different treatment groups under 50 mg / L cadmium solution stress.

[0054] Figure 8 Figure 2 is the effect of Bacillus Horikoshi P1 on the germination potential, germination rate and vitality index of non-heading cabbage, where a is the effect of Bacillus Horikoshi P1 on the germination potential of non-heading cabbage, b is the effect of Bacillus Horikoshi P1 on the germination rate of non-heading cabbage, and c is the effect of Bacillus Horikoshi P1 on the vitality index of non-heading cabbage. DETAILED DESCRIPTION

[0055] The present invention will now be described in detail with reference to specific embodiments, but the scope of the present invention is not limited thereto.

[0056] Unless otherwise specified, the materials and reagents used in this example were obtained from commercial sources.

[0057] LB liquid culture medium: 5 g yeast extract powder, 10 g tryptone, 5 g NaCl, 1 L distilled water, adjust pH to 7.0-7.2, sterilize and set aside.

[0058] LB solid medium: Add 2.0 w / w% to 2.3 w / w% agar to LB liquid medium.

[0059] Inorganic phosphorus culture medium: Ca3(PO4)2 5.0g, glucose 10g, (NH4)2SO4 0.5g, NaCl 0.3g, KCl0.3g, MgSO4·7H2O 0.3g, FeSO4·7H2O 0.03g, MnSO4·H2O 0.03g, yeast extract powder 0.5g, distilled water 1L, adjust pH 7.0-7.2, sterilize and set aside.

[0060] Organophosphorus culture medium: glucose 10g, (NH4)2SO4 0.5g, NaCl 0.3g, KCl 0.3g, MgSO4·7H2O0.3g, FeSO4·7H2O 0.03g, MnSO4·H2O 0.03g, CaCO3 1g, yeast extract powder 0.5g, lecithin 0.2g, 1L distilled water, pH 7.0-7.2, sterilize and set aside.

[0061] Organophosphorus solid culture medium: Add 2.0w / w% to 2.3w / w% agar to the organophosphorus culture medium.

[0062] Example 1 Isolation and screening of strains

[0063] Isolation and screening of phosphate-solubilizing bacteria:

[0064] The soil samples for initial screening of strains were collected from saline soil contaminated by heavy metals in Qingdao, Shandong Province (36°09′50″N: 120°03′54″E). The soil was placed in a sterile bag and brought back to the laboratory and stored at 4°C. 10 g of fresh soil sample was weighed and added to 90 mL of sterile saline and shaken at 150 r / min for 30 min. After standing for 30 min, the supernatant was diluted to 10 -3 , 10 -4 and 10 -5 , take 50 μL of bacterial solution of different dilutions and spread it on inorganic phosphorus culture medium, invert it and place it in a 28℃ incubator for 4-5 days. Pick the colonies that can produce phosphate-dissolving rings and repeatedly streak them. Spread the purified strains on organic phosphorus solid culture medium, pick the single bacteria that can produce phosphate-dissolving rings, that is, get phosphate-dissolving bacteria, transfer it to LB solid culture medium slant and store it at 4℃ for later use.

[0065] Example 2

[0066] This example is used to identify the phosphate-dissolving bacteria screened in Example 1.

[0067] 1. Morphological characteristics and characteristics of strains

[0068] By observing the characteristics of the colonies and conducting biochemical experiments such as Gram staining on the strain, the results showed that the colonies of the strain were light yellow with a whitish hue, with a raised center, neat edges, smooth and moist, and opaque. It was a Gram-positive bacterium that could produce indoleacetic acid. Further investigation of the growth curve of the strain in LB liquid medium showed that the lag phase of the strain was 0 to 4 hours, the logarithmic growth phase was 4 to 18 hours, and the stable phase was 18 to 48 hours ( Figure 1 ), based on the growth and physiological and biochemical characteristics of the strain, the strain was preliminarily identified as Bacillus Horikoshi.

[0069] 2.16S rDNA sequence

[0070] The 16S rDNA gene of the phosphate-soluble bacteria screened in Example 1 was amplified using 16S rDNA universal primers 27F (AGAGTTTGATCCTGGCTCA (SEQ ID NO: 2)) and 1492R (GGTTACCTTGTTACGACTT (SEQ ID NO: 3)), and its 16S rDNA sequence is shown in SEQ ID NO: 1. The obtained 16S rDNA gene sequence was further compared with the NCBI database, and a phylogenetic tree was constructed using the neighbor-joining method. The results showed that the sequence of the strain had a sequence homology of 99.57% with that of Sutcliffiellahorikoshii stra.

[0071] Based on the results of molecular biology and morphology, the strain was identified as Bacillus Horikoshii, named Bacillus Horikoshii P1, and deposited in Guangdong Provincial Microbiological Culture Collection Center with the preservation name Sutcliffiella horikoshiiP1, the preservation number GDMCC No: 63215, and the preservation date: March 2, 2023.

[0072] Example 3 Characterization of resistance of Bacillus Horikoshii P1 to heavy metals

[0073] The minimum inhibitory concentration (MIC) was used to indicate the resistance of Bacillus Horikoshi P1 to heavy metal Cd. 50 μL of cadmium nitrate solution with concentrations of 100 mg / L, 200 mg / L, 300 mg / L, 400 mg / L, 500 mg / L, 600 mg / L, 700 mg / L, 800 mg / L, and 1000 mg / L was added to a 96-well plate, and the control group was set without heavy metal solution. In addition to the control group, 50 μL of Bacillus Horikoshi P1 diluted bacterial solution (2×10 10 CFU / mL), and cultured in a 37°C incubator for 18-24 hours. Observe whether the liquid in the well plate is turbid to determine whether the strain is inhibited.

[0074] The results show that the diluted bacterial solution of Bacillus Horikoshi P1 is still turbid in 700 mg / L cadmium nitrate solution, but clear in 800 mg / L solution, indicating that the growth of the strain is inhibited, that is, 800 mg / L is the minimum inhibitory concentration of the bacteria.

[0075] Example 4 Determination of Phosphate Solubilization Capacity of Bacillus Horikoshi P1

[0076] The strain preserved in Example 1 was inoculated into LB liquid culture medium and cultured in a shaking incubator at 30°C and 150 r / min for 24 h. The bacterial solution was resuspended in physiological saline (2×10 10 CFU / mL), 1mL of bacterial solution was inoculated into 100mL of inorganic phosphorus culture medium (tricalcium phosphate as the only phosphorus source) and organic phosphorus culture medium, respectively, and fermented on a shaking table at 30℃ and 150r / min, with no bacterial solution as the blank control group. Take 2mL of fermentation broth every day and centrifuge at 10000r / min for 10min, and determine the soluble phosphorus content of the solution by molybdenum antimony colorimetry. Use the blank culture medium as the reference solution to adjust the instrument zero point, read the absorbance at 700nm, and find the corresponding soluble phosphorus content of the culture broth from the standard curve. At the same time, determine the pH value of the fermentation broth in the inorganic phosphorus system and the alkaline phosphatase content in the organic phosphorus system. Take 1mL of supernatant as the test solution, use disodium p-nitrophenyl phosphate (150mmol / L) as the reaction substrate, determine the absorbance at 420nm of the system, and find the corresponding phosphatase activity from the standard curve. The number of micromoles of 1L fermentation broth reacting with the substrate for 1h and releasing the product is called 1 enzyme activity unit, recorded as μmol / Lh.

[0077] The results are as follows Figure 3 As shown in the figure, in the inorganic phosphorus system, the soluble phosphorus content was the highest on the 3rd day, which was 161.65 mg / L, and the solution pH was the lowest, which was 4.78. The dissolved phosphorus content of the organic phosphorus system was 67.21 mg / L on the 5th day, and the alkaline phosphatase (ALP) activity was 1000 μmol / Lh. The strain had good phosphorus dissolving characteristics.

[0078] Example 5 Determination of urease activity of Bacillus Horikoshii P1

[0079] Bacillus Horikoshi P1 was cultured on LB solid medium containing 2% (w / w) urea and 0.012g / L phenol red, and the color change of the medium was observed. At the same time, the change of urease activity of the strain over time was determined as follows: Bacillus Horikoshi P1 was inoculated into LB liquid medium containing 20g / L urea, and samples were taken at 0, 8, 12, 18, 24, 36, and 48h; 1mL of bacterial solution was mixed with 9mL of 1.11mM urea solution, and the change of conductivity at 0min and 5min was determined. The urease activity was calculated according to the following calculation formula: UA = (EC5-EC0) / 5×10×11 (mM urea min -1 )

[0080] By observing the color of LB solid medium, such as Figure 4 As shown in the figure, after the strain was cultured in this medium for 48 hours, the color changed from light yellow to light purple, indicating that the strain was urease-positive. By measuring the urease activity of the strain, the results showed that as the growth time increased, its urease activity continued to increase. At the 48th hour of growth, the urease activity was the strongest, which was 25.20 mM urea min -1 ( Figure 5 ).

[0081] Example 6 Heavy Metal Adsorption Characteristics of Bacillus Horikoshii P1

[0082] Bacillus Horikoshi P1 was inoculated into LB solid culture medium for activation for 24 hours; then 2 to 3 loops of colonies were scraped into LB liquid culture medium with a pH of 7.0, and cultured in a shaking incubator at 30°C and 150 r / min for 18 to 24 hours; the bacterial solution was resuspended with 0.9% saline, and inoculated into LB liquid culture medium (pH of 6.0, bacterial concentration of 1 g / L (wet weight)) containing Cd (5 mg / L), Cu (10 mg / L), and Pb (100 mg / L), respectively, and cultured in a shaking incubator at 30°C and 150 r / min for 24 hours; the supernatant was taken, filtered through a 0.22 μm filter, and the contents of Cd, Cu, and Pb in the supernatant were determined by an atomic absorption spectrophotometer, and the uninoculated culture medium was used as the control group to calculate the removal rate of heavy metals. Heavy metal removal rate = (heavy metal content of the supernatant of the uninoculated culture medium - heavy metal content of the supernatant of the inoculated culture medium) / heavy metal content of the uninoculated supernatant × 100%.

[0083] Depend on Figure 6 It can be seen that Bacillus Horikoshi P1 can remove 98.85% of 5 mg / L heavy metal Cd, 97.03% of 100 mg / L lead, and 34.31% of 10 mg / L copper within 24 hours, indicating that Bacillus Horikoshi P1 has a good heavy metal removal effect.

[0084] Example 7 Effect of soaking seeds with Bacillus Horikoshi P1 on germination of cabbage seeds

[0085] After activation, Bacillus Horikoshi P1 was inoculated into LB liquid culture medium and cultured at 30°C and 180 r / min for 24 h. The culture solution was divided into sterile centrifuge tubes and centrifuged at 6000 r / min for 10 min to collect the cells. The cells were washed three times with sterile saline and adjusted to OD 600 =1.0 bacterial suspension.

[0086] Select plump and healthy non-heading Chinese cabbage seeds, sterilize them with 0.5% H2O2 for 10 minutes, rinse them with sterile water for 5 times, and dry them for later use. 600 =1.0 in a bacterial suspension for 4 hours, with seeds soaked in physiological saline as the control. 4 mL of different concentrations of Cd solution (1 mg / L, 5 mg / L, 10 mg / L, 50 mg / L) were added to the culture dish (9 cm in diameter), two layers of sterile filter paper were placed in the dish, and 30 soaked non-heading Chinese cabbage seeds were evenly placed on them. They were cultured in a 25°C incubator with a light and dark cycle of 16 h and 8 h, respectively. Water was added to the constant weight by weighing. There were 3 replicates in each group, and the germination potential was calculated on the 3rd day, and the germination rate and root length were calculated on the 7th day. The calculation formula is as follows:

[0087] Germination potential (%) = (number of germinated seeds on the third day / total number of test seeds) × 100%;

[0088] Germination rate (%) = (number of germinated seeds on the 7th day / total number of seeds tested) × 100%;

[0089] Germination index = ∑(number of germinations on day t / corresponding number of germination days);

[0090] Vitality index = root length × germination index.

[0091] Table 1 Root length of non-heading cabbage seedlings in different treatment groups on day 7

[0092]

[0093] The results are as follows Figure 7 and Figure 8 As shown in Table 1, soaking in Bacillus Horikoshi P1 can improve the germination potential and germination rate of non-heading cabbage, especially under high Cd content; under 50 mg / L Cd stress, the germination rate of seeds soaked in Bacillus Horikoshi P1 solution increased by 11.67%, and the vitality index increased from 30.80 to 79.98. By comparing the root length of non-heading cabbage seedlings in different treatment groups after germination for 7 days, the results are shown in Table 1. Under the stress of Cd concentration of 5-50 mg / L, soaking seeds with Bacillus Horikoshi P1 can significantly increase the root length of seedlings.

[0094] The embodiments of the present invention are described in detail above in conjunction with the accompanying drawings, but the present invention is not limited to the above embodiments. Various changes can be made within the knowledge of ordinary technicians in the relevant technical field without departing from the purpose of the present invention. In addition, the embodiments of the present invention and the features in the embodiments can be combined with each other without conflict.

Claims

1. A Bacillus Horikoshii capable of adsorbing and passivating heavy metals, characterized in that: The preservation name of the Bacillus Horikoshii is Sutcliffiella horikoshii P1, which is preserved in the Guangdong Provincial Microbiological Culture Collection Center. The preservation number is GDMCCNo: 63215, and the preservation date is March 2, 2023.

2. A Bacillus agent, characterized in that The method comprises at least one of the Bacillus Horikoshii according to claim 1, a fermentation culture of the Bacillus Horikoshii according to claim 1, and spores of the Bacillus Horikoshii according to claim 1.

3. Use of the Bacillus Horikoshi described in claim 1 and / or the Bacillus agent described in claim 2 in any one of (1) to (11); (1) Adsorption and passivation of heavy metals; (2) preparing products for adsorbing and passivating heavy metals; (3) Remediation of heavy metal contaminated soil; (4) Preparation of products for the remediation of heavy metal contaminated soil; (5) Improve plant tolerance to heavy metal stress; (6) preparing products that improve plant tolerance to heavy metal stress environments; (7) Promote plant germination and growth; (8) Preparation of products that promote plant growth; (9) Promote plant root growth; (10) Preparing products that promote plant root growth; (11) preparing urease; The plant described in (5) to (10) is Chinese cabbage.

4. The use according to claim 3, characterized in that: The heavy metals described in (1) to (6) include one or more of copper, cadmium, lead, zinc, tin, nickel, cobalt, antimony, mercury and bismuth.

5. A method for promoting plant growth under heavy metal stress environment, comprising the step of using the Bacillus Horikoshi described in claim 1 or the Bacillus agent described in claim 2 to act on the plant, wherein the plant is cabbage.

6. The method according to claim 5, characterized in that The Bacillus Horikoshii or the Bacillus bacterial agent is allowed to act on the plant by applying, wetting, drenching, atomizing, drizzling, spraying, atomizing, or soaking.

7. The method according to claim 6, characterized in that The bacterial solution of Bacillus Horikoshi or the Bacillus bacterial agent is allowed to act on plants in an immersion manner.

8. The method according to claim 7, characterized in that The OD of the bacterial solution 600 =0.2~2.

0.

9. The method according to claim 8, characterized in that The soaking time is 3 to 6 hours.

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