Bacillus velezensis BLS-JW1 and application thereof in plant growth promotion and saline alkali soil improvement

Abstract

The invention belongs to the technical field of microorganisms, and particularly relates to bacillus velezensis BLS-JW1 and application thereof in plant growth promotion and saline-alkali soil improvement. The strain is preserved on November 21, 2024, and the preservation number is CGMCC (China General Microbiological Culture Collection Center) No.32736. In the aspect of plant growth promotion, the prepared fungicide is used for industrial pepper in saline-alkali soil, the plant height and the leaf number can be remarkably increased, the overground and underground biomass can be improved, plants can grow more robustly, and the possibility is provided for improving the yield of crops in saline-alkali soil. In the aspect of saline-alkali soil improvement, the microbial agent can reduce the pH value, volume weight and salt content of soil, improve the content of rapidly available phosphorus in the soil and the proportion of water-stable large aggregates, and effectively optimize the structure and fertility of the soil. Compared with a traditional improvement method, biological improvement is environmentally friendly and low in cost, a new path is opened up for saline-alkali soil treatment and agricultural sustainable development, and the application prospect is wide.

Description

Technical Field

[0001] The invention relates to the technical field of microorganisms, in particular to Bacillus Velezii BLS-JW1 and applications thereof in plant growth promotion and saline-alkali soil improvement. Background Art

[0002] Land salinization has become a serious problem that restricts the development of agriculture, forestry and animal husbandry economy worldwide, and poses a serious threat to ecological security. The saline-alkali components in the soil seriously affect its physical and chemical properties, causing soil compaction, poor air permeability and water permeability. At the same time, the high saline-alkali environment will have many adverse effects on the growth of most plants. In saline-alkali soil, the germination of seeds of plants is inhibited, the development of root systems is hindered, and the growth of the aboveground parts is affected, resulting in short plants, yellow leaves, and even death in severe cases, which greatly reduces crop yields.

[0003] In order to solve the problem of saline-alkali land, people have tried a variety of improvement methods. Physical improvement methods such as irrigation and drainage to wash salt have certain effects, but they require a lot of water resources and human and material resources, and are costly in the long run, making them difficult to implement on a large scale in areas with scarce water resources. Chemical improvement methods, such as the use of chemical improvers such as gypsum and ferrous sulfate, can adjust soil pH and salt content in the short term, but they are easy to damage soil structure and may cause soil compaction. There is also a potential risk of environmental pollution. In addition, the long-term use of chemical improvers will increase the cost of soil management and have an adverse impact on the sustainable development of the ecological environment.

[0004] In this context, biological improvement methods have gradually attracted widespread attention and in-depth research due to their high efficiency, low cost and no secondary pollution. Soil functional microorganisms have great application potential in saline soil remediation and improvement. However, screening microbial strains with high efficiency in promoting plant growth and improving saline-alkali soil is still the focus and difficulty of current research. Summary of the invention

[0005] The purpose of the present invention is to provide Bacillus Velezii BLS-JW1 and its application in plant growth promotion and saline-alkali soil improvement, providing an effective means.

[0006] In order to achieve the above-mentioned object of the invention, the present invention provides the following technical solutions:

[0007] The invention provides a Bacillus velezensis. The Bacillus velezensis is Bacillus velezensis BLS-JW1, and the deposit number is CGMCC No.32736.

[0008] The present invention also provides a culture medium for culturing the above-mentioned Bacillus Velez subtilis, which contains the following components in parts by weight: 0.1-1.0 parts of bran, 0.1-0.5 parts of bean cake powder, 0.5-1.0 parts of corn powder, 0.5-1.5 parts of sodium chloride, 0.05-0.1 parts of dipotassium hydrogen phosphate and 0.01-0.04 parts of manganese sulfate.

[0009] The present invention also provides a method for culturing the above-mentioned Bacillus Velez subtilis, comprising the following steps: inoculating Bacillus Velez subtilis BLS-JW1 into the above-mentioned culture medium, culturing, and obtaining Bacillus Velez subtilis culture fluid.

[0010] Preferably, the culturing time is more than 12 hours;

[0011] The culture temperature is 15-50°C.

[0012] The present invention also provides the Bacillus Velez subtilis culture solution obtained by the above-mentioned culture method.

[0013] The present invention also provides the use of the above-mentioned Bacillus Velez subtilis, the culture method or the culture solution of Bacillus Velez subtilis in the production of polysaccharides.

[0014] The present invention also provides the use of the above-mentioned Bacillus Velez subtilis, the culture method or the culture solution of Bacillus Velez subtilis in producing indoleacetic acid.

[0015] The present invention also provides the use of the above-mentioned Bacillus Velez, the culture method or the culture solution of Bacillus Velez in the preparation of a plant growth promoter.

[0016] The present invention also provides the use of the above-mentioned Bacillus Velez, the culture method or the culture solution of Bacillus Velez in the preparation of saline-alkali soil conditioner.

[0017] The invention also provides a saline-alkali soil conditioner, wherein the soil conditioner contains the Bacillus Velezii.

[0018] Beneficial effects of the present invention:

[0019] The present invention provides a Bacillus Velezii BLS-JW1, which shows extremely important value and broad application prospects in the fields of plant growth promotion and saline-alkali soil improvement.

[0020] In terms of plant growth promotion, the bacterial agent made from this strain has a strong promoting effect on the growth of industrial peppers in saline-alkali soils. It can significantly increase the plant height and number of leaves of peppers, increase the above-ground and underground biomass, make the plant root system more developed, and make the overall growth stronger. This feature is not only applicable to industrial peppers, but in theory it also has a potential growth-promoting effect on other crops that are subject to saline-alkali stress. Against the background of the continuous expansion of saline-alkali land in the world, this growth-promoting effect can help improve the yield and quality of crops in saline-alkali areas, alleviate food security pressures, and ensure the sustainable development of agriculture.

[0021] From the perspective of saline-alkali soil improvement, the Bacillus Velez BLS-JW1 agent can effectively reduce the pH value, bulk density and salt content of the soil, while increasing the soil available phosphorus content and the proportion of water-stable macroaggregates > 5 mm, greatly optimizing the soil structure and fertility. This means that the agent can improve the physical and chemical properties of the soil, so that the saline-alkali soil gradually changes to a direction that is more suitable for plant growth. Long-term use of the agent for soil improvement is expected to increase the yield of crops in medium and low saline-alkali fields. Compared with traditional physical and chemical improvement methods, biological improvement methods, with their advantages of high efficiency, low cost and pollution-free, are in line with the concept of sustainable development and provide a new green and environmentally friendly way for saline-alkali land management. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 It is the colony status diagram;

[0023] Figure 2 This is the result of the hemolysis test;

[0024] Figure 3 This is the result diagram of the phosphorus circle solution;

[0025] Figure 4 This is the result diagram of indoleacetic acid production;

[0026] Figure 5 This is a graph showing the results of the phosphate solubilization ability test of Bacillus Velez BLS-JW1;

[0027] Figure 6 This is a graph showing the results of the polysaccharide production capacity test of Bacillus Velezii BLS-JW1;

[0028] Figure 7 This is a graph showing the results of the colonization ability test of Bacillus Velezii BLS-JW1.

[0029] Biological Deposit Description

[0030] The Bacillus velezensis provided by the present invention is named Bacillus velezensis BLS-JW1 (Bacillus velezensis BLS-JW1), which was deposited in the General Microbiology Center of the China Microorganism Culture Collection Administration on November 21, 2024, referred to as CGMCC, address: No. 3, Yard No. 1, Beichen West Road, Chaoyang District, Beijing. Institute of Microbiology, Chinese Academy of Sciences, Postal Code: 100101, and the deposit number is CGMCC No.32736. DETAILED DESCRIPTION

[0031] The technical solutions provided by the present invention are described in detail below in conjunction with the embodiments, but they should not be construed as limiting the protection scope of the present invention.

[0032] Example

[0033] 1. Preliminary screening of rhizosphere microorganisms of Suaeda salsa

[0034] 1.1 Test materials

[0035] Rhizosphere soil collection: Select healthy and strong Suaeda salsa in saline-alkali areas, dig out the Suaeda salsa plants, shake off their rhizosphere soil, and store them in a 4℃ refrigerator for later use.

[0036] Saline-alkali culture medium: 10g peptone, 5g yeast powder, 25g sodium chloride, 15g agar, 1.0L distilled water, adjust the pH to 10.0 with sodium hydroxide. Sterilize at 121℃ for 15min for later use.

[0037] 1.2 Test methods

[0038] Weigh 1g of the collected soil sample, add a culture medium with a 1% salt concentration, and shake at 30°C and 200r / min for 24 hours. Pipette 100 microliters of the shaken liquid and apply it to LB plates with 2.5% salt and pH 10. The grown colonies are tested for safety according to the General Technical Guidelines for Biosafety of Microbial Fertilizers (NY / T1109-2017); after safety is confirmed, transfer to a test tube slope for use.

[0039] 1.3 Test results:

[0040] Only three strains, alkali 5, alkali 7, and salt 3, grew on the LB plate containing 2.5% salt and pH 10 and were not hemolytic, so they were subjected to the next step of rescreening.

[0041] 2. Determination of the function of Suaeda salsa rhizosphere microorganisms

[0042] 2.1 Test materials

[0043] 2.1.1 Culture medium

[0044] Nitrogen fixation medium: glucose 10g, KH 2 PO4 0.2 g, MgSO 4· 7H 2 O 0.2g, NaCl 0.2g, CaSO 4 0.1 g, CaCO 3 5.0 g, distilled water 1000 mL, pH 7.0.

[0045] Phosphate-dissolving medium: glucose 10 g, NaCl 0.3 g, KCl 0.3 g, MgSO 4 7H 2 O 0.3g,

[0046] (NH 4 ) 2 SO 4 0.5 g, FeSO 4 ·2H 2 O 0.03g, MnSO 4 ·H 2 O 0.03g, Ca 3 (PO 3 ) 4 5.0g, distilled water 1000mL, pH 7.0~7.5.

[0047] Potassium-dissolving medium: sucrose 5.0 g, Na 2 HPO 4 2.0 g, MgSO 4 7H 2 O 0.5 g, FeCl 3 0.005 g, CaCO 3 0.1g, glass powder 1.0g (soluble K is removed by washing with water), distilled water 1000mL, pH 7.0-7.5.

[0048] PDA medium: 200 g potato, 20 g glucose, 15-20 g agar, 1000 ml distilled water, natural pH.

[0049] Polysaccharide production medium: sucrose 20g, yeast powder 3g, dipotassium hydrogen phosphate 0.5g, NaCl 10g, distilled water 1000mL, adjust pH 7.0-7.5, sterilize at 121℃ for 20min.

[0050] 2.2.2 Test strains

[0051] Three strains of bacteria were isolated in the initial screening.

[0052] 2.2 Test methods

[0053] The nitrogen fixation, phosphorus solubilization, potassium solubilization and indoleacetic acid (IAA) production performance of the three strains were determined using selective culture medium. The methods are as follows: nitrogen fixation, phosphorus solubilization and potassium solubilization were determined using the plate transparent circle method, and indoleacetic acid determination was determined using the indoleacetic acid determination kit;

[0054] 2.3 Test results

[0055] Base 5 has the ability to dissolve phosphate and produce indoleacetic acid and extracellular polysaccharides, so base 5 was selected for the next quantitative test.

[0056] Table 1 Functional determination of high salt and high alkali tolerant strains

[0057]

[0058] 3. Identification of strains

[0059] The strain numbered as Alkaline 5 was streaked out on a PDA medium plate to purify a single colony, and the single colony on the plate was sent to Shanghai Sangon Biotechnology Co., Ltd. for sequencing to obtain the 16S rDNA sequence. By analyzing the 16SDNA sequence of the strain and comparing it with the NCBI database, the strain was identified as Bacillus velez. The internal deposit number is BLS-JW1. The strain was deposited in the General Microbiology Center of the China Microbiological Culture Collection Administration on November 21, 2024, with the deposit number CGMCC No.32736.

[0060] 4. Determination of the functions of phosphate solubilization, polysaccharide production and indoleacetic acid production of salt-alkali tolerant strain BLS-JW1

[0061] 4.1 Test materials

[0062] The phosphate solubilization and polysaccharide production culture medium is the same as 2.1.1.

[0063] 4.2 Test methods

[0064] 4.2.1 Determination of phosphate solubilization capacity

[0065] The slant of Bacillus velezensis with Latin name Bacillus velezensis and deposit number CGMCC No.32736 was picked up with an inoculation loop, inoculated into 50 ml of liquid LB, and cultured for 10 hours under the conditions of 30°C and 200 rpm, and then inoculated into a 500 ml triangular flask containing 200 ml of phosphate-dissolving medium with a 2% inoculation amount, and the control group was inoculated with inactivated bacterial liquid, and each group was paralleled for 3 times. The shaking table was placed at 30°C and 200 rpm for 3 days, and the bacteria were removed by centrifugation, and the effective phosphorus content in the supernatant was determined by molybdenum antimony colorimetric method.

[0066] 4.2.2 Determination of indoleacetic acid production function:

[0067] Pick a ring of Bacillus Velezii BLS-JW1 bacterial lawn and inoculate it into an EP tube containing LB liquid medium, set it at 32°C and 200r / min, and culture it on a shaking table for 24h to obtain a bacterial suspension, then centrifuge the bacterial suspension at 10000r / min for 10min to obtain the supernatant. Determine OD according to the Salkowski reaction spectrophotometer colorimetric method 530 The value was compared with the standard curve to calculate the amount of indoleacetic acid produced by the strain.

[0068] 4.2.3 Exopolysaccharide production function assay

[0069] The slant of Bacillus Velezii BLS-JW1 was picked up with an inoculation loop and inoculated into 50 ml of liquid LB, and cultured for 10 hours at 30°C and 200 rpm. The inoculation amount was inoculated into a 500 ml triangular flask containing 300 ml of sugar production medium, and the control group was inoculated with inactivated bacterial liquid, with 3 parallels in each group. The shaking was placed in a shaker at 30°C and 200 rpm for 3 days, and the polysaccharide content in the fermentation broth was determined by anthrone colorimetry.

[0070] 4.2.4 Determination of the colonization ability of strains in saline-alkali soil

[0071] The seeds were first soaked in 75% ethanol for 1 minute, then soaked in 5.0% sodium hypochlorite for 10-15 minutes; finally, they were washed 3-4 times with sterile water. The fermentation liquid of Bacillus Velezii BLS-JW1 cultured overnight in LB medium was centrifuged at 8000r / min for 10 minutes.

[0072] Collect the cells. Use sterile water to suspend the cells to prepare 1×10 8 cfu / mL bacterial suspension. Soak the sterilized pepper seeds in the prepared bacterial suspension for 30 minutes, then sow them in pots filled with sterilized nutrient soil. Take rhizosphere soil at 0d, 7d, 14d, 21d, and 28d after sowing to count the colonies using the dilution plate method, and judge the rhizosphere colonization ability of the strain based on the changes in colonies at different periods.

[0073] 4.3 Test results

[0074] 4.3.1 Phosphate solubilization ability of Bacillus velez BLS-JW1

[0075] from Figure 5 It can be seen that Bacillus Velezii BLS-JW1 has a strong ability to decompose Ca 3 (PO 4 ) 2During the cultivation process, the available phosphorus content in the culture medium reached 25.33 mg / L at the 24th hour, and then increased rapidly. At 60 hours, the available phosphorus content in the fermentation broth reached the highest and tended to be stable, and the available phosphorus content was about 75.48 mg / L.

[0076] 4.3.2 Exopolysaccharide production capacity of Bacillus velezinii BLS-JW1

[0077] Depend on Figure 6 It can be seen that when Bacillus Velezii BLS-JW1 is cultured in sugar-producing medium, the peak period of sugar production is 24-60 hours, and the extracellular polysaccharide content of the fermentation broth can reach 2.5g / L after 60 hours. After that, the sugar production decreases and the extracellular polysaccharide content of the fermentation broth no longer increases.

[0078] 4.3.3 IAA production capacity of Bacillus velezinii BLS-JW1

[0079] After the Salkowski reaction, the color reaction of the fermentation supernatant of Bacillus velezinsis BLS-JW1 was as follows Figure 4 ; The amount of indoleacetic acid produced was measured and calculated to be 22 mg / L.

[0080] 4.3.4 Rhizosphere colonization ability of Bacillus velezinii BLS-JW1

[0081] Depend on Figure 7 It can be seen that the initial soil bacterial concentration of the inoculant inoculation was 0.5×10 8 cfu / g soil, while the rhizosphere soil bacterial content was detected 7 days after inoculation with the inoculant to be 1.5×10 8 cfu / g, the rhizosphere soil bacteria content reached 2.5×10 8 cfu / g, and then gradually stabilized. It can be seen that Bacillus Velezii BLS-JW1 can quickly colonize in the rhizosphere of plants.

[0082] 5. Preparation of inoculants

[0083] 5.1 Preparation of fermentation broth of Bacillus velezinii BLS-JW1

[0084] 5.1.1 Culture medium

[0085] Seed preparation medium: peptone 10g, yeast powder 5g, sodium chloride 10g, agar 15g, distilled water 1.0L.

[0086] Fermentation medium: bran 0.5%, bean cake powder 0.5%, corn powder 0.8%, sodium chloride 0.5%, dipotassium hydrogen phosphate 0.05%, manganese sulfate 0.02%. Bran needs to be boiled in water for 30 minutes and then filtered, and the filtrate is added.

[0087] 5.1.2 Fermentation process of Bacillus Velezii BLS-JW in 150L fermenter

[0088] Seed solution preparation: Wash the Kjergler flask slant seeds with full bacterial growth with 250 mL of sterile water.

[0089] Preparation of fermentation medium: Prepare according to the fermentation medium ratio. Fill 50-75% of the 50-liter fermentation tank. After adding the materials into the tank, sterilize at 121°C for 30 minutes. Cool to the culture temperature and set aside.

[0090] Inoculation: Use the differential pressure method, and the inoculation amount is 2 to 3 250mL Kjeldahl flasks / 35L fermentation medium.

[0091] Fermentation culture process: culture temperature 35 ~ 37 ℃, ventilation volume control: initial air volume 0.80 ~ 1.05m 3 / h, speed 80 ~ 100r / min, then the speed and air volume are adjusted alternately to maintain the dissolved oxygen level of the fermentation liquid not less than 20 ~ 40%, until the spore content in the fermentation liquid reaches more than 85% and the fermentation is completed to obtain the fermentation liquid.

[0092] At the end of fermentation, the fermentation liquid was counted using the dilution plate method, and the fermentation biomass could reach 4.5×10 9 cfu / mL.

[0093] 5.2 Preparation of Bacillus Velezii BLS-JW1 inoculant

[0094] The fermentation liquid of Bacillus Velez BLS-JW1 and peat were mixed in a mass ratio of 1:3 to prepare the Bacillus Velez BLS-JW1 inoculant. The bacterial content of the prepared inoculant can reach 1×10 9 cfu / mL or above. All indicators were tested and met the standards of GB20287-2006.

[0095] 6. Application test of Bacillus Velezii BLS-JW1

[0096] 6.1 Test materials

[0097] Cultivated crops: industrial pepper; Bacillus Velez subtilis BLS-JW1 inoculant; inactivated Bacillus Velez subtilis BLS-JW1 inoculant.

[0098] 6.2 Test methods

[0099] The pot experiment was conducted, and industrial pepper was selected as the cultivated crop. The test soil was finely sieved cultivated soil and river sand, which were fully mixed at a ratio of 1:1. The soil salt content was adjusted to 0.5%, and the soil was filled into the test pot at about two-thirds of the height for use. The experiment set up two treatments: inactivated Bacillus Velez BLS-JW1 (T1) and Bacillus Velez BLS-JW1 (T2), and the no-fertilization treatment (CK) was used as the control. The dosage per mu was 10kg. The diameter of the flower pot was 21cm. The dosage of the bacteria applied to each pot was calculated according to the area of ​​the flower pot and the dosage per mu, and the bacteria were applied around the seeds. Each treatment was repeated 15 times. After the seedlings emerged, the watering and management were the same. During this period, the position was changed every 1-2 days according to the sunshine conditions to achieve sunshine balance.

[0100] 6.2.1 Growth-promoting effect of Bacillus velezinii BLS-JW1

[0101] After the pepper seedlings had grown for 14 days, 5 pots were randomly selected to measure the plant height (length of the aboveground part) and the number of leaves; the pepper plants were washed and dried, divided into the aboveground part and the root, weighed separately, and the fresh weight of the aboveground part and the root was recorded; then the plants and roots were fixed at 105°C for 30 minutes, dried at 75°C to constant weight, weighed, and the aboveground dry weight and root dry weight were recorded.

[0102] 6.2.2 Effect of Bacillus Velezii BLS-JW1 on soil improvement

[0103] After the peppers had grown for 30 days, the rhizosphere soil was taken and the soil pH, bulk density, salinity, available phosphorus, and the ratio of large aggregates >5 mm in the soil to the total aggregates were measured according to the method of Technical Specifications for Functional Evaluation of Agricultural Microbial Agents GB / T41727-2022.

[0104] 6.3 Test results

[0105] 6.3.1 Growth-promoting effect of Bacillus Velezii BLS-JW1

[0106] As can be seen from Table 2, Bacillus Velez BLS-JW1 has a good growth-promoting effect on industrial pepper in saline-alkali soil. From the perspective of plant height, the plant height and leaf number of the treatment with Bacillus Velez BLS-JW1 increased by 15.32% and 16.67%, respectively; the dry and fresh weights of the aboveground parts were 14.47% and 17.10% higher than those of the control, respectively; from the perspective of the roots of the underground part, the fresh weight and dry weight were 15.36% and 17.95% higher than those of the control, respectively. It can be seen that Bacillus Velez BLS-JW1 can promote the development of the root system of industrial pepper and make the plants strong in saline-alkali environment.

[0107] Table 2 Effects of Bacillus Velezii BLS-JW1 on the growth of industrial peppers

[0108]

[0109] 6.3.2 Effect of Bacillus Velezii BLS-JW1 on the improvement of saline-alkali soil

[0110] Table 3 Effects of Bacillus Velezii BLS-JW1 on soil properties

[0111]

[0112] As shown in Table 3, compared with the control CK, the soil pH, bulk density and salt content of the treatment with Bacillus Velez subtilis BLS-JW1 were significantly decreased, which were significantly reduced by 0.39%, 10.34% and 9.22% respectively compared with CK (P<0.05), and the soil available phosphorus content and the proportion of water-stable macroaggregates >5 mm increased by 22.09% and 19.60% respectively, with significant differences; compared with the treatment with inactivated Bacillus Velez subtilis BLS-JW1, the soil pH, bulk density and salt content decreased by 0.25, 7.80% and 8.89% respectively (P<0.05), and the differences were also significant; and compared with the control, the inactivated Bacillus Velez subtilis BLS-JW1 treatment showed that all indicators were improved, but the differences were not significant. It can be seen that Bacillus Velez subtilis can improve the properties of saline-alkali soil and has the application effect of improving soil.

[0113] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principle of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. A Bacillus Velez, characterized in that The Bacillus velezensis is Bacillus velezensis BLS-JW1, and its deposit number is CGMCC No.32736.

2. A culture medium for culturing the Bacillus Velezii according to claim 1, characterized in that: The culture medium contains the following components in parts by weight: 0.1-1.0 part of bran, 0.1-0.5 part of bean cake powder, 0.5-1.0 part of corn powder, 0.5-1.5 parts of sodium chloride, 0.05-0.1 part of dipotassium hydrogen phosphate and 0.01-0.04 part of manganese sulfate.

3. A method for culturing Bacillus Velezii according to claim 1, characterized in that: The following steps are involved: The Bacillus Velez subtilis BLS-JW1 is inoculated into the culture medium according to claim 2 and cultured to obtain a Bacillus Velez subtilis culture solution.

4. The method for culturing Bacillus Velezii according to claim 3, characterized in that: The culturing time is more than 12 hours; The culture temperature is 15-50°C.

5. A culture solution of Bacillus velezensis obtained by the culture method according to claim 3 or 4.

6. Use of the Bacillus Velez subtilis according to claim 1, the culture method according to claim 3 or 4, or the culture solution of the Bacillus Velez subtilis according to claim 5 in producing polysaccharides.

7. Use of the Bacillus Velez subtilis according to claim 1, the culture method according to claim 3 or 4, or the culture solution of Bacillus Velez subtilis according to claim 5 in producing indoleacetic acid.

8. Use of the Bacillus Velez subtilis according to claim 1, the culture method according to claim 3 or 4, or the culture solution of Bacillus Velez subtilis according to claim 5 in preparing a plant growth promoter.

9. Use of the Bacillus Velez subtilis according to claim 1, the culturing method according to claim 3 or 4, or the Bacillus Velez subtilis culture solution according to claim 5 in preparing a saline-alkali soil conditioner.

10. A saline-alkali soil conditioner, characterized in that: The soil conditioner contains the Bacillus Velezii according to claim 1.

Images