Paenibacillus mucilaginosus and related products and uses thereof

Abstract

The application discloses a bacillus malleus and related products and application thereof, and relates to the field of microorganisms. The bacillus malleus is strain JH3, has high silicon dissolving capacity, can reach 44.71-47.87 mu g / mL, has multiple application modes, can be applied to agricultural production, improves the drought resistance of plants, promotes the growth of plants, reduces the agricultural cost, and is green and environment-friendly.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of microorganisms, in particular, to a bacillus mucilaginosus and related products and applications thereof. BACKGROUND

[0002] Tobacco is a high-value economic crop, and its planting area is usually located in mountainous areas where water supply is limited and drought is easy to occur. Drought has a serious impact on the entire life cycle of tobacco. During tobacco seedling stage, drought inhibits seed germination and emergence, affecting later transplanting and planting. During tobacco growth stage, drought affects tobacco tillering and root development, resulting in small tobacco plants, fewer leaves per plant, and small leaf area, reducing the photosynthetic capacity and stress resistance of tobacco leaves. During tobacco leaf maturation stage, drought leads to premature maturation of tobacco leaves, reduces the accumulation of effective chemical components in tobacco leaves, and affects the aroma and taste of tobacco leaves. Although some studies have focused on the drought resistance of tobacco, they mainly concentrate on the response, regulation and adaptation strategies of tobacco to drought stress, and improve the drought resistance of tobacco through crop breeding, agronomic measures and chemical additives.

[0003] Microorganisms participate in the life activities of tobacco such as water absorption, nutrient metabolism, hormone regulation and stress defense through complex interaction, and are one of the important factors affecting the drought resistance of tobacco. However, there are few studies on using microorganisms to improve the drought resistance of tobacco. Bioavailable silicon elements in soil can increase the stress resistance of plants, including resistance to drought, high temperature, low temperature, salt and alkali, heavy metals and other environmental stresses. However, silicon in soil exists in the form of insoluble silicate and cannot be directly absorbed and utilized by plants. Plant-microbe symbiosis can promote the dissolution of mineral elements in plant soil, and Bacillus mucilaginosus subsp. siliceus is a functional microorganism with clear silicic acid solubilizing activity. However, the main function of this strain is to solubilize potassium and phosphorus, and it has certain nitrogen fixation ability. The silicic acid solubilizing activity of the existing strain is low. The silicic acid solubilizing activity of P. mucilaginosus KN-18 strain (CCTCC NO. M2014321) in fermentation broth is 26.8 μg / mL, which is the strongest in the existing research in the field of agriculture.

[0004] At present, there is a lack of strains that can effectively improve the drought resistance of plants in the market.

[0005] In view of this, the present application is proposed. SUMMARY

[0006] The purpose of the present application is to provide a bacillus mucilaginosus and related products and applications thereof.

[0007] The present application is implemented as follows:

[0008] In a first aspect, an embodiment of the present application provides a Bacillus mucilaginosus JH3, which is taxonomically named Bacillus mucilaginosus subsp. siliceus, and has a preservation number of CGMCC No. 26781.

[0009] In a second aspect, an embodiment of the present application provides a culture, which is obtained by culturing the Bacillus mucilaginosus JH3 according to the preceding embodiment.

[0010] In a third aspect, an embodiment of the present application provides a biological bacterial agent, which contains the Bacillus mucilaginosus JH3 according to the preceding embodiment and / or the culture according to the preceding embodiment.

[0011] In a fourth aspect, an embodiment of the present application provides use of the Bacillus mucilaginosus JH3 according to the preceding embodiment or the culture according to the preceding embodiment or the biological bacterial agent according to the preceding embodiment in preparation of a fertilizer or a soil conditioner.

[0012] In a fifth aspect, an embodiment of the present application provides a fertilizer, which comprises or is obtained by fermentation of a mixture of a carrier and the Bacillus mucilaginosus JH3 according to the preceding embodiment or the culture according to the preceding embodiment or the biological bacterial agent according to the preceding embodiment.

[0013] In a sixth aspect, an embodiment of the present application provides a soil conditioner, which contains the Bacillus mucilaginosus JH3 according to the preceding embodiment or the culture according to the preceding embodiment or the biological bacterial agent according to the preceding embodiment or the fertilizer according to the preceding embodiment.

[0014] In a seventh aspect, an embodiment of the present application provides use of the Bacillus mucilaginosus JH3 according to the preceding embodiment or the culture according to the preceding embodiment or the biological bacterial agent according to the preceding embodiment or the fertilizer according to the preceding embodiment or the soil conditioner according to the preceding embodiment in any one of the following: (1) plant cultivation; (2) promoting plant growth or preparing a product for promoting plant growth; (3) improving drought resistance of plants or preparing a product for improving drought resistance of plants; (4) soil conditioning.

[0015] In an eighth aspect, an embodiment of the present application provides a screening medium, which comprises the following components and final concentrations of the components: 1-10 g / L of a saccharide, 1-5 g / L of Na2HPO4, 0.1-1 g / L of MgSO4·7H2O, 0.001-0.01 g / L of FeCl3, 0.01-0.5 g / L of CaCO3, 0.1-5 g / L of a silicon source, and 15-20 g / L of agar; wherein the silicon source comprises a silicate soil conditioner.

[0016] In a ninth aspect, the application provides use of the screening medium according to the above-mentioned embodiments in screening silicate bacteria.

[0017] (1) A new Paenibacillus mucilaginosus JH3 is provided, which has a high silicate dissolving capacity of 44.71-47.87 μg / mL;

[0018] (2) The Paenibacillus mucilaginosus JH3 can be applied in agriculture to improve the drought resistance of plants;

[0019] (3) The Paenibacillus mucilaginosus JH3 can reduce the use of silicon fertilizer, thereby reducing the cost of agriculture and protecting the environment;

[0020] (4) The Paenibacillus mucilaginosus JH3 can promote plant growth and improve soil quality.

[0021] (5) The Paenibacillus mucilaginosus JH3 has multiple application methods, and can be directly diluted and root irrigated, or applied to plant foliar spraying.

[0022] (6) The screening medium for silicate bacteria is improved, which shortens the screening period of silicate bacteria compared with the prior art, and provides a new way for obtaining silicate bacteria. BRIEF DESCRIPTION OF DRAWINGS

[0023] In order to more clearly illustrate the technical solutions of the embodiments of the application, the following will briefly introduce the drawings needed to be used in the embodiments. It should be understood that the following drawings only show some embodiments of the application, and therefore should not be regarded as a limitation to the scope. For those skilled in the art, other related drawings can also be obtained without creative labor on the basis of these drawings.

[0024] Figure 1 The colony morphology of the strain JH3 after growing on the screening medium for 48 hours (left), and the observation picture of the strain JH3 under a 1200 times microscope (right);

[0025] Figure 2 Silicate dissolving capacity of silicate bacteria on different culture media;

[0026] Figure 3 Carrier load of different materials;

[0027] Figure 4 Genome circle diagram of the strain JH3;

[0028] Figure 5 Phylogenetic tree of the strain JH3;

[0029] Figure 6 KEGG pathway analysis of the strain JH3;

[0030] Figure 7 Analysis of acid production pathway for strain JH3;

[0031] Figure 8 Analysis of secondary metabolite gene cluster for strain JH3;

[0032] Figure 9 Application of strain JH3 to pot simulation drought experiment;

[0033] Figure 10 Effect of applying JH3 inoculant on tobacco growth (Note: JH3 is a liquid microbial fertilizer); (a) Fresh weight of tobacco leaves; (b) Dry weight of tobacco leaves; (c) Leaf area of tobacco leaves; (d) Stem diameter of tobacco plants;

[0034] Figure 11 Effect of applying JH3 inoculant on soil available silicon and silicon content in plants (Note: JH3 is a liquid microbial fertilizer); (a) Content of available silicon in soil; (b) Content of silicon in plants;

[0035] Figure 12 Effect of applying JH3 inoculant on enzyme activity and osmotic adjustment substances of tobacco plants under drought conditions (Note: JH3 is a liquid microbial fertilizer); (a) Changes in POD content of tobacco leaves during drought stress; (b) Changes in CAT content of tobacco leaves during drought stress; (c) Changes in reducing sugar content of tobacco leaves during drought stress; (d) Changes in MDA content of tobacco leaves during drought stress;

[0036] Figure 13 Effect of applying JH3 inoculant on chlorophyll content of tobacco plants (Note: JH3 is a liquid microbial fertilizer); (a) Changes in chlorophyll a content of tobacco leaves during drought stress; (b) Changes in chlorophyll b content of tobacco leaves during drought stress; (c) Changes in chlorophyll a / b content of tobacco leaves during drought stress;

[0037] Figure 14 Effect of applying JH3 inoculant on water content of tobacco plants (Note: JH3 is a liquid microbial fertilizer); (a) Changes in leaf water content of tobacco leaves during drought stress; (b) Comparison of leaf conditions; (c) Comparison of whole plant conditions;

[0038] Figure 15 Effect of applying JH3 inoculant on growth conditions of tobacco plants in the field (Note: JH3 is a liquid microbial fertilizer); (a) Fresh weight of each part of tobacco leaves; (b) Dry weight of each part of tobacco leaves; (c) Biomass of each part of tobacco leaves; (d) Height of each part of tobacco plants;

[0039] Figure 16Effects of applying JH3 microbial agent and organic fertilizer in the field on the growth of tobacco plants; (a) Fresh weight of each part of tobacco leaves; (b) Dry weight of each part of tobacco leaves; (c) Biomass of each part of tobacco leaves; (d) Height of each part of tobacco plants; Note: FJ is a solid microbial fertilizer, which is obtained by compounding silicon-dissolving bacteria JH3 and organic fertilizer;

[0040] Figure 17 Effects of applying JH3 microbial agent and attapulgite in the field on the growth of tobacco plants; (a) Fresh weight of each part of tobacco leaves; (b) Dry weight of each part of tobacco leaves; (c) Biomass of each part of tobacco leaves; (d) Height of each part of tobacco plants; Note: ATJ is a solid microbial fertilizer, which is obtained by compounding silicon-dissolving bacteria JH3 and attapulgite;

[0041] Figure 18 Effects of applying JH3 microbial agent and attapulgite and organic fertilizer in the field on the growth of tobacco plants; (a) Fresh weight of each part of tobacco leaves; (b) Dry weight of each part of tobacco leaves; (c) Biomass of each part of tobacco leaves; (d) Height of each part of tobacco plants; Note: FAJ is a solid microbial fertilizer, which is obtained by compounding silicon-dissolving bacteria JH3, attapulgite and organic fertilizer. DETAILED DESCRIPTION

[0042] In order to make the purpose, technical solutions and advantages of the embodiments of the present application more clear, the technical solutions in the embodiments of the present application will be clearly and completely described below. If the specific conditions are not indicated in the embodiments, the conventional conditions or the conditions suggested by the manufacturers are adopted. If the reagents or instruments are not indicated by the manufacturers, they are all conventional products that can be purchased in the market.

[0043] In view of the problems in the prior art, the present application provides a new Bacillus mucilaginosus JH3, which has excellent silicon-dissolving capacity, the range of which can be 44.71-47.87 μg / mL, and can be applied in agriculture to improve the drought resistance of plants. Specifically, the soluble silicon produced by JH3 can alleviate the decrease in biomass index of plants under drought environment, promote the accumulation of osmotic adjustment substances and photosynthetic pigments, and improve the antioxidant enzyme activity; the soluble silicon produced by JH3 can also stimulate the formation of double-layer silicon dioxide cuticle in the epidermis of plant leaves, thereby reducing the water loss of leaves; in addition, the soluble silicon can be deposited on the cell wall, maintaining the characteristics of the cell wall and guard cells under drought stress, ensuring the normal operation of photosynthesis of plants, so as to enhance the resistance of plants to drought stress.

[0044] Secondly, the application of Bacillus mucilaginosus JH3 can reduce the use of silicon fertilizer, reduce agricultural costs, and protect the environment. At present, the mainstream silicon fertilizer products are calcium silicate made of industrial waste and water-soluble silicon fertilizer. The former is cheap but not easy to be absorbed by plants and has the risk of introducing other heavy metal ions. The latter is expensive and not easy to produce and promote. The silicon-dissolving bacteria JH3 (Bacillus mucilaginosus subsp. siliceus) provided in the embodiments has strong silicon-dissolving ability, can effectively dissolve the insoluble silicon in the soil, promote the absorption of plants, transport the soluble silicon to the stems and leaves through the roots, form silicified cells in the plants, enhance the resistance of the plants to substances such as malondialdehyde, and can enhance the mechanical strength of the stems and the disease resistance of the plants through the transportation of silicon, improve the photosynthetic pigments of the plants in drought stress, promote the growth and development of the plants in drought stress, and improve the drought resistance of the plants.

[0045] In addition, Bacillus mucilaginosus JH3 has various application methods, can be directly diluted and root-applied, or applied to plant foliar spraying to promote the absorption and utilization of effective silicon by plants. It can also be compounded with various materials (attapulgite, organic fertilizer or a combination thereof) to improve the application effect. For example, the JH3 is compounded with organic fertilizer to obtain a bio-organic fertilizer, which can be applied to improve the soil, balance the soil acidity and alkalinity, promote the growth of soil beneficial microorganisms, improve the soil enzyme activity, and promote the growth of plants. Compared with inorganic fertilizers on the market, the bio-organic fertilizer obtained by compounding the JH3 bacterial solution and the organic fertilizer has long-term effect. The high-efficiency silicon-dissolving effect of JH3 can continuously release soluble silicon, promote the absorption of plants, recruit beneficial microorganisms, and provide a better living environment for plant growth. For another example, the JH3 bacterial solution is compounded with attapulgite to obtain a mineral bio-bacterium. The attapulgite applied to the soil can improve the soil structure, increase the soil aeration and water retention capacity, and be beneficial to the growth and reproduction of microorganisms. The JH3 mixed with the attapulgite can efficiently release the effective silicon in the attapulgite, provide absorbable exogenous silicon for plants, provide nutrients for plant growth by the rich nitrogen, phosphorus and potassium in the attapulgite, increase the soil water retention, and increase the void structure to be beneficial to the respiration of plant roots.

[0046] Specific technical solutions

[0047] In one aspect, the embodiments of the present application provide a Bacillus mucilaginosus JH3, which is taxonomically named Bacillus mucilaginosus subsp. siliceus, and has a preservation number of CGMCC No. 26781.

[0048] Bacillus mucilaginosus subsp.siliceus JH3 was preserved in China General Microbiological Culture Collection Center on March 9, 2023, the address of the preservation center is No.1 Yard, North Chengxi Road, Beijing City, Chaoyang District, Institute of Microbiology of Chinese Academy of Sciences, the postcode is 100101, and the preservation number is CGMCC No.26781.

[0049] In another aspect, the embodiments of the present application also provide a culture obtained by culturing the Bacillus mucilaginosus JH3 described in the foregoing embodiments.

[0050] The culture conditions of JH3 are not particularly limited, and the existing culture medium and culture conditions applied to Bacillus mucilaginosus can be used.

[0051] In some embodiments, the culture conditions include that the temperature is 30-35℃, and specifically can be any one of 30, 31, 32, 33, 34, 35℃ or a range between any two of them.

[0052] In another aspect, the embodiments of the present application also provide a biological bacterial agent containing the Bacillus mucilaginosus JH3 described in the foregoing embodiments and / or the culture described in the foregoing embodiments.

[0053] In another aspect, the embodiments of the present application also provide the use of the Bacillus mucilaginosus JH3 described in any of the foregoing embodiments or the culture described in any of the foregoing embodiments or the biological bacterial agent described in any of the foregoing embodiments in the preparation of a fertilizer or a soil conditioner.

[0054] In another aspect, the embodiments of the present application also provide a fertilizer, which includes or is obtained by fermentation of a mixture of a carrier and the Bacillus mucilaginosus JH3 described in any of the foregoing embodiments or the culture described in any of the foregoing embodiments or the biological bacterial agent described in any of the foregoing embodiments.

[0055] In some embodiments, the mass ratio of the carrier to the Bacillus mucilaginosus JH3 or the culture or the biological bacterial agent is 8-9:1-2. The mass ratio specifically can be any one of 8:1, 8:1.2, 8:1.4, 8:1.6, 8:1.8, 8:2, 8.5:1, 8.5:1.2, 8.5:1.4, 8.5:1.6, 8.5:1.8, 8.5:2, 9:1, 9:1.2, 9:1.4, 9:1.6, 9:1.8, 9:2 or a range between any two of them.

[0056] In some embodiments, the carrier comprises a combination of any one or more of: an organic fertilizer and a silicate soil amendment.

[0057] In some embodiments, the silicate soil amendment comprises a combination of any one or more of: attapulgite, montmorillonite, and zeolite.

[0058] In some embodiments, when the carrier comprises an organic fertilizer and attapulgite, the mass ratio of the organic fertilizer and attapulgite is 1-2:4-39. The mass ratio can be specifically any one of 1:4, 1:10, 1:15, 1:20, 1:25, 1:30, 1:35, 1:39, 2:4, 2:10, 2:15, 2:20, 2:25, 2:30, 2:35, 2:39 or a range between any two of them.

[0059] In some embodiments, the fermentation conditions comprise 30-35℃ for 5-7 days. The fermentation temperature can be specifically any one of 30, 31, 32, 33, 34, 35℃ or a range between any two of them. The fermentation time can be specifically any one of 5, 5.5, 6, 6.5, 7 days or a range between any two of them.

[0060] In some embodiments, the fermentation further comprises controlling the moisture of the fermentation product to be ≤30%. The method of controlling the moisture can be through low-temperature drying technology, turning over every 8 hours, and measuring the moisture content of the fermentation product every certain period of time.

[0061] In some embodiments, the fertilizer is an agricultural fertilizer.

[0062] The organic fertilizer of the present application is not particularly limited and can be a commercially available organic fertilizer or prepared based on conventional technical knowledge.

[0063] In another aspect, the embodiments of the present application also provide a soil conditioner comprising the Bacillus mucilaginosus JH3 of any of the preceding embodiments, the culture of any of the preceding embodiments, the bio-inoculant of any of the preceding embodiments, or the fertilizer of any of the preceding embodiments.

[0064] In another aspect, the embodiments of the present application also provide the use of the Bacillus mucilaginosus JH3 of any of the preceding embodiments, the culture of any of the preceding embodiments, the bio-inoculant of any of the preceding embodiments, the fertilizer of any of the preceding embodiments, or the soil conditioner of any of the preceding embodiments in any of the following:

[0065] (1) plant cultivation; (2) promoting plant growth or preparing a product for promoting plant growth; (3) improving plant drought resistance or preparing a product for improving plant drought resistance; (4) soil conditioning.

[0066] In some embodiments, the plant comprises any one or more of tobacco, tomato, and soybean.

[0067] In some embodiments, the fertilizer comprises an agricultural fertilizer.

[0068] In some embodiments, the soil conditioning comprises: improving soil, adjusting soil pH, increasing soil nutrients, avoiding or reducing soil compaction.

[0069] In another aspect, the embodiments of the present application also provide a screening medium, which comprises the following components and final concentrations of the components: 1-10 g / L sugar, 1-5 g / L Na2HPO4, 0.1-1 g / L MgSO4·7H2O, 0.001-0.01 g / L FeCl3, 0.01-0.5 g / L CaCO3, 0.1-5 g / L silicon source, and 15-20 g / L agar; wherein the silicon source comprises a silicate soil conditioner.

[0070] In some embodiments, the silicate soil conditioner comprises any one or more of attapulgite, montmorillonite, and zeolite.

[0071] The "attapulgite" herein, also known as palygorskite, has a large specific surface area and adsorption capacity, good rheological property and catalytic performance, and at the same time, has ideal colloidal property and heat resistance, and is a rare mineral.

[0072] In some embodiments, the final concentration of the sugar in the screening medium can be specifically any one or a range between any two of 1, 2, 3, 4, 5, 6, 7, 8, 9, 10 g / L. The final concentration of Na2HPO4may be specifically any one or a range between any two of 1, 2, 3, 4, 5 g / L. The final concentration of MgSO4·7H2O can be specifically any one or a range between any two of 0.1, 0.2, 0.4, 0.6, 0.8, 1 g / L. The final concentration of FeCl3may be specifically any one or a range between any two of 0.001, 0.002, 0.003, 0.004, 0.005, 0.006, 0.007, 0.008, 0.009, 0.01 g / L. The final concentration of CaCO3may be specifically any one or a range between any two of 0.01, 0.02, 0.04, 0.06, 0.08, 0.1, 0.12, 0.14, 0.15, 0.2, 0.25, 0.3, 0.35, 0.4, 0.45, 0.5 g / L. The final concentration of the silicon source can be specifically any one or a range between any two of 0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, 1, 1.5, 2, 2.5, 3, 3.5, 4, 4.5, 5 g / L. The final concentration of agar can be specifically any one or a range between any two of 15, 18, 20 g / L.

[0073] Compared with the existing screening medium for silicate bacteria, the screening medium provided by the embodiments of the present application is more conducive to the growth of silicate bacteria, can shorten the culture time of the bacterial strains, improve the screening efficiency, can shorten the screening period of the microorganisms from 4-6 days to 2-4 days, and can also improve the silicic acid dissolution capacity of the screened bacterial strains, thereby providing a new way for effective screening of silicate bacteria.

[0074] In some embodiments, the silicate soil conditioner (attapulgite, montmorillonite or zeolite) has a mesh number of 100-200 meshes, which can be specifically any one or a range between any two of 100, 120, 140, 160, 180, 200 meshes.

[0075] In some embodiments, the sugar includes any one or more of sucrose, glucose and mannitol.

[0076] In some embodiments, the pH of the screening medium is 7.0-7.5, which can be specifically any one or a range between any two of 7.0, 7.1, 7.2, 7.3, 7.4, 7.5.

[0077] In addition, the embodiments of the present application also provide the use of the screening medium as described in any of the preceding embodiments in screening silicate bacteria.

[0078] In some embodiments, the step of screening the silicate bacteria comprises inoculating the candidate strain into the screening medium for culture, and screening to obtain a strain with strong silicate dissolving ability.

[0079] In some embodiments, the culture conditions are the same as those of the strain JH3 described in any of the preceding embodiments, and will not be repeated here.

[0080] The features and performances of the present application are further described in detail below in combination with the embodiments.

[0081] Example 1 Screening of silicate bacteria

[0082] Verification of the effect of different silicon sources on the screening medium:

[0083] This example provides a modified silicate bacteria screening medium, the composition of which is: sucrose 5 g, Na2HPO4 2 g, MgSO4·7H2O 0.5 g, FeCl3 0.005 g, CaCO3 0.1 g, attapulgite 0.5 g (200 mesh), agar 20 g, H2O 1000 mL, pH: 7.0.

[0084] Screening of silicate bacteria based on the modified silicate bacteria screening medium:

[0085] Take 1 g of tobacco rhizosphere soil in the arid area, add it into 99 mL of sterile water in a clean bench, shake well, then add it into 9 mL of sterile water test tube for gradient dilution, respectively diluted into 10 -3 , 10 -4 , 10 -5 , 10 -6 , 10 -7 , 10 -8 , shake well, and then spread on the modified silicate bacteria screening medium, and place in a constant temperature incubator at 32°C for 2 days. The microorganisms grow in the screening medium for 2 days to produce obvious colonies.

[0086] Based on the above screening medium, silicate bacteria with better performance are screened, and are domesticated for multiple times to obtain silicate bacteria with strong silicate dissolving ability.

[0087] On the silicate bacteria screening medium, the strain JH3 forms smooth, round, convex, viscous, elastic, translucent and colorless colonies Figure 1 ). After 48 hours of culture, the average diameter of the colonies of the strain JH3 is 6.83 mm. The transparent hemispherical and viscous bacterial bodies are picked for purification. The colonies after multiple purifications are cultured in large scale, and the silicate dissolving ability is quantitatively determined by silicon molybdenum blue colorimetry. The strain with the strongest silicate dissolving ability is screened by colorimetry.

[0088] Table 1 Silicate dissolving ability of different silicate bacteria

[0089] Strain information Silica-lytic amount range pg / mL Silica-lytic amount pg / mL L5N1 2.08～3.22 2.56 S2-1 4.07～10.19 6.82 JH1 33.27～40.29 36.96 JH2 32.60～37.32 35.65 JH3 44.71～47.78 46.25 JH4 24.08～25.02 24.59 JH5 36.23～41.33 38.48 MJH 35.96～39.73 36.81

[0090] The silicon solubilizing ability of the silicate bacteria JH3 was the strongest, reaching 44.71-47.87 μg / mL, which was 66.83-78.61% higher than the highest silicon solubilizing ability of 26.8 μg / mL reported for silicate bacteria used in agricultural production. JH3 was cultured in an Ashby medium with the following composition: KH2PO4 0.2 g, MgSO4·7H2O 0.2 g, NaCl 0.2 g, CaCO3 0.1 g, attapulgite (200 mesh) 0.5 g, agar 20 g, H2O 1000 mL, pH: 7.0. The bacteria are oligotrophic and can survive more easily than other microorganisms in arid regions and sandy soils.

[0091] Physiological and biochemical characteristics of the screened silicate bacteria JH3 were detected, and the results showed that the silicate bacteria JH3 were negative for oxidase and phenylalanine dehydrogenase activity; the methyl red and V.P. tests were negative; the bacteria could hydrolyze starch, liquefy gelatin, and the indole test was positive, and had poor ability to utilize citrate. JH3 had good ability to utilize glucose, mannitol, sucrose, fructose, lactose, and maltose, but could not utilize raffinose, xylose, and arabinose (Table 2).

[0092] Table 2 Physiological and biochemical characteristics of JH3

[0093] Physiological and biochemical indicators Detection results Physiological and biochemical indicators Detection results Oxidase － Gelatin liquefaction test + Methyl red test － Citrate utilization ability － V.P. test － Indole test + Starch hydrolysis test + Phenylalanine dehydrogenase － Glucose utilization ability + Maltose utilization ability + Mannitol utilization ability + Raffinose utilization ability － Sucrose utilization ability + Xylose utilization ability － Fructose utilization ability + Arabinose utilization ability － Lactose utilization ability +

[0094] The strain Bacillus mucilaginosus subsp. siliceus JH3 was deposited at the China General Microbiological Culture Collection Center on March 9, 2023, and the deposit number is CGMCC No. 26781.

[0095] Based on the above-mentioned improved silicate bacteria screening medium, three groups of control media were set. The control media were roughly the same as the screening medium, and the difference was that the silicon source in the medium was different. The silicon source in the screening medium was attapulgite, and the silicon source in the control screening medium was glass powder, montmorillonite, and zeolite.

[0096] The silicon source in the silicate bacteria screening medium was replaced with attapulgite, glass powder, montmorillonite, and zeolite, respectively, to culture and domesticate the strains. The growth of the silicate bacteria JH3 was observed, and the silicon solubilizing ability of the silicate bacteria JH3 after domestication in different “silicate bacteria screening media” was quantitatively analyzed by the silicon molybdenum blue colorimetric method. It was found that attapulgite as a silicon source could significantly improve the silicon solubilizing ability of the microorganisms, as shown in Table 3. Figure 2

[0097] ​Meanwhile, the loading capacity of glass powder, montmorillonite, zeolite and palygorskite on microorganisms was determined, as shown in Figure 3 With the increase of time, the material's ability to load microorganisms showed a trend of first rising and then falling, and the amount of bacteria loaded by palygorskite was higher at each stage. It can be seen that palygorskite as a silicon source helps to improve the silicon dissolution ability of microorganisms, and the ability of palygorskite to load microorganisms is stronger, which can be used as a strain immobilization material.

[0098] Performance research and function prediction of strain JH3

[0099] After culturing strain JH3 in the medium for 24 hours, the bacterial cells in the logarithmic growth phase were collected by freezing centrifugation (8000 r / min x 15 min) and quick-frozen. The composition of the culture medium is: 2.5 g glucose, 4 g starch, 1 g (NH4)2SO4, 2 g K2HPO4, 0.5 g MgSO4·7H2O, 0.2 g NaCl, 0.005 g FeCl3, and deionized water to 1 L, pH 7.0.

[0100] The strain Bacillus mucilaginosus JH3 was sequenced by second-generation and third-generation whole genome sequencing. The second-generation used the Illumina NovaSeq sequencing platform, and the third-generation used the Oxford Nanopore ONT sequencing platform. The results showed that the genomic DNA of Bacillus mucilaginosus JH3 was circular, without plasmid, with a genome size of 8.59 Mb, a GC content of 58.59%, and a total of 40 ribosomal RNA (rRNA) genes and 156 transfer RNA (tRNA) were detected. The whole genome map is shown in Figure 4 The silicon-dissolving bacteria phylogenetic tree is shown in Figure 5 .

[0101] As shown in Figure 6 , through KEGG analysis, strain JH3 has more genes related to metabolism, providing energy for living organisms to promote their growth. By analyzing the metabolic pathways of the strain, it was found that the strain has more genes related to synthesis enzymes in producing ascorbic acid, producing malic acid, and degrading nicotine, which is helpful for plants to eliminate excess active oxygen caused by drought stress, promote microbial dissolution of minerals, release effective silicon, available phosphorus and other components, and help to provide nutrients for plant growth Figure 7 .

[0102] As shown in Figure 8As shown, using the antiSMASH software, 12 secondary metabolite synthesis gene clusters were predicted, including one polyketide (PKS) type, six non-ribosomal peptide (NRPS) types, two terpene types, and three NRPS and PKS hybrid types. Among these, polyketide (PKS) and non-ribosomal peptide (NRPS) gene clusters (including hybrid types) were abundant, accounting for over 80% of the total gene clusters. One gene cluster showed 100% similarity to a known tridcaptin M gene cluster, while the similarity between two gene clusters ranged from 8% to 60%. Whole-genome analysis indicates that strain JH3 possesses the ability to synthesize secondary metabolites, suggesting good research potential for agricultural fertilizer exploitation.

[0103] Example 3: Effect of applying strain JH3 to tobacco seedlings in pots on promoting growth and drought resistance

[0104] Strain JH3 was added during seedling transplanting. In pot experiments, each pot (21cm×19cm×17cm) contained 3.5kg of soil. An experimental group and a control group were set up. The experimental group received strain JH3 alone, while the control group received only normal base fertilizer and no other fertilizer. JH3 was applied via root drenching. The specific steps were as follows: Strain JH3 was inoculated onto a nitrogen-free culture medium (Assumption medium) and fermented at 35℃ and 180 rpm for 48 hours until the viable cell count in the culture reached 1×10⁻⁶. 8 ~5×10 8 The microbial agent was obtained at a concentration of CFU / mL. It was diluted 50 times before application. The diluted bacterial solution was applied to the roots by irrigation at a ratio of 14.28 mL / kg soil. The same amount of tap water was added as a control, and water was withheld for 15 days.

[0105] Two weeks after the tobacco seedlings had recovered from drought, a drought experiment was conducted to simulate drought in arid regions using a continuous water cut-off method. Before the water cut-off began, the moisture content of the potted plants was adjusted to 90%, and a 15-day drought experiment was conducted. The experimental conditions were identical for both the control group and the case group during the experiment, except for whether or not strain JH3 was added.

[0106] By measuring the fresh weight, dry weight, stem diameter, and leaf area of ​​the above-ground and underground parts of tobacco plants, it was found that the growth indicators of the example group were all better than those of the control group. Figure 9 and Figure 10 As shown in the figure, under drought stress, the fresh weight of tobacco leaves increased by 54.02% compared to the control group. Figure 10 (a) The dry weight of tobacco leaves increased by 100.95% compared to the control group. Figure 10 (b); Tobacco leaf area increased by 132.10% compared to the control group (b). Figure 10 (c); the stem diameter of the tobacco plants increased by 87.07% compared to the control group. Figure 11(d). This indicates that the application of JH3 can effectively promote better plant growth under drought conditions, significantly increase plant biomass, promote leaf growth, promote plant photosynthesis, increase plant stem diameter, and facilitate nutrient transport.

[0107] Figure 11 As shown in Figure a, the available silicon content in the soil first increased and then decreased after the application of strain JH3. After 5 days of drought, the available silicon content in the soil treated with strain JH3 increased by 9.51% compared to the control soil; after 10 days of drought, the available silicon content in the soil treated with strain JH3 increased by 11.8% compared to the control soil; and after 15 days of drought, the available silicon content in the potted soil treated with strain JH3 decreased by 21.42% compared to the control potted soil. The available silicon in the soil decreased significantly, and should be analyzed in conjunction with the available silicon content in the plants. Figure 12 As shown in Figure b, after 15 days of drought, the silicon content in the roots of plants treated with strain JH3 was 427.88% higher than that in the control group (CK), and the silicon content in the leaves of plants treated with strain JH3 was 300.13% higher than that in the control group. Considering that the silicon content inside the plants after applying JH3 was much higher than that in the control group, strain JH3 not only has a high efficiency in dissolving silicon, but also promotes the absorption and utilization of available silicon by plants, prevents water loss in plants under drought stress, and keeps them in a relatively good condition.

[0108] The relative water content, POD, CAT, MDA, and chlorophyll content of leaves were measured. Comparison revealed that the photosynthetic rate in the inoculated group was significantly higher than that in the control group. The malondialdehyde (MDA) content in tobacco leaves of both the inoculated group and the control group was lower than that in the control group. MDA content reflects the degree of peroxidation of plant cell membranes; high MDA content indicates a high degree of peroxidation of plant cell membranes and severe damage to the cell membranes. This suggests that during drought stress, the inoculated group can protect the tobacco plant cell membranes and mitigate the damage caused by drought adversity. Figure 12 As shown, after 15 days of continuous water shortage, the POD content in fresh tobacco leaves increased by 120.75% compared to the control group when strain JH3 was applied. Figure 12 (a) The CAT content in fresh tobacco leaves increased by 283.33% compared to the control group. Figure 12 (b); the MDA content of fresh tobacco leaves decreased by 65.82% compared to the control group. Figure 12 (d); the reducing sugar content increased by 11.43% compared to the control group (d); Figure 13 (c) Figure 14 As shown, chlorophyll a in fresh tobacco leaves increased by 250% compared to the control group; chlorophyll b increased by 88.26% compared to the control group; and the chlorophyll a / b ratio increased by 87.93%. Leaf water content ( Figure 15As shown in the figure, the water content increased significantly by 522.71%. The activities of catalase (CAT) and peroxidase (POD) in the tobacco leaves of the inoculated group were both higher than those in the control group, indicating that functional microbial inoculation can improve the drought resistance of tobacco by enhancing the activity of the antioxidant enzyme POD. POD is an important protective enzyme in plants, participating in the removal of reactive oxygen species produced in plants; the higher its activity, the more beneficial it is for plants to resist drought.

[0109] The strain JH3 of this invention has the ability to enhance the activity of plant antioxidant enzymes, reduce malondialdehyde content, reduce damage to plant cell membranes, increase chlorophyll content in tobacco leaves, and promote plant growth.

[0110] Example 4: Field application effect of strain JH3

[0111] JH3 cells were inoculated into Assumption medium and cultured at 35°C and 180 rpm for 36 hours. The viable cell count was approximately 10. 8 cfu / mL ~10 9 CFU / mL was used to obtain the microbial preparation.

[0112] An example group and a control group were set up. The example group received JH3 (microbial preparation), while the control group received no fertilizer other than normal base fertilizer. The functional JH3 bacterial solution (microbial preparation) was applied by root irrigation. Specifically, the microbial preparation was diluted 50 times and applied to the roots at a ratio of 50 mL / tobacco seedling. The same amount of tap water was added as a control for the field trial.

[0113] After tobacco transplanting, there is a period of mild drought. During the rosette and vigorous growth stages, the water requirement of tobacco plants increases, but rainfall is insufficient, which severely affects plant growth. This experiment added functional microorganism JH3 during the transplanting period and supplemented it during the rosette stage. Tobacco leaves were harvested from the upper and lower parts at maturity and processed into flue-cured tobacco. By measuring the fresh and dry weight of tobacco leaves from different parts, it was found that the fresh and dry weight of all parts in the group treated with functional microorganisms were significantly higher than those in the control group. Furthermore, the upper part of the tobacco leaves in the group was significantly more abundant than that in the control group, indicating that the upper part of the tobacco leaves was more likely to produce high-quality tobacco.

[0114] The results are as follows Figure 15 As shown. Application of silica-degrading bacteria JH3 increased the fresh weight of upper tobacco leaves by 22.17% compared to the control group. Figure 15 (a) The fresh weight of tobacco leaves in the middle section increased by 8.56% compared to the control group. Figure 15 (a) The fresh weight of the lower tobacco leaves decreased by 8.56% compared to the control group. Figure 15 (a) The dry weight of the upper tobacco leaves increased by 23.29% compared to the control group. Figure 15 (b) The dry weight of tobacco leaves in the middle section increased by 8.59% compared to the control group.Figure 15 Middle b), the lower tobacco leaf dry weight decreased by 20.05% (P <0.05) compared with the control group Figure 15 Middle b); the upper tobacco leaf yield increased by 17.78% (P <0.05) compared with the control group Figure 15 Middle c), the middle tobacco leaf yield increased by 11.31% (P <0.05) compared with the control group Figure 15 Middle c), the lower tobacco leaf yield decreased by 9.72% (P <0.05) compared with the control group Figure 16 Middle c); the tobacco plant height increased by 28.86% (P <0.05) compared with the control group Figure 16 Middle d).

[0115] Strain JH3 can promote tobacco growth, increase biomass, increase upper leaf yield, and effectively improve tobacco quality when applied in the field.

[0116] Example 5 Field application effect of JH3 combined with organic fertilizer

[0117] The method for obtaining JH3 bacterial solution is described in Example 3; the organic fertilizer and the JH3 bacterial solution are mixed, wherein the mass of the organic fertilizer accounts for 85% of the bio-organic fertilizer, and the mass of the JH3 bacterial solution accounts for 15% of the mass of the bio-organic fertilizer (the number of bacteria in the bacterial solution should reach 10 8 cfu / mL-10 9 cfu / mL); the mixing method includes: taking out a small amount of organic fertilizer in batches, adding bacterial solution in a sterile environment, mixing and then returning to the original organic fertilizer for mixing, repeating the above steps after mixing, and then performing secondary fermentation, fermenting at room temperature for 7 days, turning over every 18 hours, keeping the moisture content less than 30% after fermentation, and the number of viable bacteria >2×10 7 cfu / g, to obtain bio-organic fertilizer.

[0118] Before transplanting tobacco seedlings, 50 g of bio-organic fertilizer was applied in the tobacco nest, and the conventional treatment was used as the control group, and the results are shown in Figure 16 After the JH3 bacterial solution was combined with the organic fertilizer and applied, the fresh weight of the upper tobacco leaf increased by 195.15% (P <0.05) compared with the control group Figure 16 Middle a), the fresh weight of the middle tobacco leaf increased by 142.41% (P <0.05) compared with the control group Figure 16 Middle a), the fresh weight of the lower tobacco leaf decreased by 31.88% (P <0.05) compared with the control group Figure 16 Middle a); the dry weight of the upper tobacco leaf increased by 183.10% (P <0.05) compared with the control group Figure 16 Middle b), the dry weight of the middle tobacco leaf increased by 144.37% (P <0.05) compared with the control group Figure 16 Middle b), the dry weight of the lower tobacco leaf decreased by 31.98% (P <0.05) compared with the control group Figure 16 Middle b); the yield of the upper tobacco leaf increased by 142.69% (P <0.05) compared with the control group Figure 16The fresh weight of the upper tobacco leaves was increased by 146.07% (middle a) compared with the control group. Figure 16 The fresh weight of the lower tobacco leaves was reduced by 11.02% (middle a) compared with the control group. Figure 17 The dry weight of the upper tobacco leaves was increased by 133.96% (middle b) compared with the control group. Figure 17

[0119] It can be seen that the JH3 and organic fertilizer compound can significantly promote the growth of tobacco, increase the biomass of tobacco plants, increase the yield of upper tobacco leaves, and effectively improve the quality of tobacco.

[0120] Field application effect of strain JH3 and attapulgite compound

[0121] The method for obtaining the JH3 bacterial solution is described in Example 3. The attapulgite and the JH3 bacterial solution are uniformly mixed, wherein the mass of the attapulgite accounts for 85% of the bio-organic fertilizer, and the mass of the JH3 bacterial solution accounts for 15% of the mass of the bio-organic fertilizer (the number of bacteria in the bacterial solution should reach 10 8 cfu / mL-10 9 cfu / mL). The mixing method includes: taking out a small amount of attapulgite in batches, adding the bacterial solution in a sterile environment, mixing and then returning to the original attapulgite for mixing, repeating the above steps after mixing, and then performing secondary fermentation. The fermentation is carried out at room temperature for 7 days, and the fermentation is turned over every 18 hours. After fermentation, the moisture content is less than 30%, and the number of viable bacteria is greater than 10 7 cfu / g. The bio-organic fertilizer is obtained.

[0122] The results are shown in Table 1. Figure 17 The fresh weight of the upper tobacco leaves was increased by 146.07% (middle a) compared with the control group. Figure 17 The fresh weight of the middle tobacco leaves was increased by 54.83% (middle a) compared with the control group. Figure 17 The fresh weight of the lower tobacco leaves was reduced by 11.02% (middle a) compared with the control group. Figure 17 The dry weight of the upper tobacco leaves was increased by 133.96% (middle b) compared with the control group. Figure 17 The dry weight of the middle tobacco leaves was increased by 53.37% (middle b) compared with the control group. Figure 17 The dry weight of the lower tobacco leaves was reduced by 10.65% (middle b) compared with the control group. Figure 17 The yield of the upper tobacco leaves was increased by 83.79% (middle c) compared with the control group. Figure 17 The yield of the middle tobacco leaves was increased by 50.15% (middle c) compared with the control group. Figure 18 The dry weight of the lower tobacco leaves was reduced by 2.87% (middle c) compared with the control group. Figure 18 The height of the tobacco plants was increased by 30.28% (middle d) compared with the control group. Figure 18 The height of the tobacco plants was increased by 30.28% (middle d) compared with the control group.​

[0123] The strain JH3 provided by the application can significantly promote tobacco growth, increase biomass of tobacco plants, increase yield of upper tobacco leaves, and effectively improve tobacco quality when applied in the field in combination with attapulgite.

[0124] Example 7 Field application effect of JH3 combined with attapulgite and organic fertilizer

[0125] The method for obtaining JH3 bacterial solution is described in Example 3; attapulgite and organic fertilizer are mixed at a mass ratio of 2:39, and then the mixture of organic fertilizer-attapulgite and the JH3 bacterial solution are uniformly mixed to prepare a bio-organic fertilizer, wherein the JH3 bacterial solution accounts for 15% of the mass of the bio-organic fertilizer (the number of bacteria in the bacterial solution should reach 10 8 cfu / mL-10 9 cfu / mL), the mixture of organic fertilizer-attapulgite is taken out in small batches, the bacterial solution is added in a sterile environment, and the mixture is mixed again, and the above steps are repeated until the bacterial solution and the mixture are completely mixed, then secondary fermentation is carried out, fermentation is carried out at room temperature for 7 days, and the mixture is turned over every 18 hours, the moisture content after fermentation is less than 30%, the number of effective living bacteria is greater than 107cfu / g, and the bio-organic fertilizer is obtained.

[0126] Before transplanting tobacco seedlings, 50 g of bio-organic fertilizer is applied in the tobacco hole, and a conventional treatment is used as a control group. The application effect is shown in Figure 18 The fresh weight of upper tobacco leaves is increased by 145.91% (a), the fresh weight of middle tobacco leaves is increased by 76.66% (a), the fresh weight of lower tobacco leaves is decreased by 13.46% (a), the dry weight of upper tobacco leaves is increased by 142.68% (b), the dry weight of middle tobacco leaves is increased by 77.89% (b), the dry weight of lower tobacco leaves is decreased by 13.27% (b), the yield of upper tobacco leaves is increased by 83.66% (c), the yield of middle tobacco leaves is increased by 42.59% (c), the yield of lower tobacco leaves is decreased by 23.01% (c), and the height of tobacco plants is increased by 39.43% (d) compared with the control group. Figure 18 Figure 18 Figure 18 Figure 18 Figure 18 Figure 18 Figure 18 ​ ​ ​

[0127] ​​​​​​​​​​The above merely provides the preferred embodiments of the present application, and is not used to limit the present application. For those skilled in the art, the present application can have various modifications and changes. Any modifications, equivalent replacements, improvements, etc. made within the principles and technical scope of the present application shall fall into the scope of the present application.

Claims

1. A Paenibacillus mucilaginosus JH3, characterized in that, The taxonomic name thereof is Bacillus mucilaginosus subsp.siliceus , and the accession number is CGMCC No. 26781.

2. A culture, characterized in that, obtained by culturing the Bacillus mucilaginosus JH3 of claim 1.

3. A bio-agent, characterized by, containing the Bacillus mucilaginosus JH3 of claim 1 and / or the culture of claim 2.

4. Use of the Bacillus mucilaginosus JH3 of claim 1 or the culture of claim 2 or the bioinoculant of claim 3 in the preparation of a fertilizer or a soil conditioner.

5. A fertilizer, characterized by, comprising: a carrier and the Bacillus mucilaginosus JH3 of claim 1 or the culture of claim 2 or the bioinoculant of claim 3; or obtained by fermentation of a mixture of a carrier and the Bacillus mucilaginosus JH3 of claim 1 or the culture of claim 2 or the bioinoculant of claim 3.

6. The fertilizer of claim 5, wherein, The mass ratio of the carrier and the Bacillus mucilaginosus JH3 or the culture or the bioinoculant is 8-9:1-2.

7. The fertilizer of claim 5, wherein, The carrier comprises any one or more of an organic fertilizer and a silicate soil conditioner.

8. The fertilizer of claim 7, wherein, The silicate soil conditioner comprises a combination of any one or more of attapulgite, montmorillonite and zeolite.

9. The fertilizer of claim 7, wherein, When the carrier comprises an organic fertilizer and attapulgite, the mass ratio of the organic fertilizer and attapulgite is 1-2:4-39.

10. The fertilizer according to any one of claims 5 to 9, wherein The fermentation conditions comprise 30-35℃ for 5-7 days.

11. A soil conditioner, characterized in that, containing the Bacillus mucilaginosus JH3 of claim 1 or the culture of claim 2 or the bioinoculant of claim 3 or the fertilizer of any one of claims 5-10.

12. Use of the Bacillus mucilaginosus JH3 of claim 1 or the culture of claim 2 or the bioinoculant of claim 3 or the fertilizer of any one of claims 5-10 or the soil conditioner of claim 11 in any one of: (1) plant cultivation; (2) promoting plant growth or preparing a product for promoting plant growth; (3) improving plant drought resistance or preparing a product for improving plant drought resistance; (4) soil conditioning.

13. Use according to claim 12, characterized in that, The plant comprises any one or more of tobacco, tomato and soybean.

14. A screening medium for desiliconizing bacteria, characterized by, The components and final concentrations of the components comprised therein are as follows: 1-10 g / L of a sugar, 1-5 g / L of Na2HPO4, 0.1-1 g / L of MgSO4·7H2O, 0.001-0.01 g / L of FeCl3, 0.01-0.5 g / L of CaCO3, 0.1-5 g / L of a silicon source and 15-20 g / L of agar; wherein the silicon source is attapulgite.

15. The screening medium of claim 14, wherein, The attapulgite has a mesh size of 100-200 mesh.

16. The screening medium of claim 14, wherein, The sugar comprises any one or more of sucrose, glucose and trehalose.

17. The screening medium of claim 14, wherein, The pH of the screening medium is 7.0-7.

5.

18. Use of the screening medium of any one of claims 14-17 in screening for silicate solubilizing bacteria.

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