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CN-119014402-B - Nano-coated growth-promoting microbial agent, composite growth-promoting microbial agent, preparation method and application thereof

CN119014402BCN 119014402 BCN119014402 BCN 119014402BCN-119014402-B

Abstract

The invention belongs to the technical field of microorganisms, and particularly relates to a nano-coated growth-promoting microbial agent, a composite growth-promoting microbial agent, and a preparation method and application thereof. The nano-coating growth-promoting microbial agent comprises a growth-promoting microbial agent and a nano-coating formed by self-assembling plant-derived polyphenol and soluble multivalent metal ions on the surface of the growth-promoting microbial agent. The composite growth-promoting microbial agent contains the nano-coated growth-promoting microbial agent and prebiotics. The key point of the invention is that the plant-derived polyphenol and the soluble multivalent metal ion are self-assembled on the surface of the growth-promoting microbial agent to form the nano coating, and the interaction exists between the leaves based on the nano coating growth-promoting microbial agent, so that the leaf surface adhesion performance of the plant-derived polyphenol is obviously enhanced, the loss rate of the growth-promoting microbial agent under the flushing of rainwater is effectively reduced, and the survival and colonization of the growth-promoting microbial agent between the leaves are enhanced.

Inventors

  • Zhao Qianbao
  • LIAO YIWEN
  • XU KE
  • ZHU YONGGUAN
  • CAO YUHONG
  • ZHANG LIMEI

Assignees

  • 后农时代(北京)生物科技有限公司

Dates

Publication Date
20260508
Application Date
20240819

Claims (18)

  1. 1. A nano-coated growth-promoting microbial agent is characterized by comprising a growth-promoting microbial agent and a nano-coating formed by self-assembling plant-source polyphenol and soluble multivalent metal ions on the surface of the growth-promoting microbial agent, wherein the mass ratio of the plant-source polyphenol to the soluble multivalent metal ions is (1-10) 1, the growth-promoting microbial agent is at least one selected from klebsiella, paenibacillus polymyxa, bacillus belicus and pseudomonas, the plant-source polyphenol is at least one selected from tannic acid, gallic acid, catechin and apple polyphenol, and the soluble multivalent metal ions are at least one selected from Fe 3+ 、Al 3+ 、Mg 2+ 、Zn 2+ and Ti 4+ .
  2. 2. The nano-coated growth-promoting microbial agent of claim 1, wherein the thickness of the nano-coating is 20-100 nm.
  3. 3. The method for preparing the nano-coated growth-promoting microbial agent according to claim 1 or 2, which is characterized by comprising the step of mixing the growth-promoting microbial agent, plant-derived polyphenol and soluble multivalent metal ions in a solution so as to self-assemble the plant-derived polyphenol and the soluble multivalent metal ions on the surface of the growth-promoting microbial agent to form the nano-coating.
  4. 4. The method of claim 3, wherein the mixing is performed by a method comprising the steps of: S1, uniformly vortex mixing a bacterial suspension of a growth promoting microbial inoculum and a plant source polyphenol solution to obtain a bacterial suspension/plant source polyphenol solution; S2, uniformly mixing the bacterial suspension/plant source polyphenol solution and the soluble multivalent metal ion solution in a vortex manner, and then optionally washing by adopting a PBS buffer solution to obtain the nano-coating growth-promoting bacterial agent.
  5. 5. The method of claim 4, wherein in step S1, the activated growth-promoting bacteria is cultured to a late logarithmic phase, and then the activated growth-promoting bacteria are collected by centrifugation and washed, and then the obtained growth-promoting bacteria are resuspended in deionized water.
  6. 6. The method for preparing a nano-coated growth-promoting bacteria according to claim 5, wherein the number of viable bacteria in the growth-promoting bacteria bacterial suspension is 1x 10 8 ~1×10 9 CFU/mL.
  7. 7. The method for preparing a nano-coated growth-promoting microbial agent according to claim 5, wherein the concentration of the plant-derived polyphenol solution is 5-20 mg/mL.
  8. 8. The method for preparing a nano-coated growth-promoting microbial agent according to claim 5, wherein the ratio of the microbial suspension of the growth-promoting microbial agent to the plant-derived polyphenol solution is 600. Mu.L (25-100. Mu.L).
  9. 9. The method for preparing a nano-coated growth-promoting microbial agent according to claim 5, wherein the vortex mixing time is 10-30 s.
  10. 10. The method for preparing a nano-coated growth-promoting microbial agent according to claim 4, wherein in the step S2, the concentration of the soluble multivalent metal ion solution is 0.5-5 mg/mL.
  11. 11. The method for preparing a nano-coated growth-promoting microbial agent according to claim 10, wherein the ratio of the soluble multivalent metal ion solution to the growth-promoting microbial agent bacterial suspension is (25-100) μl/600 μl.
  12. 12. The method for preparing the nano-coated growth-promoting microbial agent according to claim 4, wherein the vortex mixing time is 10-30 s.
  13. 13. The method for preparing the nano-coated growth-promoting bacteria according to claim 4, wherein the pH value of the PBS buffer solution is 7.2-7.4.
  14. 14. A composite growth promoting microbial agent, wherein the composite growth promoting microbial agent comprises the nano-coated growth promoting microbial agent according to claim 1 or 2 and a prebiotic.
  15. 15. The composite growth promoting microbial agent of claim 14, wherein the mass ratio of the nano-coated growth promoting microbial agent to the prebiotics is 100 (1-100).
  16. 16. The composite probiotic according to claim 14, characterized in that the prebiotic is an alginate.
  17. 17. The composite growth-promoting bacteria of claim 14, wherein the composite growth-promoting bacteria are used in the form of a solution.
  18. 18. The use of a nano-coated growth-promoting microbial agent according to claim 1 or 2 and/or a composite growth-promoting microbial agent according to any one of claims 14 to 17 for promoting plant foliar growth.

Description

Nano-coated growth-promoting microbial agent, composite growth-promoting microbial agent, preparation method and application thereof Technical Field The invention belongs to the technical field of microorganisms, and particularly relates to a nano-coated growth-promoting microbial agent, a composite growth-promoting microbial agent, and a preparation method and application thereof. Background Plant growth promoting bacteria are bacteria capable of promoting plant growth and may colonize on or in plant surface. The plant growth promoting bacteria can promote plant nutrient absorption, induce plant hormone production, decompose harmful substances or resist pathogen infection, thereby realizing direct or indirect growth promoting effect. Today, with increasing population growth and increasing grain demands, abuse of fertilizers and pesticides in agricultural production brings about a series of serious environmental pollution problems, such as soil fertility decrease, water eutrophication and the like. The microbial inoculant prepared by utilizing plant growth promoting bacteria is an important means for replacing chemical fertilizers and realizing sustainable development of agricultural health. Microbial agents need to survive and successfully colonize the surface or interior of crops after application to interact with plants to exert a pro-active effect. Recent studies have progressively revealed that plant-rich leaf area provides a good habitat for microorganisms. Compared with the soil environment, the phyllostatic habitat and flora structure is relatively simple, the leaf area is rich, and the spraying is flexible. How to prepare the foliar microbial agent by utilizing plant growth promoting bacteria is critical to explore an inoculant system which is suitable for the foliar microbial agent, and helps the foliar microbial agent to attach to the leaf of crops and establish symbiotic colonization relation. At present, the research of a foliar microorganism inoculation system is not mature, less research is performed in application, and more research remains in simple spraying of the growth-promoting bacterial suspension. In the leaf surface spraying process, the effective residence time of the traditional bacterial liquid preparation on the leaves of crops is insufficient, and the problems of fogdrop drifting, jumping, rolling, rain washing, decomposition and the like can reduce the effective colonization rate of the growth-promoting bacteria. In addition, the strong hydrophobicity of the waxy layer on the leaf surface and environmental stresses such as drying and ultraviolet rays also present a number of challenges for the survival and colonization of the growth-promoting bacteria. Therefore, there is an urgent need to develop a novel foliar growth promoting agent which has strong adhesion to plant foliar surfaces, has a long residence time between leaves, and is favorable for survival and colonization of growth promoting bacteria between leaves. Disclosure of Invention The invention aims to provide a novel nano-coated growth-promoting microbial agent which has strong adhesion to plant leaf surfaces and long survival time, and can effectively enhance colonization of growth-promoting microbial agents in leaf boundaries. The second purpose of the invention is to provide a preparation method of the nano-coated growth-promoting microbial agent. The invention further aims to provide a composite growth promoting microbial agent. The fourth purpose of the invention is to provide an application of the nano-coated growth-promoting microbial agent and/or the composite growth-promoting microbial agent. Specifically, the nano-coated growth-promoting microbial agent provided by the invention comprises a growth-promoting microbial agent and a nano-coating formed by reacting plant-derived polyphenol and soluble multivalent metal ions on the surface of the growth-promoting microbial agent. In a preferred embodiment, the thickness of the nano-coating is 20-100 nm. In a preferred embodiment, the mass ratio of the plant-derived polyphenol to the soluble polyvalent metal ion is (1-10): 1. In a preferred embodiment, the growth promoting agent is selected from at least one of klebsiella, paenibacillus polymyxa, bacillus beleiensis and pseudomonas. In a preferred embodiment, the plant-derived polyphenol is selected from at least one of tannic acid, gallic acid, catechin and apple polyphenol. In a preferred embodiment, the soluble multivalent metal ion is selected from at least one of Fe 3+、Al3+、Mg2+、Zn2+ and Ti 4+. The preparation method of the nano-coating growth-promoting microbial agent comprises the step of mixing the growth-promoting microbial agent, plant-source polyphenol and soluble multivalent metal ions in a solution, so that the plant-source polyphenol and the soluble multivalent metal ions form a nano-coating on the surface of the growth-promoting microbial agent through self-assembly. In a preferred embodiment, the m