CN-122012365-A - Bacillus bailii biological activity enhancing method and application

Abstract

The invention discloses a bacillus bailii biological activity enhancing method and application, and aims to solve the technical problems that in the prior art, the co-culture synergistic mechanism of bacillus bailii and Paenidrospire polyporus is unknown and the directional enhancement of rhizosphere colonization capability is difficult. The invention adopts the key technical means that the lepidomyces roseus and bacillus bailii are co-cultured and the secreted L-proline is used as a signal molecule to specifically up-regulate the expression of a biomembrane matrix gene epsC/tasA, thereby realizing the directional reinforcement of biomembrane forming capability, remarkably improving the colonization durability and stress tolerance of the strain in rhizosphere, preventing and controlling root-knot nematodes and promoting plant growth effect, and simultaneously enabling the co-culture process to have the adjustability and the product batch stability based on metabolic targets.

Inventors

• YANG LIRONG
• ZHANG JIE
• SONG YAJING
• XIA MINGCONG
• WU CHAO
• DONG QIANQIAN

Assignees

• 河南省农业科学院植物保护研究所

Dates

Publication Date

20260512

Application Date

20260212

Claims (10)

1. 1. Use of L-proline for the preparation of a formulation for enhancing the biofilm formation capacity or/and the bioactivity of bacillus beijerinus (Bacillus velezensis).
2. 2. Use of a trichoderma reesei (Clonostachys rosea) or a fermentation product thereof for enhancing the biofilm formation capacity of bacillus behenii.
3. 3. The use according to claim 1 or 2, wherein the enhancement of the biofilm formation capacity of bacillus belicus is manifested by any one or more of the following: (1) The colonization capability and/or stress tolerance of bacillus beijerinckii in plant rhizosphere are improved; (2) The expression level of the gene epsC and/or tasA related to the synthesis of the bacillus beijerinus biological membrane matrix is up-regulated; (3) Bacillus belicus has improved inhibitory activity on plant parasitic nematodes or has improved plant pro-active effects.
4. 4. The use according to claim 3, wherein the Saccharomycetes roseus is Saccharomycetes roseus (Clonostachys rosea) NF-06 with a preservation number of CGMCC No.16262 and the Bacillus bailii is Bacillus bailii (Bacillus velezensis) YB-1652 with a preservation number of CGMCC No. 36152.
5. 5. A method for enhancing the biological activity of bacillus belicus, which is characterized in that bacillus belicus and tricholomyces roseus are inoculated simultaneously in a liquid culture medium and then co-cultured.
6. 6. The method according to claim 5, wherein the liquid medium is a semisynthetic medium containing soybean meal as a main nitrogen source, and each liter of medium contains 16-24 g of corn flour and soybean meal 8~12 g、MgSO 4 0.3~0.7 g、FeSO 4 ·7H 2 O 0.04~0.06 g、ZnSO 4 ·7H 2 O 0.04~0.06 g.
7. 7. The method according to claim 6, wherein the bacillus bescens is inoculated in the form of a seed solution, the inoculation volume percentage is 1-5%, the trichoderma reesei is inoculated in the form of a spore suspension, the inoculation volume percentage is 1-5%, and the co-culture condition is that the temperature is 25-30 ℃, the rotation speed of a shaking table is 150-200 rpm, and the culture time is 48-72 hours.
8. 8. The method according to claim 7, wherein the biofilm-forming ability or nematode inhibitory activity of the co-culture product is improved by adding a fermentation product of the species trichoderma reesei or a proline standard to the liquid medium to adjust its initial concentration or ratio.
9. 9. A highly active bacillus bailii product, characterized in that it is obtainable by the process according to any one of claims 5 to 8 in the form of a fermentation broth, a concentrate, a lyophilized powder or a formulation with an agriculturally acceptable carrier.
10. 10. Use of the highly active bacillus belgium preparation of claim 9 in any one of the following: (1) Controlling plant parasitic nematodes; (2) Promoting plant growth or enhancing plant stress resistance; (3) Enhance the colonization ability of bacillus belicus in plant rhizosphere.

Description

Bacillus bailii biological activity enhancing method and application Technical Field The invention relates to the technical field of agricultural microorganisms, in particular to a bacillus bailii biological activity enhancing method and application. Background Bacillus bailii (Bacillus velezensis) is used as an important plant rhizosphere growth promoting bacterium, and can show wide application potential in biological control and green agriculture through the ways of secreting antibacterial substances, inducing plant system resistance, promoting nutrient absorption and the like. However, the field application effect is often limited by bottlenecks such as weak rhizosphere colonization capability and insufficient environmental stress tolerance, and particularly when the plant is faced with refractory soil-borne diseases (such as root-knot nematode), the stability and durability of the single strain are difficult to meet the actual production requirements. Related researches show that bacillus forms a biological film with complete structure and rich matrix on the root surface of plants, which is a key precondition for successful colonization and biological control function, and the insufficient formation capacity of the biological film becomes a core factor for restricting the application efficiency. To enhance biocontrol microbial function, microbial co-cultivation strategies are widely explored, i.e. activating silent metabolic pathways or inducing new functional phenotypes through interplay. In the prior art, although a part of bacterial-fungal co-culture system is reported to enhance antibacterial activity, the method has obvious limitations that firstly, most co-culture researches stay in macroscopic phenotype observation (such as expansion of a bacteriostasis zone and increase of fresh weight of plants), analysis on a mechanism layer of key signal molecules and molecular regulation and control channels for driving a synergistic effect is lacking, and secondly, the co-culture process depends on empirical strain mixing or fixed proportion fermentation, directional regulation and control on key rhizosphere adaptive properties (such as biofilm formation) of biocontrol bacteria cannot be carried out due to mechanism cognition deficiency, so that the stability among prepared microbial inoculum batches is poor, the fluctuation of field colonization efficiency is large, and maximization and repeatability of the synergistic effect are difficult to realize. Therefore, a technical scheme with clear mechanism and precise regulation and control is needed in the art, and the biological film forming capability of bacillus beijerinckii can be resolved and directionally reinforced from the molecular interaction level, so that the rhizosphere colonization efficiency and the environmental adaptability of bacillus beijerinckii are systematically improved, and theoretical basis and technical support are provided for developing a high-efficiency and stable microbial biocontrol preparation. The information disclosed in this background section is only for enhancement of understanding of the background of the disclosure and should not be taken as an acknowledgement or any form of suggestion that this information forms the prior art that is well known to a person skilled in the art. Disclosure of Invention The invention provides a bacillus bailii biological activity enhancing method and application, and aims to solve the technical problems that in the prior art, the co-culture synergistic mechanism of bacillus bailii and Paenidrospire polyporus is unknown and the directional enhancement of rhizosphere colonization capability is difficult. The inventor researches find that the combination application of the Paenispira rosea (Clonostachys rosea) NF-06 and the Bacillus bailii (Bacillus velezensis) YB-1652 shows a synergistic effect superior to that of single bacteria in the aspects of preventing and controlling root-knot nematodes and promoting plant growth, and proves the potential of the combination in biocontrol application. Based on the results, the invention discovers that after the co-culture of the Paenibacillus roseus and the Bacillus bailii, the metabolic profile of fungi is changed obviously, and further targeted quantitative analysis identifies that L-proline is a key differential metabolite, the concentration of the differential metabolite presents obvious gradient distribution, namely, the differential metabolite is highest in the culture of the Paenibacillus roseus and is centered in the culture of the Paenibacillus roseus and the metabolite is lowest in the culture of the Bacillus bailii, the gradient distribution shows that the proline and other metabolites produced by the Paenibacillus roseus can be utilized by the Bacillus bailii, functional experiments prove that the proline can enhance the formation of bacterial biological films and up-regulate the expression of matrix genes epsC and tasA, and the research res