Microbial root exudate composition with the function of repairing heavy metal cadmium

Abstract

The present application provides a tea tree microbial root secretion combination preparation with the function of repairing heavy metal cadmium, and relates to the technical field of microbial preparation.The tea tree microbial root secretion combination preparation with the function of repairing heavy metal cadmium comprises the following components in parts by weight: tea tree microbial root secretion combination agent 50-70 parts, stabilizer 10-20 parts, penetrating agent 10-20 parts, and promoting agent 10-20 parts.The present application takes tea tree microbial root secretion as the main active ingredient, combines the advantages of microbial and plant repair, has the ability of efficiently, environmentally-friendly and sustainably repairing heavy metal cadmium contaminated soil, and the stabilizer is added in the preparation to ensure the stability and activity of the preparation in the storage and use process, guarantee that the preparation can still play a good repair effect after long-term storage, and further, the addition of the penetrating agent and the promoting agent can further improve the permeability of the combination preparation, thereby enhancing the repair effect.

Description

Technical Field

[0001] This invention relates to the field of microbial preparation technology, specifically to a combination of tea tree microbial root exudates with the function of repairing heavy metal cadmium. Background Technology

[0002] Cadmium, a heavy metal, has become one of the major threats to soil pollution globally due to its long-term, insidious, and irreversible pollution characteristics. Traditional physical and chemical remediation methods are often costly and may cause secondary pollution. In contrast, bioremediation technologies, especially remediation strategies involving the synergistic effects of plants and microorganisms, show greater potential for environmental friendliness and sustainability.

[0003] Tea plants, as a widely cultivated economic crop, have been proven to tolerate and accumulate a certain amount of cadmium, and the rhizosphere activity of specific microorganisms can further promote the conversion and fixation of cadmium. Therefore, developing a highly efficient remediation compound based on tea plant microbial root exudates is particularly important. Summary of the Invention

[0004] (a) Technical problems to be solved

[0005] To address the shortcomings of existing technologies, this invention provides a combination of tea tree microbial root exudates with the function of remediating heavy metal cadmium, solving the problems that traditional physical and chemical remediation methods are often costly and may cause secondary pollution.

[0006] (II) Technical Solution

[0007] To achieve the above objectives, the present invention is implemented through the following technical solution: a tea tree microbial root exudate combination preparation with the function of repairing heavy metal cadmium, comprising the following components by weight: 50-70 parts of tea tree microbial root exudate combination agent, 10-20 parts of stabilizer, 10-20 parts of penetrant, and 10-20 parts of promoter.

[0008] Preferably, the tea tree microbial root exudate combination preparation with the function of repairing heavy metal cadmium includes the following components in parts by weight: 60 parts of tea tree microbial root exudate combination agent, 20 parts of stabilizer, 10 parts of penetrant, and 10 parts of promoter.

[0009] Preferably, the tea tree microbial root exudate combination agent includes microbial liquid A and root exudate B, wherein microbial liquid A is a mixed liquid of specific Bacillus and other beneficial microorganisms, and root exudate B is an active substance extracted from the root exudate of cadmium-tolerant tea trees.

[0010] Preferably, the stabilizer is a high-molecular-weight polymer stabilizer, which can effectively maintain the stability of the tea plant microbial root exudate formulation during storage and use, prevent chemical reactions or physical separation between components, and ensure that the formulation maintains good activity and efficacy even after long-term storage. This high-molecular-weight polymer stabilizer includes, but is not limited to, polyvinylpyrrolidone (PVP) and polyacrylic acid (PAA), which not only have good stability but also good biocompatibility and are harmless to the soil environment and plant roots.

[0011] Preferably, the penetrant is a surfactant-based penetrant, such as sodium dodecyl sulfate (SDS) or sodium dodecylbenzene sulfonate (SDBS). These penetrants effectively improve the permeability and diffusion of the formulation in the soil, allowing the active ingredients in the formulation to penetrate deeper into the soil more quickly, contacting and reacting with the heavy metal cadmium, thereby improving remediation efficiency.

[0012] Preferably, the promoter is a plant hormone promoter, such as auxin or cytokinin. These promoters can stimulate the growth and metabolic activities of plant roots, enhancing the plant's tolerance and repair capacity to the heavy metal cadmium. Simultaneously, they can also promote the growth and reproduction of tea plant microorganisms, improving the efficiency of microbial degradation and transformation of the heavy metal cadmium.

[0013] Preferably, the preparation method of this tea tree microbial root exudate combination preparation includes the following steps:

[0014] Step 1: Preparation of microbial culture solution A:

[0015] Microbial strains with high adsorption and conversion capacity for cadmium were isolated and screened, and their culture was expanded by liquid submerged fermentation technology to obtain the core component microbial culture A;

[0016] Step 2: Preparation of root exudate B:

[0017] Healthy, cadmium-tolerant tea trees were selected, and root exudates were collected using aseptic culture techniques. The core component, root exudate B, was obtained by purification using ultrafiltration and chromatography techniques.

[0018] Step 3: Mixing, homogenizing, and sterilizing:

[0019] Microbial inoculum A and root exudate B are mixed in an optimized ratio, with appropriate amounts of stabilizer, penetrant and promoter added. After homogenization and sterilization, a stable combination preparation is formed.

[0020] Preferably, in step one, the temperature of the liquid deep fermentation technology is 25-35℃, the pH value is 6.5-7.5, the dissolved oxygen content is 5-10%, the fermentation time is 24-48 hours, and it is carried out in a large fermentation tank.

[0021] Preferably, in step two, the operating conditions of the ultrafiltration and chromatography technology include an ultrafiltration membrane pore size of 0.1-0.5 micrometers, a chromatography column packing material of silica gel or activated carbon, a flow rate controlled at 1-3 ml / min, and a gradient elution method for the chromatography eluent.

[0022] Preferably, in step three, the mixing is carried out under aseptic conditions; the homogenization process uses a high-pressure homogenizer; and the sterilization process uses a high-temperature short-time sterilization method, controlling the temperature at 80-90℃ for 15-30 minutes to kill microorganisms.

[0023] (III) Beneficial Effects

[0024] This invention provides a combination of tea tree microbial root exudates with the function of repairing heavy metal cadmium, which has the following beneficial effects:

[0025] 1. This formulation uses tea tree microbial root exudates as the main active ingredient, combining the advantages of microbial and phytoremediation. It has the ability to remediate cadmium-contaminated soil in a highly efficient, environmentally friendly, and sustainable manner. In addition, a stabilizer is added to the formulation to ensure its stability and activity during storage and use, ensuring that it can still exert a good remediation effect after long-term storage.

[0026] 2. The addition of the penetrant improves the permeability and diffusion of the formulation in the soil, allowing the active ingredients to penetrate deeper into the soil more quickly, come into contact with and react with the heavy metal cadmium, and improve the remediation efficiency. In addition, the addition of the promoter can stimulate the growth and metabolic activities of plant roots, enhance the plant's tolerance and remediation ability to the heavy metal cadmium, and at the same time promote the growth and reproduction of microorganisms, thereby improving the degradation and transformation efficiency of the heavy metal cadmium by microorganisms.

[0027] 3. The preparation method of the present invention is simple and easy to implement. The core component, root exudate B, is obtained by purifying it using ultrafiltration and chromatography technology, which ensures the purity and activity of the active ingredient. At the same time, the homogenization and short-time sterilization of the preparation are ensured by using a high-pressure homogenizer and high-temperature short-time sterilization method.

[0028] In summary, the tea tree microbial root exudate combination preparation with the function of remediating heavy metal cadmium provided by the present invention has broad application prospects and important environmental significance in the field of remediation of heavy metal cadmium contaminated soil. Attached Figure Description

[0029] Figure 1 This is a schematic diagram of the preparation method of the combination formulation of the present invention. Detailed Implementation

[0030] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0031] Example 1:

[0032] This invention provides a tea tree microbial root exudate combination preparation with the function of repairing heavy metal cadmium, comprising the following components by weight: 50 parts of tea tree microbial root exudate combination agent, 10 parts of stabilizer, 20 parts of penetrant, and 20 parts of promoter.

[0033] Specifically, the tea tree microbial root exudate combination agent includes microbial inoculum A and root exudate B. Microbial inoculum A is a mixed inoculum of specific Bacillus and other beneficial microorganisms, and root exudate B is an active substance extracted from the root exudate of cadmium-tolerant tea trees.

[0034] Secondly, the stabilizer is a high molecular weight polymer stabilizer, specifically polyvinylpyrrolidone; the penetrant is a surfactant penetrant, specifically sodium dodecyl sulfate; and the promoter is a plant hormone promoter, specifically auxin.

[0035] like Figure 1 As shown, this embodiment of the invention also provides a method for preparing the tea tree microbial root exudate combination formulation, including the following steps:

[0036] Step 1: Preparation of microbial culture solution A:

[0037] Microbial strains with high adsorption and conversion capacity for cadmium were isolated and screened, and their culture was expanded by liquid submerged fermentation technology to obtain the core component microbial culture A;

[0038] The liquid deep fermentation technology is carried out at a temperature of 25°C, a pH of 6.5, a dissolved oxygen content of 5%, and a fermentation time of 24 hours in a large fermentation tank.

[0039] Step 2: Preparation of root exudate B:

[0040] Healthy, cadmium-tolerant tea trees were selected, and root exudates were collected using aseptic culture techniques. The core component, root exudate B, was obtained by purification using ultrafiltration and chromatography techniques.

[0041] The operating conditions of the ultrafiltration and chromatography technology include an ultrafiltration membrane pore size of 0.1 micrometers, a chromatography column packing material of silica gel, a flow rate controlled at 1 ml / min, and a gradient elution method for the chromatography eluent.

[0042] Step 3: Mixing, homogenizing, and sterilizing:

[0043] Microbial inoculum A and root exudate B are mixed in an optimized ratio, with appropriate amounts of stabilizer, penetrant and promoter added. After homogenization and sterilization, a stable combined preparation is formed.

[0044] The mixing is carried out under aseptic conditions; the homogenization process uses a high-pressure homogenizer; and the sterilization process uses a high-temperature short-time sterilization method, controlling the temperature at 80°C for 15 minutes to kill microorganisms.

[0045] Example 2:

[0046] The difference between this embodiment and Embodiment 1 is that the tea tree microbial root exudate combination preparation with the function of repairing heavy metal cadmium includes the following components by weight: 60 parts of tea tree microbial root exudate combination agent, 20 parts of stabilizer, 10 parts of penetrant, and 10 parts of promoter.

[0047] Secondly, the stabilizer is a high molecular weight polymer stabilizer, specifically polyacrylic acid; the penetrant is a surfactant penetrant, specifically sodium dodecylbenzenesulfonate; and the promoter is a plant hormone promoter, specifically cytokinin.

[0048] Regarding the preparation method of the tea tree microbial root exudate combination preparation, in step one, the temperature of the liquid deep fermentation technology is 30℃, the pH value is 7.0, the dissolved oxygen content is 8%, the fermentation time is 36 hours, and it is carried out in a large fermentation tank.

[0049] In step two, the operating conditions of the ultrafiltration and chromatography technology include an ultrafiltration membrane pore size of 0.3 micrometers, a chromatography column packing material of activated carbon, a flow rate controlled at 2 ml / min, and a gradient elution method for the chromatography eluent.

[0050] In step three, the mixing is carried out under aseptic conditions; the homogenization process uses a high-pressure homogenizer; and the sterilization process uses a high-temperature short-time sterilization method, controlling the temperature at 85°C for 20 minutes to kill microorganisms.

[0051] Example 3:

[0052] The difference between this embodiment and Embodiment 1 is that the tea tree microbial root exudate combination preparation with the function of repairing heavy metal cadmium includes the following components by weight: 70 parts of tea tree microbial root exudate combination agent, 10 parts of stabilizer, 10 parts of penetrant, and 10 parts of promoter.

[0053] Secondly, the stabilizers are high molecular weight polymer stabilizers, specifically polyvinylpyrrolidone and polyacrylic acid; the penetrants are surfactant penetrants, specifically sodium dodecyl sulfate and sodium dodecylbenzene sulfonate; and the promoters are plant hormone promoters, specifically auxins and cytokinins.

[0054] Regarding the preparation method of the tea tree microbial root exudate combination preparation, in step one, the temperature of the liquid deep fermentation technology is 35℃, the pH value is 7.5, the dissolved oxygen content is 10%, the fermentation time is 48 hours, and it is carried out in a large fermentation tank.

[0055] In step two, the operating conditions of the ultrafiltration and chromatography technology include an ultrafiltration membrane pore size of 0.5 micrometers, a chromatography column packing material of activated carbon, a flow rate controlled at 3 ml / min, and a gradient elution method for the chromatography eluent.

[0056] In step three, the mixing is carried out under aseptic conditions; the homogenization process uses a high-pressure homogenizer; and the sterilization process uses a high-temperature short-time sterilization method, controlling the temperature at 90°C for 30 minutes to kill microorganisms.

[0057] Comparative example:

[0058] This comparative example aims to compare the effectiveness of a common microbial remediation agent, which does not contain the tea tree microbial root exudate compound, in the remediation of cadmium-contaminated soil. This common microbial remediation agent contains only common microbial strains and a small amount of nutrients, and does not contain the core ingredient of this invention, the tea tree microbial root exudate compound.

[0059] The specific implementation plan is as follows: Ordinary microbial remediation agents are prepared using conventional methods and directly applied to soil contaminated with the heavy metal cadmium. The cadmium removal rate and microbial activity in the soil are observed regularly to assess the remediation effect.

[0060] Experimental example:

[0061] The performance of the combined formulations prepared in Examples 1, 2, 3 and the comparative examples was tested, and the results are shown in the table below:

[0062]

[0063] The experimental data above show that the combined preparations of tea tree microbial root exudates prepared in Examples 1, 2, and 3 all exhibited high cadmium removal rates and microbial activity in the remediation of cadmium-contaminated soil. Among them, Example 2 showed the highest cadmium removal rate, reaching 95.6%, and also the highest microbial activity, indicating that this combined preparation has significant advantages in the remediation of cadmium-contaminated soil.

[0064] In contrast, while the conventional microbial remediation agents in the comparative examples also exhibited some cadmium removal rate and microbial activity, their levels were significantly lower than those of the combined formulations prepared in Examples 1, 2, and 3. This fully demonstrates the important role of tea tree microbial root exudate combination agents in the remediation of cadmium-contaminated soil.

[0065] To further explore the mechanism of tea tree microbial root exudate compound in the remediation of cadmium-contaminated soil, we conducted in-depth analysis and research. The results showed that the microbial inoculum A and root exudate B in the tea tree microbial root exudate compound can work synergistically to reduce the cadmium content in the soil through multiple mechanisms such as adsorption, transformation, and degradation. Simultaneously, the addition of stabilizers, penetrants, and promoters can further improve the stability and permeability of the compound, thereby enhancing its remediation effect.

[0066] In summary, the tea tree microbial root exudate compound preparation with cadmium remediation function provided by this invention has significant advantages and broad application prospects in the remediation of cadmium-contaminated soil. By optimizing the preparation process and formulation of the compound preparation, its remediation effect can be further improved, providing new ideas and methods for the treatment of heavy metal-contaminated soil.

[0067] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A tea tree microbial root exudate preparation with the function of repairing heavy metal cadmium, characterized in that: It includes the following components by weight: 50-70 parts of tea tree microbial root exudate compound, 10-20 parts of stabilizer, 10-20 parts of penetrant, and 10-20 parts of promoter; The tea tree microbial root exudate combination agent includes microbial liquid A and root exudate B. Microbial liquid A is a mixed liquid of specific Bacillus and other beneficial microorganisms, and root exudate B is an active substance extracted from the root exudate of cadmium-tolerant tea trees.

2. The tea tree microbial root exudate combination preparation with the function of repairing heavy metal cadmium as described in claim 1, characterized in that: It includes the following components by weight: 60 parts of tea tree microbial root exudate compound, 20 parts of stabilizer, 10 parts of penetrant, and 10 parts of promoter.

3. The tea tree microbial root exudate combination preparation with the function of repairing heavy metal cadmium as described in claim 1 or 2, characterized in that: The stabilizer is a polymer stabilizer, which includes, but is not limited to, polyvinylpyrrolidone and polyacrylic acid.

4. The tea tree microbial root exudate combination preparation with the function of repairing heavy metal cadmium as described in claim 1 or 2, characterized in that: The penetrant is a surfactant-type penetrant, which includes, but is not limited to, sodium dodecyl sulfate and sodium dodecylbenzene sulfonate.

5. The tea tree microbial root exudate combination preparation with the function of repairing heavy metal cadmium as described in claim 1 or 2, characterized in that: The promoter is a plant hormone promoter, which includes, but is not limited to, auxin and cytokinin.

6. The tea tree microbial root exudate combination preparation with the function of repairing heavy metal cadmium as described in claim 1, characterized in that: The preparation method of this tea tree microbial root exudate compound includes the following steps: Step 1: Preparation of microbial culture solution A: Microbial strains with high adsorption and conversion capacity for cadmium were isolated and screened, and their culture was expanded by liquid submerged fermentation technology to obtain the core component microbial culture A; Step 2: Preparation of root exudate B: Healthy, cadmium-tolerant tea trees were selected, and root exudates were collected using aseptic culture techniques. The core component, root exudate B, was obtained by purification using ultrafiltration and chromatography techniques. Step 3: Mixing, homogenizing, and sterilizing: Microbial inoculum A and root exudate B are mixed in an optimized ratio, with appropriate amounts of stabilizer, penetrant and promoter added. After homogenization and sterilization, a stable combination preparation is formed.

7. The tea tree microbial root exudate combination preparation with the function of repairing heavy metal cadmium as described in claim 6, characterized in that: In step one, the temperature of the liquid deep fermentation technology is 25-35℃, the pH value is 6.5-7.5, the dissolved oxygen content is 5-10%, the fermentation time is 24-48 hours, and it is carried out in a large fermentation tank.

8. The tea tree microbial root exudate combination preparation with the function of repairing heavy metal cadmium as described in claim 6, characterized in that: In step two, the operating conditions of the ultrafiltration and chromatography technology include an ultrafiltration membrane pore size of 0.1-0.5 micrometers, a chromatography column packing material of silica gel or activated carbon, a flow rate controlled at 1-3 ml / min, and a gradient elution method for the chromatography eluent.

9. The tea tree microbial root exudate combination preparation with the function of repairing heavy metal cadmium as described in claim 6, characterized in that: In step three, the mixing is carried out under aseptic conditions; the homogenization process uses a high-pressure homogenizer; and the sterilization process uses a high-temperature short-time sterilization method, controlling the temperature at 80-90℃ for 15-30 minutes to kill microorganisms.

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