Microbial bactericide and preparation method thereof

Abstract

The invention relates to the field of bactericides, and particularly discloses a microbial bactericide and a preparation method thereof. The microbial bactericide is prepared from the following raw material components: 40 to 45 parts of microbial source fermentation liquor; 50 to 60 parts of a carrier; 2-3 parts of a dispersing aid; 3-5 parts of a surfactant; 0.5 to 1 part of a synergist; microbial sources in the microbial source fermentation liquor comprise bacillus, trichoderma harzianum, trichoderma viride and pythium oligandrum according to the weight ratio of 50: (20-25): (10-15): 10, and the carrier comprises at least two of sodium lactate, calcium sulfate and manganese sulfate; the preparation method comprises the following steps: I, activating and culturing a microbial source; iI, preparing microbial source fermentation liquor; and III, preparing the microbial bactericide. The composition disclosed by the invention has high bactericidal ability, high stability and long-acting bactericidal ability, the prevention and treatment effect can be not lower than 71.5%, and the suspension rate is not lower than 97.85%.

Description

Technical Field

[0001] The present application relates to the technical field of fungicides, and in particular to a microbial fungicide and a preparation method thereof. Background Art

[0002] Microbial fungicides have important application value in the fields of medical treatment, food processing and environmental disinfection. In recent years, with the global overuse of antibiotics, the problem of microbial resistance has become increasingly serious, and the effect of traditional chemical synthetic fungicides has gradually weakened and cannot meet modern needs. At the same time, the biochemical industry continues to explore antibacterial ingredients from natural sources. These ingredients have attracted much attention due to their lower toxicity and higher safety, and are regarded as an important way to replace traditional fungicides.

[0003] In order to improve the effectiveness of microbial fungicides, the industry usually takes a variety of measures. Common methods include using natural active substances such as plant extracts, animal extracts and microbial metabolites to prepare fungicides. In addition, various stabilizers such as antioxidants, chelating agents and preservatives are added to extend the shelf life of active substances. At the same time, in order to ensure the uniform distribution of active substances, dispersants are added to enhance the degree of dispersion, and different types of surfactants are used to improve the diffusion performance of fungicides. Sometimes synergists are introduced to further improve the bactericidal efficiency.

[0004] Although the above methods have solved some of the problems to a certain extent, existing microbial fungicides still have significant shortcomings. They are mainly manifested in low activity, poor stability, and easy degradation. These problems seriously affect their reliability and durability in practical applications. Therefore, how to improve the stability and long-term effectiveness of microbial fungicides has become a key technical problem that needs to be solved urgently in this field. Summary of the invention

[0005] In order to solve the above technical problems, the present application provides a microbial fungicide and a preparation method thereof.

[0006] In the first aspect, the present application provides a microbial fungicide, in which the raw materials used include the following components, by weight: 40-45 parts of microbial source fermentation broth; 50-60 parts of a carrier; 2-3 parts of a dispersant; 3-5 parts of a surfactant; and 0.5-1 part of a synergist. The microbial source in the microbial source fermentation broth includes Bacillus, Trichoderma harzianum, Trichoderma viride and Pythium oligandrum in a weight ratio of 50:(20-25):(10-15):10, and the carrier includes at least two of sodium lactate, calcium sulfate and manganese sulfate.

[0007] By adopting the above technical scheme, the present application utilizes a combination of Bacillus, Trichoderma harzianum, Trichoderma viride and Pythium oligandrum as microbial sources, and gives full play to their respective bactericidal effects. Among them, Bacillus can form spores with strong resistance to stress and inhibit a variety of plant pathogens. Trichoderma harzianum has a wide range of anti-pathogenic activity and can produce a variety of antibacterial substances. Trichoderma viride can produce a variety of enzymes and antibacterial substances and has a strong biological control potential. Pythium oligandrum, as an oomycete, can parasitize on the spores and hyphae of pathogens, thereby reducing the occurrence of diseases. The present application compounds the above-mentioned multiple microbial source substances. Compared with the bactericidal effect of using only one or two microbial sources, the bactericidal effect can be guaranteed to be improved to a certain extent while reducing the dosage. The diameter of the inhibition zone of the obtained microbial fungicide after dilution ten times is not less than 16.2 mm.

[0008] The present application utilizes at least two of sodium lactate, calcium sulfate and manganese sulfate as carriers, giving full play to the good water solubility and biocompatibility of sodium lactate, and the porous structure of calcium sulfate to adsorb the main bactericidal active substances in the microbial fungicide. Manganese sulfate has both good water solubility and excellent active metal ion providing ability. The compounding of at least two of the three can greatly improve the stability and long-term effect of the microbial fungicide.

[0009] In summary, the microbial source of the present application has a highly efficient bactericidal effect, the carrier has good adsorption and protection capabilities, and the system is also doped with dispersants, surfactants and enhancers. The various substances cooperate with each other to give full play to the synergistic effect, and finally obtain a microbial fungicide with high bactericidal ability, high stability and long-term bactericidal ability. In the experiment of preventing and controlling diseases, the prevention and control effect can reach not less than 71.5%, and the suspension rate is not less than 97.85%.

[0010] Preferably, the Bacillus includes Bacillus amyloliquefaciens and Bacillus thuringiensis.

[0011] Preferably, the weight ratio of the Bacillus amyloliquefaciens to the Bacillus thuringiensis is 5:(2-3).

[0012] By adopting the above technical scheme, the Bacillus of the present application includes Bacillus amyloliquefaciens and Bacillus thuringiensis, which give full play to the different bactericidal mechanisms and action ranges of these two strains. Bacillus amyloliquefaciens can form spores with strong stress resistance and effectively inhibit a variety of plant pathogens, while Bacillus thuringiensis has a broad spectrum of antibacterial activity and can target more bacteria and fungal diseases. This combination not only improves the overall bactericidal effect of the microbial fungicide, but also ensures efficient and stable antibacterial performance while reducing the dosage.

[0013] Preferably, the auxiliary dispersant includes one or more of sodium lignin sulfonate, phenethylphenol polyoxyethylene ether, quinoline copper and polycarboxylate dispersants.

[0014] By adopting the above technical scheme, the present application selects one or more of sodium lignin sulfonate, phenethylphenol polyoxyethylene ether, quinoline copper and polycarboxylate dispersant as co-dispersants, which can effectively improve the dispersibility of the microbial fungicide and ensure that each component is evenly distributed in the system, thereby improving the overall stability and effect of the fungicide. Specifically, sodium lignin sulfonate has excellent dispersibility and can prevent particle aggregation, phenethylphenol polyoxyethylene ether can enhance water solubility and wettability, quinoline copper helps to improve antibacterial properties, and polycarboxylate dispersants can further increase the dispersion effect and stability. The combined use of these co-dispersants allows the microbial fungicide to show better uniformity and durability in practical applications.

[0015] Preferably, the dispersant aid comprises sodium lignin sulfonate, quinoline copper and a polycarboxylate dispersant in a weight ratio of 3:(1-1.5):(1.5-1.8).

[0016] By adopting the above technical solution, sodium lignin sulfonate, quinoline copper and polycarboxylate dispersant in the dispersant are mixed in a specific proportion, which can significantly improve the uniform dispersion of the microbial fungicide, ensure that the components are fully mixed, and avoid the problem of poor sterilization effect in some areas due to uneven dispersion.

[0017] Preferably, the carrier comprises sodium lactate, calcium sulfate and manganese sulfate in a weight ratio of 20:(8-10):5.

[0018] By adopting the above technical scheme, the present application utilizes sodium lactate, calcium sulfate and manganese sulfate in a specific proportion as carriers, giving full play to the advantages of each component, and compounding them in a weight ratio of 20:(8-10):5, which can better exert synergistic effects, improve the overall stability and long-term effectiveness of the microbial fungicide, and enable it to exhibit more excellent performance in practical applications.

[0019] Preferably, the surfactant includes sodium dodecylbenzene sulfonate and coconut oil fatty acid diethanolamide.

[0020] By adopting the above technical scheme, the present application utilizes sodium dodecylbenzene sulfonate with strong hydrophilicity and detergency, which helps to improve the overall stability and uniformity of the solution; coconut oil fatty acid diethanolamide has good emulsification ability and skin friendliness, which can further improve the physical properties of the preparation, making it easier to apply and maintain its effective effect for a longer time in the environment, and can effectively promote the mixing of microbial source fermentation liquid with other components, improve the adhesion and diffusion performance of the fungicide on the target surface, thereby enhancing its bactericidal effect.

[0021] In a second aspect, the present application also provides a method for preparing a microbial fungicide, comprising the following steps: I. Activating and culturing a microbial source: activating the microbial source, and then inoculating and culturing the microbial source at an inoculation rate of 8-10% to obtain a microbial source fermentation liquid; II. preparing microbial source fermentation broth; III. Preparation of microbial fungicide: The microbial source fermentation liquid obtained in step II is mixed with a carrier, stirred until the system is uniform and then dried, then mixed with a dispersant, a surfactant and a synergist, and crushed to obtain a microbial fungicide.

[0022] Preferably, in step I, the culture temperature of Bacillus is 28-32°C, and the culture temperature of Trichoderma harzianum, Trichoderma viride and Pythium oligandrum is 25-28°C.

[0023] By adopting the above technical solution, the preparation method not only simplifies the process flow and improves production efficiency, but also effectively ensures the quality consistency of the microbial fungicide. Specifically, by activating the microbial source and accurately controlling the inoculation amount, the effective reproduction and synergy of each microbial population during the fermentation process are ensured, thereby improving the bactericidal effect of the final product. In addition, by fully mixing and drying the microbial source fermentation liquid with a specific proportion of the carrier, and then blending it with other additives, the active ingredients are more evenly distributed throughout the system, enhancing the overall stability and long-term effectiveness of the fungicide.

[0024] The present application also optimizes the culture conditions of the microbial source, specifically, Bacillus is cultured at 28-32°C, and Trichoderma harzianum, Trichoderma viride and Oligandrum pythium are cultured at 25-28°C. This specific temperature range is not only conducive to the optimal growth and reproduction of each microbial population, but also effectively promotes them to produce more active substances, thereby improving the bactericidal effect and stability of the final microbial fungicide. For example, Bacillus can better form spores with strong stress resistance within this temperature range, increasing its adaptability to the environment; Trichoderma harzianum and Trichoderma viride can more effectively produce antibacterial substances under suitable low temperature conditions and enhance the bactericidal efficacy; and Oligandrum pythium also exhibits higher parasitic ability and anti-pathogenic effects within this temperature range. These optimization measures make the entire fungicide system more efficient and stable, and improve its reliability and durability in practical applications.

[0025] In summary, this application has the following beneficial technical effects: 1. The present application uses a compound of Bacillus, Trichoderma harzianum, Trichoderma viride and Pythium oligandrum to give full play to the synergistic effect of each microbial source, significantly improves the bactericidal effect of the microbial fungicide, and the diameter of the inhibition zone after dilution ten times is not less than 16.2 mm. At least two of sodium lactate, calcium sulfate and manganese sulfate are used as carriers to enhance the adsorption and protection capacity of active substances, greatly improve the stability and long-term effect of the microbial fungicide, and can achieve a control effect of not less than 71.5% in the experiment of disease prevention and control, and the suspension rate is not less than 97.85%; 2. The preparation method of the present application not only simplifies the process flow and improves production efficiency, but also effectively ensures the quality consistency of the microbial fungicide. By activating the microbial source and accurately controlling the inoculation amount, it ensures the effective reproduction and synergy of each microbial population during the fermentation process, thereby improving the bactericidal effect and long-term effectiveness of the final product. DETAILED DESCRIPTION

[0026] Material Source Raw materials used in this application: Bacillus licheniformis, deposited by China Pharmaceutical Microbiological Culture Collection Center, deposit number CPCC 140347: Trichoderma harzianum, deposited in China Industrial Microbiological Culture Collection Center, deposit number CICC 13010; Trichoderma viride, deposited in China Industrial Microbiological Culture Collection Center, deposit number CICC 13004; Pythium oligandrum is deposited in China Type Culture Collection of Wuhan University, with the accession number CCTCC 2022710; Bacillus amyloliquefaciens, deposited in Beijing Center for Biological Collection, deposit number CICC 10035; Bacillus thuringiensis, deposited in Shanghai Biotechnology Collection Center, with the deposit number SHBCC D80131.

[0027] The present application is further described in detail below in conjunction with embodiments and comparative examples.

[0028] Example 1.1 A method for preparing a microbial bactericide comprises the following steps: I. Activation and cultivation of microbial sources: The microbial sources (Bacillus licheniformis, Trichoderma harzianum, Trichoderma viride and Pythium oligandrum in a weight ratio of 50:20:15:10) were placed at room temperature for 24 hours, and then transferred to different test tubes for slant culture at a temperature of 28° C. for 48 hours, and then inoculated into PDA medium at a 10% inoculum amount for culture at a temperature of 25° C., a culture speed of 170 min, and a culture time of 72 hours to obtain liquid seeds; II. Preparing microbial fermentation liquid: the liquid seeds obtained in step I are transferred into a solid fermentation medium containing kainic acid, and solid fermentation is performed at a temperature of 32° C. for 72 hours to obtain a solid fermentation product, and the solid fermentation product is added to twice the weight of sterile water and soaked for 20 minutes, and shaken at 180 r / min for 20 minutes, and the solid residue is filtered through gauze to obtain a microbial fermentation liquid; III. Preparation of microbial fungicide: 40 g of the microbial source fermentation liquid obtained in step II is mixed with 60 g of a carrier (30 g of sodium lactate and 30 g of calcium sulfate), stirred until the system is uniform and then spray-dried, then blended with 2 g of a dispersant (phenylethylphenol polyoxyethylene ether), 5 g of a surfactant (sodium dodecylbenzene sulfonate) and 0.5 g of a synergist (isomeric tridecanol), and crushed to 100 mesh to obtain a microbial fungicide.

[0029] Example 1.2 A method for preparing a microbial bactericide comprises the following steps: I. Activation and cultivation of microbial sources: The microbial sources (Bacillus licheniformis, Trichoderma harzianum, Trichoderma viride and Pythium oligandrum in a weight ratio of 50:25:10:10) were placed at room temperature for 24 hours, and then transferred to different test tubes for slant culture at a temperature of 28° C. for 48 hours, and then inoculated into PDA medium at a 10% inoculum amount for culture at a temperature of 25° C., a culture speed of 170 min, and a culture time of 72 hours to obtain liquid seeds; II. Preparing microbial fermentation liquid: the liquid seeds obtained in step I are transferred into a solid fermentation medium containing kainic acid, and solid fermentation is performed at a temperature of 32° C. for 72 hours to obtain a solid fermentation product, and the solid fermentation product is added to twice the weight of sterile water and soaked for 20 minutes, and shaken at 180 r / min for 20 minutes, and the solid residue is filtered through gauze to obtain a microbial fermentation liquid; III. Preparation of microbial fungicide: 45 g of the microbial source fermentation liquid obtained in step II is mixed with 50 g of a carrier (10 g of sodium lactate, 15 g of manganese sulfate and 25 g of calcium sulfate), stirred until the system is uniform and then spray-dried, then blended with 3 g of a dispersant (phenylethylphenol polyoxyethylene ether), 3 g of a surfactant (sodium dodecylbenzene sulfonate) and 1 g of a synergist (isomeric tridecanol), and crushed to 100 mesh to obtain a microbial fungicide.

[0030] Example 2.1 A method for preparing a microbial fungicide, which is different from Example 1.1 in that: in step I, the culture temperature of Bacillus licheniformis is 32°C, and the culture temperature of Trichoderma harzianum, Trichoderma viride and Pythium oligandrum is 25°C, and the rest is the same as Example 1.1.

[0031] Example 2.2 A method for preparing a microbial fungicide, which is different from Example 1.1 in that: in step I, the culture temperature of Bacillus licheniformis, Trichoderma harzianum, Trichoderma viride and Pythium oligandrum is 28°C, and the rest is the same as Example 1.1.

[0032] Example 3.1 A method for preparing a microbial fungicide, which is different from that of Example 1.1 in that: in step I, Bacillus licheniformis is replaced by Bacillus amyloliquefaciens, and the rest is the same as that of Example 1.1.

[0033] Example 3.2 A method for preparing a microbial fungicide, which is different from that of Example 1.1 in that: in step I, Bacillus licheniformis is replaced by Bacillus thuringiensis, and the rest is the same as that of Example 1.1.

[0034] Example 3.3 A method for preparing a microbial fungicide, which is different from that of Example 1.1 in that: in step I, Bacillus licheniformis is replaced by Bacillus amyloliquefaciens and Bacillus thuringiensis in a weight ratio of 5:2, and the rest is the same as that of Example 1.1.

[0035] Example 3.4 A method for preparing a microbial fungicide, which is different from that of Example 1.1 in that: in step I, Bacillus licheniformis is replaced by Bacillus amyloliquefaciens and Bacillus thuringiensis in a weight ratio of 5:3, and the rest is the same as that of Example 1.1.

[0036] Example 3.5 A method for preparing a microbial fungicide, which is different from that of Example 1.1 in that: in step I, 50 wt% of Bacillus licheniformis is replaced with Bacillus amyloliquefaciens, and the rest is the same as that of Example 1.1.

[0037] Example 3.6 A method for preparing a microbial fungicide, which is different from that of Example 1.1 in that: in step I, 50 wt% of Bacillus licheniformis is replaced by Bacillus thuringiensis, and the rest is the same as that of Example 1.1.

[0038] Example 4.1 A method for preparing a microbial fungicide, which is different from that of Example 1.1 in that: in step III, all phenethylphenol polyoxyethylene ether is replaced by sodium lignin sulfonate, and the rest is the same as that of Example 1.1.

[0039] Example 4.2 A method for preparing a microbial fungicide, which is different from Example 1.1 in that: in step III, all phenethylphenol polyoxyethylene ether is replaced by quinoline copper, and the rest is the same as Example 1.1.

[0040] Example 4.3 A method for preparing a microbial bactericide is different from that of Example 1.1 in that: in step III, all phenethylphenol polyoxyethylene ether is replaced by a polycarboxylate dispersant, and the rest is the same as that of Example 1.1.

[0041] Example 5.1 A method for preparing a microbial fungicide, which is different from Example 1.1 in that: in step III, all phenethylphenol polyoxyethylene ether is replaced with 1.03g sodium lignin sulfonate, 0.34g quinoline copper and 0.63g polycarboxylate dispersant, and the rest is the same as Example 1.1.

[0042] Example 5.2 A method for preparing a microbial fungicide, which is different from Example 1.1 in that: in step III, all phenethylphenol polyoxyethylene ether is replaced with 1g sodium lignin sulfonate, 0.5g quinoline copper and 0.5g polycarboxylate dispersant, and the rest is the same as Example 1.1.

[0043] Example 6.1 A method for preparing a microbial fungicide, which is different from Example 1.1 in that: in step III, the carrier is 36.4g sodium lactate, 14.5g calcium sulfate and 9.1g manganese sulfate, and the rest is the same as Example 1.1.

[0044] Example 6.2 A method for preparing a microbial fungicide, which is different from Example 1.1 in that: in step III, the carrier is 34.3g sodium lactate, 17.1g calcium sulfate and 8.6g manganese sulfate, and the rest is the same as Example 1.1.

[0045] Example 7.1 A method for preparing a microbial fungicide, which is different from Example 1.1 in that: in step III, the surfactant is 2.5g of sodium dodecylbenzene sulfonate and 2.5g of coconut oil fatty acid diethanolamide, and the rest is the same as Example 1.1.

[0046] Example 7.2 A method for preparing a microbial fungicide, which is different from that of Example 1.1 in that: in step III, the surfactant is 5 g of coconut oil fatty acid diethanolamide, and the rest is the same as that of Example 1.1.

[0047] Comparative Example 1.1 The difference from Example 1.1 is that in step I, Trichoderma harzianum in the microbial source is removed, and the weight ratio of Bacillus licheniformis, Trichoderma viride and Pythium oligandrum is still maintained at 50:15:10, and the rest is the same as Example 1.1.

[0048] Comparative Example 1.2 The difference from Example 1.1 is that in step I, the green Trichoderma in the microbial source is removed, and the weight ratio of Bacillus licheniformis, Trichoderma harzianum and Pythium oligandrum is still maintained at 50:20:10, and the rest is the same as Example 1.1.

[0049] Comparative Example 1.3 The difference from Example 1.1 is that in step I, the oligandrum in the microbial source is removed, and the weight ratio of Bacillus licheniformis, Trichoderma harzianum and Trichoderma viride is still maintained at 50:20:15, and the rest is the same as Example 1.1.

[0050] Comparative Example 2.1 The difference from Example 1.1 is that in step III, 30 g of sodium lactate and 30 g of calcium sulfate are all replaced by zeolite, and the rest is the same as Example 1.1.

[0051] Comparative Example 2.2 The difference from Example 1.1 is that in step III, sodium lactate is removed and the amount of calcium sulfate used is 60 g, and the rest is the same as Example 1.1.

[0052] Comparative Example 2.3 The difference from Example 1.1 is that in step III, calcium sulfate is removed and the amount of sodium lactate is 60 g, and the rest is the same as Example 1.1.

[0053] Performance Testing 1. Add a small amount of sterile distilled water to the rice sheath blight plate that has been cultured for 5 days, scrape the spores with a coating rod, and adjust the concentration to 107 cfu / mL with sterile distilled water after collection, which is the spore suspension. Take 2mL of the rice sheath blight spore suspension to the melted PDA medium (0.7% agar, 100mL, 45°C), shake well, and accurately take 10mL of the above culture medium to the solidified PDA plate (20mL per plate). After solidification, punch holes with a 5mm diameter puncher and pick out the bacterial cake. Take the microbial bactericide prepared in the embodiment and comparative example, dilute it 10 times with sterile distilled water, shake it evenly, draw 50uL and add it to the hole containing the rice sheath blight plate, culture it at a constant temperature of 25°C for 48h, measure the diameter of the inhibition zone, and record the results in Table 1; 2. According to the method for determining the suspension rate of pesticides in the national standard GB / T 14825-, the suspension rates of the active ingredients of the microbial fungicides obtained in the examples and comparative examples were determined and calculated, and the results were recorded in Table 1; 3. According to the records in GB / T 17980-110-2004, a greenhouse pot control experiment was carried out. First, seed dressing treatment was carried out: seed dressing with microbial fungicide, the dosage was 100kg of test seeds plus 500g of fungicide, and water dressing was used as a control. The test wheat was Yangmai 16, which was moderately susceptible to sheath blight. The treatment of seed dressing with pesticides was made by fresh mixing, and the seeds were mixed according to the ratio of drug dosage: test seed weight = 1:50, and naturally air-dried and sown. 20 wheat seeds treated with pesticides were sown in each plastic pot (diameter 18cm×height 20cm), and each treatment was arranged in random blocks, and repeated 4 times. In the experiment, the occurrence of wheat sheath blight was artificially inoculated, and the inoculation method was the furrow inoculation method. First, the infected wheat kernels were made, and the full and disease-free wheat kernels were selected. After soaking and imbibition, they were placed in double-layer plastic bags. After sterilization, the mycelium was inoculated and cultured for 15-20d (25℃). During this period, the wheat kernels were regularly turned over until the mycelium evenly covered the culture medium. When wheat is sown, the seeds and infected wheat grains are evenly applied to the soil, and the inoculation amount is about 5g / pot of infected wheat grains. During the heading period of wheat, a 7-level classification method is used for investigation: Level 0 means no disease; Level 1 means leaf sheath disease but no stem disease; Level 3 means leaf sheath disease and invasion of stem, but the stem lesions are less than 1 / 2 of the stem; Level 5 means stem lesions are more than 1 / 2 of the stem, but not lodging or breaking; Level 7 means dead, lodging, withered white ears. The calculation formula for the control effect is: Control effect % = (disease index of blank control area - disease index of treatment area) / disease index of blank control area × 100%, and the results are recorded in Table 1.

[0054] Table 1 Performance test table Data Analysis: As can be seen from Table 1, the microbial fungicide of Examples 1.1-1.2 has an inhibition zone diameter of 16.2-16.3 mm, an effective ingredient suspension rate of up to 97.85-97.89%, and a control effect of 71.5-71.8%, which proves that the microbial source of the present application has a highly efficient bactericidal effect, and the carrier has good adsorption and protection capabilities. In addition, the system is also doped with dispersants, surfactants and synergists. Various substances cooperate with each other to give full play to the synergistic effect, and finally a microbial fungicide with high bactericidal ability, high stability and long-acting bactericidal ability is obtained.

[0055] Examples 2.1-2.2 improve the culture conditions of the microbial source in step I. The data show that the diameter of the inhibition zone is significantly larger than that of Example 1.1, and the control effect is also better than that of Example 1.1, proving that the present application, by culturing within a specific temperature range, enables Bacillus to better form spores with strong stress resistance within this temperature range, thereby increasing its adaptability to the environment; Trichoderma harzianum and Trichoderma viride can more effectively produce antibacterial substances under suitable low temperature conditions, thereby enhancing the bactericidal efficacy; and Pythium oligandrum also exhibits higher parasitic ability and anti-pathogenic effect within this temperature range, thereby improving the bactericidal effect of the final microbial fungicide.

[0056] In Examples 3.1-3.6, the microbial fungicides of Examples 3.3-3.4 obviously have higher prevention and control effects and larger inhibition zone diameters, proving that the present application improves the overall bactericidal effect of the microbial fungicide by giving full play to the different bactericidal mechanisms and action ranges of the two strains of Bacillus amyloliquefaciens and Bacillus thuringiensis, while also reducing the dosage while ensuring efficient and stable antibacterial performance.

[0057] The dispersants in Examples 5.1-5.2 are different from those in Example 1.1. The results show that the suspension rate of the active ingredients is improved, and the control effect is also improved accordingly. This proves that the present application can significantly improve the uniform dispersion of the microbial fungicide by mixing sodium lignin sulfonate, quinoline copper and polycarboxylate dispersants in a specific proportion, ensuring that the components are fully mixed and avoiding the problem of poor bactericidal effect in some areas due to uneven dispersion.

[0058] The carriers of Examples 6.1-6.2 are different from those of Example 1.1. The results show that the suspension rate of the effective ingredients is improved, and the control effect is also improved accordingly. This proves that the present application fully utilizes the advantages of each component by using a specific proportion of sodium lactate, calcium sulfate and manganese sulfate as carriers, and can better exert synergistic effects, thereby improving the overall stability and long-term effectiveness of the microbial fungicide, and making it exhibit more excellent performance in practical applications.

[0059] The surfactants in Examples 7.1-7.2 are different from those in Example 1.1. The results show that the suspension rate of the active ingredients is improved, and the control effect is also improved accordingly, proving that the present application utilizes sodium dodecylbenzene sulfonate with strong hydrophilicity and detergency, which helps to improve the overall stability and uniformity of the solution; coconut oil fatty acid diethanolamide has good emulsification ability and skin friendliness, which can further improve the physical properties of the preparation, making it easier to apply and maintain its effective effect in the environment for a longer time, and can effectively promote the mixing of microbial source fermentation broth with other components, improve the adhesion and diffusion performance of the fungicide on the target surface, thereby enhancing its bactericidal effect.

[0060] The microbial sources of comparative examples 1.1-1.3 are different from those of example 1.1. The results show that the diameter of the inhibition zone is greatly reduced and the control effect is also reduced. This proves that the present application utilizes a combination of Bacillus, Trichoderma harzianum, Trichoderma viride and Pythium oligandrum. Compared with the bactericidal effect of using only one or two microbial sources, the bactericidal effect can be improved while reducing the dosage.

[0061] The carrier of comparative examples 2.1-2.2 is different from that of example 1.1. The results show that the suspension rate of the effective ingredients is greatly reduced, and the control effect is also reduced. This proves that the present application uses at least two of sodium lactate, calcium sulfate and manganese sulfate as carriers to give full play to the good water solubility and biocompatibility of sodium lactate. In addition, the porous structure of calcium sulfate adsorbs the main bactericidal active substances in the microbial fungicide. Manganese sulfate has both good water solubility and excellent active metal ion providing ability. The compounding of at least two of the three can greatly improve the stability and long-term effect of the microbial fungicide.

[0062] The embodiments of this specific implementation method are all preferred embodiments of the present application, and are not intended to limit the protection scope of the present application. Therefore, all equivalent changes made based on the structure, shape, and principle of the present application should be included in the protection scope of the present application.

Claims

1. A microbial bactericide, characterized in that: The raw materials used include the following components by weight: 40-45 parts of microbial fermentation liquid; 50-60 parts of carrier; 2-3 parts of dispersant; 3-5 parts of surfactant; 0.5-1 part of synergist; the microbial source in the microbial fermentation liquid includes Bacillus, Trichoderma harzianum, Trichoderma viride and Pythium oligandrum in a weight ratio of 50: (20-25): (10-15): 10, and the carrier includes at least two of sodium lactate, calcium sulfate and manganese sulfate.

2. A microbial bactericide according to claim 1, characterized in that: The Bacillus includes Bacillus amyloliquefaciens and Bacillus thuringiensis.

3. A microbial bactericide according to claim 2, characterized in that: The weight ratio of the Bacillus amyloliquefaciens to the Bacillus thuringiensis is 5:(2-3).

4. A microbial bactericide according to claim 1, characterized in that: The auxiliary dispersant includes one or more of sodium lignin sulfonate, phenethylphenol polyoxyethylene ether, quinoline copper and polycarboxylate type dispersants.

5. A microbial bactericide according to claim 4, characterized in that: The auxiliary dispersant comprises sodium lignin sulfonate, quinoline copper and a polycarboxylate dispersant in a weight ratio of 3:(1-1.5):(1.5-1.8).

6. A microbial bactericide according to claim 1, characterized in that: The carrier includes sodium lactate, calcium sulfate and manganese sulfate in a weight ratio of 20:(8-10):

5.

7. A microbial bactericide according to claim 1, characterized in that: The surfactant includes sodium dodecylbenzene sulfonate and coconut oil fatty acid diethanolamide.

8. A method for preparing the microbial bactericide according to any one of claims 1 to 7, characterized in that: The following steps are involved: I. Activation and cultivation of microbial sources: Activate the microbial source, then inoculate and cultivate it at an inoculation rate of 8-10% to obtain a microbial source fermentation liquid; II. preparing fermentation broth from microorganisms; III. Preparation of microbial fungicide: The microbial source fermentation liquid obtained in step II is mixed with a carrier, stirred until the system is uniform and then dried, then mixed with a dispersant, a surfactant and a synergist, and crushed to obtain a microbial fungicide.

9. The method for preparing a microbial bactericide according to claim 8, characterized in that: In the step I, the culture temperature of Bacillus is 28-32°C, and the culture temperature of Trichoderma harzianum, Trichoderma viride and Pythium oligandrum is 25-28°C.

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