Method for preparing bio-fertilizer by using isoleucine fermentation liquor

Abstract

The invention relates to the technical field of biological fertilizers, in particular to a method for preparing a biological fertilizer by using isoleucine fermentation broth, which comprises the following steps: adding an additive prepared in advance into a biological liquid initial fertilizer prepared from isoleucine, and stirring for 1-3 hours under the conditions that the temperature is 37 DEG C and the rotating speed is 200-600 revolutions per minute to obtain a biological liquid fertilizer; the beta-cyclodextrin microsphere monomer has a special complex cavity structure and is modified with starch by adopting a chemical bond combination method to form a brand-new functional polymer, so that the chelation of the beta-cyclodextrin monomer is reserved, and the beta-cyclodextrin microsphere monomer has higher adsorption capacity; the nutritional agent can be continuously dispersed, so that the fertilizing time of the bio-fertilizer can be greatly prolonged.

Description

Technical Field

[0001] The invention relates to the technical field of biofertilizers, and in particular to a method for preparing biofertilizers by utilizing isoleucine fermentation liquid. Background Art

[0002] Chinese patent CN110903136A discloses a microbial fertilizer and a preparation method thereof, belonging to the technical field of fertilizers. The present invention introduces a composite bacterial agent (Lactobacillus oris and Pseudomonas aeruginosa) into the traditional basic fertilizer, which can not only effectively enhance the anti-infection ability of tomatoes to tomato early blight, but also can be fermented by urea, amino acid solution, potassium dihydrogen phosphate, D-tryptophan, magnesium nitrate, etc. in the microbial fertilizer; the combination of bacterial agents, yeast powder and other raw materials in the microbial fertilizer can be stably present in the microbial fertilizer and maintain activity through a suitable preparation method. Experiments show that the microbial fertilizer can effectively promote the growth of tomatoes and prevent and control the infection of tomato early blight; In the prior art, how to improve the stress resistance of crops, promote the growth and development of crops, and improve the quality of fruits by using isoleucine in fertilizers; how to make the nutrient agent be continuously emitted will greatly increase the fertilizer time of biological fertilizers. Summary of the invention

[0003] The purpose of the present invention is to provide a method for preparing a biological fertilizer by using isoleucine fermentation liquid. The technical problems solved by the present invention are: how to improve the stress resistance of crops, promote the growth and development of crops, and improve the quality of fruits by using isoleucine in fertilizers; how to make the nutrient agent be continuously emitted, which will greatly increase the fertilizer time of the biological fertilizer.

[0004] The purpose of the present invention can be achieved through the following technical solutions: A method for preparing biofertilizer using isoleucine fermentation liquid comprises the following steps: Add the pre-prepared additive to the initial biological liquid fertilizer prepared from isoleucine, stir for 1-3 hours at a temperature of 37° C. and a rotation speed of 200-600 rpm to obtain a biological liquid fertilizer; The preparation process of the additive is: Step 31: β-cyclodextrin and pretreated starch are mixed in a mass ratio of 2-4:1, and then deionized water of 6-10 times the mass of the pretreated starch is added, the pH value is adjusted to 10-11, and then a cross-linking agent is added to perform pulse electric field treatment under the conditions of 20-40 KV / cm and 200-300 Hz, and then centrifuged, washed with water and dried in sequence to obtain starch-β-cyclodextrin; Step 32: After starch-β-cyclodextrin and the emulsifier are mixed, magnetic stirring is performed at 50-60°C and 500-600r / min for 0.5-0.8h, and then 10-20 times by weight of the nutrient, 0.2-0.4 times by weight of the cross-linking agent and 0.1-0.3 times by weight of the initiator are added and stirring is continued for 10-20h, and then anhydrous ethanol is added to break the emulsion, and finally centrifuged, washed and dried in sequence to obtain the additive.

[0005] As a further solution of the present invention: the preparation process of the nutrient agent comprises: mixing urea, potassium sulfate, diammonium phosphate, amino acid liquid, Bacillus subtilis, Bacillus licheniformis and Bacillus megaterium according to the following weight ratio.

[0006] As a further solution of the present invention: the nutrient agent includes urea: potassium sulfate: diammonium phosphate: amino acid liquid: Bacillus subtilis: Bacillus licheniformis: Bacillus megaterium in a weight ratio of 50-150: 50-150: 100-200: 600-750.

[0007] As a further solution of the present invention: the cross-linking agent is epichlorohydrin.

[0008] As a further embodiment of the present invention: the initiator is potassium persulfate and / or sodium bisulfite.

[0009] As a further embodiment of the present invention, the steps of preparing the biological liquid initial fertilizer from isoleucine are: 0.3%-1% protease is added to the isoleucine fermentation mixed solution to hydrolyze bacterial protein, and the temperature of the mixed solution is controlled to rise to 60°C and then maintained for 20 minutes to inactivate enzyme activity, thereby obtaining a biological liquid initial fertilizer.

[0010] As a further scheme of the present invention: the preparation process of the isoleucine fermentation mixed liquid is as follows: the isoleucine-producing Escherichia coli seed liquid is inoculated into the corn steep liquor obtained at an inoculation rate of 20-30% for culturing for 4 to 6 hours, and then the culture temperature is increased to 90°C and maintained for 15 minutes to inactivate the bacteria, thereby obtaining the isoleucine fermentation mixed liquid.

[0011] As a further solution of the present invention: the culture conditions are: temperature 37°C, dissolved oxygen ≥30%, 200-600 rpm, and pressure 0.05 MPa.

[0012] As a further solution of the present invention: during the culture process, the pH value in the fermentation tank is maintained in the range of [7.0, 7.2] by automatic control of ammonia water.

[0013] As a further solution of the present invention: the reaction conditions of the protease are pH 7.0, temperature 37°C, and hydrolysis time 4h.

[0014] Beneficial effects of the present invention: The present invention prepares biological fertilizer by isoleucine fermentation liquid, and the effect of isoleucine in fertilizer is mainly reflected in the following aspects: Improve stress resistance: As a kind of amino acid, isoleucine can improve the ability of crops to resist salt stress, which helps crops grow normally under adverse conditions such as saline-alkali land; at the same time, it can also improve pollen vitality and germination rate, which is beneficial to crop reproduction and growth; Promote growth: Isoleucine can work with other amino acids such as leucine and valine to promote the growth and development of crops; these amino acids can be converted into energy substances such as glucose in the crop body, providing the necessary energy support for the growth of crops; Improve fruit quality: Isoleucine can also improve the flavor of crop fruits, making them more delicious; this helps to increase the commodity value and market competitiveness of crops; In addition, as one of the basic units of protein, isoleucine is easily absorbed. Adding isoleucine to fertilizers can allow crops to absorb more amino acids through exogenous application, thereby giving full play to the function of amino acids in plant physiological regulation and improving crop yield and quality. In general, the application of isoleucine in fertilizers can not only improve the stress resistance of crops, promote the growth and development of crops, but also improve the quality of fruits; Furthermore, the present invention uses the β-cyclodextrin microsphere monomer with a special complex cavity structure, and modifies it with starch by chemical bonding to form a new functional polymer, which not only retains the inclusion effect of the β-cyclodextrin monomer, but also has a strong adsorption capacity; so that the nutrient can be continuously emitted, which will greatly increase the fertilizer time of the biological fertilizer; Among them, urea: provides nitrogen nutrition. Urea is a nitrogen fertilizer with a high nitrogen content, which can provide plants with the required nitrogen nutrition. Nitrogen is one of the important nutrients for plant growth and plays an important role in promoting plant growth, improving yield and quality. The nitrogen element in urea is easily absorbed and utilized by plants, which can quickly supplement the lack of nitrogen in the soil and meet the plant's demand for nitrogen. Promote plant growth. The nitrogen element provided by urea can stimulate the growth of plant stems and leaves, increase the growth rate and quantity, and thus promote the overall growth and development of crops. In addition, urea can also promote the development of plant roots, increase the number and length of roots, enhance absorption capacity, and improve plant resistance, such as drought resistance, cold resistance, disease and pest resistance, etc. Improve soil structure. When urea decomposes in the soil, it releases some beneficial compounds, such as B vitamins, which can promote the reproduction and activity of microorganisms in the soil. When microorganisms decompose organic matter, they release some adhesive substances, which help to form soil aggregate structure, thereby improving the soil's ability to retain water and fertilizer. In addition, urea can also absorb harmful substances in the soil and reduce its pollution to the environment. Regulating soil pH. Urea quickly decomposes into ammonium ions in the soil, and releases hydrogen ions during the ammoniation process, making the soil slightly acidic. This is very beneficial for acidic soils and soils with unbalanced pH values. It helps to regulate the chemical properties of the soil, improve soil fertility, and promote the absorption of nutrients by plant roots. Improving crop quality. As an important raw material for protein synthesis, nitrogen has a direct impact on crop quality. Appropriate use of urea fertilizer can increase the protein content in crops, improve the nutritional value and taste of food, and help improve the quality of food processing. In addition, urea can promote the accumulation of sugar in fruits, bright color, and improve the taste and flavor of fruits. Potassium sulfate: Provides potassium nutrition. Potassium sulfate is a highly efficient potassium fertilizer, containing 46%-52% potassium, which can provide plants with rich potassium nutrition. Potassium is one of the macroelements necessary for plant growth and plays an important role in promoting plant photosynthesis, respiration, material transport and other physiological processes.

[0015] Promote crop growth and development; Enhance stress resistance: Potassium ions in potassium sulfate can stimulate plants to produce more osmotic regulating substances, help plants better resist environmental pressures such as drought and salinity, reduce the damage to crops caused by adverse environments, and thus ensure the normal growth and development of crops; Promote root development: Potassium can promote the growth and development of plant roots, making the root system more developed, which is beneficial to the absorption and utilization of water and nutrients by plants; Improve photosynthesis efficiency: Potassium can improve the photosynthesis efficiency of plants, promote the synthesis and transportation of carbohydrates, and is beneficial to the growth and development of plants. Improve soil structure: After potassium sulfate is applied to the soil, it can form stable aggregates, improve the physical properties of the soil, and improve the air permeability and water permeability of the soil. This is conducive to the activity of microorganisms and the decomposition of organic matter, and promotes the transformation and release of nutrients. At the same time, a good soil structure also helps to maintain the balance of water and nutrients, prevent soil erosion, and is beneficial to the extension of the root system and the absorption of nutrients. Improve crop quality and yield; Increase yield: The application of potassium sulfate can significantly increase crop yield, especially in potassium-deficient areas or on potassium-deficient crops; Improve quality: Potassium plays an important role in improving crop quality. It can improve the taste and flavor of crops, increase the sugar content and solid content of fruits, and make the fruits more delicious. At the same time, potassium can also promote protein synthesis and accumulation of crops, and improve the nutritional value of crops; Diammonium phosphate: Providing key nutrients, Diammonium phosphate is a highly efficient nitrogen-phosphorus compound fertilizer containing 17%-21% nitrogen (N) and 46%-53% phosphorus (P2O5). These elements are indispensable for plant growth and are of great significance for promoting plant growth and development. Nitrogen helps the growth of plant leaves and stems, increases chlorophyll content, and enhances photosynthesis; phosphorus mainly promotes the development of plant roots, improves the ability of crops to resist pests and diseases, and forms flowers and fruits. Promoting root development and enhancing stress resistance, the phosphorus element in diammonium phosphate is particularly important for the formation and development of crop roots. It can effectively promote the early development of crop roots, enhance the ability of roots to absorb water and nutrients, and lay a solid foundation for the entire growth cycle of crops. Especially for gramineous crops such as corn, an adequate supply of phosphorus can significantly improve the development of their root systems, thereby enhancing the ability of crops to resist lodging and water use efficiency. In addition, phosphorus can also enhance the resistance of crops to adversities such as drought and cold, and reduce the risk of yield reduction due to environmental factors. Improve fertilizer utilization and simplify fertilization operations. Diammonium phosphate is a fast and effective fertilizer that can be quickly absorbed and utilized by plants. Its nutrient release is relatively uniform, and the fertilizer effect is long-lasting, which can meet the nutrient needs of crops throughout the entire growth cycle. The use of diammonium phosphate can reduce the number of fertilizations and the amount of labor, especially for farmers who grow crops on a large scale, which can significantly reduce production costs. In addition, diammonium phosphate particles are solid, dust-free, and uniform in size, which are easy to store and use, and also convenient for mechanized fertilization. Improve soil and regulate plant growth. The phosphate ions in diammonium phosphate can combine with iron, aluminum and other ions in the soil to form insoluble precipitation, thereby reducing the acidity of the soil and improving the soil structure. At the same time, diammonium phosphate can also adjust the pH value of the soil, making it more suitable for plant growth and development. In acidic soils, diammonium phosphate can neutralize the acidity of the soil and improve the fertility of the soil; in alkaline soils, although diammonium phosphate is easily leached, appropriate application still helps to improve the soil environment. Amino acid solution: Provide nutritional support. Amino acid solution is an organic nitrogen source that can be directly absorbed and utilized by plants. It is rich in amino acids and trace elements. These ingredients can provide comprehensive nutritional support for plants and promote plant growth and development. Especially when plants are in the vegetative growth stage, the application of amino acid solution can significantly increase the growth rate and biomass of plants. Promote root development. Amino acid solution has a significant promoting effect on plant root development. It can stimulate the growth of plant roots, increase the number and length of roots, and improve the root system's ability to absorb water and nutrients. This is of great significance for improving plant stress resistance and yield. At the same time, some ingredients in amino acid solution can also promote the production of secretions from plant roots, which is beneficial to the reproduction and activity of microorganisms in the soil and further improves the soil environment. Improve photosynthesis efficiency. Some amino acids in amino acid solution can increase the content of plant chlorophyll, promote the absorption and utilization of carbon dioxide by plants, and increase the power of photosynthesis. This can not only improve the photosynthesis efficiency of plants, but also increase the accumulation of organic matter in plants, and improve the yield and quality of crops. Enhance stress resistance. The various amino acids and trace elements in amino acid solution can enhance the stress resistance of plants. For example, some amino acids can improve the ability of plants to resist drought, cold, and disease, so that plants can maintain a good growth state under adverse conditions. This is of great significance for improving the adaptability and yield stability of crops. Improve the soil environment. The organic matter in the amino acid solution can combine with the inorganic matter in the soil to form a stable organic-inorganic complex and improve the soil structure. At the same time, the amino acid solution can also promote the reproduction and activity of microorganisms in the soil, improve the fertility and air permeability of the soil. This plays an important role in improving the root development and nutrient absorption capacity of crops. Improve fertilizer utilization rate. The amino acid solution has a high base exchange capacity, which can reduce the volatilization loss of nitrogen, promote the acceleration of organic nitrogen mineralization, and increase the content of available nitrogen in the soil. In addition, the amino acid solution can also undergo a chelation reaction with the insoluble trace elements in the soil, promote the transfer of trace elements from the roots to the aboveground parts, and improve the absorption and utilization rate of trace elements by plants. Bacillus subtilis: Provides nutrition and promotes growth. Bacillus subtilis can produce substances similar to cytokinins and plant growth hormones. These substances can increase the level of crop growth hormones, thereby promoting the growth and reproduction of crops. At the same time, it can also induce plant resistance and help plants resist the invasion of pathogens. Bacillus subtilis can produce a variety of substances with antibacterial and bacteriolytic effects during its growth, such as subtilisin, organic acids, antibacterial proteins, etc. These substances can inhibit the growth and reproduction of pathogens, and even destroy the bacterial structure and kill pathogens. Therefore, after Bacillus subtilis is applied in the soil, it can compete with other microorganisms for oxygen and nutrients, form a dominant biological population, effectively prevent the invasion of other pathogens, and play a role in disease prevention and disease resistance. This has a significant effect on the prevention and control of diseases such as continuous cropping disease, root rot, and gray mold. Improve soil and fertilize soil fertility. Bacillus subtilis can decompose soil organic matter and convert it into humus that can be directly absorbed and utilized by crops. At the same time, it can also improve the soil's granular structure, break up compaction, increase looseness, effectively curb soil degradation, and improve saline-alkali land. In addition, Bacillus subtilis can also improve the microbial structure in the soil, reduce the production of pathogens, and improve the ecological environment. Improve fertilizer utilization and reduce costs. Bacillus subtilis can produce a variety of enzyme substances, which can decompose insoluble nutrients in the soil and improve their utilization rate. At the same time, due to the antibacterial and bactericidal effects of Bacillus subtilis, it can reduce the occurrence of crop diseases, thereby reducing the use of pesticides. In addition, Bacillus subtilis fertilizer has a good fertilizer effect, which can reduce the use of chemical fertilizers and reduce production costs; Bacillus licheniformis produces auxin-like substances: Bacillus licheniformis can produce a variety of auxin-like substances, such as indoleacetic acid, which can promote the growth and development of the root system, increase the water and oxygen absorption capacity of plants, and promote the growth and development of plants; improve fertilizer utilization: Bacillus licheniformis can increase the utilization rate of fertilizers by plants, promote the formation and accumulation of nitrogen in plants, reduce nutrient loss, and improve fertilizer effects; promote photosynthesis: Bacillus licheniformis can indirectly improve the photosynthesis efficiency of plants and increase the accumulation of organic matter in plants by improving the soil environment and promoting plant growth; Bacillus megaterium is rich in plant nutrients such as nitrogen, phosphorus, and potassium, which are essential basic substances for plant growth. At the same time, it can also produce plant growth-promoting substances such as growth hormones and organic acids, which have a positive impact on the growth and development of crops. By decomposing organic matter in the soil, Bacillus megaterium can release the nutrients required for plant growth, such as phosphorus and potassium, for plants to absorb and utilize. DETAILED DESCRIPTION

[0016] The following will be combined with the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0017] Example 1 The present invention provides a method for preparing biofertilizer by utilizing isoleucine fermentation liquid, comprising the following steps: Step 1: Inoculate the isoleucine-producing Escherichia coli seed liquid with an inoculation rate of 20% into the corn steep liquor obtained for cultivation, and the culture conditions are: temperature 37°C, dissolved oxygen ≥30%, 200-600 rpm, pressure 0.05Mpa, and maintain the pH value in the fermentation tank in the range of [7.0, 7.2] by automatic control of ammonia water during the culture process, and culture for 4 to 6 hours, then increase the culture temperature to 90°C and maintain it for 15 minutes to inactivate the bacteria, and obtain an isoleucine fermentation mixed liquid; Step 2: adding 0.3% protease to the isoleucine fermentation mixed solution to hydrolyze bacterial protein, wherein the reaction conditions of the protease are pH 7.0, temperature 37°C, and after the hydrolysis time is 4 hours, the temperature of the mixed solution is controlled to rise to 60°C and maintained for 20 minutes to inactivate the enzyme activity, thereby obtaining the initial biological liquid fertilizer; Step 3: adding the pre-prepared additive to the initial biological liquid fertilizer, stirring for 1-3 hours at a temperature of 37° C. and a rotation speed of 200-600 rpm to obtain a biological liquid fertilizer; The preparation process of the additive is as follows: Step 31: β-cyclodextrin and pretreated starch are mixed in a mass ratio of 2:1, and then deionized water of 6 times the mass of the pretreated starch is added, the pH value is adjusted to 10-11, and then a cross-linking agent is added to perform pulse electric field treatment under the conditions of 20-40 KV / cm and 200-300 Hz, and then centrifuged, washed with water and dried in sequence to obtain starch-β-cyclodextrin; Step 32: After starch-β-cyclodextrin and the emulsifier are mixed, magnetic stirring is performed at 50-60°C and 500-600r / min for 0.5-0.8h, and then 10-20 times by weight of the nutrient, 0.2 times by weight of the cross-linking agent and 0.1 times by weight of the initiator are added and stirring is continued for 10-20h, and then anhydrous ethanol is added for demulsification, and finally centrifugation, washing and drying are performed in sequence to obtain the additive; The preparation process of the nutrient agent comprises: mixing urea, potassium sulfate, diammonium phosphate, amino acid solution, Bacillus subtilis, Bacillus licheniformis and Bacillus megaterium according to the following weight ratio, and stirring for 1-3 hours at a rotation speed of 200-600 rpm; The nutrient agent includes urea: potassium sulfate: diammonium phosphate: amino acid liquid: Bacillus subtilis: Bacillus licheniformis: Bacillus megaterium in a weight ratio of 50:50:100:600:3:3:4; The cross-linking agent is epichlorohydrin, and the initiator is potassium persulfate and / or sodium bisulfite.

[0018] Example 2 The present invention provides a method for preparing biofertilizer by utilizing isoleucine fermentation liquid, comprising the following steps: Step 1: Inoculate the isoleucine-producing Escherichia coli seed liquid with an inoculation rate of 25% into the corn steep liquor obtained for culturing, and the culture conditions are: temperature 37°C, dissolved oxygen ≥30%, 200-600 rpm, pressure 0.05Mpa, and maintain the pH value in the fermentation tank in the range of [7.0, 7.2] by automatic control of ammonia water during the culturing process, and culture for 4 to 6 hours, then increase the culture temperature to 90°C and maintain it for 15 minutes to inactivate the bacteria, and obtain an isoleucine fermentation mixed liquid; Step 2: adding 0.8% protease to the isoleucine fermentation mixed solution to hydrolyze bacterial protein, wherein the reaction conditions of the protease are pH 7.0, temperature 37°C, and after the hydrolysis time is 4 hours, the temperature of the mixed solution is controlled to rise to 60°C and maintained for 20 minutes to inactivate the enzyme activity, thereby obtaining the initial biological liquid fertilizer; Step 3: adding the pre-prepared additive to the initial biological liquid fertilizer, stirring for 1-3 hours at a temperature of 37° C. and a rotation speed of 200-600 rpm to obtain a biological liquid fertilizer; The preparation process of the additive is as follows: Step 31: β-cyclodextrin and pretreated starch are mixed in a mass ratio of 3:1, and then 8 times the mass of deionized water of the pretreated starch is added, the pH value is adjusted to 10-11, and then a cross-linking agent is added to perform pulse electric field treatment under the conditions of 20-40 KV / cm and 200-300 Hz, and then centrifuged, washed with water and dried in sequence to obtain starch-β-cyclodextrin; Step 32: After starch-β-cyclodextrin and the emulsifier are mixed, magnetic stirring is performed at 50-60°C and 500-600r / min for 0.5-0.8h, and then 15 times by weight of the nutrient, 0.3 times by weight of the cross-linking agent and 0.2 times by weight of the initiator are added and stirring is continued for 10-20h, and then anhydrous ethanol is added for demulsification, and finally centrifugation, washing and drying are performed in sequence to obtain the additive; The preparation process of the nutrient agent comprises: mixing urea, potassium sulfate, diammonium phosphate, amino acid solution, Bacillus subtilis, Bacillus licheniformis and Bacillus megaterium according to the following weight ratio, and stirring for 1-3 hours at a rotation speed of 200-600 rpm; The nutrient agent includes urea: potassium sulfate: diammonium phosphate: amino acid liquid: Bacillus subtilis: Bacillus licheniformis: Bacillus megaterium in a weight ratio of 100:100:150:700:3:3.5:4.5; The cross-linking agent is epichlorohydrin, and the initiator is potassium persulfate and / or sodium bisulfite.

[0019] Example 3 The present invention provides a method for preparing biofertilizer by utilizing isoleucine fermentation liquid, comprising the following steps: Step 1: Inoculate the isoleucine-producing Escherichia coli seed liquid with an inoculation rate of 30% into the corn steep liquor obtained for culturing, and the culturing conditions are: temperature 37°C, dissolved oxygen ≥30%, 200-600 rpm, pressure 0.05Mpa, and maintain the pH value in the fermentation tank in the range of [7.0, 7.2] by automatic control of ammonia water during the culturing process, and cultivate for 4 to 6 hours, then increase the culture temperature to 90°C and maintain for 15 minutes to inactivate the bacteria, and obtain an isoleucine fermentation mixed liquid; Step 2: adding 1% protease to the isoleucine fermentation mixed solution to hydrolyze bacterial protein, wherein the reaction conditions of the protease are pH 7.0, temperature 37°C, and after the hydrolysis time is 4 hours, the temperature of the mixed solution is controlled to rise to 60°C and maintained for 20 minutes to inactivate the enzyme activity, thereby obtaining the biological liquid initial fertilizer; Step 3: adding the pre-prepared additive to the initial biological liquid fertilizer, stirring for 1-3 hours at a temperature of 37° C. and a rotation speed of 200-600 rpm to obtain a biological liquid fertilizer; The preparation process of the additive is as follows: Step 31: β-cyclodextrin and pretreated starch are mixed in a mass ratio of 4:1, and then deionized water 10 times the mass of the pretreated starch is added, the pH value is adjusted to 10-11, and then a cross-linking agent is added to perform pulse electric field treatment under the conditions of 20-40 KV / cm and 200-300 Hz, and then centrifuged, washed with water and dried in sequence to obtain starch-β-cyclodextrin; Step 32: After starch-β-cyclodextrin and the emulsifier are mixed, magnetic stirring is performed at 50-60°C and 500-600r / min for 0.5-0.8h, and then 20 times by weight of the nutrient, 0.4 times by weight of the cross-linking agent and 0.3 times by weight of the initiator are added and stirring is continued for 10-20h, and then anhydrous ethanol is added for demulsification, and finally centrifugation, washing and drying are performed in sequence to obtain the additive; The preparation process of the nutrient agent comprises: mixing urea, potassium sulfate, diammonium phosphate, amino acid solution, Bacillus subtilis, Bacillus licheniformis and Bacillus megaterium according to the following weight ratio, and stirring for 1-3 hours at a rotation speed of 200-600 rpm; The nutrient agent includes urea: potassium sulfate: diammonium phosphate: amino acid liquid: Bacillus subtilis: Bacillus licheniformis: Bacillus megaterium in a weight ratio of 150:150:200:750:3:4:5; The cross-linking agent is epichlorohydrin, and the initiator is potassium persulfate and / or sodium bisulfite.

[0020] The above is a detailed description of an embodiment of the present invention, but the content is only a preferred embodiment of the present invention and cannot be considered to limit the scope of implementation of the present invention. All equivalent changes and improvements made within the scope of the present invention should still fall within the scope of the patent coverage of the present invention.

Claims

1. A method for preparing biofertilizer using isoleucine fermentation broth, characterized in that: The following steps are involved: Add the pre-prepared additive to the initial biological liquid fertilizer prepared from isoleucine, stir for 1-3 hours at a temperature of 37° C. and a rotation speed of 200-600 rpm to obtain a biological liquid fertilizer; The preparation process of the additive is: Step 31: β-cyclodextrin and pretreated starch are mixed in a mass ratio of 2-4:1, and then deionized water of 6-10 times the mass of the pretreated starch is added, the pH value is adjusted to 10-11, and then a cross-linking agent is added to perform pulse electric field treatment under the conditions of 20-40 KV / cm and 200-300 Hz, and then centrifuged, washed with water and dried in sequence to obtain starch-β-cyclodextrin; Step 32: After starch-β-cyclodextrin and the emulsifier are mixed, magnetic stirring is performed at 50-60°C and 500-600r / min for 0.5-0.8h, and then 10-20 times by weight of the nutrient, 0.2-0.4 times by weight of the cross-linking agent and 0.1-0.3 times by weight of the initiator are added and stirring is continued for 10-20h, and then anhydrous ethanol is added to break the emulsion, and finally centrifuged, washed and dried in sequence to obtain the additive.

2. The method for preparing biofertilizer using isoleucine fermentation broth according to claim 1, characterized in that: The preparation process of the nutrient agent comprises: mixing urea, potassium sulfate, diammonium phosphate, amino acid liquid, Bacillus subtilis, Bacillus licheniformis and Bacillus megaterium according to the following weight ratio.

3. The method for preparing biofertilizer using isoleucine fermentation broth according to claim 1, characterized in that: The nutrient agent includes urea: potassium sulfate: diammonium phosphate: amino acid liquid: Bacillus subtilis: Bacillus licheniformis: Bacillus megaterium in a weight ratio of 50-150: 50-150: 100-200: 600-750.

4. The method for preparing biofertilizer using isoleucine fermentation broth according to claim 1, characterized in that: The crosslinking agent is epichlorohydrin.

5. The method for preparing biofertilizer using isoleucine fermentation broth according to claim 1, characterized in that: The initiator is potassium persulfate and / or sodium bisulfite.

6. The method for preparing biofertilizer using isoleucine fermentation broth according to claim 1, characterized in that: The steps of preparing the biological liquid initial fertilizer from isoleucine are: 0.3%-1% protease is added to the isoleucine fermentation mixed solution to hydrolyze bacterial protein, and the temperature of the mixed solution is controlled to rise to 60°C and then maintained for 20 minutes to inactivate enzyme activity, thereby obtaining a biological liquid initial fertilizer.

7. A method for preparing biofertilizer using isoleucine fermentation broth according to claim 6, characterized in that: The preparation process of the isoleucine fermentation mixed liquid is as follows: the isoleucine-producing Escherichia coli seed liquid is inoculated into the corn steep liquor obtained at an inoculation rate of 20-30% for culturing for 4 to 6 hours, and then the culture temperature is increased to 90° C. and maintained for 15 minutes to inactivate the bacteria, thereby obtaining the isoleucine fermentation mixed liquid.

8. The method for preparing biofertilizer using isoleucine fermentation broth according to claim 7, characterized in that: The culture conditions were: temperature 37°C, dissolved oxygen ≥ 30%, 200-600 rpm, and pressure 0.05 MPa.

9. The method for preparing biofertilizer using isoleucine fermentation broth according to claim 8, characterized in that: During the cultivation process, the pH value in the fermentation tank is maintained in the range of [7.0, 7.2] through automatic control of ammonia water.

10. The method for preparing biofertilizer using isoleucine fermentation broth according to claim 9, characterized in that: The reaction conditions of the protease were pH 7.0, temperature 37°C, and hydrolysis time 4 h.