Method for preparing liquid fertilizer from isoleucine fermentation liquor

Abstract

The invention relates to the technical field of fertilizer preparation, and particularly discloses a method for preparing a liquid fertilizer from an isoleucine fermentation broth, which comprises the following steps: collecting the fermentation broth in an isoleucine fermentation tank, and filtering; carrying out low-temperature vacuum evaporation and concentration on the filtered fermentation liquor, and adding an enzyme preparation to carry out enzymolysis on long-chain protein in the fermentation liquor; adjusting the pH value of the fermentation liquor to 6-8; adding a potassium compound, a phosphide, a chelate and a reinforcing agent into the fermentation liquid; the moisture content in the fermentation liquid is reduced through filtration, and then the semi-solid fertilizer product is dried to obtain a powdery or granular fertilizer; the dried fertilizer is prepared into particles through a pelletizer; in the granulation process, the modified granulation agent is sprayed on the surfaces of formed fertilizer particles, better storage and transportation are facilitated, and meanwhile, in the use process of the fertilizer, nutrient supply is more sufficient, the action time is longer, the absorptivity of plants is more sufficient, and the plants grow faster and better.

Description

Technical Field

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

[0002] Isoleucine fermentation broth is a byproduct of the amino acid fermentation industry, which contains rich amino acids and other organic substances. The traditional treatment method is often to directly discharge these fermentation broths or perform simple treatments, but this not only wastes resources, but also may cause environmental pollution. Therefore, converting isoleucine fermentation broth into fertilizer is an environmentally friendly and economical way of utilization, which can effectively utilize the byproducts produced in the biological fermentation process, reduce waste emissions, and convert them into useful agricultural fertilizers.

[0003] In the existing fertilizer preparation process, the fertilizer prepared from isoleucine fermentation liquid has poor moisture resistance during transportation, a short storage time, and is prone to moisture. At the same time, when acting on crops, the effect is short and the effect is not obvious. Summary of the invention

[0004] The object of the present invention is to provide a method for preparing liquid fertilizer from isoleucine fermentation broth to solve the above-mentioned background problems.

[0005] The purpose of the present invention can be achieved through the following technical solutions: A method for preparing liquid fertilizer from isoleucine fermentation broth comprises the following steps: Step 1: Filtration and impurity removal: collect the fermentation broth in the isoleucine fermentation tank and filter it through a 50 μm sieve; Step 2: Evaporation and concentration: The filtered fermentation liquid is concentrated by low-temperature vacuum evaporation to concentrate the volume of the fermentation liquid to 30%-40% of the original solution volume; Step 3: Nitrogen source optimization: adding enzyme preparations to hydrolyze long-chain proteins in the fermentation broth; Then, the pH value of the fermentation liquid is adjusted to 6-8 by adding acid or alkali; Step 4: Efficacy adjustment: adding potassium compounds, phosphides, chelates and enhancers to the fermentation broth; Step 5: Dehydration and drying: reduce the water content in the fermentation liquid by filtering to form a semi-solid fertilizer product; then dry the semi-solid fertilizer product to obtain powder or granular fertilizer; Step 6: Antioxidant granulation: The dried fertilizer is prepared into granules with a diameter of 2-5 mm by a granulator; during the granulation process, the modified granulating agent is sprayed on the surface of the formed fertilizer granules for uniform coverage.

[0006] As a further solution of the present invention: in the step three, the amount of enzyme preparation added is 0.02%-0.05% of the total mass of the fermentation liquid, the enzymolysis temperature is 35°C-45°C, and the enzymolysis time is 4-6 hours.

[0007] As a further solution of the present invention: in the step 4, the mass ratio of the fermentation liquid, potassium compound, phosphide, chelate and enhancer is: 1000: 1-2: 0.5-1: 1-5: 1-3.

[0008] As a further solution of the present invention: in the step 4, the potassium compound is one or both of potassium sulfate and potassium chloride, and the phosphide is potassium dihydrogen phosphate.

[0009] As a further solution of the present invention: in the step 4, the chelate is a mixture of chelated iron, chelated zinc and chelated copper, and the mass ratio of chelated iron, chelated zinc and chelated copper is 5:3:2.

[0010] As a further embodiment of the present invention: the enhancer is one or both of humic acid and fulvic acid.

[0011] As a further solution of the present invention: the amount of the modified granulating agent added in step 6 is 2%-4% of the mass of the fertilizer after drying.

[0012] As a further scheme of the present invention: the preparation method of the modified granulating agent is: mixing the granulating agent, organic antioxidant, glycerol, nano-silicon dioxide, starch, mycorrhizal fungus preparation and distilled water according to 10-20: 5-10: 25-35: 5-8: 8-12: 1-3: 1000, stirring at a speed of 800-1000 r / min, heating to 60° C.-70° C., and obtaining a modified granulating agent solution.

[0013] As a further embodiment of the present invention: the granulating agent is one of polyvinyl alcohol, polyethylene glycol, bentonite and diatomaceous earth.

[0014] As a further embodiment of the present invention: the organic antioxidant is one of vitamin C, gallic acid, green tea polyphenols and seaweed extract.

[0015] Beneficial effects of the present invention: By adding modified granulating agents, the action time of the fertilizer is effectively increased, and the absorption of fertilizer nutrients by plants is improved. At the same time, the fertilizer has better moisture resistance during direct contact with oxygen, which helps to better preserve and transport it. At the same time, during the use of the fertilizer, the nutrient supply is more sufficient, the action time is longer, the plant's absorption is more sufficient, and the plant grows faster and better. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] The present invention will be further described below in conjunction with the accompanying drawings.

[0017] Figure 1 It is a flow chart of the method of the present invention. DETAILED DESCRIPTION

[0018] The following will be combined with the drawings in 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.

[0019] Embodiment 1 See also Figure 1 As shown, the present invention is a method for preparing liquid fertilizer from isoleucine fermentation broth, comprising the following steps: Step 1: Filtration and impurity removal: Collect the fermentation broth in the isoleucine fermentation tank, which contains multiple components such as amino acids, fermentation residues, microbial cells, inorganic salts, etc., and filter it through a 50μm sieve to remove particles and suspended matter in the fermentation broth, and remove impurities that affect the subsequent preparation process; Step 2: Evaporation and concentration: The filtered fermentation broth is concentrated by low-temperature vacuum evaporation to concentrate the volume of the fermentation broth to 30% of the volume of the original solution, thereby increasing the concentrations of amino acids, minerals and organic matter therein; at this point, the mass percentage of amino acids in the obtained fermentation concentrate is about 5%, of which isoleucine accounts for 30% of the total amino acids.

[0020] Step 3: Nitrogen source optimization: Since the amino acids in the isoleucine fermentation broth are an important source of nitrogen source, an enzyme preparation is added to hydrolyze the long-chain protein in the fermentation broth to decompose it into small-molecule amino acids and / or small-molecule nitrogen compounds; wherein the amount of the enzyme preparation added is 0.02% of the total mass of the fermentation broth, the enzymatic hydrolysis temperature is 35°C, and the enzymatic hydrolysis time is 4 hours; Small molecule amino acids and small molecule nitrogen compounds can be better absorbed by plants; then the pH value of the fermentation liquid is adjusted to 6 by adding acid (such as sulfuric acid) or alkali (such as sodium hydroxide), so that the plants can absorb small molecule amino acids and / or small molecule nitrogen compounds more fully; Step 4: efficacy adjustment: adding potassium compound, phosphide, chelate and enhancer to the fermentation broth, wherein the mass ratio of the fermentation broth, potassium compound, phosphide, chelate and enhancer is: 1000:1:0.5:1:1; The potassium compound is one or both of potassium sulfate and potassium chloride, and the phosphide is potassium dihydrogen phosphate; The chelate is a mixture of chelated iron, chelated zinc and chelated copper, and the mass ratio of chelated iron, chelated zinc and chelated copper is 5:3:2; The enhancer is humic acid; Step 5: Dehydration and drying: Reduce the moisture content in the fermentation liquid by filtering to form a semi-solid fertilizer product, improve the storage stability of the fertilizer, and facilitate application; then dry the semi-solid fertilizer product to obtain powder or granular fertilizer for easy storage and transportation; by spray drying, drum drying and vacuum drying; Step 6: Antioxidant granulation: The dried fertilizer is prepared into granules with a diameter of 2 mm by a granulator; during the granulation process, the modified granulating agent is sprayed on the surface of the formed fertilizer granules for uniform coverage; wherein, the amount of the modified granulating agent added is 2% of the mass of the dried fertilizer; the forming rate and anti-powdering property of the granules are improved; the storage time of the fertilizer is effectively extended and the stability of its nutritional components is maintained; The preparation method of the modified granulating agent is as follows: the granulating agent, organic antioxidant, glycerol, nano-silicon dioxide, starch, mycorrhizal preparation and distilled water are mixed at a ratio of 10:5:25:5:8:1:1000, stirred at a speed of 800r / min, and heated to 60°C to obtain a modified granulating agent solution; glycerol as a plasticizer can make the granulation film more flexible, which is helpful for the stability of the particles during transportation and storage; nano-silicon dioxide helps to improve the waterproofness of the granulation surface film and plays a moisture-proof role; starch can help to slowly release nutrients, increase the duration of nutrient action, and avoid the loss of nutrients due to rapid release; the mycorrhizal preparation can enhance the plant's absorption of nutrients in the soil, especially the utilization efficiency of phosphorus; By adding a modified granulating agent, the action time of the fertilizer is effectively increased, and the absorption of fertilizer nutrients by plants is improved. At the same time, the fertilizer has better moisture resistance during direct contact with oxygen, which helps to better preserve and transport it. At the same time, during the use of the fertilizer, the nutrient supply is more sufficient, the action time is longer, the plant's absorption is more sufficient, and the plant grows faster and better; The granulating agent can be polyvinyl alcohol; the organic antioxidant can be vitamin C.

[0021] Embodiment 2 See also Figure 1 As shown, the present invention is a method for preparing liquid fertilizer from isoleucine fermentation broth, comprising the following steps: Step 1: Filtration and impurity removal: Collect the fermentation broth in the isoleucine fermentation tank, which contains multiple components such as amino acids, fermentation residues, microbial cells, inorganic salts, etc., and filter it through a 50μm sieve to remove particles and suspended matter in the fermentation broth, and remove impurities that affect the subsequent preparation process; Step 2: Evaporation and concentration: The filtered fermentation broth is concentrated by low-temperature vacuum evaporation to concentrate the volume of the fermentation broth to 40% of the volume of the original solution, thereby increasing the concentrations of amino acids, minerals and organic matter therein; at this point, the mass percentage of amino acids in the obtained fermentation concentrate is about 10%, of which isoleucine accounts for 50% of the total amino acids.

[0022] Step 3: Nitrogen source optimization: Since the amino acids in the isoleucine fermentation broth are an important source of nitrogen source, an enzyme preparation is added to hydrolyze the long-chain protein in the fermentation broth to decompose it into small-molecule amino acids and / or small-molecule nitrogen compounds; wherein the amount of the enzyme preparation added is 0.05% of the total mass of the fermentation broth, the enzymatic hydrolysis temperature is 45°C, and the enzymatic hydrolysis time is 6 hours; Small molecule amino acids and small molecule nitrogen compounds can be better absorbed by plants; then the pH value of the fermentation liquid is adjusted to 6-8 by adding acid (such as sulfuric acid) or alkali (such as sodium hydroxide), so that the plants can absorb small molecule amino acids and / or small molecule nitrogen compounds more fully; Step 4: efficacy adjustment: adding potassium compound, phosphide, chelate and enhancer to the fermentation broth, wherein the mass ratio of the fermentation broth, potassium compound, phosphide, chelate and enhancer is: 1000:2:1:5:3; The potassium compound is one or both of potassium sulfate and potassium chloride, and the phosphide is potassium dihydrogen phosphate; The chelate is a mixture of chelated iron, chelated zinc and chelated copper, and the mass ratio of chelated iron, chelated zinc and chelated copper is 5:3:2; The enhancer is humic acid; Step 5: Dehydration and drying: Reduce the moisture content in the fermentation liquid by filtering to form a semi-solid fertilizer product, improve the storage stability of the fertilizer, and facilitate application; then dry the semi-solid fertilizer product to obtain powder or granular fertilizer for easy storage and transportation; by spray drying, drum drying and vacuum drying; Step 6: Antioxidant granulation: The dried fertilizer is prepared into granules with a diameter of 5 mm by a granulator; during the granulation process, the modified granulating agent is sprayed on the surface of the formed fertilizer granules for uniform coverage; wherein, the addition amount of the modified granulating agent is 4% of the mass of the dried fertilizer; the forming rate and anti-powdering property of the granules are improved; the storage time of the fertilizer is effectively extended and the stability of its nutritional components is maintained; The preparation method of the modified granulating agent is as follows: granulating agent, organic antioxidant, glycerol, nano silicon dioxide, starch, mycorrhizal preparation and distilled water are mixed at a ratio of 20:10:35:8:12:3:1000, stirred at a speed of 1000r / min, heated to 70°C, and a modified granulating agent solution is obtained; glycerol as a plasticizer can make the granulation film more flexible, which is helpful for the stability of the particles during transportation and storage; nano silicon dioxide helps to improve the waterproofness of the granulation surface film and plays a moisture-proof role; starch can help to slowly release nutrients, increase the duration of nutrient action, and avoid the loss of nutrients due to rapid release; mycorrhizal preparation can enhance the plant's absorption of nutrients in the soil, especially the utilization efficiency of phosphorus; By adding a modified granulating agent, the action time of the fertilizer is effectively increased, and the absorption of fertilizer nutrients by plants is improved. At the same time, the fertilizer has better moisture resistance during direct contact with oxygen, which helps to better preserve and transport it. At the same time, during the use of the fertilizer, the nutrient supply is more sufficient, the action time is longer, the plant's absorption is more sufficient, and the plant grows faster and better; The granulating agent can be polyvinyl alcohol; the organic antioxidant can be vitamin C.

[0023] Embodiment 3 The enhancer in Example 1 was adjusted to fulvic acid, and other preparation conditions remained unchanged to prepare a fertilizer.

[0024] Embodiment 4 The organic antioxidant in Example 1 was adjusted to green tea polyphenols, and other preparation conditions remained unchanged to prepare a fertilizer.

[0025] Embodiment 5 The granulating agent in Example 1 was adjusted to diatomaceous earth, and other preparation conditions remained unchanged to prepare a fertilizer.

[0026] Embodiment 6 The granulating agent in Example 1 was adjusted to bentonite, the organic antioxidant was adjusted to seaweed extract, and other preparation conditions remained unchanged to prepare a fertilizer.

[0027] Comparative Example 1 A method for preparing liquid fertilizer from isoleucine fermentation broth comprises the following steps: Step 1: Filtration and impurity removal: Collect the fermentation broth in the isoleucine fermentation tank, which contains multiple components such as amino acids, fermentation residues, microbial cells, inorganic salts, etc., and filter it through a 50μm sieve to remove particles and suspended matter in the fermentation broth, and remove impurities that affect the subsequent preparation process; Step 2: Evaporation and concentration: The filtered fermentation broth is concentrated by low-temperature vacuum evaporation to concentrate the volume of the fermentation broth to 30% of the volume of the original solution, thereby increasing the concentrations of amino acids, minerals and organic matter therein; at this point, the mass percentage of amino acids in the obtained fermentation concentrate is about 5%, of which isoleucine accounts for 30% of the total amino acids.

[0028] Step 3: Nitrogen source optimization: Since the amino acids in the isoleucine fermentation broth are an important source of nitrogen source, an enzyme preparation is added to hydrolyze the long-chain protein in the fermentation broth to decompose it into small-molecule amino acids and / or small-molecule nitrogen compounds; wherein the amount of the enzyme preparation added is 0.02% of the total mass of the fermentation broth, the enzymatic hydrolysis temperature is 35°C, and the enzymatic hydrolysis time is 4 hours; Small molecule amino acids and small molecule nitrogen compounds can be better absorbed by plants; then the pH value of the fermentation liquid is adjusted to 6 by adding acid (such as sulfuric acid) or alkali (such as sodium hydroxide), so that the plants can absorb small molecule amino acids and / or small molecule nitrogen compounds more fully; Step 4: efficacy adjustment: adding potassium compound, phosphide, chelate and enhancer to the fermentation broth, wherein the mass ratio of the fermentation broth, potassium compound, phosphide, chelate and enhancer is: 1000:1:0.5:1:1; The potassium compound is one or both of potassium sulfate and potassium chloride, and the phosphide is potassium dihydrogen phosphate; The chelate is a mixture of chelated iron, chelated zinc and chelated copper, and the mass ratio of chelated iron, chelated zinc and chelated copper is 5:3:2; The enhancer is humic acid; Step 5: Dehydration and drying: Reduce the moisture content in the fermentation liquid by filtering to form a semi-solid fertilizer product, improve the storage stability of the fertilizer, and facilitate application; then dry the semi-solid fertilizer product to obtain powder or granular fertilizer for easy storage and transportation; by spray drying, drum drying and vacuum drying; Step 6: Antioxidant granulation: The dried fertilizer is prepared into granules with a diameter of 2 mm by a granulator; during the granulation process, polyvinyl alcohol and vitamin C are sprayed on the surface of the formed fertilizer granules for uniform coverage; the amount of modified granulating agent added is 2% of the mass of the dried fertilizer; the forming rate and anti-powdering property of the granules are improved; the storage time of the fertilizer is effectively extended and the stability of its nutrients is maintained.

[0029] Comparative Example 2 A method for preparing liquid fertilizer from isoleucine fermentation broth comprises the following steps: Step 1: Filtration and impurity removal: Collect the fermentation broth in the isoleucine fermentation tank, which contains multiple components such as amino acids, fermentation residues, microbial cells, inorganic salts, etc., and filter it through a 50μm sieve to remove particles and suspended matter in the fermentation broth, and remove impurities that affect the subsequent preparation process; Step 2: Evaporation and concentration: The filtered fermentation broth is concentrated by low-temperature vacuum evaporation to concentrate the volume of the fermentation broth to 30% of the volume of the original solution, thereby increasing the concentrations of amino acids, minerals and organic matter therein; at this point, the mass percentage of amino acids in the obtained fermentation concentrate is about 5%, of which isoleucine accounts for 30% of the total amino acids.

[0030] Step 3: Nitrogen source optimization: Since the amino acids in the isoleucine fermentation broth are an important source of nitrogen source, an enzyme preparation is added to hydrolyze the long-chain protein in the fermentation broth to decompose it into small-molecule amino acids and / or small-molecule nitrogen compounds; wherein the amount of the enzyme preparation added is 0.02% of the total mass of the fermentation broth, the enzymatic hydrolysis temperature is 35°C, and the enzymatic hydrolysis time is 4 hours; Small molecule amino acids and small molecule nitrogen compounds can be better absorbed by plants; then the pH value of the fermentation liquid is adjusted to 6 by adding acid (such as sulfuric acid) or alkali (such as sodium hydroxide), so that the plants can absorb small molecule amino acids and / or small molecule nitrogen compounds more fully; Step 4: efficacy adjustment: adding potassium compound, phosphide, chelate and enhancer to the fermentation broth, wherein the mass ratio of the fermentation broth, potassium compound, phosphide, chelate and enhancer is: 1000:1:0.5:1:1; The potassium compound is one or both of potassium sulfate and potassium chloride, and the phosphide is potassium dihydrogen phosphate; The chelate is a mixture of chelated iron, chelated zinc and chelated copper, and the mass ratio of chelated iron, chelated zinc and chelated copper is 5:3:2; The enhancer is humic acid; Step 5: Dehydration and drying: Reduce the moisture content in the fermentation liquid by filtering to form a semi-solid fertilizer product, improve the storage stability of the fertilizer, and facilitate application; then dry the semi-solid fertilizer product to obtain powder or granular fertilizer for easy storage and transportation; by spray drying, drum drying and vacuum drying; Step 6: Antioxidant granulation: The dried fertilizer is prepared into granules with a diameter of 2 mm by a granulator.

[0031] The above examples and comparative examples were subjected to comparative experiments: Experiment 1: A plant planting experiment was conducted on Example 1, Example 2, Example 3, Example 4, Example 5, Example 6 and Comparative Example 1 and Comparative Example 2, and the growth height of the plants was measured in the same period of time, and tomatoes were selected as the plants; The specific results of the tomato growth experiment are as follows:

[0032] Based on the above table, it can be concluded that the growth speeds of Example 1, Example 2, Example 3, Example 4, Example 5, and Example 6 are consistent, and are much higher than Comparative Example 1 and Comparative Example 2.

[0033] It can be concluded that by adding modified granulating agents, the absorption and growth of plants are significantly improved, with better effects.

[0034] Experiment 2: A moisture-proof experiment was conducted on Example 1, Example 2, Example 3, Example 4, Example 5, Example 6 and Comparative Example 1 and Comparative Example 2. All fertilizers were placed in an environment with a relative humidity of 60%, and the changes in relative humidity values ​​within the same period of time were measured;

[0035] Based on the above table, it can be concluded that the humidity changes in Example 1, Example 2, Example 3, Example 4, Example 5, and Example 6 are smaller than those in Comparative Example 1 and Comparative Example 2.

[0036] It can be concluded that by adding modified granulating agent, the moisture resistance of fertilizer is better, which is more beneficial for storage and transportation.

[0037] 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 liquid fertilizer from isoleucine fermentation broth, characterized in that: The following steps are involved: Step 1: Filtration and impurity removal: collect the fermentation broth in the isoleucine fermentation tank and filter it through a 50 μm sieve; Step 2: Evaporation and concentration: The filtered fermentation liquid is concentrated by low-temperature vacuum evaporation to concentrate the volume of the fermentation liquid to 30%-40% of the original solution volume; Step 3: Nitrogen source optimization: adding enzyme preparations to hydrolyze long-chain proteins in the fermentation broth; Then, the pH value of the fermentation liquid is adjusted to 6-8 by adding acid or alkali; Step 4: Efficacy adjustment: adding potassium compounds, phosphides, chelates and enhancers to the fermentation broth; Step 5: Dehydration and drying: reduce the water content in the fermentation liquid by filtering to form a semi-solid fertilizer product; then dry the semi-solid fertilizer product to obtain powder or granular fertilizer; Step 6: Antioxidant granulation: The dried fertilizer is prepared into granules with a diameter of 2-5 mm by a granulator; during the granulation process, the modified granulating agent is sprayed on the surface of the formed fertilizer granules for uniform coverage.

2. A method for preparing liquid fertilizer from isoleucine fermentation broth according to claim 1, characterized in that: In the step 3, the amount of enzyme preparation added is 0.02%-0.05% of the total mass of the fermentation liquid, the enzymolysis temperature is 35°C-45°C, and the enzymolysis time is 4-6 hours.

3. The method for preparing liquid fertilizer from isoleucine fermentation broth according to claim 1, characterized in that: In the step 4, the mass ratio of the fermentation liquid, potassium compound, phosphide, chelate and enhancer is: 1000: 1-2: 0.5-1: 1-5: 1-3.

4. The method for preparing liquid fertilizer from isoleucine fermentation broth according to claim 3, characterized in that: In the step 4, the potassium compound is one or both of potassium sulfate and potassium chloride, and the phosphide is potassium dihydrogen phosphate.

5. The method for preparing liquid fertilizer from isoleucine fermentation broth according to claim 3, characterized in that: In the step 4, the chelate is a mixture of chelated iron, chelated zinc and chelated copper, and the mass ratio of chelated iron, chelated zinc and chelated copper is 5:3:

2.

6. The method for preparing liquid fertilizer from isoleucine fermentation broth according to claim 3, characterized in that: The enhancer is one or both of humic acid and fulvic acid.

7. The method for preparing liquid fertilizer from isoleucine fermentation broth according to claim 1, characterized in that: The amount of the modified granulating agent added in step 6 is 2%-4% of the mass of the fertilizer after drying.

8. The method for preparing liquid fertilizer from isoleucine fermentation broth according to claim 1, characterized in that: The preparation method of the modified granulating agent comprises the following steps: mixing the granulating agent, the organic antioxidant, glycerol, nano silicon dioxide, starch, mycorrhizal fungus preparation and distilled water according to the ratio of 10-20: 5-10: 25-35: 5-8: 8-12: 1-3: 1000, stirring at a speed of 800-1000 r / min, and heating to 60-70° C. to obtain a modified granulating agent solution.

9. The method for preparing liquid fertilizer from isoleucine fermentation broth according to claim 8, characterized in that: The granulating agent is one of polyvinyl alcohol, polyethylene glycol, bentonite and diatomaceous earth.

10. The method for preparing liquid fertilizer from isoleucine fermentation broth according to claim 8, characterized in that: The organic antioxidant is one of vitamin C, gallic acid, green tea polyphenols and seaweed extract.

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