Soil and plant growth promoting agent for synthesizing functional groups through enzymolysis of amino acids and preparation method of soil and plant growth promoting agent

Abstract

The invention relates to the related technical field of agricultural fertilizers, in particular to a soil and plant growth promoting agent for synthesizing functional groups through enzymolysis of amino acids and a preparation method, the soil and plant growth promoting agent for synthesizing functional groups through enzymolysis of amino acids comprises the following active ingredients: a) functionalized modified amino acids and / or small molecule peptides consisting of functionalized amino acids; b) unmodified small molecule peptides and free amino acids; and c) a water-soluble organic matter. According to the soil and plant growth promoting agent for synthesizing the functional group through enzymolysis of the amino acid and the preparation method, through biological enzymolysis and functional group modification, the four industrial pains that a traditional amino acid fertilizer is low in activity, difficult to absorb, single in function and limited in raw materials are accurately solved; finally, the invention provides an advanced agricultural input product with multiple advantages of efficient growth promotion, soil improvement and resource circulation.

Description

Technical Field

[0001] This invention relates to the field of agricultural fertilizer technology, and in particular to soil and plant growth promoters that synthesize functional groups by enzymatic hydrolysis of amino acids and their preparation methods. Background Technology

[0002] With the increasing demands for sustainable development and green production in modern agriculture, amino acid fertilizers and growth promoters, as organic nitrogen sources and biostimulants, are being used more and more widely. However, the vast majority of commercially available amino acid products are currently produced using chemical hydrolysis of animal and plant proteins using strong acids or alkalis. This traditional production model has several technical defects that urgently need to be addressed, severely restricting its application effectiveness and development prospects.

[0003] Current technologies have serious shortcomings in the extraction and activity preservation of amino acids. Strong chemical hydrolysis conditions (such as high temperature, strong acid, and strong alkali) easily destroy the natural configuration of amino acids, and completely decompose acid- and alkali-sensitive amino acids such as tryptophan, resulting in a significant reduction in the bioactivity and functionality of the final product. Secondly, the molecular structure of existing products is unreasonable, leading to difficulties in crop absorption and limited functionality. Traditional processes yield a mixture of amino acids with a wide molecular weight distribution and large peptides, with a low proportion of small molecules that plants can directly absorb and utilize. More importantly, their molecular structures are not designed to fit the transport mechanisms of plant cell membranes, creating an "absorption barrier." This limits the product's function to providing nitrogen nutrition rather than acting as a precise "signaling molecule" to actively regulate plant physiological metabolism, activate its growth potential, or effectively improve the soil microecological environment. Furthermore, current technologies have shortcomings in raw material utilization and environmental protection. Many products rely on a single source of raw materials, resulting in high costs, and fail to fully utilize protein-rich agricultural and slaughtering processing byproducts such as soybean meal, corn steep liquor, feather meal, and blood meal. This not only wastes resources, but also makes the disposal of related waste an environmental burden. Summary of the Invention

[0004] The purpose of this invention is to provide soil and plant growth promoters that synthesize functional groups from enzymatically hydrolyzed amino acids and their preparation methods, in order to solve the problems of low activity, difficult absorption, single function, and insufficient utilization of raw materials that are common in existing amino acid fertilizers.

[0005] To achieve the above objectives, the present invention provides the following technical solution: a soil and plant growth promoter that synthesizes functional groups from enzymatically hydrolyzed amino acids, wherein the active ingredients include:

[0006] a) Functionalized amino acids and / or small peptides composed of functionalized amino acids; b) Unmodified small peptides and free amino acids; c) Water-soluble organic matter;

[0007] The functionalized amino acids are formed by introducing one or more functional groups, such as hydroxyl, carboxyl, thiol, acyl, alkyl or glycosyl, into the side chain of the amino acid molecule. The molecular weight of the small peptides and free amino acids is less than 1000 Daltons. The water-soluble organic matter is derived from one or more of the following: soluble sugars, organic acids, and humic acid precursors (phenols, quinones) produced during enzymatic hydrolysis.

[0008] Preferably, the functionalized amino acids include acylated lysine and / or carboxymethylated cysteine.

[0009] Preferably, the growth promoter is in the form of liquid, powder, granules or column.

[0010] A method for preparing soil and plant growth promoters by enzymatic hydrolysis of amino acids to synthesize functional groups includes the following steps:

[0011] a) Raw material pretreatment: Cleaning, crushing and sterilizing protein-rich animal and plant raw materials;

[0012] b) Targeted enzymatic hydrolysis: The pretreated raw materials are mixed with water in a certain proportion, and a compound biological enzyme preparation is added. The stepwise enzymatic hydrolysis reaction is carried out under the conditions of 45-60℃ and pH 6.0-9.0, and then the enzyme is inactivated to obtain the enzymatic hydrolysate.

[0013] c) Separation and enrichment: The enzymatic hydrolysate is subjected to solid-liquid separation and membrane separation to collect and enrich components with a molecular weight of less than 1000 Daltons to obtain an amino acid enrichment solution.

[0014] d) Functional group synthesis and modification: Functional group reagents and coupling agents are added to the amino acid enrichment solution, and functionalization modification reaction is carried out under the conditions of 30-40℃ and pH 7.5-9.5 to obtain functionalized amino acid concentrate.

[0015] e) Finished product preparation: The functionalized amino acid concentrate is processed into liquid, powder, granules or columnar finished products as required.

[0016] Preferably, in step a):

[0017] The plant and animal raw materials include plant-derived raw materials and animal-derived raw materials;

[0018] The plant-derived raw materials are selected from one or more of soybean meal, corn steep liquor, wheat bran, rice husk, and straw;

[0019] The animal-derived raw materials are selected from one or more of feather meal, blood meal, hoof and horn meal, offal, and bone residue.

[0020] Preferably, in step b):

[0021] The stepwise enzymatic hydrolysis reaction is as follows: First, under the conditions of pH 8.5-9.5 and temperature 50-55℃, alkaline protease is used to carry out the first stage of enzymatic hydrolysis for 2-3 hours. Then, the pH is adjusted to 6.5-7.5 and the temperature is 45-50℃, and flavor protease or collagenase is added to carry out the second stage of enzymatic hydrolysis for 3-4 hours.

[0022] Preferably, in step c):

[0023] The membrane separation includes ultrafiltration using an ultrafiltration membrane with a molecular weight cutoff of 1000 Daltons and nanofiltration concentration using a nanofiltration membrane with a molecular weight cutoff of 500 Daltons. The enrichment is achieved by selectively enriching one or more of tryptophan, proline, lysine, and sulfur-containing amino acids using ion exchange chromatography.

[0024] Preferably, in step d):

[0025] The functional group reagent is one of ethylene oxide, succinic anhydride or citric anhydride, and the functionalization modification reaction is an acylation reaction of the ε-amino group of lysine or a carboxymethylation reaction of the thiol group of cysteine.

[0026] Preferably, in step e):

[0027] The powder is processed using spray drying technology, with the inlet temperature controlled at 180℃ and the outlet temperature controlled at 80℃. The granular or columnar fertilizer is processed by mixing the concentrated liquid with bentonite or zeolite powder carrier and then granulating or extruding it.

[0028] Compared with the prior art, the beneficial effects of the present invention are:

[0029] 1. By using compound bio-enzymes to perform targeted stepwise enzymatic hydrolysis of diversified agricultural by-products such as soybean meal and feather meal, the destruction of amino acid configuration caused by traditional chemical hydrolysis is overcome, and the biologically active L-type amino acids are preserved to the maximum extent.

[0030] 2. By using the core technology of functional group modification, the amino acids obtained by enzymatic hydrolysis are precisely designed and modified at the molecular level (e.g., acylation of the ε-amino group of lysine and carboxymethylation of the thiol group of cysteine). This not only significantly improves their water solubility and stability, but also makes their molecular structure more compatible with the transport mechanism of the cell membrane, thereby fundamentally solving the industry problem of low amino acid absorption efficiency in traditional products.

[0031] 3. Functionally modified amino acids are no longer just nutrients; they can also act as highly efficient biological signaling molecules, directly activating stem cells in plant stems, promoting cell division and differentiation, and strongly stimulating root development. At the same time, the small molecule peptides and water-soluble organic matter in the product can synergistically optimize the soil micro-ecological environment, specifically promote the proliferation of beneficial microbial communities, improve soil aggregate structure, and alleviate compaction problems. Ultimately, this product achieves multiple outstanding effects, including highly efficient plant growth promotion, deep soil improvement, and resource recycling of agricultural waste, successfully breaking through the technical bottlenecks of existing amino acid fertilizers, such as single function, low activity, and poor environmental compatibility. Detailed Implementation

[0032] The technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of them. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0033] The embodiments of the present invention are described below. These embodiments are exemplary and are only used to explain the present invention, and should not be construed as limiting the present invention. Where no specific technical or technical conditions are specified in the embodiments, they shall be carried out in accordance with the technical or technical conditions described in the literature in the field or in accordance with the product instructions. Where the manufacturers of the reagents or instruments used are not specified, they are all conventional products that can be obtained commercially.

[0034] Soil and plant growth promoters that synthesize functional groups from enzymatically hydrolyzed amino acids, their active ingredients include:

[0035] a) Functionalized amino acids and / or small peptides composed of functionalized amino acids; b) Unmodified small peptides and free amino acids; c) Water-soluble organic matter;

[0036] The functionalized amino acids are formed by introducing one or more functional groups, such as hydroxyl, carboxyl, thiol, acyl, alkyl or glycosyl, into the side chain of the amino acid molecule. The molecular weight of the small peptides and free amino acids is less than 1000 Daltons. The water-soluble organic matter is derived from one or more of the following: soluble sugars, organic acids, and humic acid precursors (phenols, quinones) produced during enzymatic hydrolysis.

[0037] Furthermore, the functionalized amino acids include acylated lysine and / or carboxymethylated cysteine.

[0038] Furthermore, the growth promoter is in the form of liquid, powder, granules, or column.

[0039] A method for preparing soil and plant growth promoters by enzymatic hydrolysis of amino acids to synthesize functional groups includes the following steps:

[0040] a) Raw material pretreatment: Cleaning, crushing and sterilizing protein-rich animal and plant raw materials;

[0041] b) Targeted enzymatic hydrolysis: The pretreated raw materials are mixed with water in a certain proportion, and a compound biological enzyme preparation is added. The stepwise enzymatic hydrolysis reaction is carried out under the conditions of 45-60℃ and pH 6.0-9.0 (the pH is adjusted by using dilute acid (such as hydrochloric acid) or dilute alkali (such as sodium hydroxide) solution). Then the enzyme is inactivated to obtain the enzymatic hydrolysate.

[0042] c) Separation and enrichment: The enzymatic hydrolysate is subjected to solid-liquid separation and membrane separation to collect and enrich components with a molecular weight of less than 1000 Daltons to obtain an amino acid enrichment solution.

[0043] d) Functional group synthesis and modification: Functional group reagents and coupling agents are added to the amino acid enrichment solution, and functionalization modification reaction is carried out under the conditions of 30-40℃ and pH 7.5-9.5 to obtain functionalized amino acid concentrate.

[0044] e) Finished product preparation: The functionalized amino acid concentrate is processed into liquid, powder, granules or columnar finished products as required.

[0045] Furthermore, in step a):

[0046] The plant and animal raw materials include plant-derived raw materials and animal-derived raw materials;

[0047] The plant-derived raw materials are selected from one or more of soybean meal, corn steep liquor, wheat bran, rice husk, and straw;

[0048] The animal-derived raw materials are selected from one or more of feather meal, blood meal, hoof and horn meal, offal, and bone residue.

[0049] Furthermore, in step b):

[0050] The stepwise enzymatic hydrolysis reaction is as follows: First, under the conditions of pH 8.5-9.5 and temperature 50-55℃, alkaline protease is used to carry out the first stage of enzymatic hydrolysis for 2-3 hours. Then, the pH is adjusted to 6.5-7.5 and the temperature is 45-50℃, and flavor protease or collagenase is added to carry out the second stage of enzymatic hydrolysis for 3-4 hours.

[0051] Furthermore, in step c):

[0052] The membrane separation includes ultrafiltration using an ultrafiltration membrane with a molecular weight cutoff of 1000 Daltons and nanofiltration concentration using a nanofiltration membrane with a molecular weight cutoff of 500 Daltons. The enrichment is achieved by selectively enriching one or more of tryptophan, proline, lysine, and sulfur-containing amino acids using ion exchange chromatography.

[0053] Furthermore, in step d):

[0054] The functional group reagent is one of ethylene oxide, succinic anhydride or citric anhydride, and the functionalization modification reaction is an acylation reaction of the ε-amino group of lysine or a carboxymethylation reaction of the thiol group of cysteine.

[0055] Furthermore, in step e):

[0056] The powder is processed using spray drying technology, with the inlet temperature controlled at 180℃ and the outlet temperature controlled at 80℃. The granular or columnar fertilizer is processed by mixing the concentrated liquid with bentonite or zeolite powder carrier and then granulating or extruding it.

[0057] Example 1: Preparation of a liquid growth promoter based on soybean meal and feather meal

[0058] This embodiment details a specific preparation method of the "soil and plant growth promoter with functional group synthesized by enzymatic hydrolysis of amino acids" described in this invention, and the final product is a liquid dosage form.

[0059] 1. Raw material pretreatment

[0060] Plant-derived raw material: Take 50 kg of dried soybean meal (a byproduct of soybean oil extraction);

[0061] Animal-derived raw materials: 20 kg of high-temperature sterilized feather powder (a byproduct of poultry feather processing);

[0062] Processing procedure: Mix soybean meal and feather meal, grind them into a particle size of about 60 mesh using a grinder, and then sterilize them with steam at 121°C for 30 minutes to kill off bacteria and ensure the purity and safety of the subsequent enzymatic hydrolysis process.

[0063] 2. Targeted enzymatic hydrolysis

[0064] Mixing: Add the pretreated mixed raw materials and 200 kg of pure water into the enzymatic hydrolysis reactor, stir evenly to form a slurry;

[0065] The first stage of enzymatic hydrolysis: The pH of the slurry was adjusted to 9.0 with dilute sodium hydroxide solution, and the temperature was raised to 52°C. Then, 1.5% (by weight of the total raw material) of alkaline protease (e.g., produced by Bacillus licheniformis) was added, and the mixture was kept at a constant temperature with stirring for 2.5 hours under these conditions. This stage aims to utilize the high activity of alkaline protease under slightly alkaline conditions to rapidly cleave peptide bonds in protein molecules, generating medium-sized peptides.

[0066] Second stage of enzymatic hydrolysis: After the first stage of enzymatic hydrolysis, the pH of the system was adjusted to 7.0 with dilute hydrochloric acid solution, and the temperature was lowered to 48°C. Then, 1.0% of the total weight of the raw materials was added with flavor protease (a complex protease composed of endonucleases and exonucleases). Under these conditions, the mixture was kept at a constant temperature and stirred for 3.5 hours for enzymatic hydrolysis. In this stage, the flavor protease further hydrolyzes the peptides into smaller peptides and free amino acids.

[0067] Enzyme inactivation: After the enzymatic hydrolysis is completed, the reaction system is heated to 90°C and maintained for 15 minutes to denature and inactivate the enzyme protein, thereby terminating the reaction and obtaining the enzymatic hydrolysate.

[0068] 3. Separation and Enrichment

[0069] Solid-liquid separation: The above enzymatic hydrolysate is separated by a plate and frame filter or centrifuge to remove the undigested residue and obtain a clear enzymatic hydrolysate.

[0070] Membrane separation and enrichment:

[0071] Ultrafiltration: The enzymatic hydrolysate is pumped into an ultrafiltration membrane system with a molecular weight cutoff of 1000 Daltons, and the permeate is collected. This step aims to remove large peptides with a molecular weight greater than 1000 Daltons and residual impurities, ensuring that the molecular weight of the core active component meets the requirements (less than 1000 Daltons).

[0072] Nanofiltration concentration: The ultrafiltration permeate is pumped into a nanofiltration membrane system with a molecular weight cutoff of 500 Daltons for dehydration and concentration. This step can remove some water while retaining small molecule peptides and amino acids to obtain an amino acid enriched solution (concentrated about 5 times).

[0073] Selective enrichment: To further enhance the content of specific functional amino acids (such as tryptophan and proline, which promote stem cell activity, as well as easily modified lysine and sulfur-containing amino acids), the amino acid enrichment solution can be treated with a weakly acidic cation exchange resin. Selective adsorption and elution are achieved by adjusting the pH, thus enabling further enrichment of the target amino acids.

[0074] 4. Functional group synthesis and modification

[0075] Reaction preparation: Take 100 liters of the enriched amino acid solution and place it in a reaction vessel equipped with stirring and temperature control. Adjust the system temperature to 35°C and the pH to 8.5;

[0076] Functional group modification: Under uniform stirring, 2.0 kg of succinic anhydride (functional group reagent) and 0.5 kg of 1-ethyl-(3-dimethylaminopropyl)carbodiimide hydrochloride (EDC) as coupling agent were slowly added;

[0077] Reaction mechanism: Succinic anhydride primarily targets lysine molecules in the enrichment solution, undergoing an acylation reaction with the ε-amino group of its side chain, thereby attaching an additional carboxyl functional group (-COOH) to lysine. This modification significantly enhances the water solubility and electronegativity of amino acid molecules, making them more easily recognized and absorbed by transport proteins on plant root cell membranes, overcoming the traditional barrier to amino acid absorption.

[0078] Reaction process: The reaction was maintained at 35°C and pH 8.5 for 4 hours to ensure complete reaction. After the reaction was completed, a concentrated solution of functionalized amino acids was obtained.

[0079] 5. Finished Product Preparation

[0080] After testing the above-mentioned functionalized amino acid concentrate (mainly testing the content of functionalized amino acids, small molecule peptides, pH value, specific gravity, etc.), it can be directly packaged as a liquid product. Alternatively, appropriate amounts of preservatives (such as potassium sorbate) and surfactants can be added as needed to enhance stability, ultimately producing a liquid soil and plant growth promoter.

[0081] Example 2: Preparation of a powdered growth promoter based on corn steep liquor and blood meal

[0082] This embodiment demonstrates a method for preparing a powdered growth promoter using corn steep liquor and blood meal as the main raw materials.

[0083] 1. Raw material pretreatment

[0084] Plant-derived raw materials: 80 kg of corn steep liquor (containing approximately 40% solids), a byproduct of wet starch production;

[0085] Animal-derived raw materials: 15 kg of spray-dried blood meal (animal slaughter by-product);

[0086] Processing procedure: Mix blood meal with corn syrup. Since corn syrup is already in a slurry consistency, no additional water needs to be added. After stirring evenly, perform steam sterilization (121℃, 30 minutes).

[0087] 2. Targeted enzymatic hydrolysis

[0088] After sterilization, cool to 50°C. Proceed directly with enzymatic hydrolysis; no additional pH adjustment is required (corn steep liquor is inherently weakly acidic).

[0089] Stepwise enzymatic hydrolysis: First, add 1.0% collagenase (targeting collagen in blood meal) and hydrolyze for 3 hours at pH 7.5 and 48℃. Then, add 0.8% acidic protease and hydrolyze for 2 hours at pH 5.5 and 45℃ to adapt to the acidic environment of corn steep liquor and completely hydrolyze the protein.

[0090] Enzyme inactivation: Same as in Example 1, the enzyme is inactivated by heating to 90°C and maintaining it for 15 minutes without affecting the amino acid activity.

[0091] 3. Separation and Enrichment

[0092] After solid-liquid separation, the enzymatic hydrolysate was passed sequentially through a 1000 Dalton ultrafiltration membrane and a 500 Dalton nanofiltration membrane to obtain an amino acid enrichment solution.

[0093] 4. Functional group synthesis and modification

[0094] In an amino acid enrichment solution, ethylene oxide was added as a functional group reagent at pH 9.0 and 38°C to hydroxyethylate the thiol group (-SH) of cysteine, introducing a hydroxyl functional group (-OH).

[0095] 5. Finished Product Preparation

[0096] Functionalized amino acid concentrate is made into powder using spray drying technology. The inlet temperature of the spray drying tower is controlled at 180℃ and the outlet temperature is controlled at 80℃. This mild drying condition helps to protect the bioactivity of heat-sensitive functionalized amino acids and small molecule peptides, and finally obtains a free-flowing powdered growth promoter, which is convenient for transportation, storage and mixing with other fertilizers.

[0097] Example 3: Preparation of particulate growth promoters based on multiple byproducts

[0098] This embodiment demonstrates a scheme for preparing granular slow-release fertilizer using various industrial and agricultural by-products.

[0099] 1. Raw materials: A mixture of soybean meal, wheat bran, bone meal, and offal powder.

[0100] 2. Enzymatic hydrolysis and modification: The process flow is similar to that in Example 1. After directional enzymatic hydrolysis and membrane separation enrichment, citric anhydride is used to modify the amino acids, introducing multiple carboxyl and hydroxyl groups.

[0101] 3. Granulation: The obtained functionalized amino acid concentrate is mixed with porous carrier bentonite in a certain ratio (e.g., 1:0.5) in a mixer, and then extruded and granulated using a granulator to produce particles with a diameter of about 3-5 mm.

[0102] 4. Drying: Dry with low-temperature airflow (<70℃) until the moisture content is within acceptable limits.

[0103] Granular products have a slow-release effect, with functionalized amino acids and organic matter slowly released with water, continuously acting on the soil and crop roots, making them particularly suitable for basal application. Bentonite carriers can also further improve the soil's water and fertilizer retention capacity.

[0104] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A soil and plant growth promoter that synthesizes functional groups from enzymatically hydrolyzed amino acids, characterized in that, Its active ingredients include: a) Functionalized amino acids and / or small peptides composed of functionalized amino acids; b) Unmodified small peptides and free amino acids; c) Water-soluble organic matter; The functionalized amino acids are formed by introducing one or more functional groups, such as hydroxyl, carboxyl, thiol, acyl, alkyl or glycosyl, into the side chain of the amino acid molecule. The molecular weight of the small peptides and free amino acids is less than 1000 Daltons. The water-soluble organic matter is derived from one or more of the following: soluble sugars, organic acids, and humic acid precursors (phenols, quinones) produced during enzymatic hydrolysis.

2. The soil and plant growth promoter that synthesizes functional groups from enzymatically hydrolyzed amino acids according to claim 1, characterized in that, The functionalized amino acids include acylated lysine and / or carboxymethylated cysteine.

3. The soil and plant growth promoter that synthesizes functional groups from enzymatically hydrolyzed amino acids according to claim 1, characterized in that, The growth promoter is available in liquid, powder, granule, or column form.

4. A method for preparing a soil and plant growth promoter that synthesizes functional groups from enzymatically hydrolyzed amino acids as described in any one of claims 1-3, characterized in that, Includes the following steps: a) Raw material pretreatment: Cleaning, crushing and sterilizing protein-rich animal and plant raw materials; b) Targeted enzymatic hydrolysis: The pretreated raw materials are mixed with water in a certain proportion, and a compound biological enzyme preparation is added. The stepwise enzymatic hydrolysis reaction is carried out under the conditions of 45-60℃ and pH 6.0-9.0, and then the enzyme is inactivated to obtain the enzymatic hydrolysate. c) Separation and enrichment: The enzymatic hydrolysate is subjected to solid-liquid separation and membrane separation to collect and enrich components with a molecular weight of less than 1000 Daltons to obtain an amino acid enrichment solution. d) Functional group synthesis and modification: Functional group reagents and coupling agents are added to the amino acid enrichment solution, and functionalization modification reaction is carried out under the conditions of 30-40℃ and pH 7.5-9.5 to obtain functionalized amino acid concentrate. e) Finished product preparation: The functionalized amino acid concentrate is processed into liquid, powder, granules or columnar finished products as required.

5. The method for preparing soil and plant growth promoters that synthesize functional groups from enzymatically hydrolyzed amino acids according to claim 4, characterized in that, In step a): The plant and animal raw materials include plant-derived raw materials and animal-derived raw materials; The plant-derived raw materials are selected from one or more of soybean meal, corn steep liquor, wheat bran, rice husk, and straw; The animal-derived raw materials are selected from one or more of feather meal, blood meal, hoof and horn meal, offal, and bone residue.

6. The method for preparing soil and plant growth promoters that synthesize functional groups from enzymatically hydrolyzed amino acids according to claim 4, characterized in that, In step b): The stepwise enzymatic hydrolysis reaction is as follows: First, under the conditions of pH 8.5-9.5 and temperature 50-55℃, alkaline protease is used to carry out the first stage of enzymatic hydrolysis for 2-3 hours. Then, the pH is adjusted to 6.5-7.5 and the temperature is 45-50℃, and flavor protease or collagenase is added to carry out the second stage of enzymatic hydrolysis for 3-4 hours.

7. The method for preparing soil and plant growth promoters that synthesize functional groups from enzymatically hydrolyzed amino acids according to claim 4, characterized in that, In step c): The membrane separation includes ultrafiltration using an ultrafiltration membrane with a molecular weight cutoff of 1000 Daltons and nanofiltration concentration using a nanofiltration membrane with a molecular weight cutoff of 500 Daltons. The enrichment is achieved by selectively enriching one or more of tryptophan, proline, lysine, and sulfur-containing amino acids using ion exchange chromatography.

8. The method for preparing soil and plant growth promoters that synthesize functional groups from enzymatically hydrolyzed amino acids according to claim 4, characterized in that, In step d): The functional group reagent is one of ethylene oxide, succinic anhydride or citric anhydride, and the functionalization modification reaction is an acylation reaction of the ε-amino group of lysine or a carboxymethylation reaction of the thiol group of cysteine.

9. The method for preparing soil and plant growth promoters that synthesize functional groups from enzymatically hydrolyzed amino acids according to claim 4, characterized in that, In step e): The powder is processed using spray drying technology, with the inlet temperature controlled at 180℃ and the outlet temperature controlled at 80℃. The granular or columnar fertilizer is processed by mixing the concentrated liquid with bentonite or zeolite powder carrier and then granulating or extruding it.