Liquid amino acid fertilizer and method for preparing the same

Abstract

This invention relates to the field of amino acid fertilizer technology, specifically disclosing a liquid amino acid fertilizer and its preparation method. Specifically, a carbon source, calcium agent, and pH adjuster are added to the inactivated threonine final mother liquor to obtain a fermentation broth; a compound microbial fermentation agent is prepared by combining Bacillus subtilis, Bacillus licheniformis, and Bacillus amyloliquefaciens; the compound microbial fermentation agent is added to the fermentation broth for fermentation treatment, followed by the addition of a cell protectant to obtain the liquid amino acid fertilizer. This invention transforms the waste threonine final mother liquor from fermentation into a valuable resource, reusing it in fermentation fertilizer production. Combined with the compound microbial agent and other agents for synergistic fermentation, the resulting fertilizer final product not only provides rich nutrients for crops but also reduces soil hardness, increases soil softness, and increases soil organic matter content.

Description

Technical Field

[0001] This invention relates to the field of amino acid fertilizer technology, specifically to a liquid amino acid fertilizer and its preparation method. Background Technology

[0002] In the field of fertilizer preparation technology, there are already various existing methods for preparing high-efficiency fertilizers using organic waste as raw materials. For example, patent CN106588386A discloses a method for harmlessly treating antibiotic fermentation residue that can be used to manufacture organic fertilizer. Although it shows that fermentation residue can be used as a raw material for organic fertilizer due to its high organic content, the residue needs to be chemically detoxified with an oxidant to remove antibiotic residues, which can easily cause secondary pollution and increase the complexity of subsequent processing. Patent CN104817376A discloses a bio-organic fertilizer prepared using lysine waste mother liquor. Through ammoniation and granulation technology, it prepares high-purity protein and feed while preparing organic fertilizer, and the preparation process is environmentally friendly and pollution-free. However, the preparation of this bio-organic fertilizer requires steps such as filtration, evaporation, crystallization, and biochemical treatment, which is complex and costly. Existing methods for using amino acid waste liquid to prepare organic fertilizer have problems such as high antibiotic and heavy metal residues, insufficient nutrient content, complex treatment processes, and high costs. Summary of the Invention

[0003] To address the aforementioned technical problems, this invention provides a liquid amino acid fertilizer and its preparation method. Organic fertilizer is prepared using fermented amino acid mother liquor as a specific raw material. This fermented amino acid mother liquor contains various complex nutrients and has very low levels of harmful substances such as heavy metals and antibiotics. Using it as a raw material for bio-organic fertilizer can effectively improve fertilizer quality, promote crop growth, and achieve efficient resource utilization. By using the fermented amino acid mother liquor as a culture medium raw material, combined with composting using beneficial microorganisms, a nutrient-rich and high-quality fertilizer can be prepared, enhancing crop growth.

[0004] To achieve the above objectives, the present invention provides the following technical solution:

[0005] In a first aspect, the present invention provides a method for preparing a liquid amino acid fertilizer, comprising the following steps:

[0006] Carbon source, calcium agent and pH adjuster were added to the final mother liquor of inactivated threonine to obtain fermentation broth;

[0007] Bacillus subtilis, Bacillus licheniformis and Bacillus amyloliquefaciens were formulated into a compound microbial fermentation agent;

[0008] Add a compound microbial fermentation agent to the fermentation broth for fermentation treatment, and then add a cell protectant to obtain liquid amino acid fertilizer.

[0009] Optionally, the carbon source is glucose, and the amount of carbon source added is 100 g / L to 300 g / L based on the volume of the final mother liquor of inactivated threonine; the calcium agent is quicklime, and the amount of quicklime added is 8 g / L to 30 g / L based on the volume of the final mother liquor of inactivated threonine.

[0010] Optionally, the pH adjuster is sodium hydroxide, and the pH value of the fermentation broth is 6.5~7.5.

[0011] Optionally, the fermentation treatment temperature is 30℃~37℃ and the time is 32h~46h.

[0012] Optionally, the amount of compound microbial fermentation agent added is 0.8wt% to 3wt% based on the mass of the fermentation broth.

[0013] Optionally, in the compound microbial fermentation agent, the ratio of the effective viable number of Bacillus subtilis, Bacillus licheniformis and Bacillus amyloliquefaciens is 1:1:1.

[0014] Optionally, the inactivation treatment of the final amino acid mother liquor is maintained at 70°C for 20 to 30 minutes.

[0015] Optionally, the cell protectant includes trehalose and vitamin C.

[0016] Optionally, based on the mass of the fermentation broth, the amount of trehalose added is 4wt%~6wt%, and the amount of vitamin C added is 0.1wt%~0.3wt%.

[0017] Secondly, the present invention also provides a liquid amino acid fertilizer, which is prepared by the above method.

[0018] Compared with the prior art, the present invention has at least the following beneficial effects:

[0019] This invention uses threonine final mother liquor as the core raw material. After inactivation treatment, carbon source, calcium agent, and pH adjuster are added to optimize the fermentation environment. A compound microbial fermentation agent composed of Bacillus subtilis, Bacillus licheniformis, and Bacillus amyloliquefaciens is introduced for synergistic fermentation. Finally, a cell protectant is added to successfully prepare liquid amino acid fertilizer. The threonine final mother liquor, rich in amino acids, organic matter, and trace elements with extremely low heavy metal and antibiotic residues, can be directly used for organic fertilizer fermentation without complex pretreatment. Through synergistic fermentation with the compound microbial fermentation agent, the effective nitrogen, phosphorus, potassium, and organic matter content in the organic fertilizer are further increased, and it also endows the fertilizer with the functions of inhibiting pathogens and promoting crop growth, solving the problems of incomplete nutrition and poor soil improvement effects of traditional organic fertilizers. This invention realizes the resource utilization of industrial waste. The preparation process is simple, environmentally friendly, and low-cost. The resulting liquid amino acid fertilizer is rich in nutrients and has diverse functions, significantly improving soil structure, increasing soil organic matter and humic acid content, promoting crop growth and quality improvement, and has good ecological benefits and promising prospects for widespread application. Attached Figure Description

[0020] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0021] Figure 1 This is a process flow diagram for preparing liquid amino acid fertilizer according to an embodiment of the present invention. Detailed Implementation

[0022] The specific embodiments of the present invention are described in detail below, but it should be understood that the scope of protection of the present invention is not limited to the specific embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention. Unless otherwise specified, the experimental methods described in the embodiments of the present invention are conventional methods, and the materials and reagents used in the following embodiments are commercially available unless otherwise specified.

[0023] This invention provides a method for preparing liquid amino acid fertilizer, such as... Figure 1As shown, the final amino acid mother liquor (threonine fermentation waste liquid; the threonine fermentation process can be carried out using conventional techniques in this field) is inactivated by heating at 70°C for 25 minutes, and then mixed with a compound microbial fermentation agent for fermentation to obtain fermented amino acid fertilizer. The final amino acid mother liquor contains residual amino acids, microbial proteins, organic acids, polysaccharides, inorganic salts such as potassium and magnesium, and various unutilized nutrients. The specific steps are as follows:

[0024] Step 1: Determine the basic indicators such as total nitrogen, hydrolyzable nitrogen, organic matter, and heavy metals in the final mother liquor of the inactivated amino acids. The results are shown in Tables 1 and 2. Based on the volume of the final mother liquor of the inactivated amino acids, add 100g / L~300g / L glucose and 8g / L~30g / L quicklime to the final mother liquor of the inactivated amino acids, mix to form a fermentation medium, and adjust the pH to 6.5~7.5 with sodium hydroxide to obtain the fermentation broth; preferably, add 200g / L glucose and 10g / L quicklime to the final mother liquor of the inactivated amino acids, and adjust the pH to 7.0 with sodium hydroxide. Quicklime, specification 500g, model 10005918, brand Guoyao.

[0025] Step 2: Prepare a compound microbial fermentation agent by mixing Bacillus subtilis, Bacillus licheniformis, and Bacillus amyloliquefaciens in a certain proportion; preferably, the ratio of the effective viable counts of Bacillus subtilis, Bacillus licheniformis, and Bacillus amyloliquefaciens powder in the compound microbial fermentation agent is 1:1:1, and the bacterial count of the compound microbial fermentation agent is 5 billion / g.

[0026] The compound microbial fermentation agent consists of plant rhizosphere growth-promoting bacteria, all of which are environmentally friendly and non-toxic probiotic strains. Specifically, *Bacillus subtilis* (1 kg / packet), with an effective viable count ≥ 50 billion / g, produces various active substances, inhibits pathogenic bacteria, degrades phytate, and promotes plant growth; this *Bacillus subtilis* strain was purchased externally from Zhengzhou Zhongke Chemical Products Co., Ltd. *Bacillus amyloliquefaciens* (1 kg / packet), with an effective viable count ≥ 20 billion / g, also promotes growth, produces antibacterial substances, and inhibits soil-borne pathogens; this *Bacillus amyloliquefaciens* strain was purchased externally from Yangzhou Herrenknecht Biotechnology Co., Ltd. Bacillus licheniformis: 500g / pack, effective live bacteria count ≥2 billion / g. Bacillus licheniformis can induce plant resistance and promote the production of antibacterial active substances to kill pests and diseases. It has a unique biological oxygen-scavenging mechanism, inhibiting the growth and colonization of pathogens. It can produce a variety of antibiotics and has a good inhibitory effect on a variety of pathogens. The Bacillus licheniformis strain mentioned above was purchased externally from Beihai Yeshengwang Biotechnology Co., Ltd.

[0027] Step 3: Based on the mass of the fermentation broth, add 0.8wt%~3wt% of the compound microbial fermentation agent to the fermentation broth and ferment at 30℃~37℃ for 32h~46h. After fermentation, add 4wt%~6wt% trehalose and 0.1wt%~0.3wt% vitamin C, and package to obtain liquid amino acid fertilizer; preferably, the amount of the compound microbial fermentation agent added is 1wt%, the fermentation conditions are 35℃ for 40h, and after fermentation, add 5% trehalose and 0.2% vitamin C.

[0028] A comparative experiment on the fertilizer efficacy of amino acid fertilizer was conducted on potted lettuce under natural sunlight and greenhouse conditions. The liquid amino acid fertilizer provided by this invention was used as the experimental group, ordinary commercially available amino acid fertilizer as the control group, and no fertilizer was applied as a blank control. By comparing the growth of lettuce in different groups, it was found that the liquid amino acid fertilizer provided by this invention has better fertilizer efficacy, significantly increasing soil organic matter and humic acid content. The total nitrogen, total phosphorus, and total potassium contents all meet the requirements of compound microbial fertilizers, and some indicators are significantly better than conventional compound organic fertilizers. It can significantly increase lettuce yield and improve its nutritional value, significantly increasing the content of protein, vitamin C, and trace elements such as calcium, potassium, phosphorus, and iron in lettuce.

[0029] Furthermore, the production method of the liquid amino acid fertilizer of the present invention is simple, low-cost, safe and friendly to humans, animals and the environment, and turns the final mother liquor of fermented amino acids into a valuable resource, which meets the application needs of modern technology and agricultural development.

[0030] Example 1

[0031] A method for preparing a liquid amino acid fertilizer includes the following steps:

[0032] The final amino acid mother liquor (threonine fermentation waste liquor) was heated at 70℃ for 25 minutes to inactivate it. Based on the volume of the final amino acid mother liquor, 200 g / L of glucose and 10 g / L of quicklime were added to the inactivated final amino acid mother liquor. After mixing, a fermentation culture medium was formed. The pH value was adjusted to 7.0 with sodium hydroxide to obtain the fermentation broth.

[0033] Bacillus subtilis, Bacillus licheniformis, and Bacillus amyloliquefaciens were formulated into a compound microbial fermentation agent with an effective viable count ratio of 1:1:1, and the microbial count of the compound microbial fermentation agent was 5 billion / g.

[0034] Based on the mass of the fermentation liquid, the compound microbial fermentation agent was added to 50 kg of fermentation liquid at a dosage of 1 wt%, aerated, and fermented at 35℃ for 40 h. After fermentation, 5 wt% trehalose and 0.2 wt% vitamin C were added, and the mixture was packaged to obtain liquid amino acid fertilizer.

[0035] The nitrogen, phosphorus, potassium, and organic matter contents of the final mother liquor of amino acids prepared by fermentation and the liquid amino acid fertilizer prepared in Example 1 were detected. The above indicators were determined by Kjeldahl method, vanadium molybdenum yellow colorimetric method, flame spectrophotometry, and potassium dichromate method (NYT525-2021), respectively. The detection results of each nutrient content are summarized in Table 1.

[0036] The antibiotic and heavy metal contents of the final mother liquor of amino acids prepared by fermentation and the liquid amino acid fertilizer in Example 1 were detected. Among the above indicators, the antibiotic content was detected by high performance liquid chromatography (GB / T 23385-2009), and the heavy metal content was detected by atomic fluorescence spectrometry and atomic absorption spectrophotometry (NY / T 1978-2022). The effective microorganisms in the liquid amino acid fertilizer prepared in Example 1 were detected by dilution plate count method (NY / T 2321-2013). The test results of each indicator are shown in Table 2.

[0037] The antibacterial effects of three commercially available Bacillus strains and the compound bacterial fermentation agent prepared in Example 1 were tested using the inhibition zone method. The results are shown in Table 3.

[0038] Comparison of the fertilizer effects of liquid amino acid fertilizer: A comparative experiment on the fertilizer effects of amino acid fertilizer was conducted on potted lettuce under natural sunlight and greenhouse conditions. The liquid amino acid fertilizer provided in Example 1 of this invention was used as the experimental group, a commercially available amino acid fertilizer (manufacturer: Wanxian) was used as the control group, and no organic fertilizer was applied as the blank control group. The soil weight of each pot was 500g, the fertility was uniform, and the initial growth of lettuce was the same. The experiment was conducted in 3 replicates. During the experiment, the fertilizer was applied in 3 applications over a period of 30 days, with an interval of 10 days between applications. The commercially available amino acid fertilizer and the liquid amino acid fertilizer in Example 1 of this invention were applied at the same rate, diluted 50 times before use, with each application being 25mL. The blank control group was treated with an equal amount of water and no fertilizer was applied. In this example, the tested soil was yellow clay soil: organic matter content 18.5 g / kg, humic acid content 8.9 g / kg, total nitrogen 0.156%, total phosphorus 0.044%, total potassium 1.48%, available phosphorus content 5.1 mg / kg, available potassium content 96.5 mg / kg, and hydrolyzable nitrogen content 5.6 mg / kg.

[0039] The protein, potassium, calcium, iron, and vitamin C contents in lettuce were tested in the fertilizer effect comparison experiment. The above indicators were determined by Kjeldahl method, flame spectrophotometry, atomic absorption spectrophotometry, o-phenanthroline spectrophotometry, and 2,6-dichlorophenolindophenol titration method, respectively, in accordance with NYT 4076-2022, NYT 525-2021, and GB 5009.86-2016. The test results of each biochemical indicator are shown in Table 4.

[0040] The soil physicochemical indicators in the fertilizer effect comparison experiment were tested. The sampling method was three-point sampling, taking soil samples at a depth of 5cm, air-drying, grinding and passing them through a 2mm sieve. Humic acid was detected by titration (NY / T1971-2010). The detection methods for organic matter, nitrogen, phosphorus and potassium content were the same as those for liquid amino acid fertilizer in Example 1. The results are shown in Table 5.

[0041] The experimental results are as follows:

[0042] The results of testing basic indicators such as antibiotics, heavy metals (based on drying), total nitrogen, hydrolyzable nitrogen, and organic matter in the amino acid final mother liquor before and after fermentation are shown in Tables 1 and 2. The content of nutrients such as hydrolyzable nitrogen, available phosphorus, and available potassium was significantly increased after fermentation, and the number of viable bacteria was significantly higher than the limit standards required for compound microbial fertilizers. The content of antibiotics and heavy metals in the amino acid final mother liquor and liquid amino acid fertilizer was significantly lower than the limit standards required for organic fertilizers. As shown in Table 2, the heavy metal and antibiotic residues in the amino acid final mother liquor used in this invention are extremely low (even undetectable). When used as a raw material for liquid amino acid fertilizer, no additional detoxification or purification pretreatment is required, thereby reducing the complexity of the process and the risk of secondary pollution, and laying a solid foundation for the safety of the final product.

[0043]

[0044]

[0045] The three Bacillus strains and the compound bacterial fermentation agent showed different degrees of antibacterial effect against plant pathogens. The inhibition zone results are shown in Table 3. It can be seen that after the three Bacillus strains were made into a compound bacterial agent, the diameter of its inhibition zone was significantly larger than that of the single strain, and the inhibition effect on pathogens was better.

[0046]

[0047] The effects of different amino acid fertilizers on the growth and physicochemical properties of lettuce are shown in Table 4. Apart from the different fertilizers used, all other growth conditions and management methods were identical across the experimental groups. The liquid amino acid fertilizer produced in Example 1 significantly improved lettuce quality and increased its nutrient content.

[0048]

[0049] The effects of different amino acid fertilizers on soil physicochemical properties are shown in Table 5. Compared with the blank control and commercially available amino acid fertilizers, the amino acid liquid microbial fertilizer provided in Example 1 of this invention can significantly improve the physicochemical properties and structure of the soil. Application of the amino acid liquid microbial fertilizer of this invention significantly increased the contents of total nitrogen, hydrolyzable nitrogen, available phosphorus, available potassium, organic matter, and humic acid in the soil, with increases of 68.6%, 55.3%, 24.1%, 27.5%, 90.7%, and 93.6% respectively compared to the blank control group. This indicates that application of the amino acid liquid microbial fertilizer of this invention can significantly improve fertilizer efficiency and soil fertility.

[0050]

[0051] The fermentation-based amino acid final mother liquor described in this invention refers to the waste liquid generated after the fermentation production of threonine. Using this waste liquid as the main raw material in the liquid component, a small amount of reagents and beneficial microbial agents are added for secondary fermentation to produce bio-based fertilizer. The effective components of the bio-based fertilizer mainly include organic matter, humic acid, protein, peptides, and various vitamins and trace elements. Organic matter functions: provides nutrients, enhances soil water retention, promotes microbial reproduction, and improves crop physiological functions. Humic acid functions: promotes the formation of soil aggregates, increases soil permeability, and improves fertilizer utilization. Protein and peptide functions: directly provides crop nutrients and improves crop resistance. Vitamin and trace element functions: increases crop yield and maintains the nutrients required for crop growth. In addition, the added beneficial microorganisms promote plant growth, inhibit diseases, and improve the soil environment.

[0052] The amino acid liquid bacterial fertilizer prepared by this invention uses the final mother liquor of threonine fermentation as a specific raw material. It contains a variety of complex nutrients, resulting in better fertilizer efficiency and improved growth promotion. The bacterial strains used in this invention also have the effects of promoting growth and inhibiting pathogens. The synergistic effect significantly improves the fertilizer's efficiency and improves the soil environment.

[0053] This invention discloses a liquid amino acid fertilizer and its preparation method. Compared with the prior art, its advantages are as follows: First, this invention transforms the waste threonine final mother liquor from fermentation into a valuable resource, enabling its reuse in fermentation fertilizer production. Combined with microbial agents and other co-fermentation methods, the resulting final product not only provides rich nutrients for crops but also reduces soil hardness, increases soil softness, and increases soil organic matter content. Second, the preparation method of this invention is simple and easy to implement, and can be widely promoted and applied.

[0054] Although preferred embodiments of the present invention have been described, those skilled in the art, upon learning the inventive concept of the present invention, can make other changes and modifications to these embodiments, all of which fall within the scope of the present invention.

[0055] Obviously, those skilled in the art can make various modifications and variations to this invention without departing from its spirit and scope. If such modifications and variations fall within the scope of equivalents of this invention, then this invention also intends to include these modifications and variations.

Claims

1. A method for preparing a liquid amino acid fertilizer, characterized in that, Includes the following steps: Carbon source, calcium agent and pH adjuster were added to the final mother liquor of inactivated threonine to obtain fermentation broth; Bacillus subtilis, Bacillus licheniformis and Bacillus amyloliquefaciens were formulated into a compound microbial fermentation agent; Add a compound microbial fermentation agent to the fermentation broth for fermentation treatment, and then add a cell protectant to obtain liquid amino acid fertilizer.

2. The method for preparing liquid amino acid fertilizer according to claim 1, characterized in that, The carbon source is glucose, and the amount of carbon source added is 100 g / L to 300 g / L based on the volume of the final mother liquor of inactivated threonine; the calcium agent is quicklime, and the amount of quicklime added is 8 g / L to 30 g / L based on the volume of the final mother liquor of inactivated threonine.

3. The method for preparing liquid amino acid fertilizer according to claim 1, characterized in that, The pH adjuster is sodium hydroxide, and the pH value of the fermentation broth is 6.5~7.

5.

4. The method for preparing liquid amino acid fertilizer according to claim 1, characterized in that, The fermentation process was carried out at a temperature of 30℃ to 37℃ for 32 hours to 46 hours.

5. The method for preparing liquid amino acid fertilizer according to claim 1, characterized in that, The amount of compound microbial fermentation agent added is 0.8wt%~3wt% based on the mass of the fermentation broth.

6. The method for preparing liquid amino acid fertilizer according to claim 1, characterized in that, In the compound microbial fermentation agent, the ratio of effective viable bacteria of Bacillus subtilis, Bacillus licheniformis and Bacillus amyloliquefaciens is 1:1:

1.

7. The method for preparing liquid amino acid fertilizer according to claim 1, characterized in that, The inactivation treatment of the final amino acid mother liquor was carried out at 70℃ for 20 to 30 minutes.

8. The method for preparing liquid amino acid fertilizer according to claim 1, characterized in that, The cell protectant includes trehalose and vitamin C.

9. The method for preparing liquid amino acid fertilizer according to claim 8, characterized in that, Based on the mass of the fermentation broth, the amount of trehalose added is 4wt%~6wt%, and the amount of vitamin C added is 0.1wt%~0.3wt%.

10. A liquid amino acid fertilizer, characterized in that, It is prepared by the method described in any one of claims 1 to 9.

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