Multifunctional bactericidal fertilizer containing eucalyptus extract and preparation method thereof

Abstract

The invention relates to the technical field of organic fertilizers, and discloses a eucalyptus extract-containing multifunctional bactericidal fertilizer and a preparation method thereof, and the microcapsule-shaped multifunctional bactericidal fertilizer is prepared by coating an organic fertilizer core material with a coating layer, the coating layer is divided into an inner layer and an outer layer, the inner layer is a slow-release antibacterial layer, and the outer layer is a microbial response layer; the organic fertilizer core material is prepared from the following raw materials in parts by mass: 40 to 60 parts of decomposed organic matter, 10 to 20 parts of urea, 8 to 15 parts of monopotassium phosphate, 5 to 10 parts of diatomite and 10 to 15 parts of deionized water. The problems that a traditional product is low in utilization rate and pollutes the environment are effectively solved, the fertilizer efficiency and the antibacterial time efficiency are prolonged through a slow release structure, the utilization rate of active ingredients is increased by means of a dual response mechanism, a practical solution is provided for green prevention and control of agricultural diseases and efficient fertilization, and remarkable technical advantages and application value are achieved.

Description

Technical Field

[0001] This invention relates to the field of organic fertilizer technology, specifically to a multifunctional bactericidal fertilizer containing eucalyptus extract and its preparation method. Background Technology

[0002] Traditional chemical fertilizers have played a significant role in increasing crop yields, but long-term excessive use can lead to soil compaction, microbial imbalance, agricultural product residues, and environmental pollution. Furthermore, the control of crop diseases relies heavily on chemical pesticides, further exacerbating ecological and environmental pressures and food safety risks. Eucalyptus plants are rich in macrocyclic compounds, antimicrobial peptides, and other active substances. Their extracts have significant inhibitory effects on both Gram-positive and Gram-negative bacteria. However, direct application presents problems such as odor irritation and insufficient stability. The current technological challenge is how to stably and efficiently integrate eucalyptus extracts into fertilizer carriers, enabling slow release into the soil and achieving a multifunctional effect of both fertilizer and pesticide. Therefore, developing a multifunctional fertilizer that provides nutrients and inhibits diseases has significant application value. Summary of the Invention

[0003] (a) Technical problems to be solved To address the shortcomings of existing technologies, this invention provides a multifunctional bactericidal fertilizer containing eucalyptus extract and its preparation method.

[0004] (II) Technical Solution To achieve the above objectives, the present invention provides the following technical solution: In a first aspect, a multifunctional bactericidal fertilizer containing eucalyptus extract is a multifunctional bactericidal fertilizer in the form of microcapsules made by coating an organic fertilizer core material with a coating layer. The coating layer is divided into an inner layer and an outer layer. The inner layer is a slow-release antibacterial layer, and the outer layer is a microbial response layer. The organic fertilizer core material comprises the following raw materials in parts by weight: 40-60 parts of decomposed organic matter, 10-20 parts of urea, 8-15 parts of potassium dihydrogen phosphate, 5-10 parts of diatomaceous earth, and 10-15 parts of deionized water.

[0005] Furthermore, the method for preparing the microbial response layer includes the following steps: Mix 10-15 parts of glycosylated carrier, 2-3 parts of peanut lectin-liposome, and 1-2 parts of thermosensitive drug-loaded liposome in 40-60 parts of phosphate buffer, stir and incubate at room temperature for 1-2 h at a speed of 150-200 r / min to obtain a microbial response layer.

[0006] Furthermore, the preparation method of the glycosylated carrier includes the following steps: Take 10-20 parts of aminated mesoporous silica and disperse it in 50-100 parts of phosphate buffer. Stir at 200-300 r / min for 10-15 min. Then add 2-3 parts of lactobionic acid, 1-1.8 parts of 1-ethyl-(3-dimethylaminopropyl)carbodiimide and 0.6-0.9 parts of N-hydroxysuccinimide. Stir at 300-500 r / min for 4-6 h. After the reaction is complete, centrifuge to collect the product. Wash with phosphate buffer 2-3 times at 8000-10000 r / min for 10-15 min. Dry under vacuum at 40-50℃ and -0.08--0.1 MPa to constant weight to obtain the glycosylated carrier.

[0007] Furthermore, the preparation method of the peanut lectin-liposome includes the following steps: A1. Dissolve 6-8 parts of dipalmitoylphosphatidylcholine, 2-3 parts of cholesterol, 0.8-1.2 parts of distearylphosphatidylethanolamine-polyethylene glycol 2000, and 0.2-0.4 parts of distearylphosphatidylacetamide-polyethylene glycol 2000-biotin in 40-60 parts of chloroform. Place the solution in a rotary evaporator and evaporate at 40-45℃ and -0.07-0.09 MPa for 10-30 min. Add 40-60 parts of phosphate buffer and shake in a water bath at 45-50℃ for 20-30 min at a speed of 200-300 r / min. Then, homogenize the solution in a high-pressure homogenizer at 600-800 bar for 3-5 cycles to obtain biotinylated liposomes. A2. Add 0.3-0.5 parts of streptavidin to biotinylated liposomes, stir and incubate at room temperature for 1-2 h at a speed of 100-150 r / min to prepare avidinized liposomes; A3. Slowly add 0.2 to 0.3 parts of biotinylated peanut lectin to the avidinized liposome system and incubate at room temperature in the dark for 1 to 2 hours. Purify the reaction solution through a gel filtration column and collect the peanut lectin-liposome suspension corresponding to the elution peak.

[0008] Furthermore, the method for preparing the thermosensitive drug-loaded liposomes includes the following steps: Dissolve 7-9 parts dipalmitoylphosphatidylcholine and 3-4 parts cholesterol in 40-60 parts chloroform, place in a rotary evaporator, and rotary evaporate at 40-45℃ and -0.07-0.09 MPa for 10-30 min to obtain a lipid membrane; dissolve 2-5 parts eucalyptus extract in 10-15 parts ethanol, add 30-40 parts deionized water, and stir at 200-300 r / min for 3-5 min to obtain an extract suspension; add the extract suspension to the lipid membrane, hydrate at 45-48℃ for 20-30 min, homogenize in a high-pressure homogenizer at 600-800 bar for 3-5 cycles, centrifuge at 5000-8000 r / min for 5-10 min to obtain thermosensitive drug-loaded liposomes.

[0009] Furthermore, the method for preparing the sustained-release antibacterial layer includes the following steps: Take 10-20 parts of eucalyptus extract, add 1-3 parts of emulsifier and 40-60 parts of deionized water, place in a high-speed shear emulsifier, and shear emulsify for 10-15 min at 30-35℃ and 8000-10000 r / min to obtain a eucalyptus extract emulsion; take 30-50 parts of dipalmitoylphosphatidylcholine, add 40-60 parts of deionized water, stir until completely dissolved at 40-45℃ and 300-500 r / min, slowly add the eucalyptus extract emulsion, stir for 10-30 min at 32-35℃ and 500-600 r / min, adjust the pH to 6.0-6.5 with 0.1 mol / L hydrochloric acid solution to obtain a sustained-release antibacterial layer.

[0010] Furthermore, the preparation method of the organic fertilizer core material includes the following steps: Well-rotted organic matter, urea, potassium dihydrogen phosphate, and diatomaceous earth are added to a mixer and stirred for 10-30 minutes at 25-30℃ and 200-300 r / min. Deionized water is sprayed into the mixture, and the mixture is then transferred to a disc granulator for granulation at 30-40 r / min, controlling the particle size to 2-4 mm. The granulated organic fertilizer particles are placed in a hot air drying oven at 105-110℃ and dried until the moisture content is ≤8%. After cooling to room temperature, the organic fertilizer core material is obtained.

[0011] A second aspect of the present invention provides a method for preparing a multifunctional bactericidal fertilizer containing eucalyptus extract, comprising the following steps: S1. Add the organic fertilizer core material to a fluidized bed coating machine with an inlet air temperature of 55-65℃ and an outlet air temperature of 30-35℃. Turn on the equipment and rotate at 20-30 r / min. Spray the slow-release antibacterial layer evenly onto the surface of the core material using a spray gun at a spray rate of 5-8 mL / min and a coating time of 10-15 min. After coating, dry at 40-45℃ for 5-10 min and adjust the moisture content to 10-12% to obtain the core material-inner layer intermediate. S2. Keeping the fluidized bed equipment parameters unchanged, spray the microbial response layer evenly onto the surface of the core material-inner layer intermediate through a spray gun at a spray rate of 3~5 mL / min and a coating time of 15~20 min. After coating, reduce the fluidized bed inlet air temperature to 40~45℃ and continue drying for 10~15 min. Adjust the moisture content of the finished product to ≤8%. S3. Turn off the equipment, remove the granules with a particle size of 2.5~5 mm, and obtain the finished product of multifunctional bactericidal fertilizer containing eucalyptus extract.

[0012] (iii) Beneficial technical effects This invention provides a multifunctional bactericidal fertilizer containing eucalyptus extract and its preparation method. The inner slow-release antibacterial layer uses natural lipid materials as a carrier, locking in the antibacterial active ingredients through physical encapsulation and interfacial interactions, preventing rapid degradation or loss in the soil, while simultaneously delaying the rapid release of fertilizer nutrients, reducing waste and environmental burden. The outer microbial response layer integrates specific recognition elements and a temperature-sensitive triggering mechanism. Utilizing the specific binding of pathogen surface characteristic molecules with the recognition elements, combined with local temperature changes at the infection site, it precisely triggers the directional release of antibacterial components, ensuring that the active substances are concentrated and effective in the disease-affected area. The slow-release structure prolongs the fertilizer effect and antibacterial duration, while the dual-response mechanism improves the utilization rate of active ingredients, avoiding waste caused by ineffective release. Furthermore, the wall materials and raw materials used are environmentally compatible, naturally degradable in the soil without residual pollution, and the organic fertilizer core material improves soil structure, balancing crop growth needs with soil ecological protection.

[0013] This invention effectively solves the problems of low utilization rate and environmental pollution of traditional products, and requires no special production equipment. It is suitable for large-scale application and provides a practical solution for green prevention and control of agricultural diseases and efficient fertilization. It has significant technical advantages and application value. Detailed Implementation

[0014] The technical solutions of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. 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.

[0015] Unless otherwise specified, all components of the multifunctional bactericidal fertilizer formula of this invention are commercially available. All parts used in this invention are parts by weight; Well-rotted organic matter: ≥85% compostability, C / N ratio 25~30, moisture content ≤15%, organic matter content ≥45%, purchased from Shandong Lvbang Crop Science Co., Ltd. Urea: Nitrogen content ≥46.4%, particle size 0.85~2.80 mm, purchased from Chongqing Hesheng Longgang Technology Co., Ltd.; Diatomaceous earth: particle size 100~200 mesh, purchased from Shengzhou Huali Diatomaceous Earth Products Co., Ltd.; Eucalyptus extract: eucalyptol ≥20%, antimicrobial peptides ≥35%, moisture ≤5%, particle size ≤10 μm, purchased from Guangxi Luyuan Biotechnology Co., Ltd. The emulsifier was polyglycerol fatty acid ester, purchased from Nantong Aokai Biotechnology Co., Ltd. Dipalmitoylphosphatidylcholine and lactobionic acid were purchased from Shanghai Yuanye Biotechnology Co., Ltd. Aminated mesoporous silica: particle size 50~100 nm, amino modification rate ≥80%, purchased from Jiangsu Xianfeng Nanomaterials Technology Co., Ltd. Distearate phosphatidylethanolamine-polyethylene glycol 2000 was purchased from Shanghai Jizhi Biochemical Technology Co., Ltd. Distearate phosphatidyl acetamide-polyethylene glycol 2000-biotin was purchased from Chongqing Yusi Pharmaceutical Technology Co., Ltd. Streptospirin was purchased from Shanghai Sangon Biotech Co., Ltd. Biotinylated peanut lectin was purchased from Beijing Solarbio Technology Co., Ltd. Example

[0016] A multifunctional bactericidal fertilizer containing eucalyptus extract, comprising an organic fertilizer core material coated with a coating layer to form a microcapsule-shaped multifunctional bactericidal fertilizer; The coating layer is divided into an inner layer and an outer layer. The inner layer is a slow-release antibacterial layer, and the outer layer is a microbial response layer. The organic fertilizer core material comprises the following raw materials in parts by weight: 40 parts of decomposed organic matter, 10 parts of urea, 8 parts of potassium dihydrogen phosphate, 5 parts of diatomaceous earth, and 10 parts of deionized water.

[0017] The method for preparing the microbial response layer includes the following steps: Ten parts of glycosylated carrier, two parts of peanut lectin-liposome, and one part of thermosensitive drug-loaded liposome were mixed in 40 parts of phosphate buffer and stirred and incubated at room temperature for 1 h at a speed of 150 r / min to obtain a microbial response layer.

[0018] The preparation method of the glycosylated carrier includes the following steps: Ten parts of aminated mesoporous silica were dispersed in 50 parts of phosphate buffer and stirred at 200 r / min for 10 min. Then, 2 parts of lactobionic acid, 1 part of 1-ethyl-(3-dimethylaminopropyl)carbodiimide and 0.6 parts of N-hydroxysuccinimide were added sequentially and stirred at 300 r / min for 4 h. After the reaction was completed, the product was collected by centrifugation and washed twice with phosphate buffer at 8000 r / min for 10 min. The product was then dried under vacuum at 40 °C and -0.08 MPa to constant weight to obtain the glycosylated carrier.

[0019] The method for preparing the peanut lectin-liposome includes the following steps: A1. Dissolve 6 parts of dipalmitoylphosphatidylcholine, 2 parts of cholesterol, 0.8 parts of distearylphosphatidylethanolamine-polyethylene glycol 2000, and 0.2 parts of distearylphosphatidylacetamide-polyethylene glycol 2000-biotin in 40 parts of chloroform. Place the solution in a rotary evaporator and evaporate at 40°C and -0.07 MPa for 10 min. Add 40 parts of phosphate buffer and shake in a water bath at 45°C for 20 min at a speed of 200 r / min. Then, homogenize the solution three times using a high-pressure homogenizer at 600 bar to obtain biotinylated liposomes. A2. Add 0.3 parts of streptavidin to biotinylated liposomes, stir and incubate at room temperature for 1 h at 100 r / min to prepare avidinized liposomes; A3. Slowly add 0.2 parts of biotinylated peanut lectin to the avidinized liposome system and incubate at room temperature in the dark for 1 h. Purify the reaction solution through a gel filtration column and collect the peanut lectin-liposome suspension corresponding to the elution peak.

[0020] The method for preparing the thermosensitive drug-loaded liposomes includes the following steps: Seven parts of dipalmitoylphosphatidylcholine and three parts of cholesterol were dissolved in 40 parts of chloroform and placed in a rotary evaporator. The mixture was evaporated at 40°C and -0.07 MPa for 10 min to obtain a lipid membrane. Two parts of eucalyptus extract were dissolved in 10 parts of ethanol and then 30 parts of deionized water were added. The mixture was stirred at 200 r / min for 3 min to obtain an extract suspension. The extract suspension was added to the lipid membrane and hydrated at 45°C for 20 min. The mixture was homogenized three times at 600 bar using a high-pressure homogenizer and then centrifuged at 5000 r / min for 5 min to obtain thermosensitive drug-loaded liposomes.

[0021] The method for preparing the sustained-release antibacterial layer includes the following steps: Take 10 parts of eucalyptus extract, add 1 part of emulsifier and 40 parts of deionized water, place in a high-speed shear emulsifier, and shear emulsify for 10 min at 30℃ and 8000 r / min to obtain eucalyptus extract emulsion; take 30 parts of dipalmitoylphosphatidylcholine, add 40 parts of deionized water, stir at 40℃ and 300 r / min until completely dissolved, slowly add to eucalyptus extract emulsion, stir at 32℃ and 500 r / min for 10 min, adjust pH to 6.0 with 0.1 mol / L hydrochloric acid solution to obtain sustained-release antibacterial layer.

[0022] The preparation method of the organic fertilizer core material includes the following steps: Well-rotted organic matter, urea, potassium dihydrogen phosphate, and diatomaceous earth are added to a mixer and mixed at 25°C and 200 r / min for 10 min. Deionized water is sprayed into the mixture, and the mixture is transferred to a disc granulator for granulation at 30 r / min with a particle size of 2 mm. The granulated organic fertilizer particles are placed in a 105°C hot air drying oven and dried until the moisture content is ≤8%. After cooling to room temperature, organic fertilizer core material is obtained.

[0023] A method for preparing a multifunctional bactericidal fertilizer containing eucalyptus extract includes the following steps: S1. Add the organic fertilizer core material to the fluidized bed coating machine. The inlet air temperature is 55℃ and the outlet air temperature is 30℃. Turn on the equipment and rotate at 20 r / min. Spray the slow-release antibacterial layer evenly onto the surface of the core material through a spray gun at a spray rate of 5 mL / min and a coating time of 10 min. After coating, dry at 40℃ for 5 min and adjust the moisture content to 10% to obtain the core material-inner layer intermediate. S2. Keeping the fluidized bed equipment parameters unchanged, the microbial response layer is evenly sprayed onto the surface of the core material-inner layer intermediate through a spray gun at a spray rate of 3 mL / min and a coating time of 15 min. After coating, the fluidized bed inlet air temperature is reduced to 40℃, and drying is continued for 10 min. The moisture content of the finished product is adjusted to ≤8%. S3. Turn off the equipment, remove the granules, the particle size is 2.5 mm, and obtain the finished product of multifunctional bactericidal fertilizer containing eucalyptus extract. Example

[0024] A multifunctional bactericidal fertilizer containing eucalyptus extract, comprising an organic fertilizer core material coated with a coating layer to form a microcapsule-shaped multifunctional bactericidal fertilizer; The coating layer is divided into an inner layer and an outer layer. The inner layer is a slow-release antibacterial layer, and the outer layer is a microbial response layer. The organic fertilizer core material comprises the following raw materials in parts by weight: 50 parts of decomposed organic matter, 15 parts of urea, 10 parts of potassium dihydrogen phosphate, 8 parts of diatomaceous earth, and 12 parts of deionized water.

[0025] The method for preparing the microbial response layer includes the following steps: 12 parts of glycosylated carrier, 2.5 parts of peanut lectin-liposome, and 1.5 parts of thermosensitive drug-loaded liposome were mixed in 50 parts of phosphate buffer and stirred at room temperature for 1.5 h at a speed of 180 r / min to obtain a microbial response layer.

[0026] The preparation method of the glycosylated carrier includes the following steps: 15 parts of aminated mesoporous silica were dispersed in 80 parts of phosphate buffer and stirred at 250 r / min for 10 min. Then, 2.5 parts of lactobionic acid, 1.5 parts of 1-ethyl-(3-dimethylaminopropyl)carbodiimide and 0.8 parts of N-hydroxysuccinimide were added sequentially and stirred at 400 r / min for 5 h. After the reaction was completed, the product was collected by centrifugation and washed twice with phosphate buffer at 9000 r / min for 10 min. The product was then dried under vacuum at 45 °C and -0.09 MPa to constant weight to obtain the glycosylated carrier.

[0027] The method for preparing the peanut lectin-liposome includes the following steps: A1. Dissolve 7 parts of dipalmitoylphosphatidylcholine, 2.5 parts of cholesterol, 1 part of distearylphosphatidylethanolamine-polyethylene glycol 2000, and 0.3 parts of distearylphosphatidylacetamide-polyethylene glycol 2000-biotin in 50 parts of chloroform. Place the solution in a rotary evaporator and evaporate at 40°C and -0.08 MPa for 20 min. Add 50 parts of phosphate buffer and shake in a water bath at 45°C for 25 min at a speed of 250 r / min. Then, homogenize the solution in a high-pressure homogenizer at 700 bar for 4 cycles to obtain biotinylated liposomes. A2. Add 0.4 parts of streptavidin to biotinylated liposomes, stir and incubate at room temperature for 1.5 h at 120 r / min to prepare avidinized liposomes; A3. Slowly add 0.25 parts of biotinylated peanut lectin to the avidinized liposome system and incubate at room temperature in the dark for 1.5 h. Purify the reaction solution through a gel filtration column and collect the peanut lectin-liposome suspension corresponding to the elution peak.

[0028] The method for preparing the thermosensitive drug-loaded liposomes includes the following steps: Eight parts of dipalmitoylphosphatidylcholine and three parts of cholesterol were dissolved in 50 parts of chloroform and placed in a rotary evaporator. The mixture was evaporated at 40°C and -0.09 MPa for 20 min to obtain a lipid membrane. Three parts of eucalyptus extract were dissolved in 12 parts of ethanol and then 35 parts of deionized water were added. The mixture was stirred at 250 r / min for 4 min to obtain an extract suspension. The extract suspension was added to the lipid membrane and hydrated at 46°C for 25 min. The mixture was homogenized in a high-pressure homogenizer at 700 bar for 4 cycles and then centrifuged at 6000 r / min for 10 min to obtain thermosensitive drug-loaded liposomes.

[0029] The method for preparing the sustained-release antibacterial layer includes the following steps: Take 15 parts of eucalyptus extract, add 2 parts of emulsifier and 50 parts of deionized water, place in a high-speed shear emulsifier, and shear emulsify for 15 min at 32℃ and 9000 r / min to obtain a eucalyptus extract emulsion; take 40 parts of dipalmitoylphosphatidylcholine, add 50 parts of deionized water, stir at 40℃ and 400 r / min until completely dissolved, slowly add to the eucalyptus extract emulsion, stir at 35℃ and 600 r / min for 20 min, adjust the pH to 6.2 with 0.1 mol / L hydrochloric acid solution to obtain a sustained-release antibacterial layer.

[0030] The preparation method of the organic fertilizer core material includes the following steps: Well-rotted organic matter, urea, potassium dihydrogen phosphate, and diatomaceous earth are added to a mixer and mixed at 25°C and 300 r / min for 20 min. Deionized water is sprayed into the mixture, and the mixture is transferred to a disc granulator for granulation at 40 r / min with a particle size of 3 mm. The granulated organic fertilizer particles are placed in a 105°C hot air drying oven and dried until the moisture content is ≤8%. After cooling to room temperature, the organic fertilizer core material is obtained.

[0031] A method for preparing a multifunctional bactericidal fertilizer containing eucalyptus extract includes the following steps: S1. Add the organic fertilizer core material to the fluidized bed coating machine. The inlet air temperature is 60℃ and the outlet air temperature is 30℃. Turn on the equipment and rotate at 25 r / min. Spray the slow-release antibacterial layer evenly onto the surface of the core material through a spray gun at a spray rate of 6 mL / min and a coating time of 10 min. After coating, dry at 42℃ for 6 min and adjust the moisture content to 11% to obtain the core material-inner layer intermediate. S2. Keeping the fluidized bed equipment parameters unchanged, the microbial response layer is evenly sprayed onto the surface of the core material-inner layer intermediate through a spray gun at a spray rate of 4 mL / min and a coating time of 20 min. After coating, the fluidized bed inlet air temperature is reduced to 45℃, and drying is continued for 15 min. The moisture content of the finished product is adjusted to ≤8%. S3. Turn off the equipment, remove the granules, the particle size is 4 mm, and you will get a multifunctional bactericidal fertilizer product containing eucalyptus extract. Example

[0032] A multifunctional bactericidal fertilizer containing eucalyptus extract, comprising an organic fertilizer core material coated with a coating layer to form a microcapsule-shaped multifunctional bactericidal fertilizer; The coating layer is divided into an inner layer and an outer layer. The inner layer is a slow-release antibacterial layer, and the outer layer is a microbial response layer. The organic fertilizer core material comprises the following raw materials in parts by weight: 60 parts of decomposed organic matter, 20 parts of urea, 15 parts of potassium dihydrogen phosphate, 10 parts of diatomaceous earth, and 15 parts of deionized water.

[0033] The method for preparing the microbial response layer includes the following steps: 15 parts of glycosylated carrier, 3 parts of peanut lectin-liposome, and 2 parts of thermosensitive drug-loaded liposome were mixed in 60 parts of phosphate buffer and stirred and incubated at room temperature for 2 h at 200 r / min to obtain a microbial response layer.

[0034] The preparation method of the glycosylated carrier includes the following steps: 20 parts of aminated mesoporous silica were dispersed in 100 parts of phosphate buffer and stirred at 300 r / min for 15 min. Then, 3 parts of lactobionic acid, 1.8 parts of 1-ethyl-(3-dimethylaminopropyl)carbodiimide and 0.9 parts of N-hydroxysuccinimide were added sequentially and stirred at 500 r / min for 6 h. After the reaction was completed, the product was collected by centrifugation, and washed three times with phosphate buffer at 10000 r / min for 15 min. The product was then dried at 50 °C and -0.1 MPa under vacuum to constant weight to obtain the glycosylated carrier.

[0035] The method for preparing the peanut lectin-liposome includes the following steps: A1. Dissolve 8 parts of dipalmitoylphosphatidylcholine, 3 parts of cholesterol, 1.2 parts of distearylphosphatidylethanolamine-polyethylene glycol 2000, and 0.4 parts of distearylphosphatidylacetamide-polyethylene glycol 2000-biotin in 60 parts of chloroform. Place the solution in a rotary evaporator and evaporate at 45°C and -0.09 MPa for 30 min. Add 60 parts of phosphate buffer and shake in a water bath at 50°C for 30 min at a speed of 300 r / min. Homogenize the solution five times at 800 bar using a high-pressure homogenizer to obtain biotinylated liposomes. A2. Add 0.5 parts of streptavidin to biotinylated liposomes, stir and incubate at room temperature for 2 h at 150 r / min to prepare avidinized liposomes; A3. Slowly add 0.3 parts of biotinylated peanut lectin to the avidinized liposome system and incubate at room temperature in the dark for 2 h. Purify the reaction solution through a gel filtration column and collect the peanut lectin-liposome suspension corresponding to the elution peak.

[0036] The method for preparing the thermosensitive drug-loaded liposomes includes the following steps: Nine parts of dipalmitoylphosphatidylcholine and four parts of cholesterol were dissolved in 60 parts of chloroform and placed in a rotary evaporator. The mixture was evaporated at 45°C and -0.09 MPa for 30 min to obtain a lipid membrane. Five parts of eucalyptus extract were dissolved in 15 parts of ethanol and then 40 parts of deionized water were added. The mixture was stirred at 300 r / min for 5 min to obtain an extract suspension. The extract suspension was added to the lipid membrane and hydrated at 48°C for 30 min. The mixture was homogenized in a high-pressure homogenizer at 800 bar for 5 cycles, centrifuged at 8000 r / min for 10 min to obtain thermosensitive drug-loaded liposomes.

[0037] The method for preparing the sustained-release antibacterial layer includes the following steps: Take 20 parts of eucalyptus extract, add 3 parts of emulsifier and 60 parts of deionized water, place in a high-speed shear emulsifier, and shear emulsify for 15 min at 35℃ and 10000 r / min to obtain a eucalyptus extract emulsion; take 50 parts of dipalmitoylphosphatidylcholine, add 60 parts of deionized water, stir at 45℃ and 500 r / min until completely dissolved, slowly add to the eucalyptus extract emulsion, stir at 35℃ and 600 r / min for 30 min, adjust the pH to 6.5 with 0.1 mol / L hydrochloric acid solution to obtain a sustained-release antibacterial layer.

[0038] The preparation method of the organic fertilizer core material includes the following steps: Well-rotted organic matter, urea, potassium dihydrogen phosphate, and diatomaceous earth are added to a mixer and mixed at 30°C and 300 r / min for 30 min. Deionized water is sprayed into the mixture, and the mixture is transferred to a disc granulator for granulation at 40 r / min with a particle size of 4 mm. The granulated organic fertilizer particles are placed in a 110°C hot air drying oven and dried until the moisture content is ≤8%. After cooling to room temperature, the organic fertilizer core material is obtained.

[0039] A method for preparing a multifunctional bactericidal fertilizer containing eucalyptus extract includes the following steps: S1. Add the organic fertilizer core material to the fluidized bed coating machine. The inlet air temperature is 65℃ and the outlet air temperature is 35℃. Turn on the equipment and rotate at 30 r / min. Spray the slow-release antibacterial layer evenly onto the surface of the core material through a spray gun at a spray rate of 8 mL / min and a coating time of 15 min. After coating, dry at 45℃ for 10 min and adjust the moisture content to 12% to obtain the core material-inner layer intermediate. S2. Keeping the fluidized bed equipment parameters unchanged, the microbial response layer is evenly sprayed onto the surface of the core material-inner layer intermediate through a spray gun at a spray rate of 5 mL / min and a coating time of 20 min. After coating, the fluidized bed inlet air temperature is reduced to 45℃, and drying is continued for 15 min. The moisture content of the finished product is adjusted to ≤8%. S3. Turn off the equipment, remove the granules, the particle size is 5 mm, and you will get a multifunctional bactericidal fertilizer product containing eucalyptus extract.

[0040] Comparative Example 1: Using the organic fertilizer of Example 1, 10 parts of eucalyptus extract were directly and physically mixed with the organic fertilizer raw materials before granulation, without any coating treatment.

[0041] Comparative Example 2: No outer microbial response layer was applied; the remaining components and processes were the same as in Example 1.

[0042] Comparative Example 3: The organic fertilizer used in Example 1 was employed.

[0043] Performance testing: 1. Nutrient release characteristic test Methods: Following the national standard for slow-release fertilizers (GB / T 23348-2009), the static water extraction method was adopted. Samples with equal nitrogen content were placed in water at 25℃, and the cumulative dissolution rates of nitrogen, phosphorus, and potassium in the water were periodically measured to plot nutrient release curves.

[0044] Assessment: Initial dissolution rate (day 1), cumulative release period (time required for the release rate to reach 80%).

[0045] 2. Antibacterial component release and response performance test method: Basic sustained release: Samples were taken periodically in sterile PBS buffer at 25°C, and the cumulative release rate of eucalyptus extract markers (such as 1,8-cineole) was determined by high performance liquid chromatography.

[0046] Temperature-sensitive triggering: After equilibration in PBS at 25°C, the sample was quickly transferred to a water bath at 42°C, and the change in the release rate of the marker was monitored over the next 2 hours.

[0047] Microbial response: In PBS at 25°C, add inactivated target pathogen cells (such as Ralstonia solanacearum) (10 μL). 8The study simulated competition for surface glycosyl groups in pathogens (CFU / mL), monitored changes in the release rate of the marker over the following 4 hours, and compared the results with a sterile control group.

[0048] Assessment: 7-day basal release rate, temperature-sensitive trigger release enhancement factor, and microbial response release enhancement factor.

[0049] Table 1. Nutrient Release Characteristic Test Results Group Initial dissolution rate / % Nutrient accumulation and release period / day Example 1 15.8 55 Example 2 13.5 52 Example 3 14.9 55 Comparative Example 1 >60 <15 Comparative Example 2 18.5 48 Comparative Example 3 >60 <15 Table 2 Results of Antibacterial Component Release and Response Performance Tests Group 7-day basal release rate / % Temperature-sensitive trigger release enhancement factor Microbial response release enhancement factor Example 1 22.5 3.8 2.2 Example 2 18.5 4.0 2.3 Example 3 20.5 4.2 2.5 Comparative Example 1 >80 - - Comparative Example 2 25 3.5 - Comparative Example 3 - - - As shown in Table 1, the initial dissolution rate of the multifunctional bactericidal fertilizers in Examples 1-3 was less than 16%, and the cumulative nutrient release period reached 52-55 days, significantly better than Comparative Examples 1 and 3. Comparative Examples 1 and 3 both had initial dissolution rates exceeding 60% and cumulative release periods of less than 15 days, indicating that uncoated fertilizers are prone to nutrient loss. Comparative Example 2 had an initial dissolution rate of 18.5% and a cumulative release period of 48 days, indicating that the outer microbial response layer not only possesses targeted recognition capabilities but also further enhances the slow-release effect of nutrients.

[0050] As shown in Table 2, the 7-day basal release rate of Examples 1-3 was 18.5-22.5%, which was much lower than that of Comparative Example 1, indicating that the coating structure can effectively inhibit the ineffective release of eucalyptus extract and prolong the action period. Thermosensitive triggering release enhancement factor reached 3.8-4.2 times, and microbial response release enhancement factor was 2.2-2.5 times, while Comparative Example 2 had no microbial response layer and lacked microbial targeting.

[0051] 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 multifunctional bactericidal fertilizer containing eucalyptus extract, characterized in that, A multifunctional bactericidal fertilizer in the form of microcapsules made by coating organic fertilizer core material with a coating layer; The coating layer is divided into an inner layer and an outer layer. The inner layer is a slow-release antibacterial layer, and the outer layer is a microbial response layer. The organic fertilizer core material comprises the following raw materials in parts by weight: 40-60 parts of decomposed organic matter, 10-20 parts of urea, 8-15 parts of potassium dihydrogen phosphate, 5-10 parts of diatomaceous earth, and 10-15 parts of deionized water.

2. The multifunctional bactericidal fertilizer containing eucalyptus extract according to claim 1, characterized in that, The method for preparing the microbial response layer includes the following steps: Mix 10-15 parts of glycosylated carrier, 2-3 parts of peanut lectin-liposome, and 1-2 parts of thermosensitive drug-loaded liposome in 40-60 parts of phosphate buffer, stir and incubate at room temperature for 1-2 h at a speed of 150-200 r / min to obtain a microbial response layer.

3. The multifunctional bactericidal fertilizer containing eucalyptus extract according to claim 2, characterized in that, The preparation method of the glycosylated carrier includes the following steps: Take 10-20 parts of aminated mesoporous silica and disperse it in 50-100 parts of phosphate buffer. Stir at 200-300 r / min for 10-15 min. Then add 2-3 parts of lactobionic acid, 1-1.8 parts of 1-ethyl-(3-dimethylaminopropyl)carbodiimide and 0.6-0.9 parts of N-hydroxysuccinimide. Stir at 300-500 r / min for 4-6 h. After the reaction is complete, centrifuge to collect the product. Wash with phosphate buffer 2-3 times at 8000-10000 r / min for 10-15 min. Dry under vacuum at 40-50℃ and -0.08--0.1 MPa to constant weight to obtain the glycosylated carrier.

4. The multifunctional bactericidal fertilizer containing eucalyptus extract according to claim 2, characterized in that, The method for preparing the peanut lectin-liposome includes the following steps: A1. Dissolve 6-8 parts of dipalmitoylphosphatidylcholine, 2-3 parts of cholesterol, 0.8-1.2 parts of distearylphosphatidylethanolamine-polyethylene glycol 2000, and 0.2-0.4 parts of distearylphosphatidylacetamide-polyethylene glycol 2000-biotin in 40-60 parts of chloroform. Place the solution in a rotary evaporator and evaporate at 40-45℃ and -0.07--0.09 MPa for 10-30 min. Add 40-60 parts of phosphate buffer and shake in a water bath at 45-50℃ for 20-30 min at a speed of 200-300 r / min. Then, homogenize the solution in a high-pressure homogenizer at 600-800 bar for 3-5 cycles to obtain biotinylated liposomes. A2. Add 0.3-0.5 parts of streptavidin to biotinylated liposomes, stir and incubate at room temperature for 1-2 h at a speed of 100-150 r / min to prepare avidinized liposomes; A3. Slowly add 0.2 to 0.3 parts of biotinylated peanut lectin to the avidinized liposome system and incubate at room temperature in the dark for 1 to 2 hours. Purify the reaction solution through a gel filtration column and collect the peanut lectin-liposome suspension corresponding to the elution peak.

5. A multifunctional bactericidal fertilizer containing eucalyptus extract according to claim 2, characterized in that, The method for preparing the thermosensitive drug-loaded liposomes includes the following steps: Dissolve 7-9 parts dipalmitoylphosphatidylcholine and 3-4 parts cholesterol in 40-60 parts chloroform, place in a rotary evaporator, and rotary evaporate at 40-45℃ and -0.07-0.09 MPa for 10-30 min to obtain a lipid membrane; dissolve 2-5 parts eucalyptus extract in 10-15 parts ethanol, add 30-40 parts deionized water, and stir at 200-300 r / min for 3-5 min to obtain an extract suspension; add the extract suspension to the lipid membrane, hydrate at 45-48℃ for 20-30 min, homogenize in a high-pressure homogenizer at 600-800 bar for 3-5 cycles, centrifuge at 5000-8000 r / min for 5-10 min to obtain thermosensitive drug-loaded liposomes.

6. The multifunctional bactericidal fertilizer containing eucalyptus extract according to claim 1, characterized in that, The method for preparing the sustained-release antibacterial layer includes the following steps: Take 10-20 parts of eucalyptus extract, add 1-3 parts of emulsifier and 40-60 parts of deionized water, place in a high-speed shear emulsifier, and shear emulsify for 10-15 min at 30-35℃ and 8000-10000 r / min to obtain a eucalyptus extract emulsion; take 30-50 parts of dipalmitoylphosphatidylcholine, add 40-60 parts of deionized water, stir until completely dissolved at 40-45℃ and 300-500 r / min, slowly add the eucalyptus extract emulsion, stir for 10-30 min at 32-35℃ and 500-600 r / min, adjust the pH to 6.0-6.5 with 0.1 mol / L hydrochloric acid solution to obtain a sustained-release antibacterial layer.

7. The multifunctional bactericidal fertilizer containing eucalyptus extract according to claim 1, characterized in that, The preparation method of the organic fertilizer core material includes the following steps: Well-rotted organic matter, urea, potassium dihydrogen phosphate, and diatomaceous earth are added to a mixer and mixed at 25-30℃ and 200-300 r / min for 10-30 minutes. Deionized water is sprayed into the mixture, and the mixture is transferred to a disc granulator for granulation at 30-40 r / min, controlling the particle size to 2-4 mm. The granulated organic fertilizer particles are placed in a hot air drying oven at 105-110℃ and dried until the moisture content is ≤8%. After cooling to room temperature, the organic fertilizer core material is obtained.

8. A method for preparing a multifunctional bactericidal fertilizer containing eucalyptus extract according to any one of claims 1 to 7, characterized in that, Includes the following steps: S1. Add the organic fertilizer core material to a fluidized bed coating machine with an inlet air temperature of 55-65℃ and an outlet air temperature of 30-35℃. Turn on the equipment and rotate at 20-30 r / min. Spray the slow-release antibacterial layer evenly onto the surface of the core material using a spray gun at a spray rate of 5-8 mL / min. Coating time is 10-15 min. After coating, dry at 40-45℃ for 5-10 min and adjust the moisture content to 10-12% to obtain the core material-inner layer intermediate. S2. Keeping the fluidized bed equipment parameters unchanged, spray the microbial response layer evenly onto the surface of the core material-inner layer intermediate through a spray gun at a spray rate of 3~5 mL / min and a coating time of 15~20 min. After coating, reduce the fluidized bed inlet air temperature to 40~45℃ and continue drying for 10~15 min. Adjust the moisture content of the finished product to ≤8%. S3. Turn off the equipment, remove the granules with a particle size of 2.5~5 mm, and obtain the finished product of multifunctional bactericidal fertilizer containing eucalyptus extract.