Microcapsules and methods of making, and prepared feed and methods of producing feed

Abstract

The present application relates to the technical field of livestock breeding, and provides a microcapsule and a preparation method thereof, prepared feed and a feed production method, wherein the microcapsule comprises a mixture of bacteria and enzymes, a sealing isolation layer, a pH response layer and a lipid outer layer; the mixture of bacteria and enzymes is arranged as a core, the sealing isolation layer is wrapped on the outer circumferential side of the mixture of bacteria and enzymes, the pH response layer is wrapped on the outer circumferential side of the sealing isolation layer, and the lipid outer layer is wrapped on the outer circumferential side of the pH response layer; wherein the mixture of bacteria and enzymes comprises an SOD composite enzyme containing Mn3O4 nanoparticles and a probiotic preparation. Through manganese enrichment domestication and multi-layer embedding technology, the gastric acid tolerance of the microcapsule is improved. The mixture of bacteria and enzymes made of the SOD composite enzyme containing Mn3O4 nanoparticles and the probiotic preparation can achieve the functions of bacteriostasis, oxidation resistance, growth promotion, deodorization and improvement of meat quality, which are the properties of the SOD composite enzyme itself, and can also simultaneously improve the muscle proportion of livestock and poultry and meat quality, thus improving the comprehensive benefits of livestock and poultry breeding.

Description

Technical Field

[0001] This invention relates to the field of animal husbandry technology, specifically to a microcapsule and its preparation method, as well as the prepared feed and feed production method. Background Technology

[0002] In livestock farming, the application of feed additives has a significant impact on the growth performance of livestock and poultry. For a long time, the livestock industry has widely relied on antibiotics as feed additives to promote livestock and poultry growth. However, this practice has led to serious problems of increased antibiotic resistance in pathogens and excessive drug residues in livestock products, posing a potential threat to food safety and public health. Therefore, a comprehensive "antibiotic ban" policy has been implemented in the feed industry to address the series of problems caused by antibiotic abuse.

[0003] In response to the "antibiotic ban" policy, the industry has tried to use traditional feed additives to replace antibiotics. However, the application of these additives has caused new problems, such as the accumulation of heavy metals and environmental pollution during the breeding process, making it difficult to meet the requirements of sustainable breeding.

[0004] Another proposal suggests using microbial additives to replace antibiotics, but existing microbial additives have drawbacks such as limited functionality and poor tolerance to gastric acid. Furthermore, in aquaculture practice, undigested protein in feed is fermented by intestinal microorganisms, producing large amounts of malodorous gases such as hydrogen sulfide (H2S) and ammonia (NH3), leading to the accumulation of odorous substances in feces. This is accompanied by excessive nitrogen and phosphorus emissions, which can easily cause eutrophication of water bodies and have a negative impact on the aquaculture environment.

[0005] In addition, although some commercial probiotics (such as Enterococcus faecalis) have been used to replace antibiotics and can improve the digestibility of livestock and poultry to a certain extent, they still have obvious limitations: their functions are relatively simple and they cannot achieve multiple functions such as anti-oxidation and deodorization; moreover, they have poor tolerance to gastric acid and low survival rate in livestock and poultry, resulting in unstable application effects and difficulty in meeting the actual needs of breeding production.

[0006] Meanwhile, after the ban on antibiotics, the growth of livestock and poultry muscle is easily inhibited, accompanied by fat accumulation (such as increased abdominal fat percentage in broilers and a deterioration in feed conversion ratio); in addition, under the intensive farming model, the drip loss of meat is high and the flavor substances are reduced, which further reduces the quality of meat.

[0007] In summary, under the "antibiotic ban" background, existing feed additive alternatives all have their own shortcomings. There is an urgent need to develop a feed additive that can simultaneously achieve antibacterial, antioxidant, growth-promoting, deodorizing, and meat quality-improving effects, while also possessing good stomach acid tolerance and environmental friendliness, in order to solve the aforementioned technical problems faced in the livestock farming sector. Summary of the Invention

[0008] In view of the above-mentioned shortcomings of the prior art, the present invention provides a microcapsule, a preparation method thereof, a feed prepared therefrom, and a feed production method thereof.

[0009] To achieve the above objectives, the present invention provides the following technical solution:

[0010] In a first aspect, a microcapsule is provided, comprising: a bacterial enzyme mixture, a sealing and isolation layer, a pH-responsive layer, and a lipid outer layer;

[0011] The bacterial enzyme mixture is set as the core, the sealing isolation layer covers the outer periphery of the bacterial enzyme mixture, the pH-responsive layer covers the outer periphery of the sealing isolation layer, and the lipid outer layer covers the outer periphery of the pH-responsive layer. The bacterial enzyme mixture includes SOD complex enzyme containing Mn3O4 nanoparticles and probiotic preparation.

[0012] In some embodiments, the sealing and isolation layer is a film layer formed by sequentially spraying sodium alginate solution and CaCl2 solution.

[0013] In some embodiments, the pH-responsive layer is configured as a sodium alginate-chitosan composite gel, and the lipid outer layer is configured as hydrogenated palm oil.

[0014] Secondly, a method for preparing microcapsules is provided, comprising the following steps:

[0015] The sealing and isolation layer is coated on the outside of the bacterial enzyme mixture using an encapsulation machine;

[0016] The pH-responsive layer is encapsulated on the outside of the sealing and isolation layer using an embedding machine;

[0017] The lipid outer layer is then encapsulated on the outside of the pH-responsive layer using an encapsulation machine and cured at low temperature to obtain microcapsules.

[0018] In some embodiments, the step of further encapsulating the outer lipid layer of the pH-responsive layer using an encapsulation machine and then curing it at low temperature to obtain microcapsules further includes:

[0019] The curing parameters are: 4℃ cold air setting for 10 minutes.

[0020] Thirdly, a feed is provided, comprising, by weight parts: 100 parts of basal feed and 0.2 to 0.4 parts of microcapsules.

[0021] Fourthly, a feed production method is provided, comprising the following steps:

[0022] Using SOD complex enzyme and probiotic preparation as the core, microcapsules are sequentially coated with a sealing and isolation layer, a pH-responsive layer and a lipid outer layer to obtain microcapsules.

[0023] The microcapsules were added to the basic feed for feeding.

[0024] The effects were validated through metagenomics, and the functional genes of the strain were analyzed and regulated.

[0025] In some embodiments, the SOD complex enzyme is prepared by the following steps:

[0026] The raw material of purple okra is crushed and extracted to obtain purple okra extract, ensuring that the content of polysaccharides in the purple okra extract reaches more than 18% and the content of flavonoids reaches more than 2.5%.

[0027] A composite culture medium consisting of 40% okra extract, 30% soybean meal, and 30% Mn3O4 nanoparticles was inoculated with Bacillus amyloliquefaciens.

[0028] The composite culture medium inoculated with the aforementioned Bacillus amyloliquefaciens was subjected to a three-stage fermentation process: aerobic fermentation: fermentation at 35°C for 24 h, oxygen-limited induction: induction at 28°C for 48 h, and low-temperature enzyme production: production at 15°C for 12 h, to obtain SOD complex enzyme. The SOD complex enzyme has an enzyme activity ≥8000 U / g and contains Mn-SOD and CuZn-SOD.

[0029] In some embodiments, in the step of pulverizing and extracting the okra raw material to obtain okra extract, ensuring that the okra extract contains at least 18% polysaccharides and at least 2.5% flavonoids:

[0030] The material is pulverized using ultra-fine grinding technology to a particle size corresponding to a sieve mesh size of 2500 mesh.

[0031] In some embodiments, in the step of pulverizing and extracting the okra raw material to obtain okra extract, ensuring that the okra extract contains at least 18% polysaccharides and at least 2.5% flavonoids:

[0032] The parameters for the low-temperature extraction are: temperature 50℃, pH=6.0.

[0033] Compared with existing technologies, the beneficial effects of this invention are as follows: During use, the microcapsules of this application, through a multi-layer encapsulation design, encapsulate the bacterial enzyme mixture within a core, thereby replacing antibiotics in feed and overcoming the problems of escalating pathogen resistance and drug residues. Furthermore, the multi-layered structure is environmentally friendly and pollution-free, avoiding the heavy metal accumulation and environmental pollution problems that may be caused by traditional feed additives, exhibiting significant safety and environmental advantages. In addition, the manganese-enriched acclimatization and multi-layer encapsulation technology also enhance the microcapsules' stomach acid tolerance. Therefore, when used, the microcapsules of this application can smoothly travel from the poultry's stomach to the intestines, and through tolerance to the intestinal environment and synergistic metabolism, ultimately promote nutrient absorption and improve intestinal health. Moreover, the bacterial enzyme mixture, made from SOD complex enzymes containing Mn3O4 nanoparticles and probiotic preparations, can achieve functions such as antibacterial, antioxidant, growth-promoting, deodorizing, and meat quality improvement. These are inherent properties of the SOD complex enzyme itself, and can also simultaneously improve the muscle ratio and meat quality of livestock and poultry, thus improving the overall benefits of livestock and poultry farming. Attached Figure Description

[0034] Figure 1 This is a schematic diagram of the three-dimensional structure of the microcapsule of the present invention;

[0035] Figure 2 This is a schematic flowchart of the microcapsule preparation method of the present invention;

[0036] Figure 3 This is a schematic diagram of the feed production method of the present invention.

[0037] 10. Microcapsule; 100. Bacterial enzyme mixture; 200. Sealing and isolation layer; 300. pH-responsive layer; 400. Lipid outer layer. Detailed Implementation

[0038] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. The described embodiments are some, but not all, of the embodiments of the present invention.

[0039] Therefore, the following detailed description of the embodiments of the invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but merely to illustrate selected embodiments of the invention. All other embodiments obtained by those skilled in the art based on the embodiments of the invention without inventive effort are within the scope of protection of the invention.

[0040] like Figure 1As shown, a microcapsule 10 is provided, comprising: a bacterial enzyme mixture 100, a sealing isolation layer 200, a pH-responsive layer 300, and a lipid outer layer 400; the bacterial enzyme mixture 100 is configured as the core, the sealing isolation layer 200 is coated on the outer periphery of the bacterial enzyme mixture 100, the pH-responsive layer 300 is coated on the outer periphery of the sealing isolation layer 200, and the lipid outer layer 400 is coated on the outer periphery of the pH-responsive layer 300, wherein the bacterial enzyme mixture 100 comprises an SOD complex enzyme containing Mn3O4 nanoparticles and a probiotic preparation.

[0041] Specifically, the Mn3O4 nanoparticles have a particle size of 50nm to 100nm, which can enhance the stability of the SOD complex enzyme. The SOD complex enzyme, through the synergistic effect of multiple components, enhances antioxidant, anti-inflammatory, and metabolic regulation functions. The probiotic preparation consists of one or more of Bacillus and Lactobacillus, and can also be other conventional probiotics, which are not limited here. Therefore, the bacterial-enzyme mixture 100, as the core material, achieves multifunctional integration of antioxidant, digestive, antibacterial, and deodorizing effects through the synergistic effect of the probiotic preparation and the enzyme, while simultaneously improving the proportion of livestock and poultry muscle and meat quality, breaking through the functional limitations of traditional microbial additives. The sealing and isolation layer 200, as the film-forming matrix of the capsule shell, forms a physical barrier, encapsulates the core material, and achieves isolation and protection functions. The pH-responsive layer 300 is a material layer that changes according to the pH value of the environment. It is stable in the acidic environment of the stomach (pH≈1-3), thus preventing the drug from being destroyed by stomach acid. Furthermore, when it reaches the alkaline environment of the intestines (pH≈6-8), the layer structure disintegrates to release the drug, improving absorption efficiency. The pH-responsive layer 300 can be made of polyethylene glycol derivatives, poly(dimethylaminoethyl methacrylate), gelatin, etc., and its specific composition is not limited here. The lipid outer layer 400 only dissolves in stomach acid when the temperature exceeds 40°C, while maintaining structural stability at body temperature around 37°C or lower. This dual regulation of stability in an acidic environment and dissolution at high temperatures allows for precise control of the release of contents.

[0042] In some embodiments, the sealing isolation layer 200 is a film layer formed by sequentially spraying sodium alginate solution and CaCl2 solution.

[0043] Specifically, a sodium alginate solution is sprayed first, followed by a CaCl2 solution, to form a stable network gel structure, which can achieve a better isolation effect.

[0044] In some embodiments, the pH-responsive layer 300 is configured as a sodium alginate-chitosan composite gel.

[0045] Specifically, the pH-responsive layer is set as a sodium alginate-chitosan composite gel, which can disintegrate when the pH value is greater than 6, facilitating the survival of microcapsules 10 in the acidic environment of the stomach. The thickness of the sodium alginate-chitosan pH-responsive layer 300 is set to 20±2μm.

[0046] In some embodiments, the lipid outer layer 400 is configured as hydrogenated palm oil.

[0047] Specifically, hydrogenated palm oil only disintegrates in the gastric acid environment at a dissolution temperature >40°C, thereby further increasing the survival rate of the bacterial enzyme mixture 100 in the gastric acid environment. The thickness of the lipid outer layer 400 is set to 5 ± 0.5 μm. The lipid outer layer 400 can also be a mixture of hydrogenated palm oil and other substances, but the proportion of hydrogenated palm oil must be ≥60%.

[0048] Conventional probiotics and the microcapsules of this application were tested in simulated gastric acid (pH=2.5) and bile salt (0.3%) environments, and the survival rate of probiotics was detected.

[0049] The results are shown in the table below:

[0050]

[0051] It can be seen that the multi-layer encapsulation design of this application effectively improves the survival rate of probiotics. The survival rate of conventional probiotics under gastric acid conditions is less than 20%, while the survival rate of the probiotics in this application is greater than 78%. Furthermore, the survival rate of the probiotics in the intestines is also much higher than that of conventional probiotics. Therefore, it can be concluded that the design of this application can effectively ensure the survival of probiotics in the intestines. In addition, tests show that the viable bacteria survival rate of the probiotics in this application is still greater than 90% after 180 days of storage at room temperature. Therefore, the microcapsules 10 of this application can greatly improve the survival rate of probiotics; that is, the external double-layer protective design of this application can effectively protect the internal bacterial-enzyme mixture 100, achieving good protective function. The bacterial-enzyme mixture 100 can pass through the poultry stomach to reach the intestines, and through tolerance to the intestinal environment and synergistic metabolism, ultimately promote nutrient absorption, improve intestinal health, and enhance production performance.

[0052] It is worth noting that the microcapsules 10 of this application, through a multi-layer encapsulation design, encapsulate the bacterial enzyme mixture 100 within a core, thereby replacing antibiotics in feed and overcoming the problems of escalating pathogen resistance and drug residues. Furthermore, the multi-layered structure is environmentally friendly and pollution-free, avoiding the heavy metal accumulation and environmental pollution problems that may arise from traditional feed additives, demonstrating significant safety and environmental advantages. In addition, manganese enrichment and multi-layer encapsulation technology enhance the stomach acid tolerance of the microcapsules 10. Therefore, when used, the microcapsules 10 of this application travel from the poultry's stomach to the intestines, and through tolerance to the intestinal environment and synergistic metabolism, ultimately promote nutrient absorption and improve intestinal health. The bacterial enzyme mixture 100 achieves multi-functional integration, including antibacterial, antioxidant, growth-promoting, deodorizing, and meat quality improvement, while also possessing good stomach acid tolerance and environmental friendliness. Simultaneously, it improves the muscle ratio and meat quality of livestock and poultry, enhancing the overall benefits of livestock and poultry farming.

[0053] like Figure 2 As shown, a method for preparing microcapsules is provided, comprising the following steps:

[0054] 110. The sealing and isolation layer is wrapped around the outside of the bacterial enzyme mixture using an embedding machine.

[0055] Specifically, the microencapsulation machine uniformly encapsulates the core material within a sealed isolation layer, forming a closed microcapsule structure to isolate the bacterial enzyme mixture from the external environment. This is achieved by spraying a 2.5% sodium alginate solution followed by a 1.5% CaCl2 solution onto the outer periphery of the bacterial enzyme mixture. When the CaCl2 solution comes into contact with the sodium alginate coating, it significantly increases the contact area, allowing Ca²⁺ to rapidly penetrate into the polymer molecules, instantly initiating a cross-linking reaction. This transforms the linear molecules into a network gel structure, which then solidifies, thereby imparting mechanical strength and stability to the material.

[0056] 120, the pH-responsive layer is encapsulated on the outside of the sealing isolation layer using an embedding machine.

[0057] Specifically, the microencapsulation machine wraps a pH-responsive layer around the outside of the sealed isolation layer to form a primary protective film, thereby improving the survival rate of the bacterial enzyme mixture in the acidic environment of the stomach.

[0058] 130, and then the lipid outer layer is coated on the outside of the pH-responsive layer using an embedding machine, and then cured at low temperature to obtain microcapsules.

[0059] Specifically, the microencapsulation machine wraps the lipid outer layer around the outside of the pH-responsive layer at 45°C and then sets it with cold air at 4°C for 10 minutes to form a second protective film, thereby further improving the survival rate of the bacterial enzyme mixture in the gastric acid environment and obtaining microcapsules with a particle size of 300μm to 500μm.

[0060] like Figure 3 As shown, a feed production method is provided, including the following steps:

[0061] 210. Preparation of SOD complex enzyme.

[0062] Specifically, using okra extract as the induction matrix, the temperature was gradually reduced from 35℃ to 28℃ and maintained for 48 hours during the oxygen-limited phase (DO≤15%) to activate the promoter of the Bacillus amyloliquefaciens SodA gene and obtain the SOD complex enzyme.

[0063] In some embodiments, the SOD complex enzyme is prepared by the following steps:

[0064] Step 1: The raw material of purple okra is ultra-finely pulverized to a particle size corresponding to a sieve mesh size of 2500 mesh, and then subjected to low-temperature extraction at 50℃ and pH=6.0 to obtain purple okra extract. The content of polysaccharides in the purple okra extract is guaranteed to be ≥18% and the content of flavonoids is ≥2.5%.

[0065] Step 2: A composite culture medium consisting of 40% okra extract, 30% soybean meal, and 30% Mn3O4 nanoparticles was prepared and inoculated with Bacillus amyloliquefaciens.

[0066] Step 3: Perform three-stage fermentation on the compound culture medium inoculated with Bacillus amyloliquefaciens: aerobic fermentation: fermentation at 35℃ for 24h, oxygen-limited induction: induction at 28℃ for 48h, low-temperature enzyme production: production at 15℃ for 12h to obtain SOD complex enzyme. The enzyme activity of SOD complex enzyme is ≥8000U / g and contains Mn-SOD and CuZn-SOD.

[0067] Specifically, this solution replaces traditional chemical inducers with active ingredients from okra, utilizing okra polysaccharides and flavonoids as inducers to activate bacterial gene promoters, thereby achieving targeted high-yield SOD complex enzymes and integrating antioxidant, antibacterial, and deodorizing functions. Furthermore, a three-stage fermentation dissolved oxygen-temperature coupling process addresses the SOD yield bottleneck. By replacing imported additives with low-cost, locally sourced raw materials, costs are reduced by 62%, ensuring economic feasibility. Additionally, imported additives require fermentation times exceeding 120 hours, while the fermentation cycle in this embodiment can be shortened to 84 hours, and the SOD yield is increased by 3.2 times compared to conventional single-stage fermentation. Therefore, this solution effectively improves production efficiency and increases output.

[0068] 220. Using SOD complex enzyme and probiotic preparation as the core, microcapsules are sequentially coated with a sealing isolation layer, a pH response layer and a lipid outer layer to obtain microcapsules.

[0069] Specifically, microcapsules are produced using a microcapsule encapsulation machine to obtain gastric acid-resistant microcapsules with a three-layer core-shell structure.

[0070] 230. Add the microcapsules to the basic feed and feed the animals.

[0071] Specifically, microcapsules are mixed with basic feed to prepare finished feed, which is then used to feed poultry.

[0072] 240. The effects were validated through metagenomics, and the functional genes of the strain were analyzed and regulated.

[0073] Specifically, metagenomic technology is applied to precisely analyze the functional genes of the strain, such as the SOD synthesis gene cluster and the expression sequence of antimicrobial peptides, to quantify the mechanism of action. Six to seven functional genes are located through metagenomics, and a mathematical model of feed conversion ratio-gene expression level is established. Furthermore, two key target genes, AvBD9 and MSTN, can be precisely regulated using metagenomic methods, increasing AvBD9 gene expression to ≥200% and controlling MSTN gene inhibition rate at 30%–50%.

[0074] In this embodiment, the specific process of analyzing the functional genes of the strain through metagenomics for effect verification is as follows:

[0075] Step 1: Researchers collect samples of the contents of poultry intestines to complete sample collection.

[0076] Step 2: Following Step 1, researchers extract microbial or host DNA from gut contents samples to provide a template for subsequent genetic analysis.

[0077] Step 3: Following Step 2, metagenomic sequencing is used to analyze the microbial community composition and gene sequences in the sample for gene analysis.

[0078] Step 4: Following Step 3, the expression activity of gene clusters related to superoxide dismutase (SOD) synthesis in the sample was detected to verify whether it plays an antioxidant role in the gut. This was done to perform functional validation.

[0079] Step 5: Following Step 3, detect the presence or expression level of the antimicrobial peptide ituD in the sample to verify its antibacterial effect in the gut. This is for functional validation.

[0080] The results obtained after verifying the above scheme are as follows:

[0081] The microcapsules can activate the host defense peptide AvBD9 gene, increasing its expression level by 230%. This demonstrates that the microcapsules of this application have antibacterial activity.

[0082] The abundance of the thioreductase (dsrA) gene increased 15-fold, and H2S emissions were reduced by 62%. This demonstrates that the microcapsules of this application have a deodorizing effect.

[0083] Myostatin (MSTN) expression decreased by 40%, and pectoral muscle percentage increased by 8.2%. This demonstrates that the microcapsules of this application have an effect on improving meat quality.

[0084] It is worth noting that the feed production method of this application employs a closed-loop technology system of biological induction, physical encapsulation, and gene analysis. Specifically, okra active ingredients are used as the sole inducer to replace traditional chemical inducers; a three-stage fermentation dissolved oxygen-temperature coupling process addresses the SOD production bottleneck; a three-layer microcapsule structure design overcomes the limits of gastric acid tolerance; and a mathematical model of feed conversion ratio-gene expression level achieves predictable results for the first time. This enables the first-ever multifunctional synergistic regulation of antibiotic-free feed, providing a systematic solution to the pain points of antibiotic-free livestock farming.

[0085] A feed is provided, comprising, by weight, 100 parts of basal feed and 0.2 to 0.4 parts of microcapsules.

[0086] Specifically, the basic feed may include one or more mixtures of rice, soybean meal, corn, etc., and may also include other common feeds, without limitation. The microcapsules of this application are mixed with the basic feed in a certain proportion using a biaxial paddle mixer to obtain a mixed feed, wherein the feed has an SOD enzyme activity ≥200 U / k and a viable bacteria count ≥1×10⁻⁶. 9 CFU / g.

[0087] Poultry were fed with both conventional feed and the feed described in this embodiment. Growth indicators and physiological data of the poultry were monitored after feeding. The monitoring results are shown in the table below:

[0088]

[0089] It can be seen that, compared with conventional feed, the feed conversion ratio, abdominal fat percentage, drip loss and NH3 concentration in the chicken house are all lower than those of conventional feed. Therefore, it can be concluded that feed with added microcapsules improves muscle quality, makes poultry meat taste better and improves the air quality of the breeding environment.

[0090] In this invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0091] In the description of this invention, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship commonly used when the product of this invention is in use. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this invention. In addition, the terms "first," "second," "third," etc., are only used to distinguish descriptions and should not be construed as indicating or implying relative importance.

[0092] Furthermore, terms such as "horizontal," "vertical," and "sag" do not imply that components must be absolutely horizontal or suspended, but rather that they can be slightly tilted. For example, "horizontal" simply means that its direction is more horizontal than "vertical," not that the structure must be completely horizontal, but can be slightly tilted.

[0093] In this invention, unless otherwise expressly specified and limited, "above or below" a first feature may include direct contact between the first and second features, or contact between the first and second features through another feature between them. Furthermore, "above," "over," and "on" the first feature includes the first feature directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the first feature includes the first feature directly below or diagonally below the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.

[0094] Although the description of the invention has been given in conjunction with the specific embodiments described above, it will be apparent to those skilled in the art that many substitutions, modifications, and variations can be made based on the foregoing. Therefore, all such substitutions, modifications, and variations are included within the spirit and scope of the appended claims.

Claims

1. A microcapsule, characterized in that, include: A mixture of bacteria and enzymes, a sealing and isolation layer, a pH-responsive layer, and a lipid outer layer; The bacterial enzyme mixture is set as the core, the sealing isolation layer covers the outer periphery of the bacterial enzyme mixture, the pH-responsive layer covers the outer periphery of the sealing isolation layer, and the lipid outer layer covers the outer periphery of the pH-responsive layer. The bacterial enzyme mixture includes SOD complex enzyme containing Mn3O4 nanoparticles and probiotic preparation. The preparation method of the SOD complex enzyme includes: The raw material of purple okra is crushed and extracted to obtain purple okra extract, ensuring that the content of polysaccharides in the purple okra extract reaches more than 18% and the content of flavonoids reaches more than 2.5%. A composite culture medium consisting of 40% okra extract, 30% soybean meal, and 30% Mn3O4 nanoparticles was inoculated with Bacillus amyloliquefaciens. The composite culture medium inoculated with the aforementioned Bacillus amyloliquefaciens was subjected to a three-stage fermentation process: aerobic fermentation: fermentation at 35°C for 24 h, oxygen-limited induction: induction at 28°C for 48 h, and low-temperature enzyme production: production at 15°C for 12 h, to obtain SOD complex enzyme. The SOD complex enzyme has an enzyme activity ≥8000 U / g and contains Mn-SOD and CuZn-SOD.

2. The microcapsule according to claim 1, characterized in that, The sealing and isolation layer is a film formed by sequentially spraying sodium alginate solution and CaCl2 solution.

3. The microcapsule according to claim 1, characterized in that, The pH-responsive layer is a sodium alginate-chitosan composite gel, and the lipid outer layer is hydrogenated palm oil.

4. A method for preparing microcapsules as described in any one of claims 1 to 3, characterized in that, Includes the following steps: The sealing and isolation layer is coated on the outside of the bacterial enzyme mixture using an encapsulation machine; The pH-responsive layer is encapsulated on the outside of the sealing and isolation layer using an embedding machine; The lipid outer layer is then encapsulated on the outside of the pH-responsive layer using an encapsulation machine and cured at low temperature to obtain microcapsules.

5. The method for preparing microcapsules according to claim 4, characterized in that, The step of further encapsulating the outer lipid layer of the pH-responsive layer using an encapsulation machine and then curing it at low temperature to obtain microcapsules also includes: The curing parameters are: 4℃ cold air setting for 10 minutes.

6. A feed, characterized in that, The components include, by weight, 100 parts of basic feed and 0.2 to 0.4 parts of the microcapsules as described in any one of claims 1 to 3.

7. A method for producing feed, characterized in that, Includes the following steps: Using SOD complex enzyme and probiotic preparation as the core, microcapsules are sequentially coated with a sealing and isolation layer, a pH-responsive layer and a lipid outer layer to obtain microcapsules. The microcapsules were added to the basic feed for feeding. The effects were validated through metagenomics, and the functional genes of the strain were analyzed and regulated. The SOD complex enzyme is prepared by the following steps: The raw material of purple okra is crushed and extracted to obtain purple okra extract, ensuring that the content of polysaccharides in the purple okra extract reaches more than 18% and the content of flavonoids reaches more than 2.5%. A composite culture medium consisting of 40% okra extract, 30% soybean meal, and 30% Mn3O4 nanoparticles was inoculated with Bacillus amyloliquefaciens. The composite culture medium inoculated with the aforementioned Bacillus amyloliquefaciens was subjected to a three-stage fermentation process: aerobic fermentation: fermentation at 35°C for 24 h, oxygen-limited induction: induction at 28°C for 48 h, and low-temperature enzyme production: production at 15°C for 12 h, to obtain SOD complex enzyme. The SOD complex enzyme has an enzyme activity ≥8000 U / g and contains Mn-SOD and CuZn-SOD.

8. A feed production method according to claim 7, characterized in that, In the step of pulverizing and extracting the okra raw material to obtain okra extract, ensuring that the content of polysaccharides in the okra extract reaches more than 18% and the content of flavonoids reaches more than 2.5%: The material is pulverized using ultra-fine grinding technology to a particle size corresponding to a sieve mesh size of 2500 mesh.

9. A feed production method according to claim 7, characterized in that, In the step of pulverizing and extracting the okra raw material to obtain okra extract, ensuring that the content of polysaccharides in the okra extract reaches more than 18% and the content of flavonoids reaches more than 2.5%: The extraction parameters were: temperature 50℃, pH=6.0.

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