A method for environmentally friendly breeding of black soldier flies using fruit and vegetable waste

Abstract

The present invention relates to the technical field of invertebrate breeding or farming, and in particular to a method for environmentally friendly breeding of black soldier flies using fruit and vegetable waste. The present invention uses fruit and vegetable waste, such as sweet potato residue, straw crushed and sesame residue, as feed for black soldier flies. These feeds can promote the growth of black soldier flies, wherein sesame residue increases the protein and fat content, and straw crushed increases the fluffiness and air permeability of the material, which helps the black soldier flies to feed better. Fermentation of these mixed materials can produce enzymes, which help the black soldier flies to better digest substances such as cellulose, and may produce substances that are beneficial to health. Raising black soldier flies in this way can improve their survival rate and yield.

Description

Technical Field

[0001] The invention relates to the technical field of invertebrate breeding or farming, and in particular to a method for environmentally friendly breeding of black soldier flies by utilizing fruit and vegetable waste. Background Art

[0002] Black soldier fly, scientific name Hermetia illucents , is a resource insect belonging to the family Soldierfly of the order Diptera, known by its nickname of the bright-spotted flat-horned soldier fly. This insect is native to the tropical grasslands of South America and feeds on animal feces and carcasses. Over time, they have spread to all parts of the Americas and are widely distributed in tropical, subtropical and temperate regions around the world. The life cycle of the black soldier fly includes four stages: egg, larva, pupa and adult, and it is a completely metamorphosed insect. Their life cycle is about 30 to 40 days, and they can reproduce up to 10 times a year. The appearance of the adult is similar to that of a bee, with a body length of about 13 to 22 mm. The black soldier fly is non-toxic and harmless to humans, can inhibit the reproduction of house flies and blow flies, and its larvae can also prey on other young larvae. In the adult stage, because they do not eat, their energy consumption is low, their flying ability is not strong, they do not like to approach humans, and they are not attracted to human settlements and food, which makes their relationship with humans more harmonious. Due to their fast reproduction rate, large biomass, wide diet, high absorption conversion rate, easy management and low breeding cost, black soldier flies are known as environmentally friendly insects and are also recognized as resource insects by the Food and Agriculture Organization of the United Nations (FAO). They can eat organic waste such as poultry and livestock manure and domestic garbage, convert them into their own nutrition, effectively reduce environmental pollution, and are widely used for resource utilization.

[0003] Black soldier flies can be raised using fruit and vegetable waste. As a resource insect, the larvae of black soldier flies feed on various organic wastes, including livestock manure, kitchen waste, and agricultural and sideline product scraps. In particular, during the feeding process, black soldier fly larvae can efficiently convert the nutrients in the food into their own nutrients, while also digesting and decomposing the harmful bacteria in it, reducing environmental pollution. In addition, black soldier fly larvae have strong adaptability and bioconversion efficiency to environments with high salt, high oil, and high moisture content, which makes them very efficient in handling wet garbage, including fruit and vegetable garbage. Therefore, fruit and vegetable garbage can not only serve as a food source for black soldier flies, but also achieve resource utilization of garbage and environmental protection through this process.

[0004] CN111066733B discloses a method for breeding black soldier flies by preparing feed with organic perishable garbage. The method uses organic perishable garbage as the feeding raw material, and is equipped with a variety of auxiliary materials and composite strains with optimized design, so as to realize the efficient breeding of black soldier flies. The breeding method of the invention can meet the requirements of black soldier fly breeding, improve the feeding efficiency and survival rate of black soldier fly larvae, and make full use of the nutrients in organic perishable garbage to realize rapid conversion and utilization. The invention reutilizes waste resources such as organic perishable garbage, straw, bean dregs, etc., is simple to operate, low in cost, low in carbon and environmentally friendly, and has high economic value, and provides a basic solution for the large-scale and industrialized breeding of black soldier flies.

[0005] CN115176766B discloses a method and application of using food waste to feed black soldier fly larvae. The method of using food waste to feed black soldier fly larvae is as follows: first, black soldier fly eggs are hatched to obtain black soldier fly larvae, then the food waste is chopped, heated, stirred, and mixed with mineral gel to feed the black soldier fly larvae. The method is applied to the treatment of food waste and the production of black soldier fly protein feed. Compared with the prior art, the method of using food waste to feed black soldier fly larvae has better biocompatibility, enhances antioxidant properties and immune activity, promotes the growth of black soldier fly body size, improves survival rate, and can also reduce the pollution of food waste, turn waste into treasure, and convert food waste into high-efficiency fertilizer and high-protein feed, with considerable economic benefits.

[0006] Existing black soldier fly breeding often adds bacteria to ferment to obtain bacterial liquid, thereby improving the utilization rate of kitchen waste or fruit and vegetable waste as feed. However, the stacking of a large amount of organic waste and black soldier fly larvae will not only cause poor living conditions (such as air circulation is difficult, or only the black soldier fly larvae on the surface are sprayed, and water is difficult to penetrate into the lower layer, etc.), but also affect the efficiency of bacterial fermentation, making it difficult to provide black soldier flies with a good growth environment, thereby affecting their survival rate and growth rate. Summary of the invention

[0007] In view of the above-mentioned defects of the prior art, the technical problem to be solved by the present invention is to provide a method for environmentally friendly breeding of black soldier flies using fruit and vegetable waste.

[0008] Using inert carrier particles that cannot be used by fermenting microorganisms and have the ability to adsorb and retain water, the liquid culture medium is adsorbed inside and on the surface for the growth and metabolism of microorganisms. Compared with traditional solid fermentation, adsorption carrier solid fermentation has the advantages of good permeability of the material bed, not easy to harden, easy to adjust the composition of the culture medium, more sufficient oxygen supply, easier to separate the product, and some inert carriers can be reused, and has great application potential. Polyurethane has high porosity and high specific surface area, can be used to fix microorganisms, has good mechanical strength and lower cost. If polyurethane is used as a carrier in the breeding of black soldier flies, it can not only provide a large number of sites for the growth and reproduction of microorganisms, but also provide conditions for enrichment of black soldier flies. However, the hydrophilic and biophilic properties of polyurethane are poor, making it difficult for microorganisms to attach to the surface of the carrier, which will affect the loading rate to a certain extent. Therefore, the present invention provides a modified polyurethane, wherein allyl chloride and N-methyldiethanolamine are used to prepare hydrophilic and positively charged quaternary ammonium salt as a chain extender to synthesize modified waterborne polyurethane, and a carrier with high porosity and high specific surface area is obtained after foaming, and the carrier is mixed with feed and laid in a breeding box, which can not only provide a more sufficient oxygen supply environment for the strains, but also its large number of fertile sites are also conducive to the fermentation growth of the strains, and improve the living conditions of black soldier fly larvae, so that nutrients are more sufficient and air is more circulated. The modified polyurethane is not only highly hydrophilic, but also electrophilic. The charged functional groups are modified on the surface of the polyurethane to improve its surface charging ability, which can interact with the charge on the surface of the microorganism, reduce the repulsive force between the microorganism and the carrier, and the improvement of hydrophilicity can improve the biological hydrophilicity, thereby being more conducive to the growth of microorganisms in the polyurethane.

[0009] The present invention utilizes common fruit and vegetable garbage sweet potato residue, straw shreds, and sesame residues as feed for black soldier flies, and the feed containing sweet potato residues and straw shreds has a promoting effect on the growth and development of black soldier flies. In addition, sesame residues can increase the protein and fat content in the feed to meet the feeding level of black soldier flies, while straw shreds help to increase the fluffiness and air permeability of the material, adjust the moisture content, and improve the feeding efficiency of black soldier flies. These mixed materials are fermented, and the enzymes produced by microorganisms can decompose complex organic matter such as cellulose, hemicellulose and lignin in sweet potato residues, straw shreds and sesame residues, and convert them into nutrients that are easier for black soldier flies to digest and absorb. In addition, some microorganisms can also produce substances that promote intestinal health and enhance immunity, which are beneficial to the growth and development of black soldier flies. The mixed material is mixed with modified polyurethane and then raised to black soldier flies, which can not only improve the survival rate of black soldier flies, but also increase the yield.

[0010] To achieve the above object, the present invention provides a method for environmentally friendly breeding of black soldier flies using fruit and vegetable waste, comprising the following steps:

[0011] S1, mixing sweet potato residue, straw residue and sesame residue, crushing and sieving, controlling the moisture content to 75-85%, to obtain a mixed material;

[0012] S2. Mix the mixed material with the modified polyurethane, mix the material evenly, then spread it in a breeding box, add the composite bacteria for fermentation, inoculate 2-5kg of 2-3 instar black soldier fly larvae per 100kg of feed, inoculate the larvae into the breeding box, and culture them at 25-30° C. until the first black soldier fly larvae become black soldier fly prepupae, then stop culturing to obtain black soldier flies.

[0013] Furthermore, the mass ratio of the sweet potato residue, the straw residue and the sesame residue is 50-80:10-30:5-15.

[0014] Furthermore, the sieved particle size is 0.5~5mm.

[0015] Furthermore, the added amount of the modified polyurethane accounts for 10-20wt% of the total amount.

[0016] Furthermore, the composite bacteria is a mixture of Candida utilis, Bacillus licheniformis, Aspergillus niger and Trichoderma harzianum in a mass ratio of 30-40:10-20:15-20:20-30.

[0017] Furthermore, the inoculation amount of the composite bacteria is 1-2wt% of the total amount.

[0018] Furthermore, the fermentation temperature is 25-30° C., stirring is performed every 2 hours, and fermentation is performed for 6-12 days.

[0019] The preparation method of the modified polyurethane comprises the following steps:

[0020] X1. Mix allyl chloride and N-methyldiethanolamine, raise the temperature to 40-55°C and stir for 1-3 hours. After stirring, cool to 0-5°C for crystallization. Vacuum concentrate the residue to dry and use in the next step.

[0021] X2. Mix isophorone diisocyanate and polypropylene glycol and heat to 80-90°C, then add dibutyltin dilaurate, continue stirring evenly, add 10wt% N-methylpyrrolidone solution of the product of the previous step, water, and foam stabilizer, stir and homogenize to obtain a modified water-based foaming polyurethane, which can be obtained by crushing.

[0022] Furthermore, the molar ratio of the allyl chloride to N-methyldiethanolamine is 1:1-2.

[0023] Furthermore, the mass ratio of isophorone diisocyanate, polypropylene glycol, dibutyltin dilaurate, the product of the previous step, water, and foam stabilizer is 20-30:4-20:0.1-0.5:2-10:0.01-1:0.5-2.5.

[0024] Beneficial effects of the present invention:

[0025] The present invention utilizes common fruit and vegetable garbage sweet potato residue, straw shreds, and sesame residues as feed for black soldier flies, and the feed containing sweet potato residues and straw shreds has a promoting effect on the growth and development of black soldier flies. In addition, sesame residues can increase the protein and fat content in the feed to meet the feeding level of black soldier flies, while straw shreds help to increase the fluffiness and air permeability of the material, adjust the moisture content, and improve the feeding efficiency of black soldier flies. These mixed materials are fermented, and the enzymes produced by microorganisms can decompose complex organic matter such as cellulose, hemicellulose and lignin in sweet potato residues, straw shreds and sesame residues, and convert them into nutrients that are easier for black soldier flies to digest and absorb. In addition, some microorganisms can also produce substances that promote intestinal health and enhance immunity, which are beneficial to the growth and development of black soldier flies. The mixed material is mixed with modified polyurethane and then raised to black soldier flies, which can not only improve the survival rate of black soldier flies, but also increase the yield. DETAILED DESCRIPTION

[0026] Candida utilis CGMCC2.3048, Bacillus licheniformis CGMCC1.9048, Aspergillus niger CGMCC3.15663 and Trichoderma harzianum CGMCC5.1233 were all purchased from China General Microorganism Collection Center.

[0027] Polypropylene glycol, Mw=1000, Tianjin Petrochemical.

[0028] Foam stabilizer, RAYNOL PM-933, Zibo Ruinuo Chemical.

[0029] Example 1

[0030] A method for environmentally friendly breeding of black soldier flies using fruit and vegetable waste comprises the following steps, measured in parts by weight:

[0031] S1, mix 60 parts of sweet potato residue, 20 parts of straw shreds, and 10 parts of sesame residues, and grind them through a 2 mm sieve to control the moisture content to 75% to obtain a mixed material;

[0032] S2, the mixture is mixed with 15wt% modified polyurethane, the material is mixed evenly, and then laid in a breeding box, 1.5wt% composite bacteria is added for fermentation, the composite bacteria is a mixture of Candida utilis, Bacillus licheniformis, Aspergillus niger and Trichoderma harzianum in a mass ratio of 30:15:20:25, the fermentation temperature is 27 ° C, stirring once every 2 hours, fermentation for 10 days, 3kg of 3rd instar black soldier fly larvae are inoculated per 100kg of feed, the larvae are inoculated into a breeding box, and cultured at 28 ° C until the first black soldier fly larvae become black soldier fly prepupae and the culture is stopped to obtain black soldier flies.

[0033] The preparation method of the modified polyurethane comprises the following steps, measured in parts by weight:

[0034] X1. Mix allyl chloride and N-methyldiethanolamine in a molar ratio of 1:1.5, heat to 50°C and stir for 2h. After stirring, cool to 0°C for crystallization. Vacuum concentrate to obtain a residue that is dried and used in the next step.

[0035] X2. Mix 25 parts of isophorone diisocyanate and 15 parts of polypropylene glycol, heat to 85°C, add 0.3 parts of dibutyltin dilaurate, continue stirring evenly, add 50 parts of 10wt% N-methylpyrrolidone solution of the product of the previous step, 0.05 parts of water, and 1.5 parts of foam stabilizer, stir and homogenize to obtain a modified water-based foaming polyurethane, which can be obtained after crushing.

[0036] Example 2

[0037] It is basically the same as Example 1, the only difference being that the amount of modified polyurethane added accounts for 10wt% of the total amount.

[0038] Example 3

[0039] It is basically the same as Example 1, the only difference being that the amount of modified polyurethane added accounts for 20wt% of the total amount.

[0040] Comparative Example 1

[0041] A method for environmentally friendly breeding of black soldier flies using fruit and vegetable waste comprises the following steps, measured in parts by weight:

[0042] S1, mix 60 parts of sweet potato residue, 20 parts of straw shreds and 10 parts of sesame residues, and grind them through a 2 mm sieve to control the moisture content to 75% to obtain a mixed material;

[0043] S2, the mixture is mixed with 15wt% polyurethane, the material is mixed evenly, and then laid in a breeding box, 1.5wt% composite bacteria is added for fermentation, the composite bacteria is a mixture of Candida utilis, Bacillus licheniformis, Aspergillus niger and Trichoderma harzianum in a mass ratio of 30:15:20:25, the fermentation temperature is 27 ° C, stirring once every 2 hours, fermentation for 10 days, 3kg of 3rd instar black soldier fly larvae are inoculated per 100kg of feed, the larvae are inoculated into a breeding box, and cultured at 28 ° C until the first black soldier fly larvae become black soldier fly prepupae and the culture is stopped to obtain black soldier flies.

[0044] The preparation method of the polyurethane comprises the following steps, measured in parts by weight:

[0045] 25 parts of isophorone diisocyanate and 15 parts of polypropylene glycol are mixed and heated to 85°C, and then 0.3 parts of dibutyltin dilaurate are added. After continuing to stir evenly, 50 parts of 10wt% 2,2-dihydroxymethylpropionic acid N-methylpyrrolidone solution, 0.05 parts of water, and 1.5 parts of foam stabilizer are added. After stirring and homogenizing, polyurethane is obtained, which is obtained after crushing.

[0046] Comparative Example 2

[0047] It is basically the same as Example 1, the only difference being that no modified polyurethane is added.

[0048] Test Example 1

[0049] The survival rates of the black soldier flies raised in the control examples and the embodiments were statistically analyzed, and the number of surviving black soldier flies after the cultivation was completed was statistically analyzed. Compared with the inoculated black soldier fly larvae, the survival rate was calculated. The specific results are shown in Table 1.

[0050]

[0051] Test Example 2

[0052] The weight of the black soldier fly larvae at the beginning of the culture and the weight of the black soldier fly larvae after the culture was completed in the control example and the embodiment were recorded, and the weight growth rate of the black soldier fly was calculated by the difference between the weight of the black soldier fly adults and the weight of the larvae after the culture was completed and the ratio of the weight of the larvae, and the weight was averaged. The specific results are shown in Table 2.

[0053]

[0054] By comparing Reference Example 2 with the embodiment, it can be found that the addition of modified polyurethane has a significant effect on the growth and survival of black soldier fly larvae. This is because the stacking of a large amount of organic garbage and black soldier fly larvae in the current breeding environment will not only cause poor living conditions (such as air is difficult to circulate, or only the surface black soldier fly larvae are sprayed, and water is difficult to penetrate into the lower layer, etc.), but also affect the efficiency of bacterial fermentation, and it is difficult to guarantee a good growth environment for black soldier flies, thereby affecting its survival rate and growth rate. In the embodiment, a polyurethane carrier with high porosity and high specific surface area is obtained after foaming, and it is laid in a breeding box after mixing it with feed, which can not only provide a more sufficient environment for oxygen supply to the bacterial species, but also its large number of fertile sites are also conducive to the fermentation growth of the bacterial species and improve the living conditions of the black soldier fly larvae, so that nutrients are more sufficient and air is more circulated, thereby resulting in an increase in the survival rate of black soldier flies, and better growth and development. In the embodiment, the modified polyurethane is not only highly hydrophilic, but also electrophilic. Modifying the charged functional groups on the surface of polyurethane to improve its surface charging ability can interact with the charges on the surface of microorganisms and reduce the repulsive force between microorganisms and carriers, while the improvement of hydrophilicity can improve the biological hydrophilicity, which is more conducive to the growth of microorganisms in polyurethane. In Control Example 1, no positively charged quaternary ammonium salt was prepared, so the electrophilicity was not as good as that of Example 1, while the test results of Examples 2-3 showed that the addition amount in Example 1 was relatively better.

[0055] The present invention utilizes common fruit and vegetable garbage sweet potato residue, straw shreds, and sesame residues as feed for black soldier flies, and the feed containing sweet potato residues and straw shreds has a promoting effect on the growth and development of black soldier flies. In addition, sesame residues can increase the protein and fat content in the feed to meet the feeding level of black soldier flies, while straw shreds help to increase the fluffiness and air permeability of the material, adjust the moisture content, and improve the feeding efficiency of black soldier flies. These mixed materials are fermented, and the enzymes produced by microorganisms can decompose complex organic matter such as cellulose, hemicellulose and lignin in sweet potato residues, straw shreds and sesame residues, and convert them into nutrients that are easier for black soldier flies to digest and absorb. In addition, some microorganisms can also produce substances that promote intestinal health and enhance immunity, which are beneficial to the growth and development of black soldier flies. The mixed material is mixed with modified polyurethane and then raised to black soldier flies, so that the survival rate and weight of black soldier flies are improved.

[0056] The preferred specific embodiments of the present invention are described in detail above. It should be understood that a person skilled in the art can make many modifications and changes based on the concept of the present invention without creative work. Therefore, any technical solution that can be obtained by a person skilled in the art through logical analysis, reasoning or limited experiments based on the concept of the present invention on the basis of the prior art should be within the scope of protection determined by the claims.

Claims

1. A method for environmentally friendly breeding of black soldier flies using fruit and vegetable waste, characterized in that: The steps include: S1, mixing sweet potato residue, straw shreds and sesame residues, crushing and sieving, controlling the moisture content to 75-85%, to obtain a mixed material; S2, mixing the mixed material with the modified polyurethane, mixing the material evenly, then laying it in a breeding box, adding the composite bacteria for fermentation, inoculating 2-5 kg ​​of 2-3 instar black soldier fly larvae per 100 kg of feed, inoculating the larvae into the breeding box, and culturing at 25-30° C. until the first black soldier fly larvae become black soldier fly prepupae, and then stopping the cultivation to obtain black soldier flies; The preparation method of the modified polyurethane comprises the following steps: X1. Mix allyl chloride and N-methyldiethanolamine, raise the temperature to 40-55°C and stir for 1-3 hours. After stirring, cool to 0-5°C for crystallization. Vacuum concentrate the residue and dry it for the next step. X2. Mix isophorone diisocyanate and polypropylene glycol and heat to 80-90°C, then add dibutyltin dilaurate, continue to stir evenly, add 10wt% N-methylpyrrolidone solution of the product of the previous step, water, and foam stabilizer, stir and homogenize to obtain a modified water-based foaming polyurethane, and crush to obtain; The molar ratio of allyl chloride to N-methyldiethanolamine is 1:1-2; The mass ratio of the isophorone diisocyanate, polypropylene glycol, dibutyltin dilaurate, the product of the previous step, water, and the foam stabilizer is 20-30:4-20:0.1-0.5:2-10:0.01-1:0.5-2.

5.

2. The method for environmentally friendly breeding of black soldier flies using fruit and vegetable waste as claimed in claim 1, characterized in that: The mass ratio of the sweet potato residue, the straw shreds and the sesame residue is 50-80:10-30:5-15.

3. The method for environmentally friendly breeding of black soldier flies using fruit and vegetable waste as claimed in claim 1, characterized in that: The sieved particle size is 0.5-5 mm.

4. The method for environmentally friendly breeding of black soldier flies using fruit and vegetable waste as claimed in claim 1, characterized in that: The added amount of the modified polyurethane accounts for 10-20wt% of the total amount.

5. The method for environmentally friendly breeding of black soldier flies using fruit and vegetable waste as claimed in claim 1, characterized in that: The composite bacteria is a mixture of Candida utilis, Bacillus licheniformis, Aspergillus niger and Trichoderma harzianum in a mass ratio of 30-40:10-20:15-20:20-30.

6. The method for environmentally friendly breeding of black soldier flies using fruit and vegetable waste as claimed in claim 1, characterized in that: The inoculation amount of the composite bacteria is 1-2 wt % of the total amount.

7. The method for environmentally friendly breeding of black soldier flies using fruit and vegetable waste as claimed in claim 1, characterized in that: The fermentation temperature is 25-30° C., stirring is performed every 2 hours, and the fermentation is performed for 6-12 days.

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