| With the rapid development of livestock and poultry breeding industry,the resulting livestock and poultry manure has caused serious pressure on the environment.At present,attention has been paid to the use of insects to deal with fecal pollution.The study of insect control technology,on the one hand,can reduce the activity of heavy metals in feces,thus reducing the harm to the soil;on the other hand,the fecal residues(that is insect sand)after feeding insects,the content of organic matter can still reach or even higher than the standard of organic fertilizer and has the potential to produce high-efficiency organic fertilizer.The black water gadfly(Hermitia illucens)is an insect of the genus Diptera,the genus Diptera and the flat-horned gloom.The whole life process includes four developmental stages: egg,larva,pupa and adult.The black water gadfly larva mainly feeds on livestock and poultry droppings,kitchen waste and decomposing animal carcasses,and the whole development process can be completed in 28 days under the most suitable growth environment.At present,the research on the application of black water gadfly at home and abroad is mainly focused on two aspects,resource utilization and feed additive or directly instead of feed.In this paper,the 4-day-old black water gadfly larvae were fed with fresh pig manure for 10 days,and the microorganisms were isolated from the intestine of the black water gadfly.The isolated microorganisms were identified by configuring different nutrient types of medium,and the 16S rDNA and gyr B genes of different nutrient types of microorganisms were sequenced to analyze their genetic and evolutionary relationship and determine the optimal growth environment.After fermenting pig manure with different nutritional strains at the optimum growth temperature for 4 days,the4-day-old black water gadfly larvae were fed,and the whole process of producing prepupa,pupa and eclosion was recorded to explore the effects of fresh pig manure on the growth and development of black water gadfly at different stages after microbial fermentation.The experimental results are as follows:1.A total of 11 strains with different morphology were isolated from the intestines of black water gadfly larvae fed with fresh pig manure for 10 days.The results of culture type identification showed that strains L2,L5,L6,F2,F5 and F6 could produce cellulolytic enzyme,strain L5 had the highest activity of producing cellulolytic enzyme at 43℃,strain L2,L4,L5,F2,F5 and F6 produced casein hydrolytic enzyme,strain L2 produced the highest activity of proteolytic enzyme,strain L2 produced organophosphorus lyase activity,strain L2 produced the highest activity of organophosphorus hydrolytic enzyme.2.16S rDNA evolution analysis showed that the Strain L2 with high enzyme activity had the highest similarity with Pectbacterium carotovorum strain LMG 2404,and strain L5 had the highest similarity with Serratia liquefaciens strain ATCC 27592.The optimum growth temperatures of strains L2 and L5 were 37 and 28 ℃ ℃,respectively,and entered the logarithmic growth phase in about 4 h,and basically entered the plateau stage in 12 h—16 h.3.Fermented pig manure could increase the weight of prepupa and pupa,but had no significant effect on eclosion.Fermented pig manure could increase the weight of prepupa of black water gadfly by 15.87%,the emergence rate of black water gadfly in the control group was the highest,the life span of male was generally higher than that of female,and the pupation rate of black water tabanus treated with unsterilized L2 was significantly higher than that of the control group.the duration of pupation of black water tabanus in the control group was the longest.The time required for 90% pupae Eclosion was significantly different from that of the control group.Among them,90% pupae Eclosion time was the shortest in non-sterilized L5 treatment,followed by sterilized L5 treatment.Conclusion: After 16S rDNA identification of the microorganisms isolated from the intestines of the black water gadfly larvae,it was found that the strains L2 and L5 with the highest enzyme activity belonged to Bacillus,strain L2 had the highest activity of proteolytic enzyme and organophosphorus enzyme,and strain L5 had the highest activity of cellulolytic enzyme.The pig manure treated by strains L2 and L5 could significantly increase the weight of prepupa and the pupation rate of black water tabanus,but had no effect on the emergence of black water gadfly.Therefore,the weight of prepupa of black water gadfly can be increased by adding intestinal microorganisms to pig manure. |
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