The Effect Of Different Sources Microorganisms On The Growth And Development Of Black Soldier Fly And Its Application

The black soldier fly(Hermetia illucens,BSF)is an omnivorous saprophytic insect.It can efficiently use various organic wastes to form high protein and high fat insect bodies,which can be used as feed protein raw materials to solve environmental pollution problems and alleviate the shortage of protein resources in China.Previous studies have confirmed that BSF and gut microbes are essential for their efficient transformation and growth and development,but the relationship between BSF and these microbes,or whether BSF can obtain the assistance of microbes from different growth environments,or whether they can obtain specific groups of microbes,are still unclear.Therefore,in this study,the comparative cultivation test of Germ-free BSFL and normal BSFL and high-throughput sequencing of 16 S r RNA gene were combined to explore the influence of different sources of microorganisms on the growth and development of BSF,analyze the diversity differences of BSFL’ intestinal microorganisms under different culture conditions,and isolate and identify specific microorganisms and verify their application.The experimental results are as follows:(1)The effect of microorganisms from different materials on the growth and development of BSFLThree kinds of materials,including bran feed,chicken manure and kitchen waste,combined Germ-free BSFL(GF)and BSFL raised with sterile and normal materials,measure the growth indexes,and evaluate the influence of exogenous microorganisms on the growth and development of larvae.Exogenous microorganisms in materials can promote the growth of BSFL and significantly restore the growth characteristics.BSFL can get assistance from microorganisms in materials.The growth data of three kinds of materials showed that GF grew best in kitchen materials.With the help of exogenous microorganisms in the kitchen waste,the survival rate of BSFL was increased by 26.95%,the duration of prepupa was shortened by 23.33%,and the average weight of prepupa was increased by 118.50%.(2)The effect of eggs carry microorganisms on the growth and development of BSFLThree kinds of sterilized materials,including bran feed,chicken manure and kitchen waste,combined with GF culture technology,adding egg wash solution to grow to prepupa,compared with the treatment without egg wash solution,measure the growth indexes,and evaluate the influence of exogenous microorganisms on the growth and development of larvae.The microorganisms in the egg wash have a promoting effect on the growth of BSFL.The survival rate of GF reared on bran and kitchen waste was significantly increased by 17.00% and 19.66% after exogenously added egg wash.The survival rate of GF reared on sterile chicken manure was increased but not significantly.In the three kinds of materials,the microbe on egg surface can shorten the prepupa duration of GF,and the bran has the most significant effect,reducing the prepupa duration by 21.17%,while the food material has the most significant effect on promoting growth,increasing the average body weight by106.50%.BSFLcan get assistance from egg carry microorganisms,which can promote the growth of themselves.(3)Comparative analysis of intestinal bacterial diversity of BSFL reared with different materialsThe intestines of larvae from each treatment group were dissected,and 16 S r RNA gene sequencing was performed to analyze the characteristics of intestinal microbial colonization.The GF was reared in three kinds of materials and with egg wash,Firmicutes was a kind of bacteria that was selected directionally in the rearing process.Firmicutes and Actinomycetes were the core phyla in each treatment group.The GF was grown in three kinds of materials,Clostridium sensu stricto 1being the core bacterium.Among the three material groups,the core bacteria were Actinomyces,Enterococcus,unclassified f Lachnospiraceae,Clostridium sensu stricto1.(4)Isolation and application validation of intestinal microorganisms of BSFL reared with different materialsCombined with the analysis of intestinal 16 S r RNA gene sequencing data,Bacillus subtilis strain,Bacillus velesiensis strain,Enterococcus avium strain,and Enterococcus wangshanyuanii strain were screened.Mixed and prepared as additives,the additives were then added back to germ free,measured the growth index,and the return effect was verified.The microbial additive has a significant effect on the growth promotion of BSFL.The survival rate was increased by 13.00%,the duration of prepupa was shortened by 46.44%,and the average body weight was increased by201.51%.In conclusion,BSF can obtain the assistance of specific microorganisms from different environments.The results of this paper provide a reference for further exploring the interaction between host and microbe of BSF.The development of mixed microbial agents for these BSF intestinal microbes will help to improve the growth and development speed of BSF,provide a new additive for the future BSF breeding,and promote the healthy development of BSF industry.