Management of chicken manure using black soldier fly (Diptera: Stratiomyidae) larvae assisted by companion bacteria.

• Companion bacteria help black soldier fly larvae (BSFL) reduce manure pollution. • Co-conversion of optimized mixed bacteria and BSFL increase conversion efficiency. • Companion bacteria from BSFL gut could increase protein accumulation in BSFL. Black soldier fly (BSF) is used for the management of organic waste, but research has hardly explored the effect of companion bacteria when chicken manure (CHM) is converted to insect biomass. In this study, we isolated nine bacterial species (FE01, FE02, FE03, FE04, FE05, FE06, FE07, FE08, FE09) from BSF eggs and one (BSF-CL) from the larval gut. These companion bacteria were inoculated into CHM along with BSF larvae (BSFL). Larval growth and manure conversion rates were determined. Results indicated that almost all bacteria individual bacteria in this study significantly promote BSFL growth. BSFL reared in manure with the species Kocuria marina (FE01), Lysinibacillus boronitolerans (FE04), Proteus mirabilis (FE08) and Bacillus subtilis (BSF-CL) had higher weight gain and manure reduction rates compared to the control. These four strains used were then examined as a poly-bacteria community experiment to determine BSFL growth and manure conversion. Manure inoculated with the poly-bacteria Group3 (FE01:FE04:FE08:BSF-CL = 4:1:1:1) and then fed to BSFL resulted in 28.6% more weight gain than the control. The greatest manure reduction rate (52.91%) was reached when companion bacteria were mixed at a ratio of 1:1:1:4. Additionally, the companion bacteria influenced the nutritional value of BSFL. Crude protein content in Group1 (FE01:FE04:FE08:BSF-CL = 1:1:1:1) was significantly larger than that of the control. Crude fat content in Group3 was significantly larger than that of the control. BSFL companion bacteria and their poly-bacteria compound improved manure conversion efficiency and nutrient accumulation in BSFL, reduced CHM quantity, increased larvae biomass, with potential economic gains in CHM management. [ABSTRACT FROM AUTHOR]