19 / 2023-04-28 14:04:39

Revealing the relationship between substrate properties and gut microorganisms to enhance the bioconversion of food waste by black soldier fly (Hermetia illucens) larvae

Food waste,Black sodier fly,Bioconversion,Substrate properties,Gut micoorganism,Insect protein

The increasing amount of food waste (FW) has led to serious resource waste and environmental pollution. Black soldier fly larvae (BSFL) are typically insects used to convert FW into insect protein, but a deeper understanding of the relationship between substrate composition and gut microorganism is necessary for better productivity and bioconversion. We investigated the effect of substrate microbial load on yield and gut microorganism of BSFL by feeding FW fermented for different durations (0-10 d). The results suggested that fermentation pretreatment significantly altered the physicochemical properties and microbial structures of FW, while Lactobacillus was always the most dominant genus except in fresh FW. Almost all groups harvested the peak larval biomass after 10 days’ bioconversion. Comparatively, feeding FW fermented for 8 d resulted in a slight increase in BSFL yield, with a maximum weight of 222 mg per larvae. A stable core gut community, dominated by Enterococcus and Klebsiella, ensured efficient BSFL production and FW degradation. Moreover, Enterococcus became increasingly important in the gut as bioconversion proceeded. However, intricate and mutualistic microbial interactions occurred between BSFL gut and fermented FW, resulting in a restructuring of each other’s microbial community. The main evidence was that more unclassified_f_Clostridiaceae found in fermented FW colonized the BSFL gut, while Enterococcus found in the larval gut was observed colonizing the substrate. These findings extend our comprehension of the biological mechanisms involved in efficient FW bioconversion with respect to BSFL gut microbes, providing valuable information for promoting the effective utilization of organic waste resources.