Diet chemistry and cross-kingdom microbiota associate with black soldier fly larvae performance on regional side streams

This study investigates the effects of five different feed treatments—chicken feed (control), apple pomace, potato pulp (industrial and lab-scale), and rapeseed cake—on the growth of black soldier fly larvae (BSFL) from hatching to pupation. Performance differences were linked to the nutrient profiles of the feeds, particularly their protein, fat, and fiber content. For gut microbiota analysis, 16S rRNA gene sequencing was conducted using primers U341F and U806R, specifically targeting the V3-V4 regions to detect both bacteria and Archaea, along with ITS2 amplicon sequencing using primers fITS7 and ITS4. This approach revealed that microbial communities varied according to diet, showing an enrichment of fiber-degrading and nitrogen-fixing bacteria in larvae fed fiber-rich, nitrogen-poor diets. This research highlights the potential of agricultural side streams as effective feed substrates for BSFL production, emphasizing the importance of gut microbiota plasticity in digestion and the significance of feed composition for optimizing large-scale insect farming for sustainable protein production.