Synergistic Interactions Between Black Soldier Fly Larvae and Thiobacillus thioparus Beijerinck 1904 for Ammonia Odor Control in Food Waste Bioconversion

Black Soldier Fly larvae (BSFL, Hermetia illucens) are highly effective for the bioconversion of food waste. However, their rearing process often produces substantial ammonia emissions, which are malodorous and environmentally concerning. We investigated the co-cultivation of BSFL with the sulfur-oxidizing bacterium Thiobacillus thioparus as a strategy to mitigate ammonia release. Importantly, under conditions where ammonia emissions were significantly reduced, neither larval growth nor bacterial viability was negatively affected. Furthermore, even when the initial bacterial inoculum was reduced to 3.3*105 CFU/g-food wastes, the bacterium rapidly recovered to functional levels and effectively controlled ammonia emissions. This indicates the absence of harmful interaction or nutrient competition between BSFL and T. thioparus. These findings suggest an efficient method for controlling ammonia in large-scale BSFL waste treatment. By reducing the required bacterial inoculum, this approach enables scalable microbial co-culturing with environmental and production benefits.