Effect of Bokashi fermentation on the microbiome of larvae and frass of the black soldier fly Hermetia illucens.

Fermentation technology can enhance the digestibility of the substrate for insects used to digest biowaste such as the black soldier fly (BSF) Hermetia illucens (Diptera: Stratiomyidae) and lead to improved performance and higher protein yields. The Bokashi fermentation is a method of treating biowaste using a mixed culture of microorganisms such as lactobacilli, yeasts and fungi under anaerobic conditions. When substrates are inoculated with such microorganisms the microbial equilibrium shifts to create an improved microbiome, with secondary metabolites produced by the modified microbiome that can perform beneficial functions, including breaking down harmful chemicals and immobilizing heavy metals. Using a commercially available Bokashi starter, we anaerobically digested two organic substrates, fresh oranges and brewery’s spent grains, and the Gainesville diet used a control, with the goal of assessing the impact of the fermented solid fraction on the microbiome composition of both BSF larval guts and of substrates (before and after BSF digestion). I will present the remarkable effects of both Bokashi fermentation and BSF digestion on the microbiome of BSF guts and on substrates, respectively.