Black Soldier Fly Bioconversion to Cultivated Meat Media Components Using Blue Catfish Gut Microbiome

Abstract

Developing low-cost media is one of the major challenges in the cellular agriculture domain. Thus, this study aimed to develop low-cost media for cell-cultivated seafood using gut-microbial community-assisted fermentation. Black soldier fly larvae (Hermetia illucens) were used as the substrate and exposed to gut microbial communities isolated from Blue catfish (Ictalurus furcatus). In the first step, BSFL slurry was subjected to enzymatic digestion, using pepsin and trypsin to mimic animal digestive processes. The results showed a 2.8% degree of hydrolysis after digestion with pepsin and an additional 5.9% after digestion with trypsin. In the second step, two fermentation approaches were tested, including the direct addition of gut homogenate to the hydrolysates (fermentation A) and the establishment of microbial cultures from the gut homogenate before fermentation (fermentation B). Both fermentations resulted in similar protein content and degree of hydrolysis. Fermentation led to a decrease in species richness, with the loss of important chitinase and protease-producing genera such as Pseudomonas and Clostridiaceae. However, there was an increase in Paraclostridium and members of the Enterobacteriaceae. In addition, the effect of fermented hydrolysates from BSFL on the proliferation of zebrafish embryo fibroblasts was tested in comparison to fetal bovine serum (FBS) in in vitro cell cultivation. Lower concentrations of FBS resulted in decreased cell density and altered cell morphology. The supplementation of hydrolysate B at high peptide concentrations had cytotoxic effects on the cells, while at lower peptide concentrations, it improved cell proliferation only in cultures with 2.5% FBS.