Abundance and phylogenetic diversity of the intestinal bacterial community in the food waste reducing larvae of Hermetia illucens

As it is known that food waste can be reduced by larval Hermetia illucens (Black Soldier Fly, BSF), the scientific and commercial value of larval BSF is increased recently. We focused one of the reasons that ability of catabolic degradation might be caused by intestinal microorganisms, here we analyzed bacterial community of BSF larval gut. We extracted their intestinal metagenomic DNAs from each larva provided with three different nutrients. We performed polymerase chain reactions (PCR) by using bacterial 16S rRNA primers and pyrosequencing for the analysis of intestinal microbial community. We got the 16S rRNA sequence data set of 9737, 9723, and 5985 sequences from the PCR products of three different fed samples, food waste, cooked rice, and calf forage, respectively. On the basis of the BLAST search of EzTaxon program, the bacterial community of the food waste fed gut was revealed that the phyrum Bacteroidetes had dominancy of 67.6%, Proteobacteria of 18.7%, and Firmicutes of 9.6%. The phylogenic groups from cooked rice fed gut were two dominant phyrums of Firmicutes (42.64%) and Proteobacteria (54.47%). The phylogenic groups from calf forage fed gut were four similar portions of Firmicutes (23.46%), Actinobacteria (24.58%), Bacteroidetes (25.01%), and Proteobacteria (31.08%). Despite the bacterial community structures were depended on feeding nutrient sources, the identified bacterial strains were revealed unique species of BSF gut unlike other intestinal microflora. Here, we analyzed and discussed the bacterial community structures, possible unique bacterial flora of BSF larval gut, and organic compounds degrading enzymes producing bacterial strains.