Black soldier fly (hermetia illucens) as a source of new biologically active substances of protein nature

Abstract

The black soldier fly (Hermetia illucens) is a promising organism for the bioconversion of organic waste. The symbiotic microflora of the larval gastrointestinal tract plays a key role in this process, which can also serve as a source of biologically active compounds, including antimicrobial peptides (AMP). The purpose of this work was to search for producers of biologically active substances among the saprophytic microbiota of black soldier fly (BSF) frass larvae of H. illucens, as well as to evaluate the antimicrobial activity of protein lyophilizates obtained from insect tissues. The study involved the cultivation of larvae on five different substrates, microbiological analysis of BSF frass flushes, and DNA isolation followed by sequencing of the 16S rRNA gene to identify bacterial isolates. In parallel, protein extracts were obtained from larval biomass by alkaline extraction followed by purification by dialysis and their antimicrobial activity against Escherichia coli and Bacillus subtilis was evaluated.

As a result, the strains Heyndrickxia sporothermodurans and Heyndrickxia oleronia were identified, which, according to phylogenetic analysis, are potential producers of AMP (amylocyclin, fengycin). It was shown that protein fractions with a molecular weight above 20 kDa have lytic activity against test cultures, while fractions less than 20 kDa showed no pronounced effect. The data obtained indicate the prospects of using both the microbiota of frass and the larvae of the black soldier fly to search for new antimicrobial agents that can be used in medicine and the food industry as an alternative to conventional antibiotics and chemical preservatives.