Olfactory perception of Hermetia illucens: a source of inspiration for the development of new biosensors for the monitoring of agrifood products shelf life

: Insect physiology study at the molecular level and innovative technology implementation allows the development of applications useful to human. An example is the olfactory perception of Hermetia illucens, a saprophagous Diptera that has aroused interest for organic waste bioconversion. Females oviposit on decaying organic matter and larvae feed on it. Through RNAseq, de novo assembly and annotation of larval, male/female adult transcriptomes, we identified H. illucens Odorant Binding Proteins (OBPs) that mediate chemoreception of volatile organic compounds (VOCs) found in decaying substrates. We detected 15 HillOBPs expressed both in larvae and adults. The use of OBPs specific for organic decomposition VOCs are proposed as sensing layers of innovative QuartzCrystal- Microbalances (QCMs) sensors, for monitoring food product preservation and shelf-life, in a new approach to food logistics. Affinities with 57 identified VOCs, emitted by different decomposing substrates colonized by H.illucens larvae, were calculated by molecular docking technique and were confirmed for 4 cloned, expressed and purified HillOBPs immobilized on a gold-layer of QCMs. These experiments provided useful information about biosensor selectivity, as the ability to discriminate ligands of different nature. Four compounds indicative of lipidic decomposition were detected with high affinity in a pool of VOCs, known to be spoilage markers.