Vliegen, schimmels en microbiële functies: de rol van micro-organismen bij de productie van de zwarte soldatenvlieg (Hermetia illucens) en bij het verbeteren van het larvale nutritioneel profiel

The Black soldier fly (Hermetia illucens L., Diptera: Stratiomyidae) is an insect produced on an industrial scale, mainly as a feed ingredient. The nutritional profile of black soldier fly larvae (BSFL) make them a suitable, alternative protein source in various animal feeds, however their fatty acid profile lacks several polyunsaturated fatty acids, specifically ω-3 and ω-6 fatty acids, which limits the application of BSFL as an ingredient in fish feed. The nutritional profile of the larvae is influenced by their diet, and the BSFL can be reared on a range of substrates, including various waste streams such as restaurant waste, agricultural side-products and animal manure, reducing waste through the bioconversion of these waste streams into valuable insect biomass. However, the role of the insect's microbiome during the conversion of these waste streams and potential functions they have during BSFL development, remain poorly understood. This PhD project focusses on two aspects involving microorganisms and the BSFL. First, this project investigates the potential to improve the fatty acid profile of the BSFL through substrate manipulation, using the oil-producing fungus Mortierella alpina as a cheap and sustainable source of ω-3 and ω-6 fatty acids. Here, nutritionally-poor agricultural sidestreams will be fermented with this microorganism and the fermented substrates will be developed into a nutritional BSFL feed. In the second part of the PhD, advance DNA sequencing techniques will be employed to identify the BSFL microbiota, a collection of bacteria, fungi and viruses that inhabit the larvae, in order to discover potential metabolic and protective microbial functions they provide for their host, potentially aiding the BSFL to grown on a wide variety of substrates. Identification of these microorganisms and their potential beneficial functions for the BSFL can further our understanding of the role of the insect microbiome and potentially identify bacterial- and/or fungal species suited as probiotics.