Valorization of organic waste through black soldier fly: On the way of a real circular bioeconomy process

Abstract

The transition from a linear to a circular production system involves transforming waste into valuable resources. Insect-mediated bioconversion, particularly using black soldier fly (BSF) larvae, can offer a promising opportunity to convert the organic fraction of municipal solid waste (OFMSW) into protein-rich biomass. However, current regulatory restrictions do not allow the use of this substrate to obtain insect proteins for animal feed, prompting the exploration of other applications, such as the production of bioplastics. Here, we explored at laboratory scale an innovative and integrated circular supply chain which aims to valorize the OFMSW through BSF larvae for the production of biobased materials with high technological value. BSF larvae reared on this organic waste showed excellent growth performance and bioconversion rate of the substrate. The use of well-suited extraction methods allowed the isolation of high-purity lipids, proteins, and chitin fractions, which are building blocks to produce biobased materials. In particular, the protein fraction was used to develop biodegradable plastic films which showed potential for replacing traditional petroleum-based materials, with the possibility to be fully recycled back to amino acids. Socioeconomic analysis highlighted values generated along the entire supply chain, and life cycle assessment pointed out that lipid extraction was the most challenging step: implementation of more sustainable methods is thus needed to reduce the overall environmental impact of the proposed chain. In conclusion, this study represents a proof of concept gathering evidence to support the feasibility of an alternative supply chain that can promote circular economy while valorising organic waste.