Modulation of lipidomic and proteomic profile by diet composition in black soldier fly

Within the framework of a circular bioeconomy, the valorisation of organic waste streams into high-value biomolecules represents a sustainable strategy to reduce environmental burdens while generating renewable resources. In this context, the black soldier fly (Hermetia illucens, BSF) has emerged as an effective biocatalyst for converting the organic fraction of municipal solid waste (OFMSW) into high-value biomolecules. We investigated how two surrogate OFMSW substrates (s-OFMSW and a nutrient-modified variant) and two developmental stages (last-instar larvae and 4-day-old pupae) shape BSF biomass composition. Lipidomic and proteomic profiles were characterised and analysed by two-way ANOVA, clustering, pathway enrichment, and cross-omics correlation. Protein isolates showed high purity with stage- and diet-dependent solubility; essential amino acids were comparatively enriched in larvae. The developmental stage was the main driver of lipidomic variation, whereas diet more strongly influenced the proteome, particularly in pupae. Larvae reared on the lipid-rich s-OFMSW accumulated energy-dense lipids (such as triacylglycerols and fatty acids), consistent with metabolic demands preceding metamorphosis. Pupae showed increased fatty acid esters of hydroxy fatty acids and diacylglycerols and uniquely accumulated monoacylglycerols, phosphatidylserines/ethanolamines and acylcarnitines, reflecting lipid mobilisation and membrane remodelling. The modified s-OFMSW promoted the accumulation of structural lipids (sphingomyelins, lysophosphatidylcholines) together with triacylglycerol storage. Lipid pathway enrichment consistently highlighted glycerophospholipid metabolism, and integrative analyses revealed coordinated regulation across proteins and metabolites. Overall, diet composition and developmental stage jointly and predictably modulate BSF lipid and protein landscapes and chitin yields, enabling rational optimisation of rearing strategies to tailor biomass quality for feed, materials, and other biotechnological applications.