Metagenomic insights into improving mechanisms of Fe0 nanoparticles on volatile fatty acids production from potato peel waste anaerobic fermentation

[Display omitted] •Potato peel waste (PPW) was used as a potential feedstock for VFAs production.•Fe0 nanoparticles effectively enhanced VFAs production from PPW.•Fe0 nanoparticles promoted the activity of acetate kinase and butyrate kinase.•Fe0 nanoparticles help build a more effective microbial community.•Fe0 nanoparticles up-regulated the genes responsible for VFAs formation. The management of potato peel waste (PPW) has been a challenge faced by the potato industry. This investigation assessed the feasibility of PPW for volatile fatty acids (VFAs) production via anaerobic fermentation, and investigated the impact of Fe0 nanoparticles (Fe0 NPs) supplementation on the VFAs production. It is found that PPW is a potential feedstock for producing VFAs, achieving a yield of 480.4 mg COD/g-vS Meanwhile, the supplementation of Fe0 NPs significantly promoted the VFAs productivity and quality. The higher enrichment of VFAs-producing bacteria, including Clostridium, Proteiniphilum, Fonticella and Pygmaiobacter, contributed to the promotion of the VFAs yield. Furthermore, metagenomic analysis revealed that the encoding genes responsible for carbohydrate metabolism (especially starch), membrane transport, glycolysis and the formation of acetic and butyric acids were remarkably up-regulated,which could be the essential reason for the enhanced metabolic activity and VFAs productivity. This work provides a promising strategy for recycling PPW.