Potato peel waste for fermentative biohydrogen production using different pretreated culture

[Display omitted] •Potato peel waste was firstly used as feedstock for bioH2 production by mixed culture.•Four effective methods were compared for enriching H2-producing inoculum.•A high H2 yield of 71.0 mL/g-VSadded was achieved by aeration enriched inoculum.•Bacterial community structure was analyzed to reveal the H2-producing mechanism.•The enrichment of Clostridium sp. was responsible for the efficient H2 production. How to manage potato peel waste sustainably has been an issue faced by the potato industry. This work explored the feasibility of potato peel waste for biohydrogen production via dark fermentation, and investigated the effects of various inoculum enrichment methods (acid, aeration, heat-shock and base) on the process efficiency. It was observed that the hydrogen production showed a great variation when using various inoculum enrichment methods, and the aeration enriched inoculum obtained the maximum hydrogen yield of 71.0 mL/g-VSadded and VS removal of 28.9 %. Different enriched cultures also exhibited huge variations in the bacterial community structure and metabolic pathway. The highest abundance of Clostridium sensu stricto fundamentally contributed to the highest process efficiency for the fermenter inoculated with aeration treated culture. This work puts forward a promising strategy for recycling potato peel waste, and fills a gap in the optimal inoculum preparation method for biohydrogen fermentation of potato peel waste.