Adaptive Evolution Strategy Enhancing Biohydrogen Production Via Anaerobic Mixed Culture

Abstract:

Microbial diversity of mixed culture can result in substantial heterogeneity in physiological and biochemical behaviors such as responses against stress.Such differences can cause "cask effect" during H2 production,and thereby restrict the overall production capacity.In this study,butyric acid stress combined with selective chemical inhibitors was used as the selection pressure to evolve mixed culture in continuous operation.By the adaptive evolution,H2 production capacity via mixed culture can be enhanced by removing the bacteria causing "cask effect" and enriching functional H2-producing bacteria obtaining beneficial evolution.The enhancement was primarily driven by increased acid tolerance,weakened competing pathways,higher activity of hydrogenase and NADH-ferredoxin oxidoreductase(NFOR).