High-yield biohydrogen production from non-detoxified sugarcane bagasse: Fermentation strategy and mechanism

Anaerobic digestion, an attractive process for generation of hydrogen, involves complex microbial processes on decomposition of waste biomass. Here, efficient biohydrogen production (277.4 mM (6.2 L-H-2/L)) from non-detoxified sugarcane bagasse (NDSCB) was accomplished through a novel two-stage anaerobic fermentation, which to our knowledge, is the first utilization of NDSCB for biohydrogen fermentation. Interestingly, the hydrogen production of the second stage fermentation (167.8 mM) was significantly higher than that of the first stage fermentation (108.6 mM). Metabolite analysis showed that the metabolic flux had been redirected and Butyrate/Acetate ratio was enhanced in the second stage fermentation. Simulation of the second-stage fermentation condition indicated that acetate and butyrate generated in the first-stage fermentation could significantly enhance the hydrogen production from NDSCB by 51% and 28%, respectively. More interestingly, the stimulatory effect of butyrate was influenced by substrate. The present work provided a comprehensive insight of metabolite on biohydrogen production and an environment-friendly process for lignocellulosic biohydrogen production.