Enhanced biohydrogen production from sugarcane molasses by adding Ginkgo biloba leaves

Low H-2 yield from biomass impedes the industrial application of biohydrogen production. To improve H-2 yield, the effect of Ginkgo biloba leaf (GL) on H-2 production was investigated in this study. In batch fermentation with sugarcane molasses (SM), the addition of GL improved H-2 yield by 28.03%. SM medium was optimized with response surface methodology (RSM) to determine the best concentrations of GL, SM, and an inexpensive nitrogen source-corn steep liquor (CSL). A maximum yield of 1.58 mol-H-2/mol-hexose from SM was obtained when GL, CSL and SM hexose were 2.31 g/L, 2.28 g/L and 10 g/L, respectively. As observed with metabolic flux analysis, GL enhanced H-2 conversion from SM via altering the metabolic flux distribution of E. harbinense from ethanol pathway towards acetate pathway. This study demonstrated the promotion effect of GL on H-2 production from SM, raising a novel method for enhanced biohydrogen production in large scales.