Biohydrogen production through active saccharification and photo-fermentation from alfalfa.

Studying biohydrogen production from alfalfa is of practical significance to cleaner production and biomass utilization. The performances of biohydrogen production through active/passive saccharification and photo-fermentation were compared. The effects of initial pH, substrate concentration, and cellulase loading on biohydrogen production from alfalfa by photosynthetic bacteria HAU-M1 were presented. It was found that the maximum hydrogen yield of 55.81 mL/g was achieved at initial pH of 6.90, substrate concentration of 31.23 g/mL, and cellulase loading of 0.13 g/g. Hydrogen yield of active saccharification and photo-fermentation was much higher as compare to passive saccharification and photo-fermentation. Initial pH value showed a more significant influence on photosynthetic bacteria in comparison to cellulase in active saccharification and photo-fermentation biohydrogen production. The low yield of propionic acid suggested that it was an efficient photosynthetic hydrogen production. Photo-fermentation hydrogen production from alfalfa provides a novel path for efficient utilization of alfalfa.