Theoretically, maximum hydrogen yield achieved
when acetate-related pathways are the main routes for H2 production that yielded 4 mol H2/ mol glucose. Minimal
ethanol and propionate generated from the hydrogen consuming pathway were detected. Negligible amount of VFA
detected in the methane fermentation stage after 336 h fermentation indicated that VFA produced in the hydrogen
stage was efficiently converted to methane in the second stage.