In dark fermentation, substrate is converted to hydrogen
and organic acids, but the production of organic acids can
inhibit the dark fermentative bacteria resulting in low
hydrogen production [6]. In photo fermentation, the organic
acids from dark fermentation effluent (DFE) can assimilate by
photosynthetic bacteria [7,8]. From this point, combination of
two-stage processes could achieve high hydrogen production
and increase conversion efficiency [9]. Recently, waste materials
such as potato starch [10], beet molasses [11], cheese
whey wastewater [12], and corncob [13] can successfully be used as substrate for two-stage processes of hydrogen production
as well as waste minimization.