Effects of VFAs concentration on bio-hydrogen production with clostridium bifermentans 3AT-ma

This study evaluated that the effects of concentration of VFAs (volatile fatty acids), such as acetate and butyrate, on bio-hydrogen production from high salinity organic substrate with halophilic hydrogenproducing bacteria of Clostridium bifermentans 3AT-ma. Glucose medium was used a substrate. Supplementary acetate and butyrate concentrations were ranged 0 to 500 mM and 0 to 250 mM, respectively. The increased concentration of acetate and butyrate significantly influenced to hydrogen production. At the initial condition, VFAs concentration of 0 g/L, maximum hydrogen was produced. The hydrogen production was decreased as increasing dosage of acetate and butyrate. The inhibitory effect by adding acetate on fermentative hydrogen production was less significant compared to that by butyrate. A modified Gompertz equation could be successfully described the cumulative H2 production at different VFAs concentrations. In addition, the inhibition by adding VFAs on hydrogen production was described well by a non-competitive inhibition model.