International Journal of Hydrogen Energy, Vol.39, No.14, 7486-7495, 2014
Behavior of acidogenesis during biohydrogen production with formate and glucose as carbon source: Substrate associated dehydrogenase expression
Experiments were designed to enumerate variation in biohydrogen (H-2) production pattern with formate and glucose as carbon source under acidogenic mixed microenvironment. High H-2 production was observed with glucose (180 ml) when compared to formate (152 ml). The process was validated with modified Gompertz model (R-2 = 0.98). Substrate degradation also showed higher removal of glucose (xi(COD), 82%) compared to formate (xi(COD), 53%). Nevertheless, specific H-2 yield of formate (6.6 mol H-2/kg CODR) obtained was comparatively higher than glucose (5 mol H-2/kg CODR). Variation in H-2 production was manifested by change in fatty acid composition and substrate degradation pattern. Acetate was obtained as a major metabolic intermediate from the degradation of glucose and a shift in the biochemical pathway towards formation of butyrate occurred after maximum substrate degradation. The role of substrate-dependent dehydrogenase activity was deciphered during H-2 production and was evidenced with bio-electrochemical analysis. Copyright (C) 2014, Hydrogen Energy Publications, LLC. Published by Elsevier Ltd. All rights reserved.