title: Elucidating acetogenic H2 consumption in dark fermentation using flux balance analysis.
abstract: In this study, a flux balance analysis (FBA) was adopted to estimate the activity of acetogenic H2-consuming reaction. Experimental data at different substrate concentrations of 10, 20, and 30 g COD/L showing the lowest, medium, and highest H2 yields, respectively, were used in the FBA to calculate the fluxes. It was interesting to note that the hydrogenase activity based on R12 (2Fd(+)+2H(+)→2Fd(2+)+H2, ferredoxin (Fd)) flux was most active at 10 g COD/L. The flux of R17 (4H2+2CO2→CH3COOH), a mechanism for reutilizing produced H2, increased in steps of 0.030, 0.119, and 0.467 as the substrate concentration decreased. Contradictory to our general understanding, acetate production found to have a negligible or even negative effect on the final H2 yield in dark fermentation.
authors: Department of Civil and Environmental Engineering, University of Windsor, 401 Sunset Ave., Essex Hall, Windsor, Ontario N9B 3P4, Canada.
authors: Jerald A
authors: JA
authors: Lalman
authors: Department of Civil and Environmental Engineering, University of Windsor, 401 Sunset Ave., Essex Hall, Windsor, Ontario N9B 3P4, Canada; Great Lakes Institute of Environmental Research, University of Windsor, 401 Sunset Ave., Essex Hall, Windsor, Ontario N9B 3P4, Canada.
authors: Subba Rao
authors: SR
authors: Chaganti
authors: Department of Civil and Environmental Engineering, University of Windsor, 401 Sunset Ave., Essex Hall, Windsor, Ontario N9B 3P4, Canada.
authors: Chungman
authors: C
authors: Moon
authors: Clean Fuel Department, Korea Institute of Energy Research, 102 Gajeong-ro, Yuseong-gu, Daejeon 305-343, Republic of Korea. Electronic address: dhkim77@kier.re.kr.
authors: Dong-Hoon
authors: DH
authors: Kim
mesh_terms: D000085:Acetates / Q000737:chemistry; D001407:Bacillus / Q000378:metabolism; D057919:Biological Oxygen Demand Analysis; D019149:Bioreactors; D003013:Clostridium / Q000378:metabolism; D003624:Darkness; D005285:Fermentation; D005288:Ferredoxins / Q000737:chemistry; D005947:Glucose / Q000737:chemistry; D006859:Hydrogen / Q000032:analysis* / Q000737:chemistry; D006863:Hydrogen-Ion Concentration; D006864:Hydrogenase / Q000737:chemistry; D007778:Lactobacillus / Q000378:metabolism; D008956:Models, Chemical; D013816:Thermodynamics
chemical_list: D000085:Acetates; D005288:Ferredoxins; D006859:Hydrogen; D006864:Hydrogenase; D005947:Glucose
keywords: Acetate; Acetogenic H(2) consumption; Flux balance analysis; Hydrogen fermentation