Flux balance analysis of glucose degradation by anaerobic digestion in negative pressure

Abstract Flux balance analysis (FBA) has been widely used for detecting internal fluxes of bacteria. In this study, FBA was applied to estimate metabolic phenotype in glucose fermentation under negative pressure. Result revealed that ethanol, propionic acid, and butyric acid were converted to acetate by lowering headspace pressure (HP) of fermenter with the conversion rate of 0.091, 0.014, and 0.017 mol-acetate/mol-glucose respectively In addition, these three substances were simultaneously converted into H2 with the conversion rate of 0.258 mol-H2/mol-glucose. A total of 30% acetate and 26% H2 production increase were observed under condition of 0.6 atm HP fermentation. Furthermore, 30% accumulated hydrogen was consumed in the formation of propanol and valeric acid.