(69d) Bioenergetics of Succinic Acid Production by E.Coli

C4- dicarboxylic acids are potential building blocks for deriving commodity and specialty chemicals from biomass. E.coli strains engineered for succinic acid acids formation are, however, incapable of robust growth in minimal media. To elucidate the causal mechanisms for this observed growth defect, we employed a selection strategy to identify genes that improve growth of NZN111- a succinic acid production strain. Our studies suggest that altered internal redox balance is the primary cause for the growth inhibition of this strain. Using SCALEs, a genome wide approach, we identified a number of genetic changes that can balance the redox inside the cell and restore microaerobic growth of NZN111 in minimal media. Based on this genetic information, we employed genetic as well as process changes to achieve better anaerobic growth and subsequent higher succinic acid production.