E. coli
Metabolic engineering of E. coli has focused on the production of succinate, 1,2-propanediol, acetoin and esters such as isoamyl acetate.
The engineering of cofactors, coenzyme A/acetyl-CoA and NADH has demonstrated the effects that manipulation of availability of these cofactors can have on production of compounds such as ethanol and esters. The extension of this concept to manipulation of NADPH availability is useful for formation of chiral compounds, colored compounds, polyhydroxybutyrate, lycopene, etc.
Studies of the transition between aerobic growth and anaerobic growth have shown the effects of regulatory and metabolic mutants on fluxes through the major carbon catabolic pathways. Other regulatory studies have investigated the acid stress response and used this information to construct pH regulated gene expression vectors.