| In this thesis work I examined the effect of manipulating the oxidationreduction potential (ORP) of the extracellular environment as a means of increasing succinate production. The feeding strategy employed in this study involved replacing the CO2 in the reactor with air after 24, 27 and 36 hours of anaerobic growth. Air acts as electron acceptor, due to oxygen, which helps to consume the excess NADH that is associated with E. coli AFP111 fermentations in minimal media. Dual-phase fermentations with E. coli AFP111 found that when the new feeding strategy was used, E. coli AFP111 had increased growth and succinate productivity. Compared to fermentations of AFP111 run without the feeding strategy, growth was increased from 1.05 to 1.57 (OD600) and productivity increased from 0.10 g/L/hr to 0.14 g/L/hr when the feeding strategy was used. |
