Tunable production of succinic acid at elevated pressures of CO in a high pressure gas fermentation reactor.

Production of bio-based alternative of succinic acid (SA) has been growing due to the awareness on environmental advantages it offers, such as CO sequestration. Current study focuses on evaluating the impact of different CO partial pressures (0.6, 0.8, 1, 2 bar) on SA production and yield as well as on other parameters like acids profile and CO fixation rate in Citrobacter amalonaticus. Increasing partial pressure to 2 bar enhanced SA production and maximum of 14.86 gL was achieved with a productivity of 0.36 gLh and yield of 52.10%. Varying partial pressures depicted significant influence on total acids profile, where at lower pressures (0.6 bar) lactic (5.6 gL) and acetic acids (4.1 gL) became dominant products, while concentration of SA was 2.07 gL, by the end of cycle. The desirable effect of moderately elevated pressures for converting CO to platform chemicals can be a potential strategy in overcoming current challenges related to CO abatement.