Tunable production of succinic acid at elevated pressures of CO2 in a high pressure gas fermentation reactor

Abstract

Production of bio-based alternative of succinic acid (SA) has been growing due to the awareness on environmental advantages it offers, such as CO₂ sequestration. Current study focuses on evaluating the impact of different CO₂ partial pressures (0.6, 0.8, 1, 2 bar) on SA production and yield as well as on other parameters like acids profile and CO₂ fixation rate in Citrobacter amalonaticus. Increasing partial pressure to 2 bar enhanced SA production and maximum of 14.86 gL^-1 was achieved with a productivity of 0.36 gL^-1h^-1 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^-1) and acetic acids (4.1 gL^-1) became dominant products, while concentration of SA was 2.07 gL^-1, by the end of cycle. The desirable effect of moderately elevated pressures for converting CO₂ to platform chemicals can be a potential strategy in overcoming current challenges related to CO₂ abatement.

Keywords: Bioeconomy; CO(2) fixation; Dicarboxylic acid; Microbial synthesis; Platform chemicals.