Dissolved CO2 profile in bio-succinic acid production from sugars-rich industrial waste

Abstract

The inorganic carbon source (CO2) availability to the microorganisms has a key role in the succinic acid (SA) fermentation process. This study aims to investigate the behavior of the inorganic carbon source for SA production and underline the importance of CO2 in the fermentation process. The effect of pressure was investigated for CO2 availability and its overall impact on the fermentation process. Results obtained demonstrated a significant effect of pressure on yield, productivity and CO2 fixation rate. Industrial waste, rich in maltose, glucose, and sucrose, was used as feedstock combined with a gas mixture of CH4 and CO2, which simulated biogas composition. A final titer for succinic acid of 25.5 ± 2.4 g/L was detected at a headspace gas pressure of 1.4 atm. The yield raised from 0.48 g/g sugars to 0.64 and 0.65 g/g sugars when 1.4 and 1.6 atm pressure was applied, respectively. Overall, this study represents one of the first attempts to explore CO2 availability during succinic acid production, using biogas as a CO2 source and sugars-rich industrial waste as feedstock.