Performance analyses of a neutralizing agent combination strategy for the production of succinic acid by <Emphasis Type="Italic">Actinobacillus succinogenes</Emphasis> ATCC 55618

A neutralizing agent combination strategy was developed to enhance the succinic acid production by Actinobacillus succinogenes ATCC 55618. First, a maximal succinic acid production of 48.2 g/L was obtained at a culture pH of 7.5. Second, NaOH and KOH were screened to identify the optimal neutralizing agent for pH control. However, the production of succinic acid did not increase, and severe cell flocculation was observed due to a high concentration of metal ions when only one neutralizing agent was used to control pH. Finally, a neutralizing agent combination strategy was developed with a supply of neutralizing agents with OH⁻ and carbonate. The cell flocculation was eliminated, and a maximum succinic acid production of 59.2 g/L was obtained with 5 M NaOH and 40 g/L of MgCO₃; this production was 27.9% higher than that obtained with NaOH alone. The results obtained in this study may be useful for the large-scale industrial production of succinic acid.