Strategies of pH control and glucose-fed batch fermentation for production of succinic acid by Actinobacillus succinogenes CGMCC1593

Background: Succinic acid is an important precursor of numerous products, including pharmaceuticals, feed additives, green solvents, and biodegradable polymers. In this work, strategies of pH control and glucose-fed batch fermentation for producing succinic acid using Actinobacillus succinogenes CGMCC1593 were carefully optimized. Results: The production of succinic acid was stable within the pH range 6.0-7.2. Both cell growth and succinic acid production were inhibited by high concentrations of sodium and calcium ions, while there was no significant inhibition by magnesium ions. With an initial glucose concentration of 25 g L^-1, and glucose concentration was maintained between 10 and 15 g L^-1 during the course of fed batch fermentation, succinic acid concentration, productivity and yield were 60.2 g L^-1, 1.3 g L^-1 h^-1 and 75.1%, respectively. Conclusion: Of all the neutralization reagents used for pH control of A. succinogenes CGMCC1593, solid MgCO₃ was the most satisfactory. With increase of initial glucose concentration, the time course showed a longer growth lag period and the maximum biomass declined, while more carbon was diverted to succinate synthesis. The results obtained in this study should be helpful for the design of a highly efficient succinic acid production process.