Substrate inhibition of succinic acid fermentation with Actinobacillus succinogenes NJ113

Anaerobic fermentative production of succinic acid by Actinobacillus succinogenes NJ113 with glucose as the substrate in batch fermentation was studied. Fed-batch fermentation was performed to minimize the inhibition effect of substrate (glucose). In this case, 45.27 g/L succinic acid and productivity of 1.74 g/(L·h) were attained after 26 h incubation with total glucose concentration of 60 g/L using Na₂CO₃ as the pH regulator, with a level less than 10 g/L of glucose concentration. Compared with the batch fermentation, the fermentation period was already shortened by up to 18.75%. The yield of succinic acid and productivity were raised by 5.44% and 31.82% respectively in fed-batch fermentation, and the by-product formic acid decreased and the acetic acid increased in the process.