Fermentative production of succinic acid from straw hydrolysate by Actinobacillus succinogenes

In this work, straw hydrolysates were used to produce succinic acid by Actinobacillus succinogenes CGMCC1593 for the first time. Results indicated that both glucose and xylose in the straw hydrolysates were utilized in succinic acid production, and the hydrolysates of corn straw was better than that of rice or wheat straw in anaerobic fermentation of succinic acid. However, cell growth and succinic acid production were inhibited when the initial concentration of sugar, which was from corn straw hydrolysate (CSH), was higher than 60 g l−1. In batch fermentation, 45.5 g l−1 succinic acid concentration and 80.7% yield were attained after 48 h incubation with 58 g l−1 of initial sugar from corn straw hydrolysate in a 5-l stirred bioreactor. While in fed-batch fermentation, concentration of succinic acid achieved 53.2 g l−1 at a rate of 1.21 g l−1 h−1 after 44 h of fermentation. Our work suggested that corn straw could be utilized for the economical production of succinic acid by A. succinogenes.