Succinic acid biosynthesis from cane molasses under low pH by Actinobacillus succinogenes immobilized in luffa sponge matrices.

Highlights • Cane molasses pretreated by UF membrane is preferred for SA biosynthesis. • Sugar ratio in the cane molasses has little effect on SA production. • A low pH of 6.4 is more favorable for SA production with NaOH as neutralizer. • Biotin and pantothenic acid in molasses play an important role on SA production. • SA productivity was improved with cell immobilization in luffa sponge. Abstract Succinic acid (SA) production by Actinobacillus succinogenes 130Z using cane molasses as a low cost carbon source was developed. With molasses pretreated by 150 kDa membrane, the highest SA concentration (45.6 g/L), productivity (1.27 g/L·h) and yield (0.76 g SA/g sugars) were obtained under an optimal pH 6.4, which were increased by 1.04 folds compared to those with model sugar mixture due to the effect of vitamins in molasses. Meanwhile, the ratio of sugars in the cane molasses had little effect on SA production. To further enhance SA productivity, the cells were immobilized in luffa sponge matrices (LSM), and repeated batch cultures were carried out for 5 cycles, demonstrating a stable and reliable long-term performance. Compared with the batch culture, the SA productivity enhanced by 49.6% in the LSM system with repeated batch culture. These results suggest that the cell immobilization approach is promising for industrial applications. [ABSTRACT FROM AUTHOR]