A fibrous bed bioreactor to improve the productivity of succinic acid by Actinobacillus succinogenes

Abstract

Background: Succinic acid is one of the most important biorefinery platform chemicals. The fibrous-bed bioreactor (FBB), comprising spiral cotton fiber packed in a modified bioreactor, is effective for anaerobic cell-immobilized fermentation. In this study, fermentation production of succinic acid by Actinobacillus succinogenes using a FBB was investigated. Results: The effect of different initial glucose concentrations on succinic acid production in batch fermentation in a FBB was examined, which indicated that the optimal initial glucose concentration was 55 g L-1. In 10 batches of repeated-batch fermentation, the average succinic acid productivity, concentration, and yield were 3.61 g L-1 h-1, 39.0 g L-1, and 0.85 g g-1, respectively. A maximum succinic acid concentration of 98.7 g L-1 was reached in fed-batch fermentation comprising four batches of fermentation, with a succinic acid yield of 0.89 g g-1 and productivity of 2.77 g L-1 h-1. Conclusion: Succinic acid fermentation by A. succinogenes in a FBB was successfully performed to enhance succinic acid productivity. And also, high succinic acid concentration with high reactor productivity and yield were simultaneously achieved in the FBB with fed-batch fermentation.