Simultaneous Utilization of Glucose and Xylose for Efficient Succinate Production by Engineered Corynebacterium glutamicum

Pentose utilization is considered as an important segment for lignocellulosic biorefinery due to its abundance in hemicellulosic wastes. In this study, Corynebacterium glutamicum was engineered for efficient succinate production. The xylA and xylB genes from Xanthomonas campestris and the endogenous tkt and tal genes were co-overexpressed, which enabled the strain to produce succinate with a high yield of 0.98 g g ^-1 D-xylose. Expression of araE from Bacillus subtilis further increased succinate production rate by 11%. Finally, the engineered C. glutamicum CGL31 strain could simultaneously and completely consume glucose and xylose and produce 109.5 g L^-1 succinate with a productivity of 6.84 g h ^-1 L ^-1 and a yield of 0.81 g g total sugars ^-1, which suggests it has great potential to efficiently produce succinate from sugar mixtures derived from lignocellulose.

Keywords: Corynebacterium glutamicum, xylose, succinate, transketolase, transaldolase