Simultaneous utilization of D-cellobiose, D-glucose, and D-xylose by recombinant Corynebacterium glutamicum under oxygen-deprived conditions.
Appl. Microbiol. Biotechnol. 81: 691-699. 2008.
M. Sasaki, T. Jojima, M. Inui and H. Yukawa.

Corynebacterium glutamicum R was metabolically engineered to broaden its sugar utilization range to D: -xylose and D: -cellobiose contained in lignocellulose hydrolysates. The resultant recombinants expressed Escherichia coli xylA and xylB genes, encoding D: -xylose isomerase and xylulokinase, respectively, for D: -xylose utilization and expressed C. glutamicum R bglF ( 317A ) and bglA genes, encoding phosphoenolpyruvate:carbohydrate phosphotransferase system (PTS) beta-glucoside-specific enzyme IIBCA component and phospho-beta-glucosidase, respectively, for D: -cellobiose utilization. The genes were fused to the non-essential genomic regions distributed around the C. glutamicum R chromosome and were under the control of their respective constitutive promoter trc and tac that permitted their expression even in the presence of D: -glucose. The enzyme activities of resulting recombinants increased with the increase in the number of respective integrated genes. Maximal sugar utilization was realized with strain X5C1 harboring five xylA-xylB clusters and one bglF ( 317A )-bglA cluster. In both D: -cellobiose and D: -xylose utilization, the sugar consumption rates by genomic DNA-integrated strain were faster than those by plasmid-bearing strain, respectively. In mineral medium containing 40 g l(-1) D: -glucose, 20 g l(-1) D: -xylose, and 10 g l(-1) D: -cellobiose, strain X5C1 simultaneously and completely consumed these sugars within 12 h and produced predominantly lactic and succinic acids under growth-arrested conditions.