title: Simultaneous utilization of D-cellobiose, D-glucose, and D-xylose by recombinant Corynebacterium glutamicum under oxygen-deprived conditions.
abstract: 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 bglF317A 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 bglF317A-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.
authors.affiliation: Research Institute of Innovative Technology for the Earth (RITE), 9-2, Kizugawadai, Kizugawa-shi, Kyoto, 619-0292, Japan.
authors.forename: Miho
authors.initials: M
authors.lastname: Sasaki
authors.forename: Toru
authors.initials: T
authors.lastname: Jojima
authors.forename: Masayuki
authors.initials: M
authors.lastname: Inui
authors.forename: Hideaki
authors.initials: H
authors.lastname: Yukawa
mesh_terms: D019747:Aldose-Ketose Isomerases / Q000235:genetics / Q000378:metabolism; D002475:Cellobiose / Q000378:metabolism*; D048230:Corynebacterium glutamicum / Q000235:genetics / Q000378:metabolism*; D029968:Escherichia coli Proteins / Q000235:genetics / Q000378:metabolism; D005818:Genetic Engineering; D005947:Glucose / Q000378:metabolism*; D010100:Oxygen / Q000378:metabolism*; D017853:Phosphotransferases (Alcohol Group Acceptor) / Q000235:genetics / Q000378:metabolism; D014994:Xylose / Q000378:metabolism*
chemical_list: D029968:Escherichia coli Proteins; D002475:Cellobiose; D014994:Xylose; D017853:Phosphotransferases (Alcohol Group Acceptor); C032700:xylulokinase; D019747:Aldose-Ketose Isomerases; C023298:xylose isomerase; D005947:Glucose; D010100:Oxygen