title: Engineering Escherichia coli for efficient cellobiose utilization.
abstract: Escherichia coli normally cannot utilize the β-glucoside sugar cellobiose as a carbon and energy source unless a stringent selection pressure for survival is present. The cellobiose-utilization phenotype can be conferred by mutations in the two cryptic operons, chb and asc. In this study, the cellobiose-utilization phenotype was conferred to E. coli by replacing the cryptic promoters of these endogenous operons with a constitutive promoter. Evolutionary adaptation of the engineered strain CP12CHBASC by repeated subculture in cellobiose-containing minimal medium led to an increase in the rate of cellobiose uptake and cell growth on cellobiose. An efficient cellobiose-metabolizing E. coli strain would be of great importance over glucose-metabolizing E. coli for a simultaneous saccharification and fermentation process, as the cost of the process would be reduced by eliminating one of the three enzymes needed to hydrolyze cellulose into simple sugars.
authors.affiliation: School of Nano-Bioscience and Chemical Engineering, Ulsan National Institute of Science and Technology, Republic of Korea.
authors.forename: Parisutham
authors.initials: P
authors.lastname: Vinuselvi
authors.forename: Sung Kuk
authors.initials: SK
authors.lastname: Lee
mesh_terms: D002244:Carbon / Q000378:metabolism; D002475:Cellobiose / Q000378:metabolism*; D003470:Culture Media / Q000737:chemistry; D004734:Energy Metabolism; D004926:Escherichia coli / Q000235:genetics* / Q000254:growth & development / Q000378:metabolism*; D015964:Gene Expression Regulation, Bacterial; D005818:Genetic Engineering; D053858:Metabolic Networks and Pathways / Q000235:genetics*; D009876:Operon; D030781:Organisms, Genetically Modified / Q000235:genetics / Q000378:metabolism; D011401:Promoter Regions, Genetic
chemical_list: D003470:Culture Media; D002475:Cellobiose; D002244:Carbon