title: Simultaneous utilization of glucose and xylose via novel mechanisms in engineered Escherichia coli.
abstract: After glucose, xylose is the most abundant sugar in lignocellulosic carbon sources. However, wild-type Escherichia coli is unable to simultaneously utilize both sugars due to carbon catabolite repression (CCR). In this paper, we describe GX50, an engineered strain capable of utilizing glucose and xylose simultaneously. This strain was obtained by evolving a mutant from which araC has been deleted, and in which genes required for pentose metabolism are constitutively expressed. The strain acquired four additional mutations during adaptive evolution, including intergenic mutations in the 5'-flanking region of xylA and pyrE, and missense mutations in araE (S91I) and ybjG (D99G). In contrast to wild type E. coli, GX50 rapidly converts xylose to xylitol even if glucose is available. Notably, the strain grows well when cultured on glucose, unlike some well-known CCR-insensitive mutants defective in the glucose phosphotransferase system. Our work will advance efforts to design a metabolically efficient platform strain for potential use in producing chemicals from lignocellulose.
authors.affiliation: School of Energy and Chemical Engineering, Ulsan National Institute of Science and Technology (UNIST), Ulsan 689-798, Republic of Korea.
authors.forename: Suk Min
authors.initials: SM
authors.lastname: Kim
authors.affiliation: School of Life Sciences, Ulsan National Institute of Science and Technology (UNIST), Ulsan 689-798, Republic of Korea.
authors.forename: Bae Young
authors.initials: BY
authors.lastname: Choi
authors.affiliation: School of Energy and Chemical Engineering, Ulsan National Institute of Science and Technology (UNIST), Ulsan 689-798, Republic of Korea.
authors.forename: Young Shin
authors.initials: YS
authors.lastname: Ryu
authors.affiliation: School of Life Sciences, Ulsan National Institute of Science and Technology (UNIST), Ulsan 689-798, Republic of Korea.
authors.forename: Sung Hun
authors.initials: SH
authors.lastname: Jung
authors.affiliation: School of Life Sciences, Ulsan National Institute of Science and Technology (UNIST), Ulsan 689-798, Republic of Korea.
authors.forename: Jung Min
authors.initials: JM
authors.lastname: Park
authors.affiliation: School of Life Sciences, Ulsan National Institute of Science and Technology (UNIST), Ulsan 689-798, Republic of Korea.
authors.forename: Goo-Hee
authors.initials: GH
authors.lastname: Kim
authors.affiliation: School of Energy and Chemical Engineering, Ulsan National Institute of Science and Technology (UNIST), Ulsan 689-798, Republic of Korea; School of Life Sciences, Ulsan National Institute of Science and Technology (UNIST), Ulsan 689-798, Republic of Korea. Electronic address: sklee@unist.ac.kr.
authors.forename: Sung Kuk
authors.initials: SK
authors.lastname: Lee
mesh_terms: D004926:Escherichia coli / Q000235:genetics / Q000378:metabolism; D029968:Escherichia coli Proteins / Q000235:genetics* / Q000378:metabolism; D017353:Gene Deletion; D005947:Glucose / Q000235:genetics / Q000378:metabolism*; D060847:Metabolic Engineering / Q000379:methods*; D014994:Xylose / Q000235:genetics / Q000378:metabolism*
chemical_list: D029968:Escherichia coli Proteins; D014994:Xylose; D005947:Glucose
keywords: Escherichia coli; Glucose; Lignocellulose; Metabolic engineering; Xylose