title: Biosynthesis of ethylene glycol in Escherichia coli.
abstract: Ethylene glycol (EG) is an important platform chemical with steadily expanding global demand. Its commercial production is currently limited to fossil resources; no biosynthesis route has been delineated. Herein, a biosynthesis route for EG production from D-xylose is reported. This route consists of four steps: D-xylose → D-xylonate → 2-dehydro-3-deoxy-D-pentonate → glycoaldehyde → EG. Respective enzymes, D-xylose dehydrogenase, D-xylonate dehydratase, 2-dehydro-3-deoxy-D-pentonate aldolase, and glycoaldehyde reductase, were assembled. The route was implemented in a metabolically engineered Escherichia coli, in which the D-xylose → D-xylulose reaction was prevented by disrupting the D-xylose isomerase gene. The most efficient construct produced 11.7 g L(-1) of EG from 40.0 g L(-1) of D-xylose. Glycolate is a carbon-competing by-product during EG production in E. coli; blockage of glycoaldehyde → glycolate reaction was also performed by disrupting the gene encoding aldehyde dehydrogenase, but from this approach, EG productivity was not improved but rather led to D-xylonate accumulation. To channel more carbon flux towards EG than the glycolate pathway, further systematic metabolic engineering and fermentation optimization studies are still required to improve EG productivity.
authors.affiliation: Energy and Environment Fusion Technology Center (E2FTC), Department of Energy Science and Technology (DEST), Myongji University, Room 8807, Engineering College Building 2, San 38-2, Namdong, Cheoin-gu, Yongin, Gyeonggi 449-728, South Korea. huaiwei.liu@gmail.com
authors.forename: Huaiwei
authors.initials: H
authors.lastname: Liu
authors.forename: Kristine Rose M
authors.initials: KR
authors.lastname: Ramos
authors.forename: Kris Niño G
authors.initials: KN
authors.lastname: Valdehuesa
authors.forename: Grace M
authors.initials: GM
authors.lastname: Nisola
authors.forename: Won-Keun
authors.initials: WK
authors.lastname: Lee
authors.forename: Wook-Jin
authors.initials: WJ
authors.lastname: Chung
mesh_terms: D053898:Biosynthetic Pathways / Q000235:genetics*; D004926:Escherichia coli / Q000235:genetics* / Q000378:metabolism*; D019855:Ethylene Glycol / Q000378:metabolism*; D060847:Metabolic Engineering / Q000379:methods; D014994:Xylose / Q000378:metabolism
chemical_list: D014994:Xylose; D019855:Ethylene Glycol