title: Engineering nonphosphorylative metabolism to synthesize mesaconate from lignocellulosic sugars in Escherichia coli.
abstract: Dicarboxylic acids are attractive biosynthetic targets due to their broad applications and their challenging manufacturing process from fossil fuel feedstock. Mesaconate is a branched, unsaturated dicarboxylic acid that can be used as a co-monomer to produce hydrogels and fire-retardant materials. In this study, we engineered nonphosphorylative metabolism to produce mesaconate from d-xylose and l-arabinose. This nonphosphorylative metabolism is orthogonal to the intrinsic pentose metabolism in Escherichia coli and has fewer enzymatic steps and a higher theoretical yield to TCA cycle intermediates than the pentose phosphate pathway. Here mesaconate production was enabled from the d-xylose pathway and the l-arabinose pathway. To enhance the transportation of d-xylose and l-arabinose, pentose transporters were examined. We identified the pentose/proton symporter, AraE, as the most effective transporter for both d-xylose and l-arabinose in mesaconate production process. Further production optimization was achieved by operon screening and metabolic engineering. These efforts led to the engineered strains that produced 12.5g/l and 13.2g/l mesaconate after 48h from 20g/l of d-xylose and l-arabinose, respectively. Finally, the engineered strain overexpressing both l-arabinose and d-xylose operons produced 14.7g/l mesaconate from a 1:1 d-xylose and l-arabinose mixture with a yield of 85% of the theoretical maximum. (0.87g/g). This work demonstrates an effective system that converts pentoses into a value-added chemical, mesaconate, with promising titer, rate, and yield.
authors.affiliation: Department of Chemical Engineering and Materials Science, University of Minnesota, Minneapolis, MN 55455, USA; Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin 300308, China; College of Life Science, Shanxi Normal University, Linfen 041004, China.
authors.forename: Wenqin
authors.initials: W
authors.lastname: Bai
authors.affiliation: Department of Chemical Engineering and Materials Science, University of Minnesota, Minneapolis, MN 55455, USA.
authors.forename: Yi-Shu
authors.initials: YS
authors.lastname: Tai
authors.affiliation: Department of Chemical Engineering and Materials Science, University of Minnesota, Minneapolis, MN 55455, USA.
authors.forename: Jingyu
authors.initials: J
authors.lastname: Wang
authors.affiliation: Department of Chemical Engineering and Materials Science, University of Minnesota, Minneapolis, MN 55455, USA.
authors.forename: Jilong
authors.initials: J
authors.lastname: Wang
authors.affiliation: Department of Chemical Engineering and Materials Science, University of Minnesota, Minneapolis, MN 55455, USA.
authors.forename: Pooja
authors.initials: P
authors.lastname: Jambunathan
authors.affiliation: Department of Chemical Engineering and Materials Science, University of Minnesota, Minneapolis, MN 55455, USA.
authors.forename: Kevin J
authors.initials: KJ
authors.lastname: Fox
authors.affiliation: Department of Chemical Engineering and Materials Science, University of Minnesota, Minneapolis, MN 55455, USA. Electronic address: kzhang@umn.edu.
authors.forename: Kechun
authors.initials: K
authors.lastname: Zhang
mesh_terms: D001089:Arabinose / Q000378:metabolism; D053898:Biosynthetic Pathways / Q000235:genetics; D004926:Escherichia coli / Q000502:physiology*; D029968:Escherichia coli Proteins / Q000235:genetics* / Q000378:metabolism; D005650:Fumarates / Q000302:isolation & purification / Q000378:metabolism*; D024861:Genetic Enhancement / Q000379:methods; D008031:Lignin / Q000378:metabolism; D008298:Maleates / Q000302:isolation & purification / Q000378:metabolism*; D060847:Metabolic Engineering / Q000379:methods*; D053858:Metabolic Networks and Pathways / Q000235:genetics*; D010429:Pentoses / Q000378:metabolism*; D010766:Phosphorylation / Q000235:genetics; D014994:Xylose / Q000378:metabolism
chemical_list: D029968:Escherichia coli Proteins; D005650:Fumarates; D008298:Maleates; D010429:Pentoses; C073341:citraconic acid; C036909:lignocellulose; D008031:Lignin; D014994:Xylose; D001089:Arabinose
keywords: Dicarboxylic acid; Escherichia coli; Mesaconate; Nonphosphorylative metabolism; Pentose