title: Engineering of a Synthetic Metabolic Pathway for the Assimilation of (d)-Xylose into Value-Added Chemicals.
abstract: A synthetic pathway for (d)-xylose assimilation was stoichiometrically evaluated and implemented in Escherichia coli strains. The pathway proceeds via isomerization of (d)-xylose to (d)-xylulose, phosphorylation of (d)-xylulose to obtain (d)-xylulose-1-phosphate (X1P), and aldolytic cleavage of the latter to yield glycolaldehyde and DHAP. Stoichiometric analyses showed that this pathway provides access to ethylene glycol with a theoretical molar yield of 1. Alternatively, both glycolaldehyde and DHAP can be converted to glycolic acid with a theoretical yield that is 20% higher than for the exclusive production of this acid via the glyoxylate shunt. Simultaneous expression of xylulose-1 kinase and X1P aldolase activities, provided by human ketohexokinase-C and human aldolase-B, respectively, restored growth of a (d)-xylulose-5-kinase mutant on xylose. This strain produced ethylene glycol as the major metabolic endproduct. Metabolic engineering provided strains that assimilated the entire C2 fraction into the central metabolism or that produced 4.3 g/L glycolic acid at a molar yield of 0.9 in shake flasks.
authors.affiliation: INSA, UPS, INP, LISBP, Université de Toulouse , 135 Avenue de Rangueil, 31077 Toulouse, France.|INRA, UMR792 Ingénierie des Systèmes Biologiques et des Procédés (LISBP) ,, 31077 Toulouse, France.|UMR5504, CNRS , 31077 Toulouse, France.|TWB , 3 rue des Satellites, Canal Biotech Building 2, 31400 Toulouse, France.
authors.forename: Yvan
authors.initials: Y
authors.lastname: Cam
authors.affiliation: INSA, UPS, INP, LISBP, Université de Toulouse , 135 Avenue de Rangueil, 31077 Toulouse, France.|INRA, UMR792 Ingénierie des Systèmes Biologiques et des Procédés (LISBP) ,, 31077 Toulouse, France.|UMR5504, CNRS , 31077 Toulouse, France.|TWB , 3 rue des Satellites, Canal Biotech Building 2, 31400 Toulouse, France.
authors.forename: Ceren
authors.initials: C
authors.lastname: Alkim
authors.affiliation: INSA, UPS, INP, LISBP, Université de Toulouse , 135 Avenue de Rangueil, 31077 Toulouse, France.|INRA, UMR792 Ingénierie des Systèmes Biologiques et des Procédés (LISBP) ,, 31077 Toulouse, France.|UMR5504, CNRS , 31077 Toulouse, France.|TWB , 3 rue des Satellites, Canal Biotech Building 2, 31400 Toulouse, France.
authors.forename: Debora
authors.initials: D
authors.lastname: Trichez
authors.affiliation: INSA, UPS, INP, LISBP, Université de Toulouse , 135 Avenue de Rangueil, 31077 Toulouse, France.|INRA, UMR792 Ingénierie des Systèmes Biologiques et des Procédés (LISBP) ,, 31077 Toulouse, France.|UMR5504, CNRS , 31077 Toulouse, France.|TWB , 3 rue des Satellites, Canal Biotech Building 2, 31400 Toulouse, France.
authors.forename: Vincent
authors.initials: V
authors.lastname: Trebosc
authors.affiliation: INSA, UPS, INP, LISBP, Université de Toulouse , 135 Avenue de Rangueil, 31077 Toulouse, France.|INRA, UMR792 Ingénierie des Systèmes Biologiques et des Procédés (LISBP) ,, 31077 Toulouse, France.|UMR5504, CNRS , 31077 Toulouse, France.|TWB , 3 rue des Satellites, Canal Biotech Building 2, 31400 Toulouse, France.
authors.forename: Amélie
authors.initials: A
authors.lastname: Vax
authors.affiliation: INSA, UPS, INP, LISBP, Université de Toulouse , 135 Avenue de Rangueil, 31077 Toulouse, France.|Département Génie Mathématiques et Modélisation (GMM) , 135 Avenue de Rangueil, 31077 Toulouse, France.
authors.forename: François
authors.initials: F
authors.lastname: Bartolo
authors.affiliation: INSA, UPS, INP, LISBP, Université de Toulouse , 135 Avenue de Rangueil, 31077 Toulouse, France.|Département Génie Mathématiques et Modélisation (GMM) , 135 Avenue de Rangueil, 31077 Toulouse, France.
authors.forename: Philippe
authors.initials: P
authors.lastname: Besse
authors.affiliation: INSA, UPS, INP, LISBP, Université de Toulouse , 135 Avenue de Rangueil, 31077 Toulouse, France.|INRA, UMR792 Ingénierie des Systèmes Biologiques et des Procédés (LISBP) ,, 31077 Toulouse, France.|UMR5504, CNRS , 31077 Toulouse, France.|TWB , 3 rue des Satellites, Canal Biotech Building 2, 31400 Toulouse, France.
authors.forename: Jean Marie
authors.initials: JM
authors.lastname: François
authors.affiliation: INSA, UPS, INP, LISBP, Université de Toulouse , 135 Avenue de Rangueil, 31077 Toulouse, France.|INRA, UMR792 Ingénierie des Systèmes Biologiques et des Procédés (LISBP) ,, 31077 Toulouse, France.|UMR5504, CNRS , 31077 Toulouse, France.|TWB , 3 rue des Satellites, Canal Biotech Building 2, 31400 Toulouse, France.
authors.forename: Thomas
authors.initials: T
authors.lastname: Walther
mesh_terms: D000079:Acetaldehyde / Q000031:analogs & derivatives / Q000378:metabolism; D000446:Aldehyde-Lyases / Q000235:genetics / Q000378:metabolism; D004099:Dihydroxyacetone Phosphate / Q000235:genetics / Q000378:metabolism; D004798:Enzymes / Q000235:genetics / Q000378:metabolism; D004926:Escherichia coli / Q000235:genetics / Q000378:metabolism*; D006016:Glycolates / Q000378:metabolism; D060847:Metabolic Engineering / Q000379:methods*; D009154:Mutation; D010428:Pentosephosphates / Q000235:genetics / Q000378:metabolism; D017853:Phosphotransferases (Alcohol Group Acceptor) / Q000235:genetics / Q000378:metabolism; D014994:Xylose / Q000235:genetics / Q000378:metabolism*; D014996:Xylulose / Q000378:metabolism
chemical_list: D004798:Enzymes; D006016:Glycolates; D010428:Pentosephosphates; C031149:glycolic acid; C032498:xylulose-1-phosphate; D004099:Dihydroxyacetone Phosphate; D014996:Xylulose; D014994:Xylose; D017853:Phosphotransferases (Alcohol Group Acceptor); D000446:Aldehyde-Lyases; D000079:Acetaldehyde; C010972:glycolaldehyde
keywords: Escherichia coli; glycolic acid production; synthetic pathway; xylose utilization