Engineering of a Synthetic Metabolic Pathway for the Assimilation of (d)-Xylose into Value-Added Chemicals

• DOI: 10.1021/acssynbio.5b00103
• Publication Date: 2015-07-17T15:10:30Z
• Authors: Yvan Cam; Ceren Alkim; Debora Trichez; Vincent Trebosc; Amélie Vax; François Bartolo; Philippe Besse; Jean Marie François; Thomas Walther
• Keywords: Glycolaldehyde; Metabolic Engineering; Glycolic acid; Xylose metabolism; Metabolic pathway; Dihydroxyacetone phosphate; Dihydroxyacetone

A synthetic pathway for (d)-xylose assimilation was stoichiometrically evaluated and implemented in Escherichia coli strains. The proceeds via isomerization of to (d)-xylulose, phosphorylation (d)-xylulose obtain (d)-xylulose-1-phosphate (X1P), aldolytic cleavage the latter yield glycolaldehyde DHAP. Stoichiometric analyses showed that this provides access ethylene glycol with a theoretical molar 1. Alternatively, both DHAP can be converted glycolic acid is 20% higher than exclusive production glyoxylate shunt. Simultaneous expression xylulose-1 kinase X1P aldolase activities, provided by human ketohexokinase-C aldolase-B, respectively, restored growth (d)-xylulose-5-kinase mutant on xylose. This strain produced as major metabolic endproduct. Metabolic engineering strains assimilated entire C2 fraction into central metabolism or 4.3 g/L at 0.9 shake flasks.