title: Selective reduction of xylose to xylitol from a mixture of hemicellulosic sugars.
abstract: The biocatalytic reduction of D-xylose to xylitol requires separation of the substrate from L-arabinose, another major component of hemicellulosic hydrolysate. This step is necessitated by the innate promiscuity of xylose reductases, which can efficiently reduce L-arabinose to L-arabinitol, an unwanted byproduct. Unfortunately,due to the epimeric nature of D-xylose and L-arabinose, separation can be difficult, leading to high production costs. To overcome this issue, we engineered an E. coli strain to efficiently produce xylitol from D-xylose with minimal production of L-arabinitol byproduct. By combining this strain with a previously engineered xylose reductase mutant, we were able to eliminate L-arabinitol formation and produce xylitol to near 100% purity from an equiweight mixture of D-xylose, L-arabinose, and D-glucose.
authors.affiliation: Department of Chemical and Biomolecular Engineering, Institute for Genomic Biology, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA.
authors.forename: Nikhil U
authors.initials: NU
authors.lastname: Nair
authors.forename: Huimin
authors.initials: H
authors.lastname: Zhao
mesh_terms: D000449:Aldehyde Reductase / Q000502:physiology*; D001089:Arabinose / Q000378:metabolism*; D004926:Escherichia coli / Q000502:physiology*; D024861:Genetic Enhancement / Q000379:methods*; D011134:Polysaccharides / Q000378:metabolism*; D011994:Recombinant Proteins / Q000378:metabolism; D014993:Xylitol / Q000378:metabolism*; D014994:Xylose / Q000378:metabolism*
chemical_list: D011134:Polysaccharides; D011994:Recombinant Proteins; C007916:hemicellulose; D014994:Xylose; D001089:Arabinose; D000449:Aldehyde Reductase; D014993:Xylitol