Selective reduction of xylose to xylitol from a mixture of hemicellulosic sugars.

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.

[1]  José Manuel Domínguez,et al.  Biotechnological production of xylitol. Part 1: Interest of xylitol and fundamentals of its biosynthesis , 1998 .

[2]  E. Lin,et al.  A mutant crp allele that differentially activates the operons of the fuc regulon in Escherichia coli , 1988, Journal of bacteriology.

[3]  Jung-Woo Kim,et al.  Directed Evolution of Thermus Maltogenic Amylase toward Enhanced Thermal Resistance , 2003, Applied and Environmental Microbiology.

[4]  D. Ladant,et al.  Relief of catabolite repression in a cAMP-independent catabolite gene activator mutant of Escherichia coli. , 2004, Research in microbiology.

[5]  D. Oh,et al.  Increased xylitol production rate during long-term cell recycle fermentation of Candida tropicalis , 2004, Biotechnology Letters.

[6]  Huimin Zhao,et al.  Heterologous Expression, Purification, and Characterization of a Highly Active Xylose Reductase from Neurospora crassa , 2005, Applied and Environmental Microbiology.

[7]  S. Totey,et al.  Influences of yeast extract on specific cellular yield of Ovine growth hormone during fed-batch fermentation of E. coli , 2000 .

[8]  B. Dien,et al.  Use of catabolite repression mutants for fermentation of sugar mixtures to ethanol , 2001, Applied Microbiology and Biotechnology.

[9]  Francisco Bolívar,et al.  Replacement of the glucose phosphotransferase transport system by galactose permease reduces acetate accumulation and improves process performance of Escherichia coli for recombinant protein production without impairment of growth rate. , 2006, Metabolic engineering.

[10]  L. Ingram,et al.  Improved strains of recombinant Escherichia coli for ethanol production from sugar mixtures , 1995, Applied Microbiology and Biotechnology.

[11]  B. Saha,et al.  Hemicellulose bioconversion , 2003, Journal of Industrial Microbiology and Biotechnology.

[12]  M. Eiteman,et al.  Overcoming acetate in Escherichia coli recombinant protein fermentations. , 2006, Trends in biotechnology.

[13]  S. Coldwell,et al.  How xylitol-containing products affect cariogenic bacteria. , 2002, Journal of the American Dental Association.

[14]  J. C. Santos,et al.  Use of a fluidized bed reactor operated in semi-continuous mode for xylose-to-xylitol conversion by Candida guilliermondii immobilized on porous glass , 2003 .

[15]  P. Cirino,et al.  Role of xylose transporters in xylitol production from engineered Escherichia coli. , 2008, Journal of biotechnology.

[16]  P. Cirino,et al.  Heterologous expression of D-xylulokinase from Pichia stipitis enables high levels of xylitol production by engineered Escherichia coli growing on xylose. , 2009, Metabolic engineering.

[17]  M. P. Bryant,et al.  Growth of Eubacterium limosum with Carbon Monoxide as the Energy Source , 1982, Applied and environmental microbiology.

[18]  Jeffrey H. Miller.  A Short Course in Bacterial Genetics: A Laboratory Manual and Handbook for Escherichia coli and Rela , 1992 .

[19]  J. Fitch,et al.  Real-time characterization of virulence factor expression in Yersinia pestis using a GFP reporter system. , 2004, Biochemical and biophysical research communications.

[20]  Paul Christakopoulos,et al.  Comparative metabolic network analysis of two xylose fermenting recombinant Saccharomyces cerevisiae strains. , 2005, Metabolic engineering.

[21]  Jay D. Keasling,et al.  Directed Evolution of AraC for Improved Compatibility of Arabinose- and Lactose-Inducible Promoters , 2007, Applied and Environmental Microbiology.

[22]  Huimin Zhao,et al.  Evolution in Reverse: Engineering a D‐Xylose‐Specific Xylose Reductase , 2008, Chembiochem : a European journal of chemical biology.

[23]  T. Jeffries,et al.  Effects of Gene Orientation and Use of Multiple Promoters on the Expression of XYL1 and XYL2 in Saccharomyces cerevisiae , 2008, Applied biochemistry and biotechnology.

[24]  Jin-Ho Seo,et al.  Production of xylitol by recombinant Saccharomyces cerevisiae containing xylose reductase gene in repeated fed-batch and cell-recycle fermentations , 2004 .

[25]  B. Görke,et al.  Carbon catabolite repression in bacteria: many ways to make the most out of nutrients , 2008, Nature Reviews Microbiology.

[26]  B. Wanner,et al.  One-step inactivation of chromosomal genes in Escherichia coli K-12 using PCR products. , 2000, Proceedings of the National Academy of Sciences of the United States of America.

[27]  Huimin Zhao,et al.  Directed Evolution of a Thermostable Phosphite Dehydrogenase for NAD(P)H Regeneration , 2005, Applied and Environmental Microbiology.

[28]  W M Edgar,et al.  Sugar substitutes, chewing gum and dental caries--a review , 1998, British Dental Journal.

[29]  W. Boos,et al.  Glycerol‐3‐phosphate‐mediated repression of malT in Escherichia coli does not require metabolism, depends on enzyme IIAGlc and is mediated by cAMP levels , 1999, Molecular microbiology.

[30]  A. Danchin,et al.  The catalytic domain of Escherichia coli K-12 adenylate cyclase as revealed by deletion analysis of the cya gene , 1994, Molecular and General Genetics MGG.

[31]  L. Ingram,et al.  Engineering Escherichia coli for xylitol production from glucose‐xylose mixtures , 2006, Biotechnology and bioengineering.