YqhC regulates transcription of the adjacent Escherichia coli genes yqhD and dkgA that are involved in furfural tolerance

Previous results have demonstrated that the silencing of adjacent genes encoding NADPH-dependent furfural oxidoreductases (yqhD dkgA) is responsible for increased furfural tolerance in an E. coli strain EMFR9 [Miller et al., Appl Environ Microbiol 75:4315–4323, 2009]. This gene silencing is now reported to result from the spontaneous insertion of an IS10 into the coding region of yqhC, an upstream gene. YqhC shares homology with transcriptional regulators belonging to the AraC/XylS family and was shown to act as a positive regulator of the adjacent operon encoding YqhD and DkgA. Regulation was demonstrated by constructing a chromosomal deletion of yqhC, a firefly luciferase reporter plasmid for yqhC, and by a direct comparison of furfural resistance and NADPH-dependent furfural reductase activity. Closely related bacteria contain yqhC, yqhD, and dkgA orthologs in the same arrangement as in E. coli LY180. Orthologs of yqhC are also present in more distantly related Gram-negative bacteria. Disruption of yqhC offers a useful approach to increase furfural tolerance in bacteria.

[1]  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.

[2]  A. Martínez,et al.  Conversion of furfural into furfuryl alcohol by saccharomyces cervisiae 354 , 1992 .

[3]  Julio Collado-Vides,et al.  RegulonDB (version 6.0): gene regulation model of Escherichia coli K-12 beyond transcription, active (experimental) annotated promoters and Textpresso navigation , 2007, Nucleic Acids Res..

[4]  D. Yum,et al.  Identification of the yqhE and yafB genes encoding two 2, 5-diketo-D-gluconate reductases in Escherichia coli. , 1999, Applied and environmental microbiology.

[5]  L. Jarboe,et al.  Development of ethanologenic bacteria. , 2007, Advances in biochemical engineering/biotechnology.

[6]  L. Jarboe,et al.  Silencing of NADPH-Dependent Oxidoreductase Genes (yqhD and dkgA) in Furfural-Resistant Ethanologenic Escherichia coli , 2009, Applied and Environmental Microbiology.

[7]  Chankyu Park,et al.  Conversion of Methylglyoxal to Acetol by Escherichia coli Aldo-Keto Reductases , 2005, Journal of bacteriology.

[8]  Bärbel Hahn-Hägerdal,et al.  Fermentation of lignocellulosic hydrolysates. II: inhibitors and mechanisms of inhibition. , 2000 .

[9]  Laura R. Jarboe,et al.  Furfural Inhibits Growth by Limiting Sulfur Assimilation in Ethanologenic Escherichia coli Strain LY180 , 2009, Applied and Environmental Microbiology.

[10]  Akihiko Kondo,et al.  Ethanol fermentation from lignocellulosic hydrolysate by a recombinant xylose- and cellooligosaccharide-assimilating yeast strain , 2006, Applied Microbiology and Biotechnology.

[11]  K. Shanmugam,et al.  Low salt medium for lactate and ethanol production by recombinant Escherichia coli B , 2007, Biotechnology Letters.

[12]  L. Ingram,et al.  Reduction of furfural to furfuryl alcohol by ethanologenic strains of bacteria and its effect on ethanol production from xylose , 2002, Applied biochemistry and biotechnology.

[13]  U. Sauer,et al.  Resistance of Saccharomyces cerevisiae to High Concentrations of Furfural Is Based on NADPH-Dependent Reduction by at Least Two Oxireductases , 2009, Applied and Environmental Microbiology.

[14]  J. M. Sandoval,et al.  Escherichia coli YqhD Exhibits Aldehyde Reductase Activity and Protects from the Harmful Effect of Lipid Peroxidation-derived Aldehydes* , 2008, Journal of Biological Chemistry.

[15]  M. Galbe,et al.  Bio-ethanol--the fuel of tomorrow from the residues of today. , 2006, Trends in biotechnology.

[16]  B. Um,et al.  Effect of sulfuric and phosphoric acid pretreatments on enzymatic hydrolysis of corn stover. , 2003, Applied biochemistry and biotechnology.

[17]  C. Wyman,et al.  Features of promising technologies for pretreatment of lignocellulosic biomass. , 2005, Bioresource technology.

[18]  K. Shanmugam,et al.  Genetic improvement of Escherichia coli for ethanol production: chromosomal integration of Zymomonas mobilis genes encoding pyruvate decarboxylase and alcohol dehydrogenase II , 1991, Applied and environmental microbiology.

[19]  Peter D. Karp,et al.  EcoCyc: A comprehensive view of Escherichia coli biology , 2008, Nucleic Acids Res..

[20]  Gunnar Lidén,et al.  Metabolic effects of furaldehydes and impacts on biotechnological processes , 2009, Applied Microbiology and Biotechnology.

[21]  Ramaraj Boopathy,et al.  Biotransformation of furfural and 5-hydroxymethyl furfural by enteric bacteria , 1993, Journal of Industrial Microbiology.

[22]  A Martinez,et al.  Detoxification of Dilute Acid Hydrolysates of Lignocellulose with Lime , 2001, Biotechnology progress.

[23]  Jae-Gu Pan,et al.  Identification of the yqhE andyafB Genes Encoding Two 2,5-Diketo-d-Gluconate Reductases inEscherichia coli , 1999, Applied and Environmental Microbiology.

[24]  L. Ingram,et al.  Effect of selected aldehydes on the growth and fermentation of ethanologenic Escherichia coli. , 1999, Biotechnology and bioengineering.

[25]  L. Ingram,et al.  Use of UV Absorbance To Monitor Furans in Dilute Acid Hydrolysates of Biomass , 2000, Biotechnology progress.

[26]  D. Belin,et al.  Tight regulation, modulation, and high-level expression by vectors containing the arabinose PBAD promoter , 1995, Journal of bacteriology.