Applied Microbiology and Biotechnology

, Volume 90, Issue 3, pp 997–1004

Efficient fermentation of xylose to ethanol at high formic acid concentrations by metabolically engineered Saccharomyces cerevisiae

  • Tomohisa Hasunuma
  • Kyung-mo Sung
  • Tomoya Sanda
  • Kazuya Yoshimura
  • Fumio Matsuda
  • Akihiko Kondo
Applied Genetics and Molecular Biotechnology

DOI: 10.1007/s00253-011-3085-x

Cite this article as:
Hasunuma, T., Sung, K., Sanda, T. et al. Appl Microbiol Biotechnol (2011) 90: 997. doi:10.1007/s00253-011-3085-x

Abstract

Recombinant yeast strains highly tolerant to formic acid during xylose fermentation were constructed. Microarray analysis of xylose-fermenting Saccharomyces cerevisiae strain overexpressing endogenous xylulokinase in addition to xylose reductase and xylitol dehydrogenase from Pichia stipitis revealed that upregulation of formate dehydrogenase genes (FDH1 and FDH2) was one of the most prominent transcriptional events against excess formic acid. The quantification of formic acid in medium indicated that the innate activity of FDH was too weak to detoxify formic acid. To reinforce the capability for formic acid breakdown, the FDH1 gene was additionally overexpressed in the xylose-metabolizing recombinant yeast. This modification allowed the yeast to rapidly decompose excess formic acid. The yield and final ethanol concentration in the presence of 20 mM formic acid is as essentially same as that of control. The fermentation profile also indicated that the production of xylitol and glycerol, major by-products in xylose fermentation, was not affected by the upregulation of FDH activity.

Keywords

Saccharomyces cerevisiaeBioethanolXylose fermentationFormic acidFormate dehydrogenase

Copyright information

© Springer-Verlag 2011

Authors and Affiliations

  • Tomohisa Hasunuma
    • 1
  • Kyung-mo Sung
    • 2
  • Tomoya Sanda
    • 2
  • Kazuya Yoshimura
    • 1
  • Fumio Matsuda
    • 1
  • Akihiko Kondo
    • 2
  1. 1.Organization of Advanced Science and TechnologyKobe UniversityKobeJapan
  2. 2.Department of Chemical Science and Engineering, Graduate School of EngineeringKobe UniversityKobeJapan