Applied Microbiology and Biotechnology

, Volume 53, Issue 4, pp 376–382

Xylulose fermentation by mutant and wild-type strains of Zygosaccharomyces and Saccharomyces cerevisiae

  • A. Eliasson
  • E. Boles
  • B. Johansson
  • M. Österberg
  • J. M. Thevelein
  • I. Spencer-Martins
  • H. Juhnke
  • B. Hahn-Hägerdal
ORIGINAL PAPER

DOI: 10.1007/s002530051629

Cite this article as:
Eliasson, A., Boles, E., Johansson, B. et al. Appl Microbiol Biotechnol (2000) 53: 376. doi:10.1007/s002530051629

Abstract

Anaerobic xylulose fermentation was compared in strains of Zygosaccharomyces and Saccharomyces cerevisiae, mutants and wild-type strains to identify host-strain background and genetic modifications beneficial to xylose fermentation. Overexpression of the gene (XKS1) for the pentose phosphate pathway (PPP) enzyme xylulokinase (XK) increased the ethanol yield by almost 85% and resulted in ethanol yields [0.61 C-mmol (C-mmol consumed xylulose)−1] that were close to the theoretical yield [0.67 C-mmol (C-mmol consumed xylulose)−1]. Likewise, deletion of gluconate 6-phosphate dehydrogenase (gnd1Δ) in the PPP and deletion of trehalose 6-phosphate synthase (tps1Δ) together with trehalose 6-phosphate phosphatase (tps2Δ) increased the ethanol yield by 30% and 20%, respectively. Strains deleted in the promoter of the phosphoglucose isomerase gene (PGI1) – resulting in reduced enzyme activities – increased the ethanol yield by 15%. Deletion of ribulose 5-phosphate (rpe1Δ) in the PPP abolished ethanol formation completely. Among non-transformed and parental strains S. cerevisiae ENY. WA-1A exhibited the highest ethanol yield, 0.47 C-mmol (C-mmol consumed xylulose)−1. Other non-transformed strains produced mainly arabinitol or xylitol from xylulose under anaerobic conditions. Contrary to previous reports S. cerevisiae T23D and CBS 8066 were not isogenic with respect to pentose metabolism. Whereas, CBS 8066 has been reported to have a high ethanol yield on xylulose, 0.46 C-mmol (C-mmol consumed xylulose)−1 (Yu et al. 1995), T23D only formed ethanol with a yield of 0.24 C-mmol (C-mmol consumed xylulose)−1. Strains producing arabinitol did not produce xylitol and vice versa. However, overexpression of XKS1 shifted polyol formation from xylitol to arabinitol.

Copyright information

© Springer-Verlag Berlin Heidelberg 2000

Authors and Affiliations

  • A. Eliasson
    • 1
  • E. Boles
    • 2
  • B. Johansson
    • 1
  • M. Österberg
    • 1
  • J. M. Thevelein
    • 3
  • I. Spencer-Martins
    • 4
  • H. Juhnke
    • 5
  • B. Hahn-Hägerdal
    • 1
  1. 1.Department of Applied Microbiology, Lund University, P.O. Box 124, SE-221 00 Lund, Sweden e-mail: Barbel.Hahn-Hagerdal@tmb.lth.se Tel.: +46-46-2228428 Fax: +46-46-2224203SE
  2. 2.Institute of Microbiology, Düsseldorf University, Universitätsstraße 1, D-40225 Düsseldorf, GermanyDE
  3. 3.Laboratorium voor Moleculaire Celbiologie, Katholieke Universiteit Leuven, B-3001 Leuven-Heverlee, BelgiumBE
  4. 4.Biotechnology Unit, Faculty of Science and Technology, New University of Lisbon, P-2825 Monte de Caparica, PortugalPT
  5. 5.Institute of Microbiology, Johann Wolfgang Goethe University, Marie-Curie-Strasse 9, D-60439 Frankfurt/M, GermanyDE