TARGETING THE INTRACELLULAR REDOX STATE IN THE DEVELOPMENT OF MORE ROBUST Saccharomyces cerevisiae STRAINS FOR LIGNOCELLULOSIC BIOETHANOL PRODUCTION
Conference contribution, 2014

Bioethanol produced from lignocellulosic raw materials is a promising alternative to fossil fuels and to decrease greenhouse gas emissions, but several challenges still exist. When lignocellulosic biomass is pretreated, a number of undesired degradation products are generated, among which the furaldehydes furfural and hydroxymethylfurfural (HMF) have shown to impede growth and limit ethanol productivity of the yeast Saccharomyces cerevisiae. In the present study, a recombinant, xylose-utilizing S. cerevisiae strain was challenged with sub-lethal concentrations of furfural and HMF in anaerobic batch cultivations. By pulsing furaldehydes in either the glucose or the xylose consumption phase, perturbations in the intracellular NAD(P)H/NAD(P)+ ratios could be demonstrated. A genome-wide study of transcription found that genes related to NADPH-requiring processes, such as nitrogen and sulphur assimilation, were significantly induced. Moreover, the protective metabolite and antioxidant glutathione was identified as the highest scoring reporter metabolite in the transcriptome analysis. S. cerevisiae strains overproducing glutathione were constructed and the resulting strains were evaluated in simultaneous saccharification and fermentation (SSF) of pretreated spruce. The results from the present study provide valuable insights of how S. cerevisiae responds to stress imposed by HMF and furfural and how such information could be used to engineer more robust yeast strains.

Author

Magnus Ask

Chalmers, Chemical and Biological Engineering, Industrial biotechnology

Maurizio Bettiga

Chalmers, Chemical and Biological Engineering, Industrial biotechnology

Valeria Mapelli

Chalmers, Chemical and Biological Engineering, Industrial biotechnology

Varuni Raju Duraiswamy

Chalmers, Chemical and Biological Engineering, Industrial biotechnology

Heidi Höck

Chalmers, Chemical and Biological Engineering, Industrial biotechnology

Lisbeth Olsson

Chalmers, Chemical and Biological Engineering, Industrial biotechnology

ISSY31: 31ST INTERNATIONAL SPECIALISED SYMPOSIUM ON YEAST

Driving Forces

Sustainable development

Subject Categories

Industrial Biotechnology

Biochemistry and Molecular Biology

Bioenergy

Areas of Advance

Energy

Life Science Engineering (2010-2018)

More information

Created

10/8/2017