TARGETING THE INTRACELLULAR REDOX STATE IN THE DEVELOPMENT OF MORE ROBUST Saccharomyces cerevisiae STRAINS FOR LIGNOCELLULOSIC BIOETHANOL PRODUCTION
Konferensbidrag (offentliggjort, men ej förlagsutgivet), 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.

Författare

Magnus Ask

Chalmers, Kemi- och bioteknik, Industriell Bioteknik

Maurizio Bettiga

Chalmers, Kemi- och bioteknik, Industriell Bioteknik

Valeria Mapelli

Chalmers, Kemi- och bioteknik, Industriell Bioteknik

Varuni Raju Duraiswamy

Chalmers, Kemi- och bioteknik, Industriell Bioteknik

Heidi Höck

Chalmers, Kemi- och bioteknik, Industriell Bioteknik

Lisbeth Olsson

Chalmers, Kemi- och bioteknik, Industriell Bioteknik

ISSY31: 31ST INTERNATIONAL SPECIALISED SYMPOSIUM ON YEAST

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Hållbar utveckling

Ämneskategorier

Industriell bioteknik

Biokemi och molekylärbiologi

Bioenergi

Styrkeområden

Energi

Livsvetenskaper och teknik

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2017-10-08