Physiological studies of Saccharomyces cerevisiae for increased tolerance against furfural and HMF – two common inhibitors in lignocellulosic hydrolysate

Poster (konferens), 2011

The use of fossil fuels in the transport sector has a significant impact on the environment through the emission of greenhouse gases such as carbon dioxide. Bioethanol is one alternative that has shown potential to at least partly replace fossil fuels. Today’s bioethanol is mainly produced from sugar cane and corn with the yeast Saccharomyces cerevisiae as production organism. Since these raw materials compete with food production, new feedstocks have to be found. A promising alternative is to make use of forest and agricultural residues, so called lignocellulosic materials. Nevertheless, there are many challenges with using lignocellulosic materials for bioethanol production. Since they are recalcitrant to decomposition, harsh conditions have to be used to break down the materials. These conditions tend to produce byproducts that can be inhibitory for the production organism, resulting in lower process productivity. Low productivity is one of the main factors affecting the feasibility of lignocellulosic ethanol production processes. Hydroxymethylfurfural (HMF) and furfural are two compounds that have received a lot of attention during the last years. By studying the effect of these inhibitory compounds on the energy metabolism of S. cerevisiae, the aim of the project is to increase the understanding of the mechanisms by which these inhibitors affect the microorganism. More specifically, the inhibitors effect is studied by quantifying intracellular key compounds such as NADH, NAD+, sugar phosphates and the adenine nucleotide pool. In addition, the biochemical data on intracellular concentrations will be integrated with transcriptomic data. In the future, this knowledge will be used to produce strains that are more tolerant to the process conditions.