Robust yeast for feasible lignocellulose based production

Conference poster, 2012

The realisation of a new, oil independent bio-based economy relies on the development of competitive fermentation processes for the production of fuels and chemicals. Next generation cellulosic ethanol has paved the way for a more differentiate portfolio of products. Monomeric sugars are released from polymeric biomass structures such as cellulose and hemicellulose by pretreatment and hydrolysis steps. Harsh conditions result in the formation of a number of compounds, originating from sugars and lignin breakdown and acting as potent inhibitors of the process. Weak organic acids, furaldehydes and phenolic compounds are sources of stress for the fermenting microorganism, as they influence the cellular metabolism in a number of ways, including direct damage on cellular functions or by perturbations of the cellular energy and redox metabolism. Current research carried out by our group focuses on the yeast Saccharomyces cerevisiae and it aims at the identification of the molecular targets of different classes of fermentation inhibitors present in lignocellulose hydrolysate. The final goal is to engineer more robust strains with higher tolerance to lignocellulose hydrolysate and therefore higher productivity. During this presentation the concept of microbial robustness will be discussed and examples of strategies to the design of increased microbial robustness will be given.