Biotechnology of yeast biofuel production

Carbohydrates make up most of the organic matter on earth and serve as major biological fuels. This has resulted in increasing interest in developing technology aimed at utilizing carbohydrates to produce biofuels. Lignocellulosic bioethanol production is particularly attractive in this regard since it offers an alternative source of carbohydrate to that already used as food sources. The main carbohydrate components of lignocellulose are glucose and xylose. Glucose serves as a primary biofuel for most organisms and can repress the synthesis of other carbon metabolizing enzymes through the effects of carbon catabolite repression. The objective of this proposal is to investigate the steps that limit the capacity of Saccharomyces cerevisiae to ferment xylose to ethanol and thus to identify how this process can be significantly improved, such that the utilisation of lignocellulose biomass by this organism can become a viable route to production of bioethanol. A major focus will be on the post-transcriptional control of mRNAs expressing key components of xylose metabolism. Our preliminary experiments indicate that the pathways of xylose breakdown are regulated by both transcriptional and translational mechanisms, and it is only by considering all of gene expression that we can truly understand the production of bioethanol from lignocellulose.