(257b) Engineering Exogenous Sugar Catabolism in Saccharomyces Cerevisiae for Improved Biofuels Production

Metabolic engineering is a powerful platform for controlling cellular production of biomolecules.  However, the field is still limited by few effective methods to alter the carbon source preference of an organism.  For the case of lignocellulosic biomass conversion, recombinant strains of Saccharomyces cerevisiae are limited in their catabolic rates of pentose sugars.  Specifically, both sugar transport and assimilation steps limit pentose utilization in these strains.  While much progress has been made in altering the pentose assimilation steps, transporter engineering has only recently been shown to be effective.  As an example, we have recently demonstrated how this approach can improve growth rate by 70% by simply altering transporter function.  It is clear that both transporter modifications and catabolic enzyme selection and/or evolution will be necessary for optimizing pentose consumption in S. cerevisiae.  In this talk, we will describe recent progress towards this goal.  Advances in molecular transporter engineering will be discussed alongside downstream pathway optimization strategies.  Synergies between these two approaches will be discussed.  These studies provide insight into the possibility of efficient industrial production of value-added chemicals from lignocellulosic biomass.