Discovery and Optimization of Cellobiohydrolase

70920S02-II There is a need for more cost effective enzyme systems for the conversion of lignocellulosic biomass to fermentable sugars for the production of ethanol. Cellobiohydrolase could be an effective enzyme for the efficient breakdown of lignocellulose, but little effort has been expended on improving the technical efficacy of this class of cellulases, either by harnessing natural biodiversity or by using directed evolution technologies. In this project, highly active naturally-occurring cellobiohydrolases will be identified and characterized in order to identify the best candidate for hydrolysing lignocellulose. In Phase I, high-throughput methods were developed for the screening of large numbers of variants of a single cellobiohydrolases, in order to find mutants with improved technical efficacy on lignocellulose. In Phase II, a discovery program will be implemented to identify the most active cellobiohydrolases in biomass samples collected widely from the natural world. Following biochemical characterization, directed evolution will be used to further improve the activity of the leading candidate on lignocellulosic feedstocks relevant to the production of renewable fuels. Commercial Applications and Other Benefits as described by awardee: A novel cellobiohydrolase, highly active on the lignocellulose feedstocks commonly used for the production of renewable fuels, should significantly improve the efficiency and economics of enzymatic lignocellulose conversion.