Optimal Substrate-Specific Hemicellulase Enzyme Mixtures

With concerns over climate change, national security threats stemming from dependence on foreign oil, and economic dislocation as the global economy adjusts to the end of cheap petroleum, companies and consumers are seeking alternatives to gasoline. Although ethanol produced from renewable cellulosic biomass provides an attractive alternative, the inherent complexity of biomass material has prevented the economical production of ethanol. In particular, the hemicellulose polymers found in all biomass acts as a shield to prevent digestion and processing of cellulose. This project will develop simple enzyme mixtures, derived from the unique marine bacterium Saccharophagus degradans, to remove the protective hemicellulose polymers from biomass, thereby releasing the cellulosic materials for conversion into fermentable sugars and ultimately fuel grade ethanol. S. degradans naturally induces the expression of a vast array of enzymes that degrade all of the polymers. In Phase I, transcriptome analysis will be used identify which enzymes are induced by specific hemicellulose polymers, and a model will be developed to determine how these enzymes interact to degrade these polymers. In Phase II, this information will be used to develop mixtures of expressed enzymes to synergistically remove hemicellulose polymers from pretreated biomass materials. Commercial Applications and other Benefits as described by the awardee:The technology should enable the rapid customization of enzyme mixtures for biomass materials, irrespective of the source, for the production of ethanol. The market that this technology ultimately addresses is predicted to exceed $35 billion in the United States alone by 2021