Development of an engineered cellulosome-based cellulase/hemicellulase system for efficient, cost-effective hydrolysis of cellulose from agricultural and woody feedstocks

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A fairy tale from the Grimm brothers (Rumpelstilskin) talks about turning straws into gold. In this proposal,new technologies will be developed in areas of nano- and bio-technologies to turn agricultural (corn stovers,wheat straws) and woody (wood chips and sawdust) feedstocks to green gold (biofuels in the form of ethanol).The green gold technology is significantly different from the traditional black gold (petroleum) technology intwo aspects. 1. The process of extracting crude oil from the ground and using gasoline as the transport fuelrelease significant amounts of greenhouse gases (GHG). These GHGs have been linked to global warmingwhich can have significant impacts to mankind in the near future. The use of ethanol as the transport fuel canminimize GHG emission. 2. In contrast to crude oil which can one day be depleted, bioethanol can begenerated from renewable sources. Currently, three technologies are involved in bioethanol production. Theseinclude sugar ethanol from sugarcane in Brazil, grain ethanol from corn and wheat in North America andcellulosic ethanol from corn stovers and wheat straws from many countries. Since Canada is not ideal forsugarcane cultivation and the grain ethanol approach has caused a major concern with the perception of foodfor fuel, cellulosic ethanol is the best choice for Canada. However, the enzymes (cellulases and hemicellulases)required to break down cellulose to glucose are relatively complex and costly. New technologies to improve theactivities of these enzymes and to lower the production cost would be needed. In this proposal, a tiny proteinplatform will be engineered to capture different enzymes to form a nano-enzyme complex which can workcooperatively to break down cellulose. These enzymes will be assembled on the platform in a predeterminedorder. Degradation intermediates will diffuse from one enzyme to the other in close proximity. Highly efficientenzymes are selected to incorporate into the platform. All these components will be recombinantly producedusing a microbial factory (Bacillus subtilis, a non-pathogenic bacterium) developed in my laboratory. Thesetechnologies, if successfully developed, will allow cellulosic ethanol production to be truly cost-effective.