Alternative Feedstocks, Pretreatment/Biochemical

Cost effective enzymatic lignin degradation could play a key role in enabling commercially viable processes for producing fuel ethanol from woody feedstocks, such as corn stover, switchgrass, hybrid poplar, willow, loblolly pine, and eucalyptus. This project focuses on the identification, production, and eventual commercialization of one important class of these enzymes, lignases, which catalyze the degradation of lignin in woody substrates. The biological source of these enzymes is the expressed genomes of termites and their symbionts. Therefore, the approach also involves the identification and commercialization of the cellulases and hemicellulases that typically cooperate with lignases during termite digestion. In Phase I, a subset of R. flavipes termite lignase, hemicellulase, and cellulase enzymes were cloned, produced and partially characterized. In Phase II, (1) additional termite lignases, cellulases, and hemicellulases will be identified, produced, and tested, in order to improve the ability to use these alternative woody feedstocks; and (2) optimized enzyme mixtures will be developed for subsequent commercialization. Commercial Applications and other Benefits as described by the awardee: The technology should contribute to important Presidential directives to produce greater quantities of ethanol biofuel, at greater efficiency, in order to reduce U.S. dependence on foreign oil.