Biology Department Seminar

We have been studying the high G-C gram variable soil bacterium, Thermobifida fusca, a moderate thermophile, for more than 20 years, as it is a major microorganism degrading plant cell walls in heated plant wastes such as compost piles. Its genome sequence has just been finished by the Joint Genome Institute of the DOE (http://genome.jgi-psf.org/draft_microbes/thefu/thefu.home.html). We have cloned, expressed and characterized the activity of the expressed proteins of six cellulase genes, two xylanase genes, a xyloglucanase gene, a b-1,3 glucanase gene, a b-glucosidase gene, and a regulatory gene, CelR. Three-dimensional structures have been determined for the catalytic domains of three of the cellulases and the xyloglucanase, while structures for a cellulase and the b-1,3 glucanase are being determined. Extensive site directed mutagenesis studies have been carried out on one of the cellulases and such studies have started on two others. We are developing tools to construct gene knockouts in T. fusca. The work in my laboratory was summarized in a recent article (Wilson, D.B. Studies of Thermobifida fusca plant cell wall degrading enzymes. Chem. Rec. 4, 72-82, 2004).