Biology Department Seminar

Clostridium thermocellum is a thermophilic, anaerobic, cellulolytic, and ethanogenic bacterium that is capable of directly converting cellulosic materials into ethanol. The C. thermocellum cellulase system exists as a multi-protein complex called the cellulosome. More than 70 enzymatic subunits have been found to be associated with the cellulosome, which include endoglucanases, xylanases, lichenases, and exoglucanases. The core of the cellulosome is a 250-kDa non-catalytic polypeptide, CipA, which binds to cellulose and serves as a scaffold for the catalytic subunits. In addition, the bacterium produces free cellulases that are not associated with the cellulosome. The bacterium is thus capable of producing a large number of glycosyl hydrolases. However, very little is known about the regulation of these enzymes in C. thermocellum. We have supplied the genomic DNA of C. thermocellum to the DOE Joint Genome Institute for determining the genome sequence of this bacterium. The genome sequence is now available. The presentation will review the current knowledge of the C. thermocellum cellulase system and the regulation of its biosynthesis.