The Cellulosome of Clostridium thermocellum

The accelerated interest in microbial cellulases stems from their potential industrial application. This area is an excellent example in which basic and applied science are closely interlinked: the better understood the mechanism of cellulase action; the better can be the applicative value as a biotechnological process. This chapter presents a new concept concerning the mode of cellulose degradation. In this mode, the model organism, the cellulosome is anchored to the cell surface in polycellulosomal centers, which also mediate the adherence of the bacterium to the insoluble substrate. Moreover, the cellulosome concept can be considered to encompass the general organization of various complementary cellulases and related components into defined complexes, which may form larger polycellulosoma structures. Finally, the cellulosome concept may bear particular relevance to other microbial systems wherein other structurally complex insoluble polymers (for example, starch, chitin, and various insoluble proteinaceous matrices) are degraded enzymatically.