Clostridium thermocellum, cellulase activity

Another thermophilic bacterium, Clostridium thermocellum, possesses a distinct cellulase activity that requires the presence of Ca and a reducing agent, and is more active against crystalline cellulose than amorphous cellulose (12). This particular cellulase exists as a cellulosome, an enormous complex that contains at least 15 different proteins (13), all of which have been cloned and sequenced... 

The synthesis of extracellular cellulase activity by three strains of Clostridium thermocellum growing on cellulose has been shown to be directly related to the degradation of cellulose and to the growth of the bacteria. Cellulase was not detected when the cells grow on cellobiose. The activities of the exo-D-glucanase (pH optimum 5.2, temperature optimum 65 °C) and e do-D-glucanase (pH optimum 5.4, temperature optimum 64 °C) were compared. o-Glucose and cellobiose were released when the crude cellulase acted on cellulose, cellotetraose, and cellotriose in vitro. 

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