A NEW THERMOSTABLE ENDOGLUCANASE, ACIDOTHERMUS-CELLULOLYTICUS E1 - SYNERGISM WITH TRICHODERMA-REESEI CBH-I AND COMPARISON TO THERMOMONOSPORA-FUSCA E(5)

A new thermostable endoglucanase, Acidothermus cellulolyticus Fl, and another bacterial endoglucanase, E, from Thermomonospora fusca, each e xhibit striking synergism with a fungal cellobiohydrolase (Trichoderma reesei CBH I) in the saccharification of microcrystalline cellulose. In neither case did the ratio of endoglucanase to exoglucanase that de monstrated maximum synergism coincide exactly with the ratio that actu ally released the maximum quantity of soluble sugar for a given total cellulase loading. The difference between the two ratios, after signif icant hydrolysis of the substrate, was considerably larger in the case of A. cellulolyticus E1. For both endoglucanase pairings with CBH I, the offset between the ratio for maximum synergism and the ratio for m aximal soluble sugar production was found to be a function of digestio n time.