[Relationship between the kinetics of hydrolysis of soluble and native celluloses under the action of cellulase multi-enzyme complexes]

Abstract

The kinetics of cellulase multi-enzyme complex under steady- and non-steady-state conditions have been studied. To verify the kinetic regularities obtained the action of eight different cellulases from Trichoderma, Geotrichum and Aspergillus has been studied with respect to ball milled cotton linters. On the other hand, the activities of the individual components of cellulase complexes, i.e. endoglucanase, exoglucosidase and cellobiase have been determined with respect to soluble cellulose derivatives. Theoretical and experimental evidence for the existence of a linear correlation between the rate of hydrolysis of native cellulose under certain experimental conditons, on the one hand, and that of its soluble polymeric compounds (particularly, carboxymethyl cellulose) on the other, have been obtained. The kinetics of the cellulase multi-enzyme system suggest that this correlation is a substantiation of the fact that endoglucanse is a cellulolytic component which is the first to attack native cellulose. The data obtained contradict the hypothesis being discussed in literature for the last 30 years about the presence in cellulase complexes of some "pre-hydrolytic C1-enzyme", which presumably attacks native cellulose. Evidently, a hypothetical "C1-enzyme" is the endoglucanase of random action.