The degradation of cotton cellulose by the extracellular cellulase of Myrothecium verrucaria

Abstract

Extracellular extracts of Myrothecium verrucaria have been used to study the mechanism of cellulase action on unmercerized and mercerized cotton cellulose. Relations between loss of weight during hydrolysis and (1) decrease of viscosity-average degree of polymerization and (2) the further loss of weight on heating with alkali have been determined and compared with results similarly obtained by (a) acid degradation of unmercerized cellulose and (b) enzymic degradation of swollen cellulose. These comparisons suggest that the enzyme, being composed of large molecules with restricted mobility in the substrate, removes a number of adjacent glucose residues from each of relatively few sites of attack.