ENZYMATIC DEGRADATION OF COTTON CELLULOSE BY SEPARATED ENDOCELLULASE AND EXOCELLULASE

In order to prove how endo-and exocellulases (endo 1,4-beta-glucanase and exo 1,4-beta-glucanase) act when they are isolated one from the ot her, the effect of the two separated enzymes on the degree of polymeri zation (DP) and the solubilization of native and acid hydrolyzed cellu loses was studied. The experiments reveal that, in the case of endo-gl ucanase, the high molecular weight cellulose suffers just in the begin ning of the enzymatic action a strong decrease of its DP. Low molecula r weight cellulose degrades until the same number of glucosidic bonds is hydrolyzed as in the high molecular weight cellulose, referring to the same quantities of material. In the experiments with exoglucanase, the DP shows nearly constancy (as it is to expect), but the portion o f solubilized material, although higher than that coming from the hydr olysis with endoglucanase, was very much lower than that occurring by the action of the cellulase multienzyme complex. One can conclude that an isolated endocellulase degrades cellulose also without the presenc e of the synergistic partner, whereas an insolated exoglucanase is not able to attack cotton cellulose in a considerable way. It seems that exoglucanase can only act on cotton cellulose when it works in concert with the endoglucanase.