Isolation, purification and characterization of carboxymethyl cellulase (CMCase) from endophytic Fusarium oxysporum producing podophyllotoxin

Abstract

Endophytic fungus Fusarium oxysporum is a rich source of cellulases. In the present study, the highest activity was reported at 28˚C, pH 5.6 with 2% Carboxymethyl cellulose (CMC) as carbon source. CMC was purified using Sephadex G and DEAE cellulose chromatography to 15.9 folds and the molecular weight was determined to be 84 kDa by SDS-PAGE analysis and was subsequently characterized. The purified enzyme was stable over the pH range from 4.0 to 8.0 and at temperatures below 50˚C. The enzyme was highly active on CMC and reduced or no activity on Avicel, cellobiose and it was suggested to be CMCase/endoglucanase. The activity of endoglucanase was enhanced in the presence of MgCl2, CoCl2, FeCl3, CaCl2, FeCl2 and intensive to HgCl2. The purified enzyme showed its optimum activity at pH 5.0 - 6.0 and was quite stable at 50˚C for 30 min and retained 45% of original activity.