Carboxymethyl cellulase (CMCase) assay

Supernatant derived from culture of fungal isolates was also tested for carboxymethyl cellulase activity and used as a source of enzyme. Assay of CMCase activity relied on incubation of enzyme source with Carboxy methyl cellulose (CMC) substrate in Na-acetate buffer (0.05 M, pH 5.3) in a final volume of 3 ml at 50°C for 15 min (Casimir-Schenkel et al., 1996). The reaction was stopped by the addition of 3.0 ml of DNS and the contents were boiled for 15 min in water bath (Miller, 1959). The color developed was read at 540 nm. The amount of reducing sugar liberated was quantified using glucose as standard. One unit of cellulase activity is defined as the amount of enzyme that liberates 1 μmol of glucose equivalents per min under the assay conditions (Mandels et al., 1981).