The cellulase activity based on the filter paper unit (FPU) was
measured by incubating 0.3 mL of cellulase supernatant with
0.3 mL of 50 mg Whatman No. 1 filter paper stripped in 0.05 M citrate
buffer (pH 4.8) at 50 C for 1 h. The activity of the hydrolyti cenzyme was based on the determination of the reducing sugars liberated
from the substrate using the DNS test.