Effects of ultrasound on cellulolytic activity of cellulase complex

This study focused on the effects of ultrasound on the catalytic activity of cellulase preparation. Diluted Celluclast 1.5L in citrate buffer was treated by ultrasound with different variables. The catalytic activity of the treated and untreated enzymes was determined against soluble and insoluble substrates. Changes in ultrasonic intensity and sonication time significantly affected the enzyme activity. The cellulolytic activity increased when the ultrasonic intensity augmented from 0 to 6 W/mL and the treatment time prolonged from 0 to 80 sec. It was due to some slight changes in spatial structure of enzyme molecules, which supported the formation of enzymesubstrate complex and improved the adsorption of cellulase on insoluble cellulose. When the cellulase solution with the soluble protein concentration of 1.68 mg/mL was sonicated for 80 sec with the ultrasonic intensity of 6 W/mL, its catalytic activity was enhanced 18.7% against carboxymethylcellulose (CMC) and 39.4% against Whatman No. 1 filter paper. For higher ultrasonic intensity and longer treatment time, the cellulolytic activity reduced sharply.