The effect of low-frequency ultrasound on the activity and efficiency of a commercial cellulase enzyme

A commercial acidic cellulase enzyme complex was chosen in order to gain detailed information about the effect of low-frequency ultrasound (horn at 40 kHz) on the enzyme activity. The performance of the enzyme under sonication was also evaluated in a cellulose-cellulase model reaction. The filter paper activity of the enzyme and the yield of the enzyme catalysed hydrolysis were determined as a function of the parameters of the sonicated environment (treatment time, amplitude, with and without a reflector) and compared with the data measured in a non-sonicated bath. Depending on the parameters of the sonication, the enzyme is susceptible to ultrasound and its activity can significantly decrease. Despite the serious reduction of the enzyme activity, the outcome of the enzyme catalysed hydrolysis was always positive, implying that the advantageous effects of sonication impressed on the heterogeneous enzyme reaction always overcome the undesirable enzyme modifying effect of ultrasound.