Abstract
Ultrasonic waves are irradiated on a enzyme placed in water under a high pressure (0.1〜600MPa), to control the enzyme activity. Using a high pressure vessel shown in Fig.1, the enzyme activity for Trypsin and α-Amylase, is measured in the atmosphere, after two minutes ultrasonic irradiation. The ultrasonic vibrator has a resonant frequency of 1MHz, diameter of 25mm, and electric power of 120W. The PZT ceramic plate is set at the bottom of the vessel, and acoustic streaming is used to maintain the temperature equilibrium in water. Trypsin was activated by ultrasonic irradiation for pressures between 0.1 to 600MPa, as shown in Fig.2, but α-Amylase was not activated as shown in Fig.3. Since it is difficult to generate cavitation in water under high pressure, it is deduced that the enzyme activity is caused by ultrasonic vibration. The water temperature rises to 4℃ after two minutes of ultrasonic irradiation. Ultrasonic waves have a potential to control enzyme activity.
