Effect of Ultrasound Radiation on the Activity of Cyclodextrin Glucanotransferase

In this study, the effects of ultrasound radiation pretreatment on activity and conformation of cyclodextrin glucanotransferase (CGTase) from Bacillus sp. SK13.002 were investigated. Conformational change on the enzyme structure was studied by fluorescence spectroscopy. Findings showed that the optimum ultrasound radiation pretreatment condition was 25 KHz, 30 W for 20 min in which the activity of CGTase was significantly increased by 22% compared to the conventional (without ultrasound pretreatment) thermal treatment at 65C. At optimum ultrasound radiation pretreatment, fluorescence spectra showed that the intensity of ultrasound pretreated CGTase was increased by 88% compared to the control, indicated that more buried Trp residues came to surface. This conformational change was reflected in enhancing the CGTase activity.