Effects of ultrasonication variables on the activity and properties of alpha amylase preparation

Abstract

Recently, ultrasound was demonstrated to increase enzyme activity in food industry. In most studies, an enzyme-substrate mixture was ultrasonicated. Very little is reported on the ultrasonication of enzyme preparation; the effects of ultrasonication variables on the enzyme activity and properties remained unclear. In this study, an α-amylase preparation was ultrasonicated under different conditions. At the ultrasonic frequency, power, temperature, and time of 20 kHz, 25 W/mL, 30°C, and 75 s, respectively, the secondary structure of the α-amylase was changed and that improved the catalytic activity by 47% over the control. The optimal temperature and pH of the α-amylase preparation did not change under the ultrasonic treatment. In addition, ultrasonic treatment increased kinetic parameters of the α-amylase including maximal velocity V , Michaelis constant K , turnover number K , and catalytic specificity constant K /K . Nevertheless, the ultrasonicated α-amylase had lower thermal inactivation rate constant and half-life value than the nonultrasonicated enzyme. Ultrasonic treatment can be considered as a novel solution for improvement in enzyme activity. © 2018 American Institute of Chemical Engineers Biotechnol. Prog., 34:702-710, 2018.

Ultrasound-Assisted Intensification of β-Glucosidase Enzyme Activity in Free and Immobilized Forms

“…When the power was increased beyond 25 W/mL, a reduction in activity was observed attributed to the possible generation of enough radicals, which affected the enzyme conformation adversely. 61 The comparison of the current results with literature results established the importance of the current work as the optimum power dissipation was specific to enzymes.…”

Recent advances in ultrasound application in fermented and non‐fermented dairy products: antibacterial and bioactive properties

“…On the other hand, cavitation leads to the production of the free radicals which react with the amino acid residues of enzyme structures that have a key role in the stability, the catalytic activity of enzymes, and substrate binding and as a result, the activity of enzymes will be changed. On the other side, short exposure to ultrasound can increase enzyme activity (Chaisuwan et al ., 2020b) and its potential to improve the activity of many enzymes such as dextranase, α‐amylase, lipase, and β‐d‐glucosidase has been reported (Nadar & Rathod, 2017; Tran et al ., 2018; Sun et al ., 2019). Ultrasound can change the conformation of enzymes, being the conformational changes a critical role in catalysis process.…”

Ultrasound-Assisted Intensification of Activity of Free and Immobilized Enzymes: A Review

“…According to the results, there was an increase in conversion as power increased from 70 to 100 W. After 100 W power, the conversion decreased and was attributed to denaturation/deactivation of the enzyme due to altering of the enzyme structure at high power ultrasonic treatment. In another study, Tran et al 26 investigated the effect of different ultrasonic parameters on αamylase activity in an ultrasonic horn operated with 20 kHz frequency. The author analyzed the effect of power over the range of 10−35 W/mL on the alpha enzyme activity.…”

“…At the optimum reaction temperature of 55 °C, a reduction of 13.2% in enzyme activity was observed after 1 h of processing clearly indicating that optimization of conditions and application to specific enzymes is important. Tran et al 26 pretreated the α-amylase enzyme with ultrasound in an ultrasonic horn reactor to analyze the changes in enzyme activity before and after ultrasonication. The enzyme solution was irradiated at ultrasound conditions of 25 W/mL, treatment time of 75 s, and 30 °C.…”