Effect of ultrasound on the activity of alliinase from fresh garlic

Abstract

Alliinase is a homodimeric glycoprotein found most often in genus Allium plants. In this study, alliinase was purified from fresh garlic by using ammonium sulfate precipitation and gel filtration on a Sephacryl S-200 column. Homogeneity of the purified protein with a molecular weight of 54,000 Da was confirmed by SDS-PAGE. The effect of ultrasound on the alliinase activity was further studied. The optimal parameters for stimulating the alliinase activity were as follows: ultrasonic intensity, 0.5 W/cm(2) and ultrasonic frequency, 40 kHz. Under the optimal conditions, ultrasonic irradiation did not affect the enzyme's optimal temperature and pH, and improved its thermal stability. The low frequency and mild intensity ultrasound could increase the alliinase activity about 47.1%. Under ultrasound, the alliinase activity was inhibited by exogenous pyridoxal 5'-phosphate (PLP) and K(+), and obviously enhanced by Fe(2+). However, PLP and both of the metal ions showed opposite effects in the absence of ultrasound. Ultrasound could retard or slow down the inhibitory effect of l-cysteine on the alliinase activity. These results indicated that the activity of alliinase from fresh garlic might be enhanced by the low frequency and mild intensity ultrasound.

Commercial and Noncommercial Peroxidases Activity under Ultrasound and Microwave Treatment: a Pretreatment to Improve Wastewater Treatment

“…The observed behavior in relation to temperature is partially explained in the study of Wang et al 15 which stated that the sonication of a liquid causes two main effects, cavitation and heating. The shear stress caused by collapsing bubbles may slightly promote a heating that is not measured due to the sensor position, which can result in a local temperature increase, which results in less pronounced effects of temperature on the enzyme activity in the presence of ultrasound.…”

Ultrasound-assisted hydrolysis of sugarcane bagasse using cellulolytic enzymes by direct and indirect sonication

“…Although the experiments were carried out in the same experimental condition, the effective ultrasound power dissipated in the reaction media under indirect sonication is lower than for direct one. Bashari et al (2013) showed that for direct sonication the activity of a dextranase decreased considerably for ultrasound power higher than 40 W. Wang et al (2011) reported that the activity of a cellulase increase until ultrasound power of 15 W under direct sonication, decreasing for higher values. On the other hand, our research group have verified that the activity of some hydrolytic enzymes (cellulase, amylase, inulinase, xylanase) increased under indirect sonication, using an ultrasonic bath with ultrasound power of 136W (Leaes et al, 2013a;Silva et al, 2015;Benazzi et al, 2013).…”

“…Recently, ultrasound process has been used to improve the catalytic activity of enzymes (Szabó and Csiszár, 2013;Wang et al, 2011;Wang et al, 2012;Silva et al, 2013;Nguyen and Le, 2013;Leaes et al, 2013a), increasing the efficiency in the hydrolysis of lignocellulosic materials (Leaes et al, 2013b;Silva et al, 2015;Benazzi et al, 2013), and improving the yield of the biomass pretreatment process (Bharadwaja et al, 2015). The effect of ultrasound could be based on a direct interaction with molecular species as well as on the cavitation phenomenon.…”

Improvement of 2-O-α-D-Glucopyranosyl-L-Ascorbic Acid Biosynthesis Using Ultrasonic Radiation

“…Generally, UR in liquids induced heating and cavitation effects, and improved mass transfer [12]. As a result of this mass transfer, enzyme activity was enhanced due to the movement of reactants to the active site of the enzyme [13]. The hydrolysis rate for 2 h under shaking has been found to increase by 64 % as a result of UR compared to the control samples, which was attributed to less enzyme agglomeration and easier dispersion induced by UR [14].…”