Characterization of an acidophilic and thermostable α‐amylase from Alicyclobacillus sendaiensis NUST

Abstract

AbstractThis paper describes the characterization of an acidophilic and thermostable α‐amylase from Alicyclobacillus sendaiensis NUST. The MW of this enzyme was estimated to be 56 kDa by SDS–PAGE. The enzyme was stable over a range of pH from 2.5 to 5.5 with an optimum around 3.5. Maximum activity of the α‐amylase was observed at pH 3.5 and 85°C in the presence of soluble starch as substrate. The enzyme activity was decreased by Mg2+, Cu2+, Zn2+, Al3+, K+, Li+, Ag+, urea, EDTA, trichloroacetic acid and Tween 60 and inhibited by Hg2+, Ce2+ and SDS, whereas the activity was increased by Mn2+, DTT, and β‐mercaptoethanol. Ca2+and Fe2+ did not affect the enzyme activity.