Studies on Crude Thermostable Amylase Produced by Bacillus Spp. Isolated from Starch Waste

Thermostable amylase secreting bacterium was isolated through a high temperature screening procedure. The choice isolate, identified as Bacillus spp. , appeared to be a facultative thermophile. Production of crude enzyme by the isolate was better when the medium was supplemented with organic nitrogen sources than the inorganic ones. The enzyme has an optimum activity at pH of 9.0, temperature of 65 0C and retains 82% of its activity at 70oC. The crude enzyme�s activity was stimulated by 2mM Ca2+, Mg2+, Zn2+ and Cu2+ but inhibited by EDTA, Acrylamide, dodecyl-sulfate, Fe2+ and Mn2+. It also showed resistance to both oxidizing and denaturating agents.