Some properties of a highly thermostable α-amylase from a Thermoactinomyces sp.

Abstract

Thermostable α-amylase from Thermoactinomyces sp. No. 15, isolated from cow dung, was partially purified and characterized. The enzyme was purified (318-fold) by acetone precipitation, ion-exchange chromatography, and gel filtration techniques. The molecular weight was estimated to be 47 800. Optimum enzyme activity was recorded at pH 7 and at 80 °C. The enzyme was stable at pH 5.0–10.0 and retained 74% activity at 100 °C (30 min). Enzyme activation was observed in the presence of Mn2+, Ag+, and Fe2+, but Hg2+ and Zn2+ were inhibitory. Products of hydrolysis of native starches were mainly glucose and maltose.