Abstract

The α-amylase was purified from Aspergillus sp. JP-1 and some enzyme characteristics were studied. The enzyme waw approzimately purified 80-fold and an overall yield was 16.5% from the culture medium by ammonium sulfate fractionation, Sephadex G-150 gel permeation chromatography, and DEAE-Sephadex A-50 ion exchange column chromatography in order. The molecular weight of the purified α-amylase has been estimated to be 56 KDa on SDS-polyacrulamide gel electrophoresis and Sephadex G-150 chromatography. The purigied enzyme functions optimally at pH5.5 and 40℃, respectively. The Km value for soluble starch was 2.5 mg/ml. The enzymatic activity increased in the presence of Ca^2+, Co^2+, EDTA, Mg^2+, Mn^2+ and Zn^2+ and was inhibited by adding Cu^2+, Fe^2+, and Ni^2+.

• Keywords: Aspergillus; α-amylase; purification