Purification and some properties of a novel .ALPHA.-amylase produced by a strain of Thermoactinomyces vulgaris.

An α-amylase [α-1, 4-glucan 4-glucanohydrolase, EC 3.2.1.1.], found in the culture filtrate of a strain of Thermoactinomyces vulgaris, was purified by ammonium sulfate fractionation, and DEAE-cellulose and CM-cellulose chromatographies. The purified enzyme showed a single band on disc gel electrophoresis. The optimum reaction pH and temperature were determined to be around pH 5.0 and 70°C. The isoelectric point was determined to be pH 5.2. The α-amylase was stabilized by Ca2+. The α-amylase was found to hydrolyze pullulan to panose. Therefore, the hydrolytic pattern of this enzyme is different from those of pullulanase and isopullulanase.