Purification of Bacillus circulans F-2 Amylase and Its General Properties

Abstract

An extracellular amylase produced by Bacillus circulans F-2 was purified to show a single band on SDS polyacrylamide gel electrophoresis. The purified enzyme has a molecular weight of 93,000, an optimum pH of 6.0~6.5 and an optimum temperature of 60°C. On isoelectric focusing, the enzyme exhibited 2 bands with isoelectric points of 4.88 and 4.93. When acting on amylaceous polysaccharides, the enzyme removed maltohexaose from their non-reducing ends but the produced maltohexaose was then split into maltotetraose and maltose. Although it digested corn starch granules at approximately the same rate as porcine pancreatic and Streptococcus bovis amylases, it digested potato starch granules far faster than those amylases.