THE ALKALINE AMYLASE OF THE ALKALOPHILIC BACILLUS SP IMD-370

A novel extracellular amylase of alkalophilic Bacillus sp. IMD 370 was purified to homogeneity and displayed maxima for activity at pH 10.0 and 40 degrees C. It had an isoelectric point of 4.9 and a relative mo lecular mass of 159,000 as estimated by sodium dodecyl sulfate-polyacr ylamide gel electrophoresis, and was inhibited (47%) by ethylenediamin etetraacetic acid (1 mM). The alpha-amylase of Bacillus sp. IMD 370 wa s quite distinct by virtue of its mechanism of action and its inabilit y to fit into the conventional classification scheme of amylolytic enz ymes. It had a mode of action intermediate between an endo-acting enzy me, alpha-amylase, and a typical exo-acting enzyme, amyloglucosidase. The sugars produced on hydrolysis of starch had the alpha-configuratio n, but no oligosaccharide higher than maltotetraose was obtained at an y stage during starch hydrolysis.