[Purification and properties of alpha-amylases in morphological variants of Bacillus subtilis]

Extracellular alpha-amylases were isolated from the culture medium filtrates of Bacillus subtilis R-623 morphological variants R, P and S by means of biospecific chromatography on artificial sorbents and then purified to homogeneity. Some properties of purified alpha-amylases were being studied. The molecular weight of alpha-amylases from Bacillus subtilis variants R, P and S equals 57,000, 58,000 and 56,000, and the isoelectric points are at pH 5.4, 5.6 and 5.1, respectively. pH optimum for alpha-amylase from variants R and P is 4.5, and for that from variant S--5.0. alpha-Amylases from Bacillus subtilis R-623 morphological variants are thermostable enzymes. According to the properties studied, they correspond to Bacillus subtilis alpha-amylases that were isolated and described by other researchers.