Abstract

Bacillus subtilis A10 isolated from orchard soil, Kahramanmaras, Turkey. The enzyme synthesis was observed between pH 7.0-11.0, with an optimum 37°C. The amylase was purified by fractional ammonium sulfate precipitation and sephadex G-100 column. Analysis of the enzyme with sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) revealed a single band which was estimated as 46.9 kDa. The enzyme presented an optimum activity at pH 8.5 and 45°C. Its thermal stability between 20-50°C was about 89.5% for 30 min. The pH stability was observed between pH 7.0 and 10.0 with an average of 84.9% of retaining activity for 15min. The activity of the enzyme was inhibited by SDS and EDTA by 48.4 and 75.9%, respectively. On the other hand, Na₂SO₃ and b-Mercaptoethanol did not effect the enzyme activity. This alkaliphilic amylase is suitable for waste-paper, starch and bioethanol industries.

Key words: Bacillus subtilis, alpha amylase, alkaliphilic, enzyme.