Purification and characterization of alkaline protease from a mutant of bacillus polymyxa

Alkaline protease from a mutant of Bacillus polymyxa was purified to 99 fold with 10 per cent recovery using (NH4)2SO4 fractionation, DEAE-cellulose chromatography and gel filtration through Sephadex G-100. The molecular weight of the enzyme as determined by SDS-PAGE was found to be 31 kD. The enzyme acted optimally at pH 9.25 and 70°C. It was thermostable and retained full activity after 1 h incubation at 50° C. It was inhibited by Cu2+, Hg2+, EDTA and PMSF. The enzyme retained more than 50 per cent activity after 30 min incubation at 35° C in the presence of detergents, such as Avis and Vim ultra, indicating its suitability for application in detergent industry