%0 Journal Article
%T Purification and characterization of an alkaline protease from Bacillus licheniformis UV-9 for detergent formulations
%A Muhammad Nadeem
%A Javed Iqbal Qazi
%A Quratulain Syed
%A Muhammad Gulsher
%J Songklanakarin Journal of Science and Technology
%D 2013
%I Songkla University
%X Alkaline protease produced by mutant strain B. licheniformis UV-9 was purified and characterized for its exploitationin detergent formulation. The enzyme was purified to homogeneity by employing ammonium sulphate precipitation andsephadex G-100 gel filtration chromatography with a 36.83 fold increase in specific activity and 11% recovery. The molecularweight of the protease was found to be 36.12 kDa by SDS-PAGE. The Km and Vmax values exhibited by purified proteasewere 5 mg/ml and 61.58¨¬M/ml/min, respectively, using casein as substrate. The enzyme exhibited highest activity at pH 11 andtemperature 60¡ãC. Stability studies showed that the enzyme retained higher than 80% residual activity in the pH and temperature ranges of 8 to 11 and 30 to 50¡ãC, respectively. However, in the presence of 10 mM Ca2+ ions the enzyme tained morethan 90% of its residual activity at pH 11 and temperature 60¡ãC. Phenyl methyl sulphonyl fluoride (PMSF) completelyinhibited the enzyme activity suggesting that it was serine protease. Among metal ions, the Mg2+ and Ca2+ ions enhancedactivity up to 128% and 145%, respectively. The purified enzyme showed extreme stability towards various surfactantssuch as Tween-20, Tween- 45, Tween-65 and Triton X-45. In addition, the enzyme also exhibited more than 100% residualactivity in the presence of oxidizing agents, H2O2 and sodium perborate. These biochemical properties indicate the potentialuse of B. licheniformis UV-9 enzyme in laundry detergents.
%K alkaline protease
%K B. licheniformis
%K purification
%K characterization
%K oxidant stability
%U http://rdo.psu.ac.th/sjstweb/journal/35-2/35-2_187-195.pdf