Optimization of Protease Activity of Thermophilic Bacillus subtilis WIFD5 Isolated from Milk Powder
Sakshi Sharma and K. Aruna*Department of Microbiology, Wilson College, Mumbai - 400 007, (India).
Abstract: Potential thermophilic extracellular protease producer Bacillus subtilis WIFD5 was isolated from a milk powder sample. Various parameters were studied for optimum protease enzyme activity. A temperature of 550C and pH 9 gave maximum enzyme activity while 5mM PMSF inhibited the enzyme activity thereby classifying it to be thermophilic serine alkaline protease. Enzyme displayed good activity at 0.5% H2O2 indicating it to be bleach stable. Among different solvents and surfactants tested, 20% v/v toluene and 0.5% Tween-20 exhibited the maximum enzyme activity respectively demonstrating detergent stability of the enzyme. Ca2+ and Mg2+ ions enhanced the enzyme activity suggesting a cofactor requirement for the enzyme.Purification of the enzyme was done using ammonium sulphate precipitation method. Application of protease to remove blood stains from cotton fabrics indicated its potential use in detergent formulations.
Keywords: Protease; PMSF; Detergent; Thermophile Back to TOC