10.22376/ijpbs.2019.10.1.p1-12 Volume 2 Issue 3 2011 (July - September) The extracellular protease produced by lessThan i greaterThan Bacillus subtilis lessThan /i greaterThan DKMNR was purified using ammonium sulphate precipitation and Sephadex G-100 column chromatography. SDS-PAGE analysis revealed that this protease is monomeric in nature and has molecular weight of 43 kDa. The protease belongs to serine-type with more specificity for casein compared to BSA, egg albumin and gelatin. The enzyme activity was positively influenced by the presence of Ca lessThan sup greaterThan 2+ lessThan /sup greaterThan , Mg lessThan sup greaterThan 2+ lessThan /sup greaterThan and Mn lessThan sup greaterThan 2+ lessThan /sup greaterThan ions and negatively affected by Fe lessThan sup greaterThan 2+ lessThan /sup greaterThan and Ba lessThan sup greaterThan +2 lessThan /sup greaterThan ions. The produced enzyme has showed highest activity at 70 lessThan sup greaterThan o lessThan /sup greaterThan C and also possesses good thermostablity at above 70 lessThan sup greaterThan o lessThan /sup greaterThan C. The kinetic data revealed that the obtained enzyme has K lessThan sub greaterThan m lessThan /sub greaterThan of 0.7614 mg mL lessThan sup greaterThan -1 lessThan /sup greaterThan and V lessThan sub greaterThan max lessThan /sub greaterThan of 2582 U min lessThan sup greaterThan -1 lessThan /sup greaterThan .The lower activation energy of 41.082 kJ/mol/k shows that the enzyme is more stable at higher temperature and also highly reactive. Devarapalli Kezia, G. Chandrakala, Velaga Prasanthi, S.V. Naidu And M.Narasimha Rao Protease production, Bacillus subtilis, purification, activation energy, thermostability of enzyme and enzyme kinetics. 73-85