Serratia속의 신균주가 생산하는 단백질분해효소

Studies on proteolytic enzyme from A New Strain in Serratia sp.

Serratia sp. Y-4 was isolated from soil. Many characteristics of the strain and optimum cultivation condition for protease production were investigated. The protease from Serratia sp. Y-4 was purified and studied for the properties of the enzyme. The isolated strain was identified to the genus Serratia. The strain was cultivated in 1%-casein, 0.5%-Na3PO4.7H2O, 0.1%-NaCl, 0.05%-KCl, 0.02%-MgSO4.7H2O, 0.02%-CaCl2.2H2O, 0.02%-ZnSO4.7H2O, 0.02%-MnCl2.4H2O and 0.5%-soy bean oil at pH 7.0 for 35 hrs. The enzyme was purified about 5.89 fold from the culture broth with 31.1% recovery and 19,613mc/mg through ultrafiltration, ammonium sulfate, DEAE-sephacel and Superose-12 chromatography. The purified enzyme was identified as one band by isoelectric focusing, SDS- and native-PAGE. It has maxium activity at 37oC and pH 9.0. Molecular weight of it is approx. 50 kD and pI is about 6.70. Its Km value for casein was 20mg/ml. 5 mM-EDTA, 5 mM-SDS, Ag+1, Cu+2, Hg+2 and Pb+2 inhibited the enzyme.