Studies on protease from marine bacteria. 1 Isolation of marine Pseudomonas sp 145-2 and purification of protease.

Marine Pseudomonas strain 145-2 having the ability to produce extracellular protease was isolated from Uwa sea water, Ehime prefecture in Japan. This strain grows at 0 degrees - 37 degrees C, but protease production was observed only during 6-10 h cultivation at 20 degrees - 30 degrees C, when casein, as the nitrogen and carbon source in a concentration of 0.5-1.0%, was used. Maximum production of protease by the strain was also observed. Na, K, Ca and Mg ions were needed for growth and production of protease. Two extracellular proteases (proteases I and II) were purified from the culture supernatant by ammonium sulphate fractionation following Sephadex gel chromatography. Protease I had a larger molecular weight than protease II. After purification, proteases I and II were revealed as homogeneous by acrylamide gel electrophoresis and immunoelectrophoresis.