Abstract:

WT5BZ]A Gram negative marine bacterium Ar/W/b/75°25′N/1 producing extracellular alkaline protease was isolated in Arctic. The bacterium could grow at the range of temperature from 7 to 30℃, and grew better at 30℃,but it could not grow at 40℃. Keeping certain salinity concentration in medium was necessary for bacterium's growth for its some halophilic character. The bacterium could grow well in medium containing salinity concentration from 0.5% to 10% sodium chloride. Glucose, sucrose and soluble starch could be utilized by the strain, and among them glucose was the optimal carbon source for growth of the bacterium. Peptone was the optimal organic nitrogen source for growth and protease producing of the strain, and ammonium nitrate was the optimal inorganic nitrogen source. About 75.7% of total protease of the strain were extracellular enzyme. Optimal temperature for proteolytic activity was 40℃, and the thermal stability of protease kept stable when temperature wasn't higher than 40℃. Protease of the strain showed high proteolytic activity from pH 7 to pH 11, its optimal pH was 8. [WT5HZ]