ALKALINE PROTEASE, ITS PRODUCTION, ITS USAGE AND MICROORGANISM PRODUCING THE SAME PROTEASE

摘要

PURPOSE:To provide the subject new enzyme exhibiting an excellent stability in a liquid detergent component or in a detergent solution containing a low- concentration surfactant in the washing and capable of efficient and low-cost supply. CONSTITUTION:An alkaline protease. Action: hydrolysis of proteins; optimum pH: pH11 to 11.5 when allowed to act on casein as a substrate at 30 deg.C for 10min; optimum temperature: about 60 deg.C when allowed to act on casein as a substrate at pH10; thermal stability: If treated at 55 to 57 deg.C and at pH10 for 10min, the activity is reduced by half; molecular weight: 2900+ or -2000 (SDS polyacrylamide electrophoresis method). This enzyme can be obtained by culturing a Bacillus microorganism producing the alkaline protease, its artificial mutant or its artificial gene-recombinant strain [e.g. a new strain SD 523 (FERM-P-12113) belonging to Bacillus firmus] in a culture medium and subsequently collecting it from the resultant culture solution. The culture is carried out preferably in an aerobic condition, at initial pH of 9 to 10, culturing at pH8.5 to 10 and at 30 to 37 deg.C.