PRODUCTION OF ALKALINE PROTEASE BY A NEW BACILLUS-SUBTILIS ISOLATE FOR USE AS A BATING ENZYME IN LEATHER TREATMENT

Bacillus subtilis, isolated from tannery waste, produced an alkaline p rotease at optimal activity when grown in a casein/gelatine medium in a stirred tank fermenter at 37 degrees C with the dissolved oxygen ten sion at 40% air saturation. Optimum protease activity (223 U ml(-1)) w as at pH 8.5 and was stable for 1 h up to 45 degrees C but at 60 degre es C lost 80% activity. Use of the crude protease as a bating agent fo r producing high quality leather is indicated. Tensile strength, burst ing strength, tear strength and elongation at break of prepared leathe r were increased with increasing amounts of protease used for bating.