Purification and characterization of extracellular protease from Bacillus subtilis ATCC 6633
1996
Mubarik, N.R. (Institut Pertanian Bogor, Bogor (Indonesia)) | Wirahadikusumah, M.
Extracellular protease excreted by Bacillus subtilis ATCC 6633 was isolated at 10 hours of its fermentation time in the medium modified by Horikoshi. Crude protease was purified through 30-50 percent cold acetone, dialysis, followed by gel filtration chromatography using Sephadex G-75. Two proteases were identified, 1.e. metallo protease and mixed protease of metallo and serine protease. The optimum conditions of metallo protease activity occured at 40 degree C, pH 8.0, 25 minutes incubation, and at 40-45 degree C, 20 minutes incubations, pH 8.0-8.5, for mixed protease. Kinetic study of metallo protease indicated that it had Km (Michaelis-Menten Constant) 1.721 percent and Vmax (maximum activity) 173.31 unit/mg/25 minutes. The inhibition reaction kinetic of metallo protease indicated the type of mixed inhibition which showed a slope at Km approximate 1.109 percent and Vmax approximate 110.86 unit/mg/25 minutes when challenged with inhibitor
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