EXTRACELLULAR PROTEASES FROM STREPTOMYCES SPP. G(157) - PURIFICATION AND CHARACTERIZATION

While investigating about 250 strains of actinomycete isolated from ta nnery soil, Streptomyces spp. G(157) exhibited the highest potency for the production of extracellular proteases. After preliminary fraction ation by differential precipitation with (NH4)(2)SO4 the purification was carried out on a Sephadex G-100 gel-filtration column. Two proteol ytically active fractions, fractions 1 and 2, were obtained, The two f ractions were further purified on a DEAE-cellulose ion-exchange column . Upon characterization, fraction 1 was found to be a metal-chelator-s ensitive protease and fraction 2 a trypsin-like protease, The metal-ch elator-sensitive protease was found to have a pH optimum over the rang e 7.0-8.0, a temperature optimum between 45 and 55 degrees C and molec ular mass of 36 kDa, The trypsin-like protease was found to have a pH optimum between 8.4 and 8.6, a temperature optimum of 37 degrees C and molecular mass of 21 kDa.