EXTRACELLULAR ALKALINE PROTEINASE OF BACILLUS-INTERMEDIUS - ISOLATIONAND SOME PROPERTIES

An extracellular alkaline proteinase was isolated from the culture med ium of Bacillus intermedius 3-19. The enzyme was purified by ion-excha nge chromatography 200-fold, to apparent homogeneity (specific activit y 956 units/mg). The proteinase is maximally active at pH 10.0, 50 deg rees C and is equally stable over the pH range from 6.3 to 11.0. EDTA, o-phenanthroline, and p-chloromercuribenzoate have no affect on the a ctivity of the enzyme; phenylmethylsulfonyl fluoride inhibits it by 95 -97%. Thus, the B. intermedius enzyme is a subtilisin-like serine prot einase.