Abstract
The lysis of group A hemolytic streptococci by extracellular enzymes of Streptomyces albus has been studied. The most favorable material for fractionation of the lytic enzymes was obtained by surface growth on shallow layers of liquid medium containing an acid hydrolysate of casein, glucose, and salts. The results of fractionation experiments show that the potent proetolytic enzyme of Streptomyces albus is not able to lyse group A streptococci, and that the initiation of lysis is dependent upon the action of a second, non-proteolytic enzyme. The nature of the non-proteolytic enzyme has not been determined. It does not appear to be a ribonuclease or a lysozyme-like enzyme.