Bacteriolysis and inhibition of gram-positive bacteria by components of Streptococcus zymogenes lysin

The ability of the A and L components of Streptococcus zymogenes lysin to cause lysis or to inhibit growth of a variety of gram-positive bacteria has been examined. Frank lysis of some, but not all, strains of S. faecalis, S. faecium, and S. liquefaciens by L component alone was demonstrated. None of the strains of these species was lysed by A component alone. S. durans was not lysed by either component. Inhibition of growth of all enterococcal strains by both A substance-producing and L substance-producing mutants of S. zymogenes was also demonstrated. However, inhibition by the A substance producer was markedly less than by the L substance producer. Inhibition of the growth of a number of other gram-positive genera by both A and L mutants was also noted.