Bacteriocin of a group A streptococcus: partial purification and properties.

The production of bacteriocin-like inhibition by certain strains of group A streptococci was demonstrated during the growth of these organisms on solid nutrient media. Active bacteriocin could not be recovered from broth cultures, possibly because of its inactivation by streptococcal proteinase. The bacteriocin, streptocin A, produced by Streptococcus pyogenes strain FF-22 was partially purified by chemical precipitation and chromatography on carboxymethyl-cellulose. Streptocin A inhibited the growth of various gram-positive organisms but none of a wide range of different gram-negative strains. The bacteriocin was inactivated by proteolytic enzymes and, although labile in alkali, it was extremely stable to heating in mild acids.