FORMATION OF HEMOLYSIN BY STRAINS OF PSEUDOMONAS AERUGINOSA

Hemolysin is formed in sonic extracts of cells of Pseudomonas aeruginosa by the action of a heatlabile substance, probably an intracellular release enzyme, on a substrate from the disrupted cell. The substrate and most of the hemolysin released can be sedimented by highspeed centrifugation. Hemolysin-negative strains appear to possess no release enzyme but do contain the substrate, because addition of particulate matter to extracts of hemolysin- positive cells increases the rate and extent of hemolysin formation. The rate of hemolysin release in sonic extracts is strongly influenced by the concentration of the two reactants and minor dilution abolishes all activity. There is only a small amount of release enzyme and substrate present in 24-hour cells but increasingly greater amounts appear in extracts of 48- and 72-hour cells.