INTRACELLULAR HEMOLYSIN OF PSEUDOMONAS AERUGINOSA.

Berk, Richard S. (Wayne State University, Detroit, Mich.). Intracellular hemolysin of Pseudomonas aeruginosa. J. Bacteriol. 85:522-526. 1963.-Disruption of cells (2 to 6 days old) of Pseudomonas aeruginosa grown in Tryptose Broth devoid of blood yielded an intracellular hemolysin active on sheep and human erythrocytes. The intracellular agent was not usually detectable in cells grown under highly aerobic conditions. However, activity was observed after 48 hr of growth and appeared to reach a peak at 96 hr when grown under static conditions. Centrifugation of hemolytic extracts at 20,000 x g for 30 min resulted in a fractionation of activity into particulate and soluble components. Similar fractionation of activity occurred after adjustment of the pH of crude extracts to 1.40. In addition, hemolytic preparations were not inactivated by boiling for 90 min, by treatment with ethylenediaminetetraacetate, or by heating in equal volumes of 20% KOH. Activity over a wide pH range was noted, with a maximum occurring at approximately 6.0. However, some preparations occasionally exhibited a second peak on the alkaline side.