[Characterization of the thio-dependent hemolysin of Bacillus alvei].

Bacillus alvei hemolytic toxin has been characterized in five main steps from a 18 hours culture supernatant fluid. 50% ammonium sulfate precipitations are followed by Sephadex gel filtrations. After that we proceed to an isoelectric focusing in a narrow pH gradient (from 4 to 6). A final step consists in a gel filtration allowing to separate sucrose and ampholins from toxin preparation. The homogeneity of the alveolysin preparation is controlled on double immunodiffusion, immunoelectrophoretic analysis and polyacrylamid gel electrophoresis. From this study we can conclude that B. alvei hemolysin has a molecular weight of 45,000 and an isoelectric point of 5.1. 80 ng/HU of cholesterol represent the 50% inhibitory dose for the hemolytic activity of the alveolysin. Lethal dose calculated on mice is found to be 300 HU.