Production and Purification of the Gamma Haemolysin of Staphylococcus aureus ‘Smith 5R’

SUMMARY: The gamma haemolysin of Staphylococcus aureus ‘Smith 5R’ was produced on Dolman-Wilson agar overlain with cellophane. Maximal yields of crude lysin with titres of 2000 to 4000 haemolytic units/ml were obtained within 24 h at 37 °C in 10 % (v/v) CO2 in air, on medium adjusted to pH 7.0.

The crude lysin was purified 2700-fold (with 75 % recovery) by ultrafiltration, gel filtration and ammonium sulphate fractionation. The specific activity of the lysin was 105 haemolytic units/mg protein after the dialysed active precipitate was extracted with NaCl and reprecipitated with ammonium sulphate. Purified gamma lysin was homogeneous by disc electrophoresis and immunoelectrophoresis.