Purification and Properties of Staphylococcal δ-Hemolysin I. Production of δ-Hemolysin

Abstract

Concentrated preparations of staphylococcal δ-hemolysin were obtained by growing selected hemolytic colonies from the 146P strain of Staphylococcus aureus on dialysis membranes laid over Brain Liver Heart agar plates at 37 C for 20 hr under 10% CO₂ and harvesting the growth from five such membranes in 1.0 ml of deionized distilled water. Incubation in a humid environment facilitated this harvesting procedure. Incubation longer than 40 hr or incubation under CO₂ higher than 10 to 20% gave lower yields of δ-lysin. Addition of a sugar, fermented by the organisms, resulted in lower yields of δ-hemolysin. Agar, although separated from the growing cells by the dialysis membrane, did potentiate δ-hemolysin production. Addition of 0.1% agar to the inoculum further enhanced this potentiation. δ-Hemolysin produced in broth or semisolid cultures was excessively diluted with the media. Dialysis membranes prevented this dilution and thus yielded concentrated preparations of δ-hemolysin.