Enzyme preparations of Staphylococcus aureus were examined for their ability to solubilize (32)P-labeled cell walls of the parent organism. Enzymatic activity was observed in the growth medium, in soluble fractions, and associated with native cell walls. Enzyme associated with isolated cell walls could be inactivated with formaldehyde without reducing the… (More)
FIG. 1. Time course of appearance of cell-wall lytic activity in various cell fractions during growth of Staphylococcus aureus. An inoculum of 100 ml of an overnight shake culture of S. aureus in Trypticase Soy Broth wasplaced in 1,000 ml offresh medium in a 2-liter flask. Shaking was continued and, at hourly intervals, a 250-ml sample ofmedium was removed. Optical density was measured at 660 mMu (C). The cells were centrifuged for 20 min at 5,800 X g. The supernatant fraction = "culture medium." The cells were resuspended in 25 ml ofwater and centrifugedfor 10 min at 35,000 X g. The supernatant fraction = "wash of cells." The cells were resuspended to 25 ml with water and frozen overnight. Cells were thawed and centrifuged for 10 min at 35,000 X g. The supernatant fraction = "freeze-thaw extract." The cells were resuspended to 36 ml and disruptedfor 5 min with the Braun disintegrator in the presence of44 g of glass beads. The cell walls were centrifuged for 1(l min at 35,000 X g. The supernatant fraction = "Braun super." Enzyme activity was measured under standard' assay conditions. Activity in the culture medium (0); wash of cells (0); freeze-thaw extract (O); Braun super (A) were corrected to the total activity in the, original 250-ml sample.