[Liberation of nuclease by cells of Staph aureus]

In supernatants of washed, resting cells of investigated strain, suspended in buffered solutions of adenine, adenosine, xanthosine and uridine, a nucleolytic activity was observed which was increasing during 3 hours of incubation at 37 degrees C. This activity was observed only in presence of determined concentration of these substances. Optimal concentration for liberation of nuclease activity in cell supernatants were: for adenine 0.2-0.4, adenosine 0.2, xanthosine-0.5 and uridine 0.3 mg/ml. Supernatants of cell suspensions were tested for presence of urease, an intracellular enzyme, which appears in the cellular environment only after disintegration of cells. Ureolytic activity in supernatants of cells suspended in solution of the above listed substances was not detected. These data exclude possibility of appearance of nucleolytic activity (nuclease) in supernatants as a result of cell disintegration and they indicate participation of adenine and some nucleosides in liberation of nuclease from cells.