Effect of sodium chloride on the activity and production of staphylococcal exonuclease

Extracellular nuclease activity in Staphylococcus aureus was enhanced about fourfold by 1% (w/v) NaCl, KCl, CsCl or LiCl. The pH and concentration of Ca2+ for optimum activity varied with the NaCl concentration; with an increased NaCl concentration, a higher Ca2+ concentration and a lower pH were required. Vmax, but not Km, varied with the concentration of NaCl. The addition of 3% (w/v) NaCl to growing cultures of S. aureus increased nuclease production fivefold.