Antimicrobial Effect and Disappearance of Sodium Nitrite in Staphylococcus aureus Cultures

Staphylococcus aureus was sensitive to as little as 100 μg sodium nitrite (NaNO 2 )/mL under strictly anaerobic conditions at pH 7.3 and was more sensitive at pH 6.0. S. aureus was less sensitive to NaNO 2 in the presence of 1.0‐1.5 μg O 2 /mL. NaNO 2 disappeared during growth of S. aureus. Disappearance was greater in the system containing 1‐1.5 μg‐O 2 than in strictly anaerobic cultures at an initial pH of 7.3 or 6.0. Nitrite reductase activity was not detected in either soluble or membrane fractions of S. aureus. Interaction of NaNO 2 with secreted metabolic products, dismutation of NaNO 2 by reduced pH and adsorption of NaNO 2 to S. aureus cells were not involved in the disappearance of NaNO 2 . Nitrite, nitric oxide, nitrous oxide and ammonia were not end products of NaNO 2 disappearance.