Abstract
Two menaquinone-deficient and one aromatic-deficient mutants of Staphylococcus aureus were unable to reduce nitrate to nitrite. Reinitiation of menaquinone synthesis in the aromatic-deficient mutant by growing it with shikimic acid restored its nitrate respiratory activity. The results clearly demonstrate a role for menaquinone in nitrate respiration in Staphylococcus aureus.