Starved cells of a glucose-grown strain of Staphylococcus aureus are resistant to the action of staphylococcin 1580. Reinitiation of sensitivity is readily obtained upon the addition of glucose, but only weakly with L-lactate, although the latter induces higher ATP levels and supports L-glutamic acid uptake better than glucose does. The NADH/NAD+ ratio correlates with the staphylococcin sensitivity. 2. Starved pyruvate-grown cells remain partially susceptible and full sensitivity is restored both in the presence of glucose and L-lactate. 3. Arsenate but not dicyclohexylcarbodiimide (DCCD) blocks the reinitiation of sensitivity in the presence of glucose. Both arsenate and DCCD block sensitivity in the presence of L-lactate. 4. Aerobically grown cells are sensitive to staphylococcin 1580 under anaerobic conditions. Anaerobically grown cells are less susceptible, but sensitivity can be restored by glucose and also by L-lactate plus nitrate when cells are previously induced for nitrate reductase. 5. Starved cells of a mutant strain defective in the maintenance of a high-energy state of the membrane are normally sensitive in the presence of glucose, but resistant in the presence of L-lactate. A strain lacking a functional respiratory chain (men-) is also sensitive with glucose but resistant in the presence of L-lactate. 6. It is concluded that the initiation of the staphylococcin 1580 action is under control of a mechanism regulating the energy flow in the cell, and involving the presence of a high-energy phosphorylated compound.
