The accumulation of novobiocin by Escherichia coli and Staphylococcus aureus

The accumulation of novobiocin by Escherichia coli was shown to be a nonsaturable process. Inhibitors or uncouplers of respiration had no effect on accumulation in cells grown in Isosensitest broth, whereas, bacteria grown in nutrient broth demonstrated an energy-dependent efflux mechanism. In contrast, accumulation of novobiocin by Staphylococcus aureus was found to have a Km of 74 microM and uncouplers and inhibitors of respiration reduced the accumulation suggesting that in S. aureus novobiocin is transported actively.