The effect of penicillin on CO2 production and the uptake of C14-labelled glucose and glutamine by Staphylococcus aureus.

Abstract

Radioactive glucose or glutamine was supplied to growing and non-growing cultures of Staphylococcus aureus 6538 in the presence of various concentrations of penicillin. Total CO2 and C14O2 production were measured, and the uptake and distribution of carbon from glucose and glutamine in both growing and non-growing cultures were determined. The production of CO2 from glucose was stimulated by penicillin, that from glutamine was suppressed, while total CO2 production was unaffected. Neither glucose nor glutamine were major substrates of respiration. Penicillin exerted widely different effects on the uptake and incorporation of carbon from both glucose and glutamine in growing and non-growing cells. From a consideration of these effects, it is suggested that penicillin affects cells at two or more specific points in their metabolism. It was noted that CO2 production continued at a high rate in non-growing cultures although cell division had virtually ceased.