Thiolutin inhibits utilization of glucose and other carbon sources in cells of Escherichia coli

Thiolutin was found to inhibit the utilization of glucose and other growth substrates in Escherichia coli. The inhibition was detected by a sharp drop of the respiration rate after addition of the antibiotic. The actual function affected was allocated to the cytoplasmic membrane of the bacterial cells by the following evidence: --spheroplasts were affected like intact cells, --individual reactions of either the electron transport chain or the glycolytic pathway were not inhibited, --glucose consumption in the culture stopped and the cells accumulated guanosine tetraphosphate as under starvation conditions, --activation of the cell's apo-glucose dehydrogenase restored respiration via bypassing the glucose phosphotransferase system. It was concluded that the transport of certain substrates across the membrane was inhibited.