Inhibitory effect of Li+ on cell growth and pyruvate kinase activity of Escherichia coli

Li+ inhibited growth of Escherichia coli when glucose, galactose, fructose, or glycerol was added as the sole source of carbon. Growth inhibition was not observed when lactate or a mixture of amino acids was used as the carbon source. A mutant possessing elevated activity of Li+ extrusion was not inhibited by Li+. These results suggested that intracellular Li+ inhibited the glycolytic pathway, most likely triose metabolism, without affecting gluconeogenesis. We also found that pyruvate kinase I was inhibited by Li+.