Gluconate Metabolism in Escherichia coli

On the basis of information available in the literature, gluconate dissimilation in Escherichia coliis thought to occur via the hexose monophosphate pathway. Evidence is presented in this study that gluconate is catabolized in this organism via an inducible Entner-Doudoroff pathway. This evidence is based on chromatographic examination of end products produced from 14C-labeled gluconate or glucose, distribution of 14C in the carbon atoms of pyruvate formed from specifically labeled 14C-glucose and 14C-gluconate, and the ability of cell-free extracts to produce pyruvate from 6-phosphogluconate. Degradation of gluconate by an Entner-Doudoroff pathway occurred simultaneously with a glycolytic cleavage of glucose. A relationship between gluconate-induced, Entner-Doudoroff pathway activity and catabolism of glucose in Escherichia coliand other bacterial species is discussed.