Gluconate Metabolism in Escherichia coli

Abstract

On the basis of information available in the literature, gluconate dissimilation in E. coli is 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 Cl4-labeled gluconate or glucose, distribution of Cl4 in the carbon atoms of pyruvate formed from specifically labeled C14-glucose and C14-gluconate, and the ability of cell-free extracts to produce pyruvate from 6-phosphogluco-nate. 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 E. coli and other bacterial species is discussed.