METABOLISM OF PYRUVATE AND GLUCOSE BY INTACT-CELLS OF HELICOBACTER-PYLORI STUDIED BY C-13 NMR-SPECTROSCOPY

The metabolic routes of substrate catabolism by intact cells of H. pyl ori have been investigated by C-13 NMR. Real time analyses of metaboli c transformations under anaerobic conditions have been obtained with d ense cell suspensions incubated with C-13-labelled pyruvate and glucos e. In addition, time point studies have been carried out with cells in cubated under aerobic conditions. Anaerobically, pyruvate was rapidly metabolized to lactate, ethanol and acetate. In addition, alanine was produced in significant quantities by cells provided with a nitrogen s ource and the metabolic incorporation of nitrogen from urea was demons trated. Under aerobic conditions acetate was the major oxidation produ ct from pyruvate; no evidence was obtained for tricarboxylic acid cycl e activity. Glucose was metabolized more slowly than pyruvate. Anaerob ically, two major products were observed and identified as sorbitol an d gluconate by gas chromatography/mass spectrometry. Evidence was obta ined for the oxidation of glucose to acetate under aerobic conditions. The fate of the C-13 label with glucose substrates labelled in differ ent positions showed that this oxidation takes place via the Entner-Do udoroff pathway.