Eagon, R. G. (University of Georgia, Athens). Pyridine nucleotide-linked reactions of Pseudomonas natriegens. J. Bacteriol. 84:819–821. 1962—The observation that Pseudomonas natriegens utilizes the Embden-Meyerhof pathway and the hexose monophosphate-pentose cycle only very slightly, even though the necessary enzymes are present, was explained by the existence of a sluggish system for the oxidation of reduced triphosphopyridine nucleotide (TPNH). Pyridine nucleotide transhydrogenase could not be detected in cell-free extracts. A very active system for the oxidation of reduced diphosphopyridine nucleotide (DPNH) was observed. Thus, since lactic acid is a major end product of glucose dissimilation and since the lactic dehydrogenase of P. natriegens does not utilize DPNH as cofactor, the Embden-Meyerhof pathway apparently operates aerobically by direct oxidation of DPNH, presumably by coupling with the terminal oxidase system rather than by coupling to synthetic reactions requiring DPNH as cofactor. A TPNH-specific glutathione reductase was detected which was inhibited by adenosine-2′-monophosphate.