METABOLISM OF 2-PYRROLIDONE AND γ-AMINOBUTYRIC ACID BY PSEUDOMONAS AERUGINOSA

Abstract

A strain of P. aeruginosa was isolated by elective culture from garden soil and found to utilize 2-pyrrolidone as a sole source of C and N. Ability of the organism to utilize this substance appears to be adaptive; by use of a simultaneous adaptation method, [gamma] -aminobutyric acid has been implicated as the hydrolytic breakdown product of 2-pyrrolidone. An active [gamma] -aminobutyric-glutamic transaminase was found in cell-free preparations of P. aeruginosa. The transaminase appears to be specific for [gamma] -aminobutyric acid and [alpha]-ketoglutaric acid. When subjected to prolonged dialysis, loss of enzyme activity occurred; the loss was not restored by addition of pyridoxal phosphate. The transaminase was inhibited by hydroxylamine hydrochloride and cell-free enzyme preparations from cells grown in the presence of an inhibitory level of isoniazid were stimulated by pyridoxal phosphate.