The effect of 14 arginine analogues on the growth of Pseudomonas aeruginosa in a liquid mineral medium with either L-glutamate or L-ornithine as the sole carbon and nitrogen source was investigated. Two analogues, L-indospicine and L-arginine hydroxamate, inhibited growth markedly. The former was most effective in the or-nithine medium and the latter only in the glutamate medium.
The inhibition by arginine analogues of the first two enzymes of the arginine pathway, N-acetylglutamate synthetase and N-acetylglutamate 5-phosphotransferase, was studied. It was found that inhibition of these two feedback-sensitive enzymes did not correlate with inhibition of growth. O-(L-norvalyl-5)-isourea, which was a rather weak inhibitor of growth, was at least three times more active as an inhibitor of the enzymes than L-indospicine and L-arginine hydroxamate. These two analogues were about ten times less effective than L-arginine, the strongest inhibitor of both enzymes.