THE EFFECT OF CERTAIN ANTIBIOTICS ON THE FORMATION OF AN ADAPTIVE ENZYME IN STRAIN OF PSEUDOMONAS AERUGINOSA

¹ Department of Physiology and Pharmacology, Duke University School of Medicine, Durham, North Carolina

1. Incubation of washed cells of a strain of Pseudomonas aeruginosa with different concentrations of succinate apparently causes the formation of a cell constituent(s) which can subsequently be utilized directly or indirectly for the synthesis of an enzyme which oxidizes benzoic acid. Within a certain range the amount of the constituent formed, as measured by the subsequent oxidation rate of benzoic acid, is proportional to the amount of succinic acid oxidized.

2. By the addition of certain drugs before or after the succinic acid has been oxidized the relative inhibitions of the formation and utilization of the constituent were determined. Terramycin and Aureomycin are probably almost equally effective on formation and utilization, streptomycin more effective on the former. Chloramphenicol and arsenite are apparently more effective on utilization.

3. In the concentration used the drugs do not inhibit the oxidation of succinic acid. Their effect on the formation or utilization is not dependent on the succinic acid concentration.