Effect of organic ammonium salts on metabolic processes in Pseudomonas aeruginosa

The effect of a homologous series of 2-(dodecanoylamino)-ethylalkyl-dimethylammonium bromides on the cell metabolism of a Pseudomonas aeruginosa strain isolated from a nosocomial infection was studied. The inhibition of the incorporation of radioactive precursors into macromolecules (DNA, RNA, proteins) was dependent on the length of the alkyl chain of the tested substances. Similar results were noted also by following the inhibition of the endogenous respiration of P. aeruginosa. The most effective substance at suppression of [14C] precursors incorporation was with hexyl, and in the case of respiration, the substance with octyl in the molecule. The total inhibition of the respiration in the presence of exogenous carbon substrates, i.e. glucose and glycerol, was found with the substance containing the octyl group (conc. 100 micrograms/ml). We assumed that the studied substances interfere with cell energy-carbon metabolism of P. aeruginosa.