Effect of quaternary ammonium salts on energy-yielding and energy-requiring processes in Salmonella typhimurium.

The effect of 2-(dodecanoylamino) ethylalkyldimethyl-ammonium bromides on energy-yielding (respiration) and energy-requiring (biosynthesis of nucleic acids and proteins) processes in Salmonella typhimurium cells was studied. The quaternary ammonium salts represented a homologous series (n = 7). The efficacy of the compounds increased with the prolongation of the alkyl carbon chain up to octyl (C8), where the maximum was noted and then the efficacy decreased. This phenomenon known from the antimicrobial efficacy of these substances (cut-off effect) was shown also by influencing the rate of [14C]adenine and [14C]leucine incorporation and the inhibition of oxygen consumption (endogenous respiration). The tested compounds influencing these processes interfere with the energy metabolism of Salmonella typhimurium cells.