The Bacteriostatic Action of Phenol, Benzoic Acid and Related Compounds on Bacterium aerogenes

Abstract

Using a mass inoculation technic and spectrophoto-metric measurements to study inhibition during the logarithmic growth phase the following 10 compounds were tested: Phenol, catechol, resorcinol, benzoic acid, o-, m- and p-hydroxybenzoic acids, methyl p-hydroxybenzoate, resorcyclic acid and p-rotocatechuric acid. An approx. inverse relationship between potency and water solubility was demonstrated within the phenols and the acids considered separately. Compounds with an ortho-relationship between hydroxyl and carboxyl groups are more potent than those with meta and para relationships. An hypothesis that inhibition is proportional to adsorption of inhibitor molecules is used to account for the the potency of the different chemical groups.