Effect of 2-phenoxyethanol upon RNA, DNA and protein biosynthesis in Escherichia coli NCTC 5933

The effects of concentrations of 2-phenoxyethanol of negligible bactericidal activity upon the rates of biosynthetic assimilation by Escherichia coli, of 14C-thymidine, 14C-uracil, 14C-phenylalanine and 14C-glucose, were assessed. Increasing the drug concentration from 0.05-0.4% w/v progressively increased inhibition of growth rate, measured as changes in optical density. Thymidine, uracil and glucose assimilation were inhibited to an extent similar to growth rate, whilst phenylalanine incorporation was markedly less sensitive at the lower concentrations (leads to 0.2% w/v). In addition to its previously observed roles in inhibiting oxidative phosphorylation and TCA cycle enzymes, it is suggested that 2-phenoxyethanol can exert a more direct inhibitory action upon DNA and RNA biosynthesis and possibly on protein biosynthesis.