MECHANISM OF BACTERICIDAL ACTION OF PHENETHYL ALCOHOL IN ESCHERICHIA-COLI

The mechanism of bactericidal action of phenethyl alcohol (PEA) in E. coli, which was previously demonstrated to be dependent on protein syn thesis, has been investigated. Mutants resistant to PEA were selected, but the resistance observed was associated with a change in permeatio n. PEA effects on DNA, RNA, and protein synthesis were studied with ba cteriostatic and bactericidal concentrations. Similar results (inhibit ion of DNA synthesis and decrease in RNA synthesis) were obtained with lethal concentrations of PEA in cells pretreated with chloramphenicol , and with bacteriostatic concentrations of PEA in unpretreated cells. The PEA intracellular accumulation reached a maximum within 4 min and was not inhibited by KCN or by 2,4-dinitrophenol. The presence of phe nylacetaldehyde was demonstrated in both stationary and exponential gr owth phase cells exposed to PEA but not in cells pretreated with chlor amphenicol. These results suggested that the bactericidal mechanism of action of PEA involves its conversion into the corresponding aldehyde .