The uptake of cetyltrimethylammonium bromide by Escherichia coli

THE uptake of cetyltrimethylammonium bromide (CTAB) by bacteria has previously been examined by Salton (1951) and by McQuillen (1950). Both workers determined its concentration in solutions by titration with sodium cetyl sulphate using pinacyanol bromide as indicator, and reported that uptake was in the form of a typical adsorption isotherm with saturation of the cells at an uptake equivalent to several theoretical close packed monolayers. This communication reports on studies of the uptake of 14C-labelled CTAB by cells of Escherichia coli and the concurrent release of phosphorus compounds from their metabolic pool.