title: Effect of metallic cations on the viability of phenol-treated Escherchia coli.
abstract: Five metallic cations (Fe(3+), Cr(3+), Ca(2+), Mg(2+), Mn(2+); concentration range, 1.85 x 10(-4) to 37 x 10(-4)m) were incorporated individually as chlorides into nutrient broth and agar media used for the recovery of phenol-treated Escherichia coli. The effects observed varied with the concentration and the ionic species. In nutrient agar, Fe(3+) and Cr(3+) were generally beneficial but were toxic at 37 x 10(-4)m. Of the divalent ions tested, Ca(2+) and Mg(2+) usually gave higher counts in nutrient broth, except at a concentration of 9.25 x 10(-4)m, whereas the effect of Mn(2+) was rather variable. Two possible explanations are suggested to explain these effects. Toxic materials may be removed from the media by the precipitates formed on the addition of Fe(3+) or Cr(3+), or, in the case of the divalent ions, the integrity of the bacterial cell membranes may be maintained.
mesh_terms: D002118:Calcium / Q000494:pharmacology; D002462:Cell Membrane / Q000187:drug effects; D002857:Chromium / Q000494:pharmacology; D004926:Escherichia coli / Q000187:drug effects*; D007501:Iron / Q000494:pharmacology; D008274:Magnesium / Q000494:pharmacology; D008345:Manganese / Q000494:pharmacology; D008670:Metals / Q000494:pharmacology*; D010636:Phenols / Q000494:pharmacology*
chemical_list: D008670:Metals; D010636:Phenols; D002857:Chromium; D008345:Manganese; D007501:Iron; D008274:Magnesium; D002118:Calcium