Toxicity of free and various aminocarboxylic ligands sequestered copper(II) ions to Escherichia coli.

Cytotoxicity of free Cu(II) ions and its complexes of EDTA, NTA or IDA in Escherichia coli (AB 4401) wild type cells were assessed by cell inactivation assay. In order to understand the toxic effects of these additives, membrane status by AFM vis-à-vis K(+) ion efflux were followed in the absence and in the presence of Cu(II) ions or its complexes. This was coupled with the determinations of cellular copper concentrations by atomic absorption spectrometry.