Influence of phosphonic acids and EDTA on bacterial copper toxicity

Eric D. van Hullebusch (1, 2) , Philippe Chazal (1) , Véronique Deluchat (1)

1 GRESE - Groupement de Recherche Eau, Sol, Environnement
2 LGE - Laboratoire Géomatériaux et Environnement

The influence of hydroxyethane-1,1′diphosphonic acid (HEDP) and aminotris(methylene) phosphonic acid (ATMP) on bacterial copper toxicity and comparisons with EDTA was studied. Two tests were used throughout the study, the normalised Microtox test and an assay (I24) based on Escherichia coli inhibition. The concentration range studied was mainly near the ones that are nowadays detected in the environment: 10-8-10-6M. A chemical approach was also performed in order to determine the speciation of the inhibitory copper forms in the working conditions used. Ligands lower copper toxicity after 10-6M, but protection by HEDP was lower than that of both EDTA and ATMP. For [ligand]/[copper] ratios close to 0.5 (with [ligand] > 10-6M), copper resistance increased in both tests in the presence of EDTA and ATMP but not in the presence of HEDP. For [ligand]/[copper] ratios close to 0.1 (with [ligand] = 10-7M) the presence of ATMP and EDTA seems to increase E. coli sensitivity to free copper.

Mots clés: Aminotris(methylene)phosphonic acid (ATMP); Hydroxyethane-1; 1' disphosphonic acid (HEDP); EDTA; Microtox; Escherechia coli; Copper toxicity

Domaines: Ingénierie de l'environnement

Eric D. van Hullebusch, Philippe Chazal, Véronique Deluchat. Influence of phosphonic acids and EDTA on bacterial copper toxicity. Toxicological and Environmental Chemistry, 2001, 82, pp.75-91. ⟨hal-00940178⟩