OCCURRENCE OF COP-LIKE COPPER RESISTANCE GENES AMONG BACTERIA ISOLATED FROM A WATER DISTRIBUTION-SYSTEM

The occurrence of cop-like copper resistance determinants homologous t o the cop genes of Pseudomonas syringae among bacteria isolated from a water distribution system experiencing copper corrosion was investiga ted in this study. It was found that at least 49% of the copper-resist ant bacteria and less than 15% of the copper-sensitive isolates posses sed a cop homolog. The occurrence of this determinant in the copper-re sistant population correlated with the degree of copper tolerance exhi bited by the bacteria. The effect of organic substances present in the culture media on the empirical degree of bacterial copper tolerance i s also discussed.