[Metal resistance systems in Pseudomonas].

Several chromosome- and plasmid-encoded metal resistance genetic systems have been studied in Pseudomonas and related bacteria. Some systems are known with molecular detail whereas others are still poorly understood. The former include resistance genes for cations derived from mercury, cadmium and copper and anions from arsenic and chromium. Except for mercury, where a redox transformation occurs, extrusion of the toxic ions from the bacterial cytoplasm appears to be the most common mechanism of resistance.