Theczc operon ofAlcaligenes eutrophus CH34: from resistance mechanism to the removal of heavy metals

Summary The plasmid-borneczc operon ensures for resistance to Cd²⁺, Zn²⁺ and Co²⁺ ions through a tricomponent export pathway and is associated to various conjugative plasmids ofA. eutrophus strains isolated from metal-contaminated industrial areas. Theczc region of pMOL30 was reassessed especially for the segments located upstream and downstream the structural genesczc CBA. In cultures grown with high concentrations of heavy metals,czc-mediated efflux of cations is followed by a process of metal bioprecipitation. These observations led to the development of bioreactors designed for the removal of heavy metals from polluted effluents.