Copper resistance in bacteria.

Copper is a required trace element for many organisms, yet it can exert an inhibitory effect on bacterial growth at relatively low concentrations. However, there are some bacterial species that can tolerate high levels of copper. It also has been reported that copper resistance is plasmid-encoded in Escherichia coli, Proteus vulgaris and a Pseudomonas syringae isolate. It is not known if copper is effluxed from the cell, detoxified by binding to copper-binding proteins, or binds to cell-surface components. Actual data on copper transport in bacteria is also lacking, indicating that this area of research deserves serious attention.