The copper-resistant bacterial strain Achromobacter insolitus LCu2 was selected as a model for studying bacterial resistance to heavy metals mediated by efflux proteins. Nine gene clusters of RND efflux systems, potentially responsible for heavy metal export from the cell and related to the previously described bacterial efflux systems, were identified in the strain LCu2 genome. Experimental studies demonstrated resistance of A. insolitus LCu2 to cadmium, zinc, chromium, and lead cations; its moderate tolerance to cobalt and nickel; and its sensitivity to silver cations. These results are important for further study of the genetic and metabolic mechanisms of bacterial resistance to heavy metals.
Burygin et al. (Mon,) studied this question.