Metallotolerants are extremophiles that are able to survive in environments with a high concentration of dissolved heavy metals in solution. Metallotolerants may be found in environments containing arsenic, cadmium, copper, and zinc. Known metallotolerants include Ferroplasma sp. and Cupriavidus metallidurans.
Metallotolerants adapt to their environment by reducing energy loss by excreting less.
References
Metallotolerant Wikipedia(Text) CC BY-SA