Archaeal transformation of metals in the environment.

We are becoming increasingly aware of the role played by archaea in the biogeochemical cycling of the elements. Metabolism of metals is linked to fundamental metabolic functions, including nitrogen fixation, energy production, and cellular processes based on oxidoreductions. Comparative genomic analyses have shown that genes for metabolism, resistance, and detoxification of metals are widespread throughout the archaeal domain. Archaea share with other organisms strategies allowing them to utilize essential metals and maintain metal ions within a physiological range, although comparative proteomics show, in a few cases, preferences for specific genetic traits related to metals. A more in-depth understanding of the physiology of acidophilic archaea might lead to the development of new strategies for the bioremediation of metal-polluted sites and other applications, such as biomining.