Precious Metals and Living Organisms

Abstract

In principle, the biosphere contains the essential minerals necessary for growth, survival and multiplication of the diverse spectra of living organisms, as well as all of the remaining naturally occurring elements of the Periodic Table. Here we emphasize the concept of selective element accumulation characteristically displayed by individual species from all of the major taxonomic groups. In particular, we describe the range of organisms and tissues known to contain relatively large concentrations of precious metals, including gold, silver, platinum and iridium. These accumulator species may indeed be detected in various natural habitats as well as on contaminated and polluted sites. Specific examples, drawn from a variety of life science disciplines, are presented to illustrate the possible involvement of organisms in precious metal cycling and biogeochemical deposition over geologic time. The prospects for metal recovery from fresh and ocean water utilizing specific organisms is also assessed. The metabolism of precious-metal-containing drugs is outlined with reference to the mechanisms of action of compounds at the cellular level that give these compounds considerable potential in therapeutic applications. It is concluded that the accumulation of precious metals by organisms is little understood and merits further research.