Concern over our increasingly polluted environment, with its potentially deleterious effects on organisms, including humans, has sparked considerable research into the strategies by which living systems contend with toxic compounds. One area of research that has been especially prolific in recent years deals with the mechanisms by which bacteria cope with increased heavy metal burdens. Heavy metals are prevalent throughout the biosphere, and while some (e.g., Co, Cu, Mo, Ni, and Zn) are required in trace amounts, elevated concentrations of most are deleterious by virtue of their avid ligation to cellular components, particularly proteins. Especially toxic to higher organisms are organometallics, whose lipophilic nature gives them a
strong tendency toward bioaccumulation in the food chain
