ABSTRACT
Selenium is a micronutrient involved in diverse biochemical reactions [1] and has long been known to be required in the diet of animals and for the growth of plants. Indeed, a deficiency of dietary selenium in cattle results in deleterious effects, including anemia and death [2,3]. Selenium is required for the growth of several species of phytoplankton [4-6] and bacteria [7,8]. In contrast with its widespread use as a cofactor in biochemical systems, when absorbed at high concentrations selenium poses a threat to the health of animals [9,10], and selenium oxyanions (e.g., selenate and selenite) inhibit the growth of a variety of microorganisms [11-15].
