ARS | Publication request: ENZYME-MEDIATED TRANSFORMATIONS OF HEAVY METALS/METALLOIDS

Submitted to: Book Chapter
Publication Type: Book/Chapter
Publication Acceptance Date: June 21, 2002
Publication Date: December 1, 2002
Citation: DUNGAN, R.S., FRANKENBERGER, W.T. ENZYME-MEDIATED TRANSFORMATIONS OF HEAVY METALS/METALLOIDS. BOOK CHAPTER. 2002.

Technical Abstract: A major emphasis has been placed on the bioremediation of organic compounds and their fate and transport throughout the environment. However, another important class of chemicals polluting our environment are inorganic, particularly heavy metals and metalloids. Heavy metals are elements of the Periodic Table with a density of more than 5 g cm-3. While this encompasses a large percentage of the metals, only several heavy metals/metalloids are regarded to be of environmental concern including selenium (Se), arsenic (As), chromium (Cr), and mercury (Hg). In the U.S., more than 50% of the National Priority (Superfund) sites ranked on the National Priorities List (NPL) contain heavy metals which are designated as a threat or problem to the environment. Since heavy metals/metalloids cannot be degraded (i.e., biologically or chemically) they are among the most intractable pollutants to remediate. The purpose of this chapter is to review microbially mediated transformations of Se, As, Cr, and Hg and discuss, where applicable, how they are currently being applied in bioremediation approaches to detoxify soils and waters.