Mechanisms of bacterial degradation of arsenic

Abstract

Arsenic is a toxic metalloid that exists in two major forms (arsenate and arsenite). The anthropogenic activities of man are its major source in the environment. Bacteria have developed resistance against arsenic by using detoxification mechanisms such as oxidation of arsenite to arsenate with the aid of an enzyme arsenite oxidase and in the process gain energy, reduction of arsenate to arsenite through phosphate transporters by a reductase enzyme arsenate reductase and methylation of arsenite with the enzyme S-adenosylmethionine methyltransferases (SAM). The ars operon which mediates the extrusion of arsenic out of bacterial contains a three and five gene operon that assist bacterial with arsenic resistance respectively. Keywords: Arsenic, Arsenate, Arsenite, Arsenate reductase, Arsenite oxidase, Phosphate transporters, Bioremediation.