Microbial Management of Cadmium and Arsenic Metal Contaminants in Soil

Abstract

Contamination of soil with heavy metals poses a major environmental and human health problem. Of the various metals, cadmium and arsenic are the two well-known heavy metals. The toxic effects of these metals are due to their abundance while nonbiodegradable nature leads to their concentration buildup in soil. Microbial methods of environment purification and cleanup are promising because of the safety, efficiency, and cost effectiveness. A number of microorganisms including members of Archea, Eukarya, and Bacteria are resistant to cadmium and arsenic and have evolved several defense mechanisms to overcome metal toxicities. The bioremediation of cadmium- and arsenic-contaminated soil involves active microbiological processes, such as biosorption, bioaccumulation, sequestration, and efflux. Furthermore, knowledge of metal ion resistances could provide important insights into environmental processes and help in understanding the basic living processes.