Microorganisms role in the bioremediation of contaminated soils with heavy metals

Abstract

Heavy metal pollution is a worldwide problem that affects human health. Metals are non-degradable elements that move through the biosphere by changes in its redox state. Considering its toxicity and abundance, the most studied heavy metals are mercury, arsenic and lead. In soils heavy metal toxicity is due to fraction that is available to organisms. This fraction is determined by the physicochemical characteristics of the soil (pH, redox potential and organic matter). Soil remediation techniques are based on physicochemical as well as biological methods or bioremediation. Bioremediation exploit the metabolic potential of live microorganisms (bacteria and fungi) for decontamination. Some of the most prominent biological methods for heavy metal remediation are sorption, precipitation, leaching and volatilization. However, more studies are needed on microbial diversity of sites contaminated with heavy metals to find the best-adapted strains with enhanced capabilities for bioremediation.