Metagenomics: Potential for bioremediation of soil contaminated with heavy metals

Heavy metal pollution has caused serious environmental crises worldwide and has drawn a great deal of attention from ecologists. Owing to their high toxicity, non-biodegradability, and long residence times, heavy metals have a great impact on both the ecological systems and human health. The United States Environmental Protection Agency recognizes Pb, Cu, Zn, As, Cr, Cd, and Ni as priority control heavy metal pollutants. Bioremediation, an approach to clean up the contamination in the environment, can be carried out using microorganisms, plants, and animals. In this review, the development and studies of microorganisms-based bioremediation are summarized. In addition, the mechanism of the microbial resistance system and its putative remediation ability to remove toxic metals are discussed from the viewpoints of metagenomics and metatranscriptomics.