Remediación biológica de mercurio: Recientes avances

Abstract

Mercury (Hg) is a highly toxic heavy metal that threatens human health and environment. It is found naturally as inorganic and organic forms and all are toxic, especially the latter, due to its high lipid solubility, which facilitates their biomagnification in the food chain. Due to the high risks that represent the Hg-contaminated environments, there is a need to efficiently treat them. Among environmental restoration strategies, the biological remediation is a promising technology, which comprises the bio-, phyco-, phyto- and rhizoremediation. Thus, the purpose of this review was to compilate the main aspects concerning to biological remediation of Hg, emphasizing the most recent developments, in order to contribute to the understanding of the mechanisms involved in it and the aspects that still need to be investigated. Thereby, in this review we describe the different mechanisms implicated and the capacity for Hg and methylmercury removal by bacteria, fungi, algae, plants and rhizospheric microorganisms. In addition, it describes the results using transgenic plants, which have been obtained to improve the removal process of this metal. For decades, numerous investigation involving bacterial bioremediation and phytoremediation of Hg have been developed. However, the use of fungi and algae for this purpose are less explored areas. More recently, new areas into the Hg-biological remediation are being studied, such as the rhizoremediation and the use of transgenic plants, which need to be further studied in order to elucidate its biotechnological potential. The application of these systems to treat industrial effluents and/or environments contaminated with Hg is also discussed.