Implication of plants and microbial metalloproteins in the bioremediation of polluted waters: A review

Traditional approaches to municipal water monitoring barely includes procedures for toxic heavy metals testing. However, the presence of such contaminants in water sources is expected in South African surface and ground waters as a result of dispersion of effluents from acid mine drainage sites. Cheap and eco-friendly methods using microorganisms and plants are discussed in this review. Metal uptake mechanisms involving special proteins namely metalloproteins or metal-binding proteins and peptides, are elaborated and supported with some examples. The potential of phytochelatins and metallothioneins as metal chelating ligands in plants and microorganisms are reviewed and suggestion made to engineer these peptides in microbial sorbents for improved metal uptake. This review covers a number of approaches in the bioremediation of metal polluted effluents and systematically explains the mechanisms involved in the bio-uptake of metals, while highlighting the contribution of metal-binding proteins.