Rhizosphere Management for Phytoremediation of Copper Mine Tailings

Copper (Cu) is essential for plant growth, but due to increased pollution in the last decades, Cu contamination has become a serious environmental concern. Different techniques have been carried out for the remediation of the negative effects of Cu excess, being the phytoremediation a sustainable strategy. In this scenario, the arbuscular mycorrhizal fungi (AMF) emerge as a powerful tool for increasing the plant cover in Cu mine tailings. Moreover, the use of organic amendments has proven to be another interesting tool which in combinations with AMF increases nutrient availability and water absorption. Recent studies have been performed to alleviate abiotic stress conditions using AMF and other plant growth promoting rhizosphere microorganisms, as free-living fungi and bacteria. Although studies of these microorganisms in conjunction with AMF in phytoremediation are scarce, the characteristics and mechanisms of action suggest a great potential for phytoremediation employing the management of microbial communities and the conditioning by amendments. The combined use of the above resources emerges as a new approach to develop improved phytoremediation techniques based on the rhizosphere management, which is summarized in this review. Here, we also describe the new advances in the directed use of soil microorganisms and amendments, as well as discuss the advantages for phytoremediation processes, mainly focused on the stabilization of mine tailing, which has become one of the most serious environmental problems in places where the mining activities are of magnitude.