PRJNA225620
Mesocosm mine tailing cores Targeted Locus (Loci)
The objective of this study was to analyze the temporal dynamics of the microbial communities colonizing the rhizosphere of plants growing in compost-amended mine tailings with the goal of linking community structure to ecosystem function. Metalliferous mine tailings, which usually have high acid-generating potentials, are often subject to phytoremediation to prevent the dispersion (by eolian and hydraulic action) of these metal-bearing particles. Assisted phytostabilization is a type of phytoremediation technology in which the mine tailings are amended with compost (as a source of carbon and nutrients, and pH buffer) and then are seeded with a native plant specie that has been specifically selected based on its capacity to grow on the tailings without accumulating elevated levels of toxic metals in the shoot tissues. Therefore, the metal contaminants are immobilized in the soil to minimize the health and environmental risks associated with the dispersion of exposed mine tailings. A major knowledge gap in the understanding of phytostabilization as a viable alternative for the remediation of mine tailing piles is the ecology of the microorganisms that grow in the root-zone of the plants. Little is known of how these microbial communities respond to plant growth and compost amendment, how they may influence the stabilization of the metal contaminants, how they may affect or enhance plant colonization of the tailings, and how their structure may reflect the state of the phytoremediation treatment. To try to answer some of these questions, we conducted a yearlong greenhouse experiment with 3 treatments (in triplicate): (1) tailings only control, (2) tailings amended with 15% compost control, (3) tailings amended with 15% compost and seeded with a shrub (quail-bush; Atriplex lentiformis). During that year, core samples were collected every 3 months to extract metagenomic DNA and analyze the structure of the microbial communities (i.e. phylogenetic and functional structure).