The industrial and agricultural development caused a metallic element accumulation in the soils. In these ecosystems, the living fraction significantly operates in the changes of contaminants retention. Among the decontamination techniques, the phytoremediation appears as a tool of choice. If one of major disadvantages of this technique is the long-term remediation process, the addition of microorganisms with the plants could enhance the uptakes and decrease the time to remediate. This work focused on the possibility to develop processes for siderophore-producing bacteria-assisted phytoremediation, siderophores being molecules with a high affinity for iron and also able to chelate other metals. In this context, a system with an increasing complexity until a complete model including the soil constituents, the bacteria, the contaminant metals and the plants, has been studied to understand the processes involved in these different interactions. The understanding of the interactions between the soil minerals, clays and iron oxydydroxides, and a siderophore-producing bacteria, Pseudomonas aeruginosa, have been first performed with, in particular, a molecular biology approach. These results have highlighted the major role of the one of siderophores, the pyoverdine, and also the biofilm in the mineral dissolution by this bacteria. Fluorimetry and metal quantification assays showed that the pyoverdine was able to chelate the contaminant metals adsorbed on the clays or present in the crystal structure of the iron oxyhydroxides. Lastly, the global system has demonstrated that if the pyoverdine or the siderophore-producing bacteria do not enhance the cadmium and nickel uptake by plants, promising results were obtained for copper. Moreover, siderophore-producing bacteria turn out to be interesting asset for the phytostabilization.
