The potential role of willow-associated bacteria in the phytoextraction of metal contaminated soil. (Research)
Toxic metal pollutions are detrimental for the environment as well as for human health. Phytoremediation is an eco-friendly remediation method that uses plants and their associated microorganisms to deal with polluted soil and groundwater. Although phytoremediation is a very promising technology, it still faces some obstacles. During phytoremediation of toxic metals, their bioavailability often is too low to be extracted from the soil within an acceptable time-span or the increased concentrations inside the plant can cause phytotoxicity. These obstacles can be tackled by exploiting the characteristics of plant-associated bacteria. These may produce siderophores and/or organic acids, enhancing the bioavailability of metals and/or possess metal-resistance/sequestration systems, which might reduce phytotoxicity. Several of the bacteria are also plant-growth-promoting. By using 4 willow clones with different metal extraction capacities and sensitivity to metals, it will be investigated if these differences are related to the associated bacteria. Therefore, we will isolate, identify and characterize the associated communities genotypically as well as phenotypically, creating a new bacterial database. Further, a selection of the most promising bacteria, possessing the appropriate characteristics will be inoculated in the different willow clones under laboratory and field conditions with the purpose to obtain an improved phytoextraction for cadmium /zinc and a reduced sensitivity to these metals, creating possibilities for future research and commercial applications. This project is part of the CMK core competence field exploring the possibilities for using bacteria to improve phytoremediation of polluted sites.
Period of project
01 October 2010 - 30 September 2014