The Potential of PGPR Activity in Phytoremediation: Case Studies of Contaminated Soils

Phytoremediation is an appropriate and sustainable technology used to clean up pollutants from soils and waters through plant species. They are naturally capable of absorbing metals and degrading organic molecules, but often, the presence of contaminants causes suffering to plants driving limited growth. In these situations, thanks to the production of specific root exudates, the plants can engage the most suitable bacteria capable of supporting their growth according to the particular environmental stress. These rhizobacteria (PGPR) promote the growth and development of plants with numerous beneficial effects, even more evident when plants are grown in critical environmental conditions, such as toxic contaminants. A better and deeper understanding of the interactions between plants-microorganisms directly in the matrix of interest, especially in the presence of persistent contamination, could provide new opportunities for phytoremediation. PGPR can alleviate the phytotoxicity of metals in the soil by altering their bioavailability and increasing the translocation of metals within the plant or excluding their uptake. Lead (Pb), mercury (Hg) and arsenic (As) are among the most toxic metals (metalloids). We report some phytoextraction results with three different soils contaminated by i) As and Hg , (ii) As and iii) Pb.