Phytoextraction process optimization : characterization of the soil bacteria flora associated to the hyperaccumulator Arabidopsis halleri

Abstract : Phytotechnologies are microbial-assisted techniques that use living plants for the treatment of contaminated sites. Among these, phytoextraction based on hyperaccumulator plants such as Arabidopsis halleri, may be an option to remove trace elements in soil. One method to optimize Arabidopsis halleri's phytoextraction is the inoculation of plant roots by plant growth promoting bacteria (PGPB). In this study, we analyzed the total bacterial diversity in a Zn and Cd contaminated industrial soil (Auby, France) with restriction fragment length polymorphism (RFLP). Preliminary results showed a large bacterial diversity in Auby's soil. Cultivable bacteria were isolated and characterized for their PGPB traits (ACC deaminase activity, siderophores and Indol-Acetic-Acid (IAA) productions). Bacteria that will answer positively to the three PGPB tests will be preferentially selected, and inoculated to Arabidopsis halleri roots. Bacteria effects on plant biomass and/or accumulating yield will be presented.