Aim of this project was to sequence plant-associated bacteria genomes showing plant-growth promotion properties and elevated heavy-metal resistance phenotypes to 1) devise better molecular screen for such strains 2) use these for bioaugmentation of marginal lands contaminated by heavy-metals.. Phyto2Energy

Post-industrial sites are responsible for 60% of soil pollution in the EU and 37% of these sites are contaminated with heavy- metals. Phytoremediation is often envisaged to reclaim these sites but that process is slow. Inoculation of plant-growth promoting (PGP) microorganisms could however considerably improve it, providing chosen strains can withstand elevated concentrations of toxic metals, either in the soil or within accumulator plant tissue. Also, PGP microorganisms can decrease heavy-metal toxicity in plants allowing non metallophytes plants to grow efficiently on marginal lands. Our objectives in that study were 1) to identify candidate PGP for improved phytoremediation 2) to decipher the genetic basis of such complex traits in order to advance knowledge on plant-host interactions and heavy-metal adaptation. A collection of 134 isolates from rhizospheric soil or surface sterilized plant tissues of Miscanthus x giganteus and Sida hermaphrodita, growing on a soil contaminated by Zn, Pb and Cd (Bytom, PL) were tested for various PGP properties and their ability to grow in presence of toxic heavy metals. Isolates were identified by 16S rRNA sequencing: Bacillus (50%) and Pseudomonas (18%) were the most prevalent genera. Ten new Pseudomonas isolates sequenced using Illumina MiSeq. Draft assembly with SPADES and complete genome assembly of strain E41 using PacBio data. Comparative genomic with all available Pseudomonas complete genomes identify putative genes involved in plant-growth promotion, endophytic lifestyle and heavy-metal resistance.