Endophytes from Phragmites australis: their role in phytodepuration

Wastewater treatment is an alarming question and phytodepuration represents an efficient and cost-effective solution. Phragmites australis is generally used for phytodepuration and it excellently removes arsenic, iron and nickel from polluted water. The purification potential of its bacterial endophytic community has never been explored though. G.I.D.A. S.p.a uses P. australis for phytoremediation in a pilot plant, at Calice purifier, which treats the effluent from the Membrane Bioreactor plant. Endophytic bacterial strains were isolated from different P. australis compartments sampled before the activation of the Calice purifier and four additional times during a 18-months period, to analyze the dynamics of the bacterial communities. The analysis of the composition of the cultivable and total microbiota was carried out revealing that the microbial communities underwent modifications after the purifier’s activation, highlighting differences in the endophytic bacterial communities induced by wastewater. Strains with particular ability of growing in the presence of high concentration of boron, selenium, iron, and sodium chloride were isolated, characterized, and their genome sequenced and analyzed. These strains might be utilized as inoculants to check whether they may increase the phytodepuration ability of P. australis.