摘要：This study evaluated the phytoextraction capacity of the fern
Pteris vittata grown on a natural arsenic-rich soil of volcanic-origin from the Viterbo area in central Italy. This calcareous soil is characterized by an average arsenic concentration of 750 mg kg
−1, of which 28% is bioavailable. By means of micro-energy dispersive X-ray fluorescence spectrometry (μ-XRF) we detected As in
P. vittata fronds after just 10 days of growth, while a high As concentrations in fronds (5,000 mg kg
−1), determined by Inductively coupled plasma-optical emission spectrometry (ICP-OES), was reached after 5.5 months. Sixteen arsenate-tolerant bacterial strains were isolated from the
P. vittata rhizosphere, a majority of which belong to the
Bacillus genus, and of this majority only two have been previously associated with As
. Six bacterial isolates were highly As-resistant (> 100 mM) two of which, homologous to
Paenarthrobacter ureafaciens and
Beijerinckia fluminensis, produced a high amount of IAA and siderophores and have never been isolated from
P. vittata roots. Furthermore, five isolates contained the arsenate reductase gene (
arsC). We conclude that
P. vittata can efficiently phytoextract As when grown on this natural As-rich soil and a consortium of bacteria, largely different from that usually found in As-polluted soils, has been found in
P. vittata rhizosphere.
