title: Phytomediated biostimulation of the autochthonous bacterial community for the acceleration of the depletion of polycyclic aromatic hydrocarbons in contaminated sediments.
abstract: Polycyclic aromatic hydrocarbons (PAHs) are a large group of organic contaminants causing hazards to organisms including humans. The objective of the study was to validate the vegetation of dredged sediments with Phragmites australis as an exploitable biostimulation approach to accelerate the depletion of PAHs in nitrogen spiked sediments. Vegetation with Phragmites australis resulted in being an efficient biostimulation approach for the depletion of an aged PAHs contamination (229.67 ± 15.56 μg PAHs/g dry weight of sediment) in dredged sediments. Phragmites australis accelerated the oxidation of the PAHs by rhizodegradation. The phytobased approach resulted in 58.47% of PAHs depletion. The effects of the treatment have been analyzed in terms of both contaminant depletion and changes in relative abundance of the metabolically active Gram positive and Gram negative PAHs degraders. The metabolically active degraders were quantified both in the sediments and in the root endospheric microbial community. Quantitative real-time PCR reactions have been performed on the retrotranscribed transcripts encoding the Gram positive and Gram negative large α subunit (RHDα) of the aromatic ring hydroxylating dioxygenases. The Gram positive degraders resulted in being selectively favored by vegetation with Phragmites australis and mandatory for the depletion of the six ring condensed indeno[1,2,3-cd]pyrene and benzo[g,h,i]perylene.
authors.affiliation: Department of Biology, University of Pisa, 56126 Pisa, Italy.
authors.forename: Simona
authors.identifier: 0000-0002-8425-4491
authors.initials: S
authors.lastname: Di Gregorio
authors.affiliation: Teseco SpA, Via Carlo Ludovico Ragghianti 12, 56121 Pisa, Italy.
authors.forename: Alessandro
authors.initials: A
authors.lastname: Gentini
authors.affiliation: Department of Biology, University of Pisa, 56126 Pisa, Italy.
authors.forename: Giovanna
authors.identifier: 0000-0002-9592-8666
authors.initials: G
authors.lastname: Siracusa
authors.affiliation: STA srl, Via della Gherardesca 2, Ospedaletto, 56121 Pisa, Italy.
authors.forename: Simone
authors.initials: S
authors.lastname: Becarelli
authors.affiliation: Institute of Applied Research (Affiliated with University of Haifa), The Galilee Society, P.O. Box 437, 20200 Shefa-Amr, Israel ; Tel Hai College, 12208 Upper Galilee, Israel.
authors.forename: Hassan
authors.initials: H
authors.lastname: Azaizeh
authors.affiliation: Department of Biology, University of Pisa, 56126 Pisa, Italy.
authors.forename: Roberto
authors.identifier: 0000-0001-9542-0806
authors.initials: R
authors.lastname: Lorenzi
mesh_terms: D004784:Environmental Monitoring; D019015:Geologic Sediments / Q000382:microbiology; D006090:Gram-Negative Bacteria / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism*; D006094:Gram-Positive Bacteria / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism*; D006801:Humans; D011084:Polycyclic Aromatic Hydrocarbons / Q000737:chemistry* / Q000378:metabolism; D012336:RNA, Ribosomal, 16S / Q000235:genetics; D014874:Water Pollutants, Chemical / Q000737:chemistry / Q000378:metabolism
chemical_list: D011084:Polycyclic Aromatic Hydrocarbons; D012336:RNA, Ribosomal, 16S; D014874:Water Pollutants, Chemical