title: Chemical and microbiological characterization of an aged PCB-contaminated soil.
abstract: This study was aimed at complex characterization of three soil samples (bulk soil, topsoil and rhizosphere soil) from a site historically contaminated with polychlorinated biphenyls (PCB). The bulk soil was the most highly contaminated, with a PCB concentration of 705.95 mg kg(-1), while the rhizosphere soil was the least contaminated (169.36 mg kg(-1)). PCB degradation intermediates, namely chlorobenzoic acids (CBAs), were detected in all the soil samples, suggesting the occurrence of microbial transformation processes over time. The higher content of organic carbon in the topsoil and rhizosphere soil than in the bulk soil could be linked to the reduced bioaccessibility (bioavailability) of these chlorinated pollutants. However, different proportions of the PCB congener contents and different bioaccessibility of the PCB homologues indicate microbial biotransformation of the compounds. The higher content of organic carbon probably also promoted the growth of microorganisms, as revealed by phospholipid fatty acid (PFLA) quantification. Tag-encoded pyrosequencing analysis showed that the bacterial community structure was significantly similar among the three soils and was predominated by Proteobacteria (44-48%) in all cases. Moreover, analysis at lower taxonomic levels pointed to the presence of genera (Sphingomonas, Bulkholderia, Arthrobacter, Bacillus) including members with reported PCB removal abilities. The fungal community was mostly represented by Basidiomycota and Ascomycota, which accounted for >80% of all the sequences detected in the three soils. Fungal taxa with biodegradation potential (Paxillus, Cryptococcus, Phoma, Mortierella) were also found. These results highlight the potential of the indigenous consortia present at the site as a starting point for PCB bioremediation processes.
authors.affiliation: Institute of Microbiology, Academy of Sciences of the Czech Republic v.v.i., Vídeňská 1083, CZ-142 20 Prague 4, Czech Republic; Department for Innovation in Biological, Agro-food and Forest Systems (DIBAF), University of Tuscia, Via S. Camillo De Lellis, 01100 Viterbo, Italy; Institute for Environmental Studies, Faculty of Science, Charles University in Prague, Benátská 2, CZ-128 01 Prague 2, Czech Republic.
authors.forename: T
authors.initials: T
authors.lastname: Stella
authors.affiliation: Institute of Microbiology, Academy of Sciences of the Czech Republic v.v.i., Vídeňská 1083, CZ-142 20 Prague 4, Czech Republic.
authors.forename: S
authors.initials: S
authors.lastname: Covino
authors.affiliation: Institute of Microbiology, Academy of Sciences of the Czech Republic v.v.i., Vídeňská 1083, CZ-142 20 Prague 4, Czech Republic.
authors.forename: E
authors.initials: E
authors.lastname: Burianová
authors.affiliation: Institute of Microbiology, Academy of Sciences of the Czech Republic v.v.i., Vídeňská 1083, CZ-142 20 Prague 4, Czech Republic.
authors.forename: A
authors.initials: A
authors.lastname: Filipová
authors.affiliation: Institute of Microbiology, Academy of Sciences of the Czech Republic v.v.i., Vídeňská 1083, CZ-142 20 Prague 4, Czech Republic.
authors.forename: Z
authors.initials: Z
authors.lastname: Křesinová
authors.affiliation: Institute of Microbiology, Academy of Sciences of the Czech Republic v.v.i., Vídeňská 1083, CZ-142 20 Prague 4, Czech Republic.
authors.forename: J
authors.initials: J
authors.lastname: Voříšková
authors.affiliation: Institute of Microbiology, Academy of Sciences of the Czech Republic v.v.i., Vídeňská 1083, CZ-142 20 Prague 4, Czech Republic.
authors.forename: T
authors.initials: T
authors.lastname: Větrovský
authors.affiliation: Institute of Microbiology, Academy of Sciences of the Czech Republic v.v.i., Vídeňská 1083, CZ-142 20 Prague 4, Czech Republic.
authors.forename: P
authors.initials: P
authors.lastname: Baldrian
authors.affiliation: Institute of Microbiology, Academy of Sciences of the Czech Republic v.v.i., Vídeňská 1083, CZ-142 20 Prague 4, Czech Republic; Institute for Environmental Studies, Faculty of Science, Charles University in Prague, Benátská 2, CZ-128 01 Prague 2, Czech Republic. Electronic address: cajthaml@biomed.cas.cz.
authors.forename: T
authors.initials: T
authors.lastname: Cajthaml
mesh_terms: D001173:Arthrobacter; D001673:Biodegradation, Environmental; D004784:Environmental Monitoring; D011078:Polychlorinated Biphenyls / Q000032:analysis*; D058441:Rhizosphere; D012987:Soil / Q000737:chemistry; D012988:Soil Microbiology; D012989:Soil Pollutants / Q000032:analysis*
chemical_list: D012987:Soil; D012989:Soil Pollutants; D011078:Polychlorinated Biphenyls
keywords: Bioaccessibility; Bioavailability; Bioremediation; Chlorobenzoic acids; Microbial communities; Polychlorinated biphenyls