title: Characterization of a collection of plasmid-containing bacteria isolated from an on-farm biopurification system used for pesticide removal.
abstract: Biopurification systems (BPS) are complex soil-related and artificially-generated environments usually designed for the removal of toxic compounds from contaminated wastewaters. The present study has been conducted to isolate and characterize a collection of cultivable plasmid-carrying bacterial isolates recovered from a BPS established for the decontamination of wastewater generated in a farmyard. Out of 1400 isolates, a collection of 75 plasmid-containing bacteria was obtained, of which 35 representative isolates comprising in total at least 50 plasmids were chosen for further characterization. Bacterial hosts were taxonomically assigned by 16S ribosomal RNA gene sequencing and phenotypically characterized according to their ability to grow in presence of different antibiotics and heavy metals. The study demonstrated that a high proportion of the isolates was tolerant to antibiotics and/or heavy metals, highlighting the on-farm BPS enrichment in such genetic traits. Several plasmids conferring such resistances in the bacterial collection were detected to be either mobilizable or selftransmissible. Occurrence of broad host range plasmids of the incompatibility groups IncP, IncQ, IncN and IncW was examined with positive results only for the first group. Presence of the IS1071 insertion sequence, frequently associated with xenobiotics degradation genes, was detected in DNA obtained from 24 of these isolates, strongly suggesting the presence of yet-hidden catabolic activities in the collection of isolates. The results showed a remarkable diversity in the plasmid mobilome of cultivable bacteria in the BPS with the presence of abundant resistance markers of different types, thus providing a suitable environment to investigate the genetic structure of the mobile genetic pool in a model on-farm biofilter for wastewater decontamination in intensive agricultural production.
authors.affiliation: IBBM (Instituto de Biotecnología y Biología Molecular), CCT-CONICET-La Plata, Departamento de Ciencias Biológicas, Facultad de Ciencias Exactas, Universidad Nacional de La Plata, Calles 47 y 115, 1900 La Plata, Argentina.
authors.forename: María Carla
authors.initials: MC
authors.lastname: Martini
authors.affiliation: IBBM (Instituto de Biotecnología y Biología Molecular), CCT-CONICET-La Plata, Departamento de Ciencias Biológicas, Facultad de Ciencias Exactas, Universidad Nacional de La Plata, Calles 47 y 115, 1900 La Plata, Argentina.
authors.forename: Francisco Javier
authors.initials: FJ
authors.lastname: Albicoro
authors.affiliation: Julius Kühn-Institut - Federal Research Centre for Cultivated Plants (JKI), Messeweg 11/12, 38104 Braunschweig, Germany.
authors.forename: Eman
authors.initials: E
authors.lastname: Nour
authors.affiliation: Center for Biotechnology (CeBiTec), Institute for Genome Research and Systems Biology, Bielefeld University, D-33615 Bielefeld, Germany.
authors.forename: Andreas
authors.initials: A
authors.lastname: Schlüter
authors.affiliation: Research Centre, Plant Sciences Group, Wageningen University, 6708PB Wageningen, The Netherlands.
authors.forename: Jan Dirk
authors.initials: JD
authors.lastname: van Elsas
authors.affiliation: Division of Soil and Water Management, KU Leuven, Heverlee, Belgium.
authors.forename: Dirk
authors.initials: D
authors.lastname: Springael
authors.affiliation: Julius Kühn-Institut - Federal Research Centre for Cultivated Plants (JKI), Messeweg 11/12, 38104 Braunschweig, Germany.
authors.forename: Kornelia
authors.initials: K
authors.lastname: Smalla
authors.affiliation: IBBM (Instituto de Biotecnología y Biología Molecular), CCT-CONICET-La Plata, Departamento de Ciencias Biológicas, Facultad de Ciencias Exactas, Universidad Nacional de La Plata, Calles 47 y 115, 1900 La Plata, Argentina.
authors.forename: Mariano
authors.initials: M
authors.lastname: Pistorio
authors.affiliation: IBBM (Instituto de Biotecnología y Biología Molecular), CCT-CONICET-La Plata, Departamento de Ciencias Biológicas, Facultad de Ciencias Exactas, Universidad Nacional de La Plata, Calles 47 y 115, 1900 La Plata, Argentina.
authors.forename: Antonio
authors.initials: A
authors.lastname: Lagares
authors.affiliation: IBBM (Instituto de Biotecnología y Biología Molecular), CCT-CONICET-La Plata, Departamento de Ciencias Biológicas, Facultad de Ciencias Exactas, Universidad Nacional de La Plata, Calles 47 y 115, 1900 La Plata, Argentina. Electronic address: floppy@biol.unlp.edu.ar.
authors.forename: María Florencia
authors.initials: MF
authors.lastname: Del Papa
mesh_terms: D000383:Agriculture; D001673:Biodegradation, Environmental; D004269:DNA, Bacterial / Q000235:genetics; D020563:Gammaproteobacteria / Q000187:drug effects / Q000235:genetics / Q000302:isolation & purification*; D019216:Metals, Heavy / Q000494:pharmacology; D008826:Microbial Sensitivity Tests; D058889:Molecular Typing; D010573:Pesticide Residues / Q000302:isolation & purification; D010957:Plasmids / Q000235:genetics*; D012336:RNA, Ribosomal, 16S / Q000235:genetics; D012988:Soil Microbiology; D014874:Water Pollutants, Chemical / Q000302:isolation & purification; D018508:Water Purification
chemical_list: D004269:DNA, Bacterial; D019216:Metals, Heavy; D010573:Pesticide Residues; D012336:RNA, Ribosomal, 16S; D014874:Water Pollutants, Chemical
keywords: Biopurification system; Mobile genetic element; Pesticide; Plasmid