title: The impact of long-term hydrocarbon exposure on the structure, activity, and biogeochemical functioning of microbial mats.
abstract: Photosynthetic microbial mats are metabolically structured systems driven by solar light. They are ubiquitous and can grow in hydrocarbon-polluted sites. Our aim is to determine the impact of chronic hydrocarbon contamination on the structure, activity, and functioning of a microbial mat. We compared it to an uncontaminated mat harboring similar geochemical characteristics. The mats were sampled in spring and fall for 2years. Seasonal variations were observed for the reference mat: sulfur cycle-related bacteria dominated spring samples, while Cyanobacteria dominated in autumn. The contaminated mat showed minor seasonal variation; a progressive increase of Cyanobacteria was noticed, indicating a perturbation of the classical seasonal behavior. Hydrocarbon content was the main factor explaining the differences in the microbial community structure; however, hydrocarbonoclastic bacteria were among rare or transient Operational Taxonomic Units (OTUs) in the contaminated mat. We suggest that in long-term contaminated systems, hydrocarbonoclastic bacteria cannot be considered a sentinel of contamination.
authors.affiliation: Equipe Environnement et Microbiologie, IPREM UMR CNRS 5254, Université de Pau et des Pays de l'Adour, IBEAS, BP 1155, 64013 Pau Cedex, France. Electronic address: johanne.aube@univ-pau.fr.
authors.forename: Johanne
authors.initials: J
authors.lastname: Aubé
authors.affiliation: Equipe Environnement et Microbiologie, IPREM UMR CNRS 5254, Université de Pau et des Pays de l'Adour, IBEAS, BP 1155, 64013 Pau Cedex, France; Plateforme Bioinformatique Genotoul, UR875, Biométrie et Intelligence Artificielle, INRA, 31326 Castanet-Tolosan, France. Electronic address: seninp@gmail.com.
authors.forename: Pavel
authors.initials: P
authors.lastname: Senin
authors.affiliation: UMR 9190 MARBEC IRD-Ifremer-CNRS, Université de Montpellier, Place Eugène Bataillon, Case 093, 34095 Montpellier Cedex 5, France. Electronic address: olivier.pringault@ird.fr.
authors.forename: Olivier
authors.initials: O
authors.lastname: Pringault
authors.affiliation: MIO, Institut Méditerranéen d'Océanologie, UMR 7294, F13288 Marseille, France. Electronic address: patricia.bonin@mio.osupytheas.fr.
authors.forename: Patricia
authors.initials: P
authors.lastname: Bonin
authors.affiliation: EPOC, UMR 5805, Université de Bordeaux, F33615 Pessac, France. Electronic address: b.deflandre@epoc.u-bordeaux1.fr.
authors.forename: Bruno
authors.initials: B
authors.lastname: Deflandre
authors.affiliation: GeT-PlaGe, Genotoul, INRA Auzeville, F31326 Castanet-Tolosan, France. Electronic address: olivier.bouchez@toulouse.inra.fr.
authors.forename: Olivier
authors.initials: O
authors.lastname: Bouchez
authors.affiliation: Université de Pau et des Pays de l'Adour, Laboratoire de Mathématiques et de leurs Applications de Pau, UMR CNRS 5142, FED 4155 MIRA, Campus Montaury, 64600 Anglet, France. Electronic address: noelle.bur@univ-pau.fr.
authors.forename: Noëlle
authors.initials: N
authors.lastname: Bru
authors.affiliation: Université de Pau et des Pays de l'Adour, Laboratoire de Mathématiques et de leurs Applications de Pau, UMR CNRS 5142, FED 4155 MIRA, Campus Montaury, 64600 Anglet, France. Electronic address: edurne.biritxinaga-etchart@univ-pau.fr.
authors.forename: Edurne
authors.initials: E
authors.lastname: Biritxinaga-Etchart
authors.affiliation: Plateforme Bioinformatique Genotoul, UR875, Biométrie et Intelligence Artificielle, INRA, 31326 Castanet-Tolosan, France. Electronic address: christophe.Klopp@toulouse.inra.fr.
authors.forename: Christophe
authors.initials: C
authors.lastname: Klopp
authors.affiliation: Equipe Environnement et Microbiologie, IPREM UMR CNRS 5254, Université de Pau et des Pays de l'Adour, IBEAS, BP 1155, 64013 Pau Cedex, France. Electronic address: remy.guyoneaud@univ-pau.fr.
authors.forename: Rémy
authors.initials: R
authors.lastname: Guyoneaud
authors.affiliation: Equipe Environnement et Microbiologie, IPREM UMR CNRS 5254, Université de Pau et des Pays de l'Adour, IBEAS, BP 1155, 64013 Pau Cedex, France. Electronic address: marisol.goni@univ-pau.fr.
authors.forename: Marisol
authors.initials: M
authors.lastname: Goñi-Urriza
mesh_terms: D001419:Bacteria / Q000378:metabolism; D000458:Cyanobacteria / Q000378:metabolism; D005602:France; D006838:Hydrocarbons / Q000032:analysis / Q000633:toxicity*; D059013:Microbial Consortia / Q000187:drug effects / Q000235:genetics / Q000502:physiology*; D010788:Photosynthesis; D012336:RNA, Ribosomal, 16S; D012621:Seasons; D013455:Sulfur / Q000378:metabolism; D014874:Water Pollutants, Chemical / Q000633:toxicity
chemical_list: D006838:Hydrocarbons; D012336:RNA, Ribosomal, 16S; D014874:Water Pollutants, Chemical; D013455:Sulfur
keywords: Biogeochemical functioning; Diversity; Hydrocarbonoclastic bacteria; Microbial mats