title: Magnetotactic bacteria in microcosms originating from the French Mediterranean Coast subjected to oil industry activities.
abstract: Magnetotactic bacteria (MTB) mineralize nanosized magnetite or greigite crystals within cells and thus play an important role in the biogeochemical process. Despite decades of research, knowledge of MTB distribution and ecology, notably in areas subjected to oil industry activities, is still limited. In the present study, we investigated the presence of MTB in the Gulf of Fos, French Mediterranean coast, which is subjected to intensive oil industry activities. Microcosms containing sediments/water (1:2, v/v) from several sampling sites were monitored over several weeks. The presence of MTB was revealed in five of eight sites. Diverse and numerous MTB were revealed particularly from one site (named CAR), whilst temporal variations of a homogenous magnetotactic cocci population was shown within the LAV site microcosm over a 4-month period. Phylogenetic analysis revealed that they belonged to Alphaproteobacteria, and a novel genus from the LAV site was evidenced. Among the physicochemical parameters measured, a correlation was shown between the variation of MTB abundance in microcosms and the redox state of sulphur compounds.
authors.affiliation: IRD, UMR_D 180, Université Aix Marseille, ESIL case 925, 163 Avenue de Luminy, 13288, Marseille Cedex 9, France.
authors.forename: Anne
authors.initials: A
authors.lastname: Postec
authors.forename: Nicolas
authors.initials: N
authors.lastname: Tapia
authors.forename: Alain
authors.initials: A
authors.lastname: Bernadac
authors.forename: Manon
authors.initials: M
authors.lastname: Joseph
authors.forename: Sylvain
authors.initials: S
authors.lastname: Davidson
authors.forename: Long-Fei
authors.initials: LF
authors.lastname: Wu
authors.forename: Bernard
authors.initials: B
authors.lastname: Ollivier
authors.forename: Nathalie
authors.initials: N
authors.lastname: Pradel
mesh_terms: D020561:Alphaproteobacteria / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism*; D059001:Aquatic Organisms / Q000378:metabolism; D004269:DNA, Bacterial / Q000032:analysis / Q000737:chemistry / Q000235:genetics; D052203:Ferrosoferric Oxide / Q000378:metabolism*; D005602:France; D014644:Genetic Variation; D019015:Geologic Sediments / Q000382:microbiology; D007219:Industrial Oils; D007501:Iron / Q000378:metabolism*; D055944:Magnetosomes / Q000502:physiology; D019083:Mediterranean Region; D008969:Molecular Sequence Data; D061329:Oil and Gas Fields / Q000382:microbiology; D010084:Oxidation-Reduction; D010802:Phylogeny; D012336:RNA, Ribosomal, 16S / Q000235:genetics; D017422:Sequence Analysis, DNA; D013440:Sulfides / Q000378:metabolism*; D013457:Sulfur Compounds
chemical_list: D004269:DNA, Bacterial; D012336:RNA, Ribosomal, 16S; D013440:Sulfides; D013457:Sulfur Compounds; C111959:greigite; D007501:Iron; D052203:Ferrosoferric Oxide