title: Microbial diversity in deep-sea sediments from the Menez Gwen hydrothermal vent system of the Mid-Atlantic Ridge.
abstract: Deep-sea hydrothermal sediments are known to support remarkably diverse microbial consortia. Cultureindependent sequence-based technologies have extensively been used to disclose the associated microbial diversity as most of the microorganisms inhabiting these ecosystems remain uncultured. Here we provide the first description of the microbial community diversity found on sediments from Menez Gwen vent system. We compared hydrothermally influenced sediments, retrieved from an active vent chimney at 812 m depth, with non-hydrothermally influenced sediments, from a 1400 m depth bathyal plain. Considering the enriched methane and sulfur composition of Menez Gwen vent fluids, and the sediment physicochemical properties in each sampled area, we hypothesized that the site-associated microbes would be different. To address this question, taxonomic profiles of bacterial, archaeal and micro-eukaryotic representatives were studied by rRNA gene tag pyrosequencing. Communities were shown to be significantly different and segregated by sediment geographical area. Specific mesophilic, thermophilic and hyperthermophilic archaeal (e.g., Archaeoglobus, ANME-1) and bacterial (e.g., Caldithrix, Thermodesulfobacteria) taxa were highly abundant near the vent chimney. In contrast, bathyal-associated members affiliated to more ubiquitous phylogroups from deep-ocean sediments (e.g., Thaumarchaeota MGI, Gamma- and Alphaproteobacteria). This study provides a broader picture of the biological diversity and microbial biogeography, and represents a preliminary approach to the microbial ecology associated with the deep-sea sediments from the Menez Gwen hydrothermal vent field.
authors.affiliation: IMAR Centre and MARE- Marine and Environmental Sciences Centre, Department of Oceanography and Fisheries, University of the Azores, Rua Prof. Dr. Frederico Machado, 9901-862 Horta, Portugal. Electronic address: mcerqueira@uac.pt.
authors.forename: Teresa
authors.initials: T
authors.lastname: Cerqueira
authors.affiliation: Next Generation Sequencing Unit - BIOCANT, Parque Tecnológico de Cantanhede, Núcleo 04, Lote 8, 3060-197 Cantanhede, Portugal.
authors.forename: Diogo
authors.initials: D
authors.lastname: Pinho
authors.affiliation: Next Generation Sequencing Unit - BIOCANT, Parque Tecnológico de Cantanhede, Núcleo 04, Lote 8, 3060-197 Cantanhede, Portugal.
authors.forename: Conceição
authors.initials: C
authors.lastname: Egas
authors.affiliation: Next Generation Sequencing Unit - BIOCANT, Parque Tecnológico de Cantanhede, Núcleo 04, Lote 8, 3060-197 Cantanhede, Portugal.
authors.forename: Hugo
authors.initials: H
authors.lastname: Froufe
authors.affiliation: Department of Chemistry, Faculty of Science and Technology, University of Tromsø, N-9037 Tromsø, Norway.
authors.forename: Bjørn
authors.initials: B
authors.lastname: Altermark
authors.affiliation: GeoBioTec - Geobiosciences, Geotechnologies and Geoengineering Research Center, University of Aveiro, Campus de Santiago, 3810-193 Aveiro, Portugal.
authors.forename: Carla
authors.initials: C
authors.lastname: Candeias
authors.affiliation: IMAR Centre and MARE- Marine and Environmental Sciences Centre, Department of Oceanography and Fisheries, University of the Azores, Rua Prof. Dr. Frederico Machado, 9901-862 Horta, Portugal.
authors.forename: Ricardo S
authors.initials: RS
authors.lastname: Santos
authors.affiliation: IMAR Centre and MARE- Marine and Environmental Sciences Centre, Department of Oceanography and Fisheries, University of the Azores, Rua Prof. Dr. Frederico Machado, 9901-862 Horta, Portugal.
authors.forename: Raul
authors.initials: R
authors.lastname: Bettencourt
mesh_terms: D001105:Archaea / Q000145:classification / Q000235:genetics*; D001267:Atlantic Ocean; D001419:Bacteria / Q000145:classification / Q000235:genetics*; D004247:DNA / Q000145:classification / Q000235:genetics*; D056890:Eukaryota / Q000145:classification / Q000235:genetics*; D019015:Geologic Sediments / Q000382:microbiology*; D060086:Hydrothermal Vents / Q000382:microbiology*; D012313:RNA / Q000235:genetics; D012335:RNA, Ribosomal / Q000235:genetics
chemical_list: D012335:RNA, Ribosomal; D012313:RNA; D004247:DNA
keywords: 16S rRNA gene; 454 pyrosequencing; Chemosynthetic environment; Deep-sea sediments; Microbial ecology