GEOSCAN, résultats de la recherche


TitreMacroscopic biofilms in fracture-dominated sediment that anaerobically oxidize methane
AuteurBriggs, B R; Pohlman, J W; Torres, M; Riedel, M; Brodie, E L; Colwell, F S
SourceApplied and Environmental Microbiology vol. 77, no. 19, 2011 p. 6780-6787, (Accès ouvert)
Séries alt.Secteur des sciences de la Terre, Contribution externe 20110050
ÉditeurAmerican Society for Microbiology
Documentpublication en série
Mediapapier; en ligne; numérique
ProvinceRégion extracotière de l'ouest
Lat/Long OENS-127.0000 -126.8333 48.7083 48.6500
Lat/Long OENS-125.0667 -125.0667 44.5833 44.5667
Lat/Long OENS 81.8333 86.0000 19.1667 15.8000
Sujetsméthane; hydrate; phylogénie; etudes isotopiques; échantillons carrotés; carottes; carottes de sédiment marin; études des isotopes stables; sulfate; fractures; établissement de modèles; géochimie; géologie marine
Illustrationsphotographs; models
ProgrammeCaractérisation des Hydrates de gaz, Hydrates de gaz
Diffusé2011 08 05
Résumé(disponible en anglais seulement)
Methane release from seafloor sediments is moderated, in part, by the anaerobic oxidation of methane (AOM) performed by consortia of archaea and bacteria. These consortia occur as isolated cells and aggregates within the sulfate methane transition (SMT) of diffusion and seep-dominant environments. Here we report on a new SMT setting, where the AOM consortium occurs as macroscopic pink to orange biofilms within subseafloor fractures. Biofilm samples recovered from the Indian and northeast Pacific Oceans had a cellular abundance of 107 to 108 cells cm-3. This cell density is 2-3 orders of magnitude greater than that in the surrounding sediments. Sequencing of bacterial 16S rRNA genes indicated that the bacterial component is dominated by Deltaproteobacteria, candidate division WS3, and Chloroflexi, representing 46%, 15% and 10% of clones, respectively. In addition, major archaeal taxa found in the biofilm were related to ANME-1, Thermoplasmatales, and Desulfurococcales, representing 73%, 11%, and 10% of archaeal clones, respectively. All major taxa were similar to sequences previously reported from cold seep environments. PhyloChip microarray analysis detected all bacterial phyla identified by the clone library plus an additional 44 phyla. However, sequencing detected more archaea than the PhyloChip within the phyla of Methanosarcinales and Desulfurococcales. The stable carbon isotope composition of biofilm from the SMT (-35 to -43¿) suggests the production of the biofilm is associated with AOM. These biofilms are a novel, but apparently widespread, aggregation of cells represented by the ANME-1 clade that occur in methane-rich marine sediments.