title: Heterotrophic Proteobacteria in the vicinity of diffuse hydrothermal venting.
abstract: Deep-sea hydrothermal vents are highly dynamic habitats characterized by steep temperature and chemical gradients. The oxidation of reduced compounds dissolved in the venting fluids fuels primary production providing the basis for extensive life. Until recently studies of microbial vent communities have focused primarily on chemolithoautotrophic organisms. In our study, we targeted the change of microbial community compositions along mixing gradients, focusing on distribution and capabilities of heterotrophic microorganisms. Samples were retrieved from different venting areas within the Menez Gwen hydrothermal field, taken along mixing gradients, including diffuse fluid discharge points, their immediate surroundings and the buoyant parts of hydrothermal plumes. High throughput 16S rRNA gene amplicon sequencing, fluorescence in situ hybridization, and targeted metagenome analysis were combined with geochemical analyses. Close to diffuse venting orifices dominated by chemolithoautotrophic Epsilonproteobacteria, in areas where environmental conditions still supported chemolithoautotrophic processes, we detected microbial communities enriched for versatile heterotrophic Alpha- and Gammaproteobacteria. The potential for alkane degradation could be shown for several genera and yet uncultured clades. We propose that hotspots of chemolithoautotrophic life support a 'belt' of heterotrophic bacteria significantly different from the dominating oligotrophic microbiota of the deep sea.
authors.affiliation: Max Planck Institute for Marine Microbiology, Celsiusstrasse 1, D-28359, Bremen, Germany.
authors.forename: Dimitri V
authors.initials: DV
authors.lastname: Meier
authors.affiliation: University of Bremen, MARUM - Center for Marine Environmental Sciences, Petrology of the Ocean Crust group, Leobener Str., D-28359, Bremen, Germany.
authors.forename: Wolfgang
authors.initials: W
authors.lastname: Bach
authors.affiliation: Harvard University, Department of Organismic & Evolutionary Biology, 16 Divinity Avenue, Cambridge, MA, 02138-2020, USA.
authors.forename: Peter R
authors.initials: PR
authors.lastname: Girguis
authors.affiliation: Max Planck Institute for Marine Microbiology, Celsiusstrasse 1, D-28359, Bremen, Germany.
authors.forename: Harald R
authors.initials: HR
authors.lastname: Gruber-Vodicka
authors.affiliation: University of Bremen, MARUM - Center for Marine Environmental Sciences, Petrology of the Ocean Crust group, Leobener Str., D-28359, Bremen, Germany.|University of Bergen, Department of Earth Science and Centre for Geobiology, Postboks 7803, N-5020, Bergen, Norway.
authors.forename: Eoghan P
authors.initials: EP
authors.lastname: Reeves
authors.affiliation: Max Planck Institute for Marine Microbiology, Celsiusstrasse 1, D-28359, Bremen, Germany.
authors.forename: Michael
authors.initials: M
authors.lastname: Richter
authors.affiliation: Harvard University, Department of Organismic & Evolutionary Biology, 16 Divinity Avenue, Cambridge, MA, 02138-2020, USA.
authors.forename: Charles
authors.initials: C
authors.lastname: Vidoudez
authors.affiliation: Max Planck Institute for Marine Microbiology, Celsiusstrasse 1, D-28359, Bremen, Germany.
authors.forename: Rudolf
authors.initials: R
authors.lastname: Amann
authors.affiliation: Max Planck Institute for Marine Microbiology, Celsiusstrasse 1, D-28359, Bremen, Germany.
authors.forename: Anke
authors.initials: A
authors.lastname: Meyerdierks
mesh_terms: D004269:DNA, Bacterial / Q000235:genetics; D017753:Ecosystem; D052836:Heterotrophic Processes; D060086:Hydrothermal Vents / Q000382:microbiology*; D017404:In Situ Hybridization, Fluorescence; D054892:Metagenome; D020560:Proteobacteria / Q000145:classification / Q000235:genetics / Q000302:isolation & purification* / Q000378:metabolism*; D012336:RNA, Ribosomal, 16S / Q000235:genetics
chemical_list: D004269:DNA, Bacterial; D012336:RNA, Ribosomal, 16S