title: Biogeochemical insights into microbe-mineral-fluid interactions in hydrothermal chimneys using enrichment culture.
abstract: Active hydrothermal chimneys host diverse microbial communities exhibiting various metabolisms including those involved in various biogeochemical cycles. To investigate microbe-mineral-fluid interactions in hydrothermal chimney and the driver of microbial diversity, a cultural approach using a gas-lift bioreactor was chosen. An enrichment culture was performed using crushed active chimney sample as inoculum and diluted hydrothermal fluid from the same vent as culture medium. Daily sampling provided time-series access to active microbial diversity and medium composition. Active archaeal and bacterial communities consisted mainly of sulfur, sulfate and iron reducers and hydrogen oxidizers with the detection of Thermococcus, Archaeoglobus, Geoglobus, Sulfurimonas and Thermotoga sequences. The simultaneous presence of active Geoglobus sp. and Archaeoglobus sp. argues against competition for available carbon sources and electron donors between sulfate and iron reducers at high temperature. This approach allowed the cultivation of microbial populations that were under-represented in the initial environmental sample. The microbial communities are heterogeneously distributed within the gas-lift bioreactor; it is unlikely that bulk mineralogy or fluid chemistry is the drivers of microbial community structure. Instead, we propose that micro-environmental niche characteristics, created by the interaction between the mineral grains and the fluid chemistry, are the main drivers of microbial diversity in natural systems.
authors.affiliation: Laboratoire de Microbiologie des Environnements Extrêmes, Université de Bretagne Occidentale, UEB, IUEM, UMR 6197, Place Nicolas Copernic, 29280, Plouzané, France, nolwenn.callac@gmail.com.
authors.forename: Nolwenn
authors.initials: N
authors.lastname: Callac
authors.forename: Olivier
authors.initials: O
authors.lastname: Rouxel
authors.forename: Françoise
authors.initials: F
authors.lastname: Lesongeur
authors.forename: Céline
authors.initials: C
authors.lastname: Liorzou
authors.forename: Claire
authors.initials: C
authors.lastname: Bollinger
authors.forename: Patricia
authors.initials: P
authors.lastname: Pignet
authors.forename: Sandrine
authors.initials: S
authors.lastname: Chéron
authors.forename: Yves
authors.initials: Y
authors.lastname: Fouquet
authors.forename: Céline
authors.initials: C
authors.lastname: Rommevaux-Jestin
authors.forename: Anne
authors.initials: A
authors.lastname: Godfroy
mesh_terms: D001105:Archaea / Q000302:isolation & purification / Q000378:metabolism; D001419:Bacteria / Q000302:isolation & purification / Q000378:metabolism; D019149:Bioreactors / Q000382:microbiology*; D060086:Hydrothermal Vents / Q000737:chemistry / Q000382:microbiology*; D064307:Microbiota; D008903:Minerals / Q000032:analysis / Q000378:metabolism*; D010084:Oxidation-Reduction; D013455:Sulfur / Q000378:metabolism
chemical_list: D008903:Minerals; D013455:Sulfur