Identification of enriched hyperthermophilic microbial communities from a deep-sea hydrothermal vent chimney under electrolithoautotrophic culture conditions
|Author(s)||Pillot Guillaume1, Amin Ali Oulfat1, Davidson Sylvain1, Shintu Laetitia3, Godfroy Anne2, Combet-Blanc Yannick1, Bonin Patricia1, Liebgott Pierre-Pol1|
|Affiliation(s)||1 : Aix Marseille Université, Université de Toulon, IRD, CNRS, MIO UM 110, 13288, Marseille Cedex 09, France
2 : IFREMER, CNRS, Université de Bretagne Occidentale, Laboratoire de Microbiologie des Environnements Extrêmes-UMR6197, Ifremer, Centre de Brest CS10070, Plouzané, France
3 : Aix Marseille Univ, CNRS, Centrale Marseille, iSm2, Marseille, France
|Source||Scientific Reports (2045-2322) (Springer Science and Business Media LLC), 2021-07 , Vol. 11 , N. 1 , P. 14782 (12p.)|
Deep-sea hydrothermal vents are extreme and complex ecosystems based on a trophic chain. We are still unsure of the identities of the first colonizers of these environments and their metabolism, but they are thought to be (hyper)thermophilic autotrophs. Here we investigate whether the electric potential observed across hydrothermal chimneys could serve as an energy source for these first colonizers. Experiments were performed in a two-chamber microbial electrochemical system inoculated with deep-sea hydrothermal chimney samples, with a cathode as sole electron donor, CO2 as sole carbon source, and nitrate, sulfate, or oxygen as electron acceptors. After a few days of culturing, all three experiments showed growth of electrotrophic biofilms consuming the electrons (directly or indirectly) and producing organic compounds including acetate, glycerol, and pyruvate. Within the biofilms, the only known autotroph species retrieved were members of Archaeoglobales. Various heterotrophic phyla also grew through trophic interactions, with Thermococcales growing in all three experiments as well as other bacterial groups specific to each electron acceptor. This electrotrophic metabolism as energy source driving initial microbial colonization of conductive hydrothermal chimneys is discussed.