Dissimilatory sulfate reduction in the archaeon ‘Candidatus Vulcanisaeta moutnovskia’ sheds light on the evolution of sulfur metabolism

Dissimilatory sulfate reduction (DSR)—an important reaction in the biogeochemical sulfur cycle—has been dated to the Palaeoarchaean using geological evidence, but its evolutionary history is poorly understood. Several lineages of bacteria carry out DSR, but in archaea only Archaeoglobus, which acquired DSR genes from bacteria, has been proven to catalyse this reaction. We investigated substantial rates of sulfate reduction in acidic hyperthermal terrestrial springs of the Kamchatka Peninsula and attributed DSR in this environment to Crenarchaeota in the Vulcanisaeta genus. Community profiling, coupled with radioisotope and growth experiments and proteomics, confirmed DSR by ‘Candidatus Vulcanisaeta moutnovskia’, which has all of the required genes. Other cultivated Thermoproteaceae were briefly reported to use sulfate for respiration but we were unable to detect DSR in these isolates. Phylogenetic studies suggest that DSR is rare in archaea and that it originated in Vulcanisaeta, independent of Archaeoglobus, by separate acquisition of qmoABC genes phylogenetically related to bacterial hdrA genes.This work was supported by the Russian Science Foundation (grant number 17-74-30025) and in part by the grant from the Russian Ministry of Science and Higher Education (to N.A.C., A.V.L., E.N.F., M.L.M., A.Y.M., N.V.P. and E.A.B.-O.). Sequencing of PCR amplicons was performed using the scientific equipment of the core research facility ‘Bioengineering’ by T. Kolganova. The proteomics analysis was performed at the Proteomics Facility of the Spanish National Center for Biotechnology (CNB-CSIC), which belongs to ProteoRed, PRB2-ISCIII, supported by grant PT13/0001 (to S.C., M.C.M. and M.F.). P.N.G. acknowledges funding from the UK Biotechnology and Biological Sciences Research Council (BBSRC) within the ERA NET-IB2 programme, grant number ERA-IB-14-030 and the European Union Horizon 2020 Research and Innovation programme (Blue Growth: Unlocking the Potential of Seas and Oceans) under grant agreement number 634486, as well as support from the Centre for Environmental Biotechnology project, part funded by the European Regional Development Fund (ERDF) through the Welsh Government, and support from the Centre of Environmental Biotechnology. D.Y.S. was supported by the SIAM/Gravitation Program (Dutch Ministry of Education, Culture and Science; grant 24002002) and RFBR grant 19-04-00401. F.L.S. and S.N. acknowledge support from the Wiener Wissenschafts, Forschungs- und Technologiefonds (Austria) through the grant VRG15-007. F.L.S. gratefully acknowledges funding from the European Research Council (ERC) under the European Union’s Horizon 2020 Research and Innovation programme (grant agreement 803768). I.A.C.P. acknowledges support from the Fundação para a Ciência e Tecnologia (Portugal) through grant PTDC/BIA-BQM/29118/2017 and R&D unit MOSTMICRO-ITQB (UIDB/04612/2020 and UIDP/04612/2020)

Complete Genome Sequence of the Hyperthermophilic Archaeon Thermococcus sp Strain AM4, Capable of Organotrophic Growth and Growth at the Expense of Hydrogenogenic or Sulfidogenic Oxidation of Carbon Monoxide

International audienceAnalysis of the complete genome of Thermococcus sp. strain AM4, which was the first lithotrophic Thermococcales isolate described and the first archaeal isolate to exhibit a capacity for hydrogenogenic carboxydotrophy, reveals a proximity with Thermococcus gammatolerans, corresponding to close but distinct species that differ significantly in their lithotrophic capacities