biostudies-literatureMcNichol JGouvernement du Canada | Natural Sciences and Engineering Research Council of CanadaCanadian Meteorological and Oceanographic SocietyNational Aeronautics and Space AdministrationNational Science Foundatione0208321https://www.ebi.ac.uk/biostudies/studies/S-EPMC8788762biostudies-literatureUnknown88(2)Molecular surveys of low temperature deep-sea hydrothermal vent fluids have shown that <i>Campylobacteria</i> (previously <i>Epsilonproteobacteria</i>) often dominate the microbial community and that three genera, <i>Arcobacter</i>, <i>Sulfurimonas</i>, and <i>Sulfurovum</i>, frequently coexist. In this study, we used replicated radiocarbon incubations of deep-sea hydrothermal fluids to investigate activity of each genus under three experimental conditions. To quantify genus-specific radiocarbon incorporation, we used newly designed oligonucleotide probes for <i>Arcobacter</i>, <i>Sulfurimonas</i>, and <i>Sulfurovum</i> to quantify their activity using catalyzed-reporter deposition fluorescence <i>in situ</i> hybridization (CARD-FISH) combined with fluorescence-activated cell sorting. All Applied and environmental microbiologyGenus-Specific Carbon Fixation Activity Measurements Reveal Distinct Responses to Oxygen among Hydrothermal Vent <i>Campylobacteria</i>.PMC8788762OCE-1136727OCE-1131095PGSM-405117-2011PGSD3- 430487-2013PLANET14F-0075Dyksma SSeewald JSSylva SPSievert SMMcNichol JMußmann MfalseGenus-Specific Carbon Fixation Activity Measurements Reveal Distinct Responses to Oxygen among Hydrothermal Vent <i>Campylobacteria</i>.Molecular surveys of low temperature deep-sea hydrothermal vent fluids have shown that <i>Campylobacteria</i> (previously <i>Epsilonproteobacteria</i>) often dominate the microbial community and that three genera, <i>Arcobacter</i>, <i>Sulfurimonas</i>, and <i>Sulfurovum</i>, frequently coexist. In this study, we used replicated radiocarbon incubations of deep-sea hydrothermal fluids to investigate activity of each genus under three experimental conditions. To quantify genus-specific radiocarbon incorporation, we used newly designed oligonucleotide probes for <i>Arcobacter</i>, <i>Sulfurimonas</i>, and <i>Sulfurovum</i> to quantify their activity using catalyzed-reporter deposition fluorescence <i>in situ</i> hybridization (CARD-FISH) combined with fluorescence-activated cell sorting. All 2022-01-01T00:00:00Z2022 Jan2026-06-07T07:30:01.439Z2025-04-04T07:50:54.675ZS-EPMC87887623478806110.1128/AEM.02083-2110.1128/aem.02083-21