TY - JOUR
T1 - The possible occurrence of iron-dependent anaerobic methane oxidation in an Archean Ocean analogue
AU - Roland, Fleur A.E.
AU - Borges, Alberto V.
AU - Darchambeau, François
AU - Llirós, Marc
AU - Descy, Jean Pierre
AU - Morana, Cédric
N1 - Funding Information:
We thank the team of the Observatoire volcanologique de Goma (OVG) for their involvement in sampling, Bo Thamdrup (University of Southern Denmark) for the access to his laboratory, Bruno Leporcq (University of Namur), Renzo Biondo (University of Liège), Dina Holmgaard Skov and Heidi Grøn Jensen (University of Southern Denmark) for help in measurements, Jack Middelburg and Steven Bouillon for comments on the draft and the three anonymous reviewers and associated editor for their valuable contribution. We also thank Thibault Lambert (University of Liège) for the elaboration of the map (Figure S1). This study was funded by the Belgian Federal Science Policy Office (BELSPO, Belgium) under the EAGLES (East African Great lake Ecosystem Sensitivity to Changes, SD/AR/02A) project, by the Fonds National de la Recherche Scientifique (FNRS) under the MICKI (Microbial diversity and processes in Lake Kivu, 1715859) project, and contributes to the European Research Council (ERC) starting grant project AFRIVAL (African river basins: Catchment-scale carbon fluxes and transformations, 240002). GC apparatus was acquired with funds from the FNRS (Contract No. 2.4.598.07). AVB is a senior research associate at the FNRS. FAER had a PhD grant from FNRS (« Fonds pour la formation à la Recherche dans l’Industrie et dans l’Agriculture »—FRIA) and is now post-doctoral researcher at the FNRS (Project No. X.3007.17 funded by the Walloon Institute of Sustainable Development). This study shows results mainly obtained during FAER’s Ph.D., and the “Material and methods” section has been mostly described in the resulting unpublished thesis.
Publisher Copyright:
© 2021, The Author(s).
Copyright:
Copyright 2021 Elsevier B.V., All rights reserved.
PY - 2021/1
Y1 - 2021/1
N2 - In the ferruginous and anoxic early Earth oceans, photoferrotrophy drove most of the biological production before the advent of oxygenic photosynthesis, but its association with ferric iron (Fe3+) dependent anaerobic methane (CH4) oxidation (AOM) has been poorly investigated. We studied AOM in Kabuno Bay, a modern analogue to the Archean Ocean (anoxic bottom waters and dissolved Fe concentrations > 600 µmol L−1). Aerobic and anaerobic CH4 oxidation rates up to 0.12 ± 0.03 and 51 ± 1 µmol L−1 d−1, respectively, were put in evidence. In the Fe oxidation–reduction zone, we observed high concentration of Bacteriochlorophyll e (biomarker of the anoxygenic photoautotrophs), which co-occurred with the maximum CH4 oxidation peaks, and a high abundance of Candidatus Methanoperedens, which can couple AOM to Fe3+ reduction. In addition, comparison of measured CH4 oxidation rates with electron acceptor fluxes suggest that AOM could mainly rely on Fe3+ produced by photoferrotrophs. Further experiments specifically targeted to investigate the interactions between photoferrotrophs and AOM would be of considerable interest. Indeed, ferric Fe3+-driven AOM has been poorly envisaged as a possible metabolic process in the Archean ocean, but this can potentially change the conceptualization and modelling of metabolic and geochemical processes controlling climate conditions in the Early Earth.
AB - In the ferruginous and anoxic early Earth oceans, photoferrotrophy drove most of the biological production before the advent of oxygenic photosynthesis, but its association with ferric iron (Fe3+) dependent anaerobic methane (CH4) oxidation (AOM) has been poorly investigated. We studied AOM in Kabuno Bay, a modern analogue to the Archean Ocean (anoxic bottom waters and dissolved Fe concentrations > 600 µmol L−1). Aerobic and anaerobic CH4 oxidation rates up to 0.12 ± 0.03 and 51 ± 1 µmol L−1 d−1, respectively, were put in evidence. In the Fe oxidation–reduction zone, we observed high concentration of Bacteriochlorophyll e (biomarker of the anoxygenic photoautotrophs), which co-occurred with the maximum CH4 oxidation peaks, and a high abundance of Candidatus Methanoperedens, which can couple AOM to Fe3+ reduction. In addition, comparison of measured CH4 oxidation rates with electron acceptor fluxes suggest that AOM could mainly rely on Fe3+ produced by photoferrotrophs. Further experiments specifically targeted to investigate the interactions between photoferrotrophs and AOM would be of considerable interest. Indeed, ferric Fe3+-driven AOM has been poorly envisaged as a possible metabolic process in the Archean ocean, but this can potentially change the conceptualization and modelling of metabolic and geochemical processes controlling climate conditions in the Early Earth.
UR - http://www.scopus.com/inward/record.url?scp=85099472305&partnerID=8YFLogxK
U2 - 10.1038/s41598-021-81210-x
DO - 10.1038/s41598-021-81210-x
M3 - Article
AN - SCOPUS:85099472305
SN - 2045-2322
VL - 11
JO - Scientific Reports
JF - Scientific Reports
IS - 1
M1 - 1597
ER -