Redox conduction facilitates direct interspecies electron transport in anaerobic methanotrophic consortia
Creators
Abstract
Anaerobic methanotrophic archaea (ANME) and sulfate-reducing bacteria (SRB) form syntrophic partnerships in marine sediments to consume greenhouse gas methane. While direct interspecies electron transport is proposed to enable ANME/SRB symbiosis, its electrochemical properties remain uncharacterized. Here, using sediment-free enrichment cultures, we measured the electron transport capabilities of marine consortia under physiological conditions. Diverse ANME/SRB consortia exhibited high dry conductance close to electrogenic biofilms. This conductance diminished upon exposure to heat or oxygen but was preserved following paraformaldehyde fixation, indicating a biomolecular origin for this electric charge transfer. Cyclic voltammetry revealed redox activity centered at 28 ± 11, 94 ± 6, and 24 ± 7 millivolts for ANME-1/Desulfofervidus, ANME-2a/Seep-SRB1, and ANME-2a+2c/Seep-SRB1+2 consortia, respectively. Generator-collector measurements further demonstrated that these redox components facilitate electron transport over micrometer-scale distances, sufficient to link archaeal and bacterial partners. Collectively, our results establish that marine ANME/SRB symbiosis uses redox conduction, consistent with multiheme cytochrome c, for direct interspecies electron transport.
Copyright and License
© 2025 The Authors, some rights reserved; exclusive licensee American Association for the Advancement of Science. No claim to original U.S. Government Works. Distributed under a Creative Commons Attribution License 4.0 (CC BY).
Acknowledgement
Funding
Work in the M.Y.E.-N. laboratory was supported by the US Department of Energy, Division of Chemical Sciences, Geosciences, and Biosciences, Office of Basic Energy Sciences (DE-FG02-13ER16415) and the Air Force Office of Scientific Research (FA9550-19-1-0249). Work in V.J.O. laboratory was supported by the US Department of Energy, Office of Science, Office of Biological and Environmental Research (DE-SC0022991). Work in H.Y. laboratory was supported by the National Natural Science Foundation of China (no. 42377109). Work in G.W. laboratory was supported by Germany’s Excellence Initiative/Strategy through the Cluster of Excellence “The Ocean Floor-Earth’s Uncharted Interface” (EXC-2077–390741603).
Data Availability
The 16S rRNA gene amplicon sequences from the sediment-free enrichment cultures have been deposited in the National Center for Biotechnology Information (NCBI) under BioProject accession no. PRJNA758896 (www.ncbi.nlm.nih.gov/sra/PRJNA758896). All other data needed to evaluate the conclusions in the paper are present in the paper and/or the Supplementary Materials.
Supplemental Material
Figs. S1 to S7 (PDF)
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sciadv.adw4289.pdf
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Additional details
Identifiers
- PMID
- 40845095
- PMCID
- PMC12372872
Related works
- Describes
- Journal Article: 40845095 (PMID)
- Journal Article: PMC12372872 (PMCID)
- Is supplemented by
- Dataset: http://www.ncbi.nlm.nih.gov/sra/PRJNA758896 (URL)
- Supplemental Material: https://www.science.org/doi/suppl/10.1126/sciadv.adw4289/suppl_file/sciadv.adw4289_sm.pdf (URL)
Funding
- United States Department of Energy
- DE-FG02-13ER16415
- United States Air Force Office of Scientific Research
- FA9550-19-1-0249
- United States Department of Energy
- DE-SC0022991
- National Natural Science Foundation of China
- 42377109
- Deutsche Forschungsgemeinschaft
- EXC-2077–390741603
Dates
- Accepted
-
2025-07-22