Evidence map›Paper›PMID 41764643›Full record

ArticleThe ISME journal2026

Redox gradients define the ecological niche of ciliates with denitrifying endosymbionts in anoxic lake waters.

Linus M Zeller, Sina Schorn, Louison Nicolas-Asselineau, Jakob Zopfi, Soeren Ahmerkamp, Carsten J Schubert, Fabio Lepori, Marcel M M Kuypers, Jon S Graf, Jana Milucka

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Article in The ISME journal, 2026. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Not yet cited in PubMed.

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0citing papers in PubMed
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1 · What the graph read from it

What it found

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The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.

2 · The registry

The trial behind it

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3 · Its place in the literature

Who cites it

0 citing papers in PubMed.

No citing paper in PubMed yet.

4 · The record

Corrections and comments

PubMed lists nothing against this paper. Absence here is not a guarantee, only a check that was made.

5 · Who and what money

Authors and funding

10 authors.

Linus M ZellerDepartment of Biogeochemistry, Max Planck Institute for Marine Microbiology, 28359 Bremen, Germany.
Sina SchornDepartment of Biogeochemistry, Max Planck Institute for Marine Microbiology, 28359 Bremen, Germany.
Louison Nicolas-AsselineauDepartment of Biogeochemistry, Max Planck Institute for Marine Microbiology, 28359 Bremen, Germany.ORCID 0009-0000-3818-4966
Jakob ZopfiDepartment of Environmental Sciences, University of Basel, 4056 Basel, Switzerland.ORCID 0000-0002-8437-7344
Soeren AhmerkampDepartment of Biogeochemistry, Max Planck Institute for Marine Microbiology, 28359 Bremen, Germany.
Carsten J SchubertDepartment of Surface Waters-Research and Management, Swiss Federal Institute of Aquatic Science and Technology (EAWAG), 6047 Kastanienbaum, Switzerland.
Fabio LeporiInstitute of Earth Sciences, University of Applied Sciences and Arts of Southern Switzerland (SUPSI), 6850 Mendrisio, Switzerland.
Marcel M M KuypersDepartment of Biogeochemistry, Max Planck Institute for Marine Microbiology, 28359 Bremen, Germany.
Jon S GrafDepartment of Biogeochemistry, Max Planck Institute for Marine Microbiology, 28359 Bremen, Germany.
Jana MiluckaDepartment of Biogeochemistry, Max Planck Institute for Marine Microbiology, 28359 Bremen, Germany.

Funding

internal funds of EawagMax Planck Society
6 · The paper itself

Abstract

Bacterial endosymbionts of the family Candidatus Azoamicaceae obligately associate with anaerobic ciliates belonging to the class Plagiopylea. The symbionts' unique role for their host involves anaerobic respiration of nitrate and generation of adenosine triphosphate (ATP), analogous to the role of mitochondria in aerobic eukaryotes. As this symbiosis remains so far uncultured, insights into its functioning have been mainly inferred from environmental metagenomes. Here, we investigated the distribution and environmental role of this symbiosis in the anoxic basins of two freshwater lakes, Zug and Lugano (Switzerland), over a course of several years. We found that the environmental niche of the ciliate host is defined by the combined effects of sulfide, oxygen, and nitrate, the latter of which is essential for the symbiont's respiratory function. Moreover, the distribution and abundance of ciliates with denitrifying endosymbionts in the water column suggest that they may substantially contribute to nitrate consumption in Lake Zug. Our microscopic analyses further demonstrated a coordinated division of the Ca. Azoamicus ciliaticola symbionts and their ciliate hosts, implying a vertical inheritance of denitrifying symbionts. These observations offer new insights into the evolution of ciliates with denitrifying endosymbionts and their ecological role in oxygen-depleted lake waters.

Indexed as

CiliophoraLakesSymbiosisAnaerobiosisDenitrificationEcosystemMolecular Sequence DataNitratesOxidation-ReductionOxygenPhylogenySequence Analysis, DNASulfidesSwitzerlandNitratesOxygenSulfidesanoxicciliatesendosymbiosismeromictic lakesprotists

Identifiers

PMID41764643
PMCPMC13037464

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Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the OpenQuestion graph.