Evidence map›Paper›PMID 41987322›Full record

ArticleEnvironmental microbiome2026

Evidence for cable bacteria inhabiting deep in anoxic sediment reveals a novel ecological niche.

Alexis Fonseca, Martijn Hermans, Francisco J A Nascimento, Christian Stranne, Alf Norkko, Bo G Gustafsson, Christoph Humborg

Abstract read
In one paragraph

Article in Environmental microbiome, 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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2 · The registry

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3 · Its place in the literature

Who cites it

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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

7 authors.

Alexis Fonseca *Baltic Sea Centre, Stockholm University, Stockholm, Sweden. alexis.fonseca@su.se.
Martijn Hermans *Baltic Sea Centre, Stockholm University, Stockholm, Sweden. martijn.hermans@su.se.
Francisco J A NascimentoBaltic Sea Centre, Stockholm University, Stockholm, Sweden.
Christian StranneBaltic Sea Centre, Stockholm University, Stockholm, Sweden.
Alf NorkkoTvärminne Zoological Station, University of Helsinki, Hanko, Finland.
Bo G GustafssonBaltic Sea Centre, Stockholm University, Stockholm, Sweden.
Christoph HumborgBaltic Sea Centre, Stockholm University, Stockholm, Sweden.

Funding

No grant is acknowledged in the PubMed record.

6 · The paper itself

Abstract

backgroundCable bacteria are filamentous sulphide-oxidisers capable of cm-scale electron transport. They are generally considered restricted to the upper few oxic-suboxic cm of marine sediments, where they couple sulphide oxidation to oxygen or nitrate reduction. Despite their influence on redox gradients, trace metal mobility, and nutrient cycling, their presence and activity in deeper anoxic sediment layers remain unknown. The presence and activity of marine cable bacteria (Candidatus Electrothrix) were investigated at four stations in Sweden and Finland, including deep vertical profiles of anoxic sediment layers, to assess their presence and activity under different environmental contexts.

resultsUsing metatranscriptomic data for rRNA-based community profiling and gene expression combined with porewater geochemistry, evidence of abundant and active cable bacteria was found, peaking below 20 cm depth in deep anoxic sediment layers of Koljö Fjord on the Swedish West Coast. This zone coincided with elevated gene expressions related to sulphide oxidation (including sqr) and nitrate reduction (napA), as well as an abundant presence of sulphide and a sharp nitrate peak. Phylogenetic analyses revealed a diverse assemblage of Ca. Electrothrix includes several potential novel taxa. The co-occurrence of cable bacteria activity, sulphide availability, and a nitrate peak at depth suggests that these organisms may be supported by local nitrate production under anoxic conditions.

conclusionsOur findings challenge the prevailing view that cable bacteria are restricted to shallow sediment horizons and demonstrate their activity and diversity in deep, anoxic layers. This expands the known ecological niche of cable bacteria and suggests that locally produced nitrate under anoxic conditions may facilitate their activity at depth. This discovery advances our understanding of ecology in anoxic marine environments, providing new insights into marine cable bacteria, sediment biogeochemistry, and analogues of early Earth microbial ecosystems.

Indexed as

Anoxic sedimentsCable bacteriaCandidatus ElectrothrixKoljö fjordMetatranscriptomicNitrate reductionNovel nicheSulfammoxSulphur bacteriaSulphur oxidation

Identifiers

PMID41987322
PMCPMC13081432

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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.