MESSAI.iO

Methanogen acetoclastic · DIET partner acceptor

Methanothrix harundinacea

Also known as Methanosaeta harundinacea

Halobacteriota · Methanosarcinia · Methanotrichaceae

ElectroactiveEET inwardType strainBSL-1Partial record
  • Methanogen
  • Archaea
  • DIET acceptor
  • Anaerobic digester
  • Tier 1
  • Competitor in MFC
Inward
Electron transfer
electroactive
35°C
Optimal temperature
grows 25–40 °C
7
Optimal pH
grows pH 6.5–8

01 · Identity

Identity

Where this organism sits in the tree of life, how to obtain it, and what a cell looks like.

Lineage

  1. domainArchaea
  2. ›phylumHalobacteriota
  3. ›classMethanosarcinia
  4. ›orderMethanosarcinales
  5. ›familyMethanotrichaceae
  6. ›genusMethanothrix
  7. ›speciesMethanothrix harundinacea

Formerly classified as Methanosaeta harundinacea.

Culture collections & accessions

Status
Type strain

Cell morphology

Multicellular filament · Archaeal pseudomurein

  • Motile: no
  • Spore-forming: no

02 · Electron transfer

Electron transfer

How electrons cross the cell envelope — the property that makes a microbe useful in an electrochemical system.

ElectroactiveEET inward
CELLELECTRODENANOWIRE · UNKNOWNe⁻DIET → G. metallireducense⁻
Electrons flow inward: electrode → cell (electrotroph)

Mechanisms

  • Outer-membrane cytochromes: no

Direct transfer — detail

Notes
DIET mechanism not via cytochromes — exact electrical contact unknown.

Other

Cathode electron uptake mechanism
Direct EET demonstrated

03 · Growth envelope

Growth envelope

The conditions this organism tolerates and what it eats and breathes — the operating window for a reactor.

MesophileObligate anaerobeChemoorganoheterotroph
Temperature35 (25–40) °C
0100 °C
pH7 (6.5–8)
014
Doubling time168 h
0250 h

Slow growers (~7 days).

Energy metabolism

Electron donors

  • Acetate
  • electrons via DIET from Geobacter

Electron acceptors

  • CO2

Carbon sources

  • Acetate
  • CO2 (via DIET)
  • Fermentative: no

Metabolism — detail

ATP synthase type
Sodium dependent
Energy conservation mechanism
Wood ljungdahl

04 · Performance

Performance

Reported electrochemical output, the role it plays in a reactor, and what it produces.

Role in a reactor

No preferred chamberAnode: competitor
Typical relative abundance in biofilm60 (30–90) %
0100 %

Dominant methanogen in many anaerobic digesters.

Substrate → product (4)

  • acetateyields
    • CH4
    • CO2

    anaerobic · Acetoclastic methanogenesis.

  • acetateyields
    • CH4
    • CO2

    anaerobic · Acetoclastic methanogenesis.

  • electrons (from Geobacter via DIET) + CO2yields
    • CH4

    co-culture · DIET-driven methanogenesis.

  • electrons (from Geobacter via DIET) + CO2yields
    • CH4

    co-culture · DIET-driven methanogenesis.

05 · Ecology & biofilm

Ecology & biofilm

How it lives on an electrode, who it partners with, and where it is found in nature.

Electron-exchange partners (2)

Conductive-mineral mediation

  • Mediates via conductive minerals: yes
  • Magnetite
  • Biochar
  • Activated carbon

Multiple studies show magnetite/biochar amendment accelerates DIET-coupled methanogenesis with Geobacter partners (Rotaru 2014, Cruz Viggi 2014).

Ecosystems

  • Anaerobic digester
  • Rice paddy
  • Wastewater
  • Freshwater

Isolation sources

  • anaerobic digester sludge
  • rice paddy soil
  • freshwater sediment

06 · Applications, engineering & safety

Applications, engineering & safety

Where it has been put to work, how tractable it is to engineer, and what handling it requires.

Applications (1)

  • Wastewater treatment · Commercial

    Dominant in anaerobic digestion at municipal scale.

    TRL 9/9

Biosafety

BSL-1
  • Pathogen: no

Modeling assets

Linked GEM: iMT-harundinacea

07 · Sources & data quality

Sources & data quality

Every value above traces to a citation. This is how complete and how confident the record is.

Record quality

PartialHigh confidenceCurated: manual

Literature reviewed 2026-04-26 · schema v1.2.0 · updated 2026-04-28 · imported 2026-04-28

Open data gaps (1)

  • Electrical contact protein for DIET unknown

References (4)

  1. Rotaru AE, et al. (2014). A new model for electron flow during anaerobic digestion: DIET to Methanosaeta. Energy Environ Sci 7:408-415.doi:10.1039/C3EE42189A
  2. Rotaru AE, et al. (2014). A new model for electron flow during anaerobic digestion: DIET to Methanosaeta. Energy Environ Sci 7:408-415.doi:10.1039/C3EE42189A
  3. Holmes DE, et al. (2017). Metatranscriptomic evidence for DIET between Geobacter and Methanothrix in rice paddy soils. Appl Environ Microbiol 83:e00223-17.doi:10.1128/AEM.00223-17
  4. Holmes DE, et al. (2017). Metatranscriptomic evidence for DIET between Geobacter and Methanothrix in rice paddy soils. Appl Environ Microbiol 83:e00223-17.doi:10.1128/AEM.00223-17

Version history

  1. 2026-04-27 · v1.2.0 · messai_curation
    • Added conductive_mineral_mediation evidence (magnetite, biochar).
    • Added energy_conservation_mechanism: wood_ljungdahl.
    • Confirmed former_classification: Methanosaeta harundinacea.