MESSAI.iO

Methanogen hydrogenotrophic · Electrotroph · N₂ fixer

Methanococcus maripaludis S2

Methanobacteriota · Methanococci · Methanococcaceae

ElectroactiveEET inwardBSL-1Partial record
  • Methanogen
  • Marine
  • Halotolerant
  • Tier 2
  • Contested EET
Inward
Electron transfer
electroactive
37°C
Optimal temperature
grows 20–45 °C
6.9
Optimal pH
grows pH 6.5–7.5

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. ›phylumMethanobacteriota
  3. ›classMethanococci
  4. ›orderMethanococcales
  5. ›familyMethanococcaceae
  6. ›genusMethanococcus
  7. ›speciesMethanococcus maripaludis S2

Culture collections & accessions

NCBI taxon
267377

Cell morphology

Coccus · Archaeal s layer only

  • Motile: yes

02 · Electron transfer

Electron transfer

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

ElectroactiveEET inward

No extracellular electron-transfer route is curated for this organism yet.

Mechanisms

Direct transfer — detail

Notes
Lohner et al. (2014) reported H2-independent cathodic methane production via Hdr-related pathways; later work (Deutzmann et al. 2015) showed much of the current under those conditions is mediated by extracellularly released hydrogenases / formate dehydrogenases that catalyze H2/formate generation at the cathode. Practical implication for kinetic priors: treat as 'mediated' by default.
Completeness
Contested

Other

Cathode electron uptake mechanism
Contested

03 · Growth envelope

Growth envelope

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

Obligate anaerobeChemolithoautotroph
Temperature37 (20–45) °C
0100 °C
pH6.9 (6.5–7.5)
014
Salinity25 (10–40) g/L
050 g/L

Energy metabolism

Electron donors

  • H2
  • Formate
  • Cathode

Electron acceptors

  • CO2

Carbon sources

  • CO2
  • Formate

Metabolism — detail

N₂ fixation
Yes
Carbon fixation pathway
Wood ljungdahl

04 · Performance

Performance

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

Role in a reactor

Cathode chamberCathode: primary product producer

Products (1)

ProductMax titer (g/L)Max rateCoulombic efficiency
methane———

05 · Ecology & biofilm

Ecology & biofilm

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

Ecosystems

  • Marine
  • Sediment marine

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)

  • Microbial electrosynthesis methane
    TRL 3/9

Biosafety

BSL-1
  • Pathogen: no

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

PartialMedium confidenceCurated: manual

Literature reviewed 2026-05-13 · schema v1.3.0 · updated 2026-05-13 · imported 2026-05-13

Open data gaps (2)

  • 'Direct' vs hydrogenase-mediated cathode uptake debate unresolved.
  • Genetic tractability is excellent but biochemical mapping of EET path incomplete.

References (2)

  1. Lohner ST, et al. (2014). Hydrogenase-independent uptake and metabolism of electrons by the archaeon Methanococcus maripaludis. ISME J 8:1673-1681.doi:10.1038/ismej.2014.82
  2. Deutzmann JS, Sahin M, Spormann AM (2015). Extracellular enzymes facilitate electron uptake in biocorrosion and bioelectrosynthesis. mBio 6:e00496-15.doi:10.1128/mBio.00496-15