SEM — Cell clusters in close association with (Ni,Fe)S2 nanoparticles during growth on acetate and methanol. Adapted from Spietz RL, Payne D, Boyd ES (2023), Appl Environ Microbiol 89:e00991-23, Fig. 3. Source · CC BY 4.0 · None (single-panel figure taken at native resolution from the article PDF; converted to WebP)

Methanogen acetoclastic · Methanogen hydrogenotrophic · Methanogen methylotrophic

Methanosarcina barkeri Fusaro

Halobacteriota · Methanosarcinia · Methanosarcinaceae

ElectroactiveEET inwardBSL-1Partial record
  • Methanogen
  • DIET partner
  • Electromethanogenesis
  • Tier 1
Inward
Electron transfer
electroactive
35°C
Optimal temperature
grows 25–40 °C
7
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. ›phylumHalobacteriota
  3. ›classMethanosarcinia
  4. ›orderMethanosarcinales
  5. ›familyMethanosarcinaceae
  6. ›genusMethanosarcina
  7. ›speciesMethanosarcina barkeri Fusaro

Culture collections & accessions

NCBI taxon
269797

Cell morphology

Sarcina packets · Archaeal s layer only

  • Motile: 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
CELLPARTNERDIET → G. metallireducense⁻
Electrons flow inward: electrode → cell (electrotroph)

Mechanisms

Direct transfer — detail

Notes
Rotaru et al. (2014) report direct cathode electron uptake. Subsequent work shows much of the current is mediated via abiotically generated H2; the genuine DET fraction remains contested.
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
Temperature35 (25–40) °C
0100 °C
pH7 (6.5–7.5)
014

Energy metabolism

Electron donors

  • H2
  • Acetate
  • Methanol
  • Cathode

Electron acceptors

  • CO2

Carbon sources

  • Acetate
  • CO2
  • Methanol
  • Methylamines

Metabolism — detail

Carbon fixation pathway
Wood ljungdahl

04 · Growth & electron-transfer kinetics

Growth & electron-transfer kinetics

How fast this organism grows and how hard it pushes electrons into an anode, as the corpus reports it, and what those constants imply when you run them.

Kinetic evidence

ParameterMedian10–90 %nSource
Max. specific growth rate μmax0.015 h⁻¹0.005–0.044genus prior · 2 refs
Half-saturation constant Ks200 mg/L50–6002genus prior · 2 refs
Biomass yield Y0.03 g/g0.01–0.052genus prior · 2 refs
Decay coefficient kdNot in the corpus yet
Exchange current density i₀Not in the corpus yet
Transfer coefficient αNot in the corpus yet
Tafel slopeNot in the corpus yet

Median of the extracted values, the 10–90 % spread behind it and how many values it pools.

Evidence rows (0)

Genus-level prior: Methanosarcina barkeri

A genus-level prior is a summary for the whole genus, not a measurement on this strain.

Constants that drive the simulation

Scenario — values you set, not evidence

Initial substrate1000 mg/L
Anode potential vs SHE0 V
Duration72 h
Initial attached biomass0.1 g/m²
Anode area per liquid volume100 m²/m³
Reactor mode

Growth simulation

Scenario: Initial substrate 1000 mg/L · Initial attached biomass 0.1 g/m² · Anode area per liquid volume 100 m²/m³ · Duration 72 h · Batch. Values you set, not evidence.

0.236g/m²
Peak biomass
545.5mg/L
Final substrate
Time to 90 % substrate removal: not reached
Attached biomassg/m²
00.20204060h
Bulk substratemg/L
050010000204060h

No current model

The current needs Max. current density jmax, Half-saturation potential E_KA, which this source does not have.

  • Substrate-saturated growth

Monod growth has no lag phase; the bands mark where the net growth rate is near its maximum, falling, near zero or negative.

Simulator notes
  • decayPerH absent: no endogenous decay term, so growth is an upper bound
  • biofilmDensityKgPerM3 absent: thickness not computed (thicknessUm = null)
  • no anodePotentialVvsShe / overpotentialV given: current not computed (currentDensityAPerM2 = null)

These curves are a Monod and Nernst-Monod idealisation (after Marcus et al. 2007 and Torres et al. 2008), parameterised only by the constants listed above: each one carries its n and its 10–90 % range, and a constant with n = 1 has no spread at all. No diffusion inside the biofilm, no detachment, no coulombic-efficiency split. The scenario values are yours, not evidence.

05 · 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 titerg/LMax rateCoulombic efficiency
methane———

06 · Ecology & biofilm

Ecology & biofilm

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

Electron-exchange partners (1)

Ecosystems

  • Anaerobic digester
  • Freshwater
  • Rice paddy
  • Sediment freshwater

07 · 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 · Bench scale
    TRL 4/9

Biosafety

BSL-1
  • Pathogen: no

08 · 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 H2-mediated cathode uptake: contested fraction. Reports use mixed conventions for 'direct' vs 'indirect'.
  • Pure-culture electromethanogenesis rates rarely reported with sufficient gas-headspace controls.

References (2)

  1. Cheng S, et al. (2009). Direct biological conversion of electrical current into methane by electromethanogenesis. Environ Sci Technol 43:3953-3958.doi:10.1021/es803531g
  2. Rotaru AE, et al. (2014). A new model for electron flow during anaerobic digestion: direct interspecies electron transfer to Methanosaeta for the reduction of carbon dioxide to methane. Energy Environ Sci 7:408-415.doi:10.1039/C3EE42189A