SEM — Coccoid cells with surface filaments growing on insoluble Fe(III) oxides. Adapted from Manzella MP et al. (2015), Stand Genomic Sci 10:77, Fig. 2. Source · CC BY 4.0 · None to content (single-panel figure extracted from the article PDF); converted to WebP

Electrogen · Iron reducer

Geoglobus ahangari strain 234

Euryarchaeota · Archaeoglobi · Archaeoglobaceae

ElectroactiveEET outwardBSL-1Stub record
  • Archaea
  • Hyperthermophile
  • Novel EET
  • Tier 3
Outward
Electron transfer
electroactive
88°C
Optimal temperature
grows 65–90 °C
7
Optimal pH
grows pH 5–7.6

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. ›phylumEuryarchaeota
  3. ›classArchaeoglobi
  4. ›orderArchaeoglobales
  5. ›familyArchaeoglobaceae
  6. ›genusGeoglobus
  7. ›speciesGeoglobus ahangari 234

Culture collections & accessions

NCBI taxon
113653

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 outward
CELLELECTRODEOUTER-MEMBRANE CYTOCHROMESe⁻NANOWIRE · PILA PILINe⁻
Electrons flow outward: cell → electrode (exoelectrogen)

Mechanisms

  • Outer-membrane cytochromes: yes
  • Conductive pili / nanowires: yes

03 · Growth envelope

Growth envelope

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

HyperthermophileObligate anaerobeChemoorganoheterotroph
Temperature88 (65–90) °C
0100 °C
pH7 (5–7.6)
014
Salinity27 (10–50) g/L
0100 g/L

Energy metabolism

Electron donors

  • Acetate
  • H2
  • fatty acids

Electron acceptors

  • Fe(III)
  • Anode

Carbon sources

  • Acetate
  • Pyruvate
  • Lactate
  • long-chain fatty acids

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 μmax0.05 h⁻¹0.01–0.121genus prior · 0 refs
Half-saturation constant Ks50 mg/L10–1501genus prior · 0 refs
Biomass yield Y0.05 g/g0.02–0.11genus prior · 0 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: Geoglobus ahangari

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.

    0.6g/m²
    Peak biomass
    37.5h
    Time to 90 % substrate removal
    Attached biomassg/m²
    00.250.50204060h
    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
    • Slowing
    • Stationary

    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.

    Moderate electrogen

    06 · Ecology & biofilm

    Ecology & biofilm

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

    Ecosystems

    • Marine
    • Extreme environment
    • Hydrothermal vent

    Isolation sources

    • hydrothermal vent, Guaymas Basin

    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)

    • Research model organism

    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

    StubMedium confidenceNeeds reviewCurated: manual

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

    References (1)

    1. Manzella MP, et al. (2013). EET to Fe(III) by Geoglobus ahangari. Appl Environ Microbiol 79:4694-4700.doi:10.1128/AEM.01566-13