Electrogen · Bidirectional EET · DIET partner donor
Geobacter sulfurreducens PCA
Thermodesulfobacteriota · Desulfuromonadia · Geobacteraceae
- Model organism
- Anode respiring
- Metal reducer
- Tier 1
- DIET donor
01 · Identity
Identity
Where this organism sits in the tree of life, how to obtain it, and what a cell looks like.
Lineage
- domainBacteria
- ›phylumThermodesulfobacteriota
- ›classDesulfuromonadia
- ›orderGeobacterales
- ›familyGeobacteraceae
- ›genusGeobacter
- ›speciesGeobacter sulfurreducens PCA
Formerly classified as Deltaproteobacteria.
Culture collections & accessions
- DSMZ
- DSM 12127
- ATCC
- ATCC 51573
- NCBI taxon
- 243231
- Genome
- GCF_000007985.2
- Status
- Type strain
Isolation
From Potomac River sediment, Maryland, USA by Caccavo F. et al. (1994).
Caccavo F, et al. (1994). Geobacter sulfurreducens sp. nov. PubMed
Genome
Cell morphology
Rod, Gram-negative (diderm)
length 2.5 (1.5–4) µm · width 0.5 (0.4–0.7) µm
- Motile: no
- Pili: yes
- Capsule: no
- S-layer: no
- Outer-membrane vesicles: 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.
Mechanisms
- Outer-membrane cytochromes: yes
- Conductive pili / nanowires: yes
- Endogenous shuttles: no
- Exogenous shuttles: no
Nanowire conductivity 0.028 (0.001–0.5) S/cm
OmcS filament intrinsic conductivity ~28 mS/cm; values vary widely with measurement method (network vs single-filament). See Wang 2019, Yalcin 2020.
Redox ladder
- 1OmcZ -0.22 V · Extracellular · 8 hemes
- 2OmcS -0.212 V · Nanowire filament · 6 hemes
- 3OmcB -0.19 V · Outer membrane · 12 hemes
- 4PpcA -0.15 V · Periplasm · 3 hemes
Cytochromes (14)
| Name | Location | Hemes | E°′ (V) | Structure |
|---|---|---|---|---|
| CbcL | Inner membrane | 9 | — | — Required for low-potential (≤−0.1 V) electron transfer. |
| ImcH | Inner membrane | 6 | — | — Inner-membrane cytochrome required for high-potential acceptors. |
| OmaB | Outer membrane | — | — | — Component of the OmaB-OmbB porin-cytochrome complex. |
| OmaC | Outer membrane | — | — | — Component of the OmaC-OmbC porin-cytochrome complex. |
| OmbB | Outer membrane | — | — | — β-barrel porin partner of OmaB. |
| OmbC | Outer membrane | — | — | — β-barrel porin partner of OmaC. |
| OmcB | Outer membrane | 12 | -0.19 | — Outer-membrane dodecaheme; required for Fe(III) citrate reduction. |
| OmcC | Outer membrane | 12 | — | — Paralog of OmcB; less essential phenotypically. |
| OmcE | Nanowire filament | 4 | — | — Tetraheme nanowire identified by cryo-EM (Wang 2022). |
| OmcS | Nanowire filament | 6 | -0.212 | PDB 6EF8EMDB EMD-9046 Forms the canonical conductive nanowire filament (Wang 2019). |
| OmcZ | Extracellular | 8 | -0.22 | PDB 7TFS Octaheme; high-current-density biofilm filament (Yalcin 2020). |
| PpcA | Periplasm | 3 | -0.15 | — Periplasmic triheme; central to Fe(III) and U(VI) reduction. |
| PpcB | Periplasm | 3 | — | — PpcA paralog. |
| PpcD | Periplasm | 3 | — | — PpcA paralog. |
Direct transfer — detail
- Completeness
- Mapped
- Nanowire length
- 5 (1–20) µm
Mediated transfer — detail
- Completeness
- Mapped
03 · Growth envelope
Growth envelope
The conditions this organism tolerates and what it eats and breathes — the operating window for a reactor.
Energy metabolism
Electron donors
- Acetate
- H2
- Formate
Electron acceptors
- Fe(III)
- Mn(IV)
- Fumarate
- Anode
- S0
- U(VI)
Carbon sources
- Acetate
- Hydrogen
- Formate
- Lactate
- Pyruvate
- Respiratory: yes
- Fermentative: no
Metabolism — detail
- ATP synthase type
- Proton dependent
- Energy conservation mechanism
- Oxidative phosphorylation
- Lag phase
- 1 h
04 · Performance
Performance
Reported electrochemical output, the role it plays in a reactor, and what it produces.
- Onset potential
- -0.17 V vs SHE
Role in a reactor
Often dominates acetate-fed anode biofilms after enrichment.
Substrate → product (2)
- acetateyields
- CO2
anaerobic, anode as electron acceptor · yield 8 electrons/mol acetate · Complete oxidation to CO2.
- acetateyields
- CO2
anaerobic, anode as electron acceptor · yield 8 electrons/mol acetate · Complete oxidation to CO2.
05 · Ecology & biofilm
Ecology & biofilm
How it lives on an electrode, who it partners with, and where it is found in nature.
Biofilm
- Forms biofilm: yes
Biofilm conductivity
0.05 (0.005–5) S/m
Preferred electrode materials
- graphite felt
- carbon cloth
- carbon brush
- stainless steel mesh
Electron-exchange partners (3)
- gives e⁻ to →Methanothrix harundinacea
methanogenic anaerobic digester, rice paddy soil
Co culture demonstrated - gives e⁻ to →Methanosarcina acetivorans
methanogenic systems
Co culture demonstrated - ← takes e⁻ fromGeobacter metallireducens GS-15
ethanol→fumarate co-culture
Co culture demonstrated
Frequently co-occurs with
- Methanothrix harundinacea
- Methanosarcina spp.
- Pelobacter spp.
Conductive-mineral mediation
- Mediates via conductive minerals: yes
- Magnetite
- Biochar
Magnetite stimulates DIET with methanogen partners; biochar similarly enhances syntrophic acetate/butyrate degradation (Liu 2015, Cruz Viggi 2014).
Ecosystems
- Freshwater
- Subsurface
- Engineered MES
Isolation sources
- subsurface sediment, Norman, Oklahoma USA
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 (4)
- Bioremediation metals · Pilot scaleTRL 6/9
- Wastewater treatment · Pilot scaleTRL 5/9
- Bioelectricity generation · Bench scaleTRL 4/9
- Research model organism · Lab pure culture
Engineering
Reactor compatibility
- MFC dual chamber
- MEC
- Sediment MFC
- Scale demonstrated
- Pilot
Engineering history (3)
- 1994 Wild type isolation
Type strain isolated from Potomac River sediment.
1994 · Caccavo F, et al. 1994
- 2009 Evolution
Adaptive lab evolution under high-current selection (KN400 strain).
Max current density 4 → 7.6 A/m2
2009 · Yi H, et al. (2009). KN400 strain selection.DOI Spawned the geobacter_sulfurreducens_kn400 strain record (planned but not yet seeded).
- 2014 Engineered
Markerless deletion of omcZ; abolishes high-current biofilm phenotype.
2014 · Inoue K, et al. (2010); Liu Y, et al. (2014).DOI
Genetics
- Genetically tractable: yes
Key EET genes
- pilA
- omcB
- omcC
- omcS
- omcZ
- omcE
- ppcA
- imcH
- cbcL
qPCR targets
- pilA
- omcB
- omcZ
- omcS
Transformation methods
- Electroporation
- Available genetic tools
- markerless deletion
- pRG5 plasmid
- pCM66 derivatives
- CRISPR-Cas9
Omics studies (2)
Operation
- Fouling resistance
- High
- Load change sensitivity
- Low
- Recommended inoculation
- Pre-grown anode biofilm transfer or planktonic seed at OD600 0.05–0.1 with acetate poising.
- Pure vs mixed performance delta
- 1
Commercial
Strain itself is unencumbered; specific engineered variants may be IP-protected.
Biosafety
- Pathogen: no
Modeling assets
- Genome-scale metabolic model: yes
- Kinetic model: yes
- Biofilm model: yes
- iAF987 (Feist et al. 2014)
Linked GEM: iAF987
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
Literature reviewed 2026-04-26 · schema v1.2.0 · updated 2026-05-14 · imported 2026-04-28
Per-field confidence
- Engineering history
- High
- Genome metadata.size (bp)
- High
- Bibliometrics.total publications
- Medium
- EET mechanism.direct transfer.cytochromes
- High
- Electrochemical performance.max current density
- High
References (10)
- Caccavo F, et al. (1994). Geobacter sulfurreducens sp. nov. Appl Environ Microbiol 60:3752-3759.PMID 7527204
- Caccavo F, et al. (1994). Geobacter sulfurreducens sp. nov. Appl Environ Microbiol 60:3752-3759.PMID 7527204
- Bond DR, Lovley DR (2003). Electricity production by Geobacter sulfurreducens attached to electrodes. Appl Environ Microbiol 69:1548-1555.doi:10.1128/AEM.69.3.1548-1555.2003
- Bond DR, Lovley DR (2003). Electricity production by Geobacter sulfurreducens attached to electrodes. Appl Environ Microbiol 69:1548-1555.doi:10.1128/AEM.69.3.1548-1555.2003
- Reguera G, et al. (2005). Extracellular electron transfer via microbial nanowires. Nature 435:1098-1101.doi:10.1038/nature03661
- Reguera G, et al. (2005). Extracellular electron transfer via microbial nanowires. Nature 435:1098-1101.doi:10.1038/nature03661
- Logan BE, et al. (2019). Electroactive microorganisms in BES. Nat Rev Microbiol 17:307-319.doi:10.1038/s41579-019-0173-x
- Logan BE, et al. (2019). Electroactive microorganisms in BES. Nat Rev Microbiol 17:307-319.doi:10.1038/s41579-019-0173-x
- Wang F, et al. (2019). Structure of microbial nanowires reveals stacked hemes. Cell 177:361-369.
- Wang F, et al. (2019). Structure of microbial nanowires reveals stacked hemes. Cell 177:361-369.
Bibliometrics
| PI | Lab | Country |
|---|---|---|
| Derek R. Lovley | Lovley Lab | USA |
| Nikhil S. Malvankar | Malvankar Lab | USA |
| Notes | Topic | Conflicting DOIs |
|---|---|---|
| Reguera 2005 reported PilA pili as nanowires; Wang 2019 demonstrated OmcS cytochrome filaments. Current consensus: OmcS/OmcZ filaments are the primary nanowires; PilA pilin is a secretion machine. | Pilus vs cytochrome-filament identity of conductive nanowires | 10.1038/nature03661, 10.1016/j.cell.2019.03.029 |
| Year | Citation | DOI |
|---|---|---|
| 2012 | Lovley DR (2012). Electromicrobiology. Annu Rev Microbiol 66:391-409. | — |
| 2019 | Logan BE, et al. (2019). Electroactive microorganisms in BES. Nat Rev Microbiol 17:307-319. | 10.1038/s41579-019-0173-x |
Version history
- 2026-04-27 · v1.2.0 · messai_curation
- Added structured cytochromes[] inventory with localization, heme counts, midpoint potentials.
- Added genome_metadata, isolation provenance, type strain flag.
- Added engineering_history (KN400 ALE; omcZ knockout).
- Added bibliometrics, omics_resources, conductive mineral mediation.