Rod

Electrogen · Bidirectional EET · Iron reducer

Shewanella oneidensis MR-1

Also known as Alteromonas putrefaciens MR-1

Pseudomonadota · Gammaproteobacteria · Shewanellaceae

ElectroactiveEET bidirectionalType strainBSL-1Comprehensive record

Model organism
Facultative
Metabolically versatile
Tier 1

Bidirectional

Electron transfer

electroactive

30°C

Optimal temperature

grows 4–35 °C

Optimal pH

grows pH 6–8

0.5A/m2

Max current density

range 0.2–3

01 · Identity

Identity

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

Lineage

domainBacteria
›phylumPseudomonadota
›classGammaproteobacteria
›orderAlteromonadales
›familyShewanellaceae
›genusShewanella
›speciesShewanella oneidensis MR-1

Culture collections & accessions

ATCC: ATCC 700550
NCBI taxon: 211586
Genome: GCF_000146165.2
Status: Type strain

Isolation

From Lake Oneida sediment, New York, USA by Myers CR, Nealson KH (1988).

Myers CR, Nealson KH (1988). Bacterial manganese reduction and growth with manganese oxide as the sole electron acceptor.

Genome

4.97Mb

Genome size

45.9%

GC content

Complete

Assembly level

Contigs

Name	Size (kb)	Accession	Replicon type
pMR-1	161.6 kb	AE014300.2	Megaplasmid

Cell morphology

Rod

Rod, Gram-negative (diderm)

length 2.5 (2–3) µm · width 0.5 (0.4–0.7) µm

Motile: yes
Pili: yes
S-layer: no
Outer-membrane vesicles: yes
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 bidirectional

Electrons flow both ways

Mechanisms

Outer-membrane cytochromes: yes
Conductive pili / nanowires: yes
Endogenous shuttles: yes
Exogenous shuttles: yes

Nanowire conductivity 0.001 (0.0001–0.01) S/cm

Outer-membrane extension nanowires; lower conductivity than Geobacter cytochrome filaments. See Pirbadian 2014.

Redox ladder

■ cytochrome · ○ shuttleE°′ (V vs SHE)

1FMN -0.219 V · endogenous
2riboflavin -0.208 V · endogenous
3CymA -0.19 V · Inner membrane · 4 hemes
4MtrA -0.14 V · Periplasm · 10 hemes
5OmcA -0.12 V · Outer membrane · 10 hemes
6MtrC -0.1 V · Outer membrane · 10 hemes

Cytochromes (6)

Name	Location	Hemes	E°′ (V)	Structure
CymA	Inner membrane	4	-0.19	— Quinone-pool-coupled tetraheme; entry point for MtrCAB pathway.
MtrA	Periplasm	10	-0.14	PDB 6R2Q Periplasmic decaheme of the MtrCAB porin-cytochrome complex.
MtrB	Outer membrane	—	—	PDB 6R2Q β-barrel porin component of MtrCAB; not a cytochrome itself but harbors MtrA.
MtrC	Outer membrane	10	-0.1	PDB 4LM8 Outer-membrane decaheme; primary electron transfer to electrode/Fe(III).
OmcA	Outer membrane	10	-0.12	PDB 4LMH Outer-membrane decaheme; binds Fe(III) and electrode surface.
STC	Periplasm	4	—	— Small tetraheme cytochrome; cytoplasmic-pool-to-MtrA shuttle.

Electron shuttles (2)

FMN · endogenous · E°′ -0.219 V · 0.05 µM/OD600
Co-secreted with riboflavin; functions analogously.
riboflavin · endogenous · E°′ -0.208 V · 0.13 µM/OD600
Released into the medium during growth; binds MtrC/OmcA to facilitate single-step electron transfer.

Direct transfer — detail

Completeness: Mapped

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.

MesophileFacultative anaerobeChemoorganoheterotroph

Temperature30 (4–35) °C

0100 °C

pH7 (6–8)

014

Doubling time1 (0.7–2) h

02.5 h

Energy metabolism

Electron donors

Lactate
Formate
H2

Electron acceptors

O2
Fe(III)
Mn(IV)
Nitrate
Fumarate
Dmso
Tmao
Anode
S2O3
U(VI)

Carbon sources

Lactate
Pyruvate
Formate
N-acetylglucosamine
amino acids

Respiratory: yes
Fermentative: no

Metabolism — detail

ATP synthase type: Proton dependent
Energy conservation mechanism: Oxidative phosphorylation

Growth kinetics

µmax0.182 (0.014–0.35) h^-1

00.5 h^-1

From 2 DB row(s) across 1 paper(s); source units: h^-1. Pooled across substrates: glucose, lactate — substrate-specific breakdown in per_substrate. Includes engineered/variant strings: Shewanella oneidensis MR-1(pBBR-glk-galP). Full provenance: services/ml-engine/data/kinetics-extracted/per-strain-aggregated.json.

Ks (substrate)124 mM

0200 mM

From 1 DB row(s) across 1 paper(s); source units: mg/L. Full provenance: services/ml-engine/data/kinetics-extracted/per-strain-aggregated.json.

Substrate	µ max	Observations
Glucose	0.014 h^-1	1
Lactate	0.35 h^-1	1

04 · Performance

Performance

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

Strong electrogen

250mW/m2

Max power density

range 100–850 · per projected anode area

0.5A/m2

Max current density

range 0.2–3 · per projected anode area

600mV

Open circuit voltage

range 400–750

25%

Coulombic efficiency

range 10–56

Role in a reactor

Anode chamberAnode: primary current producer

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 thickness15 (5–40) µm

050 µm

Preferred electrode materials

carbon cloth
graphite felt
ITO
Gold

Ecosystems

Freshwater
Sediment freshwater

Isolation sources

sediment, Lake Oneida, New York, 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)

Biosensor
TRL 5/9
Bioelectricity generation
TRL 4/9
Bioremediation metals
TRL 4/9
Research model organism

Engineering

Synthetic biology chassisIndustrial relevance 5/5

Reactor compatibility

MFC single chamber
MFC dual chamber
MEC

Engineering history (2)

1988 Wild type isolation
Type strain isolated as MR-1 (Manganese Reducer 1).
1988 · Myers CR, Nealson KH 1988DOI
2009 Engineered
ΔmtrC/ΔomcA double knockout — abolishes Fe(III)/anode reduction.
2010 · Bretschger O, et al. (2007); Coursolle D, et al. (2010).

Genetics

Genetically tractable: yes

Key EET genes

mtrA
mtrB
mtrC
mtrD
mtrE
mtrF
omcA
cymA

qPCR targets

mtrB
mtrC
omcA
cymA

Transformation methods

Electroporation
Conjugation

Vectors

pBBR1MCS-derived suicide vectors
pSMV3

CRISPR systems

CRISPRi-dCas9 (heterologous)

Reporter genes

GFP
lacZ

Inducible promoters

arabinose pBAD
rhamnose pRha

Transposon libraries

EZ-Tn5 in MR-1 (Bouhenni 2005)

Genome annotation: expert curated.

Omics studies (2)

Transcriptomics RNA seq aerobic vs anaerobic · 2012DOI
Proteomics Shotgun proteomics anode · 2013DOI

Biosafety

BSL-1

Pathogen: no

Modeling assets

Genome-scale metabolic model: yes
Kinetic model: yes

iSO783

Linked GEM: iSO783

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

ComprehensiveHigh confidenceCurated: manual

Literature reviewed 2026-04-26 · schema v1.2.0 · updated 2026-05-14 · imported 2026-04-28

Per-field confidence

Genome metadata.size (bp): High
EET mechanism.mediated transfer.shuttles: High
EET mechanism.direct transfer.cytochromes: High

References (6)

Myers CR, Nealson KH (1988). Bacterial manganese reduction. Science 240:1319-1321.
Myers CR, Nealson KH (1988). Bacterial manganese reduction. Science 240:1319-1321.
Marsili E, et al. (2008). Shewanella secretes flavins. PNAS 105:3968-3973.doi:10.1073/pnas.0710525105
Marsili E, et al. (2008). Shewanella secretes flavins. PNAS 105:3968-3973.doi:10.1073/pnas.0710525105
Pirbadian S, et al. (2014). Shewanella oneidensis nanowires are OM/periplasmic extensions. PNAS 111:12883-12888.doi:10.1073/pnas.1410551111
Pirbadian S, et al. (2014). Shewanella oneidensis nanowires are OM/periplasmic extensions. PNAS 111:12883-12888.doi:10.1073/pnas.1410551111

Version history

2026-04-27 · v1.2.0 · messai_curation
- Added MtrCAB cytochrome inventory with PDB IDs and midpoint potentials.
- Added structured riboflavin/FMN shuttles with redox potentials.
- Added genome_metadata with megaplasmid pMR-1.
- Added genetic_tools structured catalog.