Engineered two-member denitrifying consortium of the electroactive bacterium Shewanella oneidensis and the denitrifier Pseudomonas aeruginosa, operated in anaerobic conditions with metallic iron (Fe0) as the sole electron donor. S. oneidensis acts as a bio-engine, using its membrane-bound CymA-OmcA-MtrC complexes to harvest electrons from Fe0 biocorrosion and transfer them to P. aeruginosa. P. aeruginosa accepts these electrons for nitrate reduction, accomplishing microbial denitrification via a Fe0-S. oneidensis-P. aeruginosa electron-transfer system. This Fe0-dependent electro-syntrophy defines a metabolic window for denitrifier growth relevant to nitrate removal in water/wastewater treatment and the global nitrogen cycle.
Taxonomy
| Taxon | Ontology ID | Functional Roles | Abundance |
|---|---|---|---|
| Shewanella oneidensis | NCBITaxon:70863 · TaxonMech · TraitMech |
ELECTROGEN
ELECTRON_DONOR
SYNTROPHIC_PARTNER
|
N/A |
|
|||
| Pseudomonas aeruginosa | NCBITaxon:287 · TaxonMech · TraitMech |
ELECTROTROPH
ELECTRON_ACCEPTOR
SYNTROPHIC_PARTNER
|
N/A |
|
|||
Ecological Interactions
The graph shows only explicitly linked interaction participants. Community members without an asserted participant link are omitted; membership alone does not imply an interaction.
Shewanella Fe0-Biocorrosion Electron Harvesting
The primary abstract reports that Shewanella oneidensis harvests electrons and conserves energy from metallic-iron biocorrosion in the model consortium. This donor-side process is retained without assigning a separate syntrophic feedback interaction.
Participating Taxa: Shewanella oneidensis
Biological Processes:
- electron transport chain (GO:0022900 · PathwayMech)
Electron harvest from metallic iron supplies the electrons that the source reports passing from S. oneidensis to P. aeruginosa in the model consortium. This preserves the reported upstream-to-transfer direction without adding a reciprocal feedback claim.
Evidence
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PMID:39504696 - SUPPORT (IN_VITRO)"using Fe0 as the sole electron donor, S. oneidensis can act as a bio-engine to harvest electrons and conserve energy from Fe0 biocorrosion"
Fe0-Dependent Interspecies Electron Transfer
The source reports electron transfer from S. oneidensis to P. aeruginosa in the Fe0-dependent consortium, described by the authors as direct electron cross-feeding and electro-syntrophy. The reported metatranscriptomic response is not by itself proof that the associated expression changes are necessary for this route. The abstract does not independently establish the product-removal feedback required by the schema SYNTROPHY definition; direct electrons are not assigned a metabolite-exchange category.
Source Taxon: Shewanella oneidensis
Target Taxon: Pseudomonas aeruginosa
Metabolites: nitrate (CHEBI:17632 · MediaIngredientMech · CMMMech)
Biological Processes:
- denitrification (GO:0019333 · PathwayMech)
Electrons transferred from S. oneidensis to P. aeruginosa are accepted by the denitrifier to drive nitrate reduction.
Evidence
-
PMID:39504696 - SUPPORT (IN_VITRO)"Electrons released by S. oneidensis are utilized by P. aeruginosa for accomplishing microbial denitrification."
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PMID:39504696 - SUPPORT (IN_VITRO)"the direct electron cross-feeding process facilitates the expression of genes encoding for denitrification enzymes, intracellular electron transfer proteins, and quorum sensing of P. aeruginosa"
Pseudomonas Nitrate Reduction by Accepted Electrons
Pseudomonas aeruginosa is reported to use electrons from the Fe0-Shewanella transfer system for nitrate reduction in the model consortium. This recipient-side outcome is retained without treating it as a separate syntrophic interaction or as evidence of a feedback benefit to the donor.
Participating Taxa: Pseudomonas aeruginosa
Metabolites: nitrate (CHEBI:17632 · MediaIngredientMech · CMMMech)
Biological Processes:
- denitrification (GO:0019333 · PathwayMech)
Evidence
-
PMID:39504696 - SUPPORT (IN_VITRO)"P. aeruginosa can accept electrons for nitrate reduction via the constructed electron transfer system of Fe0-S. oneidensis-P. aeruginosa"
Knowledge gaps & discussions (1)
KNOWLEDGE_GAP OPEN Does the reported electron-transfer route establish donor-side product-removal feedback?
The fresh primary abstract and whole committed abstract cache support the electron-transfer direction and nitrate-reduction outcome. Complete main text and the underlying controls were not independently reviewed. The authors' electro-syntrophy terminology does not by itself establish the schema-specific feedback that makes the donor metabolism favorable; expression responses also do not isolate causal necessity. These are evidence-attribution limits, not evidence that the reported route is absent.
Attaches to: ecological_interactions#Shewanella Fe0-Biocorrosion Electron Harvesting, ecological_interactions#Fe0-Dependent Interspecies Electron Transfer, ecological_interactions#Pseudomonas Nitrate Reduction by Accepted Electrons
1 evidence item(s)
Electrons released by S. oneidensis are utilized by P. aeruginosa for accomplishing microbial denitrification.
Supports the source-reported donor-to-recipient electron-transfer direction, not an independently verified reciprocal feedback.
Growth Media
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