A defined electroactive syntrophic coculture pairing Geobacter sulfurreducens with Pseudomonas aeruginosa in a restricted formate-fumarate medium. The community was used to study interspecies electron transfer and adaptive shifts from syntrophy toward competition. Early coculture growth depends on cooperative metabolism and direct interspecies electron transfer associated with Geobacter cytochromes, while adapted cocultures show increased Geobacter dominance and hydrogen/formate-linked electron-transfer features. The system is relevant to DOE biogeochemistry and bioelectrochemical applications because Geobacter-Pseudomonas interactions connect extracellular electron transfer, metal cycling, and microbial community modeling.
Taxonomy
| Taxon | Ontology ID | Functional Roles | Abundance |
|---|---|---|---|
| Geobacter sulfurreducens | NCBITaxon:35554 |
SYNTROPHIC_PARTNER
CROSS_FEEDER
|
DOMINANT |
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| Pseudomonas aeruginosa | NCBITaxon:287 |
SYNTROPHIC_PARTNER
CROSS_FEEDER
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COMMON |
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Ecological Interactions
Restricted-Medium Cooperative Growth
SYNTROPHYSource Taxon: Pseudomonas aeruginosa
Target Taxon: Geobacter sulfurreducens
Metabolites: formate (CHEBI:15740), fumarate (CHEBI:29806)
Biological Processes:
- electron transfer activity (GO:0009055)
Evidence
-
PMID:28992596 - SUPPORT (IN_VITRO)"preferential utilization of formate and fumarate by P. aeruginosa and G. sulfurreducens respectively"
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PMID:28992596 - SUPPORT (IN_VITRO)"Pure cultures did not yield significant growth while substantial growth was observed in cocultures"
Direct Interspecies Electron Transfer Establishment
SYNTROPHYSource Taxon: Geobacter sulfurreducens
Target Taxon: Pseudomonas aeruginosa
Metabolites: formate (CHEBI:15740), fumarate (CHEBI:29806)
Biological Processes:
- electron transfer activity (GO:0009055)
Evidence
-
PMID:28992596 - SUPPORT (COMPUTATIONAL)"upregulation in DIET-associated cytochromes"
-
PMID:28992596 - SUPPORT (COMPUTATIONAL)"DIET plays a critical role in the establishment of syntrophy"
Adaptation Toward Geobacter-Dominated Competition
COMPETITIONSource Taxon: Geobacter sulfurreducens
Target Taxon: Pseudomonas aeruginosa
Metabolites: phenazine-1-carboxylic acid (CHEBI:62412)
Biological Processes:
- electron transfer activity (GO:0009055)
Evidence
-
PMID:32265334 - SUPPORT (IN_VITRO)"transition from syntrophy to competition"
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PMID:32265334 - SUPPORT (COMPUTATIONAL)"fabI and tetR genes emerged that were strongly selected for throughout coculture evolution"
Phenazine-Associated Inhibition Pressure
COMPETITIONSource Taxon: Pseudomonas aeruginosa
Target Taxon: Geobacter sulfurreducens
Metabolites: phenazine-1-carboxylic acid (CHEBI:62412)
Biological Processes:
- electron transfer activity (GO:0009055)
Evidence
-
PMID:32265334 - SUPPORT (IN_VITRO)"Pseudomonas-derived phenazine-1-carboxylic acid (PHZ-1-CA) for its potential to inhibit Geobacter growth"
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PMID:32265334 - SUPPORT (IN_VITRO)"Despite its inhibitory properties, PHZ-1-CA did not drive variant selection"
External Resources
| Name | Repository | Resource ID |
|---|---|---|
|
Exact-system proteomics publication - Geobacter/Pseudomonas electroactive coculture
Primary SWATH-MS proteomics study establishing and evolving Geobacter sulfurreducens and Pseudomonas aeruginosa syntrophic cocultures. |
OTHER | PMID:28992596 |
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Exact-system adaptive-evolution publication - Geobacter/Pseudomonas coculture
Open-access adaptive-evolution study of G. sulfurreducens with P. aeruginosa. |
OTHER | PMID:32265334 |
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Environmental Factors
| Factor | Value | Unit |
|---|---|---|
| Restricted formate-fumarate medium | formate and fumarate | N/A |
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| Serial-transfer adaptation | adaptive evolution | N/A |
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