Two-strain synthetic consortium of an engineered degrader (Pseudomonas putida strain Pp-TE) and a native degrader (Rhodococcus sp. strain RDK17) grown with terephthalic acid (TPA), a primary polyethylene terephthalate (PET) monomer, as the sole carbon and energy source. Although both strains utilize TPA at comparable rates in monoculture, Pp-TE consistently outcompetes RDK17 in batch and multitransfer coculture fermentations. Dominance is driven jointly by exploitative competition for TPA and by interference competition through the Pp-TE type VI secretion system, which impairs RDK17 growth via contact-dependent inhibition. Loss of TPA metabolism in Pp-TE abolishes its dominance, illustrating how interspecies interaction and metabolic capability co-determine consortium structure and overall TPA degradation.
Taxonomy
| Taxon | Ontology ID | Functional Roles | Abundance |
|---|---|---|---|
| Pseudomonas putida strain Pp-TE (engineered) — ontology label: Pseudomonas putida | NCBITaxon:303 · TaxonMech · TraitMech |
PRIMARY_DEGRADER
|
N/A |
|
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| Rhodococcus sp. strain RDK17 (native) — ontology label: Rhodococcus <high G+C Gram-positive bacteria> | NCBITaxon:1827 · TaxonMech · TraitMech |
PRIMARY_DEGRADER
|
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.
Exploitative competition for terephthalic acid
COMPETITIONBoth members use the shared substrate, and the source reports that abolishing its metabolism in Pp-TE removes dominance. This supports a metabolic contribution to competition; dominance alone does not identify that mechanism. PARTIAL: the abstract does not separately quantify resource competition and contact-inhibition contributions.
Source Taxon: Pseudomonas putida strain Pp-TE (engineered)
Target Taxon: Rhodococcus sp. strain RDK17 (native)
Metabolites: terephthalic acid (TPA) (CHEBI:15702 · MediaIngredientMech · CMMMech)
The source-reported metabolic perturbation supports a contribution of substrate use to dominance, alongside contact inhibition. PARTIAL: their separate effect sizes are not resolved by the accessible abstract.
Evidence
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PMID:42324694 - SUPPORT (IN_VITRO)"Pp-TE consistently outcompeted RDK17 in batch and multitransfer coculture fermentations, even when RDK17 was inoculated at a significantly higher initial abundance"
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PMID:42324694 - SUPPORT (IN_VITRO)"when TPA metabolism was abolished in Pp-TE, it lost its dominance to RDK17"
Interference competition via type VI secretion system
COMPETITIONThe authors report assays attributing the main competitive advantage to type-VI-secretion-associated contact inhibition, with a partial contribution from relative growth kinetics. Preserve this experimental attribution; the accessible abstract does not expose the full controls or separate effect sizes.
Source Taxon: Pseudomonas putida strain Pp-TE (engineered)
Target Taxon: Rhodococcus sp. strain RDK17 (native)
Biological Processes:
- protein secretion by the type VI secretion system (GO:0033103 · PathwayMech)
The source reports that contact-dependent impairment of the partner is the main contributor to dominance, alongside metabolic capability and relative kinetics. This preserves the reported causal attribution without independently certifying unreviewed methods.
Evidence
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PMID:42324694 - SUPPORT (IN_VITRO)"the dominance of Pp-TE was primarily conferred by its type VI secretion system, which impaired the growth of RDK17 via contact-dependent inhibition"
Pp-TE Dominance During TPA Coculture
COMPETITIONPp-TE consistently outcompetes RDK17 in the reported batch and serial-transfer cocultures. This is the measured population outcome; its mechanistic attribution is represented by the two upstream nodes, not inferred from dominance alone.
Source Taxon: Pseudomonas putida strain Pp-TE (engineered)
Target Taxon: Rhodococcus sp. strain RDK17 (native)
Metabolites: terephthalic acid (TPA) (CHEBI:15702 · MediaIngredientMech · CMMMech)
Biological Processes:
- biological process involved in interspecies interaction between organisms (GO:0044419 · PathwayMech)
Evidence
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PMID:42324694 - SUPPORT (IN_VITRO)"Pp-TE consistently outcompeted RDK17 in batch and multitransfer coculture fermentations"
Knowledge gaps & discussions (1)
KNOWLEDGE_GAP OPEN How are the two competitive contributions distinguished from the dominance observation?
All three competition nodes and both existing directions remain. The primary abstract reports contact inhibition, relative kinetics and a metabolism-loss comparison; those positive findings are retained. Full methods and quantitative decomposition were unavailable, which does not imply absent controls. No new resistance-selection details, genetic designs or experimental protocols were added.
Attaches to: ecological_interactions#Exploitative competition for terephthalic acid, ecological_interactions#Interference competition via type VI secretion system, ecological_interactions#Pp-TE Dominance During TPA Coculture
2 evidence item(s)
Pp-TE consistently outcompeted RDK17 in batch and multitransfer coculture fermentations, even when RDK17 was inoculated at a significantly higher initial abundance
Supports the observed competitive outcome, not by itself the mechanism of resource competition.
the dominance of Pp-TE was primarily conferred by its type VI secretion system, which impaired the growth of RDK17 via contact-dependent inhibition
Contact-dependent inhibition through the Pp-TE T6SS is interference competition against RDK17.
Growth Media
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