Home ← Back to Communities Text Map Taxonomic UMAP Sequence Map Network Schema All Mech projects

E. coli K-12 MG1655 Arg-Met Cross-Feeding Coculture

Community ID CommunityMech:000455
Ecological State ENGINEERED
Environment aerobic E. coli K-12 MG1655 amino-acid cross-feeding culture — ontology label: laboratory environment
ENVO:01001405 · HabitatMech ↗

A defined two-member synthetic Escherichia coli K-12 MG1655 coculture built from complementary double-mutant amino-acid auxotrophs. The ΔargA-ΔmetJ mutant requires arginine and overproduces methionine, while the ΔmetA-ΔargR mutant requires methionine and overproduces arginine, producing an obligate Arg/Met mutualism that the study used to test how metabolic cross-feeding changes single-cell fluorescence noise under liquid, strain-ratio, and spatial heterogeneity perturbations.

Taxonomy

Taxon Ontology ID Functional Roles Abundance
Escherichia coli K-12 MG1655 ΔargA-ΔmetJ — ontology label: Escherichia coli str. K-12 substr. MG1655 NCBITaxon:511145 · TaxonMech · TraitMech
CROSS_FEEDER
N/A
  • PMID:42592155 - SUPPORT (IN_VITRO)
    "ΔargA-ΔmetJ required arginine (Arg) to grow but overproduced methionine (Met)"
Escherichia coli K-12 MG1655 ΔmetA-ΔargR — ontology label: Escherichia coli str. K-12 substr. MG1655 NCBITaxon:511145 · TaxonMech · TraitMech
CROSS_FEEDER
N/A
  • PMID:42592155 - SUPPORT (IN_VITRO)
    "ΔmetA-ΔargR needed Met but overproduced Arg"

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.

Ecological interaction network for E. coli K-12 MG1655 Arg-Met Cross-Feeding Coculture Bipartite graph where circles represent taxa and non-circular symbols represent interactions, with distinct shapes and colours for cross-feeding, mutualism.
Taxon
Cross-feeding
Mutualism

ΔargA-ΔmetJ methionine cross-feeding

CROSS_FEEDING

The delta-argA/delta-metJ mutant overproduces methionine supporting the methionine-requiring delta-metA/delta-argR partner under the tested amino-acid limitation. Both strains are E. coli K-12 MG1655 derivatives. Reciprocal growth dependence does not resolve the release route or single-cell export flux, and supplemented cultures need not remain obligately mutualistic.

Source Taxon: Escherichia coli K-12 MG1655 ΔargA-ΔmetJ

Target Taxon: Escherichia coli K-12 MG1655 ΔmetA-ΔargR

Metabolites: methionine (CHEBI:16811 · MediaIngredientMech · CMMMech)

Biological Processes:

Evidence

  • PMID:42592155 - SUPPORT (IN_VITRO)
    "ΔargA-ΔmetJ required arginine (Arg) to grow but overproduced methionine (Met)"
  • PMID:42592155 - SUPPORT (IN_VITRO)
    "cooperated by exchanging two essential AAs (Met and Arg)"

ΔmetA-ΔargR arginine cross-feeding

CROSS_FEEDING

The delta-metA/delta-argR mutant supplies arginine supporting the arginine-requiring delta-argA/delta-metJ partner under the tested amino-acid limitation. The same canonical taxon ID represents distinct engineered genotypes, not one organism acting on itself. Supplementation can remove partner dependence; this is not universal obligate exchange across media.

Source Taxon: Escherichia coli K-12 MG1655 ΔmetA-ΔargR

Target Taxon: Escherichia coli K-12 MG1655 ΔargA-ΔmetJ

Metabolites: arginine (CHEBI:29016 · MediaIngredientMech · CMMMech)

Biological Processes:

Evidence

  • PMID:42592155 - SUPPORT (IN_VITRO)
    "ΔmetA-ΔargR needed Met but overproduced Arg"
  • PMID:42592155 - SUPPORT (IN_VITRO)
    "cooperated by exchanging two essential AAs (Met and Arg)"

Arg-Met obligate mutualism increases cell noise

MUTUALISM

In the tested nutrient-limited Arg/Met coculture, reciprocal exchange was associated with higher single-cell fluorescent-reporter coefficient of variation than in supplemented monocultures. Mean amino-acid matching controls supported a heterogeneity interpretation. Reporter amino-acid sensitivity and experimental context matter: this is not a direct measurement of intrinsic transcriptional noise, a universal protein-noise effect or evidence that noise causes community collapse. MUTUALISM denotes the restricted reciprocal-growth model, not every supplementation condition.

Participating Taxa: Escherichia coli K-12 MG1655 ΔargA-ΔmetJ, Escherichia coli K-12 MG1655 ΔmetA-ΔargR

Metabolites: methionine (CHEBI:16811 · MediaIngredientMech · CMMMech), arginine (CHEBI:29016 · MediaIngredientMech · CMMMech)

Evidence

  • PMID:42592155 - SUPPORT (IN_VITRO)
    "forming an obligate mutualistic relationship through exchanging essential AAs with each other"
  • PMID:42592155 - SUPPORT (IN_VITRO)
    "cross-feeding consistently increased cell noise of two populations"

Knowledge gaps & discussions (3)

KNOWLEDGE_GAP OPEN What exact M9-glucose recipe, antibiotic and IPTG concentrations, amino-acid omission/addition conditions, inoculum density, and culture volumes were used for each Arg/Met co-culture experiment?

The primary full text supports LB or M9-glucose aerobic culture at 37 C and 200 rpm and says that detailed information for Experiments 1-8 was presented in Supplementary data, so condition-specific recipes should be resolved from the supplement before asserting exact amino-acid supplementation or inoculum sizes.

Attaches to: growth_media#LB or M9-glucose E. coli aerobic culture media, cultivation_setup

KNOWLEDGE_GAP OPEN Should the ΔargA-ΔtrpR/ΔtrpC-ΔargR pair and BL21-GFP environmental-isolate co-cultures be curated as separate variant records?

The main text reports a second K-12 MG1655 auxotrophic pair and synthetic environmental communities, but this record intentionally covers the primary ΔargA-ΔmetJ/ΔmetA-ΔargR arginine-methionine system rather than grouping all variant co-cultures under one biological identity.

KNOWLEDGE_GAP OPEN How do nutrient heterogeneity and reporter sensitivity mediate the Arg/Met fluorescence response?

Existing nodes are qualified, not an exhaustive mechanism graph. The primary main body supports assessing additional structure for reporter sensitivity and manipulated nutrient, strain-ratio and spatial heterogeneity. Mixed preincubations are not a direct spatial nutrient map, and modeled diffusion/uptake is not measured micro-scale flux. Intrinsic/extrinsic noise remains unresolved. Keep distinct Arg-Trp and BL21/environmental-isolate experiments outside this record. One-community Edison dry run is complete, but no provider job was submitted; expansion remains needs_research under #1436 pending specific spend authorization. Preserve the existing supplement/protocol and alternative-pair gaps.

Attaches to: ecological_interactions#ΔargA-ΔmetJ methionine cross-feeding, ecological_interactions#ΔmetA-ΔargR arginine cross-feeding, ecological_interactions#Arg-Met obligate mutualism increases cell noise

External Resources

Name Repository Resource ID
PubMed - E. coli K-12 Arg-Met cross-feeding coculture
PubMed record for the National Science Review article describing engineered E. coli amino-acid cross-feeding and emergent phenotypic heterogeneity. 		OTHER PMID:42592155
DOI - E. coli K-12 Arg-Met cross-feeding coculture
DOI landing page for the primary National Science Review article on synthetic cross-feeding consortia. 		OTHER doi:10.1093/nsr/nwag357
PubMed Central - E. coli K-12 Arg-Met cross-feeding coculture
Open full text for the primary article. 		OTHER PMCID:PMC13463769

Environmental Factors

Factor Value Unit
Arginine and methionine reciprocal auxotrophy ΔargA-ΔmetJ requires Arg and overproduces Met; ΔmetA-ΔargR requires Met and overproduces Arg N/A
  • PMID:42592155 - SUPPORT (IN_VITRO)
    "ΔargA-ΔmetJ required arginine (Arg) to grow but overproduced methionine (Met), while ΔmetA-ΔargR needed Met but overproduced Arg"
Strain-ratio heterogeneity ΔargA-ΔmetJ:ΔmetA-ΔargR pre-culture ratios varied from 1:2/2:1 to 1:8/8:1 N/A
  • PMID:42592155 - SUPPORT (IN_VITRO)
    "co-cultured ΔargA-ΔmetJ and ΔmetA-ΔargR under three different levels of heterogeneity in strain distribution"
Spatial structure shaken liquid, pre-mixed agar, and adjacent unmixed agar co-cultures N/A
  • PMID:42592155 - SUPPORT (IN_VITRO)
    "co-cultured in liquid cultures with shaking (low), in agar plates with two populations well pre-mixed (medium) or placed adjacently without pre-mixing (high)"

Growth Media

LB or M9-glucose E. coli aerobic culture media

Temperature 37 °C
Atmosphere AEROBIC

Composition

Component Concentration Unit CHEBI
glucose · MediaIngredientMech N/A N/A N/A

Preparation notes: The full article states that E. coli strains were grown aerobically in LB or M9-glucose at 37 C and 200 rpm, with antibiotics, IPTG, and amino acids added as required; the primary full text points to Supplementary data for more detailed experiment-by-experiment recipes.

Evidence

PMID:42592155

"E. coli strains were cultured aerobically in LB (Luria-Bertani broth) or M9-glucose media (M9 media)"

PMID:42592155

"at 37°C, 200 rpm"

PMID:42592155

"Antibiotics, IPTG (Isopropyl β-D-1-thiogalactopyranoside) and AAs were added as required"

Cross-Mech Suite Links

Explore related entities across the CultureBotAI X-Mech knowledge bases:

HabitatMech: aerobic E. coli K-12 MG1655 amino-acid cross-feeding culture ↗ TaxonMech: Escherichia coli K-12 MG1655 ΔargA-ΔmetJ ↗ TraitMech: Escherichia coli K-12 MG1655 ΔargA-ΔmetJ ↗ TaxonMech: Escherichia coli K-12 MG1655 ΔmetA-ΔargR ↗ TraitMech: Escherichia coli K-12 MG1655 ΔmetA-ΔargR ↗ CultureMech Growth Media ↗ PathwayMech Pathways ↗