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SynCom ARC Peanut Aflatoxin-Control and Nodulation-Coupling Community

Community ID CommunityMech:000314
Ecological State ENGINEERED
Environment peanut rhizosphere — ontology label: rhizosphere
ENVO:00005801 · HabitatMech ↗

A four-strain rhizosphere synthetic community — three Bacillus isolates (Bl13-2C11, Ba13-20E05, Bm14-5G09) and one Enterobacter isolate (El17-4B09) — assembled to couple two functions that are normally pursued separately in peanut: suppression of the aflatoxin-producing fungus Aspergillus flavus, and induction of rhizobia-legume nodulation. Candidate genera were chosen from cross-regional rhizosphere surveys as taxa negatively correlated with Aspergillus abundance but not with Bradyrhizobium, so that antifungal activity would not come at the cost of the nitrogen- fixing symbiont; strains that inhibited Bradyrhizobium in coculture were screened out on exactly that criterion. The resulting community, SynCom ARC, reduced peanut aflatoxin by 85.6% across four years of field trials and enhanced nodulation and nitrogenase activity while retaining active nodules at harvest. The record captures the community as a deliberately compatibility- constrained consortium: its design problem is not maximal antifungal potency but antagonism of the pathogen that spares a mutualist.

Taxonomy

Taxon Ontology ID Functional Roles Abundance
Bacillus (ARC strains Bl13-2C11, Ba13-20E05, Bm14-5G09) — ontology label: Bacillus <firmicutes> NCBITaxon:1386 · TaxonMech · TraitMech N/A
  • PMID:42099455 - SUPPORT (IN_VITRO)
    "3 Bacillus (Bl13‐2C11, Ba13‐20E05, Bm14‐5G09) and 1 Enterobacter (El17‐4B09) were selected for further study"
Enterobacter (ARC strain El17-4B09) — ontology label: Enterobacter NCBITaxon:547 · TaxonMech · TraitMech N/A
  • PMID:42099455 - SUPPORT (IN_VITRO)
    "nine strains demonstrated an aflatoxin inhibition rate exceeding 95%: 7 Bacillus, 2 Enterobacter"
Bradyrhizobium PHNZY-24-6 — ontology label: Bradyrhizobium NCBITaxon:374 · TaxonMech · TraitMech
NITROGEN_FIXING_SYMBIONT
N/A
  • PMID:42099455 - SUPPORT (IN_VITRO)
    "3 Bacillus inhibited Bradyrhizobium"
Aspergillus flavus NCBITaxon:5059 · TaxonMech · TraitMech N/A
  • PMID:42099455 - SUPPORT (IN_VIVO)
    "SynCom ARC inhibits A. flavus growth and reduces peanut aflatoxin levels by 85.6% in 4 year field trials"
peanut — ontology label: Arachis hypogaea NCBITaxon:3818 · TaxonMech · TraitMech N/A
  • PMID:42099455 - SUPPORT (IN_VIVO)
    "SynCom ARC enhances peanut nodulation and nitrogenase activity"

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 SynCom ARC Peanut Aflatoxin-Control and Nodulation-Coupling Community Bipartite graph where circles represent taxa and non-circular symbols represent interactions, with distinct shapes and colours for colonization facilitation. Rare or untyped interactions share the Other symbol; exact curated types remain in the interaction details.
Taxon
Colonization facilitation
Other

SynCom ARC Suppression of Aspergillus flavus

The four-member ARC community inhibited A. flavus in the reported assays. In multi-year field comparisons, harvested peanuts showed lower aflatoxigenic fungal abundance, and the reported mean 85.6% aflatoxin reduction was measured after 12 months of natural storage. These protective outcomes do not demonstrate reciprocal-negative competition or resolve the individual inhibitory compounds.

Participating Taxa: Bacillus (ARC strains Bl13-2C11, Ba13-20E05, Bm14-5G09), Enterobacter (ARC strain El17-4B09), Aspergillus flavus, peanut

Biological Processes:

Downstream Effects:
→ Concurrent aflatoxin reduction, nodulation and yield outcomes

HYPOTHESIZED/PARTIAL: fungal suppression contributes to the aflatoxin-control component of the combined protective phenotype. Its contribution to the joint nodulation and yield outcome is not isolated from the other effects of ARC.

Evidence

  • PMID:42099455 - SUPPORT (IN_VIVO)
    "SynCom ARC inhibits A. flavus growth and reduces peanut aflatoxin levels by 85.6% in 4 year field trials"
  • PMID:42099455 - SUPPORT (IN_VIVO)
    "After 12 months of natural storage, aflatoxin levels were reduced by an average of 85.6%"

SynCom ARC Induction of Rhizobia-Legume Nodulation

COLONIZATION_FACILITATION

ARC enhanced peanut nodulation, nitrogenase activity and retention of active nodules. The laboratory comparison found no nodulation with ARC alone but more nodules when ARC accompanied rhizobia, supporting facilitation of the rhizobial-host association rather than nitrogen fixation by the four ARC members themselves. The source also reports increased rhizobial abundance; strain-specific persistence and the responsible compounds are not resolved.

Participating Taxa: Bacillus (ARC strains Bl13-2C11, Ba13-20E05, Bm14-5G09), Enterobacter (ARC strain El17-4B09), Bradyrhizobium PHNZY-24-6, peanut

Biological Processes:

Downstream Effects:
→ Concurrent aflatoxin reduction, nodulation and yield outcomes

HYPOTHESIZED/PARTIAL: enhanced rhizobial nodulation and nitrogenase activity are proposed to support the higher-yield phenotype alongside improved photosynthesis and carbon allocation. Parallel endpoints and omics associations do not isolate the contribution of nitrogen fixation or prove the proposed feedback quantitatively.

Evidence

  • PMID:42099455 - SUPPORT (IN_VIVO)
    "SynCom ARC enhances peanut nodulation and nitrogenase activity, retains active nodules at harvest"
  • PMID:42099455 - SUPPORT (IN_VIVO)
    "Laboratory tests showed ARC alone did not induce nodulation but promoted significantly more nodules when co-inoculated with rhizobia"

Concurrent aflatoxin reduction, nodulation and yield outcomes

ARC-treated field systems combined reduced aflatoxin, greater nodulation and nitrogenase activity, retained active nodules, improved photosynthetic measures and higher yield. These positive outcomes support the reported multifunctional phenotype. The proposed carbon-nitrogen feedback and precise contributions of fungal inhibition versus rhizobial facilitation remain preliminary mechanisms, not an independently demonstrated feedback loop or host antifungal immune response.

Biological Processes:

Evidence

  • PMID:42099455 - PARTIAL (IN_VIVO)
    "SynCom ARC inhibits multiple targets in A. flavus, recruits and activates nodulation and nitrogen fixation in rhizobia and peanut, and improves photosynthesis and carbon supply for aflatoxin prevention and nodulation induction, balancing yield increase"
  • PMID:42099455 - SUPPORT (IN_VIVO)
    "Building upon the phenotypic effects and preliminary mechanisms revealed in this study"

Knowledge gaps & discussions (1)

KNOWLEDGE_GAP OPEN Which mechanisms quantitatively connect ARC suppression and rhizobial facilitation to the combined field phenotype?

The positive suppression, nodulation and yield findings remain. The study describes preliminary mechanisms and leaves specific compounds and host regulation unresolved. Retain qualified contributions rather than a demonstrated feedback or host-defense mechanism. Counter-selected candidates remain outside the interaction graph; no toxin-production methods or optimization instructions are added.

Attaches to: ecological_interactions#SynCom ARC Suppression of Aspergillus flavus, ecological_interactions#SynCom ARC Induction of Rhizobia-Legume Nodulation, ecological_interactions#Concurrent aflatoxin reduction, nodulation and yield outcomes

1 evidence item(s)
IN_VIVO SUPPORT PMID:42099455

Building upon the phenotypic effects and preliminary mechanisms revealed in this study

The source distinguishes phenotypic effects from preliminary mechanistic interpretation.

Environmental Factors

Factor Value Unit
Multi-year multi-site field trial 4 years; 325 sites across 19 provinces N/A
  • PMID:42099455 - SUPPORT (IN_VIVO)
    "boosts yield without super nodulation penalty in 325 sites of 19 provinces"

Growth Media

peanut medium, for the ARC/A. flavus co-culture

Temperature 28 °C
Atmosphere AEROBIC

Composition

Component Concentration Unit CHEBI
potato infusion · MediaIngredientMech 200 g/L N/A
dextrose · MediaIngredientMech 20 g/L CHEBI:17234
peanut flour · MediaIngredientMech 1.5 g/L N/A

Preparation notes: Autoclaved 20 min at 121 C. This is the medium in which the SynCom meets its target: A. flavus at 5x10^5 spores/mL and the bacterial strain at 1x10^7 CFU/mL, with an A. flavus-only control. Quoted from the SUPPLEMENTARY methods, which is where this paper puts them -- the article body says only 'Co-cultured with A. flavus in liquid medium'. That text is appended to the reference cache under its own marker so the quote validates (#653).

Evidence

PMID:42099455

"And then A. flavus was mixed with the bacteria strain in a 100-mL flask containing 15 mL of peanut medium (potato 200 g/L, dextrose 20 g/L, and peanut flour 1.5 g/L; autoclaved for 20 min at 121"

PMID:42099455

"The final concentrations of A. flavus was 5×105 spores/mL and that of the bacterial strain was 1×107 colony-forming units (CFU)/mL."

PMID:42099455

"The mixtures were incubated with constant shaking (200 rpm) for 4 d."

LB medium, for the ARC bacterial strains

Temperature 28 °C
Atmosphere AEROBIC

Preparation notes: Grown to provide the bacterial partner, then counted by plate count. Pure isolates were separately held in LB broth at 28 C and 180 rpm to logarithmic phase before glycerol storage -- a different speed, kept in prose rather than overwriting the co-culture figure. Quoted from the SUPPLEMENTARY methods, which is where this paper puts them -- the article body says only 'Co-cultured with A. flavus in liquid medium'. That text is appended to the reference cache under its own marker so the quote validates (#653).

Evidence

PMID:42099455

"Bacteria strain was grown in LB medium for 24 h at 28 ˚C with shaking at 200 rpm."

PMID:42099455

"Pure isolates were cultured in LB broth at 28°C with shaking at 180 rpm to the logarithmic phase, mixed 1:1 with 50% sterile glycerol, and stored at "

TY medium, for Bradyrhizobium

pH 7.0
Temperature 28 °C
Atmosphere AEROBIC

Composition

Component Concentration Unit CHEBI
tryptone · MediaIngredientMech 5 g/L N/A
yeast extract · MediaIngredientMech 3 g/L N/A
calcium chloride · MediaIngredientMech 10 mM CHEBI:3312

Preparation notes: The rhizobial partner is grown apart from the SynCom and from A. flavus; its own medium because no vessel held all three. Quoted from the SUPPLEMENTARY methods, which is where this paper puts them -- the article body says only 'Co-cultured with A. flavus in liquid medium'. That text is appended to the reference cache under its own marker so the quote validates (#653).

Evidence

PMID:42099455

"The Bradyrhizobium strain was grown in TY medium (5 g/L tryptone, 3 g/L yeast extract, 10 mM CaCl2, pH 7.0) at 28"

Cross-Mech Suite Links

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

HabitatMech: peanut rhizosphere ↗ TaxonMech: Bacillus (ARC strains Bl13-2C11, Ba13-20E05, Bm14-5G09) ↗ TraitMech: Bacillus (ARC strains Bl13-2C11, Ba13-20E05, Bm14-5G09) ↗ TaxonMech: Enterobacter (ARC strain El17-4B09) ↗ TraitMech: Enterobacter (ARC strain El17-4B09) ↗ TaxonMech: Bradyrhizobium PHNZY-24-6 ↗ TraitMech: Bradyrhizobium PHNZY-24-6 ↗ TaxonMech: Aspergillus flavus ↗ TraitMech: Aspergillus flavus ↗ TaxonMech: peanut ↗ TraitMech: peanut ↗ CultureMech Growth Media ↗ PathwayMech Pathways ↗