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Syntrophus Benzoate Degrader

Community ID CommunityMech:000071
Ecological State STABLE
Environment anaerobic sediments — ontology label: sediment
ENVO:00002007 · HabitatMech ↗

A two-member anaerobic syntrophic coculture consisting of Syntrophus aciditrophicus SB, which metabolizes benzoate and alicyclic intermediates in coculture with hydrogen-using partners, and Methanospirillum hungatei, a hydrogenotrophic methanogen. S. aciditrophicus-M. hungatei cocultures convert benzoate to acetate and methane while keeping hydrogen low enough for syntrophic benzoate degradation to proceed under methanogenic, strictly anaerobic conditions.

Taxonomy

Taxon Ontology ID Functional Roles Abundance
Syntrophus aciditrophicus SB NCBITaxon:56780 · TaxonMech · TraitMech
PRIMARY_DEGRADER SYNTROPHIC_PARTNER
N/A
  • doi:10.1128/aem.67.4.1728-1738.2001 - SUPPORT (IN_VITRO)
    "The metabolism of benzoate, cyclohex-1-ene carboxylate, and cyclohexane carboxylate by “ Syntrophus aciditrophicus ” in cocultures with hydrogen-using microorganisms was studied."
Methanospirillum hungatei NCBITaxon:2203 · TaxonMech · TraitMech
SYNTROPHIC_PARTNER
N/A
  • doi:10.1128/aem.67.4.1728-1738.2001 - SUPPORT (IN_VITRO)
    "Time course experiments relating methane production to benzoate consumption in “ S. aciditrophicus ”- M. hungatei cocultures indicated that the amount of methane produced per mole of benzoate consumed was much less than theoretically predicted (0.75 mol of methane per mol of benzoate) during the initial stages of benzoate metabolism."

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 Syntrophus Benzoate Degrader Bipartite graph where circles represent taxa and non-circular symbols represent interactions, with distinct shapes and colours for syntrophy. Rare or untyped interactions share the Other symbol; exact curated types remain in the interaction details.
Taxon
Syntrophy
Other

Syntrophus Benzoate Metabolism

SYNTROPHY

S. aciditrophicus strain SB metabolizes benzoate in the M. hungatei coculture, with transient alicyclic and dicarboxylate intermediates. This is the syntrophic route; the separate pure-culture experiment also demonstrates benzoate fermentation with a different product balance. Enzyme activities measured with Desulfovibrio or crotonate-grown pure cultures are not attributed as exact-pair assays here.

Source Taxon: Syntrophus aciditrophicus SB

Target Taxon: Methanospirillum hungatei

Metabolites: benzoate (CHEBI:16150 · MediaIngredientMech · CMMMech), acetate (CHEBI:30089 · MediaIngredientMech · CMMMech), dihydrogen (CHEBI:18276 · MediaIngredientMech · CMMMech), carbon dioxide (CHEBI:16526 · MediaIngredientMech · CMMMech)

Biological Processes:

Downstream Effects:
→ Community Benzoate Conversion to Acetate and Methane

Bacterial benzoate metabolism supplies reducing equivalents for the methanogenic partner and generates acetate, enabling the coupled coculture conversion rather than complete carbon mineralization.

Evidence

Interspecies Hydrogen Transfer and Methanogenesis

SYNTROPHY

M. hungatei is the hydrogen-using methanogen in the benzoate coculture. Hydrogen consumption provides an electron sink for the syntrophic conversion to acetate and methane. This does not mean benzoate metabolism is impossible without a partner: S. aciditrophicus pure cultures ferment benzoate with cyclohexane carboxylate accumulation and a different acetate yield.

Source Taxon: Methanospirillum hungatei

Target Taxon: Syntrophus aciditrophicus SB

Metabolites: dihydrogen (CHEBI:18276 · MediaIngredientMech · CMMMech), carbon dioxide (CHEBI:16526 · MediaIngredientMech · CMMMech), methane (CHEBI:16183 · MediaIngredientMech · CMMMech)

Biological Processes:

Downstream Effects:
→ Community Benzoate Conversion to Acetate and Methane

Methanogenic hydrogen consumption supplies the electron sink that couples benzoate oxidation to methane production and the coculture product balance; a different benzoate fermentation remains possible without this partner.

Evidence

  • "a coculture of S. aciditrophicus with the hydrogen-using methanogen Methanospirillum hungatei produced 3 mol of acetate and 0.75 mol of methane per mol of benzoate."
  • "The anaerobic bacterium Syntrophus aciditrophicus metabolized benzoate in pure culture in the absence of hydrogen-utilizing partners or terminal electron acceptors."

Community Benzoate Conversion to Acetate and Methane

The two-member benzoate coculture produced approximately three mol acetate and 0.75 mol methane per mol benzoate, as summarized in the primary abstract. This is substrate conversion, not complete mineralization: acetate remains organic carbon. The reported pure-culture product balance differs, including cyclohexane carboxylate accumulation.

Participating Taxa: Syntrophus aciditrophicus SB, Methanospirillum hungatei

Metabolites: benzoate (CHEBI:16150 · MediaIngredientMech · CMMMech), acetate (CHEBI:30089 · MediaIngredientMech · CMMMech), methane (CHEBI:16183 · MediaIngredientMech · CMMMech)

Biological Processes:

Evidence

  • "a coculture of S. aciditrophicus with the hydrogen-using methanogen Methanospirillum hungatei produced 3 mol of acetate and 0.75 mol of methane per mol of benzoate."
  • "The pure culture of S. aciditrophicus produced approximately 0.5 mol of cyclohexane carboxylate and 1.5 mol of acetate per mol of benzoate"

Environmental Factors

Factor Value Unit
Anaerobic Conditions Strict anaerobic N/A
Hydrogen Partial Pressure Must be maintained at low levels N/A
  • doi:10.1128/aem.67.12.5520-5525.2001 - SUPPORT (IN_VITRO)
    "Degradation proceeds only if the concentration of hydrogen produced during benzoate oxidation is continuously maintained at a low level by a hydrogen-using microorganism ( 12 , 19 , 24 , 26 )."

Growth Media

sulfate-free benzoate basal medium

Temperature 37 °C
Atmosphere ANAEROBIC

Preparation notes: S. aciditrophicus-M. hungatei cocultures grown in sulfate-free (<5 µM) benzoate basal medium; all media prepared anaerobically by the Balch-Wolfe technique; test substrate at 1.2-1.7 mM. The earlier coculture study used basal medium containing 1.2-1.5 mM sodium benzoate under an 80% N2-20% CO2 headspace.

Evidence

doi:10.1128/aem.67.12.5520-5525.2001

"Cocultures of S. aciditrophicus and M. hungatei were established and grown in sulfate-free (<5 μM) benzoate basal medium as described previously ( 8 )."

doi:10.1128/aem.67.12.5520-5525.2001

"All cultures were incubated at 37°C."

doi:10.1128/aem.67.12.5520-5525.2001

"All media and stock solutions were prepared anaerobically by using the techniques described by Balch and Wolfe ( 3 )."

Cross-Mech Suite Links

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

HabitatMech: anaerobic sediments ↗ TaxonMech: Syntrophus aciditrophicus SB ↗ TraitMech: Syntrophus aciditrophicus SB ↗ TaxonMech: Methanospirillum hungatei ↗ TraitMech: Methanospirillum hungatei ↗ CultureMech Growth Media ↗ PathwayMech Pathways ↗