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Clostridium carboxidivorans-Clostridium kluyveri CO Chain-Elongation Coculture

Community ID CommunityMech:000266
Ecological State ENGINEERED
Environment anaerobic CO-fed laboratory stirred-tank bioreactor — ontology label: laboratory environment
ENVO:01001405 · HabitatMech ↗

A defined anaerobic synthetic coculture pairing the autotrophic solventogenic acetogen Clostridium carboxidivorans with the chain-elongating bacterium Clostridium kluyveri. In CO/CO2-fed stirred-tank bioreactors, C. kluyveri elongates C2 products to organic acids, and C. carboxidivorans reduces those acids to longer-chain alcohols such as butanol and hexanol. The system is DOE-relevant because it couples waste-gas/syngas fermentation, carbon utilization, and production of liquid fuels and platform chemicals.

Taxonomy

Taxon Ontology ID Functional Roles Abundance
Clostridium carboxidivorans NCBITaxon:217159 · TaxonMech · TraitMech
PRIMARY_PRODUCER CROSS_FEEDER
ABUNDANT
  • PMID:34669248 - SUPPORT (IN_VITRO)
    "Clostridium carboxidivorans and Clostridium kluyveri"
  • PMID:37110426 - SUPPORT (IN_VITRO)
    "increased autotrophic growth and ethanol formation by Clostridium carboxidivorans"
Clostridium kluyveri NCBITaxon:1534 · TaxonMech · TraitMech
CROSS_FEEDER
ABUNDANT
  • PMID:34669248 - SUPPORT (IN_VITRO)
    "Clostridium carboxidivorans and Clostridium kluyveri"
  • PMID:37110426 - SUPPORT (IN_VITRO)
    "Clostridium kluyveri monocultures in batch operated stirred-tank bioreactors"

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 Clostridium carboxidivorans-Clostridium kluyveri CO Chain-Elongation Coculture Bipartite graph where circles represent taxa and non-circular symbols represent interactions, with distinct shapes and colours for cross-feeding. Rare or untyped interactions share the Other symbol; exact curated types remain in the interaction details.
Taxon
Cross-feeding
Other

Acetogen-Chain Elongator Product Coupling

CROSS_FEEDING

C. carboxidivorans produces acetate and ethanol from CO/CO2 gas fermentation, supplying C. kluyveri chain elongation to butyrate and hexanoate. Exact-pair batch product profiles and the continuous cascade support this cross-feeding model. Restricted C. kluyveri growth at high CO does not mean absence of chain-elongation activity, and C. carboxidivorans can also form C4/C6 products under appropriate conditions.

Source Taxon: Clostridium carboxidivorans

Target Taxon: Clostridium kluyveri

Metabolites: carbon monoxide (CHEBI:17245 · MediaIngredientMech · CMMMech), carbon dioxide (CHEBI:16526 · MediaIngredientMech · CMMMech), acetate (CHEBI:30089 · MediaIngredientMech · CMMMech), ethanol (CHEBI:16236 · MediaIngredientMech · CMMMech)

Biological Processes:

Downstream Effects:
→ Organic Acid Reduction to Longer-Chain Alcohols

C. carboxidivorans C2-product fermentation feeds C. kluyveri chain elongation, whose organic acid products are then reduced back by C. carboxidivorans to longer-chain alcohols.

Evidence

  • PMID:34669248 - SUPPORT (IN_VITRO)
    "Syngas fermentation with acetogens is known to produce mainly acetate and ethanol efficiently"
  • PMID:37110426 - SUPPORT (IN_VITRO)
    "growth and chain elongation in the first bioreactor"

Organic Acid Reduction to Longer-Chain Alcohols

CROSS_FEEDING

C. kluyveri-derived organic acids supply C. carboxidivorans for reduction to butanol and hexanol. At pH 6.0 and 800 mbar inlet CO, the 144-hour batch coculture had about three times the final butanol and detectable hexanol relative to its matched acetogen-only control. This is a condition-specific comparison, not universal monoculture incapacity: the cascade study also measured alcohol production with C. carboxidivorans alone. Acid reduction contributes to output alongside de novo alcohol synthesis by the acetogen.

Source Taxon: Clostridium kluyveri

Target Taxon: Clostridium carboxidivorans

Metabolites: butyrate (CHEBI:17968 · MediaIngredientMech · CMMMech), hexanoate (CHEBI:17120 · MediaIngredientMech · CMMMech), 1-butanol (CHEBI:28885 · MediaIngredientMech · CMMMech), 1-hexanol (CHEBI:87393 · MediaIngredientMech · CMMMech)

Biological Processes:

Evidence

  • PMID:34669248 - SUPPORT (IN_VITRO)
    "Organic acids produced by C. kluyveri were reduced by C. carboxidivorans to the corresponding alcohols butanol and hexanol"
  • PMID:34669248 - SUPPORT (IN_VITRO)
    "threefold increase in final butanol concentration and enabled hexanol production"

Engineered CO and pH staging of chain elongation and alcohol formation

The engineered continuous cascade used a first reactor at pH 6.0, 100 mbar inlet CO and added sulfide, followed by a second reactor at pH 5.0 and 800 mbar inlet CO. Gas flow and dilution rate also differed. The first stage supported growth and chain elongation; the second supported organic-acid reduction and de novo alcohol synthesis, while C. kluyveri growth was negligible. This is a measured process configuration, not evidence of ecological niche partitioning or an isolated CO-only effect.

Metabolites: carbon monoxide (CHEBI:17245 · MediaIngredientMech · CMMMech), ethanol (CHEBI:16236 · MediaIngredientMech · CMMMech), 1-butanol (CHEBI:28885 · MediaIngredientMech · CMMMech), 1-hexanol (CHEBI:87393 · MediaIngredientMech · CMMMech)

Downstream Effects:
→ Organic Acid Reduction to Longer-Chain Alcohols

The first stage supplies chain-elongated organic acids to the second, whose combined pH-5.0/high-CO conditions support C. carboxidivorans reduction to alcohols. Product balances also indicate de novo alcohol synthesis, so downstream alcohol output is not all explained by reduction of incoming acids; the design does not isolate the contribution of CO from the other changed operating conditions.

Evidence

  • PMID:37110426 - SUPPORT (IN_VITRO)
    "100 mbar CO and additional sulfide supply enabled growth and chain elongation in the first bioreactor"
  • PMID:37110426 - SUPPORT (IN_VITRO)
    "800 mbar CO resulted in an efficient reduction of organic acids and de-novo synthesis of C2-C6 alcohols"

Associated Datasets

Dataset Type Repository Accession
Batch stirred-tank C. carboxidivorans-C. kluyveri FISH-FC coculture study
PubMed/PMC-indexed synthetic coculture study using FISH-FC to monitor C. carboxidivorans and C. kluyveri under CO/CO2-fed batch bioreactor conditions. 		PHENOTYPE OTHER PMID:34669248
Continuous reactor cascade C. carboxidivorans-C. kluyveri alcohol production study
PubMed/PMC-indexed follow-up using the same C. carboxidivorans and C. kluyveri species pair in a two-stage continuous stirred-tank reactor cascade for ethanol, butanol, and hexanol production from CO. 		PHENOTYPE OTHER PMID:37110426

Knowledge gaps & discussions (1)

KNOWLEDGE_GAP OPEN How do CO, pH and residence time separately control cross-feeding and de novo alcohol synthesis?

PMID:37110426 changes several operating conditions between cascade stages. Matched monoculture and coculture products support the process outcomes, but do not isolate each control variable or trace every carbon flux. Its abstract states complete C. kluyveri growth inhibition at 100 mbar CO; Results instead report an 86% maximum-biomass reduction there and complete inhibition at 800 mbar, while chain elongation continues. Keep this source discrepancy and growth/activity distinction explicit. Partner-resolved flux and factorial controls would separate these contributions.

Attaches to: ecological_interactions#Acetogen-Chain Elongator Product Coupling, ecological_interactions#Organic Acid Reduction to Longer-Chain Alcohols, ecological_interactions#Engineered CO and pH staging of chain elongation and alcohol formation

Environmental Factors

Factor Value Unit
CO partial pressure 100 mbar and 800 mbar CO process zones N/A
  • PMID:37110426 - SUPPORT (IN_VITRO)
    "100 mbar CO and additional sulfide supply enabled growth and chain elongation"
  • PMID:37110426 - SUPPORT (IN_VITRO)
    "800 mbar CO resulted in an efficient reduction of organic acids"
Continuous CO/CO2 gassing continuous CO/CO2 gassing N/A
  • PMID:34669248 - SUPPORT (IN_VITRO)
    "continuous CO/CO2 -gassing"
Sulfide supply additional sulfide supply N/A
  • PMID:37110426 - SUPPORT (IN_VITRO)
    "A continuous supply of sulfide led to increased autotrophic growth and ethanol formation by Clostridium carboxidivorans"
pH pH 6.0 chain elongation condition N/A
  • PMID:34669248 - SUPPORT (IN_VITRO)
    "chain elongation activity was observed at pH 6.0"

Growth Media

Anaerobic CO/CO2-fed clostridial stirred-tank coculture

Atmosphere ANAEROBIC

Composition

Component Concentration Unit CHEBI
Carbon monoxide · MediaIngredientMech N/A N/A CHEBI:17245
Carbon dioxide · MediaIngredientMech N/A N/A CHEBI:16526
Ethanol · MediaIngredientMech N/A N/A CHEBI:16236
Acetate · MediaIngredientMech N/A N/A CHEBI:30089

Preparation notes: The curated culture context is anaerobic stirred-tank bioreactor cocultivation with continuous CO/CO2 gassing; exact mineral salts are not asserted here.

Evidence

PMID:34669248

"batch-operated stirred-tank bioreactors with continuous CO/CO2 -gassing"

PMID:37110426

"continuously operated cascade of two stirred-tank reactors"

Cross-Mech Suite Links

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

HabitatMech: anaerobic CO-fed laboratory stirred-tank bioreactor ↗ TaxonMech: Clostridium carboxidivorans ↗ TraitMech: Clostridium carboxidivorans ↗ TaxonMech: Clostridium kluyveri ↗ TraitMech: Clostridium kluyveri ↗ CultureMech Growth Media ↗ PathwayMech Pathways ↗