← Back to Communities

Cellulose-to-Methane Quad-Culture SynCom

Community ID CommunityMech:000089
Ecological State ENGINEERED
Environment laboratory bioreactor
ENVO:01001405

A four-species anaerobic synthetic community coupling cellulose degradation, sulfate reduction, and methanogenesis.

Taxonomy

Taxon Ontology ID Functional Roles Abundance
Ruminiclostridium cellulolyticum NCBITaxon:1521
PRIMARY_DEGRADER
N/A
  • PMID:36847519 - SUPPORT (IN_VITRO)
    "Here, we constructed a quad-culture consisting of a cellulolytic bacterium (Ruminiclostridium cellulolyticum), a hydrogenotrophic methanogen (Methanospirillum hungatei), an acetoclastic methanogen (Methanosaeta concilii), and a sulfate-reducing bacterium (Desulfovibrio vulgaris)."
Methanospirillum hungatei NCBITaxon:323259
SYNTROPHIC_PARTNER
N/A
  • PMID:36847519 - SUPPORT (IN_VITRO)
    "Here, we constructed a quad-culture consisting of a cellulolytic bacterium (Ruminiclostridium cellulolyticum), a hydrogenotrophic methanogen (Methanospirillum hungatei), an acetoclastic methanogen (Methanosaeta concilii), and a sulfate-reducing bacterium (Desulfovibrio vulgaris)."
Methanosaeta concilii NCBITaxon:2223
SYNTROPHIC_PARTNER
N/A
  • PMID:36847519 - SUPPORT (IN_VITRO)
    "Here, we constructed a quad-culture consisting of a cellulolytic bacterium (Ruminiclostridium cellulolyticum), a hydrogenotrophic methanogen (Methanospirillum hungatei), an acetoclastic methanogen (Methanosaeta concilii), and a sulfate-reducing bacterium (Desulfovibrio vulgaris)."
Desulfovibrio vulgaris NCBITaxon:881
SYNTROPHIC_PARTNER
N/A
  • PMID:36847519 - SUPPORT (IN_VITRO)
    "Here, we constructed a quad-culture consisting of a cellulolytic bacterium (Ruminiclostridium cellulolyticum), a hydrogenotrophic methanogen (Methanospirillum hungatei), an acetoclastic methanogen (Methanosaeta concilii), and a sulfate-reducing bacterium (Desulfovibrio vulgaris)."

Ecological Interactions

Ecological interaction network for Cellulose-to-Methane Quad-Culture SynCom Bipartite graph where circle nodes represent taxa and each ecological interaction is drawn as a distinct non-circular symbol, with colour repeating the same distinction (cross-feeding, syntrophy, competition).
Taxon
Cross-feeding
Syntrophy
Competition

Cellulose Cross-Feeding to Methane

CROSS_FEEDING

Evidence

  • PMID:36847519 - SUPPORT (IN_VITRO)
    "Here, we constructed a quad-culture consisting of a cellulolytic bacterium (Ruminiclostridium cellulolyticum), a hydrogenotrophic methanogen (Methanospirillum hungatei), an acetoclastic methanogen (Methanosaeta concilii), and a sulfate-reducing bacterium (Desulfovibrio vulgaris)."

R. cellulolyticum acetate cross-feeding to M. concilii

CROSS_FEEDING

Source Taxon: Ruminiclostridium cellulolyticum

Target Taxon: Methanosaeta concilii

Metabolites: acetate (CHEBI:30089)

Biological Processes:

Downstream Effects:
→ Cellulose Cross-Feeding to Methane

Evidence

  • PMID:36847519 - SUPPORT (IN_VITRO)
    "cross-feeding of acetate from a cellulolytic bacterium to an acetoclastic methanogen"
  • PMID:36847519 - SUPPORT (IN_VITRO)
    "sulfate addition increased both the production of acetate and lactate by R. cellulolyticum and their consumption by M. concilii and D. vulgaris"

R. cellulolyticum lactate cross-feeding to D. vulgaris

CROSS_FEEDING

Source Taxon: Ruminiclostridium cellulolyticum

Target Taxon: Desulfovibrio vulgaris

Metabolites: lactate (CHEBI:24996)

Downstream Effects:
→ D. vulgaris H2 syntrophy to M. hungatei

Evidence

  • PMID:36847519 - SUPPORT (IN_VITRO)
    "These results suggest that D. vulgaris fermented lactate produced by R. cellulolyticum to H2"

D. vulgaris H2 syntrophy to M. hungatei

SYNTROPHY

Source Taxon: Desulfovibrio vulgaris

Target Taxon: Methanospirillum hungatei

Metabolites: dihydrogen (CHEBI:18276)

Biological Processes:

Downstream Effects:
→ Cellulose Cross-Feeding to Methane

Evidence

  • PMID:36847519 - SUPPORT (IN_VITRO)
    "D. vulgaris enhanced hydrogenotrophic methanogenesis, likely by producing additional hydrogen from lactate fermentation"

M. hungatei H2 removal relieves R. cellulolyticum product inhibition

SYNTROPHY

Source Taxon: Methanospirillum hungatei

Target Taxon: Ruminiclostridium cellulolyticum

Metabolites: dihydrogen (CHEBI:18276)

Downstream Effects:
→ R. cellulolyticum acetate cross-feeding to M. concilii

Evidence

  • PMID:36847519 - SUPPORT (IN_VITRO)
    "This indicates that M. hungatei promoted H2 production by R. cellulolyticum through the alleviation of product inhibition"

D. vulgaris–M. hungatei competition for H2

COMPETITION

Source Taxon: Desulfovibrio vulgaris

Target Taxon: Methanospirillum hungatei

Metabolites: dihydrogen (CHEBI:18276), sulfate (CHEBI:16189)

Biological Processes:

Downstream Effects:
→ D. vulgaris H2 syntrophy to M. hungatei
→ Cellulose Cross-Feeding to Methane

Evidence

  • PMID:36847519 - SUPPORT (IN_VITRO)
    "competition of H2 between a sulfate reducing bacterium and a hydrogenotrophic methanogen"
  • PMID:36847519 - SUPPORT (IN_VITRO)
    "the addition of sulfate halted hydrogenotrophic methanogenesis in M. hungatei"
  • PMID:36847519 - SUPPORT (IN_VITRO)
    "The main reason for decreased CH4 production was the sharp decrease in H2 available for the hydrogenotrophic methanogen"

Knowledge gaps & discussions (1)

KNOWLEDGE_GAP OPEN Does D. vulgaris fermentation of lactate to acetate and CO2 causally enhance acetoclastic methanogenesis by M. concilii, i.e. is there a second (D. vulgaris-derived) carbon route to methane beyond the direct R. cellulolyticum → M. concilii hand-off?

If confirmed, D. vulgaris would be a secondary acetate/CO2 supplier to the acetoclastic methanogen, adding a parallel carbon route to methane and changing how the causal graph attributes methane output between the two carbon sources. The source paper proposes it mechanistically ("it may be") but does not demonstrate the D. vulgaris → M. concilii carbon edge directly, so it is recorded here as a knowledge gap rather than asserted as an ecological interaction.

Attaches to: ecological_interactions#R. cellulolyticum acetate cross-feeding to M. concilii

1 evidence item(s)
IN_VITRO PARTIAL PMID:36847519

Mechanistically, it may be that D. vulgaris enhances methanogenesis by producing the substrates CO2, acetate, and H2 and removing lactate

The authors state the D. vulgaris → methanogen carbon contribution as a hypothesis ("it may be"), not a demonstrated causal edge — the basis for filing it as a knowledge gap.

Environmental Factors

Factor Value Unit
defined synthetic community design Rational functional-guild assembly of cellulolytic, sulfate-reducing, hydrogenotrophic methanogenic, and acetoclastic methanogenic members. N/A
  • PMID:36847519 - SUPPORT (IN_VITRO)
    "Here, we constructed a quad-culture consisting of a cellulolytic bacterium (Ruminiclostridium cellulolyticum), a hydrogenotrophic methanogen (Methanospirillum hungatei), an acetoclastic methanogen (Methanosaeta concilii), and a sulfate-reducing bacterium (Desulfovibrio vulgaris)."

Growth Media

modified VM medium (10 g/L cellulose as sole carbon source)

Temperature 34 °C
Atmosphere ANAEROBIC

Preparation notes: All cultures grown anaerobically in triplicate on cellulose as the sole carbon source; about 5 × 10^7 cells inoculated per species; sulfate-perturbation treatment received additional sulfate versus the control condition.

Evidence

PMID:36847519

"All fermentation experiments were carried out in 160 mL serum bottles with 20 mL of modified VM medium containing 10 g/L cellulose; the chamber gas contained 3% H2 and 97% N2."

PMID:36847519

"All cultures were incubated at 34°C with shaking at 200 rpm for 7 days and sampled each day."

PMID:36847519

"All cultures were grown anaerobically in triplicate using the same medium with cellulose as the sole carbon source."