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Methylocystis-Rhodococcus Methane VFA PHBV Coculture

Community ID CommunityMech:000204
Ecological State ENGINEERED
Environment methane-fed laboratory bioreactor coculture
ENVO:01001405

A defined synthetic coculture pairing the type II methanotroph Methylocystis parvus with the heterotrophic bacterium Rhodococcus opacus for methane-linked polyhydroxyalkanoate production. The coculture was first evaluated for methane-to-poly(3-hydroxybutyrate) conversion and then used in a two-stage PHBV accumulation strategy with nutrient starvation, methane, oxygen or air, valeric acid, and a volatile fatty acid mixture containing acetic, propionic, butyric, and valeric acids. The system is relevant to methane valorization, waste-derived volatile fatty acid upgrading, and biopolymer production.

Taxonomy

Taxon Ontology ID Functional Roles Abundance
Methylocystis parvus NCBITaxon:134
PRIMARY_DEGRADER
ABUNDANT
Rhodococcus opacus NCBITaxon:37919
CROSS_FEEDER
ABUNDANT

Ecological Interactions

Ecological interaction network for Methylocystis-Rhodococcus Methane VFA PHBV Coculture Bipartite graph where circle nodes represent taxa and colored rectangles represent ecological interactions (cross-feeding, mutualism, syntrophy, competition, commensalism).
Taxon
Cross-feeding
Mutualism
Syntrophy
Competition
Commensalism
Niche partitioning
Colonization facilitation
Strain competition
Predation

Methane-Linked PHBV Accumulation

CROSS_FEEDING

Source Taxon: Methylocystis parvus

Target Taxon: Rhodococcus opacus

Metabolites: methane (CHEBI:16183), oxygen (CHEBI:15379), valeric acid (CHEBI:17418), poly(3-hydroxybutyrate) (CHEBI:53389)

Biological Processes:

Evidence

  • PMID:38516398 - SUPPORT (IN_VITRO)
    "mixture of VFAs supported PHBV accumulation"
  • PMID:38516398 - SUPPORT (IN_VITRO)
    "only in the presence of methane"

External Resources

Name Repository Resource ID
Exact-system PHBV primary publication
Primary 2024 publication reporting M. parvus and R. opacus cocultivation for PHBV accumulation from methane and volatile fatty acid cosubstrates. 		OTHER PMID:38516398
  • PMID:38516398 - SUPPORT (IN_VITRO)
    "synthesize poly(3-hydroxybutyrate-co-3-hydroxyvalerate)"
Exact-system DOI landing page
DOI for the ACS Sustainable Chemistry and Engineering PHBV coculture study. 		OTHER doi:10.1021/acssuschemeng.3c08570
  • PMID:38516398 - SUPPORT (IN_VITRO)
    "DOI: 10.1021/acssuschemeng.3c08570"
Earlier exact-species methane-to-PHB coculture publication
Earlier Chemical Engineering Journal study that included the same exact Methylocystis parvus and Rhodococcus opacus species-pair composition for methane-to-PHB conversion, before the PHBV/VFA follow-up. 		OTHER doi:10.1016/j.cej.2023.146646

Environmental Factors

Factor Value Unit
Methane and oxygen headspace CH4:O2 headspace or air N/A
  • PMID:38516398 - SUPPORT (IN_VITRO)
    "under a CH4:O2 or air atmosphere"
VFA cosubstrate composition valeric acid or mixed acetate, propionate, butyrate, and valeric acid N/A
  • PMID:38516398 - SUPPORT (IN_VITRO)
    "acetic, propionic, butyric, and valeric acids"
Nutrient starvation and pH control nitrogen-free medium with pH adjusted to 7 N/A

Growth Media

Methane-fed VFA PHBV accumulation medium

Atmosphere AEROBIC

Composition

Component Concentration Unit CHEBI
methane N/A N/A CHEBI:16183
oxygen N/A N/A CHEBI:15379
acetate N/A N/A CHEBI:30089
propionate N/A N/A CHEBI:17272
butyrate N/A N/A CHEBI:17968
valeric acid N/A N/A CHEBI:17418

Preparation notes: M. parvus and R. opacus were grown as active inocula, then coculture biomass was transferred to nitrogen-free mineral salt medium supplemented with valeric acid or a mixed VFA cosubstrate for PHBV accumulation; pH was adjusted to 7.

Evidence

PMID:38516398

"nutrient starvation in a medium enriched"

PMID:38516398

"under a CH4:O2 or air atmosphere"