identifier: METPO:1000636
label: chemoheterotrophic
definition: A trophic type in which an organism obtains both energy and carbon from
  organic compounds.
definition_source: DOI:10.1016/B978-012373944-5.00083-3
trait_category: PHYSIOLOGY
term_kind: CLASS
mapping_status: REVIEWED
parent_traits:
- METPO:1000631
synonyms:
- synonym_text: aerobic_chemo_heterotrophy
  synonym_type: RELATED_SYNONYM
  source: metpo.owl
- synonym_text: chemoheterotroph
  synonym_type: RELATED_SYNONYM
  source: metpo.owl
evidence:
- reference: DOI:10.1016/B978-012373944-5.00083-3
  snippet: Chemoheterotroph (chemoorganoheterotroph)
  notes: Encyclopedia chapter maps chemoheterotrophy to chemical energy and reduced
    organic carbon.
- reference: DOI:10.1021/acsomega.3c02205
  snippet: chemoheterotrophic
  notes: Review table supports chemoheterotrophic use of organic molecules as energy
    and carbon sources.
canonical_examples:
- taxon_id: NCBITaxon:562
  taxon_label: Escherichia coli
  note: "chemoorganoheterotroph"
  reference: PMID:17593909
- taxon_id: NCBITaxon:303
  taxon_label: Pseudomonas putida
  note: "versatile chemoheterotroph"
  reference: PMID:31657101
causal_graphs:
- graph_id: chemoheterotrophic_organic_energy_carbon
  title: Chemoheterotrophic organic energy and carbon metabolism
  description: DOI-backed graph linking organic molecules as chemical energy and carbon
    sources to catabolism, respiration or fermentation, ATP, and biomass.
  nodes:
  - node_id: chemoheterotrophic_trait
    label: chemoheterotrophic
    node_type: TRAIT
    grounding: METPO:1000636
    description: Trophic type obtaining energy and carbon from organic compounds.
  - node_id: organic_molecule
    label: organic molecule
    node_type: CHEMICAL
    description: Reduced organic compound used for energy and carbon.
    grounding: CHEBI:72695
  - node_id: catabolism
    label: catabolism
    node_type: BIOLOGICAL_PROCESS
    grounding: GO:0009056
    description: Breakdown of nutrients to generate energy and biosynthetic precursors.
  - node_id: respiration
    label: respiration
    node_type: PATHWAY
    grounding: METPO:1000800
    description: Electron-transport route for energy conservation.
  - node_id: fermentation
    label: fermentation
    node_type: PATHWAY
    grounding: METPO:1002005
    description: Organic-substrate redox balancing route with substrate-level phosphorylation.
  - node_id: atp
    label: ATP
    node_type: CHEMICAL
    grounding: CHEBI:30616
    description: Energy carrier produced during chemoheterotrophic metabolism.
  - node_id: precursor_metabolites
    label: precursor metabolites
    node_type: CHEMICAL
    description: Central intermediates used for biosynthesis.
  - node_id: biomass
    label: biomass
    node_type: CHEMICAL
    description: Cell material formed from organic carbon.
    grounding: METPO:1007501
  - node_id: emp_glycolysis
    label: Embden-Meyerhof glycolysis pathway
    node_type: PATHWAY
    description: Central glycolytic pathway converting sugars to pyruvate with ATP
      and reducing equivalents.
  - node_id: short_chain_fatty_acids
    label: short-chain fatty acids
    node_type: CHEMICAL
    description: Fermentation end products such as acetate, propionate, and succinate.
    grounding: CHEBI:26666
  - node_id: mannitol_pts
    label: PEP-dependent phosphotransferase system (mannitol PTS)
    node_type: GENE_OR_PROTEIN
    description: PEP-PTS transporter importing and phosphorylating sugar alcohols
      during organotrophic uptake.
  - node_id: mannitol
    label: mannitol
    node_type: CHEMICAL
    description: Sugar alcohol imported and phosphorylated as an organic carbon and
      energy source.
  - node_id: mtld
    label: mtlD mannitol-1-phosphate dehydrogenase
    node_type: GENE_OR_PROTEIN
    description: Enzyme converting mannitol-1-phosphate to fructose-6-phosphate, bridging
      uptake to glycolysis.
  - node_id: fructose_6_phosphate
    label: fructose-6-phosphate
    node_type: CHEMICAL
    description: Glycolytic intermediate entering central carbon catabolism.
  edges:
  - subject: chemoheterotrophic_trait
    predicate: uses energy source
    object: organic_molecule
    description: Chemoheterotrophs derive chemical energy from organic compounds.
    evidence:
    - reference: DOI:10.1021/acsomega.3c02205
      snippet: organic molecules ... energy source
      notes: Supports organic molecules as energy sources in chemoheterotrophic growth.
    predicate_id: METPO:2000010
  - subject: chemoheterotrophic_trait
    predicate: uses carbon source
    object: organic_molecule
    description: Chemoheterotrophs use organic compounds as carbon sources.
    evidence:
    - reference: DOI:10.1016/B978-012373944-5.00083-3
      snippet: reduced organic compound
      notes: Supports organic compounds as carbon sources in chemoheterotrophy.
    predicate_id: METPO:2000006
  - subject: organic_molecule
    predicate: broken down by
    object: catabolism
    description: Organic molecules are catabolized to release energy and precursors.
    evidence:
    - reference: DOI:10.1016/B978-012373944-5.00083-3
      snippet: breakdown of nutrients
      notes: Supports catabolism of organic nutrients.
  - subject: catabolism
    predicate: can proceed through
    object: respiration
    description: Organic catabolism can conserve energy through respiration.
    evidence:
    - reference: DOI:10.1016/j.bbabio.2008.09.008
      snippet: membrane-bound electron transport chain
      notes: Supports respiratory electron transport as an energy-conserving route.
  - subject: catabolism
    predicate: can proceed through
    object: fermentation
    description: Organic catabolism can conserve energy through fermentation.
    evidence:
    - reference: DOI:10.3389/fmicb.2021.703525
      snippet: substrate ... electron donor as well as acceptor
      notes: Supports fermentation of organic substrates without external electron
        acceptors.
  - subject: respiration
    predicate: produces
    object: atp
    description: Respiration supports ATP synthesis.
    evidence:
    - reference: DOI:10.1016/j.bbabio.2008.09.008
      snippet: drives ATP synthesis
      notes: Supports ATP synthesis from respiratory energy conservation.
    predicate_id: METPO:2000202
  - subject: fermentation
    predicate: produces
    object: atp
    description: Fermentation can produce ATP by substrate-level phosphorylation.
    evidence:
    - reference: DOI:10.1111/1751-7915.13746
      snippet: substrate-level phosphorylation
      notes: Supports ATP formation during fermentative metabolism.
    predicate_id: METPO:2000202
  - subject: catabolism
    predicate: produces
    object: precursor_metabolites
    description: Catabolism supplies precursors for biosynthesis.
    evidence:
    - reference: DOI:10.1016/B978-012373944-5.00083-3
      snippet: precursor compounds for anabolism
      notes: Supports catabolism as a source of biosynthetic precursors.
    predicate_id: METPO:2000202
  - subject: precursor_metabolites
    predicate: incorporated into
    object: biomass
    description: Organic-carbon precursors are incorporated into biomass.
    evidence:
    - reference: DOI:10.1016/B978-012373944-5.00083-3
      snippet: incorporation of a compound into biomass
      notes: Supports assimilation of compounds into cell material.
    predicate_id: biolink:part_of
  - subject: emp_glycolysis
    predicate: contributes to
    object: catabolism
    description: Embden-Meyerhof glycolysis is a core route of organic-substrate catabolism
      in chemoheterotrophs.
    evidence:
    - reference: DOI:10.1128/mbio.00992-24
      notes: harbor the Embden-Meyerhof-Parnas glycolysis pathway; broad mechanistic
        core of chemoheterotrophic catabolism.
    predicate_id: RO:0002326
  - subject: fermentation
    predicate: generates
    object: short_chain_fatty_acids
    description: Fermentation of organic substrates yields short-chain fatty acids
      such as acetate, succinate, and propionate.
    evidence:
    - reference: DOI:10.1016/j.chom.2024.05.011
      notes: subsequent fermentation to short-chain fatty acids (acetate, succinate,
        propionate); broadly useful fermentation output edge.
    predicate_id: biolink:produces
  - subject: mannitol_pts
    predicate: imports and phosphorylates
    object: mannitol
    description: A PEP-dependent phosphotransferase system imports and phosphorylates
      mannitol as an organic substrate.
    evidence:
    - reference: DOI:10.1016/j.chom.2024.05.011
      notes: mannitol is imported/phosphorylated via a PEP-PTS to mannitol-1-phosphate;
        canonical organotrophic uptake mechanism.
  - subject: mtld
    predicate: converts
    object: fructose_6_phosphate
    description: mtlD converts mannitol-1-phosphate to fructose-6-phosphate, feeding
      catabolism into glycolysis.
    evidence:
    - reference: DOI:10.1016/j.chom.2024.05.011
      notes: converted by mtlD to fructose-6-phosphate and enters glycolysis; bridge
        from transport to central carbon metabolism.
  - subject: fructose_6_phosphate
    predicate: broken down by
    object: emp_glycolysis
    description: Fructose-6-phosphate is metabolized through the Embden-Meyerhof glycolysis
      pathway.
    evidence:
    - reference: DOI:10.1016/j.chom.2024.05.011
      notes: enters glycolysis; links upstream sugar catabolism to the glycolytic
        pathway.
curation_history:
- timestamp: '2026-05-05T01:35:46.869925+00:00'
  curator: seed_from_metpo
  action: SEEDED_FROM_METPO
  changes: imported from data/raw/metpo.owl (CLASS)
  llm_assisted: false
- timestamp: '2026-05-09T00:00:00-07:00'
  curator: codex
  action: ADDED_CAUSAL_GRAPH
  changes: Added DOI-backed causal graph for organic molecules as energy and carbon
    sources feeding catabolism, respiration or fermentation, ATP, and biomass.
  llm_assisted: true
- timestamp: '2026-05-20T03:35:31Z'
  curator: claude
  action: GROUND_CAUSAL_PREDICATES
  changes: Grounded 5 causal-edge predicate_id field(s) via mappings/predicate_grounding.tsv
    (METPO:2000202×3, METPO:2000010×1, METPO:2000006×1).
  llm_assisted: true
- timestamp: '2026-05-24T04:41:04Z'
  curator: claude
  action: GROUND_CAUSAL_NODES
  changes: Grounded 1 causal-node grounding field(s) via mappings/node_grounding.tsv
    (METPO:1007501×1).
  llm_assisted: true
- timestamp: '2026-05-24T07:34:58Z'
  curator: claude
  action: RETYPE_CAUSAL_NODES
  changes: 'Re-typed 1 causal-node node_type field(s) to align with CausalNodeTypeEnum
    semantics: biomass: BIOLOGICAL_PROCESS → CHEMICAL ×1.'
  llm_assisted: true
- timestamp: '2026-06-13T21:03:27Z'
  curator: claude
  action: GROUND_CAUSAL_PREDICATES
  changes: Grounded 1 causal-edge predicate_id field(s) via mappings/predicate_grounding.tsv
    (biolink:part_of×1).
  llm_assisted: true
- timestamp: '2026-06-14T05:51:47Z'
  curator: claude
  action: GROUND_CAUSAL_NODES
  changes: Grounded 1 causal-node grounding field(s) via mappings/node_grounding.tsv
    (CHEBI:72695×1).
  llm_assisted: true
- timestamp: '2026-06-23T00:00:00Z'
  curator: claude
  action: ENRICH_CAUSAL_GRAPH
  changes: Added 5 evidence-backed generic edges (6 new nodes) from the deep-research
    report.
  llm_assisted: true
- timestamp: '2026-06-24T17:21:14Z'
  curator: claude
  action: GROUND_CAUSAL_PREDICATES
  changes: Grounded 2 causal-edge predicate_id field(s) via mappings/predicate_grounding.tsv
    (RO:0002326×1, biolink:produces×1).
  llm_assisted: true
- timestamp: '2026-06-24T17:23:34Z'
  curator: claude
  action: GROUND_CAUSAL_NODES
  changes: Grounded 1 causal-node grounding field(s) via mappings/node_grounding.tsv
    (CHEBI:26666×1).
  llm_assisted: true