identifier: METPO:1000659
label: photoorganoheterotrophic
definition: A trophic type in which an organism obtains energy from light 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: photoorganoheterotroph
  synonym_type: RELATED_SYNONYM
  source: metpo.owl
evidence:
- reference: DOI:10.1016/B978-0-12-809633-8.20672-9
  snippet: light-induced redox chemistry
  notes: Phototrophy chapter supports light-driven reaction-center electron transfer.
- reference: DOI:10.1021/acsomega.3c02205
  snippet: photoorganoheterotrophic
  notes: Review table classifies photoorganoheterotrophy by light with organic electron
    and carbon sources.
canonical_examples:
- taxon_id: NCBITaxon:1076
  taxon_label: Rhodopseudomonas palustris
  note: "photoorganoheterotroph"
  reference: PMID:14704707
- taxon_id: NCBITaxon:1085
  taxon_label: Rhodospirillum rubrum
  note: "purple non-sulfur photoorganoheterotroph"
  reference: PMID:6042358
causal_graphs:
- graph_id: photoorganoheterotrophic_light_organic_electrons
  title: Photoorganoheterotrophic light and organic substrate use
  description: DOI-backed graph for light-driven energy conservation with organic
    compounds serving as electron and carbon sources.
  nodes:
  - node_id: photoorganoheterotrophic_trait
    label: photoorganoheterotrophic
    node_type: TRAIT
    grounding: METPO:1000659
    description: Trophic type using light energy and organic substrates for electrons
      and carbon.
  - node_id: light
    label: light
    node_type: ENVIRONMENTAL_FACTOR
    description: Energy source for photoorganoheterotrophic metabolism.
    grounding: PATO:0001717
  - node_id: organic_compound
    label: organic compound
    node_type: CHEMICAL
    description: Reduced organic molecule supplying electrons and carbon.
    grounding: CHEBI:50860
  - node_id: photosynthetic_reaction_center
    label: photosynthetic reaction center
    node_type: GENE_OR_PROTEIN
    description: Chlorophyll or bacteriochlorophyll protein complex for photochemistry.
  - node_id: photosynthetic_electron_transport
    label: photosynthetic electron transport
    node_type: PATHWAY
    description: Light-induced pathway forming reductants and ion gradients.
    grounding: GO:0009767
  - node_id: proton_motive_force
    label: proton motive force
    node_type: STATE
    description: Ion gradient generated by electron transport.
    grounding: METPO:1007500
  - node_id: atp
    label: ATP
    node_type: CHEMICAL
    grounding: CHEBI:30616
    description: Energy carrier produced from proton motive force.
  - node_id: biomass
    label: biomass
    node_type: CHEMICAL
    description: Cellular material built from organic carbon.
    grounding: METPO:1007501
  - node_id: rc_charge_separation
    label: reaction center charge separation
    node_type: MOLECULAR_FUNCTION
    description: Light-driven charge separation at the reaction-center special pair.
  - node_id: type_i_reaction_center
    label: Type I reaction center
    node_type: GENE_OR_PROTEIN
    description: Fe-S type photosynthetic reaction-center complex.
  - node_id: fe_s_electron_transfer
    label: electron transfer to Fe-S acceptors
    node_type: BIOLOGICAL_PROCESS
    description: Electron transfer from the reaction center to terminal [4Fe-4S] acceptors.
  - node_id: photosynthesis_gene_cluster
    label: photosynthesis gene cluster (PGC)
    node_type: GENE_OR_PROTEIN
    description: Cluster of bch/crt/puf/puh genes encoding BChl synthesis and photosystem
      components.
  - node_id: bchl_photoheterotrophy
    label: bacteriochlorophyll-based anoxygenic photoheterotrophy
    node_type: PATHWAY
    description: Anoxygenic photoheterotrophy using bacteriochlorophyll-a-containing
      photosystems.
  - node_id: diurnal_cycle
    label: diurnal dark-light cycle
    node_type: ENVIRONMENTAL_FACTOR
    description: Alternating light and dark periods experienced by phototrophs.
  - node_id: rhythmic_transcription
    label: rhythmic transcription
    node_type: BIOLOGICAL_PROCESS
    description: Cyclic, time-of-day-dependent gene transcription.
  - node_id: stationary_phase_survival
    label: survival in stationary phase
    node_type: BIOLOGICAL_PROCESS
    description: Maintenance of viability during nutrient-limited stationary phase.
  edges:
  - subject: photoorganoheterotrophic_trait
    predicate: uses energy source
    object: light
    description: Photoorganoheterotrophy uses light as the energy source.
    evidence:
    - reference: DOI:10.1016/B978-012373944-5.00083-3
      snippet: use of light
      notes: Supports light as the energy source in photoheterotrophy categories.
    predicate_id: METPO:2000010
  - subject: photoorganoheterotrophic_trait
    predicate: uses electron donor
    object: organic_compound
    description: The organotrophic component uses organic molecules as electron donors.
    evidence:
    - reference: DOI:10.1021/acsomega.3c02205
      snippet: organic molecules ... electron source
      notes: Supports organic molecules as the electron source in photoorganoheterotrophic
        growth.
    predicate_id: METPO:2000009
  - subject: photoorganoheterotrophic_trait
    predicate: uses carbon source
    object: organic_compound
    description: The heterotrophic component uses organic molecules as carbon sources.
    evidence:
    - reference: DOI:10.1021/acsomega.3c02205
      snippet: organic molecules ... carbon source
      notes: Supports organic molecules as the carbon source in photoorganoheterotrophic
        growth.
    predicate_id: METPO:2000006
  - subject: light
    predicate: captured by
    object: photosynthetic_reaction_center
    description: Photosynthetic reaction centers convert light into charge separation.
    evidence:
    - reference: DOI:10.1016/B978-0-12-809633-8.20672-9
      snippet: chlorophyll ... reaction center proteins
      notes: Supports reaction centers as the light-driven photochemical machinery.
  - subject: photosynthetic_reaction_center
    predicate: initiates
    object: photosynthetic_electron_transport
    description: Reaction-center photochemistry initiates electron transport.
    evidence:
    - reference: DOI:10.1016/B978-0-12-809633-8.20672-9
      snippet: light-induced redox chemistry
      notes: Supports light-induced redox chemistry leading to electron transfer.
  - subject: photosynthetic_electron_transport
    predicate: generates
    object: proton_motive_force
    description: Electron transport generates an ion gradient.
    evidence:
    - reference: DOI:10.1016/B978-0-12-809633-8.20672-9
      snippet: produce stable reductants ... proton motive force
      notes: Supports proton motive force formation by phototrophic electron transfer.
    predicate_id: biolink:produces
  - subject: proton_motive_force
    predicate: drives production of
    object: atp
    description: Proton motive force supports ATP synthesis.
    evidence:
    - reference: DOI:10.1016/B978-0-12-809633-8.20672-9
      snippet: can be used to produce ATP
      notes: Supports ATP synthesis from phototrophic proton motive force.
    predicate_id: biolink:produces
  - subject: organic_compound
    predicate: assimilated into
    object: biomass
    description: Organic compounds provide carbon for biomass formation.
    evidence:
    - reference: DOI:10.1128/AEM.01747-12
      snippet: supplied organic carbon
      notes: Supports assimilation of organic carbon by photoheterotrophic bacteria.
  - subject: light
    predicate: drives
    object: rc_charge_separation
    description: Light absorption funnels excitation to the special pair, initiating
      charge separation.
    evidence:
    - reference: DOI:10.3390/biom14030311
      notes: Light absorption by LH pigments funnels excitation to the special pair,
        initiating charge separation (general anoxygenic phototrophy mechanism).
  - subject: type_i_reaction_center
    predicate: enables
    object: fe_s_electron_transfer
    description: Type I reaction centers transfer electrons to terminal Fe-S acceptors.
    evidence:
    - reference: DOI:10.3390/biom14030311
      notes: Electrons are transferred directly from A0 to FX, with terminal acceptors
        FA and FB [4Fe-4S] clusters.
    predicate_id: RO:0002327
  - subject: photosynthesis_gene_cluster
    predicate: enables
    object: bchl_photoheterotrophy
    description: PGCs encoding bch/crt/puf/puh support bacteriochlorophyll-based anoxygenic
      photoheterotrophy.
    evidence:
    - reference: DOI:10.1128/spectrum.01112-23
      notes: PGCs include bch and crt genes and puf and puh operons and support anoxygenic
        phototrophy using bacteriochlorophyll-a-containing photosystems.
    predicate_id: RO:0002327
  - subject: diurnal_cycle
    predicate: drives
    object: rhythmic_transcription
    description: Dark-light alternance drives a pervasive pattern of rhythmic transcription.
    evidence:
    - reference: DOI:10.1038/s43705-023-00334-5
      notes: Cyclic variations with a pervasive pattern of rhythmic transcription;
        likely broader to facultative phototrophs.
  - subject: photosynthetic_reaction_center
    predicate: promotes
    object: stationary_phase_survival
    description: Functional reaction centers promote survival in stationary phase.
    evidence:
    - reference: DOI:10.1038/s43705-023-00334-5
      notes: Survival in stationary phase relies on functional reaction centers.
    predicate_id: RO:0002213
curation_history:
- timestamp: '2026-05-05T01:35:46.881966+00:00'
  curator: seed_from_metpo
  action: SEEDED_FROM_METPO
  changes: imported from data/raw/metpo.owl (CLASS)
  llm_assisted: false
- timestamp: '2026-05-08T00:00:00-07:00'
  curator: codex
  action: ADDED_CAUSAL_GRAPH
  changes: Added DOI-backed causal graph for light-driven energy conservation using
    organic compounds as electron and carbon sources.
  llm_assisted: true
- timestamp: '2026-05-20T03:35:32Z'
  curator: claude
  action: GROUND_CAUSAL_PREDICATES
  changes: Grounded 3 causal-edge predicate_id field(s) via mappings/predicate_grounding.tsv
    (METPO:2000010×1, METPO:2000009×1, METPO:2000006×1).
  llm_assisted: true
- timestamp: '2026-05-23T08:21:50Z'
  curator: claude
  action: GROUND_CAUSAL_PREDICATES
  changes: Grounded 1 causal-edge predicate_id field(s) via mappings/predicate_grounding.tsv
    (biolink:produces×1).
  llm_assisted: true
- timestamp: '2026-05-24T04:38:01Z'
  curator: claude
  action: GROUND_CAUSAL_NODES
  changes: Grounded 2 causal-node grounding field(s) via mappings/node_grounding.tsv
    (PATO:0001717×1, GO:0009767×1).
  llm_assisted: true
- timestamp: '2026-05-24T04:41:04Z'
  curator: claude
  action: GROUND_CAUSAL_NODES
  changes: Grounded 2 causal-node grounding field(s) via mappings/node_grounding.tsv
    (METPO:1007500×1, METPO:1007501×1).
  llm_assisted: true
- timestamp: '2026-05-24T07:34:59Z'
  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: '2026-05-24T08:14:33Z'
  curator: claude
  action: GROUND_CAUSAL_NODES
  changes: Grounded 1 causal-node grounding field(s) via mappings/node_grounding.tsv
    (CHEBI:50860×1).
  llm_assisted: true
- timestamp: '2026-05-26T02:30:14Z'
  curator: claude
  action: RETYPE_CAUSAL_NODES
  changes: 'Re-typed 1 causal-node node_type field(s) to align with CausalNodeTypeEnum
    semantics: proton motive force: BIOLOGICAL_PROCESS → STATE ×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:produces×1).
  llm_assisted: true
- timestamp: '2026-06-23T00:00:00Z'
  curator: claude
  action: ENRICH_CAUSAL_GRAPH
  changes: Added 5 evidence-backed generic edges (8 new nodes) from the deep-research
    report.
  llm_assisted: true
- timestamp: '2026-06-24T17:21:15Z'
  curator: claude
  action: GROUND_CAUSAL_PREDICATES
  changes: Grounded 3 causal-edge predicate_id field(s) via mappings/predicate_grounding.tsv
    (RO:0002327×2, RO:0002213×1).
  llm_assisted: true