identifier: METPO:1000658
label: photolithotrophic
definition: A trophic type in which an organism uses light as the energy source and
  inorganic compounds as electron donors, typically with carbon dioxide as the primary
  carbon source.
definition_source: DOI:10.3390/antiox10060829
trait_category: PHYSIOLOGY
term_kind: CLASS
mapping_status: REVIEWED
parent_traits:
- METPO:1000631
synonyms:
- synonym_text: photolithotroph
  synonym_type: RELATED_SYNONYM
  source: metpo.owl
created_by: Luke Wang
evidence:
- reference: DOI:10.3390/antiox10060829
  snippet: anoxygenic photosynthesis
  notes: Review supports light-driven oxidation of reduced sulfur compounds by photolithotrophic
    sulfur bacteria.
- reference: DOI:10.3389/fmicb.2017.00323
  snippet: light as an energy source and reduced iron
  notes: Review supports Fe(II) as an inorganic electron donor for photoferrotrophy.
canonical_examples:
- taxon_id: NCBITaxon:1148
  taxon_label: Synechocystis sp. PCC 6803
  note: "oxygenic photolithotroph"
  reference: PMID:8905231
- taxon_id: NCBITaxon:1097
  taxon_label: Chlorobaculum tepidum
  note: "anoxygenic photolithotroph"
  reference: PMID:12093901
causal_graphs:
- graph_id: photolithotrophic_inorganic_electron_donors
  title: Photolithotrophic inorganic electron donor photosynthesis
  description: DOI-backed graph linking light capture, inorganic electron donors such
    as sulfide and Fe(II), anoxygenic photosynthetic electron transport, and CO2 assimilation.
  nodes:
  - node_id: photolithotrophic_trait
    label: photolithotrophic
    node_type: TRAIT
    grounding: METPO:1000658
    description: Trophic type using light energy and inorganic electron donors.
  - node_id: light
    label: light
    node_type: ENVIRONMENTAL_FACTOR
    description: Energy source for photolithotrophic metabolism.
    grounding: PATO:0001717
  - node_id: inorganic_electron_donor
    label: inorganic electron donor
    node_type: CHEMICAL
    description: Reduced inorganic substrate supplying electrons.
    grounding: METPO:1007502
  - node_id: hydrogen_sulfide
    label: hydrogen sulfide
    node_type: CHEMICAL
    grounding: CHEBI:16136
    description: Reduced sulfur electron donor for sulfur phototrophs.
  - node_id: ferrous_iron
    label: ferrous iron
    node_type: CHEMICAL
    description: Fe(II), an inorganic electron donor in photoferrotrophy.
    grounding: CHEBI:29033
  - node_id: anoxygenic_photosynthesis
    label: anoxygenic photosynthesis
    node_type: PATHWAY
    description: Photosynthetic electron transport that does not evolve oxygen.
  - node_id: carbon_dioxide
    label: carbon dioxide
    node_type: CHEMICAL
    grounding: CHEBI:16526
    description: Inorganic carbon source often fixed by photolithotrophs.
  - node_id: biomass
    label: biomass
    node_type: CHEMICAL
    description: Cell material formed from fixed carbon.
    grounding: METPO:1007501
  - node_id: photosynthetic_reaction_center
    label: photosynthetic reaction center
    node_type: GENE_OR_PROTEIN
    description: Pigment-protein complex that captures light quanta and drives charge
      separation in anoxygenic photosynthesis.
  - node_id: hydrogen_sulfide_oxidation
    label: hydrogen sulfide oxidation
    node_type: BIOLOGICAL_PROCESS
    description: Oxidation of H2S during phototrophic sulfur metabolism.
  - node_id: elemental_sulfur
    label: elemental sulfur
    node_type: CHEMICAL
    description: Product of phototrophic hydrogen sulfide oxidation.
    grounding: CHEBI:26833
  - node_id: co2_fixation
    label: photosynthetic CO2 fixation
    node_type: BIOLOGICAL_PROCESS
    description: Assimilation of inorganic carbon into biomass during anoxygenic photosynthetic
      growth.
  - node_id: ferrous_iron_oxidation
    label: Fe(II) oxidation
    node_type: BIOLOGICAL_PROCESS
    description: Oxidation of reduced iron coupled to anoxygenic photosynthesis.
  - node_id: photoferrotrophy
    label: photoferrotrophy
    node_type: TRAIT
    description: Photolithotrophic subtype oxidizing Fe(II) via anoxygenic photosynthesis.
  edges:
  - subject: photolithotrophic_trait
    predicate: uses energy source
    object: light
    description: Photolithotrophic growth is powered by light.
    evidence:
    - reference: DOI:10.3389/fmicb.2017.00323
      snippet: light as an energy source
      notes: Supports light as the energy source for photoferrotrophic photolithotrophy.
    predicate_id: METPO:2000010
  - subject: photolithotrophic_trait
    predicate: uses electron donor
    object: inorganic_electron_donor
    description: Lithotrophic phototrophs use inorganic electron donors.
    evidence:
    - reference: DOI:10.3390/antiox10060829
      snippet: oxidizes reduced sulfur compounds
      notes: Supports inorganic reduced sulfur compounds as electron donors.
    predicate_id: METPO:2000009
  - subject: hydrogen_sulfide
    predicate: example of
    object: inorganic_electron_donor
    description: Hydrogen sulfide is a representative inorganic electron donor.
    evidence:
    - reference: DOI:10.3390/antiox10060829
      snippet: hydrogen sulfide
      notes: Supports H2S as a photolithotrophic sulfur-bacteria substrate.
    predicate_id: rdfs:subClassOf
  - subject: ferrous_iron
    predicate: example of
    object: inorganic_electron_donor
    description: Fe(II) is a representative inorganic electron donor in photoferrotrophy.
    evidence:
    - reference: DOI:10.3389/fmicb.2017.00323
      snippet: reduced iron [Fe(II)] as an electron donor
      notes: Supports Fe(II) as an inorganic electron donor for anoxygenic photosynthesis.
    predicate_id: rdfs:subClassOf
  - subject: inorganic_electron_donor
    predicate: feeds electrons into
    object: anoxygenic_photosynthesis
    description: Inorganic donors supply electrons to anoxygenic photosynthetic metabolism.
    evidence:
    - reference: DOI:10.3390/antiox10060829
      snippet: electron donor
      notes: Supports donor oxidation during anoxygenic photosynthesis.
    predicate_id: METPO:2007402
  - subject: light
    predicate: enables
    object: anoxygenic_photosynthesis
    description: Light powers anoxygenic photosynthetic electron transport.
    evidence:
    - reference: DOI:10.3390/antiox10060829
      snippet: deriving energy from photosynthesis
      notes: Supports photosynthetic energy capture in photolithotrophic sulfur bacteria.
    predicate_id: RO:0002327
  - subject: carbon_dioxide
    predicate: fixed during
    object: anoxygenic_photosynthesis
    description: Many photolithotrophs reduce CO2 during photosynthetic growth.
    evidence:
    - reference: DOI:10.3390/antiox10060829
      snippet: carbon dioxide
      notes: Supports CO2 use with inorganic substrate conversion to organic matter.
  - subject: anoxygenic_photosynthesis
    predicate: produces
    object: biomass
    description: Fixed carbon supports biomass formation.
    evidence:
    - reference: DOI:10.3389/fmicb.2017.00323
      snippet: inorganic carbon is fixed into organic matter
      notes: Supports organic matter formation from inorganic carbon in photoferrotrophy.
    predicate_id: METPO:2000202
  - subject: light
    predicate: provides energy to
    object: photosynthetic_reaction_center
    description: Light quanta excite the photosynthetic reaction center to drive electron
      transport.
    evidence:
    - reference: DOI:10.3389/fmicb.2024.1417714
      notes: Anoxygenic photosynthesis proceeds from capture of a light quantum through
        transport of an excited electron.
  - subject: hydrogen_sulfide
    predicate: acts as electron donor for
    object: anoxygenic_photosynthesis
    description: H2S is the main electron donor in sulfur-based anoxygenic photosynthesis.
    evidence:
    - reference: DOI:10.3389/fmicb.2024.1417714
      notes: In anoxygenic photosynthesis, hydrogen sulfide (H2S) is used as the main
        electron donor.
  - subject: hydrogen_sulfide_oxidation
    predicate: produces
    object: elemental_sulfur
    description: Phototrophic oxidation of H2S yields elemental sulfur.
    evidence:
    - reference: DOI:10.3389/fmicb.2024.1417714
      notes: GSB oxidize H2S to elemental sulfur.
    predicate_id: METPO:2000202
  - subject: inorganic_electron_donor
    predicate: supports
    object: co2_fixation
    description: Oxidation of reduced sulfur compounds supports photosynthetic CO2
      fixation.
    evidence:
    - reference: DOI:10.3390/life14050591
      notes: Oxidize sulfide, thiosulfate, and elemental sulfur for photosynthetic
        growth (anoxygenic photosynthetic CO2 fixation).
  - subject: ferrous_iron_oxidation
    predicate: defines
    object: photoferrotrophy
    description: Photoferrotrophy is the oxidation of reduced iron via anoxygenic
      photosynthesis.
    evidence:
    - reference: DOI:10.1038/s41561-024-01560-9
      notes: Photoferrotrophy is the oxidation of reduced iron via anoxygenic photosynthesis;
        anoxygenic phototrophic Fe(II) oxidizers are photoferrotrophs.
    predicate_id: METPO:2007500
curation_history:
- timestamp: '2026-05-05T01:35:46.881359+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 anoxygenic photosynthesis
    with sulfide and Fe(II) as inorganic electron donors.
  llm_assisted: true
- timestamp: '2026-05-20T03:35:31Z'
  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:2000202×1).
  llm_assisted: true
- timestamp: '2026-05-23T08:21:50Z'
  curator: claude
  action: GROUND_CAUSAL_PREDICATES
  changes: Grounded 2 causal-edge predicate_id field(s) via mappings/predicate_grounding.tsv
    (rdfs:subClassOf×2).
  llm_assisted: true
- timestamp: '2026-05-23T21:30:07Z'
  curator: claude
  action: GROUND_CAUSAL_PREDICATES
  changes: Grounded 1 causal-edge predicate_id field(s) via mappings/predicate_grounding.tsv
    (METPO:2007402×1).
  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, CHEBI:29033×1).
  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:1007502×1, 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: '2026-05-26T05:00:48Z'
  curator: claude
  action: RENAME_PREDICATE_LABELS
  changes: 'Renamed 1 causal-edge predicate label(s) to align with existing groundings:
    powers → enables ×1.'
  llm_assisted: true
- timestamp: '2026-05-26T05:00:51Z'
  curator: claude
  action: GROUND_CAUSAL_PREDICATES
  changes: Grounded 1 causal-edge predicate_id field(s) via mappings/predicate_grounding.tsv
    (RO:0002327×1).
  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: '2026-06-24T17:21:15Z'
  curator: claude
  action: GROUND_CAUSAL_PREDICATES
  changes: Grounded 2 causal-edge predicate_id field(s) via mappings/predicate_grounding.tsv
    (METPO:2000202×1, METPO:2007500×1).
  llm_assisted: true
- timestamp: '2026-06-24T17:21:20Z'
  curator: claude
  action: GROUND_CAUSAL_NODES
  changes: Grounded 1 causal-node grounding field(s) via mappings/node_grounding.tsv
    (CHEBI:26833×1).
  llm_assisted: true