identifier: traitmech:000193 label: photoferrotrophy definition: A metabolism in which anoxygenic phototrophs use light energy to oxidize Fe(II) as an electron donor for carbon fixation and biomass formation. definition_source: DOI:10.3389/fmicb.2014.00713 trait_category: METABOLISM term_kind: CLASS mapping_status: PROPOSED parent_traits: - traitmech:000035 - traitmech:000107 synonyms: - synonym_text: phototrophic Fe(II) oxidation synonym_type: EXACT_SYNONYM source: DOI:10.3389/fmicb.2014.00713 - synonym_text: anoxygenic phototrophic Fe(II) oxidation synonym_type: EXACT_SYNONYM source: DOI:10.3389/fmicb.2017.00323 evidence: - reference: DOI:10.3389/fmicb.2014.00713 snippet: photoferrotrophic bacteria use light as energy and Fe(II) as an electron source for carbon fixation and biomass formation notes: Walter et al. directly describe the defining light-powered Fe(II)-donor physiology of photoferrotrophic bacteria. - reference: DOI:10.3389/fmicb.2017.00323 snippet: reduced iron [Fe(II)] as an electron donor notes: Camacho et al. review Fe(II) as the inorganic electron donor used by photoferrotrophs during anoxygenic photosynthesis. - reference: DOI:10.1128/JB.00776-06 snippet: that is necessary for phototrophic Fe(II) oxidation notes: Jiao & Newman discovered the R. palustris TIE-1 pio operon and showed that it is necessary for phototrophic Fe(II) oxidation. canonical_examples: - taxon_id: NCBITaxon:395960 taxon_label: Rhodopseudomonas palustris TIE-1 note: PioABC-model purple nonsulfur photoferrotroph. reference: DOI:10.1128/JB.00776-06 causal_graphs: - graph_id: photoferrotrophy_light_feii_oxidation title: Photoferrotrophy couples light to Fe(II) oxidation description: Evidence-backed causal sketch linking light, Fe(II) oxidation, photosynthetic electron transport, and carbon fixation in photoferrotrophic metabolism. scope_status: NONMECHANISTIC scope_notes: The graph captures the shared light, Fe(II)-donor, Fe(III) product, and carbon-fixation processes. It stays process-level because lineage-specific PioABC, FoxEYZ, and Cyc2 branches do not yet have a reviewed or audit-verifiable exact UniProt protein example for this TraitRecord. nodes: - node_id: photoferrotrophy_trait label: photoferrotrophy node_type: TRAIT grounding: traitmech:000193 description: Anoxygenic photosynthetic Fe(II)-oxidizing metabolism. - node_id: light label: light node_type: ENVIRONMENTAL_FACTOR grounding: PATO:0001717 description: Energy source for anoxygenic phototrophic Fe(II) oxidation. - node_id: ferrous_iron label: ferrous iron node_type: CHEMICAL grounding: CHEBI:29033 description: Fe(II), the electron-donor substrate. - node_id: ferric_iron label: ferric iron node_type: CHEMICAL grounding: CHEBI:29034 description: Fe(III), the oxidized iron product. - node_id: photosynthetic_electron_transport label: photosynthetic electron transport node_type: PATHWAY grounding: GO:0009767 description: Light-driven electron-transport chain powered by photochemical reaction centers. - node_id: carbon_fixation label: carbon fixation node_type: BIOLOGICAL_PROCESS grounding: GO:0015977 description: Inorganic carbon assimilation into organic compounds. - node_id: carbon_dioxide label: carbon dioxide node_type: CHEMICAL grounding: CHEBI:16526 description: Inorganic carbon source fixed by photoferrotrophs. - node_id: biomass label: biomass node_type: CHEMICAL grounding: METPO:1007501 description: Cell material formed from fixed carbon. edges: - subject: photoferrotrophy_trait predicate: has energy source object: light description: Photoferrotrophy uses light as the metabolism's energy source. evidence: - reference: DOI:10.3389/fmicb.2014.00713 snippet: photoferrotrophic bacteria use light as energy notes: Verified against the open Frontiers primary article full text. predicate_id: METPO:2007807 - subject: photoferrotrophy_trait predicate: has electron donor object: ferrous_iron description: Fe(II) is the electron donor for photoferrotrophy. evidence: - reference: DOI:10.3389/fmicb.2017.00323 snippet: reduced iron [Fe(II)] as an electron donor notes: Supports Fe(II) as the inorganic electron donor for anoxygenic photoferrotrophy. predicate_id: METPO:2007701 - subject: light predicate: enables object: photosynthetic_electron_transport description: Light powers the photosynthetic electron flow in photoferrotrophic metabolism. evidence: - reference: DOI:10.3389/fmicb.2014.00713 snippet: photoferrotrophic bacteria use light as energy notes: Supports light as the energetic input for the photoferrotrophic electron-transport chain. predicate_id: RO:0002327 - subject: ferrous_iron predicate: feeds electrons into object: photosynthetic_electron_transport description: Fe(II) supplies electrons to anoxygenic photosynthetic electron transport in photoferrotrophs. evidence: - reference: DOI:10.3389/fmicb.2014.00713 snippet: Fe(II) as an electron source for carbon fixation and biomass formation notes: Supports ferrous iron as the electron source feeding photoferrotrophic carbon fixation. predicate_id: METPO:2007402 - subject: ferrous_iron predicate: oxidized to object: ferric_iron description: Photoferrotrophy oxidizes Fe(II) to Fe(III). evidence: - reference: DOI:10.1128/JB.00776-06 snippet: phototrophic Fe(II) oxidation in Rhodopseudomonas palustris TIE-1 notes: Supports Fe(II) oxidation by the model R. palustris TIE-1 photoferrotrophy system. predicate_id: METPO:2007405 - subject: photosynthetic_electron_transport predicate: enables object: carbon_fixation description: Light-driven electron transport supports carbon fixation in photoferrotrophic metabolism. evidence: - reference: DOI:10.3389/fmicb.2014.00713 snippet: Fe(II) as an electron source for carbon fixation notes: Supports electron flow from Fe(II) into photoferrotrophic carbon fixation. predicate_id: RO:0002327 - subject: carbon_dioxide predicate: fixed during object: carbon_fixation description: Photoferrotrophs assimilate inorganic carbon by carbon fixation. evidence: - reference: DOI:10.3389/fmicb.2017.00323 snippet: inorganic carbon is fixed into organic matter notes: Supports carbon fixation during photoferrotrophic anoxygenic photosynthesis. - subject: carbon_fixation predicate: has output object: biomass description: Carbon fixed during photoferrotrophy supports biomass formation. evidence: - reference: DOI:10.3389/fmicb.2014.00713 snippet: photoferrotrophic bacteria use light as energy and Fe(II) as an electron source for carbon fixation and biomass formation notes: Supports biomass formation coupled to Fe(II)-fed photoferrotrophic metabolism. predicate_id: RO:0002234 discussions: - discussion_id: photoferrotrophy-xref-gap prompt: Resolve an exact external ontology class for photoferrotrophy before adding a TraitRecord xref. kind: CURATION_TODO status: OPEN rationale: The pinned METPO snapshot has no active photoferrotrophy or anoxygenic phototrophic Fe(II) oxidation class. Candidate GO classes for photosynthesis, photosynthetic electron transport, and carbon fixation are broader than this Fe(II)-donor organismal metabolism, so no exact external class has yet been resolved. posed_by: codex posed_date: '2026-09-14' - discussion_id: photoferrotrophy-protein-example-gap prompt: Resolve a live, audit-clean UniProt protein example for a taxon-specific photoferrotrophy branch. kind: CURATION_TODO status: OPEN rationale: R. palustris TIE-1 PioA and R. ferrooxidans SW2 FoxE have DOI-backed primary evidence, but their current exact UniProtKB accessions are unreviewed entries without live Proteomes cross-references. The first graph therefore stays process-level until a reviewed or audit-verifiable exact entry is available. posed_by: codex posed_date: '2026-09-14'