identifier: METPO:1005001
label: nitrification
definition: A biological process in which ammonia is oxidized to nitrite (ammonia
  oxidation) and nitrite is oxidized to nitrate (nitrite oxidation), in two steps.
trait_category: METABOLISM
term_kind: CLASS
mapping_status: SEEDED
parent_traits:
- METPO:1000630
curation_history:
- timestamp: '2026-09-11T06:15:37Z'
  curator: seed_from_metpo
  action: SEEDED_FROM_METPO
  changes: imported from data/raw/metpo.owl (CLASS)
- timestamp: '2026-09-11T06:20:00Z'
  curator: codex
  action: ENRICHED_FROM_LITERATURE
  changes: Enriched the active METPO nitrification class with DOI-backed two-step
    ammonia- and nitrite-oxidation evidence after a repository-wide duplicate review
    covering ignored and hidden files.
  llm_assisted: true
definition_source: DOI:10.3389/fmicb.2020.01900
evidence:
- reference: DOI:10.3389/fmicb.2020.01900
  snippet: nitrification proceeds as a two-step process, involving the oxidation of
    ammonia to nitrite and the oxidation of nitrite to nitrate
  notes: Sedlacek et al. review the historical evidence that established nitrification
    as a microbially mediated, two-step ammonia- and nitrite-oxidation process.
discussions:
- discussion_id: nitrification-component-go-xref-gap
  prompt: Resolve an exact external ontology class for the complete nitrification
    process before adding a TraitRecord xref.
  kind: CURATION_TODO
  status: OPEN
  rationale: METPO cites GO:0019329 ammonia oxidation and GO:0019332 nitrite oxidation
    as definition components, but each GO term covers only one half of the full two-step
    nitrification trait and is not exact enough for TraitRecord xrefs.
  posed_by: codex
  posed_date: '2026-09-11'