identifier: traitmech:000589
label: aerotaxis
definition: A motile phenotype in which active locomotion is directionally biased
  along an oxygen concentration gradient toward preferred oxygen conditions.
definition_source: DOI:10.1128/jb.178.17.5199-5204.1996
trait_category: PHYSIOLOGY
term_kind: CLASS
mapping_status: PROPOSED
parent_traits:
- METPO:1000702
evidence:
- reference: DOI:10.1128/jb.169.7.3118-3123.1987
  snippet: at high concentrations, oxygen was a repellent of Salmonella typhimurium,
    Escherichia coli, and some bacilli
  notes: Abstract, exact-matched at Europe PMC (PMID:3036771); full text not inspected.
    The study contrasts high-oxygen repulsion with attraction at lower concentrations
    and reports temporal assays. This supports concentration-dependent response direction,
    not universal thresholds or a requirement that every organism exhibit both signs.
    The abstract's tentative receptor interpretation is not promoted to an established
    mechanism.
- reference: DOI:10.1128/jb.178.17.5199-5204.1996
  snippet: As a result of aerotaxis, the bacteria were attracted to a specific low
    concentration of oxygen (3 to 5 microM).
  notes: Abstract, exact-matched at Europe PMC (PMID:8752338); full text not inspected.
    Azospirillum brasilense forms a band in a spatial oxygen gradient and returns
    when swimming into higher or lower oxygen; temporal gradients corroborate the
    response. The preferred interval is experiment-specific. Proton motive force peaks
    in the same interval, but its proposed signaling role remains a hypothesis, not
    a protein-resolved causal edge. No strain-level canonical example is inferred
    from the abstract.
- reference: DOI:10.1103/PhysRevE.106.034404
  snippet: runs in the direction of the oxygen source (x < 0) are longer and more
    frequent.
  notes: 'Section II.B, page 3; published 2022-09-15. Published full text and Appendices
    A-E read at the author''s institutional copy: https://www.fast.universite-paris-saclay.fr/~moisy/papers/2022_bouvard_pre.pdf.
    Figures 1-2 and the typeset x < 0 passage visually checked. Tracking in an oxygen-gradient
    capillary shows directional bias in Burkholderia contaminans; nonmotile cells
    are excluded with a 6 micrometre-per-second velocity threshold. The fitted response
    model does not identify a molecular receptor.'
canonical_examples:
- taxon_id: NCBITaxon:488447
  taxon_label: Burkholderia contaminans
  reference: DOI:10.1103/PhysRevE.106.034404
  note: Section II.A describes an unnamed environmental strain, identified using 16S
    and recA fragments and selected for strong aerotaxis. Figure 2 reports the motile
    subpopulation's bias toward the oxygen source. NCBI resolved 488447 on 2026-10-04
    at species rank, not as this exact isolate. This is not a universal strain or
    cell-level claim.
discussions:
- discussion_id: aerotaxis-direction-and-mapping-boundaries
  prompt: Preserve oxygen-directed scope and verify external equivalents.
  kind: CURATION_TODO
  status: OPEN
  rationale: Preferred oxygen need not be the highest available oxygen. Oxygen-dependent
    growth, respiration, tolerance and speed changes alone do not establish directional
    locomotion. Aerotaxis is narrower than general chemotaxis, while magnetic alignment
    and magnetoaerotaxis are not exact synonyms. The existing chemotaxis record is
    flagellar-specific; motile is the verified broader METPO parent without imposing
    that apparatus. No external xref or synonym is asserted before authority resolution
    and an organismal-disposition scope check.
  posed_by: codex
  posed_date: '2026-10-04'
- discussion_id: aerotaxis-mechanism-and-isolate-grounding
  prompt: Ground molecular branches and the exact environmental isolate.
  kind: CURATION_TODO
  status: OPEN
  rationale: A proton-motive-force correlation or a fitted response law does not establish
    a universal oxygen receptor or molecular pathway. Add causal graphs only after
    direct primary evidence and taxon-paired protein accessions have been verified;
    no NONMECHANISTIC graph bypasses this requirement. The canonical example lacks
    a published strain designation or accession; retain its species-level and motile-subpopulation
    qualifiers until isolate-specific identity can be resolved.
  posed_by: codex
  posed_date: '2026-10-04'
curation_history:
- timestamp: '2026-10-04T06:09:08Z'
  curator: codex
  action: MINTED_TRAITMECH_ID
  changes: Added aerotaxis with three primary DOI citations and exact snippets. Ignored-and-hidden
    searches found no exact live trait or METPO term. Reserved METPO:1054300 in v466.
    Kept attraction and repulsion within concentration-dependent directional scope,
    added a qualified NCBI-resolved environmental-isolate example, and deferred unverified
    molecular mechanisms and external mappings.
  llm_assisted: true