identifier: traitmech:000075
label: catalase activity
definition: A physiological enzyme-activity phenotype in which a cell produces catalase,
  which decomposes hydrogen peroxide into water and oxygen; it is the basis of the
  diagnostic catalase test.
definition_source: DOI:10.1007/s00018-003-3206-5
trait_category: PHYSIOLOGY
term_kind: CLASS
mapping_status: REVIEWED
parent_traits:
- METPO:1000059
synonyms:
- synonym_text: catalase-positive
  synonym_type: RELATED_SYNONYM
  source: DOI:10.1007/s00018-003-3206-5
evidence:
- reference: DOI:10.1007/s00018-003-3206-5
  notes: Chelikani, Fita & Loewen review the diversity of catalases, enzymes that
    dismutate hydrogen peroxide to water and oxygen.
- reference: DOI:10.1038/nrmicro3032
  notes: Imlay's oxidative-stress review supports catalase as a key hydrogen-peroxide
    scavenging defense.
canonical_examples:
- taxon_id: NCBITaxon:1280
  taxon_label: Staphylococcus aureus
  note: "catalase-positive"
  reference: PMID:17114262
- taxon_id: NCBITaxon:287
  taxon_label: Pseudomonas aeruginosa
  note: "catalase-positive"
  reference: PMID:15972537
causal_graphs:
- graph_id: catalase_activity_h2o2_detoxification
  title: Catalase hydrogen-peroxide detoxification
  description: Evidence-backed causal sketch linking catalase to dismutation of hydrogen
    peroxide into water and molecular oxygen.
  nodes:
  - node_id: catalase_activity_trait
    label: catalase activity
    node_type: TRAIT
    grounding: traitmech:000075
    description: Capacity to decompose hydrogen peroxide via catalase.
  - node_id: catalase
    label: catalase
    node_type: GENE_OR_PROTEIN
    description: Heme enzyme that dismutates hydrogen peroxide.
    grounding: UniProtKB:A0A071MK53
  - node_id: catalase_function
    label: catalase activity
    node_type: MOLECULAR_FUNCTION
    grounding: GO:0004096
    description: Catalysis of 2 H2O2 = O2 + 2 H2O.
  - node_id: hydrogen_peroxide
    label: hydrogen peroxide
    node_type: CHEMICAL
    grounding: CHEBI:16240
    description: Reactive oxygen species detoxified by catalase.
  - node_id: molecular_oxygen
    label: molecular oxygen
    node_type: CHEMICAL
    grounding: CHEBI:15379
    description: Product of hydrogen peroxide dismutation.
  - node_id: water
    label: water
    node_type: CHEMICAL
    grounding: CHEBI:15377
    description: Product of hydrogen peroxide dismutation.
  - node_id: oxyr_regulator
    label: OxyR
    node_type: GENE_OR_PROTEIN
    description: Peroxide-sensing transcriptional regulator activated by hydrogen
      peroxide.
    grounding: UniProtKB:A0A9P2M4N5
  - node_id: perr_regulator
    label: PerR
    node_type: GENE_OR_PROTEIN
    description: Fe-dependent peroxide-sensing transcriptional repressor inactivated
      by hydrogen peroxide.
    grounding: UniProtKB:A0A097ASJ8
  - node_id: peroxide_defense_systems
    label: peroxide defense systems
    node_type: BIOLOGICAL_PROCESS
    description: Antioxidant defense systems (e.g. catalases, peroxidases) that detoxify
      hydrogen peroxide.
  - node_id: heme_biosynthesis
    label: heme biosynthesis
    node_type: BIOLOGICAL_PROCESS
    description: Synthesis of the heme cofactor required for catalase maturation and
      activity.
    grounding: GO:0006783
  edges:
  - subject: catalase
    predicate: enables
    object: catalase_function
    description: Catalase carries out the catalase molecular function.
    evidence:
    - reference: DOI:10.1007/s00018-003-3206-5
      notes: Chelikani et al. characterize catalases as the enzymes performing this
        dismutation.
    predicate_id: RO:0002327
  - subject: catalase_function
    predicate: consumes
    object: hydrogen_peroxide
    description: The catalase reaction consumes hydrogen peroxide.
    evidence:
    - reference: DOI:10.1038/nrmicro3032
      notes: Imlay supports catalase as a primary hydrogen-peroxide scavenging defense.
    predicate_id: biolink:consumes
  - subject: catalase_function
    predicate: produces
    object: molecular_oxygen
    description: The catalase reaction produces molecular oxygen.
    evidence:
    - reference: DOI:10.1007/s00018-003-3206-5
      notes: Catalase dismutation yields O2 (2 H2O2 to O2 + 2 H2O).
    predicate_id: METPO:2000202
  - subject: catalase_function
    predicate: produces
    object: water
    description: The catalase reaction produces water.
    evidence:
    - reference: DOI:10.1007/s00018-003-3206-5
      notes: Catalase dismutation yields water.
    predicate_id: METPO:2000202
  - subject: catalase
    predicate: enables
    object: catalase_activity_trait
    description: Production of catalase confers the catalase-activity phenotype.
    evidence:
    - reference: DOI:10.1007/s00018-003-3206-5
      notes: Supports catalase possession as the basis of the catalase-activity phenotype.
    predicate_id: RO:0002327
  - subject: catalase_activity_trait
    predicate: decomposes
    object: hydrogen_peroxide
    description: Catalase activity rapidly decomposes hydrogen peroxide into water
      and molecular oxygen.
    evidence:
    - reference: DOI:10.3390/biom14060697
      notes: Catalase rapidly decomposes hydrogen peroxide into water and molecular
        oxygen (canonical enzymology).
  - subject: hydrogen_peroxide
    predicate: activates
    object: oxyr_regulator
    description: Hydrogen peroxide activates the OxyR peroxide-sensing regulator.
    evidence:
    - reference: DOI:10.1038/nrmicro3032
      notes: An intracellular H2O2 concentration of ~200 nM is sufficient to drive
        OxyR into a disulfide-bonded (active) form.
    predicate_id: RO:0002213
  - subject: hydrogen_peroxide
    predicate: favors scavenging by
    object: catalase_activity_trait
    description: High hydrogen peroxide concentrations favor scavenging by catalases,
      which turn over much faster than alkyl hydroperoxide reductase.
    evidence:
    - reference: DOI:10.1038/nrmicro3032
      notes: Organisms rely on catalases when H2O2 levels are high; catalases turn
        over much more quickly than Ahp. Likely general across aerobes/facultative
        anaerobes.
  - subject: oxyr_regulator
    predicate: regulates
    object: peroxide_defense_systems
    description: OxyR regulates peroxide defense systems; most bacteria sense H2O2
      via OxyR or PerR.
    evidence:
    - reference: DOI:10.3389/fimmu.2021.667343
      notes: Most bacteria sense H2O2 via OxyR or PerR transcription factors that
        control peroxide defense systems.
    predicate_id: RO:0002211
  - subject: perr_regulator
    predicate: regulates
    object: peroxide_defense_systems
    description: PerR regulates peroxide defense systems; most bacteria sense H2O2
      via OxyR or PerR.
    evidence:
    - reference: DOI:10.3389/fimmu.2021.667343
      notes: Most bacteria sense H2O2 via OxyR or PerR transcription factors that
        control peroxide defense systems.
    predicate_id: RO:0002211
  - subject: heme_biosynthesis
    predicate: required for
    object: catalase
    description: Heme biosynthesis is required for catalase activation; impaired heme
      synthesis delays peroxide degradation.
    evidence:
    - reference: DOI:10.1111/mmi.12967
      notes: Ferrochelatase (hemH) function is required for timely induction of catalase
        (KatG) activity; loss delays H2O2 degradation and growth.
curation_history:
- timestamp: '2026-06-04T00:00:00Z'
  curator: claude
  action: PROPOSED_FROM_RESEARCH
  changes: Proposed candidate PHYSIOLOGY trait (catalase activity) from literature
    research to fill the enzyme-activity-phenotype gap.
  llm_assisted: true
- timestamp: '2026-06-08T00:00:00Z'
  curator: claude
  action: CURATED_CAUSAL_GRAPH
  changes: Added evidence-backed causal graph (catalase hydrogen-peroxide dismutation)
    with CHEBI/GO node groundings and RO/METPO/biolink predicate groundings; promoted
    PROPOSED to REVIEWED.
  llm_assisted: true
- timestamp: '2026-06-14T06:38:15Z'
  curator: claude
  action: GROUND_CAUSAL_NODES
  changes: Grounded 1 causal-node grounding field(s) via mappings/node_grounding.tsv
    (UniProtKB:A0A071MK53×1).
  llm_assisted: true
- timestamp: '2026-06-23T00:00:00Z'
  curator: claude
  action: ENRICH_CAUSAL_GRAPH
  changes: Added 6 evidence-backed generic edges (4 new nodes) from the deep-research
    report.
  llm_assisted: true
- timestamp: '2026-06-24T17:21:14Z'
  curator: claude
  action: GROUND_CAUSAL_PREDICATES
  changes: Grounded 3 causal-edge predicate_id field(s) via mappings/predicate_grounding.tsv
    (RO:0002211×2, RO:0002213×1).
  llm_assisted: true
- timestamp: '2026-06-24T17:23:34Z'
  curator: claude
  action: GROUND_CAUSAL_NODES
  changes: Grounded 1 causal-node grounding field(s) via mappings/node_grounding.tsv
    (GO:0006783×1).
  llm_assisted: true
- timestamp: '2026-06-26T07:15:20Z'
  curator: claude
  action: GROUND_CAUSAL_NODES
  changes: Grounded 2 causal-node grounding field(s) via mappings/node_grounding.tsv
    (UniProtKB:A0A9P2M4N5×1, UniProtKB:A0A097ASJ8×1).
  llm_assisted: true