identifier: METPO:1000445
label: temperature optimum mid3
definition: A temperature optimum phenotype with the best-growth ambient temperature
  between approximately 30 and 34 °C, characteristic of mesophilic physiology.
definition_source: DOI:10.1146/annurev-micro-091313-103612
trait_category: ENVIRONMENT
term_kind: CLASS
mapping_status: REVIEWED
parent_traits:
- METPO:1000304
synonyms:
- synonym_text: Mesophilie
  synonym_type: EXACT_SYNONYM
  source: metpo.owl
- synonym_text: TO_30_to_34
  synonym_type: RELATED_SYNONYM
  source: metpo.owl
evidence:
- reference: DOI:10.1146/annurev-micro-091313-103612
  snippet: more unsaturated fatty acids
  notes: Membrane-adaptation review supports the 30–34 °C optimum as a typical mesophile
    setpoint near common host body temperatures.
causal_graphs:
- graph_id: temperature_optimum_mid3_upper_mesophile
  title: Temperature-optimum-mid3 upper-mesophile setpoint
  description: DOI-backed graph linking upper-mesophile membrane and enzyme adaptation
    to a temperature optimum between 30 and 34 °C.
  nodes:
  - node_id: temperature_optimum_mid3_trait
    label: temperature optimum mid3
    node_type: TRAIT
    grounding: METPO:1000445
    description: Temperature optimum approximately 30–34 °C.
  - node_id: temperature_optimum
    label: temperature optimum
    node_type: TRAIT
    grounding: METPO:1000304
    description: Ambient temperature supporting maximal growth.
  - node_id: upper_mesophilic_environment
    label: upper-mesophilic environment
    node_type: ENVIRONMENTAL_FACTOR
    description: Habitat ambient temperature in the 30–34 °C range.
  - node_id: upper_mesophile_adaptation
    label: upper-mesophile adaptation
    node_type: BIOLOGICAL_PROCESS
    description: Membrane lipid composition and enzyme repertoire tuned for ambient
      temperatures near common animal host body temperatures.
  - node_id: decreased_temperature
    label: decreased temperature
    node_type: ENVIRONMENTAL_FACTOR
    description: A drop in ambient temperature toward the lower mesophilic range.
    grounding: PATO:0001306
  - node_id: membrane_bilayer
    label: membrane bilayer
    node_type: CELLULAR_LOCALIZATION
    description: The lipid bilayer of the cell membrane whose physical state depends
      on temperature.
  - node_id: homeoviscous_adaptation
    label: homeoviscous adaptation
    node_type: BIOLOGICAL_PROCESS
    description: Lipid remodeling that maintains membrane fluidity across temperatures.
  - node_id: liquid_crystalline_membrane_state
    label: liquid-crystalline membrane state
    node_type: STATE
    description: Fluid, functional physical state of the membrane bilayer supporting
      growth.
  - node_id: mufa_incorporation
    label: monounsaturated fatty acid incorporation
    node_type: BIOLOGICAL_PROCESS
    description: Incorporation of cis-monounsaturated fatty acids into membrane lipids.
  - node_id: membrane_fluidity
    label: membrane fluidity
    node_type: QUALITY
    description: Degree of fluidity/disorder of the membrane lipid bilayer.
    grounding: METPO:1007505
  - node_id: chaperone_network
    label: molecular chaperone network
    node_type: GENE_OR_PROTEIN
    description: DnaK/DnaJ, GroEL/GroES, ClpB, HtpG chaperone system.
  - node_id: proteostasis
    label: proteostasis
    node_type: BIOLOGICAL_PROCESS
    description: Maintenance of protein folding homeostasis during temperature shifts.
  edges:
  - subject: upper_mesophilic_environment
    predicate: engages
    object: upper_mesophile_adaptation
    description: Upper-mesophilic environments engage upper-mesophile adaptation.
    evidence:
    - reference: DOI:10.1146/annurev-micro-091313-103612
      snippet: more unsaturated fatty acids
      notes: Supports homoviscous adaptation at upper-mesophilic temperatures.
  - subject: upper_mesophile_adaptation
    predicate: produces
    object: temperature_optimum_mid3_trait
    description: Upper-mesophile adaptation yields a 30–34 °C optimum.
    evidence:
    - reference: DOI:10.1146/annurev-micro-091313-103612
      snippet: more unsaturated fatty acids
      notes: Supports the 30–34 °C optimum as the upper-mesophile outcome.
    predicate_id: METPO:2000202
  - subject: temperature_optimum_mid3_trait
    predicate: is a
    object: temperature_optimum
    description: Temperature optimum mid3 is a quantitative bin of the temperature-optimum
      phenotype.
    evidence:
    - reference: DOI:10.1016/s0300-9629(97)00003-0
      snippet: adapted to environments of high temperature
      notes: Supports the 30–34 °C optimum as a value within the temperature-optimum
        distribution.
    predicate_id: rdfs:subClassOf
  - subject: decreased_temperature
    predicate: rigidifies
    object: membrane_bilayer
    description: Cooler conditions rigidify and thicken the membrane bilayer, triggering
      fluidity-restoring responses.
    evidence:
    - reference: DOI:10.1128/spectrum.03925-23
      notes: 'Core homeoviscous trigger: "upon temperature decrease the membrane rigidifies
        and thickens."'
  - subject: homeoviscous_adaptation
    predicate: restores
    object: liquid_crystalline_membrane_state
    description: Homeoviscous adaptation restores the fluid, liquid-crystalline membrane
      state across mesophilic temperatures.
    evidence:
    - reference: DOI:10.1007/s42770-023-01057-4
      notes: 'General process-level support: "These changes are often referred to
        as homeoviscous adaptation."'
  - subject: mufa_incorporation
    predicate: increases
    object: membrane_fluidity
    description: Incorporation of cis-monounsaturated fatty acids increases membrane
      fluidity at lower temperatures.
    evidence:
    - reference: DOI:10.1007/s42770-023-01057-4
      notes: '"The most common adaptation is the incorporation of monounsaturated
        fatty acids (MUFA), preferably cis-unsaturated ones."'
    predicate_id: RO:0002213
  - subject: chaperone_network
    predicate: maintains
    object: proteostasis
    description: The chaperone network prevents and resolves aggregates, maintaining
      proteostasis during temperature shifts.
    evidence:
    - reference: DOI:10.1007/s12275-023-00031-x
      notes: 'General proteostasis module: "DnaK-DnaJ, GroEL-GroES, HtpG, ClpB" prevent/resolve
        aggregates.'
curation_history:
- timestamp: '2026-05-05T01:35:46.820979+00:00'
  curator: seed_from_metpo
  action: SEEDED_FROM_METPO
  changes: imported from data/raw/metpo.owl (CLASS)
  llm_assisted: false
- timestamp: '2026-05-13T11:00:00-07:00'
  curator: claude
  action: CURATED_CAUSAL_GRAPH
  changes: Added DOI-backed definition and causal graph linking upper-mesophile adaptation
    to the temperature-optimum-mid3 bin.
  llm_assisted: true
- timestamp: '2026-05-20T03:35:30Z'
  curator: claude
  action: GROUND_CAUSAL_PREDICATES
  changes: Grounded 2 causal-edge predicate_id field(s) via mappings/predicate_grounding.tsv
    (METPO:2000202×1, rdfs:subClassOf×1).
  llm_assisted: true
- timestamp: '2026-06-23T00:00:00Z'
  curator: claude
  action: ENRICH_CAUSAL_GRAPH
  changes: Added 4 evidence-backed generic edges (8 new nodes) from the deep-research
    report.
  llm_assisted: true
- timestamp: '2026-06-24T17:21:11Z'
  curator: claude
  action: GROUND_CAUSAL_PREDICATES
  changes: Grounded 1 causal-edge predicate_id field(s) via mappings/predicate_grounding.tsv
    (RO:0002213×1).
  llm_assisted: true
- timestamp: '2026-06-24T17:21:17Z'
  curator: claude
  action: GROUND_CAUSAL_NODES
  changes: Grounded 1 causal-node grounding field(s) via mappings/node_grounding.tsv
    (METPO:1007505×1).
  llm_assisted: true
- timestamp: '2026-06-24T17:23:31Z'
  curator: claude
  action: GROUND_CAUSAL_NODES
  changes: Grounded 1 causal-node grounding field(s) via mappings/node_grounding.tsv
    (PATO:0001306×1).
  llm_assisted: true