identifier: METPO:1000619 label: thermotolerant definition: A temperature preference in which growth can occur at elevated temperatures without an obligate high-temperature preference. definition_source: DOI:10.1099/00207713-52-6-2203 trait_category: ENVIRONMENT term_kind: CLASS mapping_status: REVIEWED parent_traits: - METPO:1000613 evidence: - reference: DOI:10.1099/00207713-52-6-2203 snippet: Pseudomonas thermotolerans sp. nov., a thermotolerant species notes: 'Organism example: Pseudomonas thermotolerans is described as thermotolerant.' - reference: DOI:10.1128/MMBR.65.1.1-43.2001 snippet: resistant to irreversible inactivation at high temperatures notes: Thermostable-protein review supports protein-stability features underlying facultative growth at elevated temperatures. causal_graphs: - graph_id: thermotolerant_facultative_heat_adaptation title: Thermotolerant facultative heat-adaptation mechanism description: DOI-backed graph linking thermotolerance to limited heat-stress tolerance machinery that permits growth at elevated temperatures without requiring them. nodes: - node_id: thermotolerant_trait label: thermotolerant node_type: TRAIT grounding: METPO:1000619 description: Growth at elevated temperatures without obligate high-temperature preference. - node_id: elevated_temperature label: elevated temperature node_type: ENVIRONMENTAL_FACTOR description: Ambient temperature above the mesophile optimum range. - node_id: heat_shock_response label: heat-shock response node_type: BIOLOGICAL_PROCESS description: Induction of heat-shock chaperones (GroEL, DnaK) protecting protein folding under heat stress. - node_id: chaperone_proteins label: chaperone proteins node_type: GENE_OR_PROTEIN description: Molecular chaperones refolding heat-damaged proteins. - node_id: limited_thermostability label: limited thermostability node_type: BIOLOGICAL_PROCESS description: Modest protein and membrane stability at elevated temperatures compared with obligate thermophiles. - node_id: rpoH_sigma32 label: RpoH (sigma-32) heat-shock sigma factor node_type: GENE_OR_PROTEIN description: Alternative RNA polymerase sigma factor that activates the heat-shock regulon. - node_id: heat_shock_chaperone_expression label: heat-shock chaperone gene expression node_type: BIOLOGICAL_PROCESS description: Induced expression of groEL, dnaKJ, grpE, and clpB chaperone/disaggregase genes. - node_id: rpoE_envelope_sigma label: RpoE envelope-stress sigma factor node_type: GENE_OR_PROTEIN description: Extracytoplasmic-stress sigma factor inducing periplasmic proteases and envelope-protective genes. - node_id: membrane_protein_folding_lps label: membrane protein folding and LPS biosynthesis node_type: BIOLOGICAL_PROCESS description: Folding of membrane proteins and biosynthesis of lipopolysaccharide maintaining envelope integrity under heat. - node_id: unsaturated_fa_biosynthesis label: unsaturated fatty acid biosynthesis node_type: BIOLOGICAL_PROCESS description: Biosynthesis of unsaturated fatty acids tuning membrane fluidity (homeoviscous adaptation). grounding: GO:0006636 - node_id: compatible_solute_accumulation label: trehalose compatible-solute accumulation node_type: BIOLOGICAL_PROCESS description: Accumulation of trehalose and related compatible solutes protecting proteins and membranes from heat damage. edges: - subject: elevated_temperature predicate: causes object: heat_shock_response description: Elevated temperature triggers heat-shock chaperone induction. evidence: - reference: DOI:10.1128/MMBR.65.1.1-43.2001 snippet: resistant to irreversible inactivation at high temperatures notes: Supports protein-stability physiology as a high-temperature response. predicate_id: biolink:causes - subject: chaperone_proteins predicate: enables object: limited_thermostability description: Chaperone proteins support limited thermostability sufficient for facultative high-temperature growth. evidence: - reference: DOI:10.1128/MMBR.65.1.1-43.2001 snippet: resistant to irreversible inactivation at high temperatures notes: Supports chaperone-mediated heat-stress tolerance. predicate_id: RO:0002327 - subject: limited_thermostability predicate: enables object: thermotolerant_trait description: Limited thermostability enables facultative growth at elevated temperatures. evidence: - reference: DOI:10.1099/00207713-52-6-2203 snippet: Pseudomonas thermotolerans sp. nov., a thermotolerant species notes: Supports the trait endpoint in a representative organism. predicate_id: RO:0002327 - subject: rpoH_sigma32 predicate: positively regulates object: heat_shock_chaperone_expression description: RpoH (sigma-32) drives expression of the groEL, dnaKJ, grpE, and clpB heat-shock genes. evidence: - reference: DOI:10.1186/s12934-024-02602-y notes: The expression of groEL, dnaKJ, grpE, and clpB were regulated by the sigma factor RpoH, whose deletion led to heat sensitivity. - subject: heat_shock_chaperone_expression predicate: enables object: heat_shock_response description: Induced chaperone/disaggregase gene expression enables the protective heat-shock response. evidence: - reference: DOI:10.1186/s12934-024-02602-y notes: groEL, dnaKJ, grpE, clpB constitute the chaperone/disaggregase machinery of the heat-shock response. predicate_id: RO:0002327 - subject: elevated_temperature predicate: causes object: membrane_protein_folding_lps description: Heat-activated RpoE induces membrane protein folding and LPS biosynthesis to preserve envelope integrity. evidence: - reference: DOI:10.1007/s12275-023-00031-x notes: Activated RpoE induces genes involved in folding of membrane proteins and biosynthesis of lipopolysaccharides under heat shock. predicate_id: biolink:causes - subject: rpoE_envelope_sigma predicate: positively regulates object: membrane_protein_folding_lps description: RpoE envelope-stress sigma factor positively regulates membrane protein folding and LPS biosynthesis. evidence: - reference: DOI:10.1007/s12275-023-00031-x notes: Activated RpoE induces heat-shock proteins, periplasmic proteases (HtrA, DegP), and genes for membrane protein folding and LPS biosynthesis. - subject: unsaturated_fa_biosynthesis predicate: contributes to object: thermotolerant_trait description: Unsaturated fatty acid biosynthesis tunes membrane fluidity, contributing to thermotolerance. evidence: - reference: DOI:10.1128/spectrum.01627-23 notes: A sharp relationship between thermotolerance and fatty-acid metabolism; saturated/unsaturated FA balance modulates heat tolerance. predicate_id: RO:0002326 - subject: compatible_solute_accumulation predicate: positively regulates object: limited_thermostability description: Trehalose compatible-solute accumulation stabilizes proteins and membranes against heat damage. evidence: - reference: DOI:10.1186/s40694-023-00168-9 notes: Accumulation of mannitol and trehalose as the main compatible solutes is a key factor for heat resistance. curation_history: - timestamp: '2026-05-05T01:35:46.860266+00:00' curator: seed_from_metpo action: SEEDED_FROM_METPO changes: imported from data/raw/metpo.owl (CLASS) llm_assisted: false - timestamp: '2026-05-06T14:58:45-07:00' curator: codex action: CURATED_WITH_ORGANISM_EXAMPLE changes: Added Pseudomonas thermotolerans organism example with PMID-backed evidence. llm_assisted: true - timestamp: '2026-05-13T11:30:00-07:00' curator: claude action: CURATED_CAUSAL_GRAPH changes: Added DOI-backed causal graph linking heat-shock response, chaperone proteins, and limited thermostability to the thermotolerant trait. llm_assisted: true - timestamp: '2026-05-13T22:45:00-07:00' curator: codex action: IMPROVED_CAUSAL_GRAPH_EVIDENCE changes: Replaced Pseudomonas thermotolerans PMID fallback with the article DOI in definition, record evidence, and CausalEdge evidence. llm_assisted: true - timestamp: '2026-05-20T03:35:30Z' curator: claude action: GROUND_CAUSAL_PREDICATES changes: Grounded 1 causal-edge predicate_id field(s) via mappings/predicate_grounding.tsv (RO:0002327×1). llm_assisted: true - timestamp: '2026-05-24T04:13:18Z' curator: claude action: RENAME_PREDICATE_LABELS changes: 'Renamed 1 causal-edge predicate label(s) to align with existing groundings: supports → enables ×1.' llm_assisted: true - timestamp: '2026-05-24T04:13:21Z' curator: claude action: GROUND_CAUSAL_PREDICATES changes: Grounded 1 causal-edge predicate_id field(s) via mappings/predicate_grounding.tsv (RO:0002327×1). llm_assisted: true - timestamp: '2026-05-26T05:00:47Z' curator: claude action: RENAME_PREDICATE_LABELS changes: 'Renamed 1 causal-edge predicate label(s) to align with existing groundings: triggers → causes ×1.' llm_assisted: true - timestamp: '2026-05-26T05:00:50Z' curator: claude action: GROUND_CAUSAL_PREDICATES changes: Grounded 1 causal-edge predicate_id field(s) via mappings/predicate_grounding.tsv (biolink:causes×1). llm_assisted: true - timestamp: '2026-06-17T04:09:43Z' curator: claude action: REMOVE_REDUNDANT_SYNONYM changes: Removed 1 synonym(s) whose text duplicated the label (seeder redundancy; no information lost). llm_assisted: true - timestamp: '2026-06-23T00:00:00Z' curator: claude action: ENRICH_CAUSAL_GRAPH changes: Added 6 evidence-backed generic edges (6 new nodes) from the deep-research report. llm_assisted: true - timestamp: '2026-06-24T17:21:11Z' curator: claude action: GROUND_CAUSAL_PREDICATES changes: Grounded 3 causal-edge predicate_id field(s) via mappings/predicate_grounding.tsv (RO:0002327×1, biolink:causes×1, RO:0002326×1). llm_assisted: true - timestamp: '2026-06-24T17:23:32Z' curator: claude action: GROUND_CAUSAL_NODES changes: Grounded 1 causal-node grounding field(s) via mappings/node_grounding.tsv (GO:0006636×1). llm_assisted: true