identifier: METPO:1000450 label: temperature range mid1 definition: A temperature range phenotype in which the growth-supporting ambient temperature range spans approximately 22–27 °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:1000306 synonyms: - synonym_text: Mesophilie synonym_type: EXACT_SYNONYM source: metpo.owl - synonym_text: TR_22_to_27 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 22–27 °C range as a lower mesophile growth range. causal_graphs: - graph_id: temperature_range_mid1_lower_mesophile title: Temperature-range-mid1 lower-mesophile range description: DOI-backed graph linking lower-mesophile adaptation to a temperature growth range of approximately 22–27 °C. nodes: - node_id: temperature_range_mid1_trait label: temperature range mid1 node_type: TRAIT grounding: METPO:1000450 description: Temperature growth-supporting range approximately 22–27 °C. - node_id: temperature_range label: temperature range node_type: TRAIT grounding: METPO:1000306 description: Span of ambient temperatures supporting growth. - node_id: lower_mesophile_adaptation label: lower-mesophile adaptation node_type: BIOLOGICAL_PROCESS description: Mesophile membrane and enzyme adaptation sustaining growth at modest ambient temperatures. - node_id: temperature_decrease label: temperature decrease node_type: ENVIRONMENTAL_FACTOR description: A drop in ambient growth temperature within or toward the mesophilic range. - node_id: membrane_rigidification label: membrane rigidification/thickening node_type: QUALITY description: Cooling-induced reduction of membrane fluidity and increased bilayer thickness. - node_id: fatty_acid_desaturation label: fatty-acid desaturation node_type: BIOLOGICAL_PROCESS description: Introduction of double bonds into membrane fatty acyl chains. - node_id: membrane_fluidity label: membrane fluidity node_type: QUALITY description: Physical fluidity/viscosity state of the cell membrane lipid bilayer. grounding: METPO:1007505 - node_id: branched_chain_amino_acids label: branched-chain amino acids node_type: CHEMICAL description: Valine, leucine and isoleucine serving as precursors for branched-chain fatty acids. - node_id: anteiso_branched_fatty_acids label: anteiso-branched fatty acids node_type: CHEMICAL description: Anteiso-branched-chain fatty acids that disorder membrane lipids. - node_id: rna_thermometer_melting label: RNA thermometer melting node_type: MOLECULAR_FUNCTION description: Temperature-dependent unfolding of 5-prime-UTR cis-elements controlling translation. - node_id: shine_dalgarno_exposure label: Shine-Dalgarno sequence exposure node_type: MOLECULAR_FUNCTION description: Exposure of the ribosome-binding Shine-Dalgarno sequence enabling translation. - node_id: temperature_shift label: temperature shift node_type: ENVIRONMENTAL_FACTOR description: A change in ambient growth temperature. - node_id: dna_supercoiling label: DNA supercoiling node_type: QUALITY description: DNA topological state acting as a thermosensor that reprograms transcription. edges: - subject: lower_mesophile_adaptation predicate: enables object: temperature_range_mid1_trait description: Lower-mesophile adaptation enables growth across 22–27 °C. evidence: - reference: DOI:10.1146/annurev-micro-091313-103612 snippet: more unsaturated fatty acids notes: Supports homoviscous mesophile adaptation as the lower-mesophile range mechanism. predicate_id: RO:0002327 - subject: temperature_range_mid1_trait predicate: is a object: temperature_range description: Temperature range mid1 is a quantitative bin of the temperature-range phenotype. evidence: - reference: DOI:10.1016/s0300-9629(97)00003-0 snippet: adapted to environments of high temperature notes: Supports the 22–27 °C range as a value within the temperature-range distribution. predicate_id: rdfs:subClassOf - subject: temperature_decrease predicate: causes object: membrane_rigidification description: Cooling reduces membrane fluidity and increases bilayer thickness, the initiating physical signal for adaptation. evidence: - reference: DOI:10.1007/s42770-023-01057-4 notes: Membrane rigidification and increased thickness act as the primary physical signal upon cooling. predicate_id: biolink:causes - subject: fatty_acid_desaturation predicate: increases object: membrane_fluidity description: Double bonds disrupt tight acyl-chain packing, reversing cold-induced rigidification. evidence: - reference: DOI:10.1128/spectrum.03925-23 notes: Desaturation fluidizes the membrane and reduces thickness; strong and broadly conserved principle. predicate_id: RO:0002213 - subject: anteiso_branched_fatty_acids predicate: increases object: membrane_fluidity description: Anteiso chains disorder lipids effectively, supporting growth at lower temperatures. evidence: - reference: DOI:10.3390/cells12101353 notes: Anteiso-BCFAs are more effective at fluidizing membranes than iso-BCFAs; generalizable across many Gram-positives. predicate_id: RO:0002213 - subject: branched_chain_amino_acids predicate: precursor for object: anteiso_branched_fatty_acids description: Branched-chain amino acids supply carbon skeletons for iso/anteiso-branched fatty acid synthesis. evidence: - reference: DOI:10.1007/s42770-023-01057-4 notes: Iso- and anteiso-branched FAs are derived from valine, leucine, and isoleucine precursors. - subject: rna_thermometer_melting predicate: exposes object: shine_dalgarno_exposure description: Temperature-dependent melting of RNA thermometers exposes the Shine-Dalgarno sequence to control translation. evidence: - reference: DOI:10.1007/s12275-023-00031-x notes: 5'-UTR cis-elements occlude or expose Shine-Dalgarno sequences to control translation; strong general mechanism. - subject: temperature_shift predicate: changes object: dna_supercoiling description: DNA topology functions as a thermosensor that globally reprograms transcription after temperature change. evidence: - reference: DOI:10.1007/s12275-023-00031-x notes: DNA topology acts as a thermosensor; cold stress enhances negative DNA supercoiling. curation_history: - timestamp: '2026-05-05T01:35:46.823745+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 lower-mesophile adaptation to the temperature-range-mid1 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 (RO:0002327×1, rdfs:subClassOf×1). llm_assisted: true - timestamp: '2026-06-23T00:00:00Z' curator: claude action: ENRICH_CAUSAL_GRAPH changes: Added 6 evidence-backed generic edges (10 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:0002213×2, biolink:causes×1). llm_assisted: true - timestamp: '2026-06-24T17:21:18Z' 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