identifier: METPO:1000443 label: temperature optimum mid1 definition: A temperature optimum phenotype with the best-growth ambient temperature between approximately 22 and 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:1000304 synonyms: - synonym_text: Mesophilie synonym_type: EXACT_SYNONYM source: metpo.owl - synonym_text: TO_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 moderate-temperature optima matched by homoviscous lipid composition as the mesophile setpoint. causal_graphs: - graph_id: temperature_optimum_mid1_lower_mesophile title: Temperature-optimum-mid1 lower-mesophile setpoint description: DOI-backed graph linking modest membrane and enzyme adaptation at moderate ambient temperature to a temperature optimum between 22 and 27 °C. nodes: - node_id: temperature_optimum_mid1_trait label: temperature optimum mid1 node_type: TRAIT grounding: METPO:1000443 description: Temperature optimum approximately 22–27 °C. - node_id: temperature_optimum label: temperature optimum node_type: TRAIT grounding: METPO:1000304 description: Ambient temperature supporting maximal growth. - node_id: lower_mesophilic_environment label: lower-mesophilic environment node_type: ENVIRONMENTAL_FACTOR description: Habitat ambient temperature in the 22–27 °C range. - node_id: mesophile_adaptation label: mesophile membrane and enzyme adaptation node_type: BIOLOGICAL_PROCESS description: Membrane lipid composition and enzyme repertoire tuned for moderate ambient temperatures. - node_id: unsaturated_fatty_acids label: unsaturated fatty acids node_type: CHEMICAL description: Membrane fatty acids containing one or more double bonds. grounding: CHEBI:27208 - node_id: membrane_fluidity label: membrane fluidity node_type: QUALITY description: Physical fluid state of the cell membrane lipid bilayer. grounding: METPO:1007505 - node_id: homeoviscous_adaptation label: homeoviscous adaptation node_type: BIOLOGICAL_PROCESS description: Membrane lipid remodeling that maintains constant fluidity across temperatures. - node_id: low_melting_lipids label: low-melting membrane lipids node_type: CHEMICAL description: MUFAs, PUFAs, branched and short-chain fatty acids with low melting temperatures. - node_id: branched_chain_amino_acids label: branched-chain amino acids node_type: CHEMICAL description: Valine, leucine and isoleucine. - node_id: branched_chain_fatty_acids label: branched-chain fatty acids node_type: CHEMICAL description: Iso/anteiso branched membrane fatty acids derived from BCAA precursors. grounding: CHEBI:35819 edges: - subject: lower_mesophilic_environment predicate: engages object: mesophile_adaptation description: Lower-mesophilic environments engage moderate adaptation programs. evidence: - reference: DOI:10.1146/annurev-micro-091313-103612 snippet: more unsaturated fatty acids notes: Supports moderate-temperature membrane homeoviscous adaptation. - subject: mesophile_adaptation predicate: produces object: temperature_optimum_mid1_trait description: Mesophile adaptation yields a 22–27 °C optimum. evidence: - reference: DOI:10.1146/annurev-micro-091313-103612 snippet: more unsaturated fatty acids notes: Supports the 22–27 °C optimum as the lower-mesophile outcome. predicate_id: METPO:2000202 - subject: temperature_optimum_mid1_trait predicate: is a object: temperature_optimum description: Temperature optimum mid1 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 22–27 °C optimum as a value within the temperature-optimum distribution. predicate_id: rdfs:subClassOf - subject: mesophile_adaptation predicate: increases abundance of object: unsaturated_fatty_acids description: Mesophile membrane adaptation increases unsaturated fatty acid content. evidence: - reference: DOI:10.1007/s42770-023-01057-4 notes: The Des desaturase inserts double bonds in membrane fatty acids, fluidizing the membrane. - subject: unsaturated_fatty_acids predicate: increases object: membrane_fluidity description: Unsaturated fatty acids fluidize the membrane. evidence: - reference: DOI:10.1007/s42770-023-01057-4 notes: Inserting double bonds into membrane fatty acids fluidizes the membrane and reverses the cold signal. predicate_id: RO:0002213 - subject: membrane_fluidity predicate: is sensed as input to object: homeoviscous_adaptation description: Membrane physical state/fluidity is the sensed input driving homeoviscous adaptation. evidence: - reference: DOI:10.1039/d4cc03114h notes: HVA, a universal paradigm; initial step involves membrane stress sensing with membrane fluidity as a proposed sensed parameter. - subject: homeoviscous_adaptation predicate: remodels toward increased object: low_melting_lipids description: Homeoviscous adaptation increases low-melting membrane lipids. evidence: - reference: DOI:10.1039/d4cc03114h notes: 'Adaptive changes include increasing low-melting lipids: MUFAs, PUFAs, branched and short-chain fatty acids.' - subject: branched_chain_amino_acids predicate: serve as precursors for object: branched_chain_fatty_acids description: BCAAs are biosynthetic precursors of iso/anteiso branched membrane fatty acids. evidence: - reference: DOI:10.1007/s42770-023-01057-4 notes: Branched (iso/anteiso) FAs derive from branched-chain amino acid precursors (valine, leucine, isoleucine). - subject: branched_chain_fatty_acids predicate: increases object: membrane_fluidity description: Branched-chain (anteiso) fatty acids fluidize the membrane during cold adaptation. evidence: - reference: DOI:10.1007/s42770-023-01057-4 notes: Membrane fluidization via chain branching is a predominant longer-term cold adaptation mechanism. predicate_id: RO:0002213 curation_history: - timestamp: '2026-05-05T01:35:46.819857+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 mesophile membrane and enzyme adaptation to the temperature-optimum-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 (METPO:2000202×1, 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 (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 2 causal-edge predicate_id field(s) via mappings/predicate_grounding.tsv (RO:0002213×2). 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 2 causal-node grounding field(s) via mappings/node_grounding.tsv (CHEBI:27208×1, CHEBI:35819×1). llm_assisted: true