identifier: METPO:1000480 label: NaCl delta mid1 definition: A NaCl delta phenotype with a growth-supporting NaCl breadth of approximately 1–3% (w/v), characteristic of organisms with modest salinity tolerance breadth. definition_source: DOI:10.1093/femsre/fuy009 trait_category: ENVIRONMENT term_kind: CLASS mapping_status: REVIEWED parent_traits: - METPO:1000335 synonyms: - synonym_text: Nad_1_3 synonym_type: RELATED_SYNONYM source: metpo.owl evidence: - reference: DOI:10.1093/femsre/fuy009 snippet: salinity range notes: Osmoadaptation review supports intermediate breadths as common among osmoadaptive bacteria. causal_graphs: - graph_id: nacl_delta_mid1_modest_breadth title: NaCl-delta-mid1 modest-breadth osmoadaptation description: DOI-backed graph linking modest osmoadaptive flexibility to a 1–3% (w/v) NaCl growth breadth. nodes: - node_id: nacl_delta_mid1_trait label: NaCl delta mid1 node_type: TRAIT grounding: METPO:1000480 description: NaCl growth-supporting breadth approximately 1–3% w/v. - node_id: nacl_delta label: NaCl delta node_type: TRAIT grounding: METPO:1000335 description: Breadth of the growth-supporting NaCl range. - node_id: modest_osmoadaptive_flexibility label: modest osmoadaptive flexibility node_type: BIOLOGICAL_PROCESS description: Moderate capacity to remodel osmolytes across ambient salinity shifts. - node_id: osmotic_upshift label: osmotic upshift node_type: ENVIRONMENTAL_FACTOR description: Sudden increase in external osmolarity (e.g. NaCl) imposing hyperosmotic stress. - node_id: k_import label: potassium import node_type: BIOLOGICAL_PROCESS description: Rapid cytoplasmic accumulation of K+ as a first-line osmoadaptive response. grounding: GO:1990573 - node_id: compatible_solute_accumulation label: compatible solute accumulation node_type: BIOLOGICAL_PROCESS description: Accumulation/synthesis of neutral organic osmolytes (glycine betaine, proline, trehalose, ectoine, carnitine). - node_id: osmoadaptation_under_nacl label: osmoadaptation / growth under NaCl stress node_type: BIOLOGICAL_PROCESS description: Maintenance of turgor, protein and membrane stability, and growth across NaCl stress. - node_id: ectoine_biosynthesis label: ectoine biosynthesis (EctB/EctA/EctC) node_type: PATHWAY description: Three-enzyme biosynthetic pathway producing the compatible solute ectoine. - node_id: ectoine label: ectoine node_type: CHEMICAL description: Compatible solute (CHEBI:22586) contributing to salt tolerance. grounding: CHEBI:27592 - node_id: c_di_amp label: cyclic di-AMP node_type: CHEMICAL description: Second messenger (CHEBI:167606) central to osmoregulation of K+ and osmolyte economy. grounding: CHEBI:71578 - node_id: organic_osmolyte_influx_biosynthesis label: compatible organic osmolyte influx and biosynthesis node_type: BIOLOGICAL_PROCESS description: Influx and biosynthesis of physiologically compatible organic osmolytes. edges: - subject: modest_osmoadaptive_flexibility predicate: produces object: nacl_delta_mid1_trait description: Modest osmoadaptive flexibility yields a 1–3% NaCl-delta breadth. evidence: - reference: DOI:10.1093/femsre/fuy009 snippet: salinity range notes: Supports modest osmoadaptive flexibility as the basis of an intermediate breadth. predicate_id: METPO:2000202 - subject: nacl_delta_mid1_trait predicate: is a object: nacl_delta description: NaCl delta mid1 is a quantitative bin of the NaCl-delta phenotype. evidence: - reference: DOI:10.1093/femsre/fuy009 snippet: salinity range notes: Supports the 1–3% breadth as a value within the NaCl-delta distribution. predicate_id: rdfs:subClassOf - subject: osmotic_upshift predicate: induces object: k_import description: Hyperosmotic upshift triggers rapid K+ import to raise cytoplasmic osmolarity/turgor. evidence: - reference: DOI:10.1128/MMBR.00181-23 notes: Bacterial cells commonly import a lot of potassium during an osmotic upshift (broad bacterial relevance). - subject: k_import predicate: precedes/replaced by object: compatible_solute_accumulation description: Initial K+ accumulation is subsequently replaced by neutral compatible solutes to reduce ionic stress. evidence: - reference: DOI:10.1128/MMBR.00181-23 notes: Cells begin accumulating/synthesizing neutral compatible solutes such as glycine betaine, trehalose, and other osmolytes to replace K+ ions. - subject: osmotic_upshift predicate: induces object: compatible_solute_accumulation description: Osmoadaptation transitions from inorganic K+ accumulation to organic osmoprotectants. evidence: - reference: DOI:10.3389/fmicb.2019.02811 notes: Cells initially accumulate potassium as an emergency stress reaction and subsequently replace most of this ion with compatible solutes. - subject: compatible_solute_accumulation predicate: supports object: osmoadaptation_under_nacl description: Organic osmolytes stabilize proteins/membranes and raise intracellular osmotic strength without salt-in toxicity. evidence: - reference: DOI:10.1093/femsre/fuaf020 notes: Bacteria commonly use compatible solutes - notably glycine betaine, proline, trehalose, ectoine and carnitine - to support osmoadaptation. - subject: ectoine_biosynthesis predicate: produces object: ectoine description: The EctB/EctA/EctC pathway synthesizes the compatible solute ectoine. evidence: - reference: DOI:10.3389/fmicb.2019.02811 notes: Ectoine biosynthesis is mediated by three enzymes (EctB, EctA, EctC). predicate_id: METPO:2000202 - subject: ectoine predicate: contributes to object: compatible_solute_accumulation description: Ectoine is one of the compatible solutes accumulated during osmoadaptation. evidence: - reference: DOI:10.1093/femsre/fuaf020 notes: Ectoine is among the compatible solutes bacteria commonly use for osmoprotection. predicate_id: RO:0002326 - subject: c_di_amp predicate: decreases object: k_import description: Elevated c-di-AMP downregulates osmoregulatory K+ import. evidence: - reference: DOI:10.1128/MMBR.00181-23 notes: High cyclic di-AMP reduces K+ import (review-level regulatory edge). predicate_id: RO:0002212 - subject: c_di_amp predicate: controls object: organic_osmolyte_influx_biosynthesis description: c-di-AMP regulates both the influx of compatible organic osmolytes and their biosynthesis. evidence: - reference: DOI:10.1128/JB.00190-24 notes: c-di-AMP plays a key role by controlling (i) the influx of physiologically compatible organic osmolytes and (ii) the biosynthesis of such osmolytes. predicate_id: RO:0002211 curation_history: - timestamp: '2026-05-05T01:35:46.841250+00:00' curator: seed_from_metpo action: SEEDED_FROM_METPO changes: imported from data/raw/metpo.owl (CLASS) llm_assisted: false - timestamp: '2026-05-12T10:00:00-07:00' curator: claude action: CURATED_CAUSAL_GRAPH changes: Added DOI-backed definition and causal graph linking modest osmoadaptive flexibility to the intermediate-breadth NaCl-delta 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 8 evidence-backed generic edges (8 new nodes) from the deep-research report. llm_assisted: true - timestamp: '2026-06-24T17:21:10Z' curator: claude action: GROUND_CAUSAL_PREDICATES changes: Grounded 4 causal-edge predicate_id field(s) via mappings/predicate_grounding.tsv (METPO:2000202×1, RO:0002326×1, RO:0002212×1, RO:0002211×1). llm_assisted: true - timestamp: '2026-06-24T17:23:31Z' curator: claude action: GROUND_CAUSAL_NODES changes: Grounded 3 causal-node grounding field(s) via mappings/node_grounding.tsv (GO:1990573×1, CHEBI:27592×1, CHEBI:71578×1). llm_assisted: true