temperature range high

Deep research

Generated by just research-trait; source: research/traits/environment/temperature_range_high-deep-research-falcon.md

# Curation report: microbial **temperature range high**

## 1. Scope and interpretation

**Target trait:** **“temperature range high”**  
**Identifier:** **`METPO:1000454`**  
**Parent:** `METPO:1000306`  
**Category:** ENVIRONMENT; **term kind:** CLASS; **mapping:** REVIEWED.

The trait should denote a **growth-supporting temperature range whose upper portion extends above approximately 40 °C**, not merely survival after a heat pulse. A practical annotation should record the complete tested growth range, medium, pressure, pH, salinity, atmosphere, and growth criterion. Recent literature often defines a thermophile by an optimum growth temperature above 45 °C, extreme thermophiles above approximately 65–70 °C, and hyperthermophiles above 80 °C. These conventions are useful qualifiers but are not identical to the supplied METPO definition: an organism can have a range extending above 40 °C without having an optimum above 45 °C. For example, cultured *Thermoanaerobacter kivui* has an optimum of 66 °C; under the reported experimental conditions its lowest observed growth temperature was 39 °C. *Pyrococcus furiosus* has an optimum near 100 °C, maximum of about 103 °C, and minimum near 65 °C. (lehmann2023adaptivelaboratoryevolution pages 1-2)

### Boundaries

Do **not** treat the following as sufficient evidence for `METPO:1000454`:

* **Heat-shock survival or acquired thermotolerance:** viability after exposure does not establish sustained growth.
* **High-temperature optimum or maximum alone:** these are related quantitative phenotypes, but the target is a range class.
* **Protein/enzyme thermostability:** it is a candidate mechanism, not organismal growth evidence.
* **Transient heat-shock expression:** induction at a supraoptimal temperature may protect an already thermophilic organism but does not by itself establish its basal thermophilic range.
* **Environmental sequence detection:** DNA from a taxon in hot water can reflect immigration, dormant/dead cells, or taxonomic misassignment. In an 85 °C spring, only 15 of 66 consistently detected genera had cultured strains documented to grow above 45 °C. (mondal2024aquificaeovercomescompetition pages 1-2, mondal2024aquificaeovercomescompetition pages 23-24)
* **Thermotolerance engineered into a mesophile:** useful causal evidence for a mechanism, but it should be marked heterologous and assay-specific unless sustained growth across a range is measured.

The phenotype is best modeled as an emergent outcome of **proteostasis, RNA stability, genome maintenance, membrane homeostasis, compatible-solute chemistry, and temperature-compatible metabolism**, rather than a single universal pathway.

## 2. Candidate nodes

### Trait and environmental nodes

| Candidate node | Type | Suggested grounding | Curation comment |
|---|---|---|---|
| temperature range high | phenotype | `METPO:1000454` | Exact target node. |
| ambient high temperature | environmental factor | Label only unless the project has an approved ENVO/PATO temperature node | Store actual °C values and assay duration as evidence metadata. |
| sustained microbial growth | biological process/assay outcome | `GO:0016049` (cell growth), if consistent with project practice | Prefer growth rate, biomass increase, CFU increase, or serial propagation over survival. |
| heat shock | experimental factor/process | `GO:0009408` (response to heat) for the response, not the exposure itself | Nearby but distinct from the target trait. |
| volcanic hot spring / hydrothermal habitat | environment | ENVO term should be selected against the exact sampled habitat | Habitat association is contextual evidence, not direct trait proof. |

### Genes, proteins, and complexes

| Candidate node | Type | Suggested grounding | Evidence status |
|---|---|---|---|
| reverse gyrase (`rgy`; PF0495 in *P. furiosus*) | enzyme/topoisomerase | `GO:0003918` DNA topoisomerase type II activity is **not sufficiently specific**; retain gene/protein label or use verified UniProt per strain | Strong, direct, but most relevant above ~90 °C and taxon-specific. |
| CspL | RNA chaperone/cold-shock-domain protein | Use the verified *Bacillus coagulans* protein accession; otherwise label only | Strong heterologous intervention evidence. |
| HSP20/small heat-shock proteins | molecular chaperone family | `GO:0051082` unfolded protein binding may describe function; verify protein accessions individually | Direct effects differ greatly among family members. |
| CeHSP17 | small heat-shock protein | Species-specific accession recommended | Strong heterologous evidence, but derived from *C. elegans*, not a microbe. |
| GroEL–GroES | group I chaperonin complex | `GO:1990220` GroEL–GroES complex | Supportive intervention evidence; smaller shift than CeHSP17. |
| thermosome α/β subunits | archaeal group II chaperonin | `GO:0005832` chaperonin-containing T-complex may be considered only after checking ontology scope | Heat-induced in *Sulfolobus*; causal trait evidence remains incomplete. |
| Phr | archaeal heat-shock transcriptional regulator | Label or verified UniProt | Regulates heat-inducible genes in *P. furiosus*; taxon-specific. |
| IPCT/DIPPS | di-myo-inositol-phosphate biosynthetic enzyme | Label plus verified UniProt/EC after sequence-level confirmation | Deletion reveals compensatory solutes rather than an essential phenotype. |
| GDGT ring synthase GrsB | lipid-modifying enzyme | Verified UniProt only | Expression/composition evidence is mainly associative and stress-specific. |
| DNA-repair proteins | module | `GO:0006281` DNA repair | Biologically plausible module; individual causal genes need direct evidence. |
| methionine-sulfoxide reductases/ROS-defense enzymes | redox-repair module | Ground individual proteins/functions after verification | Hot-spring metagenomic enrichment is associative, not causal. |

### Chemicals and membrane structures

| Candidate node | Type | Suggested grounding | Comment |
|---|---|---|---|
| di-myo-inositol phosphate (DIP) | compatible solute | ChEBI identifier should be verified before YAML insertion; label-only is safer here | Heat-induced, but functionally replaceable by MG or aspartate. |
| mannosylglycerate (MG) | compatible solute | Verify exact stereochemical CHEBI record | Interchangeable with DIP in *P. furiosus*. |
| L-aspartate | compatible solute/metabolite | `CHEBI:29991` | Compensates for DIP loss in *T. kodakarensis*. |
| glycerol dialkyl glycerol tetraether (GDGT) | archaeal membrane lipid class | Use verified LIPID MAPS/ChEBI class identifier | Class composition and cyclization matter; do not treat all GDGTs as equivalent. |

Showing the first 60 of 250 lines of findings; the linked file also carries the run's front matter and the prompt it was given — read the full report.