PhysicochemicalRoleEnum

Name
PhysicochemicalRoleEnum
Description
Chemical or physical function an ingredient performs in the medium, independent of what element it supplies. One of three orthogonal role facets (with NutritionalRoleEnum and CellularMetabolicRoleEnum).
From schema
https://w3id.org/mediaingredientmech
Permissible values
Buffer
Text
BUFFER
Description
Maintains stable pH via a conjugate acid–base system.
Meaning
CHEBI:35225
Solidifying agent
Text
SOLIDIFYING_AGENT
Description
Gelling agent for solid or semi-solid media (e.g., agar, gellan gum, silica gel).
Chelator
Text
CHELATOR
Description
Sequesters metal ions to control availability, toxicity, or precipitation (e.g., EDTA, NTA, citrate).
Meaning
CHEBI:38161
Surfactant
Text
SURFACTANT
Description
Reduces surface tension for emulsification, solubilization, or membrane permeabilization (e.g., Tween, Triton X-100).
Meaning
CHEBI:35195
Mappings
Reducing agent
Text
REDUCING_AGENT
Description
Lowers the redox potential of the medium (e.g., sodium sulfide, cysteine, thioglycolate, dithiothreitol).
Meaning
CHEBI:63247
Oxidizing agent
Text
OXIDIZING_AGENT
Description
Raises the redox potential of the medium.
Meaning
CHEBI:63248
Ph indicator
Text
PH_INDICATOR
Description
Colorimetric acid–base indicator dye (e.g., phenol red, bromothymol blue).
Meaning
CHEBI:50407
Redox indicator
Text
REDOX_INDICATOR
Description
Colorimetric indicator of redox potential (e.g., resazurin turns pink under mildly oxidizing conditions).
Mappings
Selective agent
Text
SELECTIVE_AGENT
Description
Antimicrobial or otherwise selective agent used to enrich for or against particular organisms (e.g., antibiotics, bile salts, high salt, azide).
Mappings
Antifoam
Text
ANTIFOAM
Description
Suppresses foaming in aerated or vigorously mixed cultures (e.g., silicone antifoam, polypropylene glycol).
Meaning
CHEBI:77973
Osmotic agent
Text
OSMOTIC_AGENT
Description
Contributes primarily to the osmotic strength of the medium (e.g., NaCl at high concentration, sucrose, glycerol as osmolyte). NOTE: shares `mappings: CHEBI:25728 (osmolyte)` with CellularMetabolicRoleEnum.OSMOPROTECTANT. Auto-classifiers driven by the SSSOM must NOT fan a single CHEBI:25728 annotation out to both facets — this is a medium-side role, whereas OSMOPROTECTANT is an intracellular, organism-conditional role. Assign OSMOPROTECTANT only when there is organism-context evidence.
Mappings
Precipitation inhibitor
Text
PRECIPITATION_INHIBITOR
Description
Prevents precipitation of otherwise poorly-soluble medium components (e.g., citrate keeping iron soluble at neutral pH).