identifier: traitmech:000148
label: beta-galactosidase activity
definition: A physiological enzyme-activity phenotype in which a cell produces active
  beta-galactosidase enzymes that hydrolyze lactose into glucose and galactose.
definition_source: DOI:10.3389/fmicb.2021.742300
trait_category: PHYSIOLOGY
term_kind: CLASS
mapping_status: PROPOSED
parent_traits:
- METPO:1000059
evidence:
- reference: DOI:10.3389/fmicb.2021.742300
  snippet: β-Galactosidase (EC 3.2.1.23), also referred to as lactase, is an important
    member of glycosyl hydrolase, which can hydrolyze O-glycosidic bonds of lactose
    by hydrolysis reaction, resulting in the production of glucose and galactose
  notes: Zhou et al. define beta-galactosidase as EC 3.2.1.23, a lactose-hydrolyzing
    glycosyl hydrolase that produces glucose and galactose, grounding the enzyme activity
    named by the organism-level phenotype.
- reference: DOI:10.1128/jcm.22.3.333-335.1985
  snippet: Selenomonas sputigena was positive for α-galactosidase, β-galactosidase,
    and α-glucosidase (API ZYM strip) and for α-glucosidase, β-glucosidase, and α-galactosidase
    (API An-Ident strip).
  notes: Tanner et al. detected beta-galactosidase in Selenomonas sputigena with the
    API ZYM enzyme activity panel.
canonical_examples:
- taxon_id: NCBITaxon:69823
  taxon_label: Selenomonas sputigena
  note: Tanner et al. reported Selenomonas sputigena as positive for beta-galactosidase
    in the API ZYM enzyme activity panel.
  reference: DOI:10.1128/jcm.22.3.333-335.1985
discussions:
- discussion_id: beta-galactosidase-activity-xref-gap
  prompt: Resolve an exact external ontology class for beta-galactosidase activity
    before adding a TraitRecord xref.
  kind: CURATION_TODO
  status: OPEN
  rationale: GO:0004565 carries the same beta-galactosidase activity label but denotes
    the enzyme molecular function rather than the organism-level beta-galactosidase
    production phenotype, so it is appropriate as a causal-node grounding rather than
    an equivalent TraitRecord xref.
  posed_by: codex
  posed_date: '2026-09-11'
curation_history:
- timestamp: '2026-09-11T19:47:00Z'
  curator: codex
  action: MINTED_TRAITMECH_ID
  changes: Minted beta-galactosidase activity as a DOI-backed TraitRecord after a
    repository-wide duplicate review covering ignored and hidden files; METPO has
    no exact beta-galactosidase activity class yet.
  llm_assisted: true