identifier: traitmech:000181
label: 2,3-butanediol fermentation
definition: A fermentation in which microorganisms convert sugars to acetoin and 2,3-butanediol
  neutral end products through the butanediol pathway.
definition_source: DOI:10.1186/s12934-023-02163-6
trait_category: METABOLISM
term_kind: CLASS
mapping_status: PROPOSED
parent_traits:
- METPO:1002005
synonyms:
- synonym_text: butanediol fermentation
  synonym_type: RELATED_SYNONYM
  source: https://asm.org/getmedia/40946f85-9357-4563-aa8a-994427efa825/Methyl-Red-and-Voges-Proskauer-Test-Protocols.pdf
evidence:
- reference: DOI:10.1186/s12934-023-02163-6
  snippet: 3-Hydroxybutanone (Acetoin, AC) and 2,3-butanediol (BD) are two essential
    four-carbon platform compounds with numerous pharmaceutical and chemical synthesis
    applications. AC and BD have two and three stereoisomers, respectively, while
    the application of the single isomer product in chemical synthesis is superior.
    AC and BD are glucose overflow metabolites produced by biological fermentation
    from a variety of microorganisms.
  notes: Li et al. define acetoin and 2,3-butanediol as microbial glucose-overflow
    fermentation products and review the enzymology of their stereoisomer formation.
- reference: https://asm.org/getmedia/40946f85-9357-4563-aa8a-994427efa825/Methyl-Red-and-Voges-Proskauer-Test-Protocols.pdf
  snippet: Bacteria fermenting sugars via the butanediol pathway produce acetoin (i.e.,
    acetyl methyl carbinol or 3-hydroxybutanone) as an intermediate which can be further
    reduced to 2,3-butanediol.
  notes: The ASM methyl-red/Voges-Proskauer protocol distinguishes the butanediol
    fermentation pathway by acetoin formation with further reduction to 2,3-butanediol.
- reference: DOI:10.1007/s00253-014-5526-9
  snippet: Klebsiella pneumoniae is known to produce meso-2,3-butanediol and 2S,3S-butanediol,
    whereas 2R,3R-butanediol was detected in the culture broth of K. pneumoniae CGMCC
    1.6366.
  notes: Chen et al. directly studied 2,3-butanediol stereoisomer formation by K.
    pneumoniae, supporting this species as a canonical 2,3-butanediol fermenter.
canonical_examples:
- taxon_id: NCBITaxon:573
  taxon_label: Klebsiella pneumoniae
  note: K. pneumoniae CGMCC 1.6366 produced multiple 2,3-butanediol stereoisomers
    in culture.
  reference: DOI:10.1007/s00253-014-5526-9
discussions:
- discussion_id: butanediol-fermentation-xref-gap
  prompt: Resolve an exact external ontology class for 2,3-butanediol fermentation
    before adding a TraitRecord xref.
  kind: CURATION_TODO
  status: OPEN
  rationale: No exact GO or external metabolism class was resolved for the organism-level
    2,3-butanediol fermentation phenotype; Voges-Proskauer assay terms, acetoin or
    butanediol chemical production reactions, and individual dehydrogenase molecular
    functions are shifted relative to this product-specific fermentation class.
  posed_by: codex
  posed_date: '2026-09-14'
curation_history:
- timestamp: '2026-09-14T03:36:23Z'
  curator: codex
  action: MINTED_TRAITMECH_ID
  changes: Minted 2,3-butanediol fermentation as a DOI- and stable-URL-backed product-specific
    fermentation TraitRecord after a repository-wide duplicate review covering ignored
    and hidden files; METPO has no exact 2,3-butanediol fermentation class yet and
    the placeholder is reserved in proposals/metpo_traitmech_v58.
  llm_assisted: true