The reaction is catalysed in the reverse direction. This activity is usually associated with butanediol dehydrogenase activity (EC 1.1.1.4 or EC 1.1.1.76). While the butanediol dehydrogenase activity is reversible, diacetyl reductase activity is irreversible. This enzyme has been reported in the yeastSaccharomyces cerevisiae. This enzyme is different from EC 1.1.1.304, diacetyl reductase ((S)-acetoin forming).
References
^Heidlas J, Tressl R (1990). "Purification and characterization of a (R)-2,3-butanediol dehydrogenase from Saccharomyces cerevisiae". Archives of Microbiology. 154 (3): 267–73. doi:10.1007/bf00248966. PMID2222122. S2CID21979677.