Diacetyl reductase ((R)-acetoin forming) (, ''(R)-acetoin dehydrogenase'') is an

enzyme Enzymes () are proteins that act as biological catalysts by accelerating chemical reactions. The molecules upon which enzymes may act are called substrates, and the enzyme converts the substrates into different molecules known as products. A ...

with systematic name ''(R)-acetoin:NAD⁺ oxidoreductase''. This enzyme catalyses the following chemical reaction : (R)-acetoin + NAD⁺

\rightleftharpoons

diacetyl + NADH + H⁺ 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

yeast Yeasts are eukaryotic, single-celled microorganisms classified as members of the fungus kingdom. The first yeast originated hundreds of millions of years ago, and at least 1,500 species are currently recognized. They are estimated to constitut ...

Saccharomyces cerevisiae ''Saccharomyces cerevisiae'' () (brewer's yeast or baker's yeast) is a species of yeast (single-celled fungus microorganisms). The species has been instrumental in winemaking, baking, and brewing since ancient times. It is believed to have been o ...

. This enzyme is different from EC 1.1.1.304, diacetyl reductase ((S)-acetoin forming).

References

EC 1.1.1 {{Enzyme-stub