Acetoin metabolism: stereochemistry of the acetoin produced by the pyruvate decarboxylase of wheat germ and by the α-acetolactate decarboxylase of Klebsiella aerogenes

Abstract

Acetoin (3-hydroxybutan-2-one)(1) produced from pyruvate and acetaldehyde by the pyruvate decarboxylase of wheat germ consists of a mixture of enantiomers with the (S)-(+)-isomer preponderating. With pyruvate alone as substrate, racemic acetoin is produced. Acetoin produced from pyruvate by the sequential action of the acetohydroxy acid synthetase and α-acetolactate decarboxylase of Klebsiella aerogenes consists solely of the (R)-(–)-isomer.