Bacterial Butylene Glycol Dehydrogenase and Diacetyl Reductase* by Harold

The early literature indicates much confusion as to the origin of acetylmethylcarbinol and butylene glycol in microbiological fermentations. Happold and Spencer (1) have reviewed much of this early work and have studied in detail the conditions for the formation of acetylmethylcarbinol and butylene glycol from glucose and pyruvate by Aerobacter aerogenes. Juni (2) has demonstrated that acetoin arises from pyruvate via acetolactic acid as intermediate with A. aerogenes and other bacterial cells. Evidence that the butylene glycol-acetoin system is diphosphopyridine nucleotidelinked has been obtained by DeMoss et al. (3), who observed the reduction of DPN+’ by butylene glycol and the reoxidation of DPNH by acetoin in extracts of Leuconostoc mesenteroides. The work reported here deals with the isolation and partial purification of two enzyme systems from A. aerogenes and Staphylococcus aureus, one catalyzing the reversible oxidation by DPN+ of butylene glycol to acetoin and the other catalyzing an essentially irreversible reduction by DPNH of diacetyl to acetoin. These enzymes are referred to as butylene glycol dehydrogenase and diacetyl reductase respectively.