Hiroyuki Muraki

Mechanism for the formation of 2,3-butanediol stereoisomers in Bacillus polymyxa

Abstract The mechanism of the formation of 2,3-butanediol isomers in Bacillus polymyxa was studied. We proposed a new model with NADPH-linked diacetyl reductase (S-acetoin forming) and R(−)-2,3-butanediol dehydrogenase. The two enzymes were separated by Blue Sepharose CL-6B and their stereospecificities were identified using all of the pure isomers of 2,3-butanediol (R(−), S(+)m, and meso), acetoin (R(−) and S(+)) and the separation and measurement of these isomers. The presence of acetoin or butanediol racemase was not confirmed in our experiments.