Cloning, expression and characterization of a novel (2R,3R) -2,3-butanediol dehydrogenase from Bacillus thuringiensis

Acetoin (3-hydroxy-2-butanone) is an important four-carbon compound widely used in the food industry and other industrial applications. This study aimed to identify a novel butanediol dehydrogenase that can efficiently catalyze the formation of acetoin. A novel butanediol dehydrogenase, BtBDH, was identified from Bacillus thuringiensis subsp. Kurstaki ACCC 10066, and its enzymatic properties were characterized. The optimum pH and temperature for the oxidation activity of BtBDH were 10.0 and 50 °C, respectively, and those for the reduction activities were 7.5 and 35 °C, respectively. In addition, it exhibits stability over a wide pH range (6–10) and temperatures up to 70 °C. BtBDH showed good stability after storage for 3 months at 4 °C. Moreover, ethylenediaminetetracetic acid (EDTA) inhibits the enzymatic activity of BtBDH, indicating that the enzyme is metal-dependent. This study characterized a novel (2R,3R) −2,3-butanediol dehydrogenase. Its excellent oxidation activity and stability ensure its great industrial application potential in the production of acetoin.