Abstract
The separation and purification of two kinds of acetylacetoin reductases (AACRs) from Bacillus cereus YUF-4 were examined. NADPH-linked AACR (AACR I) and NADH-linked AACR (AACR II) were separated from each other by ammonium sulfate fractionation, DEAE-cellulose chromatography, and hydroxyapatite chromatography. The former was purified 3.4-fold with a yield of 10.0%, and the latter was purified 29-fold with a yield of 15.6%. The two enzymes differ from each other in some enzymic properties such as substrate specificity.