Purification and some properties of lactate dehydrogenase from Bacillus subtilis BS12

Lactate dehydrogenase (LDH. EC1.1.1.27) from Bacilus subtilis BS12 was purified to electrophoretic homogeneity by ammonium sulfate fractionation, CM-cellulose, DEAE-cellulose ionexchange chromatography and Sephadex G200 column chromatography. The enzyme was purified 10.25 fols with 23.2% recovery of activity. The subunit molecular weight was estimated to be 28000 daltons by SDS-polyacrylamide gel electrophoresis. The optimum pH and temperature for enzyme catalysis were 7.0 and 35℃, respectively.