Abstract
Epimerization of (-) -isodihydrocarvone (I) to (-) -dihydrocarvone (II) by Pseudomonas fragi IFO 3458 was studied. I was easily epimerized to II by the growing cells, the resting cells or the cell-free extracts.
An epimerase catalyzing the conversion of I to II was partially purified from the bacterial extracts about 56-fold with heat-treatment, ammonium sulfate precipitation and DEAE-Sephadex A-50 column chromatography. By the action of this epimerase, the ratio of I to II becomes about 25:75 (K_??_3). It appeared that the epimerase is very stable to heat; the activity of epimerization remains 66 and 36% after treatment at 97°C for 60 and 120min, respectively.
