FACTORS RELEVANT TO THE PRODUCTION OF (R)-(-GLYCIDOL (2,3-EPOXY-1-PROPANOL) FROM RACEMIC GLYCIDOL BY ENANTIOSELECTIVE OXIDATION WITH ACETOBACTER-PASTEURIANUS ATCC-12874())

Acetobacter pasteurianus oxidizes glycidol with high activity, compara ble to the oxidation of ethanol. The organism has a preference for the S-enantiomer, and the kinetic resolution process obeys a simple relat ionship, indicating an enantiomeric ratio (E) of 19. The compound is c onverted into glycidic acid, although a transient accumulation of glyc idaldehyde occurs initially. Determination of other parameters reveale d a temperature optimum of 50 degrees C, long-term stability (cells in the resting state), and a pH optimum compatible with the chemical sta bility of glycidol. However, it was also noted that respiration rates decrease at concentrations of glycidol above 1 M. This is most likely caused by substrate inhibition of the glycidol-oxidizing enzyme, the q uinohemoprotein ethanol dehydrogenase. Comparison with existing method s for enantiomerically pure glycidol production indicated a number of attractive points for the method described here, although definitive e valuation must await further studies on the long-term stability under process conditions, reusability of the cells, and the mechanism of gly cidol inhibition.