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, comparable to the oxidation of ethanol. The organism has a preference for the S-enantiomer, and the kinetic resolution process obeys a simple relationship, indicating an enantiomeric ratio (E) of 19. The compound is converted into glycidic acid, although a transient accumulation of glycidaldehyde occurs initially. Determination of other parameters revealed a temperature optimum of 50 degrees C, long-term stability (cells in the resting state), and a pH optimum compatible with the chemical stability 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 quinohemoprotein ethanol dehydrogenase. Comparison with existing methods for enantiomerically pure glycidol production indicated a number of attractive points for the method described here, although definitive evaluation must await further studies on the long-term stability under process conditions, reusability of the cells, and the mechanism of glycidol inhibition.
Geerlof
A
A
Department of Microbiology and Enzymology, Delft University of Technology, The Netherlands.
Jongejan
J A
JA
van Dooren
T J
TJ
Racemakers-Franken
P C
PC
van den Tweel
W J
WJ
Duine
J A
JA
D000433:1-Propanol / Q000737:chemistry / Q000378:metabolism; D000091:Acetobacter / Q000378:metabolism*; D000429:Alcohol Oxidoreductases / Q000378:metabolism; D001709:Biotechnology; D004355:Drug Stability; D004852:Epoxy Compounds / Q000737:chemistry* / Q000378:metabolism*; D006863:Hydrogen-Ion Concentration; D007700:Kinetics; D010084:Oxidation-Reduction; D020005:Propanols; D013237:Stereoisomerism; D013696:Temperature
D004852:Epoxy Compounds; D020005:Propanols; D000433:1-Propanol; D000429:Alcohol Oxidoreductases; C019641:alcohol dehydrogenase (acceptor); C004312:glycidol