EFFICIENT PRODUCTION OF OPTICALLY-ACTIVE STYRENE EPOXIDES IN 2-LIQUIDPHASE CULTURES

Escherichia coli recombinants expressing xylene oxygenase (XO) from th e TOL plasmid pWWO of Pseudomonas putida mt-2 were used in two-liquid phase fermentations with n-octane as a semi-inert second liquid phase, to produce epoxides derived from styrene. The toxicity of styrene in a two-phase system was significantly reduced as compared to single-pha se fermentations. Styrene, 3-chlorostyrene, and 4-chlorostyrene were e fficiently oxidized by the biocatalyst yielding optically active epoxi des with enantiomeric excesses of 92%, 96%, and 37% respectively 3-Met hylstyrene and 4-methylstyrene, however, were primarily oxidized at th e methyl moiety rather than the vinyl group, thus resulting in the for mation of 3-vinylbenzylalcohol and 4-vinylbenzylalcohol. Small amounts of 3-methyl-and 4-methylstyrene epoxide were formed here also. These products were produced at an estimated enantiomeric excess of over 95% .