In summary, the study has revealed that substituted phenylacetic
acids can in principal be produced from correspondingly
substituted styrenes by means of suitable styrene-degrading
bacterial isolates which harbor enzymes of the side-chain
oxygenation. 4-chlorostyrene turned out to be a well suited
co-metabolic substrate and in particular, it was most efficiently
converted by P. fluorescens ST. Considerable differences were also
observed in the enantioselective potential of the initial degradation
pathway relevant in the conversion of a-substituted styrene
analogs. Again, strain ST showed highest specificity and an
enantiomeric excess of 40% was determined for the (S)-4-
chloro-a-methylphenylacetic acid. The remarkable ability of a
Gordonia-isolate to convert 4-isobutyl-a-methylstyrene into
ibuprofen demonstrates a novel route towards this drug. However,
a biotechnological application of these strains requires further
optimization approaches to improve the product yields