Highly enantioselective hydrolysis of phenyl-1,2-ethanediol cyclic carbonates by newly isolated Bacillus sp. ECU0015

A bacterial strain (No. ECU0015), which catalyzes the hydrolysis of phenyl-1,2-ethanediol cyclic carbonates (4-phenyl-1,3-dioxolan-2-one, 1) to (S)-1-phenyl-1,2-ethanediol (2) with high enantioselectivity, was newly isolated from soil samples utilizing the cyclic carbonate as sole carbon and energy source. The bacterium was later identified as Bacillus species by its 16S rDNA sequence and phylogenetic analysis. The optimal reaction temperature and pH for the asymmetric hydrolysis of 1 using whole cells were 35 °C and pH 7.3, respectively. Partial bio-oxidation of the produced (R)-diol was observed, resulting in an increase in the eep (enantiomeric excess of product) of the main product (S)-diol. Under the improved reaction condition, the target product (S)-diol was prepared in gram scale, affording an excellent eep (>99%) with a moderate yield (27.8%) as compared to the maximum theoretical yield of 50% for kinetic resolution. This strain of Bacillus sp. also displayed fairly good activity and enantioselectivity towards some other compounds tested, such as 2-acetoxy-2-phenylacetic acid (3) and its derivatives.