Bioreduction Phenylketonuria Preparation Of Single Enantiomers Of 3 - Phenyl Lactic Acid

3-phenyllactic acid is very useful for synthesis of many important bioactive compounds. However the two enantiomers of 3-phenyllactic acid show different biological activity and different applications in pharmaceutical and chemical industry. As a consequence, synthesis of chiral 3-phenyllactic acid is very important.Chiral 3-phenyllactic acids were first resolved by capillary electrophoresis in this paper. Using 30 mmoI/L hydroxypropyl-#- cyclodextrin as chiral selector, and 100 mmol/L phosphate solution (pH 5.5) as running buffer, the baseline seperation of 3-phenyllactic acid enantiomers was achieved with resolution of 1.51 by capillary zone electrophoresis under seperation voltage 26kV at 25 *. Based on this result, a method for qualitative and quantitative determination of D-3-phenyllactic acid and phenylpyruvic acid was established.With phenylpyruvic acid as the sole carbon source, a bacterial strain T01 was isolated from 176 samples. The strain could reduce asymmetrically phenylpyruvic acid to D-3- phenyllactic acid of 100% ee. The strain was identified as Staphylococcus haemolyticus by Biolog system.The fermentation conditions of S. haemolyticus T01 were optimized. With 1.5% D-fructose as carbon source, 0.5% peptone and 0.1% yeast extract as mixed nitrogen sources, 0.5% NaCl added, and pH adjusted to 7.0, the strain showed highest activity after incubation at 28 *, 180 r/min for 30 h. The specific activity of the enzyme was 0.581 mU/g.The optimal condition for asymmetric reduction of phenylpyruvic acid was also investigated. The cells suspended in 50 mmol/L Tris-HCl buffer (pH 9.0)containing 0.05g/L cetyl pyridinium bromide could produce D-3-phenyIlactic acid of 100% ee with conversion rate of 39.6% in 21 h from 4g/L phenylpyruvic acid.The pathogenicity and its management of S.haemolyticus had been dicussed in this paper.