[Expression and functions of (S)-carbonyl reductase II in Saccharomyces cerevisiaes spores].

OBJECTIVE

To realize efficient biotransformation of (S)-1-phenyl-1,2-ethanediol by recombinant (S)-carbonyl reductase II, we expressed (S)- carbonyl reductase II from Candida parapsilosis CCTCC M203011 and embedded it in the spores of Saccharomyces cerevisiae AN120.

METHODS

(S)-carbonyl reductase II gene was cloned from C. parapsilosis genome and expressed in S. cerevisiae AN120 by PCR amplification. When cultured with potassium acetate as the sole carbon source, the yeast spores were produced, and embedded the recombinant (S)-carbonyl reductase II. Using 10% W/V spores as biocatalysts, 6 g/L 2-hydroxyacetophenone as substrate, the biotransformation was carried out and the optical purity and yield of products were analyzed by HPLC. During the biotransformation of 2-hydroxyacetophenone to (S)-1-phenyl-1,2-ethanediol, the optimal temperature and pH, stability and reusability of the recombinant spores were determined.

RESULTS

The recombinant yeast spores showed excellent performance to give (S)-1-phenyl-1,2- ethanediol with a high optical purity of 99.3% and a high yield of 99.0% at the optimal temperature (40 °C) and pH (6.0). Compared with the recombinant Escherichia coli, the spores improved the yield of (S)-1-phenyl-1,2-ethanediol from 89.7% to 99.0%, and shortened the biotransformation duration from 48 h to 4 h. After being reused for 10 times, the recombinant spores biotransformed (S)-1-phenyl-1,2-ethanediol with a stable optical purity of about 99% and a yield over 85%.

CONCLUSION

The heterologous expression of oxidoreductases was first realized in yeast spores, which laid a solid foundation for efficient preparation of chiral compounds.