Enantioselective synthesis of enantiopure chiral alcohols using carbonyl reductases screened from Yarrowia lipolytica.

ABSTRACT

AIMS: We aimed to explore Yarrowia lipolytica carbonyl reductases as effective biocatalysts and to develop efficient asymmetric reduction systems for chiral alcohol synthesis. METHODS AND RESULTS: Yarrowia lipolytica carbonyl reductase genes were obtained via homologous sequence amplification strategy. Two carbonyl reductases, YaCRI and YaCRII, were identified and characterized, and used to catalyse the conversion of 2-hydroxyacetophenone (2-HAP) to optically pure (S)-1-phenyl-1,2-ethanediol. Enzymatic assays revealed that YaCRI and YaCRII exhibited specific activities of 6·96 U mg-1 (99·8% e.e.) and 7·85 U mg-1 (99·9% e.e.), respectively, and showed moderate heat resistance at 40-50°C and acid tolerance at pH 5·0-6·0. An efficient whole-cell two-phase system was established using reductase-expressing recombinant Escherichia coli. The conversion of 2-HAP (20·0 g l-1 ) conversion with the solvent of dibutyl phthalate was approximately 70-fold higher than in water. Furthermore, the two recombinant E. coli displayed biocatalyst activity and enantioselectivity towards several different carbonyl compounds, and E. coli BL21 (DE3)/pET-28a-yacrII showed a broad substrate spectrum. CONCLUSIONS: A new whole-cell recombinant E. coli-based bioreduction system for enantiopure alcohol synthesis with high enantioselectivity at high substrate concentrations was developed. SIGNIFICANCE AND IMPACT OF THE STUDY We proposed a promising approach for the efficient preparation of enantiopure chiral alcohols.