Genetically engineered Saccharomyces cerevisiae for kinetic resolution of racemic bicyclo[3.3.1]nonane-2,6-dione

Whole cells of the genetically engineered Saccharomyces cerevisiae strain TMB4100 (1% PGI, YMR226c) were Used as the biocatalyst for the kinetic resolution of racemic bicyclo[3.3.1]nonane-2,6-dione rac-1. The yeast's phosphoglucose isomerase activity was decreased, and the short-chain dehydrogenase/reductase encoded by YMR226c was overexpressed. This reduced the demand for the glucose to regenerate NADPH, while at the same time the reaction rate and selectivity towards (-)-1 became higher. The demand for yeast biomass also decreased, facilitating down-stream processing, which is of considerable importance oil a large scale. With 15 g dry weight/L of the genetically engineered yeast TMB4100 (1% PGI, YMR226c), 40 g/L rac-1 was kinetically resolved within 24 h producing pure (+)-1 with all enantiomeric excess (ee) of 100% after 75% conversion. This corresponds to a biochemical selectivity constant of E = 10.3 +/- 2.2. Thus, compared with conventional methods which use commercial baker's yeast as a biocatalyst, the reaction system was significantly improved, and Would be superior in a large-scale process. (C) 2008 Elsevier Ltd. All rights reserved.