Construction of engineering bacteria for conversion of acetophenone to (S)-α-phenylethanol

Abstract:

[Background] (S)-α-phenylethanol is a kind of important pharmaceutical intermediate. Conversion of acetophenone into (S)-α-phenylethanol by engineering bacteria has the advantages of strong stereoselectivity and mild transformation conditions. The study of this synthetic method is of great significance for the future green industrial production. [Objective] Construction of engineering bacteria capable of transforming acetophenone into (S)-α-phenylethanol, and the study on its transformation conditions. [Methods] ReADH gene encoding carbonyl reductase and FDH gene encoding formate dehydrogenase were cloned from Rhodococcus erythropolis and Candida boidinii, respectively. The constructed pRSFDuet-ReADH-FDH (R1F2) and pRSFDuet-FDH-ReADH (F1R2) were transformed into Escherichia coli, respectively. The enzymatic assay of ReADH and FDH were analyzed. The optimized transformation conditions to produce (S)-α-phenylethanol were tested. [Results] The enzyme activity of ReADH and FDH in R1F2 were 6.7 U/mL and 7.6 U/mL, respectively. R1F2 had higher catalytic activity than F1R2. The optimum pH of ReADH and FDH were 6.0 and 8.5, respectively. The optimum temperature of the ReADH and FDH were 40 °C and 35 °C, respectively. The optimum pH and temperature for the reaction of acetophenone catalyzed by R1F2 is 7.5 and 30 °C. R1F2 co-expression strain could catalyze the reduction of acetophenone with high substrate concentration, the conversion of 400 mmol/L acetophenone was over 98%, and the e.e. of (S)-α-phenylethanol value was over 99%. [Conclusion] Conversion of acetophenone into (S)-α-phenylethanol by engineered strain has a good prospect for industrial application.