胶红酵母催化苯乙酮的不对称还原及吸附树脂的促进作用

以苯乙酮为模式底物,利用筛选的胶红酵母(Rhodotorula mucilaginosa)YS6-2为手性催化剂,不对称还原合成具有光学活性的1-苯基乙醇.结果表明：反应的立体选择性极高,合成的产物以(S)-型为主,其对映体过量值达99.0 %. 在设立的水相系统中,酵母细胞在发酵培养36 h、转化反应36 h、pH 6.6、温度34 ℃、2 %葡萄糖作为辅助底物的优化条件下,0.12 g/mL菌体（湿重）催化还原70 mmol/L苯乙酮的转化率达49.1 %. 同时,向反应体系中添加1 g D-101吸附树脂,因其控制水相中与细胞接触的底物浓度并进行产物的原位吸附,底物的转化率提高到75.5 %.

Asymmetric reduction of acetophenone with Rhodotorula mucilaginosa and promotion effect of resin adsorption

A yeast strain, Rhodotorula mucilaginosa YS6-2, was utilized for the asymmetric reduction of acetophenone to (S)-aryl ethanol in aqueous phase with enantiomeric excess at 99.0%. The parameters influencing the bioreduction were optimized. The results showed that, at optimized condition of the initial cell concentration at 0.12 g/mL (wet weight) cultured for 36 h, acetophenone at 35 mmol/L, the initial reaction pH at 6.6, temperature 34 ℃ and reaction for 36 h, with addition of glucose at 20 g/L as co-substrate, the conversion rate could reach 49.1 %. Due to the cellular toxicity of high concentration of substrate added and product yielded, macroporous adsorption resins which can control the substrate concentration and adsorb the product were introduced into the reaction system to improve the conversion. The results showed that 1 g D-101 resin exhibited the highest promotion activity, with the conversion rate reaching 75.5 %.