两相体系中固定化黏红酵母CCZU-G5催化合成(R)-2-羟基-4-苯基丁酸乙酯

Biosynthesis of ethyl(R)-2-hydroxy-4-phenylbutyrate catalyzed by immobilized Rhodotorula mucilaginosa CCZU-G5 in biphasic system

通过筛选得到一株高立体选择性还原2-氧代-4-苯基丁酸乙酯(OPBE)合成(R)-2-羟基-4-苯基丁酸乙酯[(R)-HPBE]的菌株并鉴定为黏红酵母。研究了在异辛烷/水两相体系中固定化黏红酵母CCZU-G5不对称还原OPBE合成(R)-HPBE的反应条件。结果表明最适的反应条件为:在异辛烷比例为10%条件下,底物浓度为100mmol/L,催化剂用量为0.45 g/mL,辅底物为40 g/L的葡萄糖。在建立的反应体系中反应16 h,(R)-HPBE产率最高,达83.5%,e.e.值99%以上。固定化酵母经7次重复使用后,产率和e.e.值分别维持在70%和99%以上。

A strain capable of reducing ethyl-2-oxo-4-phenylbutanoate （OPBE） into ethyl （R）-2- hydroxy-4-phenylbutyrate [（R）-HPBE] was screened and identified as Rhodotorula mucilaginosa. In an isooctane/organic solvent biphasic system, reaction conditions of the asymmetric reduction of OPBE for synthesizing optically active （R）-HPBE with immobilized Rhodotorula mucilaginosa CCZU-G5 cell were investigated. The results showed that the optimum reaction conditions were： ratio of isooctane 10%, concentration of OPBE 100 mmol/L, catalyst dosage 0.45 g/mL and 40 g/L glucose as co-substrate After 16 h of biotransforrnation under the optimum conditions, the yield of （R）-HPBE was as high as 83.5% and enantiomeric excess （e.e.）. value was more than 99%. These immobilized catalysts could be repeatedly used for seven times, and the yield and e.e. value were all over 70% and 99%, respectively.