4-氯乙酰乙酸乙酯羰基还原酶产生菌的筛选及产酶条件研究

从实验室保藏的菌株中,筛选到一株立体选择性较高的产4-氯乙酰乙酸乙酯(COBE)羰基还原酶的菌株———出芽短梗霉(Aureobasidiumpullulans)SW0202,菌体产酶条件研究表明,最佳的发酵培养基配方为:麦芽糖30.0g/L,酵母膏20.0g/L,蛋白胨3.0g/L,(NH4)2SO45.0g/L,KH2PO42.0g/L,MgSO4.7H2O0.7g/L,最适发酵温度及初始pH分别为:28°C和pH6.0。该菌在此条件下发酵培养24h,产菌丝体生物量16.78g干菌体/L,COBE羰基还原酶酶活力达到1007U/L。在COBE的转化反应中,产物S-CHBE的浓度达到10.12g/L,光学纯度>97%e.e.。

Screening and production of carbonyl reductase by Aureobasidium pullulans SW0202

Aureobasidium pullulans SW0202 for producing carbonyl reductase with high enantioselectivity was isolated from the microorganisms preserved in our laboratory. The conditions for enzyme formation of the strain were studied, and the results showed that the suitable compounds of the medium were as follows: 30.0 g/L of maltose, 20.0 g/L of yeast extract, 3.0 g/L of peptone, 5.0 g/L of (NH_4)_2SO_4, 2.0 g/L of KH_2PO_4 and 0.7 g/L of MgSO_47H_2O. The optimum fermentation temperature and initial pH of for enzyme formation were 28C and pH6.0, respectively. Cultured under the optimum conditions for 24h, about 1 007U/L and 16.78 g dry cells/L were obtained. The concentration of S-CHBE reached 10.12 g/L and its optical purify was higher than 97%e.e..