Bacillus megaterium WZ009催化合成（R）-4-氯-3-羟基丁酸乙酯和（S）-3-羟-基-γ-丁内酯

摘要

以外消旋4氯3羟基丁酸乙酯为唯一C源的富集培养筛选得到一株菌株WZ009，经16S rDNA测序鉴定为巨大芽胞杆菌（ Bacillus megaterium）。 B�megaterium WZ009静息细胞可以立体选择性催化（ S）4氯3羟基丁酸乙酯水解和脱氯反应得到光学纯的（ R）4氯3羟基丁酸乙酯（ e�e�≥99％）和（ S）3羟基γ丁内酯（ e�e�≥95％）。笔者对B�megaterium WZ009不对称催化反应影响因素（温度、pH、中和剂、底物浓度、时间进程以及细胞重复利用）进行优化研究，确定了该反应体系最优条件：底物浓度200 mmol/L，中和剂氨水，pH 7�2，40℃反应12 h，转化率达到50�6％，底物对映体过量值为99�6％。该生物催化合成（ R）4氯3羟基丁酸乙酯和（ S）3羟基γ丁内酯过程具有良好的工业化应用前景。%A new strain WZ009 was isolated by enrichment culture with ethyl-4-chloro-3-hydroxybutyrate as the only source of carbon�Strain WZ009 was identified as Bacillus megaterium by 16S rDNA gene sequencing. The resting cell of B�megaterium WZ009 catalyzed stereoselective hydrolysis and dechlorination of ethyl-(S)-4-chloro-3-hydroxybutyrate,obtained high optical active ethyl-(R)-4-chloro-3-hydroxybutyrate ( e�e� ≥99%) and ( S )-3-hydroxy-γ-butyrolactone ( e�e� ≥95%) . The catalytic characteristics of B�megaterium WZ009 were studied. The optimal conditions were obtained as follows:substrate concentration 200 mmol/L,reaction temperature 40 ℃,pH 7�2, neutralizing agent NH3·H2 O and reaction time 12 h. Under the above-mentioned conditions, the conversion was 50�6% with e�e�99�6%. The biocatalysis synthesis of ethyl-( R )-4-chloro-3-hydroxybutyrate and ( S )-3-hydroxy-γ-butyrolactone has a bright industrialization future.