Alcaligenes faecalis CGMCC 1.2006整细胞催化邻氯扁桃腈动态动力学拆分制备（R）-邻氯扁桃酸

从6株粪产碱杆菌中筛选出对邻氯扁桃腈具有较高芳基乙腈水解酶活性和中等对映选择性的Alcaligenes faecalis CGMCC 1.2006.研究了反应介质对Alcaligenes faecalis CGMCC 1.2006芳基乙腈水解酶活性和对映选择性的调控作用.反应介质中水溶性辅溶剂如甲醇的加入降低芳基乙腈水解酶活性,但显著提高对映选择性.而非离子表面活性剂的加入具有相反的作用.系统优化了底物浓度、细胞浓度、pH、温度和反应时间等反应条件对芳基乙腈水解酶活性和对映选择性的影响.在最优反应条件下,采用分批补料策略,(R)-邻氯扁桃酸的产量在22 h内达到32.2 g/L,产率82.4%,ee 93.1%.以邻氯苯甲醛和氰化钾为底物合成(R)-邻氯扁桃酸,收率89.5%,ee98.6%.

Preparation of (R)-o-Chloromandelic Acid via Dynamic Kinetic Resolution of o-Chloromandelonitrile by Whole Cells of Alcaligenes faecalis CGMCC 1.2006

Alcaligenes faecalis CGMCC 1.2006 with higher arylacetonitrilase activity and moderate enantioselectivity towards o-chloromandelonitrile was screened from six microbial strains belonging to Alcaligenes faecalis. The regulating effects of reaction medium on both activity and enantioselectivity of arylacetonitrilase were studied. The addition of water-soluble co-solvents such as methanol into the reaction medium decreased the activity of arylacetonitrilase, but enhanced the enantioselectivity significantly. Addition of non-ionic surfactants possessed the reverse effects. The effects of reaction conditions such as substrate concentration, cell concentration, pH, temperature and reaction time on the activity and enantioselectivity of arylacetonitrilase were also optimized systematically. Under the optimal reaction conditions, the fed-batch production of (R)-o-chloromandelic acid was attained with 32.2g/L productivity within 22h, in 82.4% yield and 93.1% ee. With o-chlorobenzaldehyde and potassium cyanide as the substrates, (R)-o-chloromandelic acid was also produced in 89.5% yield and 98.6%ee.