He Yu-Cai, Xu Jian-He, Pan Jiang, Ouyang Li-Ming, Xu Yi
Laboratory of Biocatalysis and Bioprocessing, State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, Shanghai, People's Republic of China.
Bioprocess Biosyst Eng. 2008 Aug;31(5):445-51. doi: 10.1007/s00449-007-0181-5. Epub 2007 Dec 12.
An enantioselective mandelate-degrading bacterium, Alcaligenes sp. ECU0401, was newly isolated from soil. By fed-batch culture, (R)-(-)-mandelic acid was successfully prepared in a 5-L fermenter with 32.8% isolated yield and >99.9% enantiomeric excesses (e.e.) from totally 3.04% (w/v) of racemic mandelic acid after 99 h of biotransformation. The optimal reaction pH and temperature were 6.5 and 30 degrees C, respectively. Using the resting cell as a biocatalyst for asymmetric degradation of racemic mandelic acid and chloro-substituted derivatives thereof, (R)-(-)-mandelic acid, (R)-(-)-o-chloromandelic acid, (S)-(+)-m-chloromandelic acid and (S)-(+)-p-chloromandelic acid were recovered with high analytic yields and excellent enantiomeric excesses (e.e. > 99.9%). (R)-(-)-Mandelic acid could also be obtained after 12 h of biotransformation with 41.5% isolated yield and >99.9% e.e.
从土壤中新分离出一株对映体选择性降解扁桃酸的细菌——产碱菌属ECU0401。通过分批补料培养，在5升发酵罐中，以3.04%（w/v）的外消旋扁桃酸为原料，经过99小时的生物转化，成功制备出（R）-（-）-扁桃酸，分离产率为32.8%，对映体过量值（e.e.）>99.9%。最佳反应pH值和温度分别为6.5和30℃。以静息细胞作为生物催化剂，用于外消旋扁桃酸及其氯代衍生物的不对称降解，可回收得到（R）-（-）-扁桃酸、（R）-（-）-邻氯扁桃酸、（S）-（+）-间氯扁桃酸和（S）-（+）-对氯扁桃酸，分析产率高，对映体过量值优异（e.e.>99.9%）。经过12小时的生物转化，也可获得（R）-（-）-扁桃酸，分离产率为41.5%，e.e.>99.9%。
