Preparation of (R)-(?-mandelic acid and its derivatives from racemates by enantioselective degradation with a newly isolated bacterial strain Alcaligenes sp. ECU0401

详细信息    查看全文

• 作者：Yu-Cai He ; Jian-He Xu ; Jiang Pan ; Li-Ming Ouyang and Yi Xu
• 关键词：(R) ; (− ; ) ; Mandelic acid ; Alcaligenes sp. ECU0401 ; (S) ; (+) ; Mandelic acid dehydrogenase ; Enantioselective degradation ; Optical resolution
• 刊名：Bioprocess and Biosystems Engineering
• 出版年：2008
• 出版时间：August, 2008
• 年：2008
• 卷：31
• 期：5
• 页码：445-451
• 全文大小：377.5 KB

文摘

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 ¡ãC, 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.