Laboratory of Biocatalysis and Synthetic Biotechnology, State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, Shanghai 200237, China.
Appl Microbiol Biotechnol. 2013 Jul;97(14):6293-300. doi: 10.1007/s00253-012-4435-z. Epub 2012 Nov 11.
A new strain, Enterobacter sp. ECU1107, was identified among over 200 soil isolates using a two-step screening strategy for the enantioselective synthesis of (2S,3R)-3-phenylglycidate methyl ester (PGM), a key intermediate for production of a potent anticancer drug Taxol®. An organic-aqueous biphasic system was employed to reduce spontaneous hydrolysis of the substrate PGM and isooctane was found to be the most suitable organic solvent. The temperature and pH optima of the whole cell-mediated bioreaction were 40 °C and 6.0, respectively. Under these reaction conditions, the enantiomeric excess (ee(s)) of (2S,3R)-PGM recovered was greater than 99 % at approximately 50 % conversion. The total substrate loading in batch reaction could reach 600 mM. By using whole cells of Enterobacter sp. ECU1107, (2S,3R)-PGM was successfully prepared in decagram scale in a 1.0-l mechanically stirred reactor, affording the chiral epoxy ester in >99 % ee s and 43.5 % molar yield based on the initial load of racemic substrate.
一株新的肠杆菌属（Enterobacter sp.）菌株 ECU1107 被鉴定为能够对（2S,3R）-3-苯基缩水甘油酸甲酯（PGM）进行对映选择性合成的 200 余个土壤分离物之一，（2S,3R）-3-苯基缩水甘油酸甲酯（PGM）是生产强效抗癌药物紫杉醇的关键中间体。采用两相有机-水体系来减少底物 PGM 的自发水解，发现异辛烷是最合适的有机溶剂。全细胞介导的生物转化的最适温度和 pH 分别为 40°C 和 6.0。在这些反应条件下，当转化率约为 50%时，回收的（2S,3R）-PGM 的对映体过量（ee(s)）大于 99%。分批反应中的总底物负荷可以达到 600mM。使用肠杆菌属（Enterobacter sp.）ECU1107 的全细胞，在 1.0 升机械搅拌反应器中成功地以克级规模制备了（2S,3R）-PGM，基于外消旋底物的初始负荷，手性环氧酯的对映体过量（ee(s)）大于 99%，摩尔收率为 43.5%。
