A β‐ketoacyl‐ACP reductase (FabG) gene from Bacillus sp. ECU0013 was heterologously overexpressed in Escherichia coli and the encoded protein was purified to homogeneity. The recombinant reductase could reduce a broad spectrum of prochiral ketones including aromatic ketones and keto esters and showed the highest activity in the asymmetric reduction of ethyl 2‐oxo‐4‐phenylbutyrate (OPBE). Using E. coli cells coexpressing both FabG and glucose dehydrogenase (GDH) genes, as much as 620 g⋅L⁻¹ of OPBE was almost stoichiometrically converted to ethyl (S)‐2‐hydroxy‐4‐phenylbutyrate [(S)‐HPBE] with excellent (>99%) enantiomeric excess. More importantly, the process could be performed smoothly without external addition of an expensive cofactor as usually done and could be scaled up very easily. All these positive features demonstrate the applicability of this reductase for the large‐scale production of optically active α‐hydroxy acids/esters.

中文翻译：

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具有宽底物谱的细菌还原酶可有效还原620 g·L-1的2-氧代-4-苯基丁酸乙酯

芽孢杆菌属的β-酮酰基-ACP还原酶（FabG）基因。ECU0013在大肠杆菌中异源过表达，并且将编码的蛋白质纯化至同质。重组还原酶可以还原广谱的手性酮，包括芳族酮和酮酯，并且在2-氧代-4-苯基丁酸乙酯（OPBE）的不对称还原中表现出最高的活性。使用共表达FabG和葡萄糖脱氢酶（GDH）基因的大肠杆菌细胞，几乎以化学计量将多达620 g·L ^-1的OPBE转化为（S）-2-羟基-4-苯基丁酸乙酯[（S）-HPBE]的对映体过量（> 99％）。更重要的是，该过程可以顺利进行，而无需像通常那样在外部添加昂贵的辅因子，并且可以很容易地扩大规模。所有这些积极的特征证明了该还原酶在光学活性α-羟酸/酯的大规模生产中的适用性。