tert‐Butyl (3R,5S)‐6‐chloro‐3,5‐dihydroxyhexanoate ((3R,5S)‐CDHH) is an important chiral intermediate for the synthesis of rosuvastatin. The biotechnological production of (3R,5S)‐CDHH is catalyzed from tert‐butyl (S)‐6‐chloro‐5‐hydroxy‐3‐oxohexanoate ((S)‐CHOH) by a carbonyl reductase, and this synthetic pathway is becoming a primary route for (3R,5S)‐CDHH production due to its high enantioselectivity, mild reaction conditions, low cost, process safety, and environmental friendship. However, the requirement of the pyridine nucleotide cofactors, reduced nicotinamide adenine dinucleotide (NADH) or reduced nicotinamide adenine dinucleotide phosphate (NADPH) limits its economic flexibility. In the present study, a recombinant Escherichia coli strain harboring carbonyl reductase R9M and glucose dehydrogenase (GDH) was constructed with high carbonyl reduction activity and cofactor regeneration efficiency. The recombinant E. coli cells were applied for the efficient production of (3R,5S)‐CDHH with a substrate conversion of 98.8%, a yield of 95.6% and an enantiomeric excess (e.e.) of >99.0% under 350 g/L of (S)‐CHOH after 12 hr reaction. A substrate fed‐batch strategy was further employed to increase the substrate concentration to 400 g/L resulting in an enhanced product yield to 98.5% after 12 hr reaction in a 1 L bioreactor. Meanwhile, the space–time yield was 1,182.3 g L⁻¹ day⁻¹, which was the highest value ever reported by a coupled system of carbonyl reductase and glucose dehydrogenase.

中文翻译：

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使用羰基还原酶和葡萄糖脱氢酶的高时空收率生产（3R，5S）-6-氯-3,5-二羟基己酸叔丁酯。

叔丁基（3 R，5 S）-6-氯-3,5-二羟基己酸酯（（3 R，5 S）-CDHH）是合成瑞舒伐他汀的重要手性中间体。（3 R，5 S）-CDHH的生物技术生产是通过羰基还原酶从叔丁基（S）-6-氯-5-羟基-3-氧代己酸（（S）-CHOH）催化的，并且该合成途径正在成为（3 R，5 S）-CDHH的生产是由于其高对映选择性，温和的反应条件，低成本，工艺安全性和环境友好性。但是，对吡啶核苷酸辅因子，减少的烟酰胺腺嘌呤二核苷酸（NADH）或减少的烟酰胺腺嘌呤二核苷酸磷酸（NADPH）的需求限制了其经济灵活性。在本研究中，具有羰基还原活性和辅因子再生效率高的重组羰基还原酶R 9M和葡萄糖脱氢酶（GDH）的大肠杆菌菌株被构建。重组大肠杆菌细胞用于有效生产（3 R，5 S）-CDHH，在12小时反应后，在350 g / L（S）-CHOH下，底物转化率为98.8％，产率为95.6％，对映体过量（ee。）> 99.0％。在1 L生物反应器中反应12小时后，进一步采用底物补料分批策略将底物浓度提高至400 g / L，从而使产品收率提高至98.5％。同时，时空产率为1,182.3 g L ^-1天^-1，这是羰基还原酶和葡萄糖脱氢酶耦合系统报道的最高值。