Enzyme-catalysed asymmetric reduction of ketones is an attractive tool for the production of chiral building blocks or precursors for the synthesis of bioactive compounds. Expression of robust ketoreductase (KRED) from Hansenula polymorpha was upscaled and applied for the asymmetric reduction of 31 prochiral carbonyl compounds (aliphatic and aromatic ketones, diketones and β-keto esters) to the corresponding optically pure hydroxy compounds. Biotransformations were performed with the purified recombinant KRED together with NADP⁺ recycling glucose dehydrogenase (GDH, Bacillus megaterium), both overexpressed in Escherichia coli BL21(DE3). Maximum activity of KRED for biotransformation of ethyl-2-methylacetoacetate achieved by the high cell density cultivation was 2499.7 ± 234 U g^–1_DCW and 8.47 ± 0.40 U·mg^–1_E, respectively. The KRED from Hansenula polymorpha is a very versatile enzyme with broad substrate specificity and high activity towards carbonyl substrates with various structural features. Among the 36 carbonyl substrates screened in this study, the KRED showed activity with 31, with high enantioselectivity in most cases. With several ketones, the Hansenula polymorpha KRED catalysed preferentially the formation of the (R)-secondary alcohols, which is highly valued.

酶催化的酮的不对称还原是生产手性构件或合成生物活性化合物的前体的有吸引力的工具。扩大了多形汉逊酵母中健壮的酮还原酶（KRED）的表达，并将其用于将31种手性羰基化合物（脂族和芳族酮，二酮和β-酮​​酯）不对称还原为相应的光学纯羟基化合物。用纯化的重组KRED和NADP ⁺循环葡萄糖脱氢酶（GDH，Bacillus megaterium）进行生物转化，二者均在大肠杆菌中过表达。BL21（DE3）。用于由高细胞密度培养实现乙基-2-甲基乙酰的生物转化KRED的最大活性为2499.7±234ü克^-1 _DCW和8.47±0.40 U·毫克^-1 _ê，分别。多形汉逊酵母的KRED是一种用途非常广泛的酶，具有广泛的底物特异性，并且对具有各种结构特征的羰基底物具有很高的活性。在这项研究中筛选的36种羰基底物中，KRED在31种情况下显示出活性，在大多数情况下具有高对映选择性。多态汉逊酵母KRED具有几种酮，优先催化（R）-仲醇的形成，这一价值很高。