Zhang Xue, Xin Jiagang, Liu Mengyu, Zhang Yue, Luan Haoni, Feng Wei, Wang Fei, Xu Wei, Song Peng
School of Pharmaceutical Sciences and Food Engineering, Liaocheng University, Liaocheng, China.
National Key Laboratory of Macromolecular Drug Development and Manufacturing, Liaocheng, China.
Front Microbiol. 2025 Jan 22;16:1538237. doi: 10.3389/fmicb.2025.1538237. eCollection 2025.
Ursodeoxycholic acid (UDCA) can be used as a drug to treat various liver and bile diseases. Currently, the biological synthesis of UDCA is predominantly conducted via a two-step enzymatic process in which synthesis is catalyzed by 7α-hydroxysteroid dehydrogenase (7α-HSDH) and 7β-hydroxysteroid dehydrogenase (7β-HSDH) in succession, utilizing chenodeoxycholic acid (CDCA) as the substrate. In this study, an engineered () strain, designated UCA23, was constructed. This strain coexpressed four enzymes under the control of three independent T7 promoters: lactate dehydrogenase (LDH) derived from , glucose dehydrogenase (GDH) derived from , 7α-HSDH derived from , and 7β-HSDH derived from , enabling the whole-cell catalytic synthesis of UDCA from CDCA. This study systematically optimized the reaction parameters, including temperature, pH, and the addition of organic solvents and surfactants, for the whole-cell catalytic synthesis of UDCA by UCA23, and at the 2 L level, a UDCA conversion rate of 99% was achieved with 100 mM CDCA in 2 h, which is the highest level of conversion of a high-concentration CDCA substrate reported to date.
熊去氧胆酸（UDCA）可作为一种药物用于治疗各种肝脏和胆汁疾病。目前，UDCA的生物合成主要通过两步酶促过程进行，其中以鹅去氧胆酸（CDCA）为底物，依次由7α-羟基类固醇脱氢酶（7α-HSDH）和7β-羟基类固醇脱氢酶（7β-HSDH）催化合成。在本研究中，构建了一种工程化（）菌株，命名为UCA23。该菌株在三个独立的T7启动子控制下共表达四种酶：来源于（此处原文缺失相关信息）的乳酸脱氢酶（LDH）、来源于（此处原文缺失相关信息）的葡萄糖脱氢酶（GDH）、来源于（此处原文缺失相关信息）的7α-HSDH和来源于（此处原文缺失相关信息）的7β-HSDH，能够实现从CDCA全细胞催化合成UDCA。本研究系统地优化了UCA23全细胞催化合成UDCA的反应参数，包括温度、pH值以及有机溶剂和表面活性剂的添加，在2 L规模下，2 h内100 mM CDCA的UDCA转化率达到99%，这是迄今为止报道的高浓度CDCA底物转化率的最高水平。
