Han Yuchen, Gao Huayi, Wang Shuo, Ju Haiyan, Ge Ran, Xue Chaoyou, Liu Weidong, Jiang Xiaolong, Zhang Wuyuan
Key Laboratory of Engineering Biology for Low-carbon Manufacturing, Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin 300308, China.
University of Chinese Academy of Sciences, Beijing 100049, China.
ACS Synth Biol. 2025 Jul 18;14(7):2609-2618. doi: 10.1021/acssynbio.5c00032. Epub 2025 Jun 27.
7-Dehydrocholesterol (7-DHC) is a subcutaneous sterol and a precursor to various active vitamin D. Here, a strain equipped with the biosynthetic pathway for 7-DHC was constructed. 109.0 mg L of 7-DHC was achieved initially by introducing heterologous 24-dehydrocholesterol reductase () and overexpressing vital enzymes. Following these modifications, the dynamic regulation of the ergosterol pathway and multicopy expression of resulted in an 86.3% increase in the 7-DHC titer. Subsequently, the effects of several organic solvents and surfactants on 7-DHC production were also explored. The addition of ε-polylysine increased the titer of 7-DHC by 99.1%. Finally, by assembling the pathway in peroxisomes and rebalancing the redox levels, the 7-DHC titer reached 517.4 mg L in shake flasks. Scale-up fermentation with a 5 L bioreactor demonstrated that 3.26 g L of 7-DHC was produced. The pathway refactoring strategy provides efficient production of 7-DHC in a sustainable manner.
7-脱氢胆固醇（7-DHC）是一种皮下甾醇，也是多种活性维生素D的前体。在此，构建了一种具备7-DHC生物合成途径的菌株。最初，通过引入异源24-脱氢胆固醇还原酶并过表达关键酶，实现了109.0 mg/L的7-DHC产量。经过这些改造后，麦角固醇途径的动态调控和[具体基因]的多拷贝表达使7-DHC产量提高了86.3%。随后，还探究了几种有机溶剂和表面活性剂对7-DHC生产的影响。添加ε-聚赖氨酸使7-DHC产量提高了99.1%。最后，通过将该途径组装到过氧化物酶体中并重新平衡氧化还原水平，摇瓶中7-DHC产量达到了517.4 mg/L。使用5 L生物反应器进行放大发酵表明，可生产3.26 g/L的7-DHC。该途径重构策略以可持续的方式实现了7-DHC的高效生产。
