Yao Zhuoyue, Li Ran, Jiang Shuai, Wu Heyun, Ma Qian, Xie Xixian
School of Biological Engineering, Tianjin University of Science and Technology, Tianjin 300457, China.
Key Laboratory of Industrial Fermentation Microbiology, Ministry of Education, Tianjin University of Science and Technology, Tianjin 300457, China.
Sheng Wu Gong Cheng Xue Bao. 2024 Aug 25;40(8):2432-2443. doi: 10.13345/j.cjb.240023.
Thymidine, as a crucial precursor of anti-AIDS drugs (e.g., zidovudine and stavudine), has wide application potential in the pharmaceutical industry. In this study, we introduced the thymidine biosynthesis pathway into the wild-type MG1655 by systems metabolic engineering to improve the thymidine production in . . Firstly, , , , , , and were successively deleted to block the thymidine degradation pathway and salvage pathway in the wild-type . MG1655. Then, the pyrimidine nucleoside operons from F126 were introduced to enlarge the metabolic flux of the uridylic acid synthesis pathway. Finally, the expression of uridylate kinase, ribonucleoside diphosphate reductase, thymidine synthase, and 5'-nucleotidase in the thymidine biosynthesis pathway was optimized to enhance the metabolic flux from uridylic acid to thymidine. The engineered THY6-2 strain produced 11.10 g/L thymidine in a 5 L bioreactor with a yield of 0.04 g/g glucose and productivity of 0.23 g/(L·h). In this study, we constructed a strain that used glucose as the only carbon source for efficient production of thymidine and did not harbor plasmids, which provided a reference for the research on other pyrimidine nucleosides.
胸苷作为抗艾滋病药物（如齐多夫定和司他夫定）的关键前体，在制药行业具有广泛的应用潜力。在本研究中，我们通过系统代谢工程将胸苷生物合成途径引入野生型MG1655，以提高胸苷产量。首先，依次删除了……、……、……、……、……和……，以阻断野生型MG1655中的胸苷降解途径和补救途径。然后，引入来自F126的嘧啶核苷操纵子，以扩大尿苷酸合成途径的代谢通量。最后，优化胸苷生物合成途径中尿苷酸激酶、核糖核苷二磷酸还原酶、胸苷合成酶和5'-核苷酸酶的表达，以增强从尿苷酸到胸苷的代谢通量。工程化的THY6-2菌株在5 L生物反应器中产生了11.10 g/L胸苷，产率为0.04 g/g葡萄糖，生产力为0.23 g/(L·h)。在本研究中，我们构建了一种以葡萄糖为唯一碳源高效生产胸苷且不含质粒的菌株，为其他嘧啶核苷的研究提供了参考。
