Department of Biochemical Engineering, School of Chemical Engineering and Technology, Tianjin University, Tianjin, People's Republic of China.
Lett Appl Microbiol. 2022 Oct;75(4):824-830. doi: 10.1111/lam.13754. Epub 2022 Jun 14.
As an intermediate in drug synthesis, uridine has practical applications in the pharmaceutical field. Bacillus subtilis is used as a host to boost uridine yield by manipulating its uridine biosynthesis pathway. In this study, we engineered a high-uridine-producing strain of B. subtilis by modifying its metabolic pathways in vivo. Overexpression of the aspartate ammonia-lyase (ansB) gene increased the relative transcriptional level of ansB in B. subtilis TD320 by 13·18 times and improved uridine production to 15·13 g l after 72-h fermentation. Overexpression of the putative 6-phosphogluconolactonase (ykgB) gene increased uridine production by the derivative strain TD325 to 15·43 g l . Reducing the translation of the amido phosphoribosyl transferase (purF) gene and inducing expression of the subtilisin E (aprE) gene resulted in a 1·99-fold increase in uridine production after 24 h shaking. Finally, uridine production in the optimal strain B. subtilis TD335, which exhibited reduced urease expression, reached 17·9 g l with a yield of 314 mg of uridine g glucose. To our knowledge, this is the first study to obtain high-yield uridine-producing B. subtilis in a medium containing only three components (80 g l glucose, 20 g l yeast powder, and 20 g l urea).
作为药物合成的中间体，尿苷在制药领域具有实际应用。枯草芽孢杆菌被用作宿主，通过操纵其尿苷生物合成途径来提高尿苷产量。在这项研究中，我们通过在体内修饰其代谢途径，工程改造了一株高产尿苷的枯草芽孢杆菌。天冬氨酸氨甲酰基转移酶（ansB）基因的过表达使枯草芽孢杆菌 TD320 中 ansB 的相对转录水平提高了 13.18 倍，经过 72 小时发酵后尿苷产量提高到 15.13 g/L。推测的 6-磷酸葡萄糖酸内酯酶（ykgB）基因的过表达使衍生菌株 TD325 的尿苷产量提高到 15.43 g/L。降低酰胺磷酸核糖基转移酶（purF）基因的翻译并诱导表达枯草杆菌蛋白酶 E（aprE）基因，使 24 小时摇瓶培养后尿苷产量增加了 1.99 倍。最后，在表达降低的脲酶的最佳菌株枯草芽孢杆菌 TD335 中，在仅含有三种成分（80 g/L 葡萄糖、20 g/L 酵母粉和 20 g/L 尿素）的培养基中，尿苷产量达到 17.9 g/L，产率为 314 mg 尿苷 g 葡萄糖。据我们所知，这是首次在仅含有三种成分（80 g/L 葡萄糖、20 g/L 酵母粉和 20 g/L 尿素）的培养基中获得高产尿苷的枯草芽孢杆菌。
