β-Carotene is a kind of high-value tetraterpene compound, which shows various applications in medical, agricultural and industrial areas owing to its antioxidant, anti-tumor and anti-inflammatory activities. In this study, Yarrowia lipolytica was successfully metabolically modified through the construction and optimization of β-carotene biosynthetic pathway for β-carotene production. The β-carotene titer in the engineered strain Yli-C with the introduction of the carotenogenesis genes crtI crtE and crtYB can reach 34.5 mg/L. With the overexpression of key gene in MVA pathway and the enhanced expression of fatty acid synthesis pathway, the β-carotene titer of the engineered strain Yli-CAH reached 87 mg/L, which was 152% higher than that of the strain Yli-C. Through the further expression of the rate-limiting enzyme tHMGR and the copy number of β-carotene synthesis related genes, the β-carotene production of Yli-C2AH2 strain reached 117.5 mg/L. The final strain Yli-C2AH2 produced 2.7 g/L β-carotene titer by fed-batch fermentation in a 5.0 L fermenter. This research will greatly speed up the process of developing microbial cell factories for the commercial production of β-carotene.

中文翻译：

---

通过代谢和发酵工程提高解脂耶氏酵母中 β-胡萝卜素的产量

β-胡萝卜素是一种高价值的四萜化合物，由于其抗氧化、抗肿瘤和抗炎等活性，在医疗、农业和工业领域有着广泛的应用。在本研究中，通过构建和优化用于生产β-胡萝卜素的β-胡萝卜素生物合成途径，成功地对解脂耶氏酵母进行了代谢修饰。引入类胡萝卜素生成基因crtI crtE和crtYB的工程菌Yli-C的β-胡萝卜素效价可达34.5 mg/L。随着MVA途径关键基因的过表达和脂肪酸合成途径表达的增强，工程菌株Yli-CAH的β-胡萝卜素效价达到87 mg/L，比菌株Yli-C高152% . 通过进一步表达限速酶tHMGR和β-胡萝卜素合成相关基因的拷贝数，Yli-C2AH2菌株的β-胡萝卜素产量达到117.5 mg/L。最终菌株 Yli-C2AH2 在 5.0 L 发酵罐中通过补料分批发酵产生 2.7 g/L β-胡萝卜素效价。该研究将大大加快开发用于商业化生产β-胡萝卜素的微生物细胞工厂的进程。