调控脂滴形成数量增强重组酿酒酵母β-胡萝卜素合成能力的分子机制

细胞存储空间有限是制约类胡萝卜素过量合成的瓶颈。因此，有效增加产物的存储空间是保证细胞高效合成类胡萝卜素的前提条件。研究发现，除细胞膜外，脂滴也是储存类胡萝卜素重要的细胞器，其数量随类胡萝卜素水平的变化而改变。本研究基于反向代谢工程的原理，以多株合成不同水平的β-胡萝卜素重组酿酒酵母菌为研究对象，利用启动子工程技术，对脂滴形成途径中相关酶的表达水平进行精确和协同调控，合理增加脂滴的数量，以扩大产物的存储空间，进一步增强细胞合成β-胡萝卜素的能力。本研究对于解决制约类胡萝卜素高效合成的瓶颈问题，阐明脂滴的形成机制将具有重要的学术意义和应用价值，同时，研究结果也可为其它类异戊二烯产物的研究提供有益的借鉴。

The limitation of storage space in cells is the bottleneck restricting the excessive accumulation of carotenoid products. Therefore, increasing the storage space is the prerequisite for efficient synthesis of carotenoid. Besides cell membrane, lipid droplet (LD) is the main organelle for storing carotenoid in microbial cells, and its mumber is changed with the variation of carotenoid levels. In this study, based on the principle of reverse metabolic engineering, the recombinant Saccharomyces cerevisiae strains producing different levels of β-carotene were used as research object, the key genes related to LD formation were precisely and synergistically regulated through promoter engineering to rationally increase the numbers of LD, to enhance β-carotene production. These results are expected to solve the bottleneck problem of restricting efficient biosynthesis of carotenoid and elucidate the mechanism of LD formation. This study can also provide some valuable references for research of other isoprenoids production by microorganism.