虾青素是一种酮类胡萝卜素，具有多种增进人类健康的生物学功能。法夫酵母是发酵生产天然虾青素的重要备选菌种。法夫酵母合成类胡萝卜素有“双环和单环”两种途径，它们是虾青素合成调控的重要节点，但“双环和单环”途径的调控规律仍不清晰，是制约法夫酵母虾青素发酵产量的关键因素之一。本项目拟对高产和低产法夫酵母进行代谢组分析，解析“双环和单环”途径中差异代谢物与相关基因的关系，采用CRISPR Cas9基因编辑技术对关键基因进行编辑，分析关键基因的功能及对“双环和单环”途径中代谢通量的调控。通过本研究，预期将解析法夫酵母虾青素“双环和单环”途径中crtYB、asy和crtI等关键基因的双功能酶的不同功能之间转变和协调机理以及表达不同剪辑产物的功能，阐明关键基因对虾青素合成代谢通量的调控规律，将有助于全面和准确的理解法夫酵母虾青素合成机制，为虾青素的发酵生产调控提供理论基础。

Astaxanthin, a ketocarotene, have variety of biological functions for improving human health. Phaffia rhodozyma is an important alternative strain for fermentation of natural astaxanthin. The pathway of the carotenoid synthesis in P. rhodozyma mainly includes “dicyclic and monocyclic” pathways, which are important nodes of astaxanthin synthesis regulation. However, the regulatory characteristics of the two pathways are still unclear, which is one of the key factors that restrict the astaxanthin fermentation yield by P. rhodozyma und metabolomics of high-yield and low-yield in P. rhodozyma was analyzed for expounding the relationship between differential metabolites and genes of the two pathways. Furthermore, CRISPR Cas9 gene editing technology would be used to precisely modify key genes for analyzing the functional mechanism of key genes/enzymes and the regulation of key genes on metabolic flux in “dicyclic and monocyclic” pathway. Through this project, it is expected to analyze the mechanism of transformation and coordination between the different functions of bifunctional enzymes such as crtYB, asy and crtI, and the function of different splicing of transcripts. Finally, we clarify the regulatory characteristics of the metabolic flux in astaxanthin synthesis. The project will help to comprehensively and accurately understand the astaxanthin synthesis mechanism in P. rhodozyma and provide a theoretical basis for regulating astaxanthin production.