圆红冬孢酵母高产红酵母红素的机制解析及途径强化

红酵母红素是一种优质高效的天然抗氧化剂，其生物合成途径的高产调控机制尚不清晰。本项目拟以前期获得的高产红酵母红素Rhodosporidium toruloides突变株A1-15-BRQ为研究对象，首先，采用染色体步移及全基因组重测序技术，挖掘与红酵母红素高产相关的突变位点；采用转录组学及蛋白质组学，挖掘响应内源突变和外源碳氮比变化的关键基因或调控位点。其次，通过基因敲除、基因回补，结合RT-PCR和产物分析对所挖掘位点进行甄别，阐明关键位点导致的红酵母红素高产机制。最后，采用多基因共表达/敲除以及启动子优化策略，强化红酵母红素代谢合成途径，提高红酵母红素生物合成效率。本研究将揭示红酵母红素选择性高产的分子机制，为科学设计和调控食品添加剂的生物合成奠定理论基础。项目成果将推动基于微生物细胞工厂的食品添加剂生产，为现代食品工业注入新活力。

Torularhodin is an excellent natural antioxidant, however, the regulation mechanism of the biosynthetic pathway for its high productivity is still unknown. In this project, the study was carried out based on one Rhodosporidium toruloides mutant A1-15-BRQ, which was high in production of torularhodin. Firstly, genome walking and whole genome resequencing were used to identify mutation sites, and transcriptome and proteomics were further used to analyze the key genes or regulatory sites responding to endogenous mutations and exogenous changed C/N ratio. Secondly, molecular biology technologies such as gene knockout and gene overexpress, were used to identify the key genes, and combined with RT-PCR and product analysis, the regulation mechanism of high torularhodin production were elucidated. Finally, strategies, such as multi-gene co-expression, knockout and promoter optimization, were used to enhance the metabolic flux of torularhodin and to improve its efficiency. This study will reveal the molecular mechanism of torularhodin production, and help to lay a theoretical foundation for scientific design and regulation of biosynthesis of food additives. The results of the project will promote the production of food additives based on microbial cell factories and give prosperity to the modern food industry.