耐超高渗工业酵母的CgHOG途径及其抗逆性应答转录调节研究

The low tolerances to substrate and fermentation products (stress resistance) of the industrial strains are a common problem which has a seriously impact to fermentation industry. In this project, we focus on the high osmolarity glycerol mitogen-activated protein kinase pathway of an independent-property-right hyperosmotic-tolerant industrial yeast. On the basis of whole-genome sequencing, we confirm the genes involved in CgHOG by bioinformatics, and molecular biology methods. Upon stress, the transcription, express or phosphorylation of key genes will be studied by transcriptomics, RT-PCR and bloting technology. A novel stress-resistance response CgHOG pathway and the response regulation mechanism will be performed. In summary, this study provides a series of novel genes, material, technique and pathway in the breeding of industrial strains, green fermentation technology and the crop improvement on salt or drought tolerance.

发酵工业菌株对底物产物耐受（抗逆）性差是共性问题，是急需解决的严重影响发酵工业发展的“瓶颈”之一，项目以自主产权耐高渗工业酵母的抗逆CgHOG应答调控途径为研究对象，在本团队四十五年对该酵母的研究和已完成的全基因组测序基础上，利用生物信息学、分子生物学等手段进一步确认CgHOG应答关键基因及转录因子；通过转录组、ChIP-PCR、mRNA定量和Bloting等技术研究对逆境的应答、转录表达和磷酸化水平；勾画出新的抗逆CgHOG途径模式并揭示其高抗逆的应答调控机理。研究结果将为解决工业菌株选育、绿色发酵技术和耐盐耐旱作物改良中的难题提供新的基因、材料、技术和途径。

项目以自主产权具有超高渗透压耐受性的工业菌株产甘油假丝酵母C. glycerinogenes为对象，围绕原申报研究核心，利用全基因组测序、转录组学、染色质免疫沉淀-PCR等手段对其CgHOG途径的组成和参与高抗逆应答调节等展开研究。在完善其分子遗传操作平台的基础上，构建了大量试验用突变株，确认了CgHOG途径核心分子CgHog1及调控的相关基因（CgSTE11、CgSTL2等）的功能，发现CgHOG途径与S. cerevisiae HOG调控模式差异主要通过Sln1分支响应多种压力，特别是高渗透压胁迫；获得了CgHOG途径参与调控极端压力下菌丝的形态应答、甘油的高效摄取和快速合成、糖的高效转运、糠醛和乙酸抗逆、氨基酸特别是精氨酸和γ-氨基丁酸的转运及在胞内积累等抗逆应答方式；将有关抗逆研究运用在C. glycerinogenes生物转化未脱毒纤维素水解液生产乙醇的工业应用探索上，并获得较好的结果。累计发表SCI论文13篇，CSCD论文6篇，申请专利6项。培养2名博士研究生和5名硕士生。