啤酒酵母抗老化因子的筛选及其对啤酒风味稳定性的影响机制研究

Flavor stability affects the quality and shelf life of beer, and staling, as one of the main factors that affect the beer flavor stability, has been the hot spot in brewing yeast breeding research for a long time. However, former researches were mostly focused on the regulation of known anti-staling compounds and genes which would finitely improve the anti-staling ability of brewing yeast, and there seems no effective way to highly efficiently assemble series of multivariate anti-staling elements against the complex responses of cell oxidative stress and interactions of functional genes. This research will be based on the beer brewing yeast strain with different anti-staling capability, and the high efficient anti-staling elements will be selected through genomic and proteomic analysis. Furthermore, the interaction and physiological regulation mechanism will be investigated, which will reveal the mechanisms of different anti-staling elements on beer flavor stability. These anti-staling elements will be assembled without influencing the main flavor of beer and further applied in other types of yeast strains, which will lay a foundation for the development of new universal anti-staling elements.

风味稳定性影响啤酒质量及货架期，老化作为影响啤酒风味稳定性的主要因素之一，是啤酒酵母选育研究的热点。以往的研究大多对已知抗老化物质及基因单一调控有限地提高酵母抗老化能力，无法针对细胞抗氧化应力胁迫的复杂响应机制及功能基因间的交互作用快速实现多元化抗老化因子的高效串联组装。本研究基于不同抗老化能力的啤酒酵母菌株，结合基因组学与蛋白组学方法筛选高效抗老化因子，深入探讨其互作关系与生理调控机制，揭示不同抗老化因子及其串联组合对啤酒风味稳定性的影响机制，在不影响啤酒风味的基础上优化酵母抗老化因子串联组合，并进一步在其它类型酵母中进行应用，为具有普适性的新型抗老化元件的发掘奠定坚实的理论基础。

风味稳定性影响啤酒质量及货架期，老化作为影响啤酒风味稳定性的主要因素之一，是啤酒酵母选育研究的热点。以往的研究大多对已知抗老化物质及基因单一调控有限地提高酵母抗老化能力，无法针对细胞抗氧化应力胁迫的复杂响应机制及功能基因间的交互作用快速实现多元化抗老化因子的高效串联组装。本研究基于不同抗老化能力的啤酒酵母菌株，结合多组学方法筛选有效地抗老化因子，发现己糖转运途径、果糖与甘露糖途径，调控其代谢改变细胞壁多糖组成增强了细胞壁对环境胁迫的抗性；而氧化磷酸化代谢途径的弱化减少了ROS的产生、调控TCA循环途径等影响酵母细胞的抗氧化应激反应。研究发现与线粒体相关基因AAC1、ACS1、ADY2、DNM1的过表达，显著影响了啤酒酵母的抗氧化能力；糖转运相关基因HXT3、HXT4、HXT7的过表达以不依赖于胞内ROS、内源性ATP的方式促进啤酒酵母抗氧化能力；氨基酸代谢及转运相关基因LYS20及AGP1的过表达提高了啤酒酵母的H2O2抗性，促进了胞内ROS稳态，但对胞内能量代谢影响较小。本研究为具有普适性的新型抗老化元件的发掘奠定坚实的理论基础。