为从理论上解决国产葡萄酒风味同质化严重的产业问题，本项目研究外源氨基酸干预葡萄汁有孢汉逊酵母（H.uvarum）与酿酒酵母（S.cerevisiae）混菌发酵产乙酸高级醇酯的机制。首先，以酰基转移酶活性筛选若干株葡萄汁有孢汉逊酵母，与酿酒酵母混菌发酵，通过酯生成量与香气特征揭示乙酸高级醇酯生成的表观调控特性，并优选一株高产菌株；其次，采用双隔室装置进行优选菌株混菌发酵，碳同位素标记前体氨基酸，通过氨基酸代谢流量、代谢物组分、酵母生理特性解析两酵母氨基酸代谢的互作机理，明确乙酸高级醇酯生成的关键代谢物与控制点；最后，在关键控制点添加外源前体氨基酸，采用RNA-Seq测序技术从转录水平分析酵母基因表达量变化，并分析碳、氮代谢网络中关键代谢物节点的代谢通量，阐明外源氨基酸干预混菌发酵中酵母互作生成乙酸高级醇酯的机制。研究结果将推动混菌发酵工艺的技术革新，塑造国产葡萄酒的风味特色。

To solve the industry issue regarding flavor homogenization of domestic wine in theory, this project will investigate the intervention mechanism of higher alcohol acetates (HAA) in mixed H.uvarum/S.cerevisiae fermentation by exogenous amino acids. Firstly, several H.uvarum strains will be selected according to alcohol acetyltransferases activity, then matched with S. cerevisiae in mixed fermentation to reveal the modulation characteristics of HAA production and select one strain with highest ester productivity by evaluating ester production and aroma characteristics. Secondly, the selected H.uvarum will be used for mixed fermentation with isotopically C-labeled amino acids using a double-compartment fermentation system, to give insight into the amino acid interaction between two yeasts as well as acquire key metabolites and control time-points during HAA production by analyzing the amino acid flux, extracellular metabolites, and yeast physiological properties. Finally, exogenous amino acids will be added at key control time-point to illustrate intervention mechanism of yeast interaction responsible for HAA production in mixed fermentation via exogenous amino acids, by assaying yeast gene expression with RNA-Seq and metabolic flux of key metabolites in carbon-nitrogen metabolic networks. The results will facilitate the technical innovation of mixed fermentation, and shape the flavor characteristics of Chinese wine.