基于adh基因多样性的传统清香型白酒发酵过程中高级醇合成机理解析

高级醇是传统发酵食品重要风味物质组成，研究其合成机理对提升产品品质和安全性意义重大。阐明高级醇合成规律和明确高级醇合成直接相关微生物是深入揭示传统发酵食品发酵过程中高级醇合成机理的关键。醇脱氢酶作为高级醇代谢途径中的关键酶，其编码基因（adh）可作为联系高级醇代谢功能与微生物间的标记基因，表征混合微生物发酵过程高级醇代谢功能和研究潜在高级醇生产者。本研究以传统清香型白酒为例，在了解发酵过程中高级醇与微生物之间关系的基础上，设计简并引物扩增adh基因片段，利用高通量测序技术考察发酵过程中adh基因多样性和群落结构。基于adh基因多样性及群落结构特征，结合adh基因与高级醇之间的相关性和adh基因物种注释信息，研究发酵过程中高级醇合成规律，明确高级醇合成直接相关微生物，解析影响高级醇合成直接相关微生物的因素。本项目不仅能为建立高级醇调控措施奠定理论基础，还能为研究其他风味物质合成机理提供参考。

Higher alcohols are important flavor components of traditional fermented food and it is critical to study the synthesis mechanism of higher alcohols for improving the quality and safety of the traditional fermented food. The key to reveal the synthesis mechanism of higher alcohols in the fermentation process of traditional fermented food is to clarify the synthesis regularity of higher alcohols and to identify the directly related microorganisms of higher alcohols. The gene (adh) of alcohol dehydrogenase, the key enzyme in metabolic pathway of higher alcohols, can be applied as Marker gene to link the metabolic function of higher alcohols and microorganisms and to characterize the metabolic function of higher alcohol and study the potential producer of higher alcohols in the mixed fermentation process. In this study, the traditional Fen-flavor Baijiu is used as the research object to study the synthesis mechanism of higher alcohols in the mixed fermentation process. Firstly, the degenerate primers of adh are designed based on the correlation between higher alcohols and microorganisms in the mixed fermentation process. The diversity and community structure of adh is investigated by combining of the degenerate primers and high-throughput sequencing technology. Secondly, the synthesis regularity of higher alcohols in mixed fermentation process is studied and the microorganisms directly related to the synthesis of higher alcohols are identified based on the diversity and community structure changes of adh, correlation between the diversity of adh and higher alcohols and the annotation of adh. Finally, the influence factors of the microorganisms directly related to the synthesis of higher alcohols are studied. The implementation of this study can not only lay the theoretical foundation for establishing control measure of synthesis higher alcohols, but also provide the reference for the study of the synthesis mechanism of other flavor substance in traditional fermented food.