四川晒醋固态发酵过程中理化因子与真菌群落结构的动态变化规律

为了探究四川晒醋发酵过程中真菌群落的演替及关键理化因子的变化规律，本文利用国标法和高通量测序技术对醋醅的理化指标和真菌群落进行了解析，同时结合真菌群落和理化因子进行冗余分析，找出影响真菌群落变化的关键理化因子。结果表明，随着发酵的进行，醋醅的pH降低，水分、温度基本保持稳定，总酸、氨态氮含量先持续增加后保持稳定，还原糖含量先增加后减少。通过高通量测序结果表明，四川晒醋固态发酵过程中共有9个门、299个属水平的真菌参与演替变化。毕赤酵母属（Pichia）和横梗霉属（Lichtheimia）为主要优势真菌。经过聚类分析，可将固态发酵过程分为3个阶段（第1发酵阶段，第1~8 d；第2发酵阶段，第9~12 d；第3发酵阶段，第14~16 d）。由冗余分析结果可知，氨态氮、总酸是影响真菌群落结构的主要因素，氨态氮、总酸与发酵第1~8 d的真菌群落呈负相关，与发酵第9~16 d的真菌群落呈正相关。该研究揭示了晒醋固态发酵过程中的真菌群落的多样性和演替规律及其影响因素，为掌握固态发酵过程中真菌的变化规律以及后续与风味物质的关联奠定基础。

Dynamic Changes of Physicochemical Properties and Fungal Community Structure during Solid-state Fermentation of Sichuan Sun Vinegar

In order to explore the succession of fungal community and key physicochemical properties in the fermentation process of Sichuan sun vinegar, the physicochemical properties and fungal communities of vinegar fermented grains were analyzed by national standard method and high-throughput sequencing technology. At the same time, the redundancy analysis was carried out combined with fungal community and physicochemical properties to find out the key physicochemical properties affecting the change of fungal community. The results showed that with the fermentation, the pH of vinegar fermented grains decreased, the moisture and temperature remained stable, the total acid and ammonia nitrogen content increased first and then remained stable, and the reducing sugar content increased first and then decreased. The results of high-throughput sequencing showed that there were 9 phyla and 299 genera involved in the succession of fungi during the solid-state fermentation of Sichuan sun vinegar. Pichia and Lichtheimia were the dominant fungi. Through cluster analysis, the solid-state fermentation process could be divided into three stages (the first fermentation stage, days 1~8, the second fermentation stage, days 9~12, the third fermentation stage, days 14~16). The results of redundancy analysis showed that ammonia nitrogen and total acid were the main factors affecting the fungal community. Ammonia nitrogen and total acid were negatively correlated with fermentation days 1~8, and positively correlated with the fungal community at days 9~16 of fermentation. This study revealed the diversity, succession and influencing factors of fungal communities in the solid-state fermentation process of sun vinegar, which laid the foundation for mastering the variation law of fungi in the solid-state fermentation process and the subsequent association with flavor substances.