赤水晒醋醋酸发酵过程原核微生物群落及理化因子相关性分析

Correlation analysis of prokaryotic microbial community and physicochemical factors during the acetic acid fermentation of Chishui sun-dried vinegar

为了研究赤水晒醋醋酸发酵过程原核微生物群落结构的变化情况,采用高通量测序技术分析了醋醅中原核微生物群落的组成,检测了醋酸发酵过程基础理化指标(总酸、乙醇、还原糖和乳酸)的变化,并分析了理化因子与原核微生物属之间的相关性。结果表明,赤水晒醋醋酸发酵过程中醋酸乳杆菌属(Acetilactobacillus)和葡糖醋杆菌属(Gluconacetobacter)的相对丰度随着醋酸发酵的进行由0.11%和低于0.01%上升至36.779%和4.760%,乳杆菌属(Lactobacillus)和醋杆菌属(Acetobacter)的相对丰度随着醋酸发酵的进行先上升后下降;蓝藻细菌属(Acaryochloris)、未分类的红螺菌属(Rhodospirillaceae_nclassified)、农杆菌属(Agrobacterium)、鞘氨醇单胞菌属(Sphingomonas)等原核微生物属的相对丰度随着醋酸发酵的进行呈下降趋势。总酸由0.61%(以乙酸计)上升至5.35%(以乙酸计),乙醇由5.78%下降至0.33%;还原糖和乳酸含量均呈先上升后下降的趋势。主坐标分析将醋醅样品按照发酵天数聚在一起,并随着发酵的进行在第一主坐标轴上移动;聚类分析将发酵过程分为前期(第0~3天)、中期(第6~12天)和末期(第15天)这3个阶段;相关性分析表明乳杆菌属(Lactobacillus)主要与乳酸和还原糖含量呈正相关,醋杆菌属(Acetobacter)、柠檬乳杆菌属(Limosilactobacillus)、葡糖醋杆菌属(Gluconacetobacter)和醋酸乳杆菌属(Acetilactobacillus)主要与酸度呈正相关,而农杆菌属(Agrobacterium)、黄单胞菌属(Xanthomonas)和甲基杆菌属(Methylobacterium)等菌属主要与酸度呈负相关,且与乙醇含量呈正相关。该研究对揭示赤水晒醋的发酵规律和解析赤水晒醋的发酵机理具有重要意义。

To study the changes in the prokaryotic microbial community structure during acetic acid fermentation of Chishui sun-dried vinegar,high-throughput sequencing was used to analyze the composition of the prokaryotic microbial community in Cupei(vinegar starter),and the changes of basic physicochemical indicators(total acid,ethanol,reducing sugar and lactic acid)of acetic acid fermentation were tested,and the correlation between the physical and chemical factors and the prokaryotic microbial genera were analyzed.The relative abundances of Acetilactobacillus and Gluconacetobacter increased from 0.11%and lower than 0.01%,to 36.78%and 4.76%during acetic acid fermentation,and the relative abundance of Lactobacillus and Acetobacter increased first and then decreased.The relative abundance of Acaryochloris,Rhodospirillaceae_unclassified,Agrobacterium and Sphingomonas showed a downward trend with acetic acid fermentation.The total acid increased from 0.61%to 5.35%(calculated by acetic acid),and the ethanol decreased from 5.78%to 0.33%;the content of reducing sugar and lactic acid both increased first and then decreased.The principal coordinate analysis clusters the Cupei samples together according to the fermentation times,and moved on the first principal coordinate axis along with the fermentation progress;cluster analysis divided the fermentation into three stages:the early(day 0-3),middle(day 6-12)and final stage(the 15^(th) day).Correlation analysis showed that Lactobacillus was mainly positively correlated with the content of lactic acid and reducing sugar;Acetobacter,Limosilactobacillus,Gluconacetobacter and Acetilactobacillus were mainly positively correlated with acidity;while Agrobacterium,Xanthomonas and Methylobacterium were mainly negatively correlated with acidity and positively correlated with ethanol content.This research is of great significance to reveal the law of fermentation and analyze the fermentation mechanism of Chishui sun-dried vinegar.