天津独流老醋醋酸发酵过程中细菌群落多样性及动态变化研究

本论文采用PCR-DGGE方法对天津独流老醋醋酸发酵过程细菌群落组成以及其多样性变化进行了研究,重点比较了独流老醋醋酸发酵阶段上下层醋醅中细菌群落组成之间的差异。独流老醋上下层醋醅中均检测到13种细菌,虽然独流老醋在醋酸发酵阶段只对上层的醋醅进行翻醅操作,由于上、下层醋醅仍处于同一发酵体系,细菌的组成一致,但两个区域细菌群落的多样性存在差异。聚类分析将细菌群落组成分为第一阶段和第二阶段两类,Shannon指数表明独流老醋醋酸发酵第一阶段醋醅中细菌多样性高于第二阶段醋酸发酵,而上层醋醅中细菌多样性略高于下层醋醅。巴氏醋杆菌(Acetobacter pasteurianus)是醋酸发酵阶段将乙醇氧化为醋酸的主要微生物,随着发酵的进行丰度逐渐增加,在醋酸发酵后期丰度达到最高。而部分乳酸菌Lactobacillus plantarum、Lactobacillus acetotolerans、等随着发酵的进行丰度逐渐增加,可能与其较强的耐酸性有关。

Analysis of the Diversity and Change in Dynamics of Bacterial Communities during Acetic Acid Fermentation of Tianjin Duliu Mature Vinegar

The polymerase chain reaction/denaturing gradient gel electrophoresis (PCR-DGGE) was used to explore the diversity and change in dynamics of the bacterial communities during AAF of TDMV. In particular, the bacterial communities in the vinegar pei from the top and bottom layers were compared. Thirteen genera of bacteria were detected in the vinegar pei of the two layers. Although only the vinegar pei in the upper layer was stirred manually every day during the production process, the two layers of pei still belonged to the same system and the bacterial compositions were consistent, but there were differences in the diversity of the bacterial communities in the two layers. Using cluster analysis, the bacterial compositions were divided into two groups: the first stage and the second stage. According to the Shannon index, the diversity of bacteria from the first stage was higher than that of the second stage, and the diversity of bacteria in the upper layer was slightly higher than that of the bottom layer. The abundance of Acetobacter pasteurianus, the main microorganism converting ethanol to acetic acid in the AFF, increased gradually during the fermentation process and reached a peak value at the end of the fermentation. The abundance of some lactic acid bacteria (LAB), including Lactobacillus plantarum and Lactobacillus acetotolerans, increased gradually over the fermentation time, likely as a result of their high acid tolerance.