豆酱不同发酵阶段细菌群落多样性及动态变化分析

以东北传统自然发酵豆酱为研究对象,采用聚合酶链式反应-变性梯度凝胶电泳(polymerase chain reactiondenaturing gradient gel electrophoresis,PCR-DGGE)技术结合高通量测序方法分析豆酱发酵过程中细菌的多样性及动态变化。结果显示,细菌的可操作分类单元数值在发酵过程中上下波动,并在后发酵第21天时达到最大值,此时细菌数目最多;整理分析PCR-DGGE图谱鉴定结果以及细菌在属水平上的分布得出,明串珠菌属、肠球菌属、四联球菌属和乳杆菌属为豆酱样品不同发酵阶段的优势细菌菌属,其中四联球菌属波动性较大,易受内外环境的影响;屎肠球菌、明串珠菌属、绿色魏斯菌随着发酵时间的延长在减少,说明这些细菌主要参与豆酱发酵初期产酶分解物质过程,并在整个发酵过程中起到调整发酵内环境等作用。

Diversity and Dynamic Changes of the Bacterial Community during Fermentation of Soybean Paste

In this study, the diversity and dynamic changes of?the bacterial community during the natural fermentation of soybean paste, a traditional fermented food popular in northeast China, were analyzedusing polymerase chain reaction-denaturing gradient gel electrophoresis (PCR-DGGE) technology and high-throughput sequencing. Results showed that bacterial operational taxonomy unit (OTU) values were fluctuant during the fermentation and reached a maximum on day 21, indicating the largest bacterial population. Analysis of DGGE profiles and the distribution of bacteria at the genus level suggested that Leuconostoc sp., Enterococcus sp., Tetragenococcus sp. and Lactobacillus sp. were predominant bacterial strains for different fermentation stages of soybean paste. Among these, Tetragenococcus sp. was more fluctuant and and vulnerable to both internal and external environments. Enterococcus faecium, Leuconostoc sp. and Weissella viridescens decreased with fermentation time indicating that these bacteria might be mainly involved in the production of catabolic enzymes in the early fermentation stage and played a role in the adjustment of the internal environment during the whole fermentation process.