The bacterial community structure in 29 naturally fermented samples of sunki, an unsalted lactic-fermented pickle in Japan, was determined by 16S rRNA gene-targeted metagenomic analysis. The data revealed that genus Lactobacillus was dominant in all samples and various bacterial species, related to Lactobacillus delbrueckii, Lactobacillus plantarum, Lactobacillus buchneri, Lactobacillus fermentum, Lactobacillus reuteri, Lactobacillus crispatus, Lactobacillus intestinalis, and Lactobacillus gasseri, showed a range of dominance depending on the samples. Comparative analysis of the bacterial composition by principal coordinate analysis and hierarchical clustering classified the varied bacterial composition of the 29 samples into three types of bacterial community structure. These types comprised lactobacilli belonging to different phylogenetic groups: type A had a certain ratio of Lactobacillus fermentum (70.3–22.1%, average 41.2%) in combination with several species belonging to Lactobacillus delbrueckii-phylogenetic group, type B comprised remarkably high levels of species Lactobacillus delbrueckii (average 89.5%), and type C had combinations of species belonging to Lactobacillus plantarum- and Lactobacillus buchneri-phylogenetic groups. Interestingly, these types differed in the compositional profiles of water-soluble and volatile compounds, and statistically significant differences were observed in the levels of acetic acid, succinic acid, ethanol, ethyl acetate, glutamic acid, γ-aminobutyric acid, and isovaleraldehyde. Furthermore, metabolomic analysis revealed a correlation of Lactobacillus fermentum dominance with pH value and lactic and acetic acid levels, with high R values of 0.643, −0.642, and 0.528, respectively. The data reported in this study showed the characteristics of the bacterial composition in the unsalted sunki pickle and its potential relationship with the compositional profile.

通过16S rRNA基因靶向的宏基因组学分析确定了29个自然发酵的sunki样品的细菌群落结构，sunki是日本未腌制的乳酸发酵咸菜。数据显示，属乳杆菌是所有样品和各种细菌物种中占主导地位的，关系到德氏乳杆菌，植物乳杆菌，布氏乳杆菌，发酵乳杆菌，罗伊氏乳杆菌，卷曲乳杆菌，乳杆菌肠，和格氏乳杆菌，显示出一定的优势范围，具体取决于样品。通过主坐标分析和层次聚类对细菌组成进行比较分析，将29个样品的不同细菌组成分为三种类型的细菌群落结构。这些类型包括属于不同系统发育组的乳杆菌：A型具有一定比例的发酵乳杆菌（70.3–22.1％，平均41.2％），并结合了德氏乳杆菌-系统发育组的几种菌种，而B型则包含很高水平的菌种德氏乳杆菌（平均89.5％）和C型具有植物乳杆菌属的物种组合-和布氏乳杆菌系统发生群。有趣的是，这些类型的水溶性和挥发性化合物的组成特征不同，并且在乙酸，琥珀酸，乙醇，乙酸乙酯，谷氨酸，γ-氨基丁酸和异戊醛的含量上观察到统计学上的显着差异。此外，代谢组学分析显示发酵乳杆菌优势度与pH值以及乳酸和乙酸水平相关，R值分别为0.643，-0.642和0.528。这项研究报告的数据显示了无盐酱油腌菜中细菌成分的特征及其与成分分布的潜在关系。