Fermented vegetables can be divided into two types, natural fermented and artificially inoculated fermented. By detecting and identifying the changes of bacterial diversity using physical and chemical indicators during natural and inoculation fermentation, we analyzed and determined the dominant bacteria in the fermentation process and revealed the relationship between bacteria and volatile substances. We used the Illumina Miseq to sequence the bacteria in fermented vegetable samples at different fermentation periods, and calculated the total number of mesophilic microorganisms and lactic acid bacteria. We used the pH and nitrite to monitor the acidification process. GC-MS was used to determine volatile flavor compounds. Finally, we analyzed the correlation between volatile flavor compounds and bacteria. Total mesophilic microorganisms and the number of lactic acid bacteria in the inoculated fermentation were higher than the natural fermentation. The bacterial diversity Shannon and Simpson indexes of the natural fermentation, higher than those of inoculated fermentation in 0~7 days, were between 55~71% and 36~45%, respectively. On the 7th day, the proportion of Lactobacillus in the natural fermentation and inoculated fermentation were 53.4% and 90.2%, respectively, which were significantly different. Lactobacillus was the dominant genus in the fermented vegetables and an important genus to promote the formation of volatile flavors. Lactobacillus was negatively correlated with two volatile substances (4-[2,2,6-trimethyl-7-oxabicyclo [4.1.0] hept-1-yl]-3-Buten-2-one (K4) and a-Phellandrene (X1)) and played a leading role in the fermentation process. Results demonstrated that the total number of mesophilic microorganisms and lactic acid bacteria in inoculated fermentation were more than those in natural fermentation. Inoculated fermentation can shorten the fermentation cycle and reduce the content of nitrite. Lactic acid bacteria were the dominant bacteria in fermented vegetables.

中文翻译：

---

山西省自然和接种蔬菜发酵过程中细菌谱和理化特性的差异

发酵蔬菜可分为天然发酵和人工接种发酵两种。通过使用自然和接种发酵过程中的理化指标检测和鉴定细菌多样性的变化，我们分析和确定了发酵过程中的优势细菌，并揭示了细菌与挥发性物质之间的关系。我们使用Illumina Miseq对不同发酵阶段的发酵蔬菜样品中的细菌进行了测序，并计算了嗜温微生物和乳酸菌的总数。我们使用pH和亚硝酸盐监测酸化过程。GC-MS用于测定挥发性风味化合物。最后，我们分析了挥发性风味化合物与细菌之间的相关性。接种发酵中的总嗜温微生物和乳酸菌数量高于自然发酵。自然发酵的细菌多样性香农指数和辛普森指数高于接种0〜7天的菌种，分别在55〜71％和36〜45％之间。第7天，乳酸菌在自然发酵和接种发酵中的比例分别为53.4％和90.2％，差异有统计学意义。乳酸菌是发酵蔬菜中的主要属，并且是促进挥发性风味形成的重要属。乳酸杆菌与两种挥发性物质（4- [2,2,6-三甲基-7-氧杂双环[4.1.0]庚-1-基] -3-丁烯-2-酮（K4）和α-芹菜烯（ X1）），并在发酵过程中起主导作用。结果表明，接种发酵中的嗜温微生物和乳酸菌的总数要多于自然发酵。接种发酵可以缩短发酵周期，减少亚硝酸盐含量。乳酸菌是发酵蔬菜中的主要细菌。