低盐传统泡菜微生物多样性及其对亚硝酸盐和亚硝胺形成的内在作用机制

亚硝酸盐和亚硝胺风险是传统发酵食品共同面对的重大安全课题。低盐化生产是传统发酵蔬菜制品重要的发展方向之一。本项目以低盐传统泡菜为研究对象，结合传统微生物培养方法与高通量宏基因组测序技术分析不同发酵类型、不同发酵阶段的泡菜微生物多样性以及亚硝酸盐和亚硝胺的代谢途径，构建泡菜主要优势菌及亚硝酸盐和亚硝胺特征指示菌的分子指纹图谱，探究优势菌与特征指示菌间的生态关系，并在此基础上剖析亚硝酸盐和亚硝胺形成关键酶的合成与活性在泡菜微生态中的调控机制，在微生物群落结构水平和代谢调控水平上揭示低盐泡菜中亚硝酸盐和亚硝胺的形成机理，为传统发酵蔬菜生产中亚硝酸盐和亚硝胺风险控制奠定理论基础。

Nitrite and nitrosamine risks are considered as significant food safety issues in traditional fermented foods. Meanwhile, low-salt production of traditional fermented vegetables is a promising direction. In this study, the microbial diversity of low-salt Chinese paocais and the metabolic pathways of nitrite and nitrosamine were studied by using culture-dependent method and culture-independent methods including macro genome sequencing. The molecular fingerprints of the dominant bacteria in paocais and the specific indicator bacteria (SIB) of nitrite and nitrosamine formation were then developed, and their ecological relationship was investigated. Furthermore, the regulatory mechanism on the key enzymes of nitrite and nitrosamine formation was studied. Based on the data above, the formation mechanisms of nitrite and nitrosamine in low-salt Chinese paocai were discussed on the levels of microbial community composition and metabolism regulation. This study would lay theoretical basis for the risk control of nitrite and nitrosamine formation in Chinese fermented vegetables.