非热等离子体ROS效应诱导S. aureus形成VBNC状态的分子机制研究

细菌处于活的不可培养（VBNC）状态时无法用常规培养方法检出，但却具有在适宜条件下复苏的能力，因此被认为是威胁食品安全的“隐性污染源”。作为新兴非热杀菌技术，非热等离子体（NTP）在保障杀菌效果的同时，可有效维持食品的品质和营养。申请人前期研究发现，NTP激发产生的ROS可诱导S. aureus形成VBNC状态，但其分子机制尚不明确。针对这一科学问题，本项目以S. aureus为研究对象，系统考察NTP-ROS效应诱导形成的VBNC状态S. aureus的生物学特性，综合运用转录组学、蛋白组学和生物信息学分析VBNC状态S. aureus的差异表达基因和蛋白，并通过构建突变体对差异基因和蛋白进行功能学验证，系统揭示NTP-ROS效应诱导S. aureus形成VBNC状态的分子机制，为进一步优化NTP杀菌工艺、保障NTP加工食品的安全性奠定理论基础。

The viable but nonculturable (VBNC) bacteria cannot be detected by conventional cultivation methods, but it may be able to recover under optimal conditions. Therefore, the bacteria in VBNC state are considered as “recessive pollutant source” which have potential risk to public health. As a novel nonthermal sterilization technique, nonthermal plasma (NTP) is able to guarantee the bactericidal efficacy and maintain the food quality and nutrition. Our previous study found that the reactive oxygen species (ROS) produced by NTP could induce S. aureus to enter into the VBNC state, while the induction mechanisms are still not clear. In this project, the biological characteristics and molecular regulation mechanisms of VBNC S. aureus cells induced by NTP-ROS will be investigated by comprehensive transcriptomics, proteomics, and bioinformatics methods. The mutants of S. aureus will be constructed to verify the functions of differentially expressed genes and proteins in order to further identify the key regulatory factors. The achievements from this project will provide valuable theoretical basis to inhibiting the formation of VBNC S. aureus cells during the NTP processing, and also help optimize NTP sterilizing technology to guarantee food safety.