Supplementary Materials.docx

<b><i>Interpretive Summary</i></b><i>Streptococcus thermophilus</i><i> </i>is regarded as a safe strain and routinely subjected to a variety of harsh circumstances throughout the manufacturing process. Among these stresses, oxidization is the most lethal for <i>S. thermophilus</i>. It was demonstrated that CovRst was able to bind to the <i>efeB</i> and <i>gshF</i> gene promoter regions. These two genes were upregulated as a result of the deletion of the <i>covRst</i> gene. When viewed in conjunction with the extracellular GSH level and survivability data, it was determined that CovRst functions as a negative regulator of <i>S. thermophilus</i> oxidative stress response. This result provides theoretical support for its production.

【解读性摘要】嗜热链球菌（*Streptococcus thermophilus*）被公认为安全菌株，其在生产工艺过程中会持续暴露于多种严苛环境胁迫之中。在各类胁迫因素里，氧化胁迫对嗜热链球菌的致死效应最为显著。研究证实，CovRst可结合*efeB*与*gshF*基因的启动子区域；*covRst*基因缺失后，这两个基因的表达量显著上调。结合细胞外谷胱甘肽（GSH）水平与存活率数据综合分析，可确定CovRst是嗜热链球菌氧化应激应答的负调控因子。该研究结果为嗜热链球菌的规模化生产提供了理论支撑。