The impact of exposure to excess zinc on the transcriptome of Streptococcus mutans

Zinc is a micronutrientient that serves as an important co-factor necessary for enzymatic function. In the host environment, access to metals can be highy restricted. As excess metals can be toxic to the bacterial cell, the host immune system can utilize zinc intoxication as a defense mechanism against bacterial infection. Here, we wanted to identify the transcriptomic response when S. mutans UA159 is exposed to an excess of zinc. Overall design: Streptococcus mutans UA159 was grown in the chemically defined medium FMC. Cultures were grown to mid-exponential phase (OD600 = 0.4). At this point, control samples were harvested for transcriptional profiling. To the remaining samples, 4mM ZnSO4 was added. The incubation of cells was continued to allow for exposure to the excess zinc for 15 or for 90 minutes, at which point these samples were harvested.

锌是一种微量元素，作为酶发挥功能所必需的重要辅因子。在宿主环境中，金属元素的可获得性往往受到严格限制。由于过量金属会对细菌细胞产生毒性，宿主免疫系统可通过锌中毒作为对抗细菌感染的防御机制。本研究旨在探究变形链球菌（Streptococcus mutans，简称S. mutans）UA159暴露于过量锌时的转录组响应。
实验设计：将变形链球菌UA159接种于化学成分限定培养基FMC中进行培养。待培养至指数生长中期（OD600=0.4）时，收集对照样本用于转录组分析。向剩余培养物中添加4mM硫酸锌（ZnSO4），继续培养使细胞分别暴露于过量锌环境15分钟或90分钟，随后收集对应样本。