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. 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.