The impact of H2O2 exposure on the transcriptome of Streptococcus mutans wild type and perR mutant strains

H2O2 is an oxidative stress agent known to trigger an upregulation in expression of detoxification genes in Streptococcus mutans. Following discovery of a spontaneously-occurring perR mutation, we wanted to compare the transcriptomic responses of H2O2 exposure in S. mutans strains bearing an intact perR or a perR deletion. Streptococcus mutans UA159 was grown in BHI medium to mid-exponential phase (OD600 = 0.4). At this point, the samples were split into two equal volumes. One volume was reserved as the control; H2O2 was added to the stressed volume to 0.5mM. The cultures were incubated at 37C, 5% CO2 for an additional 5 minutes. Cells were then harvested by centrifugation (4000 RPM, 10 minutes). RNA was isolated using the Qiagen RNeasy Mini Kit, and RNA from control and H2O2-stressed samples was prepared for RNA-Seq analysis.