Relative levels of peuA mRNA, assessed by RT-qPCR.

Total RNA samples were prepared from VPD54 (vctA- and irgA-deficient mutant derived from VPD5) and VPD102 (peuRS-deficient mutant derived from VPD54) grown at pH 7.0 and 8.0 in LB-Tris, LB-Tris/+EDDA, and LB-Tris/+EDDA/+Ent media. Data are shown as means ± SD from 3 separate experiments. An asterisk indicates P<0.05 compared to other samples.