Figure 15. Expression of P. gingivalis HmuY and T. forsythia Tfo during bacterial growth.

(A) Relative changes in levels of transcripts in bacteria grown under low- compared with high-iron/heme conditions at indicated time points at the first (I) and second (II) passage as determined by RT-qPCR are shown. (B) Bacteria were grown in liquid culture media under high- (Hm) or low-iron/heme (DIP) conditions for 24 h and both whole cultures and bacterial cells were subjected to centrifugation and/or ultracentrifugation. To enable visualization of the soluble HmuY and Tfo by immunoblotting, the culture media were concentrated 25× by ultrafiltration. Abbreviations: OMV, outer membrane vesicles; SP, soluble protein shed from bacterial outer membrane; WC, whole bacterial cell.