Figure 2. Cell growth and virulence gene expression in B. anthracis 34F2 and 34F2ΔBAS2714-12 under various growth conditions.

For β-galactoside assays, cells carrying a pagA-lacZ or atxA-lacZ fusion on the replicative vector pTCV-lac were grown in medium supplemented with Kanamycin. β-galactosidase assays were carried out on samples taken at hourly intervals as indicated. (A) pagA-lacZ reporter strains grown in LB broth in air at 37°C. (B) pagA-lacZ reporter strains grown in R Media with 0.8% NaHCO₃ under 5% CO₂ at 37°C. (C) atxA-lacZ reporter strains grown in R Media with 0.8% NaHCO₃ under 5% CO₂ at 37°C. Symbols in all panels: -□- 34F2 cell growth; -○- 34F2ΔBAS2714-12 cell growth; -▪- 34F2 LacZ expression; -•- 34F2ΔBAS2714-12 LacZ expression.