Fig 5. Mutants lacking PepN (ΔpepN) demonstrate the same growth kinetics and capsule levels as wild-type TIGR4.

A) TIGR4 and ΔpepN cells were grown to mid-log phase, back-diluted in fresh media to OD₆₀₀ 0.003, incubated at 37°C and OD₆₀₀ was measured every 30 minutes for 12h. Data presented are the means ± SD from 3 independent experiments. B and C) Capsule was isolated from OD₆₀₀-matched, mid-log phase TIGR4, Δcps and ΔpepN cells. For each strain, 5μL spots of a 2-fold serial dilution were applied to a nitrocellulose membrane, which was developed using an unconjugated rabbit anti-serotype 4 serum, HRP-conjugated goat anti-rabbit antibody and ECL Blotting Substrate. B) Data shown are from one blot representative of 3 independent experiments. C) Data presented are the means ± SD from 3 independent experiments. ***, P<0.001; ns = no significant difference. Statistical analyses were conducted using a one-way ANOVA and Tukey’s Multiple Comparisons Test.