FIG. 3.

ETB production in TY825 and in its regulator mutants. (A and B) Western blot (A) and SDS-PAGE (B) analyses of ETB production in wild-type strain and its saeR (FK204), arlR (FK206), and agrC (FK211) isogenic mutants. M, molecular mass markers. (C and D) Western blot (C) and SDS-PAGE (D) analyses of ETB production in the wild-type strain and its sigB (FK216), sarA (FK218), and sarS (FK217) isogenic mutants. Cells were grown in TSB with shaking at 37°C for 15 h, and culture supernatants were harvested by centrifugation. The concentration of ETB was detected by Western immunoblotting with anti-ETB antiserum, as described in Materials and Methods. The intensity of each band was measured by NIH Image and quantified relative to that of the parental strain, TY825. The data presented are mean values from three independent experiments. Error bars denote standard deviations.