FIG. 4.
Role of Stx1 promoter on Stx1 production in EHEC. Overnight cultures grown in LB broth were diluted 1:200 in LB broth and grown for 3 h at 37°C, and then mitomycin C (mito; final concentration, 500 ng/ml) was added at mid-log phase. Further growth was allowed for 5 h at 37°C until the early stationary phase. EHEC strains were fractionated into supernatant (S) and cell-associated (P) fractions. The samples were analyzed by SDS-PAGE and immunoblotting using anti-Stx1 antiserum. Strain characteristic: KP, Δstx1 promoter; K24(−), ΔQ-stx1 (Fig. 2).