Figure 7.

Visualization of S. typhimurium curli expression in response to changing growth conditions. S. typhimurium 14028 wild-type, ΔrpoS or ΔiraP reporter strains containing a csgBAC promoter–luciferase fusion were transformed with pBR322 (vector), pACYC/rpos (rpoS), pBR322/stm1987 (stm1987) or pBR322/yhjH (yhjH) plasmids. Cells were inoculated onto T agar or T agar supplemented with 0.2% glucose, 25 mM or 100 mM NaCl and grown at 28 °C or 37ºC. Colony morphology (left column) and luminescence (right column) was recorded after 48 h growth. Control strains containing pACYC were also tested, but the csgBAC expression profiles were similar to strains transformed with pBR322; therefore, only the pBR322 pictures are shown.