Growth and lysis of BL21(DE3)/pUTaBE induced under iron-limiting conditions. (A) Growth and lysis (solid symbols) and viable cell counts (open symbols) of E. coli grown in LB. BL2(DE3)/pUTa with 2,2′-dipyridyl induction (diamonds), BL21(DE3)/pUTaBE with 2,2′-dipyridyl induction (circles), and BL21(DE3)/pUTaBE without 2,2′-dipyridyl induction (triangles) are shown. At 0 min, 2,2′-dipyridyl was added (↓). Standard deviations were calculated from the results from three independent experiments. (B) Scanning electron micrographs of E. coli BL21(DE3)/pUTa (without gene E) with 2,2′-dipyridyl addition (panel I) and of E. coli BL21(DE3)/pUTaBE (with gene E) without 2,2′-dipyridyl addition (panel II) and at 30 min (panel III) and 2 h (panel IV) after 2,2′-dipyridyl addition.