FIG 2.
The ΔentF mutant can grow in low-iron medium when in coculture with the wild type. E. coli BW25113 arsB::kan (WT1) or ΔentF arsB::kan (ΔentF) was mixed at a 1:1 ratio with E. coli BW25113 arsB::cat (WT2). (A) Competitive index; (B) final cell density. The initial cell density was about 105 cells per ml. Total cells per milliliter and strain frequencies were measured at the start of the experiment and after 14 h. The competitive index was calculated as described in Materials and Methods. Results from three independent experiments are shown, and the bars indicate the means.