FIG 5.

Enterobactin cannot rescue the ΔmacAB mutant from peroxide-mediated death. (A and B) Overnight cultures of the wild-type strain (A) or the ΔmacAB mutant (B) were subcultured at 1/100 in peroxide-containing LB or in 1 mM H₂O₂ with LB additionally supplemented with 2.5 μM enterobactin and incubated at 37°C with aeration. Aliquots were collected hourly, serially diluted, and plated for CFU enumeration. Data are presented as mean survival results from at least three independent experiments. The asterisk indicates significance in Student’s t test with P values of <0.05.