Figure 2.

Growth characteristics in the absence of the SapF ATPase. The parent strain (circle) and SapF-deficient strain (square) were grown overnight on chocolate agar, diluted in DIS medium, matched for optical density (OD₄₉₀) and inoculated into DIS medium containing 2 μg heme/mL (A). Growth was assessed by measuring the OD₄₉₀ every hour for 5 h. Error bars represent the standard deviation of the mean of cultures assayed in triplicate from three independent assays (n = 2). (B) The parental strain (black bar), the SapF-deficient strain (white bar), and the complemented SapF-deficient strain (gray bar) were incubated in DIS medium in the absence of heme-iron for 16 hours. The resultant cultures were matched for optical density (OD₄₉₀) and plated for number of CFU. ^*denotes p < 0.05 by a two-tailed Student's t-test (N = 5).