FIG 8.

Citrulline protection of the wild type is sensitive to DCCD. Wild-type bacteria were cultured with arginine or citrulline at 10 mM (A) or 20 mM (B) at 37°C for 24 h. Following this growth period, cultures were removed, and either 1 mM DCCD (+) or the vehicle ethanol (−) was added. The cultures were then placed back at 37°C for an additional 5 days. The bacterial viabilities of the cultures were then measured as previously described. Differences in CFU were tested for significance between the designated growth conditions using the Mann-Whitney U test (**, P < 0.05). n.s., not significant.