FIG 2.

Resensitization of nongrowing E. coli to NIT. Stationary-phase cultures of E. coli were treated with 250 μg/ml NIT or DMSO (A) or 10 mM glucose with or without 250 μg/ml NIT (B), and absorbance at 375 nm (A₃₇₅) was determined at the indicated time points. (C) Stationary-phase cultures of E. coli were treated with 10 mM glucose with or without 250 μg/ml NIT, and CFU per milliliter were monitored at the indicated time points. *, P < 0.05 (t test), comparing glucose plus NIT at 1, 3, 5, and 7 h with t = 0 in panel B, and glucose with glucose plus NIT in panel C. Data represent at least three biological replicates. Each data point was denoted as mean ± SE. A similar phenomenon was observed when plating on MOPS plus glucose agar rather than LB agar, although the potentiation was slightly less pronounced (see Fig. S16 in the supplemental material).