FIG 1.

Sensitivity to tBOOH after oxygen exposure. (A) B. fragilis IB-101 was exposed to 55 mM tBOOH either under anaerobic incubation or 6 h of aerobic incubation prior to anaerobic incubation. No zone of inhibition is visible in the assays that received aerobic incubation. (B) B. fragilis strains IB-101 and ATCC 25285 were exposed to 55 mM tBOOH in a disk diffusion assay, and zones of inhibition were measured. Dark gray bars represent cells that were exposed to air for 6 h prior to anaerobic incubation. Light gray bars represent assays that were not exposed to air. (C) Sensitivity of IB-101 exposed to 55 mM tBOOH in disk diffusion assays where time of aerobic incubation was varied. Data are representative of triplicate assays performed over two independent experiments; averages and standard deviations are shown.