Fig. 5.

B. fragilis Δoxe is more aerotolerant than WT. ADB77 (■), ADB267 (▲), ADB267/pJST61 (●), and ADB267/pADB293 (◆) cultures were grown anaerobically in BHIS to midlog phase. Cells were pelleted and washed with PBS solution, and then resuspended in 10 mL PBS solution plus thymine and 0.5% glucose in 125-mL foam-stoppered flasks. Flasks were shaken at 37 °C under room air. Samples were serially diluted in PBS solution. Aliquots (10 μL) were spotted to prereduced BHIS plates (with or without erythromycin) and incubated in the anaerobic chamber. Counts (in cfu) were enumerated after 2 d incubation by using a stage microscope. Shown are the means of three experiments ± SEM.