FIG. 3.

Growth of B. suis strains and nitrite accumulation under microaerobic conditions. Each strain was previously grown under aerobiosis until an optical density of approximately 0.25 was reached. Wild-type (•) and cydB (▴) mutant bacteria were then cultivated in TS medium supplemented or not (corresponding open symbols) with 10 mM NaNO₃, in a jar containing GENbox generators of microaerobic atmosphere. At various time points, an aliquot was collected to measure the optical density at 600 nm (A) and centrifuged to measure nitrite concentration in the supernatant (B). The narG (▪) strain was used as a negative control of nitrite production.