FIG. 5.

Reversible inhibition of nitrite reductase activity by oxygen. Induced cells (grown anaerobically with 2 mM nitrite) were incubated aerobically (for 10 min [filled circles], and for 60 min [filled triangles]) or anaerobically (for 60 min [open triangles]). After this preincubation, the conditions were switched to anaerobiosis and the ability of the cells to reduce nitrite was measured as nitrite decrease. In parallel, nitrite decrease was detected in the induced cells incubated aerobically (filled squares).