FIG. 1.

Uptake of nitrite by nitrate (60 mM)-grown cells of NA3 at pH 9.6 and at pH 7.2. Changes in nitrite concentration in the medium after addition of nitrite to the cell suspensions containing 5 μg of Chl per ml are shown. For panel A, the cell suspension was separated into two portions and nitrite uptake was measured with initial nitrite concentrations of ca. 110 (upper curve) and 30 (lower curve) μM. (C and D) Plots of nitrite uptake rate versus nitrite concentration in medium at pH 9.6 and at pH 7.2, respectively. The nitrite uptake rate was calculated as the rate of uptake between each sampling time shown in panels A and B.