FIG. 2.

Cell concentration in cells per milliliter (triangles) and mean cell volume in cubic micrometers (circles) of N. winogradskyi in continuous culture with 100% biomass retention (r_s = 1.42 mmol of NaNO₂ h⁻¹). Cells were batch grown during the first 80 h. From 1,100 h onwards, the biomass concentration remained at ca. 332 mg (dry weight) per liter. The ratio of r_s to steady-state biomass concentration reflects a maintenance energy demand (m) of 4.3 μmol of NO₂⁻ per mg (dry weight) per hour. The results of the longest of three similar experiments are shown.