Figure 3. Effect of the pH on the r/r_max ratio (apparent maximum specific rate/maximum specific rate at the optimum pH) of nitrite reduction (C/N = 10, 37ºC) at initial nitrate concentrations of 80 mg NO₃^--N L^-1 and 10 mg NO₃^--N L^-1. (-¾). Fitting of the experimental data by the Michaelis function (R² = 0.97).