FIG. 3.

Effect of different concentrations of ammonium (A) or methylammonium (B) on the growth rate constant μ of S. cerevisiae. (A) Strain 23344c (wild type) was grown in medium 164 buffered with 50 mM Tris, pH 7.5, with glucose (3%) as the carbon source and NH₄Cl as the sole nitrogen source. (B) Strains 23344c (wild type; squares) and 31019b (Δmep1 Δmep2 Δmep3; circles) were grown in medium 164 buffered with 50 mM Tris, pH 7.0, with glucose (3%) as the carbon source and glutamate (10 mM) as the sole nitrogen source.