FIG. 1.

Growth of S. cerevisiae BY4741 is inhibited in the presence of citric acid. (a) Cultures of S. cerevisiae BY4741 were grown to late exponential phase in ME medium alone (pH 3.5) and in the presence of 200, 300, and 400 mM citric acid (CA). (b) Serial dilutions of mid-exponential-phase cultures of S. cerevisiae BY4741 were spotted onto ME agar plates at pH 3.5 with and without the presence of 200, 300, and 400 mM citric acid. Plates were incubated for 48 h at 30°C before the plates were photographed.