Figure 4

Effect of pH on cell growth and GABA production in flask cultivation of C. glutamicum . (A) Time profiles of cell growth and pH change at four different pH conditions. Triangle, circle and square symbols indicate the pH 4, pH 5 and pH 6, respectively. The open and closed symbols indicate the cell density and pH change, respectively. (B) Time profiles of GABA concentrations during cultivations. Triangle, and circle and square symbols indicate pH 4, pH 5 and pH 6, respectively. Each point represents the average of three independent experiments.