FIGURE 2.

Effects of Mg²⁺ and K⁺ on the growth of Zymomonas mobilis TISTR 548 at critical high temperatures. Cells were cultivated in YPD medium with several concentrations of MgCl₂ (A: closed circle, 0 mM; open circle, 5 mM; open diamond, 10 mM; open square, 20 mM; and open triangle, 40 mM) and KCl (B: closed circle, control, 0 mM; open circle, 10 mM; open diamond, 20 mM; open square, 50 mM; open triangle up, 100 mM; and open triangle down, 200 mM) at 39°C under a static condition. At 39°C (C) and 39.5°C (D), 5 mM MgCl₂ (open circle), 30 mM KCl (open diamond), and a combination of these metals (open square), were added, and two-step cultivation was performed. Values and error bars represent means and standard deviations, respectively, for triplicate cultures.