FIGURE 1.

Growth of dhppz1 mutant in the presence of toxic cations. A, 5 μl of 10-fold serial dilutions of logarithmic phase culture of D. hansenii strains DBH9 (wild type) and DBH91 (dhppz1) were spotted on YPD plates supplemented with different concentrations of LiCl and NaCl. Growth on plates was observed after 2 days of incubation at 28 °C. B, saturated cultures of DBH9 and DBH91 grown in YPD medium were re-inoculated (at initial A₆₀₀ of 0.025) into 50 ml of YPD medium at different pH values containing different concentrations of NaCl. After 24 h of growth at 28 °C, the A₆₀₀ of these cultures was measured. Relative growth of the culture at each concentration of salt was expressed as the percentage of the growth measured in the absence of added salt at same pH. Data presented are the results of three independent experiments (mean ± S.D.). C, shown is dilution spotting of DBH9 and DBH91 on YPD plates containing different amounts of hygromycin and spermine. Results are representative of three independent experiments.