Figure 1.

Illustration of the ALE process. Rhodopseudomonas palustris CGA009 was anaerobically cultured in 10 mL PM medium at 30°C under the incandescent lamp, using 20 mM NaAc as a carbon source and 1.5% salt concentration. The culture in the logarithmic phase was further transferred to a fresh medium. After every three generations, the salt concentration in the medium was increased by 0.2%. After 8 months of culture, the salt concentration was increased to the final 4% and stabilized for about 10 generations. The single colonies were isolated and screened for salt tolerance by growth curve.