EFFECTS OF ANCIENT ROCK SALT ON HALOARCHAEAL GROWTH: HALOPHILES AS POSSIBLE MODEL ORGANISMS FOR EXO-/ASTROBIOLOGICAL RESEARCH

摘要

Halococcus dombrowskii was described as a novel haloarchaeal species isolated from Alpine rock salt which is believed to have been deposited about 250 million years ago. During its characterization, a new medium (M2S) was created by addition of dissolved and sterile-filtered rock salt to standard halophile medium (M2), which showed a pronounced growth stimulating effect on halococcal strains. Cultures grown in M2S had lower doubling times and reached a greater turbidity compared to cultures grown in M2. In addition, changes in cell morphology and significant differences in whole cell protein patterns were observed. It was examined whether this stimulating effect is reproducible within other halobacterial genera. M2S medium appears to approach the composition of the natural habitat of halophilic archaea and is therefore of interest for astrobiological research.