High Tolerance of to Sodium Perchlorate.

On Mars, significant amounts (0.4-0.6%) of perchlorate ions were detected in dry soil by the Phoenix Wet Chemistry Laboratory and later confirmed with the Mars Science Laboratory. Therefore, the ability of , a desiccation tolerant bacterium, to survive and grow in the presence of perchlorates was determined. Results indicated that was able to tolerate concentrations of sodium perchlorate up to 200 mM ( 1.6%) during cultivation without any changes in its growth pattern. After the addition of up to 440 mM ( 3.7%) sodium perchlorate, showed significant changes in cell morphology; from single motile short rods to long cell chains up to 80 cells. Furthermore, it was shown that the known desiccation tolerance of is highly influenced by a pre-treatment with different perchlorates; additive effects of desiccation and perchlorate treatments are visible in a reduced survival rate. These data demonstrate that thermophiles, especially , have so far, unknown high tolerances against cell damaging treatments and may serve as model organisms for future space experiments.