Enhanced Microbial Survivability in Subzero Brines
Autor: | Jacob Heinz, Alessandro Airo, Samuel P. Kounaves, Dirk Schulze-Makuch, Janosch Schirmack |
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Rok vydání: | 2018 |
Předmět: |
0301 basic medicine
Sodium 030106 microbiology chemistry.chemical_element Salt (chemistry) Calcium Astronomy & Astrophysics 03 medical and health sciences Perchlorate chemistry.chemical_compound Chlorides ddc:570 Freezing 0402 Geochemistry Planococcus Bacteria Planococcus halocryophilus chemistry.chemical_classification Microbial Viability Perchlorates Magnesium Osmolar Concentration Water Agricultural and Biological Sciences (miscellaneous) Halophile Freezing point Cold Temperature 0201 Astronomical And Space Sciences 030104 developmental biology chemistry 0403 Geology 13. Climate action Space and Planetary Science Environmental chemistry ddc:520 Salts |
Zdroj: | Astrobiology. 18(9) |
ISSN: | 1557-8070 |
Popis: | It is well known that dissolved salts can significantly lower the freezing point of water and thus extend habitability to subzero conditions. However, most investigations thus far have focused on sodium chloride as a solute. In this study, we report on the survivability of the bacterial strain Planococcus halocryophilus in sodium, magnesium, and calcium chloride or perchlorate solutions at temperatures ranging from +25°C to −30°C. In addition, we determined the survival rates of P. halocryophilus when subjected to multiple freeze/thaw cycles. We found that cells suspended in chloride-containing samples have markedly increased survival rates compared with those in perchlorate-containing samples. In both cases, the survival rates increase with lower temperatures; however, this effect is more pronounced in chloride-containing samples. Furthermore, we found that higher salt concentrations increase survival rates when cells are subjected to freeze/thaw cycles. Our findings have important implications not only for the habitability of cold environments on Earth but also for extraterrestrial environments such as that of Mars, where cold brines might exist in the subsurface and perhaps even appear temporarily at the surface such as at recurring slope lineae.It is well known that dissolved salts can significantly lower the freezing point of water and thus extend habitability to subzero conditions. However, most investigations thus far have focused on sodium chloride as a solute. In this study, we report on the survivability of the bacterial strain Planococcus halocryophilus in sodium, magnesium, and calcium chloride or perchlorate solutions at temperatures ranging from +25°C to −30°C. In addition, we determined the survival rates of P. halocryophilus when subjected to multiple freeze/thaw cycles. We found that cells suspended in chloride-containing samples have markedly increased survival rates compared with those in perchlorate-containing samples. In both cases, the survival rates increase with lower temperatures; however, this effect is more pronounced in chloride-containing samples. Furthermore, we found that higher salt concentrations increase survival rates when cells are subjected to freeze/thaw cycles. Our findings have important implications not only for the habitability of cold environments on Earth but also for extraterrestrial environments such as that of Mars, where cold brines might exist in the subsurface and perhaps even appear temporarily at the surface such as at recurring slope lineae. |
Databáze: | OpenAIRE |
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