Germination of Spores of Astrobiologically RelevantBacillusSpecies in High-Salinity Environments
| Autor: | Katja Nagler, Christina Julius, Ralf Moeller |
|---|---|
| Rok vydání: | 2016 |
| Předmět: |
Spores
0301 basic medicine Salinity Extraterrestrial Environment Salt stress 030106 microbiology High salinity Bacillus species Germination Bacillus subtilis Environment Biology 03 medical and health sciences NaCl Microbial ecology Exobiology Botany Environmental Microbiology Spore germination Inhibition Spores Bacterial fungi Space Flight biology.organism_classification Agricultural and Biological Sciences (miscellaneous) Spore Space and Planetary Science Extraterrestrial life |
| Zdroj: | Astrobiology. 16:500-512 |
| ISSN: | 1557-8070 1531-1074 |
| DOI: | 10.1089/ast.2015.1419 |
| Popis: | In times of increasing space exploration and search for extraterrestrial life, new questions and challenges for planetary protection, aiming to avoid forward contamination of different planets or moons with terrestrial life, are emerging. Spore-forming bacteria such as Bacillus species have a high contamination potential due to their spores' extreme resistance, enabling them to withstand space conditions. Spores require liquid water for their conversion into a growing cell (i.e., spore germination and subsequent growth). If present, water on extraterrestrial planets or moons is likely to be closely associated with salts (e.g., in salty oceans or brines), thus constituting high-salinity environments. Spores of Bacillus subtilis can germinate despite very high salt concentrations, although salt stress does exert negative effects on this process. In this study, germination and metabolic reactivation ("outgrowth") of spores of five astrobiologically relevant Bacillus species (B. megaterium, B. pumilus SAFR-032, B. nealsonii, B. mojavensis, and B. vallismortis) in high salinity (≤3.6 M NaCl) were investigated. Spores of different species exhibited different germination and outgrowth capabilities in high salinity, which strongly depended on germination conditions, especially the exact composition of the medium. In this context, a new "universal" germination trigger for Bacillus spores, named KAGE (KCl, L-alanine, D-glucose, ectoine), was identified, which will be very useful for future comparative germination and outgrowth studies on different Bacillus species. Overall, this study yielded interesting new insights on salt stress effects on spore germination and points out the difficulty of predicting the potential of spores to contaminate salty environments on extraterrestrial celestial bodies.Bacillus species-Spores-Germination-High salinity-Salt stress-NaCl-Inhibition. Astrobiology 16, 500-512. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|