Life from the ashes: survival of dry bacterial spores after very high temperature exposure
Autor: | Johan Mertens, Tom Gheysens, Mohamed Amar, James S. Clegg, Lynda Beladjal |
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Rok vydání: | 2018 |
Předmět: |
0301 basic medicine
Thermotolerance Bacillus amyloliquefaciens DNA damage DNA repair 030106 microbiology Microbiology Endospore 03 medical and health sciences Bacterial Proteins Food science Desiccation Incubation Spores Bacterial biology Chemistry fungi General Medicine biology.organism_classification Spore 030104 developmental biology Germination Amylases Molecular Medicine Dry Heat Sterilization DNA Damage Extreme Environments Peptide Hydrolases |
Zdroj: | Extremophiles : life under extreme conditions. 22(5) |
ISSN: | 1433-4909 |
Popis: | We found that spores of Bacillus amyloliquefaciens rank amongst the most resistant to high temperatures with a maximum dry heat tolerance determined at 420 °C. We found that this extreme heat resistance was also maintained after several generations suggesting that the DNA was able to replicate after exposure to these temperatures. Nonetheless, amplifying the bacterial DNA using BOXA1R and (GTG)5 primers was unsuccessful immediately after extreme heating, but was successful after incubation of the heated then cooled spores. Moreover, enzymes such as amylases and proteases were active directly after heating and spore regeneration, indicating that DNA coding for these enzymes were not degraded at these temperatures. Our results suggest that extensive DNA damage may occur in spores of B. amyloliquefaciens directly after an extreme heat shock. However, the successful germination of spores after inoculation and incubation indicates that these spores could have a very effective DNA repair mechanism, most likely protein-based, able to function after exposure to temperatures up to 420 °C. Therefore, we propose that B. amyloliquefaciens is one of the most heat resistant life forms known to science and can be used as a model organism for studying heat resistance and DNA repair. Furthermore, the extremely high temperature resistivity of these spores has exceptional consequences for general methodology, such as the use of dry heat sterilization and, therefore, virtually all studies in the broad area of high temperature biology. |
Databáze: | OpenAIRE |
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