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Translating physics to microbiology: spore resistance to terrestrial and extraterrestrial extremes

Moeller, Ralf and Raguse, Marina and Nagler, Katja and Fuchs, Felix M. (2016) Translating physics to microbiology: spore resistance to terrestrial and extraterrestrial extremes. The 7th European Spores Conference, 18.-20. April 2016, Royal Holloway, University of London, London, England.

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Abstract

Spore-forming bacteria are of particular concern in the context of planetary protection because their tough endospores are capable of withstanding certain sterilization procedures as well as harsh environments. Spores of Bacillus subtilis have been shown to be suitable dosimeters for probing extreme terrestrial and extraterrestrial environmental conditions in astrobiological and environmental studies. During dormancy spores are metabolically inactive; thus substantial DNA, protein, tRNA and ribosome damage can accumulate while the spores are incapable of repairing and/or degrading damaged DNA and proteins. Consequently, damage to essential components of spores poses a unique problem, since damage repair does not occur until the processes of spore revival. Spores appear to have two possible ways to minimize deleterious effects of environmental extremes: (i) by protecting dormant spore macromolecules (in particular the spore DNA) from damage in the first place and (ii) by ensuring repair of damage during spore outgrowth. In our research, we used spores of different genotypes of B. subtilis to study the effects of various extraterrestrial conditions (e.g., planetary conditions as present on Mars or low Earth orbit (LEO)) for astrobiological purposes. Spores of wild-type and mutant B. subtilis strains lacking various structural components were exposed to simulated Martian atmospheric, galactic cosmic and UV irradiation conditions. Spore survival was strongly dependent on the functionality of all of the structural components, with small acid-soluble spore proteins, coat layers, and dipicolinic acid (DPA) as key protectants. In addition, the interaction of several DNA repair mechanisms (e.g., non-homologous end joining (NHEJ) and spore photoproduct (SP) lyase) was identified as crucial for surviving environmental extremes in space or Martian surface (i.e., exposure to solar UV and galactic cosmic radiation. The ultimate goal is to obtain a complete model describing spore persistence and longevity in harsh environments.

Item URL in elib:https://elib.dlr.de/104283/
Document Type:Conference or Workshop Item (Speech)
Title:Translating physics to microbiology: spore resistance to terrestrial and extraterrestrial extremes
Authors:
AuthorsInstitution or Email of AuthorsAuthors ORCID iD
Moeller, RalfGerman Aerospace Center (DLR e.V.), Institute of Aerospace Medicine, Radiation Biology Department, Space Microbiology Research Group, Cologne (Köln), Germany; E-mail: ralf.moeller (at) dlr.deUNSPECIFIED
Raguse, MarinaGerman Aerospace Center (DLR e.V.), Institute of Aerospace Medicine, Radiation Biology Department, Space Microbiology Research Group, Cologne (Köln), GermanyUNSPECIFIED
Nagler, KatjaGerman Aerospace Center (DLR e.V.), Institute of Aerospace Medicine, Radiation Biology Department, Space Microbiology Research Group, Cologne (Köln), GermanyUNSPECIFIED
Fuchs, Felix M.German Aerospace Center (DLR e.V.), Institute of Aerospace Medicine, Radiation Biology Department, Space Microbiology Research Group, Cologne (Köln), GermanyUNSPECIFIED
Date:2016
Refereed publication:Yes
Open Access:Yes
Gold Open Access:No
In SCOPUS:No
In ISI Web of Science:No
Status:Published
Keywords:Spore-forming bacteria, Bacillus subtilis, spore resistance, terrestrial and extraterrestrial extremes, galactic cosmic and UV irradiation conditions
Event Title:The 7th European Spores Conference
Event Location:Royal Holloway, University of London, London, England
Event Type:international Conference
Event Dates:18.-20. April 2016
HGF - Research field:Aeronautics, Space and Transport
HGF - Program:Space
HGF - Program Themes:Research under Space Conditions
DLR - Research area:Raumfahrt
DLR - Program:R FR - Forschung unter Weltraumbedingungen
DLR - Research theme (Project):R - Vorhaben Strahlenbiologie
Location: Köln-Porz
Institutes and Institutions:Institute of Aerospace Medicine > Radiation Biology
Deposited By: Kopp, Kerstin
Deposited On:09 Jun 2016 15:04
Last Modified:31 Jul 2019 20:01

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