Format

Send to

Choose Destination
Astrobiology. 2018 Nov;18(11):1425-1434. doi: 10.1089/ast.2017.1715. Epub 2018 Oct 5.

Comparing Spore Resistance of Bacillus Strains Isolated from Hydrothermal Vents and Spacecraft Assembly Facilities to Environmental Stressors and Decontamination Treatments.

Author information

1
1 Department of Chemical, Biological, Pharmaceutical and Environmental Sciences, Research Center for Extreme Environments and Extremophiles, University of Messina , Messina, Italy .
2
2 Space Microbiology Research Group, Radiation Biology Department, Institute of Aerospace Medicine , German Aerospace Center (DLR e.V.), Cologne, Germany .
3
3 Biomedical Applications of Plasma Technology, Institute for Electrical Engineering and Plasma Technology, Faculty of Electrical Engineering and Information Technology, Ruhr University Bochum , Bochum, Germany .
4
4 Leibniz-Institute DSMZ-German Collection of Microorganisms and Cell Cultures , Braunschweig, Germany .

Abstract

Submarine hydrothermal vents are inhabited by a variety of microorganisms capable of tolerating environmental extremes, making them ideal candidates to further expand our knowledge of the limitations for terrestrial life, including their ability to survive the exposure of spaceflight-relevant conditions. The spore resistance of two Bacillus spp. strains, APA and SBP3, isolated from two shallow vents off Panarea Island (Aeolian Islands, Italy), to artificial and environmental stressors (i.e., UVC radiation, X-rays, heat, space vacuum, hydrogen peroxide [H2O2], and low-pressure plasma), was compared with that of two close phylogenetic relatives (Bacillus horneckiae and Bacillus oceanisediminis). Additional comparisons were made with Bacillus sp. isolated from spacecraft assembly facilities (B. horneckiae, Bacillus pumilus SAFR-032, and Bacillus nealsonii) and the biodosimetry strain and space microbiology model organism Bacillus subtilis. Overall, a high degree of spore resistance to stressors was observed for the strains isolated from spacecraft assembly facilities, with an exceptional level of resistance seen by B. pumilus SAFR-032. The environmental isolate SBP3 showed a more robust spore resistance to UVC, X-rays, H2O2, dry heat, and space vacuum than the closely related B. horneckiae. Both strains (SBP3 and APA) were more thermotolerant than their relatives, B. horneckiae and B. oceanisediminis, respectively. SBP3 may have a novel use as a bacterial model organism for future interrogations into the potential of forward contamination in extraterrestrial environments (e.g., icy moons of Jupiter or Saturn), spacecraft sterilization and, broadly, microbial responses to spaceflight-relevant environmental stressors.

KEYWORDS:

Bacillus species; Chemicals; Heat; Planetary protection; Radiation; Spore resistance; Sterilization

PMID:
30289268
DOI:
10.1089/ast.2017.1715

Supplemental Content

Full text links

Icon for Atypon
Loading ...
Support Center