and Solar UV Radiation in the Space Environment (Expose-R Subtil) Expose – R Mutational Spectra of Bacillus subtilis Spores and Plasmid DNA Exposed to High Vacuum
TO HIGH VACUUM AND SOLAR UV RADIATION IN THE SPACE ENVIRONMENT (EXPOSE-R SUBTIL)
Research Area: Astrobiology
Expedition(s): 18- 26
Principal Investigator(s): ● Nobuo Munakata, University of Tokyo, Tokyo, Japan
RESEARCH OBJECTIVES
The Expose-R facility hosts a suite of
astrobiology experiments, some of
which could help understand how life
originated on Earth. This suite of
experiments are accommodated in 3
special sample trays, which are loaded
with a variety of biological samples and
exposed to the harsh environment of
open space for almost 2 years from
March 2009-January 2011. This
experiment determines the
mutagenicity of the spores of the
bacterium Bacillus subtilis induced by exposure to space vacuum and/or solar UV radiation. The
experiment will use 2 different strains of the bacteria, 1 of which is deficient in repairing UV-
induced photoproducts. The frequencies of rifampicin-resistant mutations and sequence
changes in the induced mutants (mutagenic spectra) will be determined and compared with
those obtained by the vacuum and solar-UV exposure
on the ground.
RESULTS
Results from Expose-R-Subtil are pending completion
of analysis and data evaluation before conclusive
results are prepared and published.
This investigation is complete; however additional
results are pending publication.
Sample containers are opened after they are returned to
Earth for analysis. ESA image.Colonies of Bacillus subtilis grown on a
culture dish in a molecular biology
laboratory. (Wikimedia Commons)