Since many years, human mankind travels to space. One of our
mayor interests is the health of astronauts and the protection of the
spacecraft. Apart from external influences, the microbial burden
inside of the International Space Station (ISS) may be dangerous
and must be limited to a minimum. To ensure the status and the
protection of the crew as well as the spacecraft itself, it is
necessary to determine the survival of microorganisms on
different surfaces. Microorganisms are constantly changing their
strategy of survival, primarily induced by extreme environmental
conditions, such as space conditions, compared to their terrestrial
habitats. However, the increased levels in resistance and
robustness possibly play a sensitive role in evolving new virulence
factors in the space environment.
One of the bacteria on the NASA Mars Odyssey spacecraft, which
have been isolated, is the Gram-negative, non-motile bacterium
Acinetobacter radioresistens. Apart from Deinococcus
radiodurans, A. radioresistens shows similar levels in radiation
and oxidative stress tolerance (McCoy et al., 2012). In our work, we used the strain 50v1, isolated from the surface of the Mars
Odyssey spacecraft as well as the type strain DSM6976, which
was isolated on Earth from cotton and soil samples. We
investigated the resistance regarding in their desiccation tolerance
on metallic surfaces including materials with different
antimicrobial properties. For those experiments we exposed and
desiccated both strains on the different surfaces (such as copperand
silver-containing materials) and determined the survival over
different time points. First results show a high resistance of the
spacecraft isolated strain compared to the type strain. These
results give implications about the higher survivability of
environmental microorganisms and highlight the essence of
bioburden reduction and improve sterilization
approaches/techniques for upcoming space exploration missions
towards the search for life outside Earth
