Most
modern organisms require specific conditions to survive: liquid water, oxygen,
moderate temperatures, stable aboveground air pressure, and low-level radiation
exposure. However, not all terrestrial organisms live harmoniously under such
moderate conditions; in fact, there are extremophiles living in generally
life-threatening environments, and several “ordinary” microbes are capable of
readily adapting to extreme conditions.
According
to a meta-analysis by the International Space Station’s (ISS’s) microbial
research teams, humans bring large microbiomes on board even after going
through pathogen-removal quarantine for 10 days before entering the spacecraft.
Lingering microbes sparked several ideas in astrobiologists wanting to see how
microorganisms change in the ISS and space shuttle’s closed-system microgravity
environments.
Between
2006 and 2008, researchers sent several Salmonella
typhimurium samples into low-Earth orbit on the space shuttles Atlantis and
Endeavour. Once returned to Earth, the S.
typhimurium was injected into mice and found to be more virulent than usual.
These
findings left scientists wondering if the ability of microbes to adapt to new
environments poses greater contamination threats than originally thought.
For
further details see:
Posted by Dr. Tim Sandle