No abstract

No abstract

Investigations of the effects of solar radiation combined with the spaceflight factors on biological objects were performed in the «EXPOSE-R» experiment on the outer surface of ISS. After more than 1 year of outer space exposure, the spores of microorganisms and fungi, as well as two species of plant seeds were analysed for viability and the set of biological properties. The experiment provided evidence that not only bacterial and fungal spores but also dormant forms of plants had the capability to survive a long-term exposure to outer space.

Next phase of experiment TEST is aimed to evaluate microbial viability after a prolonged external exposure on the International space station (ISS). Methanogenic archaea isolated from various habitats have been tested in ground facilities for the ability to survive exposure to such open space factors as UV and vacuum. Methanosarcina mazei S-6T (VKM B-1636T) was found to be the most viable and, therefore, suitable for the experiment. Our investigations showed that the Methanosarcina mazei population maintained viability in the course of 24-month exposure. On this evidence we conclude that genome of this metanogenic archaea possesses mechanisms against the space vacuum, UV and thermal differences that, probably, underlie the ability of the strain to form peculiar cyst-like dormant cells.

No abstract