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Bacteria in outer space exchange genes more often

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23.02.2007

Studying of bacteria cosmic transformation is very important for space flight safety. It is necessary to know the methods to maintain cosmonauts’ immunity, what drugs should be offered to them, and what new biostable materials should be developed for spaceship compartments and equipment.

Researchers have investigated the peculiarities of microorganisms’ physiology and behavior in space on the “Mir” orbiting space station, and found that bacteria change significantly in extraterrestrial conditions. In 2005, experiments on board the “Photon 2” space vehicle launched batches of bacteria into space. Among them there were several cultures of bacilli, streptomycetes and Escherichia coli, selected not at random, but because they differ from each other in terms of their physiology, biochemistry and genetics, thus providing a more comprehensive view on bacteria behavior in general.

In orbit, living organisms face not only the lack of gravitation, but also cosmic radiation presence. Bacteria in space become more aggressive, and can “eat” spaceship components. This happens because microorganisms start producing enzymes unusual for them in terrestrial conditions, which destroy structural materials. It is not improbable that bacteria become aggressive not only towards materials but also provoking unexpected diseases in humans. Cosmonauts already experience immunodeficiency problems in flight, which makes them more vulnerable.

Observations on board the “Mir” and “Photon 2” proved that microorganisms change even during short-term flights of 12-14 days. For example, streptomycetes changed their appearance (size, shape and outline of the colonies’ surface). The in-depth analysis also revealed genetic modifications of microorganisms. The number of their mutations does not increase, but some genes are disrupted. Some genes that are “dormant” on the Earth, begin to work, which generate the enzymes which damage structural materials.

Fortunately, when bacteria return to the Earth, they lose their aggressiveness, with changes that took place in orbit are reversible. Otherwise, similar problems could be expected on the Earth: destruction of materials and diseases in humans.

Nadezda Markina | Source: alphagalileo
Further information: www.informnauka.ru

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