Astronauts are not the only inhabitants of space stations. Side by side with human beings, millions of microorganisms populate an islet of civilization in space. "Microbes are the main inhabitants of a space station," says Natalia Novikova, a head of research group at the Institute for Biomedical Problems, who investigates microbe conglomerations at the MIR station and the International Space station. "The astronauts come and go, and the microbes stay." Microbes cause a lot of trouble to a station, so anti-microbe protection is needed. The scientists from the Institute for Biomedical Problems have proposed an original method of disinfection in space.
How do microorganisms get into space? Infinite number of these tiny beings inhabit human organisms, cover the surface of equipment and they are carried in by transport spaceship from the Earth. At a station, some of them fail to survive, but the majority adapts themselves to extraterrestrial conditions and occupies a suitable econiche in a new environment. These are mainly bacteria and fungus.
When the scientists compared the space microorganism cultures with similar ones on the Earth, they found out that the microbes had changed in space. Apparently, this happened due to ionizing radiation. Anyway, microbes underwent the same changes during terrestrial experiments when they were exposed to the same radiation dose for a lengthy period.
As has been mentioned earlier, a space station is very likely to face critical problems because of microbes. They inhibit construction surfaces, feed on them, and damage them with their life cycle products.
The acids some bacteria secrete cause metal corrosion and damage the instruments and illuminators. It is critical to fight with microbes at a space station, but standard methods do not work there. The disinfecting materials, which are usually effective on the Earth, are not applicable in a closed environment because they are toxic. Even if the disinfectants are quite harmless, nevertheless the microbe cells are excreting toxins when they die.
Developers of anti-microbe protection means have elaborated two efficient methods. The first way is rather traditional. Due to special treatment space materials acquire anti-microbe and antifungoid properties, for instance, they become hydrophobic. As a result water vapour does not precipitate on the material; and microbes can not survive on an absolutely dry surface.
The second way appears to be much more interesting. Researchers have developed a special technique to turn microorganisms into anabiosis, a state when all life cycle processes slow down, and cells do not grow, reproduce or secrete harmful substances. Scientists have investigated natural substances, which induce microorganisms to turn into anabiosis, and synthesized their analogues in the laboratory environment. These substances are benzene derivatives and are known as polymodal anabiosis autoinductors. The chemicals have been successfully tested in the terrestrial conditions: they stop the microorganism growth and metabolism. This method of protecting a space station involves only the effort of applying polymodal anabiosis autoinductors to construction materials and instruments.
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