St Petersburg University scientists to be world’s first researchers to study bacteria-resistant behaviour in space
Researchers at St Petersburg University are already studying biofilms, which are communities of microorganisms, under the conditions of microgravity. Their findings will help prevent bacterial biofilms from appearing on surfaces inside spaceships and provide prophylactic measures against disease among the crew of the International Space Station (ISS).
Bacterial biofilms are the principle means by which microorganisms are able to survive in natural habitats. They are part of the human microbiome and are found on the mucous membranes of the gastrointestinal tract, on the surfaces of internal organs and also in the skin. Biofilms can consist of one or more species of microorganisms, bacteria or microfungi, enveloped in a protective polysaccharidic surface film. This ensures that the bacteria in them are hundreds of times more resistant to negative factors in the surrounding environment, including germicides, than free-living microorganisms. The surface film acts as a molecular sieve that captures external agents, limiting the penetration of drugs into the depths of the biofilm.
Bacterial biofilms are responsible for a host of diseases in humans, including chronic infections. The researchers at St Petersburg University are now studying their formation during space flight, under conditions of microgravity. ‘Such research is necessary in order to prevent bacterial biofilms from appearing in the living area of a spaceship and to develop an effective strategy for counteracting the biofilms of pathogenic bacteria and preventing astronauts from falling ill during long-term space missions,’ commented Oksana Rybalchenko, Professor at St Petersburg University and the director of this project. According to her, the overarching goal of the project is to investigate the interaction between bacterial cells in mixed microbial communities and their impact on the body in microgravity.
The Biofilm Project, which includes research into the formation of biofilms in microgravity, is part of a long-term programme of applied scientific research and space experiments on the Russian segment of the International Space Station and is supported by the Roscosmos Corporation (the Russian Federal Space Agency).
For the first time in a space experiment, these scientists are studying bacterial biofilms of probiotic microorganisms – lactobacteria – and they are analysing the dynamics of biofilm formation on the surfaces of different carriers. They have found that the rates at which biofilms build up in weightlessness are higher than on Earth. The growth rate of bacteria in biofilms, however, depends on the surface properties of the carrier. The highest growth rates turn out to be on surfaces made of polystyrene, a material that is often used in the manufacture of instrument parts and laboratory dishes.
Since 2013, thirteen space experiments have been conducted as part of this project, and two more missions to investigate the development of bacterial biofilms in different species of probiotic bacteria under exposure to antimicrobial agents are planned for this year. In the long run, these scientists would like to study the stress of space flights on different groups of microorganisms – bacteria and yeast.
Their findings will help in the selection of new anti-microbial drugs and disinfectants, and also in finding methods for treating modular surfaces in manned-space complexes. This will make it possible to lower the health risks for the crew and ensure the proper functioning of equipment on the International Space Station.