Microbial Life in Space: Response to Environmental Factors in a Space Vehicle (Microspace) - 01.09.14
Science Objectives for Everyone Information Pending
Science Results for Everyone Information Pending
Tuscia University, Viterbo, , Italy
Sponsoring Space Agency
European Space Agency (ESA)
ISS Expedition Duration:
October 2004 - October 2005
Previous ISS Missions
The aim of the research is to study the response of representative non pathogenic microorganisms to the environment inside the space vehicle and at different mission stages. Microorganisms are well known for their capabilities to withstand extreme environmental conditions such as elevated temperature, high salinity, hydrostatic pressure, and toxic compounds. The exposure to radiations, vacuum, electricity, and magnetic waves has been investigated in the past, but still little information is available about the effects of the space environment on microorganisms. Different microbial strains will be flown to the ISS in order to study the effect that space radiation and the weightless environmental conditions onboard the ISS have on the cultures. The microbial strains selected for the experiment are non hazardous, of environmental origin, and some of them (Saccharomyces cerevisiae, Escherichia coli, Enterococcus faecium, Lactobacillus acidophilus) are commonly hosted by humans. This experiment may improve our understanding on the basic biology of microorganisms, particularly on their tolerance to the spacecraft environment and on how the genetic material in the cells can be affected by in-flight space conditions. The experiment can further provide a greater understanding of the spacecraft environment itself.
Microorganisms will be tested as lyophilised (free-dried) cultures and/or spores in order to evaluate cell number, viability and cell integrity. The selected strains will be treated as live but non-active cells in order to optimise expenses, experimental work, and to make both storage and transportation easier. Moreover no crew is involved in executing the experiment. In the ground lab the selected cultures will be cultivated under optimal conditions and stored until the experiment begins. At this stage (T0) lyophilised cultures and/or spores will be prepared, appropriately packed, and shipped; part of these cultures will be collected and analysed (cell number, viability, cell integrity, and genetic pattern) as a T0 control. Microorganisms will be kept inside 2 ml cryo-vials and then placed inside 80 ml Sigma centrifuge tubes that will be assembled in the lab as sub-packages in Ziploc-like bags and easily transported to the launch site. A Smartbutton temperature data logger will be added to each pouch. A filter made of microbiological cotton will be inserted inside each Sigma Centrifuge tube. Three pouches containing identical samples will be assembled so that they are tested at different mission times. At the end of the present mission two pouches will be retrieved by Soyuz and one will remain on the ISS until the next mission. Once back at the ground lab, quantification of cells will be carried out by means of optical microscopy, whereas the morphological cell structure will be determined via electron microscopy. As the stress the cells are exposed to during the flight mission may induce modifications in the genome of microorganisms, a further topic of the present experiment is the analysis of total DNA by means of molecular techniques. A ground reference experiment will be kept in the Laboratory of Agricultural and Environmental Microbiology at the University of Tuscia and analysed following the same protocol, so that it will be possible to compare the response of microorganisms under both space and terrestrial conditions. The selected microbial cultures are chosen among genera Saccharomyces, Escherichia, Lactobacillus, Bacillus, Pseudomonas, Rhizobium, Enterococcus, Streptococcus and Thermococcus, so that the work may be performed with species of different environmental origins and capable of surviving during the mission and under the onboard average environmental conditions. Moreover, further experiments will be carried out using the same bacterial species in a simulator on Earth to investigate the effects of space radiations on bacteria.
Microspace experiment pouch. Image courtesy of ESA.
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