. Astronauts on the International Space Station (ISS), share their environment with billions of germs – fungus, bacteria and other microbes that comprise the station’s microbiome. In the journal Microbiome, scientists found that the ISS contains more germs than cleanrooms in Earth’s Jet Propulsion Laboratory (JPL). Microbiome refers to the total number of microorganisms found in an environment. JPL researchers also found some microorganisms that may be harmful to human health in space station. After DNA analysis they stated that they couldn’t definitively prove whether the bacteria were harmful for astronaut health. The ISS microorganisms have been monitored by NASA in America, Roscosmos in Russia, JAXA Japan, and ESA Canada. This has been going on for 15years. To determine which strains of bacteria or fungus could be found, scientists from NASA and Roscosmos grew samples both in Earth’s lab and in space. The space station had higher levels of Actinobacteria than JPL’s clean rooms. It is difficult to get a complete picture of the microbiome composition at ISS. Some microbes can be difficult to grow in the laboratory and may have been overlooked in prior studies. NASA’s long-term mission to Mars will require the microbiome to be analyzed. It wants to know what type of microbiome humans may be bringing along on long-term manned space missions. The latest research used molecular analysis and state-of the-art molecular technology to examine ISS’ microbial ecosystem. The results were compared to bacteria that was found in clean environments at JPL on Earth. The scientists examined samples taken from an oxygen filter and a vacuum bag from the space station. They found opportunistic bacteria pathogens. Although they are generally harmless, these can cause skin inflammations or irritations. Corynebacterium (Actinobacteria) and Propionibacterium (“Actinobacteria”), a skin-associated bacterium were found to be much more prevalent on ISS than they are in Earth-based cleanrooms. However, Staphylococcus was not detected. Long-term space missions require scientists to understand the microbiome. Image: space.com. It is important to evaluate potential human and equipment damage. Kasthuri Venkateswaran (first author Aleksandra Chercinska) and Parag Vaishampayan were the study leader. They wrote that “Studying and understanding the microbiome on the station allows us to identify bacteria that can potentially cause damage to equipment, or harm astronauts’ health.” This study also helps to identify potential areas in need of more thorough cleaning.” JPL claims that the findings from this study will establish a baseline for hygiene monitoring in space station. In turn, it will protect astronaut’s health. It is unlike anything else on Earth. The station’s unique features include microgravity and higher levels of CO2 as well as space radiation. There is always six humans aboard ISS. Venkateswaran spoke out about the new DNA sequencing technology used for this study. He said that deep sequencing allowed them to look deeper at the microbiological population. The scientists stained the cells using a dye in order to see if they were still alive. They were able to determine the relative cleanliness of the Earth’s clean rooms and the differences in their fungal and bacteria populations. The higher Actinobacteria counts in space stations may have been due to the more rigorous cleaning protocols in Earth clean rooms. JPL stated on their website that the research didn’t address “virulence of the pathogens within closed environments” or the possibility of infection in astronauts. Venkateswaran, along with his colleagues, will use the latest DNA sequencing technology to examine how microgravity impacts these microbes. Microgravity can be detrimental to bacteria survival. However, a few microbes may survive it. The authors conclude that this information could be used to pinpoint sites which can benefit from more rigorous cleaning. The results can be used to compare the site with others and help improve the ISS’s health. Microbiome. Published 27 Oct, 2015. DOI: 10. 1186/s40168-015-0116-3.
