We know that bacteria are pretty much everywhere here on Earth, but what about onboard the International Space Station (ISS)?
Attempting to establish a baseline for monitoring the cleanliness of the orbiting laboratory, as well as determine how the microbe populations on the facility differ from those found on Earth, Dr. Kasthuri Venkateswaran of NASA’s Jet Propulsion Laboratory (JPL) and his colleagues took samples from the ISS as well as from two cleanrooms at their Pasadena-based campus.
As the authors explained in the latest edition of the journal Microbiome, they analyzed each of those samples using traditional microbiology techniques. These techniques culture bacteria and fungi in the lab, along with advanced DNA sequencing methods to quickly and precisely identify the types of microorganisms present on the space station and compare them to those found on Earth.
They found that a type of bacteria associated with human skin, Actinobacteria, made up a larger proportion of the microbial community on the ISS than in the cleanrooms, which the researchers believe could be due to stricter cleaning procedures used in the ground-based facilities.
Findings could improve cleaning practices, ensure astronaut health
Furthermore, they discovered that two different groups of potential infection-causing pathogens were present in air filter samples and vacuum bag dust from the ISS. These bacteria could result in skin irritation or inflammation, but since the basis of the study was genetic analysis, the study authors said that they could not determine if they posed a threat to astronaut health.
One of the key differences between the ISS and the Earth-based cleanrooms, Dr. Venkateswaran said, are that the cleanrooms constantly circulate fresh air while the air on the space station had to be filtered and recirculated. In addition, the ISS is continuously inhabited by six people, while the cleanrooms are used off-and-on by up to 50 scientists every day.
In a statement, Dr. Venkateswaran explained, “By using both traditional and state-of-the-art molecular analysis techniques we can build a clearer picture of the International Space Station’s microbial community, helping to spot bacterial agents that may damage equipment or threaten astronaut health, and identify areas in need of more stringent cleaning.”
“The results obtained will facilitate future studies to determine how stable the ISS environment is over time,” he and his fellow authors wrote. “This information can be used to identify sites that can be targeted for more stringent cleaning. Finally, the results will allow comparisons with other built sites and facilitate future improvements on the ISS that will ensure astronaut health.”
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Feature Image: NASA
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