A new NASA study has looked at the bacteria present on the International Space Station (ISS), assessing the species that could potentially be harmful to both astronauts and equipment. The research provides useful insights that are important for long-term space flights, such as the agency's planned mission to Mars.
The environment on the ISS is very different to that you'll find back on Earth, with elevated carbon dioxide levels and microgravity, not to mention the fact that it's an enclosed space with a constant human presence. If we're to undertake missions involving long-term space flight, it's important to fully understand that environment, and a big part of that is getting to grips with the communities of microbes that exist within it, something that scientists call the microbiome.
NASA's new research, led by the Jet Propulsion Laboratory in California, focused on doing just that. It made use of cutting edge molecular analysis techniques, using DNA sequencing technology to quickly and accurately identify the immediate microbial community.
The researchers looked at samples from vacuum dust bags and air filters on the ISS. Collected microorganism samples were stained with a dye, allowing the researchers to determine whether the cells were alive or dead, and thus accurately assess the diversity and size of the bacterial population. Once the results were in, they were compared to readings taken in clean rooms back on Earth.
The results reveal that skin-associated bacteria Propionibacterium and Corynebacterium were more abundant on the station than in clean rooms back home. Such bacteria aren't usually harmful, but can lead to skin irritation or inflammation.
More broadly speaking, the research showed that Actinobacteria were more prevalent on the ISS than in the clean rooms – something that was attributed to the stringent cleaning regimens found in clean rooms, where there isn't a constant human presence like on the space station.
This first round of testing is only an initial step in understanding the microbial environment on the space station. In the future, the DNA sequencing technique could be used to study the effects of microgravity on the bacteria – something that's currently thought to have a negative impact its survivability.
If some bacteria are better at dealing with microgravity, they'll likely become more virulent in such an environment. Ensuring that we have a complete understanding of this will be important for long-haul space travel, such as NASA's mission to Mars, where making sure that both astronauts and equipment stays in optimum condition is a primary concern.
The results of the study were published in the journal Microbiome.