In a study published Tuesday in the journal PeerJ, a team of scientists presents an overview of groups of microorganisms that share a common living space, known as microbial communities, aboard the ISS.
The research demonstrates how the ISS is not too different from the average home, at least in terms of its microbial community.
“‘Is it gross’ and ‘Will you see microbes from space’ are probably the two most common questions we get about this work,” said co-author David Coil, a microbiologist at the University of California, Davis.
“As to the first, we are completely surrounded by mostly harmless microbes on Earth, and we see a broadly similar microbial community on the ISS. So it is probably no more or less gross than your living room.”
The team analyzed bacteria found on 15 locations on the ISS, as well as swabs from astronauts, and compared them to samples from the Human Microbiome Project and homes on Earth.
“Since the ISS is completely enclosed, the microbes inside the station come from the people on the ISS and the supplies sent to them,” Coil said.
Jenna Lang, a former postdoctoral scholar at UC Davis and lead author of the report, echoed Coil’s point.
“The microbiome on the surfaces on the ISS looks very much like the surfaces of its inhabitants, which is not surprising, given that they are the primary source,” she said. “We were also pleased to see is that the diversity was fairly high, indicating that it did not look like a ‘sick’ microbial community.”
The research is part of a nationwide citizen science initiative known as Project MERCURRI. The partnership is a collaboration between several organizations, including UC Davis and Science Cheerleader, a group of current and former professional sports cheerleaders working in the fields of math and science.
Project MERCURRI previously collected 48 bacteria samples from around the United States and sent them to the ISS. The group found that one of the bacteria actually grew better in space.
Study co-author Jonathan Eisen, a professor of medical microbiology and immunology, and of ecology and evolution, at UC Davis, says the findings from Project MERCURRI studies are important to understanding the differences between the microbial communities on Earth and the ISS.
“Studying the microbial diversity on the ISS is not only of relevance to space exploration but also serves as an important comparison to buildings on Earth because the ISS has many novel features, such as limited influx of microbes,” he said.