What happens when cheerleaders and citizen scientists send bacteria into space? They discover a bacterial strain that seriously thrives, growing 60 percent better in zero gravity than it does on Earth, underlining a greater need to understand how microbes could behave on long-term space missions.
The findings, published in the March issue of the open-access biomedical journal PeerJ, are the culmination of the citizen-science undertaking Project MERCCURI, which asked members of the public to collect bacteria for a 2015 experiment aboard the International Space Station. Researchers at the University of California Davis teamed with several organizations, including Science Cheerleader, to recruit volunteers to collect bacteria swabs for testing and — with NASA approval — to send into space.
Science Cheerleader, whose members are former NFL and NBA cheerleaders currently pursuing science and technology careers, and the recruited volunteers submitted bacteria gathered from a variety of sources: high school football stadium seats, the Oakland Raiders practice football field, a Porta-Potty handle, the Liberty Bell, cell phones, the San Antonio Spurs basketball court, a dictionary at a magazine publisher's office, the Mercury Orbiter at the Smithsonian and the bottoms of sports' fans shoes, among others. Other scientists also collected samples, including the spore-forming microbe Bacillus safensis found on the Mars Exploration Rover at NASA's Jet Propulsion Laboratory before its 2004 launch.
Forty-eight of these microbes — including those taken from the Mars Exploration Rover — were approved by NASA for an experiment aboard the SpaceX Falcon 9, which traveled to the International Space Station in early 2015.
"We observed that the vast majority of the microbes we examined behaved the same on the Space Station as they do on Earth," says David Coil, a UC Davis scientist and the study's lead author. "In the few cases where we observed a microbe behaving differently in space than on Earth, we'd love to follow that up with further experiments."
Scientists aren't sure why, but one of the bacteria — Bacillus safensis taken from the Mars Exploration Rover — flourished in space. It grew 60 percent better aboard the ISS than it did on Earth. The ISS is technically a microgravity environment and not a true zero-G environment, as the station remains under Earth's gravitational influence. This isn't the first "space bacteria" found to thrive better in microgravity, but science has fully sequenced the Bacillus safensis genome, and now researchers are going to dive into the reasons why this one type of bacteria would grow so much faster if freed from Earth's gravity.
"Understanding how microbes behave in microgravity is critically important for planning long-term manned spaceflight," says Coil, "but also has the possibility of providing new insights into how these microbes behave in human constructed environments on Earth."
While the bacteria's behavior is intriguing, so too was the fact that so many laypeople were involved in collecting samples and participating in a mock "play off" between bacterial teams in space. As UC Davis scientists continue to analyze the results, they're also taking a closer look at microbes that didn't catch a ride into space, including more than 3,000 cell phone and shoe-sole samples from the public, to see how these bacteria compare to those collected by astronauts aboard the ISS.