Bacteria Sent Into Space Behave in Mysterious Ways
Colonies of bacteria grown aboard space shuttle Atlantis behaved in ways never before observed on Earth, according to a new NASA-funded study from Rensselaer. Recent findings provide important evidence of spaceflight’s effect on the behavior of bacterial communities and represent a key step toward understanding and mitigating the risk these bacteria may pose to astronauts during long-term space missions.
The research team, led by Rensselaer faculty member Cynthia Collins, sent the experiment into orbit aboard Atlantis’ STS-132 mission in May 2010 and its STS-135 mission in July 2011. Samples of the bacteria Pseudomonas aeruginosa were cultured for three days in artificial urine. The space-grown communities of bacteria, called biofilms, formed a column-and-canopy structure not previously observed on Earth. Additionally, biofilms grown during spaceflight had a greater number of live cells, more biomass, and were thicker than control biofilms grown under normal gravity conditions.
Biofilms are complex, three-dimensional microbial communities commonly found in nature. Most biofilms, including those found in the human body, are harmless. Some biofilms, however, have been found to be associated with various diseases.
“Biofilms were rampant on the Mir space station and continue to be a challenge on the International Space Station, but we still don’t really know what role gravity plays in their growth and development.”
“Biofilms were rampant on the Mir space station and continue to be a challenge on the International Space Station, but we still don’t really know what role gravity plays in their growth and development,” said Collins, an assistant professor in the Department of Chemical and Biological Engineering. “Our study offers the first evidence that spaceflight affects community-level behaviors of bacteria and highlights the importance of understanding how both harmful and beneficial human-microbe interactions may be altered during spaceflight.”
Beyond its importance to astronauts and future space explorers, this research also could lead to novel methods for preventing and treating human disease on Earth. Examining the effects of spaceflight on biofilm formation can provide new insights into how different factors, such as gravity, fluid dynamics, and nutrient availability, affect biofilm formation on Earth. Additionally, the research findings could one day help inform new, innovative approaches for curbing the spread of infections in hospitals, Collins says.
“The opportunity to conduct microbiology research aboard spacecraft is valuable and unique,” said Macarena Parra, who served as the study’s payload science adviser at NASA’s Ames Research Center, Moffett Field, Calif. “Aboard free-flying satellites, or using laboratory facilities aboard the ISS, allows researchers to validate ground-based experiments and discover results that can only be observed in space.”
There is no substitute on Earth for true microgravity conditions. Although ground-based researchers use methods to simulate microgravity in their laboratories, each of these methods has limitations. The results from simulated-microgravity experiments do not always match those seen in actual spaceflight, Parra said.