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 Space Shuttle Atlantis missions STS-132 on May 16, 2010 and STS-135 on July 8, 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.
Samples of bacteria Pseudomonas aeruginosa were cultured for three days in space, and formed a column-and-canopy structure not previously observed on Earth. Credit: NASA
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 shown to be associated with disease.
"Biofilms were rampant on the Mir space station and continue to be a challenge on the ISS, but we still don't really know what role gravity plays in their growth and development," said Collins, assistant professor in the Department of Chemical and Biological Engineering at Rensselaer. "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."
Results of the study were published by the journal PLOS ONE April 29, 2013 in the paper "Spaceflight promotes biofilm formation by Pseudomonas aeruginosa."
Beyond its importance for 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 said.