Living organisms survive because they are able to adapt to their environment. Scientists from the University of Colorado at Boulder have proven that bacteria is no different than other lifeforms. The scientists sent E. coli samples to the International Space Station, where astronauts monitored the samples. The results weren’t entirely surprising but they did provide researchers with a better idea of how bacteria reacts to antibiotics in space.
Researchers already knew that bacteria in space were more resistant to antibiotics than the same kinds of Earth-bound bacteria. They just weren’t certain why. The experiments on board the ISS revealed that E. coli bacteria develope a thicker membranous envelope in space, possibly making it more difficult for antibiotics to penetrate. Additionally, the cells are not as large as those on Earth but they are far more numerous. The number of cells increased 13 times while the size of the cells decreased by 75 percent.
A proliferation of smaller, more dense cells likely enabled the bacteria to protect itself from further antibiotic attacks. This form of protection has been likened to the same kind of response seen in pond scum and other bacteria. The cells clump, with the outer cells being sacrificed to protect inner cells.
The implications of these protective behaviors suggest that antibiotics will not be as effective as they are on Earth-bound bacteria and that E. coli’s ability to form biofilms in space is hazardous. Human astronauts enter space with their own human microbiomes that include many different kinds of bacteria and other microorganisms. These bacteria don’t pose a threat to healthy individuals. However the stresses of space can cause even healthy humans to have a suppressed immune system, making them more susceptible to opportunistic bacteria.
Biofilms grow on all kinds of surfaces and in the ISS there are many surfaces that could potentially contain growing clumps of bacteria. The scientists conclude that without further research and innovative protective measures, bacteria could make long-term space travel hazardous.