Scientists have found that certain types of bacteria seem to be a little too well-suited for space travel. This can pose some danger to astronauts, whose immune systems take a hit in space.
The discovery reveals a situation that can become problematic in the future. One big concern in space flight is the bacteria that astronauts will bring along with them to space. For bacteria like E. coli and salmonella, what doesn't kill them only makes them stronger.
Exposure to microgravity can cause apparently permanent genetic mutations in these bacteria. These genetic mutations have allowed the bacteria to be able to thrive in space, and have made the bacteria more reproductively fit. Even when the bacteria have returned to normal conditions, these mutations persist.
According to a recent study, E. coli bacteria managed to undergo at least 16 different mutations while in microgravity. A team of researchers at the University of Houston tested the effects of long-term space travel on bacteria. The researchers placed E. coli bacteria in a machine that simulates the conditions of microgravity out in space. The researchers also allowed the bacteria in the study to reproduce for 1000 generations.
As expected, the bacteria in the study adapted to the conditions they were in. The researchers then combined the mutated E. coli with a control strain of E. coli in normal conditions. The mutated E. coli grew three times as many colonies as the control strain.
There was also a scenario in which researchers took the bacteria out of microgravity for 30 generations before combining them with the control strain. The mutated bacteria retained over 70% of their reproductive success even after leaving microgravity conditions. This indicates that the mutations were not just temporary adjustments to new conditions. It's likely that the mutations were permanent.
Bacteria aboard the International Space Station (ISS) have shown that they thrive in space travel. These bacteria have formed biofilms—slimy layers of bacteria—on the interior surfaces of the ISS. Experiments have revealed that the cells of these space bacteria are thicker and had more biomass than those of Earth-bound bacteria.
While the fact that bacteria can thrive in space is quite interesting, it can also be quite problematic. For one thing, mutated bacteria can negatively impact astronauts. Microgravity and the conditions of space travel can suppress the immune systems of astronauts. Combine that with extra-strength bacteria, and astronauts will be in higher danger of contracting infections. There's also a chance that mutated bacteria will be resistant to antibiotics. However, the bacteria in the experiment were vulnerable to antibiotics, so there's hope that astronauts will be able to deal with possible infections in space.
Another problem is that astronauts may inadvertently bring mutated bacteria back to Earth and set them loose. These bacteria can then introduce traits that won't come about in normal conditions. Space travel can change bacteria in many ways, and we won't know for sure what mutated bacteria will be able to do on Earth. Thankfully, there's a big chance that our antibiotics will be able to deal even with super space bacteria.
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