Teenage mutant space bacteria
FORGET Face-Huggers, Zenomorphs and Triffids, the real threat from outer-space might just be earthborn bacteria that has hitched a ride to our space stations.
According to recent, and very interesting, research conducted by the University of Houston, Texas, E. coli bacteria that travels into low or zero gravity environments becomes heavily mutated over a short span of time.
In the longest study yet of bacteria in simulated micro-gravity, the researchers found that the adaptations which had developed over 1000 generations of the organisms (quite a short span of time when it comes to bacteria) remained even when the researchers tried to erase them.
While in the low gravity environment, genome sequencing revealed that the bacteria had developed 16 mutations, the most notable of which was its ability to form biofilm - colonies of cells that are embedded in protective slime that makes the bacteria hardier.
But researchers are unsure of the functions of some of the other mutations.
“We are, in fact, seeing true genomic changes – permanent changes,” says team member George Fox at the University of Houston.
“We can see which genes are mutating, but we don’t know what they’re doing exactly.”
After giving the cells time to adapt in microgravity, the team at Houston then combined them with another strain of E. coli that had not been subjected to such an environment.
They found that the microgravitymutated bacteria grew at three times the rate of the regular bacteria.
In other words, not only was the Space-E.coli harder to kill, it grew much faster as well.
“This study is broader in scope than previous ones on two counts,” says Jason Rosenzweig at Texas Southern University.
“It’s looking at a much longer trajectory and it’s also interrogating the entire genome rather than specific subsets of genes.”
Even after the bacteria was removed from microgravity for 30 generations before being combined with the regular strain, it still retained 72 per cent of their adaptive advantage, which indicated to the researchers that it wasn’t merely of short term adaptive boost, but permanent mutations in the genes.
While the E.coli strains the scientists were dealing with were relatively innocuous, the mutated strain could potentially cause a problem if it attached itself to a space station’s life support system.
“We need more of this kind of experiment, especially with human space flight gaining more traction in recent years,” said research leader Madhan Tirumalai.
Tirumalai’s chief concern is that if E.coli can mutate at an accelerated rate in microgravity, other more harmful bacteria such as salmonella might do the same.
And given that astronauts’ immune systems are weakened in space, the threat of particularly virulent bacteria is of significant concern.
The good news is that while the cells grew faster and were less affected by their environment, the E.coli was still just as susceptible to antibiotics.
Researchers at the University of Houston, Texas have discovered that E. coli bacteria exposed to a microgravity environment (such as inside a space station) mutate rapidly and grow at three times the rate of the same strain on Earth.