Bacteria show symptoms of starvation in space
If you’re looking to starve a fever (or a cold?) but don’t want to stop stuffing yourself, consider heading to space. Assuming you’re dealing with a bacterial infection and not a viral one, living in microgravity may alter the physiology of bacteria enough to make it weaker than normal, even if your body was providing an otherwise amiable habitat. There may be a catch or two, but among other effects, microgravity seems to make bacteria struggle with starvation.
E. coli in orbit
To study this, scientists took a strain of Escherichia coli, the bacteria known for making us sick when it’s in our food, and split it into two groups. Half went to the International Space Station (ISS) on a Cygnus supply spacecraft, and the other half stayed on Earth for comparison. Both populations were first given access to food for 19 hours, then limited by exposure to antibiotics 30 hours later. At that point, a fixative agent was applied to basically hit the pause button on the bacteria’s activity until is could be analyzed.
Diminished by diffusion
The bacteria on Earth didn’t show any surprises, responding to food and antibiotics as you’d expect. The E. coli in space reacted a bit differently though. Genes associated with starvation were highly activated, as if the growth media given to the bacteria wasn’t there. On Earth, gravity assists the flow of nutrients through a bacterium, but in microgravity, that was only being accomplished through passive diffusion, and the bacteria couldn’t feed as efficiently. This also meant that the bacteria’s waste products weren’t being wicked away as quickly, building up an acidic environment and triggering genes associated with acid-resistance.
This doesn’t mean that beating bacterial infections in space is going to be a breeze though. Other experiments have found that microgravity also seemed to trigger bacterial growth, less susceptibility to antibiotics and stronger biofilms. Biofilms are like an outer wall that bacterial colonies build around themselves to repel would-be invaders, from medicines to our immune system’s white blood cells. So while bacteria may end up being a bit hungry in space, they may make up for it in a variety of other ways.
My three-year-old said: My bacteria is starving! I don’t like it!
Aside from the fact that he seemed to have missed the microgravity portion of this story, his concern does raise an interesting point. Our bodies are home to multitudes of benign and beneficial bacteria, and before humanity can safely spend years at a time in space, we’ll need to make sure the bacteria we want to keep are fed well enough to take the trip with us.
Source: Bacteria Show Signs of Starvation in Space by Mallory Locklear, The Scientist
