Spring and summer are seasons that teem with life. As they should: most life thrives in warmer temperatures. But a team of biologists led by Professor Ricardo Cavicchioli at the University of New South Wales in Australia is interested in life that hates the warm weather.
In the depths of Organic Lake, a small, salty body of water in Antarctica, these scientists found bacteria, fungi, and viruses known as psychrophiles thriving in temperatures as low as -20C. The water’s high salinity keeps it from freezing, this environment is the kind that could easily kill a warm-blooded mammal — much like humans — in a matter of minutes.
Organic Lake isn’t alone in these unique critters: In addition to those found in organic lake, scientists from McGill University in Canada have found bacteria living in the permafrost of the northern most region of the country. In February, even more creatures were found living in the sub-glacial Lake Whillans.
Bacteria found in Lake Whillans (credit New York Times)
Most life can’t survive in temperatures this cold because of the effect of temperatures on proteins and their membranes. Proteins are large molecules made of mostly organic material (think mostly carbon, nitrogen, hydrogen and oxygen with a few other elements in the mix for fun) that control pretty much everything we do, from digesting other forms of energy to movement. Whereas extreme heat may denature proteins by changing their shapes, extreme cold may make them sluggish, and they may not provide sufficient energy for even the most basic functions. Additionally, where most cell membranes become brittle and break in cold temperatures, psychrophiles up the levels of polyunsaturated fatty acids to make their membranes more pliable, so much so that they may degenerate in the inferno that is room temperature.
There are a number of different types of known bacteria, fungi and viruses we've studied already. We typically don’t care about them, unless they are making us sick or helping our bread rise. However, the fact that even more have been found in this Hoth-like setting is remarkable, and has important implications for a variety of fields.
Fungi found in Antarctica (credit: Smithsonian mag)
Psychrophiles give us clues about different types of genetic diversity. Among these bacteria, fungi and even viruses that infect other viruses are different sequences of DNA that we don’t see in lukewarm loving creatures. As Cavicchioli and others continue to examine the genetic makeup of these forms of life, they could begin unlocking the clue to different types of diversity that could shine light on evolution and other forms of life that may exist out of this world.
A virus found in Organic Lake. (Credit: PBS)
The differences in these forms of life could tell us what kind of things to expect on other planets. Astronomers believe that if we can find life on other planets, it would be critters like these. The dry ice caps on Mars’ poles hint that there could be water on our next-door neighbor that could also support life. And satellites show that Jupiter’s moon Europa may have an ocean under a thick layer of ice. These may have all be considered uninhabitable before, but new-found friends in Antarctica may mean that there’s similar life out there.
Far less alien is the idea of harnessing cold-functioning proteins for use at room temperature for even more efficient practices. There’s already a Belgian company that produces cold-functioning yeast for fast-rising bread; imagine what other types of cold-functioning bacteria could improve our quality of life.
Historically, scientists have avoided studying these types of organisms because it was impossible to study them in a laboratory setting without killing them. Even at temperatures we may find cold, these psychrophiles simply can’t take the heat.
As scientists begin to scrape the surface of psychrophiles, let’s hope that things like climate change don’t hinder further progress in this fascinating field.