A team of researchers in the Canadian Arctic is reporting on an interesting find: bacteria that thrive at –15 degrees Celsius. That is the coldest environment bacteria have ever been found to grow in.
The McGill University researchers traveled to Ellesmere Island in (far, far) north Canada. There they collected and later cultured about 200 microbes, putting the organisms in a simulation of their native environment to find the one best-suited for living in extreme conditions. The winner ended up being a strain of Planococcus halocryophilus, which made its home in tiny veins of salty water in the Arctic permafrost. The researchers have reported that the bacteria can grow in those harsh conditions, and survive at temperatures down to –25 degrees Celsius.
The fact that the bacteria can survive at those temperatures is cool alone, but it also has implications for the search for bacteria (living or gone) on Mars and Saturn's moon Enceladus. Both Mars and Enceladus may have salty, super-cold places similar to the places where this bacteria made its home. (That, in general, is a big reason so many scientists are interested in digging for completely new, "alien" species in the Arctic.)
So what makes this bacterium so tough? The team examined its genome and cellular structure to find out, and determined it had an abnormal amount of cold-resistant proteins and especially well-adapted membranes.