A Microbe Census Deep in the Earth
October 14, 2011 Leave a comment
There are lots of microorganisms out there; we’ve only identified a fraction of them. Just as the deep dark oceans represent a huge question mark in terms of the incredible amount of undiscovered species, the subterranean offers a daunting opportunity to discover new forms of life. A new census, called the Census of Deep Life, is determined to find and categorize microorganisms living 10 to 100 kilometres below the Earth’s crust.
A microbe, or microorganism, is just an organism that you can only see under a microscope. They’re usually unicellular. Bacteria are the most prominent example, but there are others across the spectrum, like algae (various kingdoms), slime molds (protist), yeast (fungus), dust mites (animal), and even single-celled plants.
Little research has been done to identify the unicellular denizens of the Earth’s inhospitable depths. An ocean microbe census indicated that as many as a billion kinds of microorganisms live in the planet’s seas, but the deep Earth is more difficult to access, and microbial populations are more sparsely distributed.
Yet the data that are available on crust-dwelling species suggest that as many as several million categories of bacteria and their unicellular relations could live in the planet’s deeps…
For the census-takers of microbes, it’s a huge challenge to identify distinct species.
“Microbiologists have tried to do so the way traditional biologists have, but they’re frustrated by this because microorganisms tend to trade DNA,” Colwell said. In fact, microbes can swap DNA by merely engaging in what amounts to hand-holding.
Such a cavalier exchange of genetic material makes it difficult to unequivocally differentiate one group of microorganisms from another.
However, the microbe census is focused on getting samples from deep, isolated communities that have been left to their own evolutionary devices for long periods of time, and may have distinctive genetic characteristics.
The project receives rock and fluid samples retrieved from diverse environments such as caves, mines, and drill projects on land, and from projects in the ocean that have drilled deep beneath the seafloor.
Finding very unique species would be awesome. For example, a very important protein used in labs for DNA replication was taken from bacteria that were discovered in hot springs at 70°C. The protein is useful because of its resistance to heat, and is key to conducting modern molecular biology research. Who knows how discovering novel kinds of life could change science in the future?
On a separate note, I probably won’t be posting anything tomorrow (unless I really need a break) because I have my GRE biochemistry test on Saturday morning, and I have a marathon of cramming to do before then. Afterwards I’ll make up for it with some extra posts though, for your and my entertainment – provided this test doesn’t turn me off of science entirely.