Life at the Edge

Yes, life at the edge CAN be risky….But not for extremophiles!

Not only are extremophiles perfectly suited for their environments, they help us a lot more thanyou might think.

Scientists can learn a lot from studying extremophilesand how they have adapted.

Life first appeared on Earth about 4 billion years ago. Back then, Earth was hotter, had very little oxygen,toxic oceans and hardly any protection from UV rays. The whole Earth was like an extreme environment.

Could we have survived there? No, but some organisms were able to.

As Earth became more like we know it to be now,the extreme environments shrank. Scientists believethat some of earth’s first living organisms are verysimilar to the extremophiles we find today. They had to scatter and there are fewer of them as ourenvironment has changed.

Now, let’s take a look at some specific types ofextremophiles.

We will start with thermophiles, which are “heat-loving”organisms (usually bacteria).

They live in thermal pools at temperatures up to 176 degrees Fahrenheit (80 degrees Celsius).

How can thermophiles survive at such temperatures? And why can’t we?

Well, some thermophiles have a special set of proteins called HSP’s (heat shock proteins) that protect themfrom heat damage. We have them, too, but only produce them when we are overheated. Thermophiles make themall of the time.

Other thermophiles have a special enzyme called a“thermo-zyne” which works best at high temperatures.

(Enzymes are special proteins that speed up chemicalreactions that help to carry out body functions.)

One of these thermo-zynes is called Taq polymerase.

Taq polymerase can be used by scientists to takea small sample of DNA and turn it into a sample large enough to identify.

This can be used in crime labs to match DNA sampleswith suspects…even if only a tiny speck of DNA was left behind.

While we are on the topic of temperature, let’sdiscuss psychrophiles (organisms that love the cold).

Not only do they love the cold, they can’t livewithout it. They’d die at room temperature.

Organisms that live in the Arctic or Antarctic regionsmust survive very cold temperatures.

The winter flounder, shown below, lives in water that is28 degrees Fahrenheit (-2 degrees Celsius). That’s belowthe freezing point of their blood!

So just how do organisms manage to survive in such a cold environment?

Polar fish produce antifreeze proteins (AFPs) that lowerthe freezing point of its blood by a couple of degrees.

There are different types of AFPs, but all of themhave possible applications to various fields of scienceand technology.

For example, they could be inserted into plants to help them survive the winter. And they could be put into ice cream to prevent ice crystals from forming and keepingit creamier for a longer time. (Good idea!)