Extremophiles

These organisms thrive in environments that would normally be inhospitable to most living things by using molecules that help counter deadly environmental factors. These include antifreeze-like proteins that prevent psychrophiles from freezing and rupturing in polar regions, and osmoprotectants that prevent some extremophiles from losing water to salty environments.

Extremophiles possess unique enzymes and organic molecules that have enabled them to adapt to and thrive in otherwise lethal environments. Because these conditions resemble those found in various areas of manufacturing and production plants, these organisms and their macromolecules can optimize industrial processes where conventional catalysts would lose their ability to speed up reactions.

Acidophiles can survive in environments with acidity greater than that of the human stomach, and some radiophiles can live in places with radiation exposure hundreds of times higher than what is lethal to humans. Piezophiles—formerly known as barophiles—have been found in the Mariana Trench, where pressures are over 1,000 times larger than those on Earth's surface.

The conditions for life have long been thought to include liquid water, an energy source, and the essential elements for organic molecules within environments on or near Earth's surface. However, because extremophiles thrive in far more inhospitable environments, astronomers now analyze exoplanets whose characteristics indicate environments that fall within a broader range of possibilities when searching for signs of extraterrestrial life.

By expelling most of the water from their bodies, water bears assume a state resembling a dried-up cyst and can withstand extreme environments, such as arid deserts. But in this state and these environments, tardigrades cannot grow, reproduce, or perform other functions associated with life, unlike extremophiles like dry-loving xerophiles.

While investigating samples taken from within and around the hot springs at Yellowstone National Park, microbiologist Thomas Brock discovered Thermus aquaticus, a microorganism that thrived in hot water. It contained an enzyme called Taq polymerase, a critical molecule in polymerase chain reaction—a molecular photocopier that amplifies genetic signals to improve medical diagnostics.

When a can of ground beef and pork spoiled despite attempts to sterilize it with gamma radiation, researcher Arthur Anderson isolated the bacteria in the food and discovered Deinococcus radiodurans. The polyextremophile has since been found on the walls of nuclear reactors and overcomes radiation damage through highly optimized DNA repair mechanisms.

In the 19th century, coal processing plants, oil refineries, a tannery, and other industries lining the Gowanus Canal contaminated its waters with coal tar, sewage, and other pollutants, forming the toxic sludge. Samples taken from the site before clean-up efforts revealed over 450 species of microbes with metabolisms adapted to break down these various contaminants.

Developed following a five-week expedition to the southern continent, "Life Under the Ice" allows users to examine a petri-dish-like microscopic world and uncover recordings of organisms that can withstand, or even thrive, in the harsh environment.

Also known as "blood snow," the red coloration is produced by snow algae that thrive in extremely cold conditions and take the shape of red spherical cysts in winter. To protect themselves from more intense summer solar radiation, these psychrophiles accumulate red, orange, and yellow pigments, intensifying their coloration and causing glaciers to reflect less sunlight than if they were white.