Extremeophiles

Life can exist almost anywhere on Earth. It has flowed into every last nook and cranny, from the bottom of the sea to the upper edge of the stratosphere. From blazing heat and freezing cold to pure acidity and atomic bomb-caliber radiation, there’s seemingly no stress so great that some bug can’t handle it.

The pictures below are from a gallery that highlights some particularly tough species of bacteria and archaea. Less than 1 percent of Earth’s microorganisms have been identified, and most of those won’t even grow in a lab.

Hardly a month passes without some newly characterized species setting a new microbial benchmark. Indeed, the very concept of species might not apply. Bacteria and archaea exchange genes “horizontally,” without the need for reproduction. It’s as if, while encountering someone on the street, you could trade for whatever genes came in handy at the time. For example, if you put a particular plasmid into the common gut bacteria Escherichia coli, all of a sudden you have Klebsiella and not E. coli. You’ve changed not only the species, but the genus. It’s like changing a person to a chimpanzee.

With that in mind, below are the examples from the extremophiles gallery:

Herminiimonas glaciei, recovered from ice found two miles beneath a Greenland glacier is one of the smallest microbes ever found. With extra-long, tail-like flagella, it’s perfectly suited to moving through tiny veins in the ice:



Pyrodictium abyssi, discovered in 1979 on the nutrient-rich edges of deep-sea volcanic vents, are the original extremophile all-star. In addition to atmospheric pressure that could pancake a submarine, they can withstand temperatures well above the boiling point of water.

Like other archaea, the flat, irregular disk-shaped P. abyssi has no cell nucleus or organelles, making it a likely representative of life on an early, volcanic Earth. It accumulates in networks of hollow, tube-shaped structures called cannulae that are structurally resistant to heat:



Deinococcus peraridilitoris is the lesser-known cousin of Deinococcus radiodurans, dubbed the toughest bacterium on Earth by the Guinness Book of World Records. Found in 2003 in soil from the Atacama desert, a region of Chile so dry and desolate that NASA uses it for Mars simulations, it can withstand cold, vacuum, drought and radiation. Key to its survival are multiple copies of its genome; when one is damaged, the necessary sections can be copied from the other:



Haloquadratum walsbyi was found in a salt flat near the Red Sea, an environment so saline that just about every other organism on Earth would shrivel up into a "lifeless bag of desiccated stuff.” In response, the square and ultra-flat archaeon has the highest surface-to-volume ratio of any creature on Earth. You can’t get much more shriveled than that:



Halobacterium NRC-1 is the most radiation-resistant organism on Earth, capable of withstanding some 18,000 grays of radiation. (Just 10 grays are required to kill a human.) That nearly doubles the mark set by D. radiodurans, which was originally discovered in the 1950’s as the sole survivor of irradiated meat. Like D. radiodurans and D. peraridilitoris, it’s especially good at repairing its own DNA:



Ferroplasma acidophilum can grow in a pH of zero — conditions that make sulfuric acid look like mineral water. Found in the toxic outflow of a California gold mine, it uses iron as the central structural element of nearly all its proteins:



Desulforudis audaxviator is perhaps the one truly singular microbe. Every other known organism exists in a system in which at least some nutrients are provided by other creatures. But not D. audaxviator, which was discovered in a South African mine shaft, two miles beneath Earth’s surface and entirely alone. Using radioactivity from uranium-containing rocks as energy, it can harvest or metabolize every nutrient it needs from surrounding rock and gas — the world’s only known single-species ecosystem.



Original article here.