Autoclaves—would you cook a turkey in this?
At Popular Science is a profile of food scientists given an impossible task: make year-old mashed potatoes taste good. Food that lasts a year on the shelf needs to be sterilized, and that is a battle against extremophiles. Our most effective weapon is a very blunt one—heat. 252 degrees Fahrenheit to be exact.
Writer Paul Adams tours a food science lab and gets a taste of “retort flavor” in his sterilized mashed potatoes. The unappetizing term refers to the retort, a machine that obliterates microbes and flavor in one fell (and very hot) swoop:
The potatoes look right, once we’ve fluffed them up a bit, but the wholesome earthy taste and smell of fresh potatoes is almost gone from the dish. In its place there’s a tired, wet-paper flavor with notes of old steam pipe. This side effect of confined high-heat cooking is known in the trade as “retort flavor.” Stuckey’s theory is that it’s just underlying parts of the flavor coming through. Before food is retorted, she says, the dank base notes present in it are masked in part “by the beautiful aromatic volatile notes that we take for granted. When the retort destroys these low-molecular-weight flavors, what’s left is the ugly insides.” Read More
An image of the Martian surface from NASA’s Viking 2
To eke out even the barest subsistence on Mars, a living thing would have to adapt to a formidable set of environmental challenges: an arid, often extremely cold landscape with miniscule amounts of oxygen in the atmosphere and no organic matter to eat. During a recent foray into a similarly inhospitable part of our own planet, scientists have discovered several species of bacteria that hint at what life on Mars, if it exists, might look like. These microbes survive on minerals in the surrounding rocks—minerals also found in the Martian surface.
A cluster of 3.4 billion-year-old fossilized cells
What’s the News: Geologists have found fossils of microorganisms from 3.4 billion years ago, which may be the oldest fossils ever uncovered. Since these microbes date from a time when Earth’s atmosphere was still oxygen-free, astrobiologists could look for similarly structured microbes when searching for extraterrestrial life.
What’s the News: Some bacteria can live in extreme “hypergravity,” found a new study published in the Proceedings of the National Academy of Sciences, surviving and reproducing in forces 400,000 times greater than what’s felt on Earth. These findings fit with the idea that microbes carried on meteorites or other debris—a ride that would have subjected them to hypergravity-strength forces—may be the ancestors of life on Earth.
At the bottom of the ice sheet at the bottom of the world lies one of the most pristine and tantalizing places on the Earth—a lake beneath Antarctica that has been isolated for millions of years. Soon, humans will get a glimpse of Lake Vostok.
Since 1990, the Arctic and Antarctic Research Institute [AARI] in St Petersberg in Russia has been drilling through the ice to reach the lake, but fears of contamination of the ecosystem in the lake have stopped the process multiple times, most notably in 1998 when the drills were turned off for almost eight years. Now, the team has satisfied the Antarctic Treaty Secretariat, which safeguards the continent’s environment, that it’s come up with a technique to sample the lake without contaminating it. [Wired]
At about 6,200 square miles, Vostok is nearly the size of Lake Ontario. Its temperature actually remains a few degrees below freezing, but the pressure on the water allows it to stay in liquid form. It’s the isolation, though, that has everyone so excited. There are more than 150 lakes beneath the Antarctic glaciers, but Vostok is the only one that’s entirely cut off.
NASA’s big astrobiology news last week had nothing to do with E.T., of course—the team behind a study in Science announced the find of a kind of bacteria that appear to thrive in arsenic and can even use it in place of phosphorus in the backbone of its DNA double helix. But after the big announcement finally happened and squelched the more imaginative rumors, scientists started asking some hard questions about the study online.
Over at Slate, DISCOVER blogger Carl Zimmer rounded up expert critiques from biologists, and many didn’t hold back.
Almost unanimously, they think the NASA scientists have failed to make their case. “It would be really cool if such a bug existed,” said San Diego State University’s Forest Rohwer, a microbiologist who looks for new species of bacteria and viruses in coral reefs. But, he added, “none of the arguments are very convincing on their own.” That was about as positive as the critics could get. “This paper should not have been published,” said Shelley Copley of the University of Colorado. [Slate]
The science world is abuzz with news of a strange new life form found in California’s Mono Lake: Researchers report that they’ve discovered a bacterium that can not only thrive in an arsenic-rich environment, it can actually use that arsenic to build its DNA. If the researchers, who published their findings in Science, are correct, then they’ve found a form of life unlike anything we’ve ever seen before.
As you might expect, DISCOVER’s blogs offered plenty of coverage of this exciting news.
At The Loom, Carl Zimmer writes: “Scientists have found a form of life that they claim bends the rules for life as we know it. But they didn’t need to go to another planet to find it. They just had to go to California.”
At Bad Astronomy, Phil Plait explains exactly how the bacteria can make use of arsenic to build their DNA. A few days ago, Phil also took NASA to task for its press release promising news of “an astrobiology finding that will impact the search for evidence of extraterrestrial life,” which fueled wild speculation on whether NASA had found little green men in the solar system.
At Not Exactly Rocket Science, Ed Yong debunks a few of the more breathless accounts. The bacteria do not “belong to a second branch of life on Earth…. They aren’t a parallel branch of life; they’re very much part of the same tree that the rest of us belong to. That doesn’t, however, make them any less extraordinary.”
80beats: Life Found in the Deepest, Unexplored Layer of the Earth’s Crust
80beats: Do Asphalt-Loving Microbes Point the Way to Life on Titan?
80beats: Arsenic-Eating Bacteria May Resemble Early Life on Primordial Earth
DISCOVER: Renewed Hope for Life on the Red Planet
At this point, after finding microorganisms that don’t mind extreme temperatures, pressure, aridity and other hardships, we shouldn’t be surprised that bacteria‘s dominion over the Earth extends to just about anywhere we look. A new expedition to the Earth’s crust has reached unprecedented depths—down to the deepest layer of the crust—and found that even there, microorganisms are tough enough to survive.
On a hypothetical journey to the centre of the Earth starting at the sea floor, you would travel through sediment, a layer of basalt, and then hit the gabbroic layer, which lies directly above the mantle. Drilling expeditions have reached this layer before, but as the basalt is difficult to pierce it happens rarely. [New Scientist]
To circumvent the Herculean task of drilling through basalt, the expedition, called the Integrated Ocean Drilling Programme, headed out to sea to find an easier drilling location.
The Integrated Ocean Drilling Program sank its drill into the Atlantis Massif (seen above) in the central Atlantic Ocean where seismic forces have pushed the deep layer, known as the gabbroic layer, to within 230 feet of the ocean floor making it easier to reach. [UPI]
Want to know what early or extraterrestrial life might look like? You might try looking at Earth’s extremes: the coldest, highest, and deepest places on our planet. One unmanned research vehicle just tried the last of these strategies, and took samples from a hydrothermal vent plume 16,000 feet under the sea–about 2,000 feet deeper than the previous record-holding vent.
A research team led by Woods Hole Oceanographic Institution (WHOI) and including scientists at NASA’s Jet Propulsion Laboratory studied three hydrothermal vents, found along an underwater ridge in the Caribbean called the Mid-Cayman Rise. They published their findings yesterday in The Proceedings of the National Academy of Sciences.
Hydrothermal vents are usually found in spots where the Earth’s tectonic are moving away from each other, creating a weird zone of raw chemistry. A mixture of hot vent fluids and cold deep-ocean water form plumes, which can contain dissolved chemicals, minerals, and microbes. Instead of searching the entire 60-mile-long ridge with the vehicle, the team scouted for chemicals from the plume to zero-in on the vents.
“Every time you get a hydrothermal system, it’s wet and hot, and you get water and rocks interacting. Wherever this happens on the seafloor, life takes advantage,” said geophysicist Chris German of the Woods Hole Oceanographic Institute. “Every time you find seawater interacting with volcanic rock, there’s weird and wonderful life associated with it.” [Wired]
Trinidad, the larger island of the Caribbean duo Trinidad and Tobago, is home to Pitch Lake. This 100-acre pool of hot liquid asphalt is the largest of its kind on our planet, but microbiologist Steven Hallam thought it could tell us something about another world: the Saturnian moon of Titan. If anything could live in the toxic stew of Lake Pitch, he thought, perhaps there’s hope for the hydrocarbon lakes and rivers of that distant moon. He found that the earthly lake teems with life. “Water is scarce in the lake and certainly below the levels normally thought of as a threshold for life to exist,” he says. “Yet on average, each gram of ‘goo’ in the lake contains tens of millions of living cells” [Australian Broadcasting Corporation].