archaea

Tough as a Tardigrade

Without water, a human can only survive for about 100 hours. But there’s a creature so resilient that it can go without it for decades. This one millimeter animal can survive both the hottest and coldest environments on Earth, and can even withstand high levels of radiation. This is the tardigrade, and it’s one of the toughest creatures on Earth, even if it does look more like a chubby, eight-legged gummy bear. 

Most organisms need water to survive. Water allows metabolism to occur, which is the process that drives all the biochemical reactions that take place in cells. But creatures like the tardigrade, also known as the water bear, get around this restriction with a process called anhydrobiosis, from the Greek meaning life without water. And however extraordinary, tardigrades aren’t alone. Bacteria, single-celled organisms called archaea, plants, and even other animals can all survive drying up.

For many tardigrades, this requires that they go through something called a tun state. They curl up into a ball, pulling their head and eight legs inside their body and wait until water returns. It’s thought that as water becomes scarce and tardigrades enter their tun state, they start synthesize special molecules, which fill the tardigrade’s cells to replace lost water by forming a matrix. 

Components of the cells that are sensitive to dryness, like DNA, proteins, and membranes, get trapped in this matrix. It’s thought that this keeps these molecules locked in position to stop them from unfolding, breaking apart, or fusing together. Once the organism is rehydrated, the matrix dissolves, leaving behind undamaged, functional cells.

Beyond dryness, tardigrades can also tolerate other extreme stresses: being frozen, heated up past the boiling point of water, high levels of radiation, and even the vacuum of outer space. This has led to some erroneous speculation that tardigrades are extraterrestrial beings.

While that’s fun to think about, scientific evidence places their origin firmly on Earth where they’ve evolved over time. In fact, this earthly evolution has given rise to over 1100 known species of tardigrades and there are probably many others yet to be discovered. And because tardigrades are so hardy, they exist just about everywhere. They live on every continent, including Antarctica. And they’re in diverse biomes including deserts, ice sheets, the sea fresh water, rainforests, and the highest mountain peaks. But you can find tardigrades in the most ordinary places, too, like moss or lichen found in yards, parks, and forests. All you need to find them is a little patience and a microscope.

Scientists are now to trying to find out whether tardigrades use the tun state, their anti-drying technique, to survive other stresses. If we can understand how they, and other creatures, stabilize their sensitive biological molecules, perhaps we could apply this knowledge to help us stabilize vaccines, or to develop stress-tolerant crops that can cope with Earth’s changing climate. 

And by studying how tardigrades survive prolonged exposure to the vacuum of outer space, scientists can generate clues about the environmental limits of life and how to safeguard astronauts. In the process, tardigrades could even help us answer a critical question: could life survive on planets much less hospitable than our own?

From the TED-Ed Lesson Meet the tardigrade, the toughest animal on Earth - Thomas Boothby

Animation by Boniato Studio

youtube

What is CRISPR-Cas9?

In popular usage, “CRISPR” (pronounced “crisper”) is shorthand for “CRISPR-Cas9.” CRISPRs are specialized stretches of DNA. The protein Cas9 (or “CRISPR-associated”) is an enzyme that acts like a pair of molecular scissors, capable of cutting strands of DNA.

CRISPR technology was adapted from the natural defense mechanisms of bacteria and archaea (the domain of single-celled microorganisms). These organisms use CRISPR-derived RNA and various Cas proteins, including Cas9, to foil attacks by viruses and other foreign bodies. They do so primarily by chopping up and destroying the DNA of a foreign invader. When these components are transferred into other, more complex, organisms, it allows for the manipulation of genes, or “editing.”

CRISPRs: “CRISPR” stands for “clusters of regularly interspaced short palindromic repeats.” It is a specialized region of DNA with two distinct characteristics: the presence of nucleotide repeats and spacers. Repeated sequences of nucleotides — the building blocks of DNA — are distributed throughout a CRISPR region. Spacers are bits of DNA that are interspersed among these repeated sequences.

psa; 

sam winchester saved the world

sam winchester overcame archangel lucifer, one of the most powerful beings in all of existence, fourth only to michael, god, and death

sam winchester condemned himself to eternal torment with the father of sin and the father of sin’s big brother

and sam winchester told his own brother that it was all going to be okay

and he did it all in a span of almost sixty seconds real time

sam winchester wins

anonymous asked:

If you think about it, Eukaryotes came about because an ancient archaea (/common ancestor of eukaryotes and archaea) vored a bacteria

Microbe of the Week: Geogemma barossii

Last Monday’s microbe hailed from the euphoric zone: the top layer of the ocean that receives enough sunlight for photosynthesis to occur. This week, we’re heading all the way to the bottom. It’s cold, dark, and scary down there, but this little bugger likes it hot!

Geogemma barossii, aka Strain 121 (a name straight out of science fiction, surely)was discovered in the Mothra hydrothermal vent field in the Juan de Fuca ridge, a plate boundary in the northwest Pacific Ocean, 200 miles off the coast of Washington state. Hydrothermal vents are something like miniature underwater volcanoes, and they possess some of the harshest conditions for life on the planet: extreme pressure, temperatures ranging from 60-464 °C (140-867.2 °F), and toxic minerals. Yet, even in such an impossible place, a wide range of organisms make their home, from microbes to octopodes.

Strain 121 is an archaea (remember, I mentioned them in this post?). Archaea are prokaryotes- single-celled organisms without a nucleus, just like bacteria. In fact, they used to be classified in the same kingdom as bacteria, but groundbreaking work by Carl Woese in the ‘70s and '80s demonstrated that archaea are actually less genetically similar to bacteria than animals are to plants and fungi. In other words, your genes are more similar to those of, say, a banana, than an archaeum’s genes are to a bacterium. 

Strain 121 makes its home in the hot, smoky environment of the hydrothermal vents, respiring iron in the same way that we respire oxygen. Before Strain 121 was discovered, it was believed that life could not exist above 113 °C (235.4 °F, the temperature at which Pyrolobus fumarii, another archaea, is able to grow and divide). The existence of Strain 121 revealed that it was possible for an organism to survive ordinary laboratory sterilization techniques: high pressure and steam at 121 °C. In fact, cranking the temperature up to 130 °C still won’t kill Strain 121- just stop it from growing and diving. Fortunately, Strain 121 is not at all pathogenic to humans, as it cannot survive at human body temperature. But, it does suggest the possibility of life in even more extreme conditions, particularly those encountered on other planets. 

Until about 20 years ago, it was thought that archaea could only be found in extreme environments like hydrothermal vents and hot springs. But, as you might have noticed in the diagram of the microbial food web I posted, they’re found in the more hospital parts of the ocean, too. How do they make a living there? More on that in the coming weeks.

anonymous asked:

How would one be a vegan when they really dislike vegetables? I know that sounds stupid, but I'm already a vegetarian for hating the taste of meat. I struggle to get enough iron and protein, even with milk and eggs. I've tried plant sources of protein and iron like spinach, quinoa, and pumpkin seeds, but my sense of taste/smell is so hypersensitive that I find it near impossible to eat vegetables. I try to force myself, but it's just so hard. Any advice?

It doesn’t sound stupid at all! I was extremely picky before I went vegan and the only vegetables I would eat were peas and corn. That’s it. I hated most vegetables, and I still despise very common plants such as onions and bell peppers. Seriously. I will wish death and demise upon anyone who tries to give me onions or bell peppers.

As far as taste goes, the longer you go completely plant-based, the more your taste buds will change. I know that sounds cheesy and weird, but I promise, it’s absolutely true. I used to need to heap sugar and salt on EVERYTHING. Now, I don’t even own sugar (I think I have maple syrup in the fridge) and I only have salt for when I need to gurgle it. I like a lot more vegetables now, including Brussels sprouts, asparagus, and even kale.

Milk and eggs can cause some problems such as too much cholesterol and inducing mucus in the sinuses (that was my big problem when I ate dairy, as I’m very prone to sinus and ear infections). From a health perspective, dairy and eggs aren’t worth the pus and contaminants you’re getting in return. And from an ethical perspective, dairy and eggs are probably the cruelest industries, so cutting them out when you can is very, very worth it.

As long as you’re eating enough calories, and you don’t have any sort of genetic anomaly, you really should be getting more than enough protein. Most people on a standard Western diet actually get twice as much protein as they need, and that can be very harmful to the kidneys. Too much iron can be unhealthful as well, so unless you suffer from iron-deficiency anemia, I would actually be more concerned with going overboard with protein and iron than anything else (unless you have a medical condition or you have menstruation cycles). And if you are truly worried, you can always buy a plant-based protein powder and make daily shakes (or just dump them into water and drink them like that if you’re like me and don’t have the time/energy). Getting blood tests every few months is also very helpful, and can tell you if you really are protein or iron-deficient.

I’ve been vegan for 12 years, and the only vitamin deficiencies I’ve had were with vitamin D and vitamin B12. Vitamin D because I can’t go outside (heat and high pollen count), and B12 because I didn’t supplement for years and vitamin B12 deficiency runs in my family. You really do need to buy a vitamin B12, not because it comes from meat, but because it’s created by soil bacteria and archaea. And with modern farming practices, we no longer eat vegetables straight from the dirt, therefore we need to supplement. Even non-vegans eat B12 supplements, but they do it through animal feed and B12 shots given to farm animals, rather than through the supplement itself. And I don’t know about you, but I’d rather get B12 directly from the lab rather than through animal feed. :)

If you’re really concerned about iron and protein, all I can say is legumes, legumes, legumes! Bean and lentil it up! Seriously, you can’t eat too many of these guys, and you should honestly be eating them at nearly every meal. Personally, I’ve found black lentils to be my favorite (I’m really picky when it comes to my legumes). Find what you normally eat, especially anything soup or pasta-based, and just add canned beans or lentils to it! Chickpeas are also great, and you can add hummus to basically any type of sandwich (or use it as a dip like I do).

Tofu is also a fantastic source of protein and iron, and soy milk is by far my favorite plant milk because it has the highest concentration of iron and protein. If you don’t have a soy allergy, soy is the way to go. People will falsely claim that estrogen-like isoflavones in soy will give you “breasts" and will “feminize” those who eat it, but there is actual estrogen and progesterone in dairy milk. Not only that, but soy can help lower breast and prostate cancer risk, and the same cannot be said with dairy (quite the opposite, actually, as breast and prostate cancer has been strongly linked to dairy). (x) (x)

Do you find it easier to eat ingredients separately? That’s what I do. I don’t like nuts, seeds, or fruits when they’re cooked into things, but I enjoy eating them raw as snacks. Lately I’ve been on a blueberry and walnut kick, where I will eat a bowl of blueberries and walnuts (separately), and I swear it’s helped bring my inflammation down. Plus walnuts have lots of protein.

The wonderful thing about plants - there’s such a huge variety. You can keep searching until you find a few that you like. That’s basically what I do. I’m still a fairly picky vegan, and I don’t make very much money and I don’t know how to cook, but I’ve made it work for many years. You just gotta find what works for you.

Here are some resources for ya! I hope they help!


Vegan on a Budget: 17 Easy & Affordable Recipes

Seven Day Meal Plan

Switch & Ditch (Meat and Dairy Alternatives)

Build a Meal

What Your Plate Should Look Like

Iron-Rich Foods

Protein Powerhouse

25 Delicious Vegan Sources of Protein

Plant-based vs. Meat-based Iron

Iron in the Vegan Diet

Think near-boiling water is too hot to support life? Think again. The geysers and hot springs of Yellowstone National Park host an array of thermophillic, or heat-loving, microorganisms that can tolerate temperatures as high as 175 degrees Fahrenheit. These bacteria, along with other microorganisms like archaea, create the vivid color palettes of some of Yellowstone’s famed springs and geysers, like the Grand Prismatic Spring pictured here.

The blue center is the heart of the spring, where nearly boiling water makes it impossible for anything to survive, resulting in a startlingly blue hue. As the temperature dips farther out from the hot spring’s superheated center, though, more and more kinds of bacteria, fungi, and other microorganisms are able to endure. The different rings of color emanating from the steaming epicenter represent different microbial communities that call the spring home.

The most heat-tolerant cyanobacteria dominate the still-extreme temperatures in the yellow-colored ring, while the outer, orange layer hosts an array of organisms that can’t stand the heat quite as well as their neighbors. The colors of these rings also change in response to the time of year and other environmental factors. The cooler outer rings, meanwhile, form ecosystems of their own, hosting flies, mites, spiders, and other animals. Ephydrid flies feast on the bacterial communities and lay their eggs there, while predators like wolf spiders and parasites such as mites are drawn here because of the presence of the flies.

Find out about more amazing species thriving in exceptional environments in the special exhibition Life at the Limits, open now through January 2016. 

Is anything tough enough to survive on Mars?

Researchers at the University of Arkansas recently took a step toward answering a question for the ages: Is there life on Mars? Answer: they can’t rule it out.

Two recent publications suggest that life, in the form of ancient, simple organisms called methanogens, could survive the harsh conditions found near the surface of Mars, and deep in its soils. Using methanogens to test for survivability is particularly relevant because scientists have detected their byproduct, methane, in the Martian atmosphere. On Earth, methane is strongly associated with organic matter, though there are non-organic sources of the gas, including volcanic eruptions.

Scientists aren’t yet sure what the presence of Martian methane means. But one possibility is that tenacious life flourishes on Mars despite the rocky soil, thin atmosphere and scarcity of liquid water.

Keep reading

Microbiology Final [051616]

It’s the morning of the final and I’m in the library for one last review. 

Happy Finals! 

Crash Course aka. our saviours. 
(other crash course masterposts coming soon!)

—–

Biology 

Chemistry

Anatomy & Physiology

@victeux


There’s a knock on the door, the other standing just in front of it. This was the place he said right? Why did Haedeaus believe this was a good idea- while he was gone dealing with matters he had been neglecting, he chose to throw his responsibility to her. To.. hang out? Isn’t that what he said? How was she supposed to know- social butterfly Archaea may be, but “hip” and “up-to-date”?

She could barely use a flip phone, what did he expect from her?

❝ Excuse me? Is anyone home? I was sent by Haedeaus. ❞