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Scientists Accidentally Make Plastic-Eating Bacteria Even More Efficient

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In 2016, Japanese researchers discovered a type of bacteria that eats non-biodegradable plastic. The organism, named Ideonella sakaiensis, can break down a thumbnail-sized flake of polyethylene terephthalate (PET), the type of plastic used for beverage bottles, in just six weeks. Now, The Guardian reports that an international team of scientists has engineered a mutant version of the plastic-munching bacteria that's 20 percent more efficient.

Researchers from the U.S. Department of Energy's National Renewable Energy Laboratory and the University of Portsmouth in the UK didn't originally set out to produce a super-powered version of the bacteria. Rather, they just wanted a better understanding of how it evolved. PET started appearing in landfills only within the last 80 years, which means that I. sakaiensis must have evolved very recently.

The microbe uses an enzyme called PETase to break down the plastic it consumes. The structure of the enzyme is similar to the one used by some bacteria to digest cutin, a natural protective coating that grows on plants. As the scientists write in their study published in the journal Proceedings of the National Academy of Sciences, they hoped to get a clearer picture of how the new mechanism evolved by tweaking the enzyme in the lab.

What they got instead was a mutant enzyme that degrades plastic even faster than the naturally occurring one. The improvement isn't especially dramatic—the enzyme still takes a few days to start the digestion process—but it shows that I. sakaiensis holds even more potential than previously expected.

"What we've learned is that PETase is not yet fully optimized to degrade PET—and now that we've shown this, it's time to apply the tools of protein engineering and evolution to continue to improve it," study coauthor Gregg Beckham said in a press statement.

The planet's plastic problem is only growing worse. According to a study published in 2017, humans have produced a total of 9 billion tons of plastic in less than a century. Of that number, only 9 percent of it is recycled, 12 percent is incinerated, and 79 percent is sent to landfills. By 2050, scientists predict that we'll have created 13 billion tons of plastic waste.

When left alone, PET takes centuries to break down, but the plastic-eating microbes could be the key to ridding it from the environment in a quick and safe way. The researchers believe that PETase could be turned into super-fast enzymes that thrives in extreme temperatures where plastic softens and become easier to break down. They've already filed a patent for the first mutant version of the enzyme.

[h/t The Guardian]

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6 Signs You're Getting Hangry
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Hangry (adjective): Bad-tempered or irritable as a result of hunger. This portmanteau (of hungry and angry) is not only officially recognized as a word by the Oxford English Dictionary, but it's also recognized by health experts as a real physiological state with mood-altering consequences.

That hangry feeling results from your body's glucose level dropping, putting you into a state of hypoglycemia, or low blood sugar. Glucose is the body's primary source of energy, so when you don't have enough, it affects your brain and other bodily functions, including the production of the hormones insulin and glucagon, which help regulate blood sugar. Check out the symptoms below to see if you've crossed over into the hanger danger zone.

1. IT TAKES EVERYTHING IN YOUR POWER JUST TO KEEP YOUR EYES OPEN.

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Glucose equals energy, so when your blood sugar levels are low, you may start wishing you were back in bed with the shades drawn. If you start feeling sluggish or tired even though you’re well-rested, you might just need to eat something.

2. THE EASIEST ITEM ON YOUR TO-DO LIST SEEMS LIKE AN IMPOSSIBLE TASK …

It’s hard to concentrate when all you can think about is whether you're going to order the fish or beef tacos for lunch. The distraction goes beyond fantasies about food, though. The brain derives most of its energy from glucose, so when it's low on fuel, a serious case of brain fog can set in. Confusion and difficulty speaking are among the more serious symptoms you may experience when you're hangry.

3. … AND YOU HAVE A BAD CASE OF WORD VOMIT.

Blame this on brain fog too. The gray matter in your noggin goes a little haywire when blood sugar is in short supply. That's why you may start stuttering or slurring your words. You might also have difficulty finding your words at all—it can feel like your mouth and brain are disconnected.

4. YOU’RE SHAKING LIKE A LEAF AND FEEL LIGHTHEADED.

Tremors and dizziness are both signs that you should pay closer attention to your body, which is screaming, "Feed me!" Once again, low blood sugar is often the culprit of trembling hands and feeling faint, and exhaustion and stress make the symptoms worse.

5. YOUR COWORKERS SEEM ESPECIALLY ANNOYING.

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You’re tense and irritable, and it’s starting to show. Hunger causes your body to release cortisol and adrenaline, the same hormones responsible for stress. This can put you on edge and lower your tolerance for other people’s quirks and irksome habits, which suddenly seem a lot less bearable.

6. YOU SNAPPED AT YOUR FRIEND OR PARTNER FOR NO GOOD REASON.

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Not only are you irritable, but you’re more likely to lash out at others because of it. The doses of adrenaline and cortisol in your body can induce a fight-or-flight response and make you go on the attack over matters that—if you had some food in you—would seem unimportant.

So what should you do if these descriptions sound all too familiar? Eat a snack, pronto—one with complex carbohydrates, lean protein, and healthy fats. The first one brings up your blood sugar level, and the other two slow down how fast the carbohydrates are absorbed, helping you to avoid a sugar crash and maintain a normal blood sugar level. Eating small meals every few hours also helps to keep hanger at bay.

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Astronomers Discover 12 New Moons Around Jupiter
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As the largest planet with the largest moon in our solar system, Jupiter is a body of record-setting proportions. The fifth planet from the Sun also boasts the most moons—and scientists just raised the count to 79.

A team of astronomers led by Scott S. Sheppard of the Carnegie Institute for Science confirmed the existence of 12 additional moons of Jupiter, 11 of which are “normal” outer moons, according to a statement from the institute. The outlier is being called an “oddball” for its bizarre orbit and diminutive size, which is about six-tenths of a mile in diameter.

The moons were first observed in the spring of 2017 while scientists looked for theoretical planet beyond Pluto, but several additional observations were needed to confirm that the celestial bodies were in fact orbiting around Jupiter. That process took a year.

“Jupiter just happened to be in the sky near the search fields where we were looking for extremely distant solar system objects, so we were serendipitously able to look for new moons around Jupiter while at the same time looking for planets at the fringes of our solar system,” Sheppard said in a statement.

Nine of the "normal" moons take about two years to orbit Jupiter in retrograde, or counter to the direction in which Jupiter spins. Scientists believe these moons are what’s left of three larger parent bodies that splintered in collisions with asteroids, comets, or other objects. The two other "normal" moons orbit in the prograde (same direction as Jupiter) and take less than a year to travel around the planet. They’re also thought to be chunks of a once-larger moon.

The oddball, on the other hand, is “more distant and more inclined” than the prograde moons. Although it orbits in prograde, it crosses the orbits of the retrograde moons, which could lead to some head-on collisions. The mass is believed to be Jupiter’s smallest moon, and scientists have suggested naming it Valetudo after the Roman goddess of health and hygiene, who happens to be the great-granddaughter of the god Jupiter.

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