Curio Cabinet

The Earth is teeming with life and, apparantly, with “not-life” as well. Scientists have discovered a new type of organism that appears to defy the standard definition of “life.” All living things are organisms, but not all organisms are living. Take viruses, for instance. While viruses are capable of reproducing, they can’t do so on their own. They require a host organism to perform the biological functions necessary to reproduce. Viruses also can’t produce energy on their own or grow, unlike even simple living things, like bacteria. Now, there’s the matter of Sukunaarchaeum mirabile. The organism was discovered by accident by a team of Canadian and Japanese researchers who were looking into the DNA of Citharistes regius, a species of plankton. When they noticed a loop of DNA that didn’t belong to the plankton, they took a closer look and found Sukunaarchaeum. In some ways, this new organism resembles a virus. It can’t grow, produce energy, or reproduce on its own, but it has one distinct feature that sets it apart: it can produce its own ribosomes, messenger RNA, and transfer RNA. That latter part makes it more like a bacterium than a virus.
 
Then there’s the matter of its genetics. Sukunaarchaeum, it seems, is a genetic lightweight with only 238,000 base pairs of DNA. Compare that to a typical virus, which can range from 735,000 to 2.5 million base pairs, and the low number really stands out. Nearly all of Sukunaarchaeum’s genes are made to work toward the singular goal of replicating the organism. In a way, Sukunaarchaeum appears to be somewhere between a virus and a bacteria in terms of how “alive” it is, indicating that life itself exists on a spectrum. In science, nothing is as simple as it first appears.

Don’t hold your breath for moon dust. Long thought to be toxic, new research shows that moon dust may be relatively harmless compared to what’s already here on Earth. While the dusty surface of the moon looks beautiful and its name sounds like a whimsical ingredient in a fairy tale potion, it was a thorn in the side of lunar explorers during the Apollo missions. NASA astronauts who traversed the moon’s dusty surface reported symptoms like nasal congestion and sneezing, which they began calling “lunar hay fever.” They also reported that moon dust smelled like burnt gunpowder, and while an unpleasant smell isn’t necessarily bad for one’s health, it couldn’t have been comforting. These symptoms were likely caused by the abrasive nature of moon dust particles, which are never smoothed out by wind or water the way they would be on Earth. The particles are also small, so they’re very hard to keep out of spacesuits and away from equipment. Then there’s the matter of the moon’s low gravity, which allows moon dust to float around for longer than it would on Earth, making it more likely to penetrate spacesuit’s seals and be inhaled into the lungs. There, like asbestos, the dust can cause tiny cuts that can lead to respiratory problems and even cancer…at least, that’s what everyone thought until recently. Researchers at the University of Technology Sydney (UTS) just published a paper claiming that moon dust might not be so dangerous after all. They believe that the dust will likely cause short-term symptoms without leading to long-term damage. Using simulated moon dust and real human lungs, they found that moon dust was less dangerous than many air pollutants found on Earth. For instance, silica (typically found on construction sites) is much more dangerous, as it can cause silicosis by lingering in the lungs, leading to scarring and lesions. Astronauts headed to the moon in the future can breathe a sigh of relief—but it may be safer to wait until they get there.

 
[Image description: A moon surrounded by orange-ish hazy clouds against a black sky.] Credit & copyright: Cbaile19, Wikimedia Commons. This file is made available under the Creative Commons CC0 1.0 Universal Public Domain Dedication.

When the fungi kicked ash, the ash started fighting back. For over a decade, ash trees in the U.K. have been under threat from a deadly fungus. Now, the trees appear to be developing a resistance. No matter where they grow, ash trees just can’t seem to catch a break. Invasive emerald ash borers started devastating ash trees in North America in the 1990s. Then, around 30 years ago, the fungi Hymenoscyphus fraxineus arrived in Europe, making its way through the continent one forest at a time. Finally, it made its way into the U.K. in 2012. H. fraxineus is native to East Asia and is the cause of chalara, also called ash dieback. It’s particularly devastating to Fraxinus excelsior, better known as European ash, and it has already reshaped much of the U.K.’s landscape. While the fungus only directly kills ash trees, it presents a wider threat to the overall ecology of the affected areas. H. fraxineus also poses an economic threat, since ash lumber is used for everything from hand tools to furniture.
 
When not being felled by fungus or bugs, ash trees are capable of growing in a wide range of conditions, creating a loose canopy that allows sunlight to reach the forest floor. That, in turn, encourages the growth of other vegetation. A variety of insect species and lichen also depend on ash trees for survival. Luckily, for the past few years, researchers have been seeing a light at the end of the fungus-infested tunnel. Some ash trees have started showing signs of fungal resistance, and a genetic analysis has now revealed that the trees are adapting at a faster rate than previously thought. If even a small percentage of ash trees become fully immune to the fungus, it may be just a matter of time before their population is replenished. Ash trees are great at reproducing, as they’re each capable of producing around 10,000 seeds that are genetically distinct from each other. That also means that ash trees may be able to avoid creating a genetic bottleneck, even though their population has sharply declined due to dieback. Still, scientists estimate around 85 percent of the remaining non-immune ash trees will be gone by the time all is said and done. It’s darkest before the dawn, especially in an ash forest.

 
[Image description: An upward shot of ash tree limbs affected with dieback disease against a blue sky. Some limbs still have green leaves, others are bare.] Credit & copyright: Sarang, Wikimedia Commons. The copyright holder of this work has released it into the public domain. This applies worldwide.

They’re turning greenhouse gases into rocky masses. A London-based startup has developed a device that can not only reduce emissions from cargo ships, but turn them into something useful. Cargo ships, as efficient as they are in some ways, still produce an enormous amount of emissions. In fact, they account for roughly three percent of all greenhouse gas emissions globally. Reducing their emissions even a little could have a big environmental impact, and there have been efforts to develop wind-based technology to reduce fuel consumption as well as alternative fuel. In the case of the startup Seabound, their approach is to scrub as much of the carbon from cargo ship exhaust as possible. Their device is the shape and size of a standard shipping container and can be retrofitted onto existing ships. Once in place, it’s filled with quicklime pellets which soak up carbon from the ship’s exhaust. By the time the exhaust makes it out to the atmosphere, 78 percent of the carbon and 90 percent of the sulfur is removed from it. The process also converts quicklime back into limestone, sequestering the carbon.
 
Similar carbon scrubbing technology is already in use in some factories, so the concept is sound, but there are some downsides. The most common method of quicklime production involves heating limestone to high temperatures, which releases carbon from the limestone and creates emissions from the energy required to heat it. There are greener methods to produce quicklime, but supply is highly limited for the time being. In addition, the process requires an enormous quantity of quicklime, reducing the overall cargo capacity of the ships. Meanwhile, some critics believe that such devices might delay the development and adoption of alternatives that could lead to net zero emissions for the shipping industry. It’s not easy charting a course for a greener future.

 
[Image description: A gray limestone formation in grass photographed from above.] Credit & copyright: Northernhenge, Wikimedia Commons. This file is made available under the Creative Commons CC0 1.0 Universal Public Domain Dedication.

Getting rid of plastic is a pain, but what if it was a painkiller? According to a paper published in Nature Chemistry, scientists at the University of Edinburgh in the U.K. have genetically engineered a strain of E. coli that is capable of breaking down plastic and turning it into acetaminophen. It sounds outlandish, but it’s not as crazy as it seems. The E. coli in question isn’t the same type that makes people ill. This strain is capable of carrying out a chemical reaction called a Lossen rearrangement. It’s a phenomenon that has never been observed in nature before, and until now was only seen in harsh laboratory conditions previously thought to be incompatible with life. Yet, when chemists added polyethylene terephthalate (PET), a type of plastic commonly used in food packaging, into a culture of their specially-engineered E. coli, the bacteria used a Lossen rearrangement to turn plastic molecules into acetaminophen.
 
Also known as paracetamol, Acetaminophen is an over-the-counter painkiller that most people have taken at some point, though they might not know that it, too, is a petroleum derivative. Just as it takes a lengthy process to turn crude oil into helpful pills, researchers had to take several steps to get their E coli to produce something useful. First, they took E. coli that could turn PET into para-aminobenzoic acid (PABA), and added genes from mushrooms and soil bacteria that could turn PABA into acetaminophen. The result was a strain of E. coli that could create acetaminophen from PET in less than 24 hours. That’s one headache solved!

 
[Image description: Plastic bottles and other plastic trash in a yellow waste bin.] Credit & copyright: Hyena, Wikimedia Commons. This work has been released into the public domain by its author, Hyena. This applies worldwide.