Curio Cabinet

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.

Beware the pharaoh’s… cure? A deadly fungus that once “cursed” those who entered the tomb of King Tutankhamun has been engineered into a treatment for cancer by researchers at the University of Pennsylvania. When a team of archaeologists opened up King Tutankhamun’s fabled tomb back in 1922, they couldn’t have known about the terrible fate they had been dealt. One by one, those who entered the tomb died from an unknown illness. Then, in the 1970s, a similar string of tragedies befell those who entered the 15th century tomb of King Casimir IV in Poland. One such incident might have been dismissed as an unfortunate accident, but two meant that there was something else at play. Despite speculation about ancient curses, the likely culprit was found to be a fungus called Aspergillus flavus. It’s capable of producing spores that can stay alive seemingly indefinitely, and the spores contain toxins that are deadly when inhaled by humans. As they say, though, it’s the dose that makes the poison. In this case, the proper dose can instead be a cure. Researchers studying the deadly toxins within the fungal spores found a class of compounds called RiPPs (ribosomally synthesized and post-translationally modified peptides) which are capable of killing cancer cells. Moreover, the compounds seem to be able to target only cancer cells without affecting healthy ones. That’s a huge improvement over conventional treatments like chemotherapy, which can harm a variety of healthy cells as much as they harm cancer. Another interesting fact is that the compounds can be enhanced by combining them with lipid molecules like those found in royal jelly (the special honey that is fed exclusively to queen bees), making it easier for them to pass through cell membranes. Fungus and honey coming together to cure cancer? Sounds like a sweet (and savory) deal.

 
[Image description: A petri dish containing a culture of the fungus Aspergillus flavus against a black background. The fungus appears as a white-ish circle.] Credit & copyright: CDC Public Health Image Library, Dr. Hardin. This image is in the public domain and thus free of any copyright restrictions.