What you might have missed: ancient microbes, digesting silicone and a new snake

New species of coffee snake

Scientists have described a new species of snake from the cloud forests of Ecuador in a paper published in the journal Evolutionary Systematics.

Close up photo of coffee snake
Ninia guytudori. Credit: Alejandro Arteaga

The species, named Ninia guytudori, or Tudor’s coffee-snake, honours naturalist and scientific illustrator Guy Tudor for his impact on the conservation of South America’s birds.

The snake is endemic to the Pacific slopes of the Andes in northwestern Ecuador, where it lives between 1,000-1,500 meters above sea level. Like other coffee snakes, Tudors’s Coffee-Snakeoften inhabits coffee plantations, especially in areas where its cloud forest habitat has been destroyed. 

“This is species number 30 that I have discovered, out of a target of 100,” says first author Alejandro Arteaga, a biologist and president of the Khamai Foundation, an ecological not-for-profit based in Ecuador.

Photo of dark brown snake
Ninia guytudori from Santa Lucía Cloud Forest Reserve, Pichincha province. Credit: Jose Vieira

Scientists find traces of ancient microbial metabolism in 3 billion year old rock

The first life forms to emerge on Earth were microorganisms. Now new research has found evidence that complex microbial communities already existed 3.42 billion years ago, during the Palaeoarchaean period.

Researchers analysed samples of the Barberton greenstone belt, a mountain range in South Africa whose rocks are among the oldest on the Earth’s surface.

“By discovering carbonaceous matter in primary pyrite crystals and analysing carbon and sulphur isotopes in these materials, we were able to distinguish individual microbial metabolic processes,” says Henrik Drake, a geochemist and geobiologist from Linnaeus University in Sweden, and senior author of a new paper in Precambrian Research.

These communities probably consisted of microorganisms that used sunlight, and metabolised sulphur, for energy, and produced methane or acetate.

“We didn’t expect to find traces of so many microbial metabolic processes,” says first author Dr Manuel Reinhardt, an expert on paleo ecosystems from the University of Göttingen in Germany.

“Our findings significantly advance the understanding of ancient microbial ecosystems and open up new avenues for research in the field of palaeobiology.”

Forget plastic, now we have an enzyme that attacks silicone

Enzymes that can digest plastic have been drawing a lot of attention from scientists in recent years. Now, US researchers have engineered a protein that can attack another lingering substance: silicone.

The team is led by Professor Frances Arnold, winner of the 2018 Nobel Prize for Chemistry for her work on “directed evolution”: using artificial lab-based selection to coax enzymes into performing functions.

Now, the research has yielded an enzyme that breaks the carbon-silicon bond in siloxanes, the substances that make silicones. Silicones are anthropogenic and so don’t degrade naturally in the environment – instead, they can build up in places like plastic, or break apart into dangerous contaminants.

The researchers have published a description of their silicone-breaking enzyme in Science.

“Nature is an amazing chemist, and her repertoire now includes breaking bonds in siloxanes previously thought to evade attack by living organisms,” says Arnold.

Computer generated image of enzyme
An artist’s depiction of an artificially evolved enzyme breaking a silicon-carbon bond. Credit: Caltech/Dow

How HIV gets into the centre of cells

Australian scientists have cracked the mystery of how the human immunodeficiency virus (HIV) gets into the nucleus of cells to establish infection.

“There’s something special about HIV; it can penetrate the nucleus without damaging it or needing to wait for the cell to divide like other viruses. Our observations give us insight that allows us to think about how we deliver cargo into the nucleus,” says David Jacques, a medical researcher from the University of New South Wales and senior author of a paper in Nature.

The study found HIV’s protective protein coat, the capsid, has evolved to interact with the host’s nuclear pore complex – barrier proteins that allow small molecules to pass in and out of the nucleus. It does this in the same way that host chaperone proteins do when carrying larger molecules across.

“It’s as though the viral capsid has learned the secret handshake to be permitted into a restricted area by mimicking the chaperones,” adds Jacques.

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