Mass seal deaths in Russia’s Lake Baikal

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A handout picture taken on Sept. 20, 2015 and provided by Oleg Timoshkin, biologist at the Russian Academy of Sciences’ Limnological Institute in Irkutsk, shows Spirogyra algae in the waters of Lake Baikal. Lake Baikal is undergoing its gravest crisis in recent history, experts say, as the government bans the catching of a signature fish that has lived in the world’s deepest lake for centuries but is now under threat. (AFP photo Russian Academy of Sciences’ Limnological Institute in Irkutsk/Oleg Timoshkin)
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A handout picture taken on Sept. 20, 2015 and provided by Oleg Timoshkin, biologist at the Russian Academy of Sciences’ Limnological Institute in Irkutsk, shows totting Spirogyra algae on the beach of Lake Baikal. Lake Baikal is undergoing its gravest crisis in recent history, experts say, as the government bans the catching of a signature fish that has lived in the world’s deepest lake for centuries but is now under threat. (AFP photo Russian Academy of Sciences’ Limnological Institute in Irkutsk/Oleg Timoshkin)
Updated 31 October 2017
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Mass seal deaths in Russia’s Lake Baikal

MOSCOW: Around 130 dead seals have washed up on the shores of Russia’s Lake Baikal, authorities said Tuesday, as they launched a probe into the latest problem to hit the world’s deepest lake.
The Baikal seal is the smallest in the world, and exactly how and when the species colonized the ancient Siberian lake is still a mystery.
“There were about 130 animals found dead” over the past few days, said environmental ministry spokesman Nikolai Gudkov.
“We took water samples to understand whether we can talk of water pollution as the reason,” he told AFP, though results have not yet been processed.
Scientists have also taken biopsies of the animals, he said.
The animal is not endangered and Gudkov said the species’ population has actually increased in recent years, growing to around 130,000.
Preliminary theories about the die-off did not suggest pollution is the reason, he added.
Lake Baikal, a UNESCO World Heritage Site which has thousands of endemic species, has been suffering from a string of detrimental phenomena over recent years.
These include depletion of fish stocks, death of endemic sponges and explosion of growth of Spirogyra algae unnatural to the lake which scientists say is caused by pollution.


Researchers accidentally engineer plastic-eating enzyme

Updated 17 April 2018
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Researchers accidentally engineer plastic-eating enzyme

  • Despite recycling efforts, most plastic can persist for hundreds of years in the environment
  • Researchers say they are now working on further improvements to the enzyme

TAMPA: Researchers in the US and Britain have accidentally engineered an enzyme which eats plastic and may eventually help solve the growing problem of plastic pollution, a study said Monday.
More than eight million tons of plastic are dumped into the world’s oceans every year, and concern is mounting over this petroleum-derived product’s toxic legacy on human health and the environment.
Despite recycling efforts, most plastic can persist for hundreds of years in the environment, so researchers are searching for better ways to eliminate it.
Scientists at the University of Portsmouth and the US Energy Department’s National Renewable Energy Laboratory decided to focus on a naturally occurring bacterium discovered in Japan a few years ago.
Japanese researchers believe the bacterium evolved fairly recently in a waste recycling center, since plastics were not invented until the 1940s.
Known as Ideonella sakaiensis, it appears to feed exclusively on a type of plastic known as polyethylene terephthalate (PET), used widely in plastic bottles.

The researchers’ goal was to understand how one of its enzymes — called PETase — worked, by figuring out its structure.
“But they ended up going a step further and accidentally engineered an enzyme which was even better at breaking down PET plastics,” said the report in the Proceedings of the National Academy of Sciences, a peer-reviewed US journal.
Using a super-powerful X-ray, 10 billion times brighter than the Sun, they were able to make an ultra-high-resolution three-dimensional model of the enzyme.
Scientists from the University of South Florida and the University of Campinas in Brazil did computer modeling which showed PETase looked similar to another enzyme, cutinase, found in fungus and bacteria.
One area of the PETase was a bit different, though, and researchers hypothesized that this was the part that allowed it to degrade man-made plastic.
So they mutated the PETase active site to make it more like cutinase, and unexpectedly found that this mutant enzyme was even better than the natural PETase at breaking down PET.
Researchers say they are now working on further improvements to the enzyme, with the hope of eventually scaling it up for industrial use in breaking down plastics.
“Serendipity often plays a significant role in fundamental scientific research, and our discovery here is no exception,” said study author John McGeehan, professor in the School of Biological Sciences at Portsmouth.
“Although the improvement is modest, this unanticipated discovery suggests that there is room to further improve these enzymes, moving us closer to a recycling solution for the ever-growing mountain of discarded plastics.”