Researchers accidentally engineer plastic-eating enzyme

A boy stands near a whale-shaped art installation that is made of plastic and trash made by environmental activist group Greenpeace Philippines, lying along the shore in Naic, Cavite in the Philippines, in this May 12, 2017 file photo. (REUTERS)
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.”
 


Scientists create bee vaccine to fight off ‘insect apocalypse’

Photo taken on August 2, 2018 shows a bee collecting pollen from a flower in Kirkkonummi, Finland. Scientists in Finland have developed what they believe is the world's first vaccine to protect bees against disease, raising hopes for tackling the drastic decline in insect numbers which could cause a global food crisis. (AFP)
Updated 16 December 2018
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Scientists create bee vaccine to fight off ‘insect apocalypse’

  • The vaccine, developed by a team at Helsinki University in Finland, works by giving bees resistance to fight off severe microbial diseases that can be fatal for pollinator communities

HELSINKI: Scientists in Finland have developed what they believe is the world’s first vaccine to protect bees against disease, raising hopes for tackling the drastic decline in insect numbers which could cause a global food crisis.
Bees are vital for growing the world’s food as they help fertilize three out of four crops around the globe, by transferring pollen from male to female flowers.
But in recent years bee populations around the world have been dying off from “colony collapse disorder,” a mysterious scourge blamed on mites, pesticides, virus, fungus, or some combination of these factors.
UN-led research in 2016 found that more than 40 percent of invertebrate pollinators, particularly bees and butterflies, are facing extinction.
The study also found that 16.5 percent of vertebrate pollinators, such as birds and bats, are under threat.
Scientists warn that the die-off will result in higher food prices and the risk of shortages.

The vaccine, developed by a team at Helsinki University in Finland, works by giving bees resistance to fight off severe microbial diseases that can be fatal for pollinator communities.
“If we can save even a small part of the bee population with this invention, I think we have done our good deed and saved the world a little bit,” lead researcher Dalial Freitak said.
“Even a two-to-three percent increase in the bee population would be humongous,” she told AFP.
Vaccinating insects was previously thought to be impossible because the creatures lack antibodies, one of the key mechanisms humans and other animals use to fight disease.
But a breakthrough came in 2014 when Freitak, a specialist in insects and immunology, noticed that moths who are fed certain bacteria can in fact pass on immunity to their offspring.
“They could actually convey something by eating. I just didn’t know what the mechanism was,” Freitak said.
“I met with Heli Salmela, who was working on honey bees and a protein called vitellogenin. I heard her talk and I was like, ‘OK, I could make a bet that it is your protein that takes my signal from one generation to another’.”
The pair started to collaborate and created a vaccine against American foulbrood, the most globally widespread and destructive bee bacterial disease.
The treatment is administered to the queen bee via a sugar lump, similar to the way many children are given polio vaccines. The queen then passes the immunity to her offspring, spreading it through the bee community.
As well as working on vaccines against further diseases, the team has also begun trying to raise funding to make the vaccine commercially available, with “very positive” feedback so far, according to Freitak.
“There are many regulatory hurdles. Four to five years until reaching the market is an optimistic estimate,” she said.

Diseases are believed to be just one of a number of reasons for the loss of pollinators, alongside pesticides and intensive farming, which reduces the diversity of insects’ nutrition.
But the team believes that protecting bee populations against disease will make them stronger, and therefore better able to withstand the other threats.
The European Union and Canada have voted to introduce bans on insecticides based on neonicotinoids after studies showed the chemicals harmed the ability of bees to reproduce.
UN-backed research in 2016 estimated that up to $577 billion (511 billion euros) worth of food grown every year relies directly on pollinators.
The study said the volume of food produced that depends on pollinators has risen by 300 percent in the last half century.
As pollinator numbers have declined, some farmers have turned to either renting bees or pollinating by hand — as with fruit trees in some parts of China — in order to replace the processes that nature previously provided free of charge.
In Helsinki the project relied on external funding, but the team has now taken up a more secure tenure at Graz University in Austria, where further research on vaccinations will begin early next year.
Graz is also the previous seat of noted zoologist Karl von Frisch, whose discovery that honey bees communicate by performing the figure-of-eight “waggle dance” won him the Nobel Medicine Prize in 1973.