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Plastic pollution: This tiny worm can dissolve plastic bags with its drool

Plastic pollution: This tiny worm can dissolve plastic bags with its drool

A tiny wax worm can dissolve plastic pollution with its saliva, new research has found.

Plastic can take up to 1000 years to decompose, clogging up landfill and polluting the ocean.

But climate campaigners have recruited an unlikely new ally in their fight to reduce this waste – wax worms, the moth larvae that infest beehives.

The worm’s saliva contains two enzymes that can degrade polyethylene, a tough material used in plastic bags and bottles.

According to Spanish researchers, one hour’s exposure to the worm’s saliva degrades the material as much as years of weathering.

The impetus for the study came in 2017 when a scientist – and amateur beekeeper – was cleaning out an infested hive.

The larvae had started eating holes in a plastic refuse bag.

“To the best of our knowledge, these enzymes (in the saliva) are the first animal enzymes with this capability, opening the way to potential solutions for plastic waste management through bio-recycling/up-cycling,” the research report – published in Nature this month – reads.

 

Scientists have discovered that enzymes in wax worm saliva dissolve plastic

 

How bad is plastic for the planet?

Humans have littered the entire planet with damaging plastic debris.

The hardy material takes millions of years to decompose. Of the 10 billion tonnes of plastic that have ever been created, a whopping 6 billion sits in landfill sites or pollute the environment.

This has a devastating impact on wildlife – more than 90 per cent of the world’s seabirds have plastic in their guts.

Recycling can help mitigate some of the worst effects of plastics. Yet a 2022 report by the Organisation for Economic Co-operation and Development (OECD) found that just 9 per cent of plastic is successfully recycled.

This is where the wax worms come in. They can help dissolve polyethylene, which accounts for roughly 30 per cent of plastic production worldwide.

Wax worms aren’t the only solution that scientists have come up with to combat our ever-growing plastic problem.

 

Plastic-munching superworms

From eating less meat to buying local ingredients, there are lots of ways to make environmentally friendly food choices. And according to a 2022 Australian study, certain types of worms can adopt an eco-diet too – but not in the way you might think.

Queensland scientists have discovered that the Zophobas morio – a type of beetle larvae commonly known as a superworm – can survive on polystyrene alone.

Over three weeks, the research team fed three groups of superworms different diets.

The worms on the plastic diet acted like “mini recycling plants,” lead author Dr Chris Rinke explains, destroying the plastic with their unique gut enzymes.

They even put on weight in the process.

“[The superworms] shred the polystyrene with their mouths and then fed it to the bacteria in their gut,” says Dr Rinke.

If scientists can work out how to grow the gut enzyme in a lab, they could use it to dissolve plastics on a mass scale, forming these byproducts into bioplastics.

“We can then look into how we can upscale this process to a level required for an entire recycling plant,” said Co-author of the research, PhD candidate Jiarui Sun.

Given that polystyrene accounts for around one-tenth of all non-fibrous plastics, this would be a significant breakthrough.

 


 

Source euronews.green

 

 

This is how worms could help to eat up the planet’s plastic pollution.

This is how worms could help to eat up the planet’s plastic pollution.
  • Research has found mealworms can eat plastic and still be nutritious as food for other animals.
  • Even those that ate Styrofoam, which contains a toxic chemical, seemed to show no adverse side-effects and the chemical didn’t build up in its body.

New findings suggest mealworms could be the solution to our big plastic problem.

They can not only consume various forms of plastic, but also Styrofoam containing a common and toxic chemical additive. And even after that meal, they can serve as protein-rich feedstock for other animals.

The study is the first to look at where chemicals in plastic end up after being broken down in a natural system—a yellow mealworm’s gut, in this case. It serves as a proof of concept for deriving value from plastic waste.

“This is definitely not what we expected to see,” says Anja Malawi Brandon, a PhD candidate in civil and environmental engineering at Stanford University and lead author of the paper in Environmental Science & Technology.

 

The process of how meal worms could help to minimize plastic waste.
Image: Environmental Science and Technology

 

“It’s amazing that mealworms can eat a chemical additive without it building up in their body over time.”

Mealworms as animal food

In earlier work, researchers revealed that mealworms, which are easy to cultivate and widely used as a food for animals ranging from chickens and snakes to fish and shrimp, can subsist on a diet of various types of plastic.

They found that microorganisms in the worms’ guts biodegrade the plastic in the process—a surprising and hopeful finding. However, concern remained about whether it was safe to use the plastic-eating mealworms as feed for other animals given the possibility that harmful chemicals in plastic additives might accumulate in the worms over time.

“This work provides an answer to many people who asked us whether it is safe to feed animals with mealworms that ate Styrofoam“, says Wei-Min Wu, a senior research engineer in the civil and environmental engineering department.

The researchers looked at Styrofoam or polystyrene, a common plastic typically used for packaging and insulation that is costly to recycle because of its low density and bulkiness.

It contains a flame retardant called hexabromocyclododecane, or HBCD, commonly added to polystyrene. The additive is one of many used to improve plastics’ manufacturing properties or decrease flammability.

Plastic, worms, shrimp

In 2015 alone, nearly 25 million metric tons of these chemicals were added to plastics, according to various studies. Some, such as HBCD, can have significant health and environmental impacts, ranging from endocrine disruption to neurotoxicity. Because of this, the European Union plans to ban HBCD, and US Environmental Protection Agency is evaluating its risk.

Mealworms in the experiment excreted about half of the polystyrene they consumed as tiny, partially degraded fragments and the other half as carbon dioxide. With it, they excreted the HBCD—about 90% within 24 hours of consumption and essentially all of it after 48 hours.

Mealworms fed a steady diet of HBCD-laden polystyrene remained as healthy as those eating a normal diet. The same was true of shrimp fed a steady diet of the HBCD-ingesting mealworms and their counterparts on a normal diet. The plastic in the mealworms’ guts likely played an important role in concentrating and removing the HBCD.

The researchers acknowledge that mealworm-excreted HBCD still poses a hazard, and that other common plastic additives may have different fates within plastic-degrading mealworms. While hopeful for mealworm-derived solutions to the world’s plastic waste crisis, they caution that lasting answers will only come in the form of biodegradable plastic replacement materials and reduced reliance on single-use products.

“This is a wake-up call,” Brandon says. “It reminds us that we need to think about what we’re adding to our plastics and how we deal with it.”