Saturday, July 20News For London

The rising tide of plastic: How bacteria can sustainably eat plastic waste

Will science save our seas? Meet the microorganisms that live off plastic. 

Scientists have discovered a microorganism that can breakdown plastic and essentially, eat it. A microorganism is a living bacterium that can only be seen under a microscope. They can cluster and live in colonies, made up of many microorganisms. 

Humans have always been mass consumers of plastic, but the issue is on the rise. 

In 2020 alone, we produced 367million tonnes of plastic, says Plastics Europe. This is a huge change compared to 2017, with a global production of a mere 8.3million tonnes of plastic. 

It is the mixture between mass production and single use wastage that has led to massive problems, with plastic waste cluttering our oceans. 

Credit: Rachelle Townley

Kohei Oda is a scientist at the Kyoto Institute of Technology. His team took a trip to a recycling plant that only handled plastics made of PET, or polyethylene terephthalate. This kind of plastic makes up drinking bottles and many clothing fibres. 

This plastic is the opposite of sustainable. It is made up of molecules in a long string formation, meaning they are strong, and not suited to being thrown away straight after use. Interestingly, this kind of plastic would be better suited for re-usable items, yet it is the most common form of single-use plastic. 

Kohei Oda and his team sampled the sediment and water contaminated by the PET to test what kind of bacteria had grown on the plastic. They discovered a new bacterium that grew on the PET which consumes it to survive. 

This may be the most effective and exciting discovery in the world of ‘plastic eating’ bacteria, but it is not the first. In the 1990s, researchers found bacterium that fed off plastics, however they would only do so when the material was already biodegradable, or made up of weak structures.

Credit: Rachelle Townley

Scientists are now looking deeper into how the bacterium works. A three dimensional structure has been made to get an idea of what PET structurally looks like, showing how it evolves and moves. They concluded that the make-up of the bacterium is what makes it effective at eating through plastics.

Research is now being pushed further. Scientists are cultivating and modifying the PET enzyme so they have enough to introduce it on a commercial scale. They may one day be able to release it into recycling plants to increase the speed at which plastic breaks down.

It may actually be environmental factors that are causing bacteria to develop the taste for waste. It has been found that bacteria growing in dirty areas, crowded with plastic waste, is more likely to naturally degrade plastic quicker than those found in clean areas. This is because it creates a breeding ground for the bacteria to multiply rapidly.

Credit: Rachelle Townley

Research has been limited to academic institutions rather than practical use, however, people are now trying to change this. It is important to find a use for the plastic eating enzyme so we can reduce the problem of waste on our shores. 

Beaches are filled with bottles and food wrappers that people have dropped after not finding a suitable litter bin. It is not just an eyesore, but also a killer. Globally, turtles are the most common animals found dead, washed up on shores, stomachs lined with plastic. 

It is clear why we need to revolutionise the way we recycle plastic. 

The future is in PET recycling techniques. We look to science to predict the next generation of recycling. France is paving the way in this technology. A pilot recycling plant has been created to utilise the PET microorganism found in the original test site to see how it would work on a large scale. 

Scientists believe that these pilot recycling plants will be popping up all over the globe. To minimise costs of having to mix traditional recycling with PET recycling, manufacturers should start producing products using plastics that can only be degraded with PET organisms. 

Even though this enzyme has been discovered, to be able to overall reduce the amount of litter created in the first place, we should all be more diligent in disposing of our rubbish in a responsible way. 

Credit: Rachelle Townley

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