Scientists are developing an artificial 'worm intestine' to break down plastics

Plastic waste poses a huge burden on ecosystems, because it is not biodegradable, which means it remains, accumulating and in the long term, a major problem for the environment.

It is known that traditional methods of getting rid of the accumulation of plastic waste rely on burning or burying waste, which are methods that contribute to greenhouse gas emissions and soil pollution.

To solve the problem of the accumulation of plastic waste in ecosystems, scientists have turned to creating new types of plastic that are able to decompose environmentally and do not produce waste over a relatively long period of time, or to dispose of them by using insects and fungi that devour plastic or other solutions derived from nature.

A solution from nature

Among these methods that scientists have invented in recent years is the use of enzymes and insects that eat plastic, including fungi that digest plastic in swamps, or some types of larvae that can live on plastic products. But to take advantage of these plastic-eating organisms, scientists will need to be able to reproduce them in large numbers, which is a problem they have been facing.

According to the study , the results of which were published in the journal Science Direct, a team of scientists from Nanyang Technological University and the Singapore Center for Environmental Life Sciences Engineering in Singapore were able to devise a new method for eliminating plastic waste inspired by nature, and relying on the use of the intestinal microbes of worms to treat plastic waste. By developing an artificial "worm intestine" that can break down plastics without the need for large-scale worm breeding, this method also accelerates the biodegradation process of plastics and offers a promising solution to the plastic waste problem.

Dark beetle worms

According to the statement issued by Nanyang Technological University in Singapore, previous studies have shown that the dark beetle worms, which are commonly sold as pet food and are known as “superworms” for their nutritional value; They can survive on a diet of plastic, because their gut contains bacteria capable of breaking down common plastics.

The statement adds that despite this characteristic of smart beetle worms, their use in processing plastic is not applicable, because the worms eat plastic and decompose it slowly, and their reproduction in large numbers requires a lot of maintenance and care.

To overcome this problem, the scientific team isolated wormy intestinal bacteria to do this task without the need to reproduce the worms on a large scale.

"One smart beetle worm can consume a few milligrams of plastic in its lifetime, so imagine how many worms would be needed if we were to rely on them to process plastic waste," says Nanyang University associate professor Cao Bin. "That's why we have our method that eliminates the slow decomposition of plastic." “And also the need to reproduce worms in large numbers, by focusing on enhancing beneficial microbes in the worm’s intestines and building an artificial worm intestine that can efficiently decompose plastic materials.”

Development of a plastic-digesting intestine

To create a plastic-digesting worm's gut, scientists fed three groups of superworms diets of three types of plastic — high-density polyethylene, polypropylene, and polystyrene — over the course of 30 days, says the press release from Nanyang University.

These plastic materials are then chosen to be among the most common plastic materials used in daily items, such as food boxes and detergent bottles, including high-density polyethylene, a type of plastic known for its high resistance to shocks, which makes it difficult to break.

After feeding the worms plastic, the scientists extracted microbiomes from their intestines and collected them in vials containing artificial nutrients and different types of plastic, forming an artificial “worm gut.” Over the course of six weeks, the microbes were left to grow in the flasks at room temperature.

She then showed the flasks containing gut microbes from worms that fed on the plastic; Significant increase in plastic-degrading bacteria.

There is no small package, no small package, no small package, but then the package is in the same package.

Furthermore, the microbial communities colonizing the plastics in the bottles were simpler and more tailored to a particular type of plastic than the microbes found in the plastics that were fed directly to the worms. When microbial communities are simpler and target a specific type of plastic, this translates to the potential for plastic to degrade. More efficiently when used in real life applications.

“Our study represents the first reported successful attempt to develop plastic-associated bacterial communities from the gut microbes of plastic-feeding worms,” said study first author Dr. Liu Yinan, a research fellow at CEE. “By exposing gut microbes to specific conditions we were able to enhance their abundance.” "Plastic-degrading bacteria found in our artificial worm gut, suggesting that our method is stable and widely reproducible."

The scientists say their proof of concept lays the foundation for developing biotechnological approaches that use worms' intestinal microbes to process plastic waste.

In their next steps, the scientists want to understand how bacteria in the beetle's gut break down plastics at the molecular level. Understanding this mechanism will help scientists engineer plastic-causing bacterial communities to break down plastic efficiently in the future.