Australian Scientists Discover Superworms That Digest Styrofoam, Offering Hope For Plastic Waste Management

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Plastic is a non-biodegradable material, meaning it cannot be decomposed naturally by bacteria and other microorganisms and thus stays in the environment for decades, impacting soil and water. They are more hazardous than degradable wastes like paper, food waste, sewage and cow dung that can be decomposed easily and utilised as organic material for soil (composting).

Image Credit: Microbial Genomics Journal

However, after a recent discovery by scientists from the University of Queensland in Australia, plastic may come under the category of degradable waste material, and yes, it is true.

Scientists have found a way to recycle plastic with a technique already present in nature. They have discovered beetle larvae with the capability to digest styrofoam, a type of trademarked polystyrene foam. The study is published in the journal Microbial Genomics. [1]

Here are the details.

About Superworms That Digest Styrofoam

Superworm is the common name for the larvae of Zophobas morio that fall into a species of darkling beetle. The larvae are about 50-60 mm long when they reach their full size and have a dark body colour at both ends. With time, their body colour gets fully black and they pupate as darkling beetles when kept alone for around 7-10 days.

For the research, the scientists used larvae of superworms and found out about a specific gut enzyme that helps digest plastic.

The research team fed three groups of superworms various diets over the course of three weeks. The diets consisted solely of polystyrene, wheat bran and fasting diets (no food). The superworms in the fasting group were separated from one another to prevent cannibalism, as no food was fed to them. Also, all the groups were watched for any indications of cannibalism.

Over the course of three weeks, the worms fed bran significantly improved in health and doubled their weight compared to the other groups.

The scientists then kept an eye on whether these larvae would develop into beetles. Nine out of ten individuals in the bran-diet group developed into beetles and had the most functional gut microbiome compared to the other two groups.

The noticeable thing was that two-thirds of the plastic-eating superworms have also evolved into beetles. This is because plastic seems to be a poor diet for larvae, but instead, the worms were not only able to survive, but efficiently gained weight, digested plastic and got the energy to convert themselves into beetles.

Around 93 per cent of the bran-fed larvae turned into beetles, 66.7 per cent of the polystyrene larvae and 10 per cent of the starved ones.

Why Is This Discovery The New Hope For Plastic Waste Management?

The discovery could be the new hope for plastic waste management as it could help researchers identify the enzyme or microbes in the digestive system of the superworm that can break down polystyrene and lower the burden of plastic waste in the environment.

However, researchers were less interested in the microbes present in the guts of larvae than in the enzymes that have been produced to digest plastic. That is why, they have isolated the gene from the guts of the larvae to decode the enzymes involved in digesting polystyrene.

What's The Next Step?

According to the researchers of the study, their next step is to find those enzymes that can someday, help in recycling or making fresh bioplastics, for a clean and plastic-free environment.