Scientists at Australia's University of Queensland found that the superworm, the larva of the German beetle (Zophobas morio), is particularly fond of eating polystyrene, one of the most common forms of plastic used for packaging and disposable tableware.
The results of the study show that their intestinal enzymes give rise to hope for the development of more sophisticated plastic recycling technologies. Research leader Chris Rinke said previous reports had shown that small waxworms and mealworms have a good track record of eating plastic.
Researchers have found that these superworms can survive only on a diet of polystyrene, which is used in a variety of products, from cups to packaged nuts.
"The worm's ability to process plastic shows that plastic is very efficiently broken down in the creature's digestive tract. They are basically like eating machines," Rinke said as quoted by Scientific American.
In their study, researchers divided the 135 creatures into three groups. The first group was given only wheat bran, the second was fed only soft polystyrene, and the third was given nothing.
All worms were monitored for cannibalistic activity and group members who were not fed anything were isolated from each other. As a result, the larvae fed the bran were significantly healthier than their plastic-fed or non-fed counterparts.
They more than doubled their body weight over the three weeks that followed. After that, several worms from each group were set aside to grow into beetles.
Nine out of 10 worms fed bran managed to grow into beetles and maintain the most diverse gut microbiome of the three groups. While the larvae that were fed plastic, the growth was less encouraging. But they are still heavier than starving worms, and two-thirds of them grow into beetles.
"It is clear that polystyrene is a poor food for larvae. But it appears they can extract at least some energy from the plastic material," Rinke said.
He and his colleagues don't suggest superworms being simply released into landfills to chew up piles of plastic. The point of this research is to discover that the unique intestinal microbiome of the worms may hold the key to developing the chemical processes to break down the material.
The researchers plan to use the study's data as a basis for experimentally verifying what each identified bacterial enzyme does to plastics and how these enzymes are the most efficient way to break down plastic waste in the world.