Packaging material, disposable cutlery, CD cases: polystyrene is one of the most common forms of plastic, but recycling it is not easy and the vast majority ends up in landfills or ends up in the oceans where it threatens marine life.
Scientists from the Australian University of Queensland have just discovered that super worms, the larvae of Zophobas morio mealworms – are eager to eat stuff, and their gut enzymes might hold the key to a higher recycling rate.
Chris Rinke, who led a study published in the journal Microbial genomics Thursday, told AFP that previous reports had shown that tiny wax and mealworms (which are also beetle larvae) had a good history of plastic consumption, “so we issued the hypothesis that much larger superworms can eat even more”.
Superworms grow up to two inches (five centimeters) and are bred as a food source for reptiles and birds, or even humans in countries like Thailand and Mexico.
Rinke and his team fed supervers different diets over a three-week period, given polystyrene foam, commonly known as styrofoam, bran, and others not fed at all.
“We confirmed that superworms can survive on a single polystyrene diet, and even gain some weight – compared to a starvation control group – suggesting that worms may gain energy by eating polystyrene” , did he declare.
Although the supervers raised in polystyrene had completed their life cycle, becoming pupae and then fully grown adult beetles, testing revealed a loss of microbial diversity in their guts and potential pathogens.
These results suggest that although insects can survive on polystyrene, it is not a nutritious diet and impacts their health.
Next, the team used a technique called metagenomics to analyze the gut microbial community and find which gene-encoded enzymes were involved in plastic breakdown.
One way to use the results would be to supply superworms with food waste or agricultural bioproducts to consume along with polystyrene.
“This could be a way to improve worm health and deal with the large amount of food waste in Western countries,” Rinke said.
But if it’s possible to breed more worms for this purpose, he’s considering another route: creating recycling plants that mimic what the larvae do, which is to first shred the plastic in their mouth and then digest it using bacterial enzymes.
“Ultimately, we want to eliminate supervers from the equation,” he said, and he now plans more research aimed at finding the most effective enzymes and then further improving them through engineering. enzymatic.
The breakdown products of this reaction could then be passed on to other microbes to create high-value compounds, such as bioplastics, in what he hopes will become an economically viable “recycling” approach.
© Agence France-Presse