A ‘superworm’ with an appetite for polystyrene could be the key to plastic recycling on a mass scale, according to a new study. The species is capable of munching through plastic waste thanks to a bacterial enzyme in their gut, say Australian scientists.
Dr Chris Rinke, and his team at the University of Queensland’s School of Chemistry and Molecular Biosciences, fed superworms different diets over a three-week period, with some given polystyrene foam, some bran, and others put on a fasting diet.
They discovered that the common Zophobas morio ‘superworm’ can eat through polystyrene.
“We found the superworms fed a diet of just polystyrene not only survived, but even had marginal weight gains,” Dr Riske said. “This suggests the worms can derive energy from the polystyrene, most likely with the help of their gut microbes.”
The research team used a technique called metagenomics to find several encoded enzymes with the ability to degrade polystyrene and styrene.
Dr Riske says the long-term goal is to engineer enzymes to degrade plastic waste in recycling plants through mechanical shredding, followed by enzymatic biodegradation.
“Superworms are like mini recycling plants, shredding the polystyrene with their mouths and then feeding it to the bacteria in their gut,” he said.
“The breakdown products from this reaction can then be used by other microbes to create high-value compounds such as bioplastics.”
The team hope that the ‘bio-upcycling’ will incentivise plastic waste recycling and reduce landfill.
Study co-author Jiarui Sun says they aim to grow the gut bacteria in the lab and further test its ability to degrade polystyrene.
“We can then look into how we can upscale this process to a level required for an entire recycling plant,” PhD candidate Ms Sun said.
Dr Rinke said there are many opportunities for the biodegradation of plastic waste. “Our team is very excited to push the science to make it happen,” he added.
The findings were published in the journal Microbial Genomics.