An environmental issue that grabs the attention of governments and environmentalists around the world is the careless disposal of plastic garbage. Waste generation rates are increasing globally, with much of it classified as single-use plastic goods.
World Bank estimates that the world produced around 2.24 billion tonnes of solid garbage in 2020. And the annual global waste generation is anticipated to rise by 73% in 2050, reaching up to 3.88 billion tonnes. While plastic pollution is already pretty widespread, the situation is only getting worse as a result of human consumption and population expansion. It has degraded the quality of land, air, and water, posing serious risks to the environment. Because they are made of a wide variety of harmful substances, plastics have serious negative impacts on the entire planet.
One of the most prevalent types of plastic is polystyrene. A large percentage of it is disposed of in landfills and oceans, endangering aquatic wildlife. Plastics are difficult to recycle, and recycled plastic loses quality, which drastically lowers its value and performance. Out of the total global plastic waste, only 9% gets recycled while 22% is mismanaged. Meanwhile, other forms of plastic like styrofoam (polystyrene) have even more troubling metrics. Around 84% of the 3 million tonnes of expanded polystyrene (EPS), solid beads of polystyrene, produced annually in the U.S, end up in landfills. In 2018, the recycling of styrofoam containers produced in the United States was less than 5,000 tonnes of the 80,000 tonnes.
Researchers at the University of Queensland have recently discovered that Zophobas morio, a kind of worm with a polystyrene hunger, could be one of the solutions to global plastic recycling. These small but ravenous superworms may prove to be beneficial for removing styrofoam waste from landfills, thanks to their bacterial enzymes and extraordinary capacity to consume polystyrene.
For three weeks, Dr. Chris Rinke and his team from the University of Queensland's School of Chemistry and Molecular Biosciences monitored the diet of the superworms. Some were fed with polystyrene foam, some with bran, and some fasted. They observed that the superworms that consumed solely polystyrene not only thrived but also showed weight gain. An indication of polystyrene being a source of energy for the worms. The team used genetic analysis called metagenomics to examine their gut which revealed the presence of several encoded enzymes with the potential to break down polystyrene and styrene.
“Superworms are like mini recycling plants, shredding the polystyrene with their mouths and then feeding it to the bacteria in their gut,” said Dr. Chris Rinke. “The breakdown products from this reaction can then be used by other microbes to create high-value compounds such as bioplastics.”
The focus of the research is to engineer enzymes that can help increase the recycling of plastic trash and decrease landfill waste. If the research proves to be fruitful, what we can expect in the future is mixing ground Styrofoam materials with superworm enzyme liquid solution to break down plastic and clean up our precious resources.
The research article is published in Microbial Genomics, Volume 8, Issue 6, titled “Insights into plastic biodegradation: community composition and functional capabilities of the superworm (Zophobas morio) microbiome in styrofoam feeding trials.”