Packing peanuts, CD cases, disposable culture, and more are materials made from polystyrene, the most common form of plastic. Unfortunately, these products are not easy to recycle, with the vast majority stocking up in landfills or the world's oceans, threatening marine life.
Australia's Superworm: A Key to Recycling
University of Queensland, Australia, scientists have just discovered that a superworm - Zophos Morio darkling beetles' larvae- are more than eager to devour substances, with their gut microbiome holding enzymes that could be the key to increasing recycling rates.
Chris Rinke, the lead author of a recent study published in the journal Microbial Genomics, titled "Insights into plastic biodegradation: community composition and functional capabilities of the superworm (Zophobas morio) microbiome in styrofoam feeding trials Open Access," explains that previous reports suggest that tiny waxworms and mealworm - also beetle larva- have a good track record when it comes to the consumption of plastics. Hence they hypothesized that larger superwoms could consume even more plastic.
Superworms can grow up to two inches and are bred as a food source for different reptiles, birds, and even humans in countries like Thailand and Mexico.
Together with his team, Rinke fed these superworms various diets over three weeks. Some were given polystyrene foam - styrofoam, with some bran, and others were not fed. Rinke says that the team confirmed that these superworms can survive on the sole diet of polystyrene and even gain some weight - compared to the starved control group - suggesting that the worms can gain energy from eating plastics, reports ScienceAlert.
Despite the superworms reared on polystyrene completing their life cycle, graduating to fully developed adult beetles, succeeding tests showed a loss of microbial diversity in the superworms' guts and potential pathogens.
This result suggests that while the worms can survive solely on polystyrene, it isn't a nutritious diet and impacts their health.
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Microbial Gut of Superworms
After the initial experiments, researchers wanted to explore the mechanisms at play that allowed the worms to consume plastics fully. The team used metagenomic techniques to analyze the microbial gut community and find the gene-specific enzymes involved in the degradation of plastics.
One way the results could be used is to provide superworms with food waste and agricultural bioproducts to be consumed alongside plastics. Rinke explains that this could be a step in improving the worms' health and dealing with a large amount of food waste in Western countries.
However, although these worms can be bred for the sole purpose of recycling, Rinke envisages another route: creating recycling plants that mirror what the superworm larvae do, which is first to shred the plastics, digest, and then break down with enzymes. He explains that the researchers ultimately want to take the superworms out of the equation. He plans to continue researching superworms and find a more efficient way of extracting and replicating the enzyme while enhancing them further via enzyme engineering.
Previously, studies about wax worms have been able to pinpoint their saliva as a degrading agent for plastics.
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