According to the United Nations Development Programme (UNDP), the global plastic recycling rate is only 9%. The domestic plastic recycling rate is 16.8%, which is higher than the global average; however, most of the waste is disposed of in landfills. Yet, plastic waste discarded underground remains intact for hundreds of years, causing serious environmental pollution.
A research team led by Ryu Chung-min, the head of the Infectious Disease Research Center at the Korea Bioinformation Center, said on the 25th that they found a way to mass-cultivate enzymes that can break down plastic from the intestines of the honeybee moth.
The scientific community is researching biodegradable plastics to solve the problem of plastic waste. Biodegradable plastics are technologies designed to quickly decompose once buried underground while maintaining the durability and strength of conventional plastics. However, challenges remain in preserving the properties compared to existing plastics, and the expense is also higher.
The research team at the Korea Bioinformation Center discovered a method to quickly decompose regular plastic, not just biodegradable plastic, by finding an enzyme that oxidizes plastic from a type of moth known as the honeybee moth. The 'biological plastic degradation' technology, which uses enzymes from living organisms, is gaining attention as it is eco-friendly and can be used for managing existing plastic waste.
The honeybee moth feeds on wax, which is a primary component of beehives. Wax has a similar structure to plastic, making it a focus for implementing biological plastic degradation. The research team first revealed in 2019 that the enzyme cytochrome P450 secreted by the honeybee moth has the ability to digest polyethylene, one type of plastic.
Ryu noted, "While moths can break down plastic, the period during which they can consume plastic for decomposition is limited to just two weeks throughout their lifespan, making this method difficult for commercialization," and added, "We have found a way to mass-cultivate the moth's enzymes and apply them directly to plastic."
The research team successfully mass-cultivated plastic-decomposing enzymes by inserting the cytochrome P450 gene into yeast and cultivating it with insect cells. The enzymes produced by the cells were confirmed to effectively decompose plastic, even outside of the moth's abdomen.
Additionally, they succeeded in finding the principles of plastic decomposition of cytochrome P450 through simulations using artificial intelligence (AI) and increasing decomposition efficiency through genetic modification.
Ryu emphasized the significance of opening new possibilities for plastic waste treatment using insect-derived enzymes and stated, "We have precisely identified the operating principles of the plastic-decomposing enzymes and confirmed the practical application possibilities for waste plastic treatment for the first time."
The research findings were introduced in the Journal of Hazardous Materials on Oct. 23.
Reference materials
Journal of Hazardous Materials (2024), DOI: https://doi.org/10.1016/j.jhazmat.2024.136264