Scientists from the Royal Botanic Gardens, Kew, and their collaborators have discovered a wide range of microorganisms, including fungi and bacteria, in the coastal salt marshes of Jiangsu, China, that have the ability to break down plastic.
Phys.org reported that the team identified 184 strains of fungi and 55 strains of bacteria that can degrade polycaprolactone (PCL), a type of biodegradable polyester commonly used in the production of various polyurethanes. They also found that certain bacterial strains belonging to the genera Jonesia and Streptomyces possess the potential to further break down other petroleum-based polymers, whether they occur naturally or are artificially produced chains of molecules.
Plastic-Eating Microorganisms Could Tackle Growing Global Waste
In the recent research, titled "The Distinct Plastisphere Microbiome in the Terrestrial-Marine Ecotone Is a Reservoir for Putative Degraders of Petroleum-Based Polymers" article published in the Journal of Hazardous Materials, researchers reported conducting a study in May 2021 at the UNESCO-protected area Dafeng near the Yellow Sea Coast in eastern China.
Researchers are increasingly turning to microorganisms to address the pressing issue of plastic pollution, which has seen a significant rise since the 1970s, with an estimated 400 million tons of plastic waste produced annually according to the United Nations Environment Program (UNEP). The concept of the plastisphere offers hope for finding solutions to this problem.
Earlier research has already acknowledged the potential of microorganisms in combating plastic waste. In a 2017 study, scientists from China and Pakistan discovered a strain of fungi called Aspergillus tubingensis that could break down plastic at a landfill in Islamabad, Pakistan. So far, 436 species of fungi and bacteria have been identified as capable of degrading plastic.
The researchers of the recent study collected 50 plastic waste samples from Dafeng, encompassing seven different types of petroleum-based polymers, including polyethylene terephthalate (PET), expanded polystyrene (EPS), polyethylene (PE), polyurethane (PU), polyamide (PA), polypropylene (PP), and polyvinyl chloride (PVC).
Among the samples, the scientists identified 14 genera of fungi, including Fusarium and Neocosmospora, which are known as plant pathogens. These fungi obtain their nutrients from plants but harm the host in the process.
The study suggests that these fungi might be more effective at degrading PCL plastics and synthetic polymers compared to saprotrophic fungi, which typically feed on deceased plant and animal matter.
Confirming the Presence of Microbiome in the Plastisphere
According to the Smithsonian Ocean, floating objects in the ocean can attract and accumulate various forms of life. Just like fishermen use floating buoys to concentrate fish, microscopic organisms, such as bacteria, algae, and other single-celled organisms, gather and colonize plastic and other floating objects in the water.
Even tiny fragments of plastic debris as small as a pinky nail can serve as hubs for microbial aggregation. This community of microbes forms a thin layer of life, known as a "plastisphere," on the surface of the plastic. The term "plastisphere" is analogous to the layer of life on Earth's surface called the "biosphere."
The new study aimed to examine microorganisms capable of breaking down plastic, specifically focusing on a terrestrial plastisphere. It confirmed the existence of a unique microbiome in the coastal plastic debris, which differed from the surrounding soil. Researchers highlight the significance of investigating the microbial communities within the plastic waste at Dafeng's salt marshes. The initial findings have been both exciting and promising, thanks to the unique ecological niche present in the area.
RELATED ARTICLE: A Plastic-Eating Bacteria Discovery for Plastic Pollution Crisis
Check out more news and information on Plastic Pollution in Science Times.
