Researchers Identify Plastic-Degrading Microbes in Mangrove Soil

With plastic pollution reaching alarming levels globally, even in remote ocean environments, ecosystems like mangroves—crucial biodiversity hotspots—are under threat from various stressors, including plastic contamination.

“Mangrove ecosystems are exposed to significant plastic pollution, and their soils harbor diverse microbial communities, including those with potential plastic-degrading capabilities,” explained Diego Javier Jiménez Avella, a research scientist from the Microbial EcoGenomics and Biotechnology Laboratory (MEGBLab) at KAUST, who led the study. “We hypothesized that these soils could be a valuable source of plastic-degrading microbes, although microbial diversity and metabolic activity in mangrove soils remain largely unstudied.”

The research revealed the presence of a novel bacterial genus, Mangrovimarina plasticivorans, which carries genes encoding enzymes known as monohydroxyethyl terephthalate hydrolases—capable of breaking down PET byproducts. This is the first time a bacterial consortium from mangrove soil has been shown to transform a fossil-fuel-based plastic like PET.

"Engineering microbiomes to effectively degrade plastics is a promising yet complex task," Jiménez said. "While we are excited about these findings, scaling the approach and applying it in natural environments pose significant challenges."

This innovative approach to microbial inoculation and enzyme cocktail design could be extended to a variety of ecosystems, potentially uncovering more novel plastic-degrading microbes or enzymes. The research team, which began their collaboration in 2021, includes experts from Colombia, Brazil, the U.S., Germany, Australia, the U.K., and Saudi Arabia. 

“These findings represent a significant step toward addressing plastic pollution, but further research and development—such as optimization and scalability—are needed before they can be practically applied on a large scale,” said Alexandre S. Rosado, the principal investigator at KAUST and leader of the MEGBLab.

The team continues to explore the plastic-degrading potential of microbial communities from Red Sea mangroves, with the goal of advancing these early laboratory results into effective solutions for real-world applications.