New marine bacteria: a promising solution against plastic pollution!

Mangroves, these tropical coastal forests, have long been recognized for their ecological importance. Today, they reveal a new asset in the fight against pollution. Diego Javier Jiménez Avellaa researcher at MEGBLab at KAUST University, points out: “Mangrove ecosystems are exposed to high levels of plastic and their soils contain diverse microbial communities, including plastic-active microorganisms.”

This discovery is part of an alarming context of the proliferation of plastic in the oceans. Researchers have developed an innovative technique to select bacteria capable of transforming plastic, in particular polyethylene terephthalate (PET). This approach could revolutionize strategies to combat plastic waste on a global scale.

The study highlighted the impact of PET particles and seawater intrusion on the mangrove soil microbiome. An enrichment culture made it possible to select a group of PET-transforming microbes, paving the way for promising applications.

Mangrovimarina plasticivorans: a revolutionary bacteria

Genomic analysis of bacterial consortia revealed a major discovery: the identification of a new bacterial genus baptized Mangrovimarina plasticivorans. This microorganism is distinguished by its ability to decompose and transform PET using specific enzymes.

Two essential genes have been identified in this bacteria:

• A gene encoding monohydroxyethyl terephthalate hydrolases
• A second gene capable of degrading a PET by-product

This discovery marks a significant advance in our understanding of the natural transformation of PET. For the first time, researchers have demonstrated that a bacterial consortium from mangrove soils can transform a hydrolyzable plastic made from fossil fuels.

From laboratory to industrial application: challenges and perspectives

Alexandre S. Rosadosenior researcher at KAUST and head of the MEGBLab, tempers the enthusiasm: “These laboratory-scale findings are a step towards tackling plastic pollution and require further research and development – ​​such as optimization and implementation at scale – before they can be applied practically.”

The team's approach nevertheless opens up promising perspectives:

1. Design of microbial inoculants to accelerate PET degradation
2. Development of specific enzymatic cocktails
3. Potential application to various terrestrial and aquatic ecosystems
4. Identification of new plastic-degrading microbes or enzymes

This international collaboration, initiated in 2021, involves eight institutions spread across seven countries. The goal is to design efficient microbial consortia for plastic processing, both in the laboratory and in large-scale industrial settings.

Investigations continue, particularly on the mangroves of the Red Sea, to refine our understanding of these biological processes and explore their potential for large-scale application. This discovery opens a new path in the fight against plastic pollution, combining scientific ingenuity and natural solutions inspired by mangrove ecosystems.