A groundbreaking study has unveiled the successful genetic modification of marine microbes to tackle plastic pollution in saltwater environments. This innovative approach focuses on the degradation of polyethylene terephthalate (PET), a plastic commonly found in products ranging from water bottles to clothing, and a significant contributor to microplastic pollution in our oceans. Nathan Crook, corresponding author of the research and an assistant professor of chemical and biomolecular engineering at North Carolina State University, expresses the significance of this development, stating, “This is exciting because we need to address plastic pollution in marine environments.”
Traditional methods of plastic removal, such as extraction and disposal in landfills, come with their own set of challenges. A more sustainable alternative lies in breaking down these plastics into reusable products. Crook adds, “It would be better if we could break these plastics down into products that can be re-used. For that to work, you need an inexpensive way to break the plastic down. Our work here is a big step in that direction.”
To tackle this challenge, the research team employed two species of bacteria: Vibrio natriegens and Ideonella sakaiensis. The former thrives in saltwater and is known for its rapid reproduction rate. The latter possesses the unique capability to produce enzymes that facilitate the breakdown of PET plastic.
The researchers extracted the DNA responsible for producing these enzymes from I. sakaiensis and incorporated it into a plasmid—a genetic sequence that can self-replicate within a cell, independently of the cell’s native chromosome. This plasmid was then introduced into V. natriegens bacteria, prompting them to produce the desired enzymes on their cell surfaces. Subsequently, the team demonstrated that V. natriegens could effectively break down PET plastic in a saltwater environment at room temperature.
Nathan Crook emphasises the scientific and practical significance of this achievement. He notes, “This is scientifically exciting because this is the first time anyone has reported successfully getting V. natriegens to express foreign enzymes on the surface of its cells.” Tianyu Li, the paper’s first author and a Ph.D. student at NC State, adds, “From a practical standpoint, this is also the first genetically engineered organism that we know of that is capable of breaking down PET microplastics in saltwater.”
Despite this groundbreaking advancement, three significant challenges remain. First, the researchers aim to integrate the DNA from I. sakaiensis directly into the V. natriegens genome to stabilize the production of plastic-degrading enzymes. Second, they plan to further modify V. natriegens to enable it to consume the byproducts produced during PET breakdown. Finally, the team intends to modify V. natriegens to produce valuable end products from PET, potentially serving as feedstock for the chemical industry.
Crook also expresses openness to collaborating with industry groups to determine which molecules would be most valuable for V. natriegens to produce, given its capacity for large-scale production. This promising research offers hope for a more sustainable future in the battle against plastic pollution in our oceans.