Bioengineering, Biomimicry Spawn Novel Solutions to Marine Plastic Pollution

Ingenuity from UK and US universities has led to the development of next-generation solutions to eliminating plastic waste — particularly, in tricky marine environments.

Published 1 week ago | About a 5 minute read

Image: Naja Bertolt Jensen

As we well know, plastic has become one of the world’s most prolific polluters. According to the OECD, 22 million tonnes of plastic waste leaked into the environment in 2019 — a number projected to double by 2060 — and roughly 20 million metric tons of that ends up in the world’s waterways every year.

New strategies for tackling the issue continue to emerge from innovators large and small; and until an enforceable plastics treaty is in place and brands and plastic producers turn their commitments into action, academic researchers continue to concoct potential solutions.

Scottish startup creates ‘smart’ plastic that self-destructs in water

Image credit: E.V.A Biosystems

University of Edinburgh startup E.V.A Biosystems has developed a plastic that can sense when it’s in the ocean and break itself down without creating microplastics.

E.V.A’s solution adds special bacteria to conventional plastic that can detect when they’re in aquatic environments and activate enzymes that break down the material. And unlike when plastics slowly degrade in landfills or aquatic environments, or even during most recycling processes, E.V.A said the process does not create harmful microplastics.

“We’re all struggling with plastic pollution; and while there are many people developing biodegradable plastics, they’re too expensive and only make up about 1 percent of the world’s plastic,” said E.V.A founder Dr Alexander Speakman, who received his PhD in Bioengineering at the University of Edinburgh. “Our technology works with existing plastics, making them ‘smart’ enough to break down when they end up where they shouldn’t be, like in our oceans or landfills.”

The new solution won top prize in the Net Zero category at this year’s Converge Awards — which highlight new Scottish academic innovations each year. E.V.A. earned a £30,000 cash prize, as well as £19,500 of in-kind business-development support from Scottish energy company SSE (which sponsored the award) and Converge’s network of industry partners. The company also took home the £20,000 IBioIC Award — presented to a biotech business with a product or process that addresses a real market need.

Rice researchers develop sticky, biomimetic solution to marine plastic pollution

Image credit: Georg Eiermann

Meanwhile, in the US, scientists at Texas’ Rice University have been inspired by nature’s adhesive genius — in this case, the sticky power of mussels — to create bioengineered microorganisms with powerful cling capability that could transform environmental cleanup. By combining this amplified adhesive power with an enzyme that breaks down harmful plastics, their discovery offers a potential new tool for tackling plastic pollution — especially, in marine environments.

According to the research, published in the journal, Small Methods, the innovation could also curb biofouling — the accumulation of microorganisms, plants, algae and small animals on submerged surfaces that can damage ships’ hulls, underwater structures and pipes — addressing long-standing challenges in industries ranging from shipping to medicine.

PET, a popular plastic for packaging that makes up the majority of global plastic pollution, is notoriously resistant to degradation — taking centuries to decompose. The Rice team’s innovation allowed it to create adhesive bacteria and proteins that could help countries worldwide more efficiently decompose PET.

“Very excitingly, our research holds promise for addressing the growing problem of plastic pollution in the US and across the globe,” said study leader Han Xiao — director of Rice’s Synthesis X Center; an associate professor of chemistry, biosciences and bioengineering; and a Cancer Prevention and Research Institute of Texas (CPRIT) scholar.

Tackling plastic pollution

The engineered bacteria were designed using genetic code expansion technology — incorporating a natural amino acid called 3,4-dihydroxyphenylalanine (DOPA), responsible for mussels’ adhesive properties — which significantly enhanced their ability to bind to PET surfaces.

The altered bacteria, tested on PET samples at 37°C, demonstrated a 400-fold increase in adhesion. The bacteria was then united with an enzyme called polyethylene terephthalate hydrolase to break the material into smaller, more manageable fragments — resulting in what the researchers call a significant amount of degradation of the plastics overnight.

This approach could provide a novel solution to plastic recycling, offering a faster and more efficient way to reduce plastic waste and its environmental impact.

“Our approach underscores the innovative utility of genetic code expansion in material and cellular engineering,” Xiao said. “It can potentially transform bioengineering applications and solve real-world problems.”

Other applications

In addition to addressing plastic pollution, the DOPA-modified proteins showed strong bonding capabilities to organic and metallic surfaces — creating a barrier that prevents the accumulation of microorganisms and other materials, which could be a game-changer in fighting biofouling.

The researchers’ discovery has even broader applications, including in the healthcare field. For example, it can be used to prevent bacterial growth on medical devices, making them safer and more effective.

“This will open up new avenues for leveraging these interactions to develop smart material-protein conjugates for various biomedical applications like implantable medical devices, tissue engineering and drug delivery,” said Mengxi Zhang, first author of the study and a graduate student in chemistry.

Adhesion in wet environments is an ongoing business challenge, and the Rice team isn’t the first to be inspired by mussels for potential solutions: A startup called Mussel Polymers — one of 10 winners of the Biomimicry Institute’s 2021 Ray of Hope Prize — developed a high-performance, non-toxic adhesive modeled on the proteins mussels use to adhere to surfaces in extreme marine environments, that is 300 percent stronger than other underwater adhesives. Mussel Polymers can also be used in a number of industries, but it was brought to market first for dental and biomedical applications and coral restoration.