URochester biologist Anne S. Meyer and her colleagues created ‘bio-stickers’ that speed up plastic breakdown in marine environments.
DESIGNED TO DISAPPEAR: The Nereid Biomaterials team, including URochester biologist Anne S. Meyer, developed the first ocean instrument with 3D-printed bioplastic components. Intended for large-scale ocean carbon monitoring, the instruments are designed to biodegrade in marine environments instead of adding to plastic waste. Image credit: Melissa Omand, University of Rhode Island
Plastic waste poses an urgent problem for our planet’s ecosystems, especially our waterways. Millions of tons of plastic waste enter Earth’s oceans every year, and plastic has been found in every part of the ocean, including at the bottom of the deepest ocean trenches.
Although some biodegradable plastics, or bioplastics, have recently been developed, these plastics were intended to break down in industrial compost facilities. In cold, dark ocean environments, they break down very slowly.
What if there were a way to avoid the problem of plastic pollution while still reaping the benefits of plastic’s durability, versatility, and low cost?
To help tackle this problem, Anne S. Meyer, an associate professor in the University of Rochester’s Department of Biology and her colleagues developed a reusable 3D-printed “bio-sticker” that uses bacteria to break down bioplastic. The sticker, described in a paper in ACS Applied Polymer Materials, offers a controllable way to speed up plastic disintegration in environments where the plastic would otherwise linger for decades.
“This is a proof-of-concept that we could use living, engineered materials to help get rid of plastic in marine environments, making bioplastics more practical and environmentally friendly,” Meyer says.
The project is part of a larger collaboration with marine microbiologist Alyson Santoro at the University of California, Santa Barbara; University of Rhode Island oceanographer Melissa Omand; ecologist Ryan Freedman from the Channel Islands National Marine Sanctuary; and industry partner Mango Materials.
Supported by a $5 million National Science Foundation grant as part of the NSF’s Convergence Accelerator program, the group is testing the biodegradable bioplastic and developing solutions to accelerate breakdown.
Meyer, Santoro, and Omand additionally founded a start-up company called Nereid Biomaterials, which aims to make the ocean-degradable plastics available for various marine applications.
Rethinking ocean instruments
Ocean-degradable plastics will be vital for oceanographers, who are increasingly reliant on expendable, plastic instruments to observe and predict ocean phenomena. These instruments are often deployed in the ocean and never retrieved, adding to the growing amount of plastic in the sea.
“While these expendable ocean sensors are revolutionizing ocean research, they inherently pose a threat to the same environments that they are studying,” Meyer says. “We need new materials that can allow oceanographers to monitor the oceans without creating plastic ocean waste that gets left behind.”
The team has partnered with a handful of oceanographic equipment manufacturers who have committed to replace all, or a large portion of, their traditional petro-chemical plastic parts with the team’s ocean-degradable materials.
“This will introduce new sustainability into the fields of ocean observation, reef restoration, and maritime defense,” Meyer says.
Nature-inspired plastics
To create their ocean-degradable plastic, the team drew upon processes already found in nature. Their materials are based on a biopolymer called polyhydroxybutyrate (PHB)—a polyester naturally made by bacteria. Because bacteria have been making this polymer for billions of years, other marine microbes have naturally evolved to break down PHB.
At UC Santa Barbara, Santoro and her lab partners culture new bacteria that can break down PHB. One focus of their work is to isolate bacteria that thrive in the cold conditions of the ocean.
“We found that there’s a huge need for biodegradable materials and there is a range of lifespans that users required for their items,” she adds. The team spoke with regulators and nonprofits that deal with marine debris and found that some groups wanted a material that could disappear in a day, others wanted devices that would last a year, and yet others wanted to be able to trigger the degradation.
Bio-stickers that degrade plastic
This is where Meyer’s lab comes in. Meyer and the members of her lab have developed first-of-their-kind bacterial 3D printers. This revolutionary 3D-bioprinting approach allows them to embed PHB-degrading bacteria into engineered living materials.
The resulting “bio-stickers” are made with salt-tolerant bacteria suspended in a gel-like material. Users can place the stickers directly onto PHB-based bioplastics, where the bacteria remain alive and active for at least three weeks and speed up the material’s breakdown. The rate of degradation can be tuned by adjusting factors such as bacterial concentration or temperature. The stickers are also reusable, allowing them to be moved from one piece of plastic to another, and are stable and adhesive enough to be used in marine environments.
From prototype to ocean deployment
The team developed the bioplastics with input from industry partners and built a prototype with support from Omand at the University of Rhode Island, whose expertise in oceanographic sensor design helped shape the technology.
In collaboration with more than a dozen industry and government partners that committed to using the technology or supported the project in other ways, the researchers also tested how the bioplastics performed under different ocean conditions as well as how the material breaks down in marine environments.
The work could pave the way for engineered living materials that help create more sustainable, environmentally friendly alternatives to traditional plastics.
“After introducing our ocean-degradable bioplastic to ocean instruments, we plan to expand to other applications as well,” Meyer says. “Our tough plastics that break down in the ocean could be a great fit for aquaculture and fishing industries, ecosystem restoration efforts, maritime defense, or government agencies, such as the NOAA (National Oceanic and Atmospheric Administration) National Data Buoy Center.”
Source: University of Rochester
