A study published in 2025 in the journal FEMS Microbiology Ecology found that certain microbes that colonize microplastics have the potential to not only break down plastic but also remove nitrogen from the Chesapeake Bay’s waters.
“If we can figure out bacteria and grow bacteria and engineer them to … actually effectively eat plastic and break it down naturally, then that’s going to hopefully be a much better way to deal with the plastic problem in the environment,” said Samatha Fortin, lead study author and former Virginia Institute of Marine Science (VIMS) graduate student. “But that’s likely still a long way away.”
Plastic pollution is an enormous problem around the world, and the Bay region is no exception. According to the Virginia Marine Debris Reduction Plan, for instance, 83% of the debris found on beaches near the Virginia Aquarium & Marine Science Center from 2014 to 2018 was plastic of one kind or another. Plastics don’t necessarily degrade but break into smaller pieces known as microplastics, which can carry hazardous chemicals and pathogens.
But there’s more to the surface of microplastics. Welcome to the “plastisphere.” And no, that’s not from a science fiction film. The plastisphere refers to the microbial communities that form on plastic waste. Fortin wanted to find out what those microbes could do.
Kelley Uhlig, a study co-author also formerly at VIMS, started by placing three kinds of plastic beads into mesh bags. Then, she put nine sets of each plastic into the York River in Virginia. She retrieved a bag of each plastic after 7, 14 and 28 days. The microbes started to appear after a week. Fortin then used metagenomic sequencing to study the DNA of the different microbes.
After coding and poring over the endlessly repeating DNA sequences, Fortin found that microbes on polyethylene plastic (such as plastic bags) had the most plastic-degrading genes.
She also found that microbes on polyvinyl chloride plastic (PVC pipe, for example) had the most complete sets of genes for denitrification. The microbes could potentially convert biologically available nitrogen into nitrogen gas, removing the form of nitrogen that, in excess, depletes the water of oxygen.
But while the microbes can potentially be achieving these pollution-punching feats, it doesn’t mean they are doing so. It would take more research to confirm whether the bacteria are actively using those genes.
Chris Burbage, environmental scientist with the Hampton Roads Sanitation District, said it would be extremely difficult to scale up these bacteria for use in a water treatment plant. The district funded this project and others by Fortin as she helped the utility identify microplastics in wastewater treatment systems.
“We’re not going to solve our marine debris plastic pollution problem with these specific [microbes] themselves,” Burbage said. “I just think the volume of plastic pollution is too great.”
A 2016 study published in the journal Science showed that bacteria with these genes can break down plastic, but it took over a month in lab conditions.
VIMS marine science professor Bongkeun Song said this recent study is just the beginning. While lead author Fortin is now a postdoctoral researcher at Princeton University, Song is working to learn whether the microbes can achieve what their genes promise.
Us. It can eat us too. Good job everyone.
What are the effects on animals ingesting bacteria engineered to eat plastics?