The researchers added a stain to microplastic beads to observe the microbes that formed on their surfaces after incubation in Virginia’s York River. (Kelly Uhrig)
Research published in journals in 2025 FEMS Microbiology Ecology found that certain microorganisms that colonize microplastics not only degrade the plastic, but also have the potential to remove nitrogen from Chesapeake Bay waters.
“If we can figure out the bacteria, grow the bacteria, manipulate the bacteria… so that they can actually eat plastic effectively and break it down naturally, we’re hopeful that this will be a much better way to address the plastic problem in the environment,” said lead study author Samatha Fortin, a former Virginia Institute of Marine Science (VIMS) graduate student. “But that’s probably still a long way off.”
Plastic pollution is a huge problem around the world, and the Gulf region is no exception. For example, 83 percent of the trash found on beaches near the Virginia Aquarium and Marine Science Center from 2014 to 2018 was some type of plastic, according to the Virginia Marine Debris Reduction Plan. Plastics don’t necessarily decompose, but they do break up into tiny pieces known as microplastics, which can carry harmful chemicals and pathogens.
But there’s more to microplastic surfaces than that. Welcome to “Plastisphere”” No, we’re not talking about a science fiction movie. Plastisphere refers to the microbial community that forms on plastic waste. Fortin wanted to know what those microbes do.
Study co-author Kelly Uhlig, formerly of VIMS, started by placing three types of plastic beads in a mesh bag. She then dumped nine sets of each plastic into Virginia’s York River. She collected the plastic bags after 7, 14, and 28 days. After a week, microorganisms began to appear. Fortin then used metagenomic sequencing to study the DNA of various microorganisms.
Researcher Kelly Uhrig holds a rope of fiberglass mesh bags filled with different types of microplastics on the banks of the York River in Virginia. (Photo provided)
By looking closely at the endlessly repeated coding DNA sequences, Fortin discovered that the microorganisms on polyethylene plastics (such as plastic bags) have the most plastic-degrading genes.
She also discovered that microorganisms on polyvinyl chloride plastics (such as PVC pipes) have the most complete set of genes for denitrification. Microorganisms can convert bioavailable nitrogen into nitrogen gas and remove forms of nitrogen that excessively deplete water of oxygen.
But while it’s possible that microbes are accomplishing feats of defeating these contaminants, that doesn’t mean they’re actually doing so.. Further research will be needed to confirm whether bacteria actively utilize these genes.
Chris Burbage, an environmental scientist with the Hampton Roads Sanitary District, said these bacteria are very difficult to scale up for use in water treatment plants. The district funded this project, as well as other projects by Fortin, who helped identify microplastics in wastewater treatment systems.
“We’re not going to solve the problem of plastic pollution in marine debris with these particular (microorganisms) by themselves,” Burbage said. “I think the amount of plastic pollution is too high.”
2016 study published in the journal science They showed that bacteria with these genes can break down plastic, but it took more than a month in a lab environment.
VIMS marine science professor Bongkeun Song said this recent study is just the beginning. Lead author Fortin is now a postdoctoral fellow at Princeton University, while Song is studying whether microorganisms can deliver on the promise of genes.
