PORTLAND — Morgan Vague was speechless when she looked through the microscope.
For weeks the Reed College senior, who majored in biology, had been diligently checking her specimens hoping that she would see progress. On a Monday afternoon late last year, she saw it.
Three types of bacteria she had isolated and bred in the lab were beginning to consume one of the most ubiquitous pollutants out there, polyethylene terephthalate.
“I got really quiet,” Vague said of the day she made the discovery, “and then I squealed a little bit. And then I called my mom.”
Polyethylene terephthalates, commonly known as PET, is in a ton of consumer goods, from plastic bottles to clothes to food packaging. The material takes decades, if not longer, to degrade in the environment and is a significant contributor to pollution worldwide, especially in the ocean where some so-called “garbage patches” have reached gargantuan proportions.
That’s what led Vague to start researching ways to combat the scourge of PET pollution. A native of Houston, Texas, she collected samples of soil, sand and water from around Galveston Bay, near her hometown, which she knew were heavily polluted with petroleum. She was working off the theory that, in places with high levels of petroleum pollution, there were likely to be microbes that had evolved to consume it.
She snuck the samples back to Portland in her carry-on luggage and began isolating individual microbes to see if they produced lipase, a chemical that breaks down plastic into material that can be consumed by bacteria. Of the roughly 300 she had, 20 had the ability to produce the important material.
She picked the three with the highest lipase-producing potential and gave them polyethylene terephthalate as their only option to eat.
All three — Pseudomonas putida, Bacillus cereus and another unknown strain Vague is calling Pseudomonas morganensis, as she appears to be the first researcher to identify it — began feasting on the plastic. It was a novel discovery, especially for an undergraduate, said Jay Mellies, a biology professor at Reed and Vague’s supervisor on her thesis project.
“This is a watershed moment,” he said.
Mellies pointed out that the bacteria Vague isolated occurred naturally, so there’s no risk of them getting loose and consuming plastics they aren’t supposed to. He also noted that a lot of research still needed to be done before they could be deployed to start eating pollutants outside of a lab.
Over the summer, Vague said she’d be looking into ways to speed up the process and see if it could be scaled up to meet industrial needs, while also looking into graduate school applications. Still, her discovery marks a high point in her time at Reed.
“To go through this long, arduous process and then to see something novel,” she said, “it was so exciting.”
