PET is an environmental nightmare. The plastic is biologically inert, notoriously resilient, and takes years, even centuries, to break down. An estimated 480 billion plastic bottles are manufactured every year, and after they have served their purpose many of them wind up in landfills, rivers, and oceans‐the infamous Pacific trash vortex is currently the size of Texas.
But biologists at Reed have recruited an unlikely ally in the fight against plastic pollution‐bacteria. Certain strains of bacteria produce lipase, a fat-digesting enzyme that can break down plastic molecules and render them palatable‐in theory, anyway.
"The problem for most bacteria is that PET is a big, tough molecule with a lot of weird components," says Morgan, who performed the research for her senior thesis. "Lipase is kind of like marinade on a steak. The bacteria squirts out the lipase and the lipase breaks the plastic into bite-size pieces."
"These are very significant results," says Prof. Jay Mellies, who supervised Morgan’s research. "It points the way towards a biological means of degrading plastic pollution."
At the beginning of her quest, Morgan went hunting for microbes in locations with high levels of petroleum pollution, on the theory that those bacteria were most likely to have evolved biological mechanisms for digesting plastic. She traipsed around refineries in her hometown of Houston, Texas, digging up samples of soil, sand, and water around Galveston Bay. She snuck her samples into a refrigerated bag on her flight back to Portland, hoping that airport security screeners wouldn’t freak out. (They didn’t.)
Then she began the long, laborious process of screening her samples for lipase. Out of roughly 300 separate strains of bacteria, she identified 20 that produced the enzyme; three of these boasted high levels of lipase.
