November 13, 2023
A fascinating article from The Guardian by environmental journalist Stephen Buranyi recently caught my attention in its discussion of contemporary research surrounding plastic-eating bacteria. Discovered in a trash dump in 2001, a bacterium called Ideonella Sakaiensis uses enzymatic reactions to break down plastic into basic nutrients it can consume. Microbiologists are studying this enzyme, PETase, and other similar enzymes to try to engineer the most efficient biological tool for degrading plastic through mutation experiments. The article also explains how bacteria are already being applied to the plastic recycling process: a French company called Carbios employs a bacterial enzyme to break PET waste down into precursor molecules, which can then be reused to make new plastics. While this process, which involves shredding and freezing the waste and then placing it inside a sealed steel tank with a solution of the enzyme, is not carbon-neutral nor as ideal as composting the plastic, it’s a step in the right direction; it produces about half the emissions as making new plastic does, and it allows for plastic to be recycled again and again (regular recycling lowers the material quality of plastic by snapping its fibers, so it can be repurposed only a limited number of times). Carbios currently processes 250kg of plastic waste daily and intends to raise that number to over 130 tons daily when its new facility opens in 2025. While microbes cannot yet transform plastic the way they do organic matter, researchers like Kohei Oda of the Kyoto Institute of Technology, whose team discovered the original plastic-eating bacteria, and Victor diLorenzo of the Spanish National Biotechnology Centre, remain optimistic about their potential. According to diLorenzo, this research could introduce “a new partnership between science and the natural world,” but public support is needed to make funding available for large-scale endeavors.
One of the points that excited me most from this article reports that a German group has been able to transform the PETase enzyme into a marine algae, which could eventually be used against ocean microplastics. I’ve been following news on microplastic research over the past year and a half and have grown accustomed to seeing many statements about the severity of the problem but few about truly effective solutions. Filtering out these tiny, sometimes microscopic, particles from our oceans seems an incredibly difficult and daunting task; if we figured out how to eliminate them on a large scale using algae, it could be revolutionary. This research will certainly require time and money, so I don’t expect to see an immediate breakthrough; however, I will continue to follow the story and am eager to see updates. This article emphasizes important connections between the fields of microbiology and environmental science, and as someone who is interested in both, I am delighted to see emerging research projects that combine them.
