Enzymes To Eat Plastic Waste
Pacific Ocean Plastic Pollution (credit: YouTube)
Plastic pollution is one of the largest environmental problems on land and in the oceans. Its impact on wildlife and birds is tragic when a giant whale died and washed up in Spain with 64 pounds of plastic in its stomach. Plastic can become 'atomized' into microscopic particles with the potential to become endocrine disruptors when they enter the ocean food chain when eaten by fish. Attempts to control the spread of discarded plastic has led to various innovative projects including Fishing 4 Plastic and the 5-Gyers project but these are still small compared to the problem's extent. A discovery has been made by laboratories that holds real promise for a biological and sustainable solution if it can be scaled-up to commercially viable levels.
British investigators at the University of Portsmouth and the National Renewable Energy Laboratory (NREL) in Colorado discovered a natural bacterial containing an enzyme that can "eats" the plastic-making chemical polyethylene terephthalate (PET). Made from petrochemicals, millions of tons in plastic bottles and other products are made globally with PET. It is estimated that a tiny fraction of these plastics, maybe 10%, are recycled with the bulk discarded.
Enzymes are natural catalysts that accelerate the rate of a chemical reactions. They catalyze biological processes in cells and are widely used in industrial processes. Virtually all enzymes are proteins which can be manipulated using the tools of modern molecular biology and biochemistry. The Portsmouth researchers identified the new catalyst while examining the structure of a bacterial enzyme that may have evolved in a waste recycling center in Japan. The bacteria could use the plastic as its food source. The labs characterized the protein, manipulated its biochemical structure to improve its catalytic rate and efficiency, and the bacteria degraded the plastic into its building blocks of carbon, hydrogen, and oxygen. The researchers speak about their discovery here:
Work remains for the enzyme to be used at a commercial scale but the need for environmental clean-up and restoration is vast. This complete research, Characterization and engineering of a plastic-degrading aromatic polyesterase, was published in the Proceedings of the National Academy of Sciences and is available: here
WHB