Training Bugs to Eat Plastic

Oct. 12, 2006
Worldwide, more than 14 million metric tons of polystyrene are produced annually. But the material is tough to dispose of because it takes thousands of years to decompose.

Julie Kalista
Online Editor

70% of polystyrene ends up in landfills within a year of manufacture and 99% of all polystyrene ultimately ends up in dumps. The long-term problem created by this versatile plastic is cause for major concern for local and national governments across the globe.

A solution could be near in the form of a new technology that combines chemistry and microbiology to help transform polystyrene into a useful biodegradable plastic. Dr. Kevin O'Connor, a lecturer in the University College Dublin School of Biomolecular and Biomedical Science and his research team have joined with Professor Walter Kaminsky of the University of Hamburg to work on a solution to the global growth of the styrofoam mountain.

Professor Kaminsky uses a technique called Pyrolysis that uses heat in a vacuum to break down the plastic into a crude pyrolysis oil, composed of 83% styrene. Dr. O'Connor feeds this oil to a bacterium (pseudomonas putida CA-3). These tiny microbes then transform it into a biodegradable heat-resistant plastic that can be used in a variety of forms ranging from plastic bottles to surgical parts.

As always with any recycling project there are concerns over energy-cost and by-products. Professor Kamisky believes that redistilling the crude pyrolysis oil could leave a cleaner styrene oil that could be consumed by the bacteria. The remaining crud could be burned, producing energy for the process.

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