American researchers have utilized a specific strain of bacteria to transform a significant component of disposable cups, plates, and kitchen utensils into a biodegradable plastic. This potential could greatly reduce the environmental impact of this common yet challenging-to-recycle waste.
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Polystyrene foam is used for boxes, plates, and food containers. |
The strain of bacteria in question is a special variant of Pseudomonas putida, which is found in soil. These bacteria have successfully converted polystyrene foam—known for its difficulty in decomposition and commonly used for food packaging—into a biodegradable plastic.
According to Dr. Kevin O’Connor, the lead researcher from Dublin University, this is the first study demonstrating the ability to transform petroleum-based plastic waste into a reusable, biodegradable form of plastic.
O’Connor and his colleagues from Ireland and Germany employed pyrolysis to convert polystyrene, a primary component of many single-use products, into styrene oil. They then provided this oil to P. putida, a bacterium capable of consuming styrene.
The result was that the bacteria converted the oil into a biodegradable plastic known as PHA (polyhydroxyalkanoates). O’Connor noted that this process could also be applied to other types of plastic waste to produce PHA.
PHA is widely used in medicine, kitchen utensils, packaging films, and disposable items. This biodegradable plastic is resistant to high-temperature liquids, oils, and fats, and has a relatively long shelf life. However, unlike polystyrene, PHA decomposes in soil and water.
According to the U.S. Environmental Protection Agency, the world produces over 14 million tons of polystyrene each year. After usage, the majority of this plastic is landfilled. Although polystyrene accounts for less than 1% of solid waste generated in the U.S., at least 2.3 million tons end up buried in landfills each year. Only 1% of polystyrene waste is currently being recycled.
Minh Sơn
