How a bacterium may help solve the plastic pollution crisis

Petroleum-based plastics, including poly(ethylene terephthalate) (PET), are extensively used in everyday products, such as single-use plastic bottles, textiles and food wrappers. While such products are disposed of rapidly after use, they persist in the environment for hundreds of years. The plastic pollution resulting from our throw-away culture has now exceeded manageable levels and is overwhelming the planet's ability to deal with it. The environmental impacts are becoming increasingly obvious, with wildlife and human health increasingly threatened.

Although reducing the manufacture of unnecessary single-use plastics and improving waste management systems will help ease the pollution crisis, our reliance on the convenience of plastic products is unlikely to be abated any time soon. Researchers are therefore looking at alternative approaches to "clean up" the more persistent plastics from our environment and it appears that microbes may offer some promising solutions.

"Certain bacteria harbor the necessary enzymes to degrade PET, the most problematic plastic environmentally," explains senior author Shosuke Yoshida. "Our research has shown that the bacterium Ideonella sakaiensis converts PET into poly(3-hydroxybutyrate) (PHB), a type of poly(hydroxyalkanoate) (PHA) plastic that is biodegradable," he continues.

This finding is particularly promising because it addresses two current problems for the sustainability of plastics: degrading the most persistent form of petroleum-based plastic while sustainably producing biodegradable plastics.

"We believe that this discovery could be significant in tackling plastic pollution," Yoshida states, "as we show that the PET-degradation and PHB-synthesis pathways are functionally linked in I. sakaiensis. This might provide a novel pathway where a single bacterial species breaks down difficult-to-recycle PET plastics and uses the products to make biodegradable PHA plastics."

Given the overwhelming challenge of dealing with worldwide plastic pollution, this novel bacterial approach may be a significant part of the solution.