Researchers pushing boundaries for natural solutions to plastic waste

Plastics packaging. Who could have predicted a few decades ago this would become such a hot topic of debate? But at a time when consumers are demanding more environmentally conscious and eco-friendly products from manufacturers—and are turning to competitors with more sustainable options if their favorite brands don’t comply—it’s a subject that must be addressed sooner rather than later. 

Despite the knock and scattered bans on polymers, plastic packaging offers benefits that are difficult to replicate and nearly impossible to duplicate. Plastics are hygienic, secure and light weight, durable and versatile, and can be molded into a nearly endless variety of shapes, colors, sizes and thicknesses.

One of the most popular polymers used in packaging is polyethylene, the downside of which is inherent in plastics: durability. As with most traditional plastics it is slow to degrade, requiring up to four centuries to decompose.  Although some of this plastic is recycled, the bulk of it is not; in 2014 the EPA noted of the 33.25 million tons of plastic generated in the USA, 9.5% was recycled and 15% was burned for energy, with more than 75% relegated to landfill disposal.

What can be done about PE and, potentially, other potentially environmentally problematic polymers after use? One intriguing possibility was found by a happenstance.AX Control Caterpillar eats plastic sustainable

In 2017, Spanish researchers made a chance discovery that may one day help change those numbers for the better. It seems the wax worm caterpillar (Galleria mellonella) that typically feeds on honeycomb also has a taste for plastic. 

Research scientist and amateur beekeeper Federica Bertocchini happened to notice an infestation of wax worms in one of her beehives.  She removed the worms and placed them in a poly bag for later disposal.

When she returned later, the worms had eaten their way through the PE bag and escaped

Bertocchini and her colleagues at the Institute of Biomedicine and Biotechnology began studying the wax worms immediately. Further research indicated the caterpillar likely produces an enzyme that can degrade the plastic through consumption or through contact to the caterpillar’s chrysalis. While a second test at Johannes Gutenberg University Mainz disputed Bertocchini’s findings, her work is ongoing with additional findings expected.

This solution is literally underfoot

Perhaps more promising is the work at the Kyoto Institute in Japan done by Kohei Oda, whose team discovered certain soil bacteria can break down and consume polyethylene terephthalate (PET.)  Familiar as a stable polymer, PET is considered to be inert and resistant to biological degradation. However, Oda’s team has identified and isolated a type of bacterium (Ideonella sakainsis 201-F6) that can degrade, assimilate, and hydrolyze PET into MHET (monomeric mono-2-hydroxyethyl terephthalate) and from there, into ethylene glycol and terephthalic acid, which can then be further degraded into carbon dioxide and water.  

While neither of these scientific teams is close to moving these natural discoveries into large-scale solutions to solve plastic waste problems, it is encouraging to know they and others are actively searching…and that the awaited breakthrough may be discovered in the next test.

 

Marla Keene is a technical writer for AX Control, Inc. (Fuquay-Varina, NC), where she has written content for sites like Ansi.org, Embedded-computing.com and Shapeways.com. Before her current position, Keene attended Furman University in Greenville, SC , and ran her own small business for 12 years.

Image courtesy Pixaby

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