Self-destructing plastic was invented. The material contains a species of bacteria

An international team of scientists has succeeded in designing a biodegradable material composed of bacteria with the ability to decompose at the end of its useful life, thus bringing a ray of hope in the face of one of the most serious environmental problems, air pollution plastic, reports EFE, taken over by Agerpres.

“Living plastic”, as researchers define it in a study published on Tuesday in the journal Nature Communications, is a soft thermoplastic polyurethane material that can be used in the production of shoes, mats, pillows or memory foam.

A bacterium included in the manufacturing process

The material is composed of bacterial spores of a strain of Bacillus subtilis, a common soil bacterium that, when exposed to the nutrients present in compost, germinates and decomposes this plastic material at the end of its life cycle. “This is an inherent property of these bacteria,” explained one of the study’s authors, Jon Pokorski, professor of nanoengineering at the University of California, San Diego, United States.

Scientists used bacterial spores because of their resistance to harsh environmental conditions. Unlike fungal spores, which have a reproductive function, bacterial spores possess a protective protein shield that allows the bacteria to survive in a vegetative state.

To manufacture the new biodegradable plastic, the researchers introduced spores of Bacillus subtilis and granules of thermoplastic polyurethane into a pressing machine, where the two components were mixed and melted at 135 degrees Celsius. The researchers then evaluated the biodegradability of the resulting material by placing it on biologically active and sterile compost residues at 37 degrees Celsius with a relative humidity of 44-55%. Water and other nutrients from the compost triggered spore germination in the plastic, which was 90% biodegraded within five months.

“Most of these plastics are unlikely to end up in microbe-rich composting facilities. Therefore, this ability to self-degrade in an environment without additional microbes makes our technology even more viable,” said Pokorski, quoted in a press release.

Industrial scale production, the next step

The researchers admit that they have not yet studied the remains of the decayed material, but believe that the persistent bacterial spores in it would be harmless, as Bacillus subtilis is a strain used in probiotics and is generally considered harmless to humans and animals, and even beneficial to plant health. .

In this study, bacterial spores were modified to withstand the high temperatures required to produce the polymer. “We evolve the cells again and again, until we arrive at a strain optimized to tolerate the heat,” explained another author of the study, Adam Feist, a researcher at the same university.

Although the current study focuses on producing a small amount of the new plastic on a laboratory scale to test its viability, the researchers are currently working on optimizing the industrial-scale production process of the plastic, which self-destructs at the end of its useful life.