Plastic that can break down on its own when it's no longer needed sounds like the stuff of science fiction, but some Chinese scientists have brought the idea closer to reality. Their prototype embeds dormant bacteria inside a polymer, creating a material that can be activated on command and dissolve without leaving behind microplastic fragments.
Scientists at the Shenzhen Institutes of Advanced Technology have developed a “living plastic” with a built-in kill switch. The material contains spores from modified Bacillus subtilis, a common soil bacterium, that remain inactive during normal use.
When exposed to the stimulus, the spores awaken and produce enzymes that eat and digest the plastic from the inside.
The work, published in ACS Applied Polymer Materials, builds on previous living plastic experiments that primarily used a single enzyme.
The team used two separate bacterial strains that work together. One produces Candida antarctica lipase, which randomly cuts long polymer chains into smaller pieces. The other produces Burkholderia cepacia lipase, which "chews" these fragments down to small molecules.
The researchers mixed the dormant spores with polycaprolactone, a polyester used in 3D printing fibers and some dissolvable surgical sutures.
When the plastic was placed in nutrient broth heated to 122 degrees Fahrenheit (50 degrees Celsius), the spores were activated and the membrane was completely degraded within six days.
The researchers reported that the process did not create microplastic particles, which could make it more attractive than conventional biodegradable plastics, which often crumble before fully breaking down.
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https://doi.org/10.1021/acsapm.5c04611
Although the press releases will range from very select to rare, I said I'd pass...because sometimes the editors hide.
