Scientists have created a new category of material called living plastic that incorporates biological degradation mechanisms directly into its polymer structure. These plastics contain dormant microorganisms capable of breaking down the surrounding material when activated, presenting a departure from conventional approaches to polymer disposal. A study published in ACS Applied Polymer Materials describes a prototype that achieved complete decomposition within six days while avoiding the formation of microplastics during the breakdown process.
The research team engineered Bacillus subtilis bacteria to produce two complementary enzymes that work sequentially to degrade polymers. The first enzyme cleaves long polymer chains at random intervals, creating shorter segments, while the second enzyme systematically breaks these fragments down into their constituent monomer building blocks. This two-enzyme approach proved more efficient than earlier living plastic designs that relied on single enzymes, as it enabled thorough degradation without leaving fragmented plastic particles behind.
For their experiments, researchers incorporated dormant bacterial spores into polycaprolactone, a polymer commonly used in three-dimensional printing and medical sutures. The material retained mechanical properties comparable to conventional polycaprolactone films under normal storage conditions, indicating that the addition of spores did not compromise functionality. When researchers introduced a nutrient broth heated to 50 degrees Celsius, the spores activated and began producing the degradation enzymes, leading to complete decomposition within six days.
The team demonstrated the technology’s potential application by fabricating a wearable plastic electrode from the living material. The device functioned normally and then fully degraded within two weeks following activation. Researchers indicated plans to extend this approach by developing activation methods suitable for aquatic environments, where substantial plastic pollution occurs. They also suggested that the same biological strategy could potentially be adapted to other polymer types commonly used in single-use products.