Plastic is one of the most useful materials ever invented — and one of the most persistent. A typical plastic bottle takes hundreds of years to break down, fragmenting into microplastics that contaminate oceans, soil, and even the human bloodstream. But a team of Chinese researchers may have found a radical solution: turn the plastic itself into a living system that self-destructs.
The study, published in ACS Applied Polymer Materials, describes a new "living plastic" made by embedding dormant spores of the bacterium Bacillus subtilis into polycaprolactone (PCL), a biodegradable polymer commonly used in 3D printing and surgical sutures. The bacteria are engineered to produce two different plastic-degrading enzymes simultaneously. The first enzyme, a lipase, acts like a pair of random scissors, cutting long polymer chains into shorter fragments. The second enzyme, a cutinase, then dismantles those fragments into their basic molecular building blocks.
This two-enzyme strategy is the key innovation. Previous attempts at self-destructing plastics relied on a single enzyme, which worked slowly and left behind partially degraded material. The dual-enzyme system from the Chinese team — led by researchers at the Technical Institute of Physics and Chemistry of the Chinese Academy of Sciences — achieves complete degradation in just six days, leaving no measurable microplastic residue behind.
The spores remain dormant during the plastic's normal service life, protected by the PCL matrix. Only when the material is exposed to specific triggers — such as the moisture and microbial activity in a landfill or compost environment — do the spores germinate, the bacteria begin producing enzymes, and the plastic starts breaking down from within. The mechanical properties of the living plastic are nearly identical to those of standard PCL, meaning it can be processed and used in the same ways.
While the technology is still in the lab stage, the implications are significant. Single-use plastics, agricultural films, and medical devices that naturally degrade on command could dramatically reduce the environmental burden of plastic waste. The researchers estimate that scaling up the production process and adapting the system to other common plastics, such as polyethylene and polypropylene, could be the next major milestone.