Chinese Scientists Create Plastic That Can Disappear on Its Own in 6 Days

JAKARTA - Imagine plastic that can "commit suicide" after being used. Chinese scientists have developed "living plastic" that can decompose itself on command without leaving microplastics.

Citing a report by The Independent, Wednesday, May 13, the new material contains microbes that are capable of releasing plastic-degrading enzymes. In a study in the journal ACS Applied Polymer Materials, two common bacterial strains of Bacillus subtilis are said to be able to decompose the material into its basic components in just six days.

"The realization that traditional plastics can last for centuries, while many of their uses such as packaging are short-lived, makes us ask: can we incorporate direct degradation into the material's life cycle?" said study author Zhuojun Dai of the Shenzhen Institute of Synthetic Biology.

According to Dai, by implanting microbes, plastics can "live" and destroy themselves on command. The durability of plastics, which has been a problem, is turned into a programmable feature.

Researchers engineered two strains of Bacillus subtilis. Each produces a different enzyme to break down polymer chains. Polymers are long chains of molecules that are the basis of plastics.

The first enzyme works like a random cutter that breaks long chains into smaller pieces. The second enzyme breaks those pieces from end to end to the most basic components.

In order for microbes not to be inactive before their time, scientists store them in the form of dormant spores. Dormant spores are a "sleeping" condition in bacteria so that they remain stable until they are triggered to be active.

The spores were then incorporated into polycaprolactone, a type of polymer commonly used in 3D printing and some surgical sutures.

When the plastic is put into the nutrient broth and the temperature is raised to 50 degrees Celsius, the spores are active. The bacteria then decompose the material in six days.

The researchers said the cooperation of the two enzymes was more effective than the one-strain bacterial system. As a result, the degradation of polycaprolactone was close to perfect.

The next stage, researchers want to develop a bacterial spore trigger in water, because a lot of plastic waste eventually ends up in the water. They are also targeting similar strategies for other types of plastic, including disposable plastic.