A plastic that self-destructs only upon contact with the ground. This is the latest innovation enabled by plastic-eating bacteria, the application of which is being perfected at the University of San Diego in California. According to scientists from La Jolla University, the new type of polyurethane could arrive on the market in a few years, making it possible to mitigate the age-old problem of plastic dispersion in the environment. Unlike other types of plastic that self-digest, in fact, the material under study has the ability to begin the decomposition phase only when it comes into contact with the reagents present in the soil, allowing it to be used without problems during its life cycle, which is not limited by an expiry date.
The genetically modified bacterium
A scenario is thus envisaged in which the disposal of coverings, insulation, mattresses, shoe soles and many others currently made of polyurethane can be disposed of in a simpler way. Not only. “Our process makes the materials more robust, therefore prolonging their useful life,” said co-researcher Jon Pokorski quoted by BBC. “And then once it’s done, we’ll be able to eliminate it from the environment, regardless of how it’s disposed of.” Scientists managed to achieve this by genetically modifying a bacterium normally used as a probiotic – the Bacillus subtilis – so that it is able to withstand the high melting temperatures of plastic.
Possible problems
Not everyone, however, agrees with the introduction of materials like this. According to some experts, having these polymers available could encourage the consumption of plastic, including that of materials not yet digestible by bacteria, having the opposite effect to the desired one. Professor Steve Fletcher, director of the Revolution Plastics Institute at the University of Portsmouth told the BBC: «We need to pay attention to potential solutions of this type. They may give the impression that we should worry less about plastic pollution because any plastic released into the environment will degrade quickly, and ideally safely. However, for the vast majority of plastic, things are not like this.”
