Invented in 1907, plastics have grown in popularity for their convenience and disposability. However, plastics are now becoming a cause for concern due to its poor degradability.
The scale of the problem is large. Researchers estimate that since the 1950s, more than 8.3 billion tonnes of plastic has been produced. About 60% of that plastic has ended up in either a landfill or the natural environment. Of this, much of the plastic ends up in oceans and it is estimated that plastic will outweigh all the fish in the ocean by ocean by 2050.
Only about 9% of all plastic waste is regenerated. So, what happens to the rest. A recent story piqued my interest. A handful of microbes have evolved with the ability to “eat” plastics. These microbes break down the component molecules of the plastic. You may ask, this is an old hat, so what’s new. While the first plastic-eating microbe was discovered in 1990s, there has been steady progress in the field. They’ve now evolved to the bacterium that uses plastic as their sole food and energy source. Researchers are, now, creating industrial-scale super enzymes that could eat PET six times faster than earlier. Scientists are looking at microbial DNA from a range of habitats. In areas with high levels of plastic pollution, the researchers found that the microbes were more likely to have enzymes with plastic-degrading tendencies. One study has found a soil bacterium that feeds on some components of polyurethane.
Pilot projects have started utilising these technologies. For instance, the University of Portsmouth has set up Revolution Plastics, which aims to forge links between academics and industry. Carbios, a French biotechnology company, runs another project.
The main advantage of plastic-eating enzymes is that it makes it possible to recreate plastic to the highest quality. This is unlike recycling, where the quality of plastic degrades after every round of recycling. Thus, these advances are a boon to the circular economy.