Scientists have managed to find a novel way to get rid of plastic so it doesn¡¯t land up in plastic waste. They have created a mutant bacterial enzyme that is able to break down plastic bottles for recycling within hours.
As can be understood, the real purpose behind the development of the enzyme was recycling of waste. Carbios, almost a decade old company responsible for its production, hopes to conduct industrial-scale recycling within the next five years.?
The enzyme was originally discovered in a compost heap of leaves. In a later experiment, it was able to reduce plastic bottles to chemical building blocks. These blocks were then used to make high-quality new plastic bottles. No other plastic recycling technique is able to do this.
Carbios has partnered with majors like Pepsi and L¡¯Or¨¦al to accelerate development. Of the enzyme. The general notion in the industry is that the new enzyme is a major advancement in the field of recycling.
The capability to break down plastics like this highlights an important possibility, that of a world using plastics in daily lives but not harming the environment in any way. That is why the company insists that plastic, as a strong, lightweight material is very useful and its true recycling is the solution to curb pollution resulting from it.
Now published in the journal ¡®Nature¡¯, the research around the new enzyme began with the screening of 100,000 micro-organisms for promising candidates. This list included the leaf compost bug, first discovered in 2012, which ultimately ¡°turned out to be the best,¡± as per Prof Alain Marty at the Universit¨¦ de Toulouse, France, the chief science officer at Carbios.
The scientists then introduced mutations to the enzyme to enhance its degradation abilities. This included making the enzyme stable at 72 degree celsius i.e. the ideal temperature for fast degradation. The target was to break down the PET plastic from which drinks bottles are made.
Before the enzyme is put to use, the waste plastic bottles are ground up and heated. The enzyme is then added to the mix at around the temperature mentioned above to deliver the best results. The team at Carbios was able to break down a tonne of waste plastic bottles, degrading them for around 90% within 10 hours, using the enzyme.
The recycled material was then used by the scientists to create new food-grade plastic bottles. The whole process, however, makes the recycled PET more expensive than virgin plastic. But Martin Stephan, the deputy chief executive at Carbios, noted that the existing lower-quality recycled plastic sells at a premium due to a shortage of supply.
For industrial scale use, Carbios has a deal with biotechnology company Novozymes to produce the new enzyme at scale using fungi. As per Carbios, the cost of the enzyme was just 4% of the cost of virgin plastic made from oil.
However novel the new enzyme seems, it is not a one of its kind discovery. A newly discovered bacteria by scientists in Europe is a kind of Pseudomonas (a group of strong bacteria), dubbed TDA1 that?loves eating plastic. You can read all about it here.