A Biological Solution To Plastic Waste

The clothes, carpets, and single-use drink bottles are made up of polyethylene terephthalate (PET) plastic which constitutes of ethylene glycol(EG) and terephthalate (TPA) as its chemical building blocks. Earlier devised methods and researches showed that the degradation of TPA seemed unfeasible. In the year 2018, a research team led by Professor Jen DuBois of Montana State University and Professor John McGeehan of the University of Portsmouth put together a natural enzyme that could degrade the PET plastic to its components. The enzymes namely PETase and MHETase helped in the break down of the PET polymer to its corresponding monomeric units EG and TPA. In the words of Prof. DuBois, out of the two components of PET, EG could be easily used for many purposes including its use as an anti-freeze in cars. But, TPA had no other potential uses beyond PET. Thus, it was necessary to find a method to break down the TPA molecule further to simpler molecules.

Keeping this as the motive, the team further continued with their research to synthesize an enzyme that is capable of degrading TPA. They were able to achieve success when the team from Portsmouth led by Prof. McGeehan developed an enzyme, TPADO which recognized TPA similar to that of a hand in a glove, and the team led by Prof. DuBois, MSU was able to showcase its efficiency in breaking down TPA.
The Director of the University’s Centre of enzyme innovation, Professor McGeehan states that there has been an immense amount of progress in the past years with regard to the development of enzymes that are able to breakdown PET plastic into its chemical building units. He also emphasized on how the simpler molecules formed by the degradation of enzyme can be used by bacteria to produce valuable products from plastic waste which are sustainable in nature. They were also able to obtain a 3-D structure of the TPADO enzyme along with gathering information on the mechanistic process of its reaction. This is thought to provide help in further research to synthesis more faster and efficient versions of the enzyme.

This research provided a breakthrough to tackle the accumulating and challenging plastic pollution and, it paved way for degrading plastic items into valuable chemicals through biological actions.

Reference: University of Portsmouth