Introduction

Last month, scientists took an important step towards solving our global plastic waste crisis. They discovered TPADO, a nature-based solution to our collective plastic problem. The answer is an enzyme that can break down terephthalate (TPA). TPA is one of the building blocks of Polyethylene Terephthalate Plastic (PET). We use PET to make our clothes, carpets, and single-use water bottles.

Professor Jen DuBois from Montana State University and Professor John McGeehan from the University of Portsmouth co-led the research. We do not use TPA anywhere else besides PET. Most bacteria cannot even recognize TPA. However, the team from Portsmouth demonstrated that an enzyme from the bacteria consuming PET easily recognizes TPA. The research team from Montana State University then showed that the enzyme, which they called TPADO, can break down TPA with surprising efficiency.

The scientists hope that their outstanding work will help in safely disposing of the 400 million tons of plastic produced each year. They also hope that their ground-breaking work will open new doors to discovering and improving enzymes like TPADO. Their work will hugely help governments and organizations tackle plastic pollution. The enzymes can create biological systems that transform plastic waste into beneficial products.

Professor McGeehan says that the last few years have witnessed phenomenal advances in the engineering of enzymes breaking down PET plastics into their basic structural blocks. Their work, however, goes one step further. They have shown how enzymes can break down those basic structural blocks into even simpler molecules for the first time. Bacteria can then use these molecules and generate natural materials and chemicals, turning plastic waste into essential and valuable products.

The enzymes break down plastic waste in just a few days. Plastics typically take around 450-500 years to decompose.

The research that led to the discovery of TPADO was a part of an international collaboration between the UK and the US. The work brought together researchers from various scientific fields to help fix our collective problem as humans: plastic waste.

Prior Research

Over the last five years, many scientists have succeeded in achieving breakthroughs regarding enzymes digesting common plastics such as PET. Scientists have pursued a circular economy for plastic waste for a long time. Developments in recent years showed just how far biological engineering could go in solving our world’s problems. These developments have made many people optimistic about our future as humans and the future of our planet.

In 2016, Japanese scientists discovered a bacterium that naturally consumed PET plastics. The bacterium used enzymes to break down plastic waste in a time span of a few weeks. 2020 witnessed the discovery of ‘PETase’. PETase was a better performing version of the Japanese discovered bacterium enzyme. Scientists found that when they combine a super enzyme called ‘MHETase’ with PETase, it could break down the plastic at six times the speed of the earlier enzymes.

The Plastic Problem

The plastic waste problem is an environmental crisis that began nearly 70 years ago. Scientists have predicted that by 2050 we will have more plastic than fish in our oceans. Environmentalists consider plastic waste as one of the world’s biggest environmental threats facing animals and humans.

The widespread use of plastic started after World War II. Since then, humans have created and dumped 9 billion metric tons of plastic. Plastic does not degrade completely. Instead, it breaks down into tiny pieces. This means that much of the plastic created 70 years ago still exists on Earth! Our collective problem as a society is too much plastic. Finding solutions to our plastic problem is challenging.

For decades, people have considered recycling to be one of the solutions. But, the way we recycle our waste is part of the plastic problem. Most of the western countries send their plastic waste to Asian countries, particularly in Southeast Asia. The western nations diverting their waste opened up a host of illegal markets in Asia.

The convenience plastic offers led humans to develop a throw-away culture regarding their waste. Plastics revolutionized medicine by helping researchers create life-saving devices, made space travel possible and saved lives through helmets and incubators. Most of the plastic we use today has a lifespan of merely a few minutes to some hours. Yet, this plastic remains in the environment for hundreds of years.

In 1950, plastic production was 2.3 million tons. This figure rose exponentially to 448 million tons by 2015. Experts predict that this number will double by 2050. In coastal countries, about 8 million tons of plastic waste carried by winds and rivers escapes into the ocean every year.

Plastic waste affects millions of animals, from birds to fish. Nearly every seabird species consumes plastic. Plastic waste mainly affects marine animals by entangling and starving them. Animals die by starvation due to plastics because their stomachs are so packed with waste that it significantly reduces their urge to eat. Abandoned fishing gear strangles whales, turtles, seals, and other marine animals. Scientists have found microplastics in mussels, shrimp, and fish, and we consume those!

Conclusion

We’ve just read about how plastic pollution is destroying our environment, animals, and public health. Today, plastic waste is one of the world’s greatest environmental threats, which is why scientific breakthroughs like TPADO are desperately needed. Enzymes like TPADO break down plastic into its basic molecules so that we can use those and make new plastic products. These enzymes help us maintain a circular loop of plastic production and consumption. The discovery of these enzymes means we can have a quicker, less energy-intensive, and greener plastic recycling process. The enzymes work on plastic at ambient temperatures and pressure, reducing the need for the conventional plastic recycling method of having to heat it to hundreds of degrees. The discovery of enzymes such as TPADO will help humans develop biological systems that can break down plastic waste naturally and without releasing toxic material. However, scientists have expressed that they are unsure whether we can use enzymes like TPADO on a commercial scale. But, with this breakthrough, researchers are highly optimistic and continue their efforts to discover a solution to the world’s plastic waste problems. Keep your eyes peeled for an incredible leap in the near future.