Plastic waste is a global pollution crisis. Finding effective solutions to tackle PET plastic pollution is crucial for preserving our environment and creating a more sustainable future.

PET plastic, short for polyethylene terephthalate, is a commonly used material in bottles, containers and packaging. Unfortunately, PET plastic waste has become a significant environmental problem. When not properly recycled, PET can persist in the environment for many years, contributing to pollution in our oceans and ecosystems.

Current recycling methods for PET plastic face several challenges. The processes can be energy-intensive and costly. And the quality of recycled PET may not always be on par with virgin plastic, limiting its usability.

In 2016 scientists found an enzyme, a special type of protein, called IsPETase that can break down PET into its original building blocks. This discovery generated a lot of interest in using biological methods to recycle plastics.

But enzymes such as IsPETase are not immediately suitable to be used on a large scale, as they are not robust or efficient enough for industrial use. Whilst enzymes can be engineered to meet these industrial demands, the process is very challenging when working with plastic degrading enzymes.

In this recording of an online talk, Dr Elizabeth Bell describes the development of a high-throughput platform for engineering plastic degrading enzymes using a process called directed evolution. Directed evolution is a mimic of natural evolution but done on a laboratory scale. It focuses on tailoring the specific properties of an enzyme to meet our requirements.

Elizabeth and her team used this platform to create a new variant of IsPETase that can withstand high temperatures and is more effective at breaking down PET. The engineered enzyme can also selectively degrade the PET component of a multi-material plastic that is commonly used for food packaging.

This study demonstrates that laboratory evolution can be used as a powerful tool to engineer enzymes to effectively break down plastics. With further research and development, these engineered enzymes could play a crucial role in reducing plastic waste and promoting a more sustainable future.

What is the best way to think about the world? How often do we consider how our own thinking might impact the way we approach our daily decisions? Could it help or hinder our relationships, our careers or even our health?

Acclaimed mathematician David Sumpter has spent decades studying what we could all learn from the mindsets of scientists. His book Four Ways of Thinking (published August 2023) is the result.

Thinking about thinking is something we rarely do, yet it is something science questions all the time. Rather than being about facts, scientific and mathematic disciplines are, in large part, about finding better ways of reasoning. Our primary mission is to shape our own minds in a way that gets us closer to the truth.

In this recording of a Manchester Lit & Phil talk, David illustrates four ways of thinking (Statistical, Interactive, Chaotic and Complex) through the lives of four mathematical scientists — Ronald Fisher, Alfred Lotka, Margaret Hamilton and Andrej Kolmogorov. But that doesn’t mean you have to be a mathematician to enjoy David’s presentation!

He combines personal experience with practical advice, showing how these tried and tested methods can help us with every conundrum. From how to bicker less with our partners, to pitching to a tough crowd.

What new technologies are being developed to minimise the long-term storage of spent nuclear fuels?

Nuclear power is very clean and carbon neutral. But spent nuclear fuel has a storage lifetime of 300,000 years.

Reprocessing used nuclear fuel is currently carried out on large scale using the “Plutonium Uranium Reduction and Extraction” (PUREX) process. During this process, the fuel is reduced to 15% of its original weight and the extracted uranium and plutonium are used as “Mixed Oxide Fuel”. This has been carried out at scale by the UK at Sellafield (now curtailed) and continues in France at La Hague.

The residual high-level waste has a storage lifetime of 9,000 years. Much of the remainder of the long-term radiotoxicity of the residual waste is due to traces (0.1%of the original fuel) of the minor actinides. Separating these minor actinides from the chemically very similar lanthanides and other fission products is the next key step in the future reprocessing of spent nuclear fuel.

So, what’s the challenge? The actinides can be used as a fuel in the next generation of nuclear reactors and converted into benign products. But the accompanying lanthanides would “poison” the reactor, causing it to shut down.

In this recording of an online talk, Laurence Harwood reports on the important progress that has been made in the advanced reprocessing of spent nuclear fuel. The used fuel need not be a liability but a source of yet more power.