Eating away at the plastics problem

It is estimated that 88 million tonnes of plastic waste leaks into the oceans each year and there will be more plastics in the ocean than fish by 2050.

Banning single-use plastic is not a solution as this would increase food waste resulting in increased carbon dioxide emissions, contributing to global warming, and burning it would also be environmentally damaging. The sustainable solution is to recycle plastics.

UCL’s approach is that waste is a failure of design, whether that is a failure to design plastics to be reusable, recyclable, or compostable or a failure of infrastructure or economics.

The team in UCL Biochemical Engineering is leading on the development of ways of designing biology to break down waste plastic and then turn it into a material we can use, and do it in a sustainable way.

There are bacteria that can break down plastics, such as Ideonella sakaiensis, by making the enzyme PETase that eats away at the structure of the PET plastic used in plastic water bottles.

What we need to find are more enzymes and microbes that can eat away at other types of plastic, do it faster and make new chemicals and materials.

A major advantage is that they do the work without having to melt the plastic, and without having to use large amounts of energy, large quantities of chemicals, such as acids, making recycling much more sustainable.

The Synthetic Biology team at UCL Biochemical Engineering are using a technique called “accelerated evolution,” sometimes known as test-tube evolution, to speed bacteria’s evolution to create new mutations.

The team will use the same directed evolution to look at ways of taking the biomass and turning it into reusable materials, again in water and in mild, sustainable conditions.

Biochemical engineers will investigate how to “scale-up” the process from laboratory-scale, to mass-manufacture in a factory.

Image credit: Naja Bertolt Jensen on Unsplash.