Synthetic biology can be used to decompose PET plastic packages to create a circular economy and sustainably manage plastic pollution.
Authored by: Megan
Andrew N. Liveris Academy for Innovation and Leadership at The University of Queensland, Brisbane.
How many plastic products can you see: a water bottle, a pen, a phone case? Plastic is waterproof, versatile and cheap. It has pervaded every aspect of life and recycled products are not economically competitive. Phenomena like The Great Pacific Garbage Patch, a massive gelatinous layer of microplastic covering the ocean’s surface, is a visceral reminder that plastic has got to go1.
One solution is to refuse single use plastic, adopting reusable containers when possible and plastic alternatives. However, this will not work in isolation. In the food industry, plastic packaging, normally PET, is the only packaging compliant with the high hygiene standards set by supermarkets2. An interesting solution for better management of plastic is emerging in the field of synthetic biology. Synthetic biology can be used to create PET plastic products in a closed-loop system, rather than oil3. This creates a circular PET economy beyond the current recycling process.
Recycling is not a viable solution to plastic pollution. This system breaks the plastics down into small black beads which are then sorted and remade into the same materials1. It gets harder and harder to sort the beads each time and products can only be successfully recycled approximately 10 times1. This system is a dismal flop – it is not economically competitive and less than 30% of products are recycled in developed countries2.
However, synthetic biology is revitalising this broken system for PET packaging. Through a process called hydrolysis, scientists can manipulate enzymes from microorganisms to degrade the plastics more efficiently and effectively into small molecules3. These molecules are then easier to sort and can be used by metabolic engineers and synthetic biologists to create a range of products – including PET packaging3. These developed materials have multiple uses making this process economically competitive as well as a closed-loop environmentally friendly solution.