The plastics sustainability crisis has prompted a surge in development of novel polymers which are designed for deconstruction under defined and mild conditions after consumer use. These offer an exciting route to a circular plastics lifecycle, where materials can be deconstructed and the monomers re-entered into the polymers industry to generate high value second generation materials ( ACS Sustain. Chem. Eng. 2024 , 12 (20), 7748–7756).

At present, the building blocks of these next-generation polymers are based on petrochemical-derived feedstocks. These petrochemicals are processed via chemical means to generate monomers, which are then polymerised to produce the next-generation plastic. We hypothesise that ‘next-generation monomers’ could instead be accessed via novel biosynthetic pathways that use renewable or waste feedstocks as carbon source ( RSC Sustain. 2025 . https://doi.org/10.1039/D5SU00013K ). This would de-fossilise the supply chain and align the lifecycle of these emerging materials with the bioeconomy.

To do this, this PhD project will focus on engineering novel biosynthetic pathways in common Industrial Biotechnology hosts (e.g . Escherichia coli and/or Pseudomonas putida ) to produce the target monomer for a promising novel polyhydroxyalkanoates (Science 2023, 380, 6640). This will involve identification of suitable enzymes capable of catalysing the individual pathway steps, followed by assembling them into a suitable microbial pathway. Depending Enzyme engineering may also be required to improve the biocatalyst performance to access high titres of the target molecule.

This project is part of the Preventing Plastic Pollution using Engineering Biology (P3EB) Mission Hub. P3EB is a pioneering initiative aimed at transforming end-of-life plastic waste using cutting-edge engineering biology technologies. Working in partnership with industry, we will impart value into plastic waste, incentivising its recovery and retention, and so reducing the amount destined for landfill, for incineration, or being discarded into the environment.

The P3EB Mission Hub is a consortium of researchers and innovators assembled from the University of Portsmouth (lead), University of Edinburgh, Bangor University, University of Cambridge, Imperial College London, University of Manchester and University College London. The initiative will receive £11.2 million from the “UKRI Technology Missions Fund” over the next 5 years. As a PhD student affiliated to P3EB, you will have access to this UK-wide network and benefit from its depth of expertise in the field of plastics sustainability.