BIOSCIENCE FOR RENEWABLE RESOURCES AND CLEAN GROWTH - Bioengineering novel platforms for one-pot plastic upcycling

Background:
Plastic pollution is a major environmental threat and sequesters carbon-rich materials derived from finite, petrochemical resources. Environmental, sustainability and economic drivers demand that we develop novel and robust technologies to tackle the plastic waste crisis and move towards a circular economy through valorisation of post-consumer materials. The young fields of plastic degradation and plastic upcycling are advancing rapidly to address this challenge. Notably, numerous enzymes have been reported to degrade polyester substrates under mild reaction conditions, including engineered variants of PETase (Ideonella sakaiensis) and leaf branch compost cutinase. Furthermore, we and others have demonstrated the potential of bio-based plastic upcycling pathways to convert low-value, post-consumer plastics into high-value small molecules such as the flavour molecule vanillin (Green Chem., 2021, 23, 4665-4672). Importantly, these target molecules are predominantly currently synthesised directly from finite petrochemical resources. However, plastic degradation efficiencies remain a major bottleneck and robust technologies to interface plastic degradation with upcycling pathways are lacking.

The project:
This highly interdisciplinary project will harness the latest developments in plastic degradation, synthetic biology and biocompatible chemistry to develop novel enabling biotechnologies to directly interface polyester degradation with bio-based upcycling pathways. We will initially focus our attention on optimisation of microbial biofilms for adhesion to and depolymerisation of plastic surfaces. We will then explore microbial co-culturing approaches to enable one-pot polyester degradation and upcycling, using our existing vanillin pathway as a model system. This will include exploring opportunities for incorporating non-enzyme catalysed, biocompatible chemistry approaches (RSC Chem. Biol., 2021, 2, 1073-1083) to improve the efficiency of plastic degradation. Whilst initial studies will focus on PET degradation and upcycling, the degradation and upcycling of other polyester materials such as PLA and PEF will also be explored in the later stages of the project.

The project will be suited to students from biology or bioorganic chemistry backgrounds with previous experience in biocatalysis, synthetic biology, biocompatible or bioorganic chemistry.

Training environment:
This project will be supervised by Dr Joanna Sadler and Dr Stephen Wallace at the Institute of Quantitative Biology, Biochemistry and Biotechnology (IQB3) at the University of Edinburgh. The research will provide multi-disciplinary training spanning synthetic biology, biocompatible chemistry, plastic degradation and biocatalysis. The successful candidate will also benefit from strong links with the SynthSys centre, the Edinburgh Genome Foundry, the School of Chemistry and various industrial partners.