CORDIS - EU research results

Ultrahigh-throughput protein evolution for polyethylene biodegradation

Project description

On the trail of the most potent enzymes to biodegrade plastic pollution

Mass production of plastics began about 60 years ago. Plastics have provided great convenience regarding food and beverages in addition to enhancing the properties of materials in fields from transport to construction. However, despite years of efforts to establish plastic recycling policies and processes, more than 90 % of plastics – billions of tonnes over the years – have not been recycled. Polyethylene is the most widely used plastic in the world, found in products from plastic food wrap and shopping bags to detergent bottles and automobile fuel tanks. The EU-funded UTPE PEB project is streamlining the search for enzymes that could biodegrade polyethylene efficiently. After selecting the most promising candidates, the team plans to express and optimise them in an evolutionary way, creating a solution to a growing problem for the planet and its varied ecosystems.


The build-up of plastic pollution is one of the most pressing environmental concerns. Polyethylene (PE), the most abundantly produced plastic polymer, can persist in nature for over a century. The microbial biodegradation of PE that has been observed is slow and inefficient. So far no effort has been undertaken to improve the efficiency of enzymes involved in the biodegradation of PE through directed protein evolution. Standard assays for measuring degradation rates are not sufficiently high-throughput to cover the sequence space required. I propose to use state-of-the-art protein evolution technology to overcome this problem in two ways. First, an ultrahigh-throughput microfluidics based approach, that can associate a given genotype with its phenotype in picoliter sized water-in-oil droplets, will be used to isolate the desired genotypes from a random mutagenesis library. Second, a novel assay for measuring polymer concentration within each droplet based on differential light scattering as the polymer is degraded will assay the PE degradation rate for a given enzyme. These techniques were developed in the research group of the proposed host, Dr. Hollfelder in the Department of Biochemistry at the University of Cambridge. Using these techniques, I will functionally express and evolutionarily optimise a range of PE degrading enzymes in genetically tractable host strains, creating a chassis to investigate the potential of microbial biodegradation as a solution to plastic waste. Secondments at the EBI, UCL and the SME Drop-Tech will convey practical skills in bioinformatics screens and droplet formation. The host group’s experience in enzyme biotechnology and directed protein evolution as well as its extensive modern facilities for microfluidics, next generation sequencing and flow cytometry will synergize with my personal research experience in synthetic, molecular and microbiology to find a multidisciplinary solution to the growing problem of plastic degradation.


Net EU contribution
€ 224 933,76
CB2 1TN Cambridge
United Kingdom

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East of England East Anglia Cambridgeshire CC
Activity type
Higher or Secondary Education Establishments
Total cost
€ 224 933,76