Microplastics treatment using microbial enzymes

 

DARWIN is participating in the European project ‘Microbial ENZYmes for treatment of non-recyCLEd plastic fractions’ (ENZYCLE), a 4-year BBI-RIA project with €4.5 million in EU funding. The general objective is to valorize and improve non-recycled plastic fractions through enzymatic processes to obtain high value-added products.

 

The project is led by ITENE (Technological Institute of Packaging, Transport, and Logistics) and includes a total of 13 partners from various European countries, including Spain, the Netherlands, France, Austria, Italy, and Germany. Notably, 5 of the participating partners are large companies: Depuración de Aguas de Mediterráneo SL (DAM), Soprema, Greiner Packaging International GmbH, Aliplast SPA, and Indorama Ventures Europe BV.

 

Within a circular economy framework, enzymes with high hydrolytic activity on polyesters (PET) and polyolefins (PE and PP) will be identified and selected, an efficient production process will be established, and specific recycling processes for currently non-recycled plastic fractions will be developed. Additionally, ENZYCLE will address the issue of microplastics and their significant impact on the environment and health.

 

Problem

 

According to expert reports, 29.5 million tonnes of plastic waste were generated in Europe in 2020, with only 35% being recycled (42% incinerated and 23% landfilled). This goes against EU circular economy policy and legislation on waste (Waste Framework Directive 2018/851/EC3, Packaging and Packaging Waste Directive 2018/852/EC4, Landfill Directive 2018/850/EC5).

 

Packaging is the main plastic waste fraction representing about 63% of the total plastic waste generated in Europe. Thus, it is necessary to develop new processes for recycling the currently not valorised plastics, especially packaging multilayer plastics (i.e. PET/PE and PET/PP), post-consumer polyethylene terephthalate trays, clamshell containers and microplastics present in wastewater to reach the European targets (European strategy for plastics aims to achieve the 100% of packaging recyclable or reusable by 2030) and reduce the amount of plastics ending up in the ocean (8 million tonnes each year).

 

Mechanical recycling is not always an option or leads to down-grading of the material, e.g. for multilayer and plastic mixes, biochemical or enzymatic recycling of recalcitrant plastic fractions might form a powerful alternative.

 

Solution

 

The use of enzymes for plastics recycling benefits from their extremely high substrate specificity, a high catalytic power, as well as their sustainability, due to enzymes operate under mild conditions of temperature, pH and pressure and often in aqueous media.

 

The advances in the understanding of microbial functions from an enzyme, to pathways, and entire metabolic networks allow the engineering of complex metabolic functions in microbes.

 

Within the framework of the project, DARWIN will perform the isolation and characterization (using genomic and transcriptomic techniques) of polyolefin-degrading strains and microbial consortia, as well as the identification of the enzymes involved in the degradation process.

 

Completion year: ongoing