While total plastic produced in the EU is shrinking, its use is not, and as is the world's plastic, but instead growing at an impressive annual rate of 2-4 %, breaching a staggering 400 million tons per year (Mt) in 2023 and a forecasted 800 Mt by 2050. In 2016, the US, with 42 Mt, was the highest in plastic-waste generation, succeeded by the EU (29.8 Mt), followed by countries with the highest populations (India & China). Only a small fraction (12%) of that plastic is recycled, and of that, only 10% has been reused more than once. The 7 main plastic polymers account for 92% of all primarily produced plastic ever made (1950-2015: 8,300 Mt). The largest groups are PE > PP> PVC, followed by PET, PU, and PS.
The EC is transforming the EU into a resource-efficient economy focusing on plastic waste, shifting from linear value chains to a circular bioeconomy. Effective recycling remains challenging, as plastics degrade with each cycle. Beyond technological solutions, fundamental behavioral changes are necessary to combat the throw-away mentality associated with single-use plastics and excessive packaging. The MIX-UP project aims to support the EC's vision by researching innovative ways to valorize mixed plastic waste streams. Guided by the '6 R' principles (rethink, refuse, reduce, reuse, recycle, replace), MIX-UP seeks to engage both industry and public interest in establishing a sustainable plastic economy. This initiative involves collaboration between two consortia from the EU and China and includes 7 universities, 3 research centers, and industry partners. By unlocking mixed plastics as carbon sources for biotechnological conversion into value-added biodegradable products using heavily engineered enzymes for depolymerization and mixed microbial cultures for upcycling, MIX-UP addresses urgent needs in creating a circular bioeconomy.
In MIX-UP, we worked on novel technologies contributing to i) Additional end-of-life options, ii) Reducing fossil resource use, iii) Circular plastic economy, and thereby iv) Strengthening the EU competitive position. We worked on cascade solutions in MIX-UP, utilizing the best of the two worlds of catalysis in the chemical realm and the fields of biology. The outlook is bright, with ever i) better enzymes for polymer degradation, ii) better microbes for monomer utilization and bioplastic production, and iii) better processes that move the technology to industrial relevance. Highly active enzymes making recalcitrant polymers available for (selective) reuse were discovered and developed. New microbes engineered to produce new types of biodegradable plastics, set up processes to reduce resource use and contributed to delivering competitive quality and pricing. By this, we achieved all proposed objectives to the point. These collaborative efforts within the MIX-UP framework advance scientific understanding and contribute to practical solutions addressing plastic waste challenges while promoting sustainable practices and waste management across multiple sectors.
