Periodic Reporting for period 4 - MIX-UP (MIXed plastics biodegradation and UPcycling using microbial communities)
Période du rapport: 2023-01-01 au 2024-06-30
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.
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.
The main idea of MIX-UP is to showcase a novel cascade approach to the circularity of the plastic life cycle.
Enzyme Production & Mixed Enzymatic Hydrolysis of Mixed Plastics
Despite their recalcitrance, certain microbes and enzymes can degrade plastics. We have identified and characterized PET, PLA, and PU degrading enzymes and highly engineered them for enhanced activity, stability, and efficiency. Enzyme applications during plastic waste depolymerization have been optimized alongside large-scale enzyme production. These enzymes have also been expressed in mixed cultures within a consolidated bioprocess that includes upcycling.
Microbial Plastics Monomer Metabolism
The metabolites released from PET, PU, PLA, PHA, and PE were fed to specialized microbial communities that converted them into central metabolites. This process provides building blocks for synthesizing novel biopolymers or products like HAAs, vicinal diols, and biosurfactants.
Downstream Processing & Product Recovery
Optimized downstream processing allowed for effective product recovery (e.g. PHAs, HAAs) through conditional release and separation of intracellular products. The remaining recalcitrant (model) residues underwent chemical transformations to break persistent bonds. The entire bioprocess was further refined through metabolic engineering across upstream (strain/microbiome development, protein engineering), midstream (fermentation), and downstream (recovery) processes.
Dissemination
MIX-UP's publication record over 4.5 years is impressive, with over 170 peer-reviewed articles leading to numerous conference presentations. Highlights include contributions at prestigious events like the Gordon Conference and the co-organized Sino-EU Conference in Athens. Our dissemination efforts intensified through weekly blogs on mix-up.eu and active social media engagement across Europe and China.
Exploitation
Academic partners have made significant advancements by developing novel enzymes to address traditional petroleum-based plastics such as PE, PET, and PU and emerging bioplastics like PLA, PBAT, and PHA. Progress has been made in understanding enzymatic degradation techniques for various plastics, including mixed types. Industrial partners/SMEs assessed various bacterial Pseudomonas strains provided by academics to produce medium-chain-length PHA from plastic monomers and scaled up to a 20-liter bioreactor. Another partner successfully synthesized polyols for PU insulation materials using released monomers from hydrolysates at a kilogram scale.
In the final project phase, a TEA demonstrated the economic viability of the MIX-UP approach if more than 60% of plastic waste is hydrolyzable compared to non-hydrolyzable plastics like PP. Sustainable sourcing of plastic creates impact; industrialization efforts by Tsinghua University (spin-off: PhaBuilder) aim for TRL8 realization with an annual production target of 1000 tons of PHB, PHBV, and P34HB under open unsterile conditions with engineered Halomonas sp. — addressing growing demand for bioplastics in China and the EU.
Enzyme Production & Mixed Enzymatic Hydrolysis of Mixed Plastics
Despite their recalcitrance, certain microbes and enzymes can degrade plastics. We have identified and characterized PET, PLA, and PU degrading enzymes and highly engineered them for enhanced activity, stability, and efficiency. Enzyme applications during plastic waste depolymerization have been optimized alongside large-scale enzyme production. These enzymes have also been expressed in mixed cultures within a consolidated bioprocess that includes upcycling.
Microbial Plastics Monomer Metabolism
The metabolites released from PET, PU, PLA, PHA, and PE were fed to specialized microbial communities that converted them into central metabolites. This process provides building blocks for synthesizing novel biopolymers or products like HAAs, vicinal diols, and biosurfactants.
Downstream Processing & Product Recovery
Optimized downstream processing allowed for effective product recovery (e.g. PHAs, HAAs) through conditional release and separation of intracellular products. The remaining recalcitrant (model) residues underwent chemical transformations to break persistent bonds. The entire bioprocess was further refined through metabolic engineering across upstream (strain/microbiome development, protein engineering), midstream (fermentation), and downstream (recovery) processes.
Dissemination
MIX-UP's publication record over 4.5 years is impressive, with over 170 peer-reviewed articles leading to numerous conference presentations. Highlights include contributions at prestigious events like the Gordon Conference and the co-organized Sino-EU Conference in Athens. Our dissemination efforts intensified through weekly blogs on mix-up.eu and active social media engagement across Europe and China.
Exploitation
Academic partners have made significant advancements by developing novel enzymes to address traditional petroleum-based plastics such as PE, PET, and PU and emerging bioplastics like PLA, PBAT, and PHA. Progress has been made in understanding enzymatic degradation techniques for various plastics, including mixed types. Industrial partners/SMEs assessed various bacterial Pseudomonas strains provided by academics to produce medium-chain-length PHA from plastic monomers and scaled up to a 20-liter bioreactor. Another partner successfully synthesized polyols for PU insulation materials using released monomers from hydrolysates at a kilogram scale.
In the final project phase, a TEA demonstrated the economic viability of the MIX-UP approach if more than 60% of plastic waste is hydrolyzable compared to non-hydrolyzable plastics like PP. Sustainable sourcing of plastic creates impact; industrialization efforts by Tsinghua University (spin-off: PhaBuilder) aim for TRL8 realization with an annual production target of 1000 tons of PHB, PHBV, and P34HB under open unsterile conditions with engineered Halomonas sp. — addressing growing demand for bioplastics in China and the EU.
New microbes and enzymes are effectively breaking down recalcitrant plastics. Techniques like synthetic biology toolboxes and engineered microbes enhance plastic monomer metabolization, leading to recyclable products for a circular plastics economy. MIX-UP aims to upcycle mixed plastic waste into sustainable polymers while valorizing multi-million-ton waste streams, reducing environmental impact, and accelerating biotechnology development. With around 4,900 Mt of plastics in landfills, bio-depolymerisation of PET, PU, PE, and PS will yield valuable building blocks with significant market potential. Product modules for HAA, biosurfactants, and antimicrobial polymers will also showcase the bio-production potential of underdeveloped bio-chemicals. Biodegradable polymers can be recycled but break down into CO2, CH4, and water if leaked into the environment.
MIX-UP has achieved significant social impacts:
[i] Economic incentives for waste valorization will boost recycling initiatives.
[ii] Improved enzymatic recycling will reduce waste, visibly lowering municipal waste taxes.
[iii] New production methods and PHA/bio-PU materials will promote biodegradable polymers in the medical, technical, and packaging sectors.
These impacts support MIX-UP's efforts to enhance social acceptance of innovative technologies for a circular bioeconomy.
MIX-UP has achieved significant social impacts:
[i] Economic incentives for waste valorization will boost recycling initiatives.
[ii] Improved enzymatic recycling will reduce waste, visibly lowering municipal waste taxes.
[iii] New production methods and PHA/bio-PU materials will promote biodegradable polymers in the medical, technical, and packaging sectors.
These impacts support MIX-UP's efforts to enhance social acceptance of innovative technologies for a circular bioeconomy.