MIXed Plastics Biodegradation and UPcycling Using Microbial Communities: The EU Horizon 2020 Project MIX-UP

Abstract

This article introduces the EU Horizon 2020 research project MIX-UP, “Mixed plastics biodegradation and upcycling using microbial communities”. The project focuses on the ambitious vision to change the traditional linear value chain of plastics to a sustainable, biodegradable based one. In MIX-UP, plastic mixtures containing five of the top six fossil-based recalcitrant plastics (PE, PUR, PP, PET, and PS), along with upcoming biobased and biodegradable plastics (bioplastics) such as PHA and PLA, will be used as feedstock for microbial transformations. The generated new workflow increases recycling quotas and adds value to present poorly recycled plastic waste streams. Consecutive controlled enzymatic and microbial degradation of mechanically pre-treated plastics waste combined with subsequent microbial conversion to polymers and value-added chemicals by mixed cultures. Through optimization of known plastic-degrading enzymes by integrated protein engineering, high specific binding capacities, stability, and catalytic efficacy towards a broad spectrum of plastic polymers under high salt content and temperature conditions will be achieved. Another focus lies in the search and isolation of novel enzymes active on recalcitrant polymers. MIX-UP will also enhance the production of enzymes and formulate enzyme cocktails tailored to specific waste streams. In vivo and in vitro application of these cocktails enables stable, self-sustaining microbiomes to convert the released plastic monomers selectively into value-added products, key building blocks, and biomass. Any of the remaining material recalcitrant to the enzymatic activity will be recirculated into the process by physicochemical treatment. The Chinese-European MIX-UP is a multidisciplinary and industry-participating consortium to address the market need for novel sustainable routes to valorize plastic waste streams. MIX-UP realizes a circular (bio) plastic economy and will contribute where mechanical and chemical plastic recycling show limits.

Biologically engineered microbes for bioremediation of electronic waste: Wayposts, challenges and future directions

“…The Chinese–European MIX‐UP project, for example, endeavours to create a novel workflow to recycle plastic waste through the use of heavily engineered enzyme cocktails. [82] Through the application of the ‘design, build, test, and learn’ strategy in the engineering of the microbes, synthetic biology can enable a systematic and iterative construction of the engineered microbes and feedback loop analyses. [47] To facilitate genetic engineering, toolkits containing standardised genetic parts for building transcriptional units and operons are needed to generate mutant libraries in vitro for the selection of desirable phenotypes.…”

“…[65] Riding on this approach is the EU Horizon 2020 research project MIX-UP-Mixed plastics biodegradation and upcycling using microbial communities, which ambitions to explore novel sustainable routes to valorise plastic waste streams. [82] The project aims to work towards controlled enzymatic and microbial degradation of pre-treated plastic waste using heavily engineered, plastic type-specific enzyme blends, and subsequent microbial conversion to polymers and value-added chemicals by self-sustaining microbiomes.…”

Computational exploration of bio-remediation solution for mixed plastic waste

“…It is a challenging and significant bottleneck in designing a cyclic and eco-friendly solution. Using mixed plastic waste for downstream processing could be the best cost-effective move to develop an inexpensive solution (Ballerstedt et al ., 2021).…”

“…This research work explored the feasibility of a functional bio-based solution for accumulated mixed plastic waste. The collected utilization of mixed plastic types is a prerequisite for any large-scale affordable solution (Ballerstedt et al ., 2021). In the present manuscript, we have collected the previous reports of biodegradation of plastic material and analysed the pattern of biodegradation of different plastic types to test if a joint consortium of microbes is practically possible to degrade mixed plastic waste.…”

Toward Microbial Recycling and Upcycling of Plastics: Prospects and Challenges

“…Enzyme cocktails are already used in industry for the degradation of natural complex compounds, such as lignocellulose ( Lopes et al, 2018 ). Currently, projects are starting up researching the use of enzyme cocktails for plastic degradation ( Ballerstedt et al, 2021 ).…”