Project

MIX-UP: MIXed plastics biodegradation and UPcycling using microbial communities

Goal: Plastics are an important material in our economy, but there are serious downsides for the environment and our health. Plastic adversely affects all ecosystems and microplastics are of particular concern to our health. Increasing plastic waste recycling is a top priority in Europe’s transition towards a circular economy. The EU-funded MIX-UP project is addressing the market needs for new sustainable routes to valorise plastics waste streams. As such, plastic mixtures with five of the top six fossil-based recalcitrant plastics (PP, PE, PUR, PET and PS) and biodegradable plastics such as PLA and PHA, will be used as feedstock for microbial transformations. Not only will this increase the recycling quota, it will add value to poorly recycled plastic waste streams.

Date: 1 January 2020 - 31 December 2023

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Project log

Ren Wei
added an update
Check out the new MIX-UP publication "Sustainable cycloaliphatic  polyurethanes: from synthesis to applications" published in the journal Chemical Society Reviews. Congratulations to Agathe Mouren and Luc  Avérous to the success!
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Ren Wei
added an update
Prof. Lars Blank was a guest on "Auf den Punkt gebracht", a podcast from RWTH Aachen University.
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Ren Wei
added 2 research items
Poly(vinyl alcohol) (PVA) is a water‐soluble synthetic vinyl polymer with remarkable physical properties including thermostability and viscosity. Its biodegradability, however, is low even though a large amount of PVA is released into the environment. Established physical‐chemical degradation methods for PVA have several disadvantages such as high price, low efficiency, and secondary pollution. Biodegradation of PVA by microorganisms is slow and frequently involves pyrroloquinoline quinone (PQQ)‐dependent enzymes, making it expensive due to the costly cofactor and hence unattractive for industrial applications. In this study, we present a modified PVA film with improved properties as well as a PQQ‐independent novel enzymatic cascade for the degradation of modified and unmodified PVA. The cascade consists of four steps catalyzed by three enzymes with in situ cofactor recycling technology making this cascade suitable for industrial applications.
Poly(vinyl alcohol) (PVA) is a water‐soluble synthetic vinyl polymer with remarkable physical properties including thermostability and viscosity. Its biodegradability, however, is low even though a large amount of PVA is released into the environment. Established physical‐chemical degradation methods for PVA have several disadvantages such as high price, low efficiency, and secondary pollution. Biodegradation of PVA by microorganisms is slow and frequently involves pyrroloquinoline quinone (PQQ)‐dependent enzymes, making it expensive due to the costly cofactor and hence unattractive for industrial applications. In this study, we present a modified PVA film with improved properties as well as a PQQ‐independent novel enzymatic cascade for the degradation of modified and unmodified PVA. The cascade consists of four steps catalyzed by three enzymes with in situ cofactor recycling technology making this cascade suitable for industrial applications.
Ren Wei
added a research item
Microorganisms capable of decomposing polyurethane (PU) and other plastics have the potential to be used in bio-recycling processes. In this study, 20 PU-degrading strains were isolated, including 11 bacteria and 9 fungi, using a synthesized poly(1,4-butylene adipate)-based PU (PBA-PU) as the screening substrate. Three PU substrates with increasing structure complexities were used for a thorough evaluation of microbial degradation capacity: Impranil® DLN-SD, PBA-PU film and PU foam waste. After 4 days, the best fungal PBA-PU degrader, Cladosporium sp. P7, could degrade 94.5% of Impranil® DLN-SD. After 28 days of cultivation, 32.42% and 43.91% of solid PBA-PU film was converted into soluble small molecules when used as the sole carbon source or in a medium with other co-carbon sources, respectively. Accordingly, the weight loss of PU foam waste after 15 days was 15.3% for the sole carbon condition and 83.83% for the co-carbon conditions. Furthermore, PBA-PU was used for metabolic pathway analysis because of its known composition and chemical structure. Six metabolites were identified during the degradation process of PBA-PU, including adipic acid (AA), 1,4-butanediol (BDO), and 4,4'-methylenedianiline (MDA), which can also be used as the sole carbon source to grow the fungal strain P7, resulting in the discovery of two MDA metabolites during the cultivation processes. Based on the presence of these eight metabolites, we hypothesized that PBA-PU is first depolymerized by the fungal strain P7 via ester and urethane bond hydrolysis, followed by intracellular metabolism and mineralization of the three monomers to CO2 and H2O.
Ren Wei
added an update
Parents and caregivers want to provide children with the best possible toys that will spark their imagination and help them learn and grow. However, with the increasing awareness of environmental issues, it's important to also consider the impact of the toys we choose on the planet. Sustainable toy options are a great way to ensure that our children have fun while also reducing our carbon footprint.
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Ren Wei
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Are you interested in joining MIX-UP? Postdoctoral position at the University of Strasbourg for 12 months with a focus on polymer chemical synthesis and characterization of renewable polymers available.
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Ren Wei
added 2 research items
Enzymatic hydrolysis holds great promise for plastic waste recycling and upcycling. The interfacial catalysis mode, and the variability of polymer specimen properties under different degradation conditions, add to the complexity and difficulty of understanding polymer cleavage and engineering better biocatalysts. We present a systemic approach to studying the enzyme-catalyzed surface erosion of poly(ethylene terephthalate) (PET) while monitoring/controlling operating conditions in real time with simultaneous detection of mass loss and changes in viscoelastic behavior. PET nanofilms placed on water showed a porous morphology and a thickness-dependent glass transition temperature (Tg) between 40°C and 44°C, which is >20°C lower than the Tg of bulk amorphous PET. Hydrolysis by a dual-enzyme system containing thermostabilized variants of Ideonella sakaiensis PETase and MHETase resulted in a maximum depolymerization of 70% in 1 h at 50°C. We demonstrate that increased accessible surface area, amorphization, and Tg reduction speed up PET degradation while simultaneously lowering the threshold for degradation-induced crystallization.
TfCa, a promiscuous carboxylesterase from Thermobifida fusca, was found to hydrolyze polyethylene terephthalate (PET) degradation intermediates such as bis(2-hydroxyethyl) terephthalate (BHET) and mono-(2-hydroxyethyl)-terephthalate (MHET). In this study, we elucidated the structures of TfCa in its apo form, as well as in complex with a PET monomer analogue and with BHET. The structure–function relationship of TfCa was investigated by comparing its hydrolytic activity on various ortho- and para-phthalate esters of different lengths. Structure-guided rational engineering of amino acid residues in the substrate-binding pocket resulted in the TfCa variant I69W/V376A (WA), which showed 2.6-fold and 3.3-fold higher hydrolytic activity on MHET and BHET, respectively, than the wild-type enzyme. TfCa or its WA variant was mixed with a mesophilic PET depolymerizing enzyme variant [Ideonella sakaiensis PETase (IsPETase) PM] to degrade PET substrates of various crystallinity. The dual enzyme system with the wild-type TfCa or its WA variant produced up to 11-fold and 14-fold more terephthalate (TPA) than the single IsPETase PM, respectively. In comparison to the recently published chimeric fusion protein of IsPETase and MHETase, our system requires 10% IsPETase and one-fourth of the reaction time to yield the same amount of TPA under similar PET degradation conditions. Our simple dual enzyme system reveals further advantages in terms of cost-effectiveness and catalytic efficiency since it does not require time-consuming and expensive cross-linking and immobilization approaches.
Ren Wei
added an update
Check out the new MIX-UP publication "Rapid depolymerization of poly(ethylene terephthalate) thin films by a dual-enzyme system and its impact on material properties" published in the journal Chem Catalysis. Congratulations to Natalia A. Tarazona, Ren Wei, Stefan Brott, Lara Pfaff, Uwe T. Bornscheuer, Andreas Lendlein, and Rainhard Machatschek to the success!
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Ren Wei
added an update
New article "Structural Insights into (Tere)phthalate-Ester Hydrolysis by a Carboxylesterase and Its Role in Promoting PET Depolymerization" published in the journal ACS Catalysis. Congratulations to our MIX-UP partners and their colleagues Gerlis von Haugwitz, Xu Han, Lara Pfaff, Qian Li, Hongli Wei, Jian Gao, Karen Methling, Yufei Ao, Yannik Brack, Jan Mican, Christian G. Feiler, Manfred S. Weiss, David Bednar, Gottfried J. Palm, Michael Lalk, Michael Lammers, Jiri Damborsky, Gert Weber, Weidong Liu, Uwe T. Bornscheuer and Ren Wei to these great results!
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Ren Wei
added an update
On December 7th & 8th a special symposium addressing the scientific advances in the fields of enzymatic recycling of plastic was held in Paris.
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Ren Wei
added an update
Are you struggling to be sustainable over the holidays? No matter if you are trying to reduce waste or just want to get creative over the holiday season, we have compiled a few tips to help you make your Christmas more environmentally friendly this year.
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Ren Wei
added an update
The Great Bubble Barrier protects critical ecosystems by generating a bubble curtain along canals and rivers that blocks plastics from entering the sea. Their smart solution to plastic pollution was now recognized with the Earthshot Prize.
 
Ren Wei
added an update
Plastic is everywhere. Plastic pollution has significant environmental, health, social, and economic impacts. The rapidly increasing levels of plastic pollution, including microplastics, present a serious transboundary environmental problem. beworm, a German startup, uses organisms that eat plastic to solve this problem.
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Ren Wei
added an update
Enzymes that rapidly degrade plastic bags have been discovered in the saliva of waxworms' moth larvae that infest hives. They are the first enzymes to degrade polyethylene within hours at room temperature, and they could lead to cost-effective methods for recycling plastic.
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Ren Wei
added an update
Recycling is great, but unfortunately, global recycling rates are still too low. How can we achieve more efficient recycling and what are the challenges facing the recycling industry? A new publication gives us hope for a simpler and more efficient recycling process.
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Ren Wei
added an update
New article "Depolymerization of post-consumer PET bottles with engineered cutinase 1 from Thermobifida cellulosilytica" was published in the journal Green chemistry. Congratulations to our MIX-UP partners and their colleagues Zixuan Zhang, Shiming Huang, Di Cai, Chaofeng Shao, Changwei Zhang, Junhui Zhou, Ziheng Cui, Tianqi He, Changjing Chen, Biqiang Chen and Tianwei Tan for these great results!
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Ren Wei
added an update
German Federal Environment Minister Steffi Lemke wants to implement this idea: If plastic waste ends up in parks and on roads, manufacturers should also pay for its disposal.
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Ren Wei
added an update
Check out the new MIX-UP publication "Flexibility Regulation of Loops Surrounding the Tunnel Entrance in Cytochrome P450 Enhanced Substrate Access Substantially" published in the journal ACS Catalysis. Congratulations to our partners Zhongyu Li, Shuaiqi Meng, Kaili Nie, Ulrich Schwaneberg, Mehdi D. Davari, Haijun Xu, Yu Ji, and Luo Liu for the success!
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Ren Wei
added an update
iAMB presented two talks and six posters at Biosurfactants 2022 international conference. Link https://www.mix-up.eu/news/detail/biosurfactants-2022-international-conference
 
Ren Wei
added an update
Lars Blank comments on the challange constituted by unfavorable plastic combinations in our food packaging.
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Ren Wei
added an update
Microplastics can be found everywhere. These tiny plastic particles pollute almost every ecosystem on earth. The oceans are particularly affected and maritime trenches thousands of meters below sea level are the "final resting place" for a larger amount of the smallest plastic particles than expected.
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Ren Wei
added an update
Successful meeting in Strasbourg and via Zoom.
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Ren Wei
added an update
Those who think sustainably usually prefer reusable bottles. Since they can be used several times, they are considered to be more environmentally friendly. This is especially true for glass bottles. Those are not made from petroleum and can be cleaned more often. But are plastic bottles really less sustainable?
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Ren Wei
added an update
Check out the new MIX-UP publication "Multiple Substrate Binding Mode-Guided Engineering of a Thermophilic PET Hydrolase" published in the Journal ACS Catalysis. Congratulations to our partners Lara Pfaff, Jian Gao, Zhishuai Li, Anna Jäckering, Gert Weber, Jan Mican, Yinping Chen, Weiliang Dong, Xu Han, Christian G. Feiler, Yu-Fei Ao, Christoffel P. S. Badenhorst, David Bednar, Gottfried J. Palm, Michael Lammers, Jiri Damborsky, Birgit Strodel, Weidong Liu, Uwe T. Bornscheuer and Ren Wei to the success!
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Ren Wei
added an update
The new article "Molecular and Biochemical Differences of the Tandem and Cold-Adapted PET Hydrolases Ple628 and Ple629, Isolated From a Marine Microbial Consortium" was published in the journal Frontiers in Bioengineering and Biotechnology. Congratulations to our MIX-UP partners and their colleagues Ingrid E. Meyer Cifuentes, Pan Wu, Yipei Zhao, Weidong Liu, Meina Neumann-Schaal, Lara Pfaff, Justyna Barys, Zhishuai Li, Jian Gao, Xu Han, Uwe T. Bornscheuer, Ren Wei and Başak Öztürk to these great results!
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Ren Wei
added an update
Check out the new MIX-UP publication "Feasible Cluster Model Method for Simulating the Redox Potentials of Laccase CueO and Its Variant" published in the Journal Frontiers in Bioengineering and Biotechnology. Congratulations to our partners Qixuan Jiang, Ziheng Cui, Ren Wei, Kaili Nie, Haijun Xu, and Luo Liu for their success!
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Ren Wei
added an update
The new article "Application of a novel fluorogenic polyurethane analogue probe in polyester-degrading microorganisms screening by microfluidic droplet" was published in the journal Microbial Biotechnology. Congratulations to our MIX-UP partners and their colleagues Anming Xu, Jiawei Liu, Shixiang Cao, Bin Xu, Chengzhi Guo, Ziyi Yu, Xiaoqiang Chen, Jie Zhou, Weiliang Dong, and Min Jiang for these great results!
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Ren Wei
added a research item
Thermophilic polyester hydrolases (PES-H) have recently enabled biocatalytic recycling of the mass-produced synthetic polyester polyethylene terephthalate (PET), which has found widespread use in the packaging and textile industries. The growing demand for efficient PET hydrolases prompted us to solve high-resolution crystal structures of two metagenome-derived enzymes (PES-H1 and PES-H2) and notably also in complex with various PET substrate analogues. Structural analyses and computational modeling using molecular dynamics simulations provided an understanding of how product inhibition and multiple substrate binding modes influence key mechanistic steps of enzymatic PET hydrolysis. Key residues involved in substrate-binding and those identified previously as mutational hotspots in homologous enzymes were subjected to mutagenesis. At 72 °C, the L92F/Q94Y variant of PES-H1 exhibited 2.3-fold and 3.4-fold improved hydrolytic activity against amorphous PET films and pretreated real-world PET waste, respectively. The R204C/S250C variant of PES-H1 had a 6.4 °C higher melting temperature than the wild-type enzyme but retained similar hydrolytic activity. Under optimal reaction conditions, the L92F/Q94Y variant of PES-H1 hydrolyzed low-crystallinity PET materials 2.2-fold more efficiently than LCC ICCG, which was previously the most active PET hydrolase reported in the literature. This property makes the L92F/Q94Y variant of PES-H1 a good candidate for future applications in industrial plastic recycling processes.
Ren Wei
added 2 research items
Laccases are regarded as versatile green biocatalysts, and recent scientific research has focused on improving their redox potential for broader industrial and environmental applications. The density functional theory (DFT) quantum mechanics approach, sufficiently rigorous and efficient for the calculation of electronic structures, is conducted to better comprehend the connection between the redox potential and the atomic structural feature of laccases. According to the crystal structure of wild type laccase CueO and its variant, a truncated miniature cluster model method was established in this research. On the basic of thermodynamic cycle, the overall Gibbs free energy variations before and after the one-electron reduction were calculated. It turned out that the trends of redox potentials to increase after variant predicted by the theoretical calculations correlated well with those obtained by experiments, thereby validating the feasibility of this cluster model method for simulating the redox potentials of laccases.
Polybutylene adipate terephthalate (PBAT) is a biodegradable alternative to polyethylene and can be broadly used in various applications. These polymers can be degraded by hydrolases of terrestrial and aquatic origin. In a previous study, we identified tandem PETase-like hydrolases (Ples) from the marine microbial consortium I1 that were highly expressed when a PBAT blend was supplied as the only carbon source. In this study, the tandem Ples, Ple628 and Ple629, were recombinantly expressed and characterized. Both enzymes are mesophilic and active on a wide range of oligomers. The activities of the Ples differed greatly when model substrates, PBAT-modified polymers or PET nanoparticles were supplied. Ple629 was always more active than Ple628. Crystal structures of Ple628 and Ple629 revealed a structural similarity to other PETases and can be classified as member of the PETases IIa subclass, α/β hydrolase superfamily. Our results show that the predicted functions of Ple628 and Ple629 agree with the bioinformatic predictions, and these enzymes play a significant role in the plastic degradation by the consortium.
Ren Wei
added an update
The EFB Biocatalysis Division and the EFB Biobased Materials Division were invited to Biocatalysis for the Biological Transformation of Polymer Science conference.
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Ren Wei
added an update
The new article "Transcription-Associated Fluorescence-Activated Droplet Sorting for Di-rhamnolipid Hyperproducers" was published in the journal ACS Synthetic Biology. Congratulations to our MIX-UP partners and their colleagues Anming Xu, Xiaoxiao Zhang, Shixiang Cao, Xiaoli Zhou, Ziyi Yu, Xiujuan Qian, Jie Zhou, Weiliang Dong, and Min Jiang for these great results!
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Ren Wei
added an update
Check out the new MIX-UP publication "Construction and comparison of synthetic microbial consortium system (SMCs) by non-living or living materials immobilization and application in acetochlor degradation" published in the Journal of Hazardous Materials. Congratulations to our partners Jingyuan Liu, Xiaoli Zhou, Tong Wang, Lingling Fan, Shixun Liu, Nan Wu, Anming Xu, Xiujuan Qian, Zhoukun Li, Min Jiang, Jie Zhou, and Weiliang Dong for the success!
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Ren Wei
added an update
The new article "Biodegradation of polyether-polyurethane foam in yellow mealworms (Tenebrio molitor) and effects on the gut microbiome" was published in the journal Chemosphere. Congratulations to our MIX-UP partners and their colleagues Jiawei Liu, Jingyuan Liu, Bin Xu, Anming Xu, Shixiang Cao, Ren Wei, Jie Zhou, Min Jiang, and Weiliang Dong for these excellent results!
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Ren Wei
added an update
The RWTH Aachen University presents an exhibition of current reseach in the field of sustainability.
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Ren Wei
added a research item
Polyurethane (PU) is one of the mass-produced recalcitrant plastics with a high environmental resistance but extremely low biodegradability. Therefore, improperly disposed PU waste adds significantly to plastic pollution, which must be addressed immediately. In recent years, there has been an increasing number of reports on plastic biodegradation in insect larvae, especially those that can feed on polyethylene and polystyrene. This study revealed that yellow mealworm (Tenebrio molitor) larvae can chew and ingest polyether-PU foams efficiently, resulting in a significant mass loss of nearly 67% after 35 days at a similar survival rate compared to when fed on bran. However, polyether-PU fragments were found in the frass of T. molitor, indicating that polyether-PU biodegradation and bioconversion in intestinal tracts were not complete. The scission of ether and urethane bonds in the polyether-PU can be evidenced by comparing polymer fragments recovered from frass with the pristine ones using Fourier transform infrared spectroscopy and X-ray photoelectron spectroscopy. Gel permeation chromatography suggested the release of low-molecular-weight oligomers as a result of the biodegradation, which also resulted in poor thermal stability of the polyether-PU foam as determined by thermogravimetric analysis. High-throughput sequencing of the gut microbiome revealed significant changes in the microbial community populations due to the polyether-PU diet, for example, an increase in the families Enterobacteriaceae and Streptococcaceae, suggesting that these microorganisms may contribute to the polyether-PU biodegradation.
Ren Wei
added a research item
Plastic waste imposes a serious problem to the environment and society. Hence, strategies for a circular plastic economy are demanded. One strategy is the engineering of polyester hydrolases towards higher activity for the biotechnological recycling of polyethylene terephthalate (PET). To provide tools for the rapid characterization of PET hydrolases and the detection of degradation products like terephthalic acid (TPA), we coupled a carboxylic acid reductase (CAR) and the luciferase LuxAB. CAR converted TPA into the corresponding aldehydes in Escherichia coli, which yielded bioluminescence that not only semi-quantitatively reflected amounts of TPA in hydrolysis samples but is suitable as a high-throughput screening assay to assess PET hydrolase activity. Furthermore, the CAR-catalyzed synthesis of terephthalaldehyde was combined with a reductive amination cascade in a one-pot set-up yielding the corresponding diamine, suggesting a new strategy for the transformation of TPA as a product obtained from PET biodegradation.
Ren Wei
added an update
Check out the new MIX-UP publication "Biosensor and chemo-enzymatic one-pot cascade applications to detect and transform PET-derived terephthalic acid in living cells" published in the journal iScience. Congratulations to our partners Thomas Bayer, Lara Pfaff, Yannick Branson, Aileen Becker, Shuke Wu, Uwe T. Bornscheuer and Ren Wei to the success!
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Ren Wei
added an update
Ren Wei
added an update
Get to know the future-oriented world of European projects from NRW.
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Ren Wei
added an update
A new article "Process analysis of microplastic degradation using activated PMS and Fenton reagents" was published in the journal Chemosphere. Congratulations to our MIX-UP partners and their colleagues Bin Liu, Qixuan Jiang, Zenghui Qiu, Luo Liu, Ren Wei, Xin Zhang, and Haijun Xu for these great results!
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Ren Wei
added an update
Scientists from around the world will come together to help tackle the global plastic pollution crisis at the first annual World Plastic Summit in Monaco.
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Ren Wei
added a research item
The environmental degradation and physical aging of microplastics (MP) caused by oxidative stress have not been thoroughly elucidated. In this study, we used different oxidative agents (Fe²⁺-activated peroxymonosulfate and Fenton reagents) that can form free radicals to study the degradation mechanisms of nylon 6 (PA6) and polystyrene (PS) MPs. After 4 cycles of treatment, mass losses of 25.6% and 22.1% were obtained with PA6 and PS MPs, respectively. Scanning electron microscopy (SEM), Fourier-transform infrared (FTIR) spectroscopy, Raman spectroscopy, and X-ray photoelectron spectroscopy (XPS) were employed to confirm the MP oxidation, and polymer chain scissions. FTIR data indicated the existence of oxygen-containing chemical groups resulting from MPs oxidation, and chain scissions, such as CO, C–O, and O–CO. Raman spectroscopy suggested the presence of exposed aromatic groups, and weakening of the relative intensity of C–H related to the oxidation, and chain scission of the MPs. SEM imaging revealed visible morphological changes on the surface of MPs as a result of degradation. XPS indicated that the O/C ratio could be used as an indicator for the degree of MPs oxidation. By analyzing the degradation products with surface-enhanced Raman scattering (SERS) and gas chromatography-mass spectrometry, low-molecular-weight alkanes, alcohols, aldehydes, carboxylic acids derived from the derivatization of alcohols, were detected. These findings confirmed the advantage of using multiple analytic methods in tandem to evaluate the degradation of environmental MPs.
Ren Wei
added an update
Check out the new MIX-UP publication "Mechanism-Based Design of Efficient PET Hydrolases " published in the journal ACS Catalysis. Congratulations to our partners Ren Wei, Gerlis von Haugwitz, Lara Pfaff, Jan Mican, Christoffel P. S. Badenhorst, Weidong Liu, Gert Weber, Harry P. Austin, David Bednar, Jiri Damborsky and Uwe T. Bornscheuer to the success!
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Ren Wei
added an update
A historic week is behind us. The UN Environment Assembly has agreed to a treaty elaboration that could effectively fight the plastic problem. An overview and report of an assembly in which we too have placed a lot of hope.
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Ren Wei
added a research item
Polyethylene terephthalate (PET) is the most widespread synthetic polyester, having been utilized in textile fibers and packaging materials for beverages and food, contributing considerably to the global solid waste stream and environmental plastic pollution. While enzymatic PET recycling and upcycling have recently emerged as viable disposal methods for a circular plastic economy, only a handful of benchmark enzymes have been thoroughly described and subjected to protein engineering for improved properties over the last 16 years. By analyzing the specific material properties of PET and the reaction mechanisms in the context of interfacial biocatalysis, this Perspective identifies several limitations in current enzymatic PET degradation approaches. Unbalanced enzyme−substrate interactions, limited thermostability, and low catalytic efficiency at elevated reaction temperatures, and inhibition caused by oligomeric degradation intermediates still hamper industrial applications that require high catalytic efficiency. To overcome these limitations, successful protein engineering studies using innovative experimental and computational approaches have been published extensively in recent years in this thriving research field and are summarized and discussed in detail here. The acquired knowledge and experience will be applied in the near future to address plastic waste contributed by other mass-produced polymer types (e.g., polyamides and polyurethanes) that should also be properly disposed by biotechnological approaches.
Ren Wei
added an update
Chemicals in the environment have long been considered minor. Now, for the first time, researchers have defined how many chemicals the earth can handle before the global ecosystem collapses. The finding: chemicals are much more dangerous than long thought. Action is now immediately urgent.
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Ren Wei
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4th General Assembly & 2nd Technical Review for MIX-UP
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Ren Wei
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New article "Nano-immobilization of PETase enzyme for enhanced  polyethylene terephthalate biodegradation" was published in the journal  Biochemical Engineering. Congratulations to our MIX-UP partners and their colleagues Yunpu Jia, Nadia A.Samak, Xuemi Hao, Zheng Chen, Gama  Yang, Xuhao Zhao, Tingzhen Mu, Maohua Yang, and Jianmin Xing to these  great results!
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Ren Wei
added an update
Oatmeal for 80 cents, yogurt for 1.50 euros, 500 grams of meat for 2.99 - these may be the costs for you. Yet much of it is literally at the expense of the environment. If we consumers paid for the environmental damage, prices would be much higher. Why is that?
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Ren Wei
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Check out the new MIX-UP publication "Synthetic Control of Metabolic States in Pseudomonas putida by Tuning Polyhydroxyalkanoate Cycle" published in the journal mBio. Congratulations to our partners Maria-Tsampika Manoli, Juan Nogales and Auxiliadora Prieto for the success!
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Ren Wei
added an update
New article "Automated design and implementation of a NOR gate in  Pseudomonas putida" was published in the journal Synthetic Biology.  Congratulations to our MIX-UP partners and their colleagues Huseyin Tas,  Lewis Grozinger, Angel Goñi-Moreno, and Victor de Lorenzo on these great results!
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Ren Wei
added an update
Check out the new MIX-UP publication "ssDNA recombineering boosts in vivo evolution of nanobodies displayed on bacterial surfaces" published in the journal Communications Biology. Congratulations to our partners  Yamal Al-ramahi, Akos Nyerges, Yago Margolles, Lidia Cerdán, Gyorgyi  Ferenc, Csaba Pál, Luis Ángel Fernández and Víctor de Lorenzo to the  success!
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Ren Wei
added an update
New article "Standardization of inducer-activated broad host range expression modules: Debugging and refactoring an alkane-responsive AlkS/PalkB device" was published in the journal Synthetic Biology. Congratulations to our MIX-UP partners and their colleagues Alejandro Arce-Rodríguez, Ilaria Benedetti, José Manuel Borrero-de Acuña, Rafael Silva-Rocha and Víctor de Lorenzo to these great results!
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Ren Wei
added an update
Check out the new MIX-UP publication "Fusion of Chitin-Binding Domain From Chitinolyticbacter meiyuanensis SYBC-H1 to the Leaf-Branch Compost Cutinase for Enhanced PET Hydrolysis" published in Frontiers in Bioengineering and Biotechnology. Congratulations to our partners Rui Xue, Yinping Chen, Huan Rong, Ren Wei, Zhongli Cui, Jie Zhou, Weiliang Dong and Min Jiang for the success!
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Ren Wei
added an update
New article "Engineering and evaluation of thermostable IsPETase variants for PET degradation" published in the journal Engineering in Life Sciences. Congratulations to our MIX-UP partners and their colleagues Stefan Brott, Lara Pfaff, Josephine Schuricht, Jan-Niklas Schwarz, Dominique Böttcher, Christoffel P. S. Badenhorst, Ren Wei, Uwe T. Bornscheuer to these great results!
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Ren Wei
added a research item
The plastic crisis requires drastic measures, especially for the plastics’ end-of-life. Mixed plastic fractions are currently difficult to recycle, but microbial metabolism might open new pathways. With new technologies for degradation of plastics to oligo- and monomers, these carbon sources can be used in biotechnology for the upcycling of plastic waste to valuable products, such as bioplastics and biosurfactants. We briefly summarize well-known monomer degradation pathways and computed their theoretical yields for industrially interesting products. With this information in hand, we calculated replacement scenarios of existing fossil-based synthesis routes for the same products. Thereby, we highlight fossil-based products for which plastic monomers might be attractive alternative carbon sources. Notably, not the highest yield of product on substrate of the biochemical route, but rather the (in-)efficiency of the petrochemical routes (i.e., carbon, energy use) determines the potential of biochemical plastic upcycling. Our results might serve as a guide for future metabolic engineering efforts towards a sustainable plastic economy.
Ren Wei
added 2 research items
Polyethylene terephthalate (PET) is a mass-produced petroleum-based synthetic polymer. Enzymatic PET degradation using, for example, Ideonella sakaiensis PETase (IsPETase) can be a more environmentally friendly and energy-saving alternative to the chemical recycling of PET. However, IsPETase is a mesophilic enzyme with an optimal reaction temperature lower than the glass transition temperature (Tg) of PET, where the amorphous polymers can be readily accessed for enzymatic breakdown. In this study, we used error-prone PCR to generate a mutant library based on a thermostable triple mutant (TM) of IsPETase. The library was screened against the commercially available polyester-polyurethane Impranil DLN W 50 for more thermostable IsPETase variants, yielding four variants with higher melting points. The most promising IsPETaseTMK95N/F201I variant had a 5.0°C higher melting point than IsPETaseTM. Although this variant showed a slightly lower activity on PET at lower incubation temperatures, its increased thermostability makes it a more active PET hydrolase at higher reaction temperatures up to 60°C. Several other variants were compared and combined with selected previously published IsPETase mutants in terms of thermostability and hydrolytic activity against PET nanoparticles and amorphous PET films. Our findings indicate that thermostability is one of the most important characteristics of an effective PET hydrolase.
Polyethylene terephthalate (PET) is a mass-produced petroleum-based non-biodegradable plastic that contributes to the global plastic pollution. Recently, biocatalytic degradation has emerged as a viable recycling approach for PET waste, especially with thermophilic polyester hydrolases such as a cutinase (LCC) isolated from a leaf-branch compost metagenome and its variants. To improve the enzymatic PET hydrolysis performance, we fused a chitin-binding domain (ChBD) from Chitinolyticbacter meiyuanensis SYBC-H1 to the C-terminus of the previously reported LCC ICCG variant, demonstrating higher adsorption to PET substrates and, as a result, improved degradation performance by up to 19.6% compared to with its precursor enzyme without the binding module. For compare hydrolysis with different binding module, the catalytic activity of LCC ICCG -ChBD, LCC ICCG -CBM, LCC ICCG -PBM and LCC ICCG -HFB4 were further investigated with PET substrates of various crystallinity and it showed measurable activity on high crystalline PET with 40% crystallinity. These results indicated that fusing a polymer-binding module to LCC ICCG is a promising method stimulating the enzymatic hydrolysis of PET.
Ren Wei
added an update
Join the international Seminar on Biotechnology Applied to the Plastics Sector organized by AIMPLAS.
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Ren Wei
added an update
Check out the new MIX-UP publication "A pseudo-homogeneous system for PET glycolysis using a colloidal catalyst of graphite carbon nitride in ethylene glycol" published in Polymer Degradation and Stability. Congratulations to our partners Zishuai Wang, Yaoqiang Wang, Shengnan Xu, Yu Jin, Zequn Tang, Gang Xiao, Haijia Su for the success!
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Ren Wei
added an update
New article "When microbial biotechnology meets material engineering" was published in the Journal Microbial Biotechnology. Congratulations to our MIX-UP partners and their colleagues Ana M. Hernandez-Arriaga, Cristina Campano, Virginia Rivero-Buceta, and M. Auxiliadora Prieto to these were great results!
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Ren Wei
added an update
Hardly any other place uses as much disposable plastic as hospitals. In the corona pandemic, consumption has - justifiably - risen sharply. But there are solutions - they just have to be taken into consideration.
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Ren Wei
added an update
The European Alliance for plastics recycling activates public and private actors for the transition from linear to circular value chains.
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Ren Wei
added an update
everwave wins KfW Award Gründen NRW. Congratulations!
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Ren Wei
added an update
Check out the new MIX-UP publication "Quantum Mechanical Investigation of the Oxidative Cleavage of the C–C Backbone Bonds in Polyethylene Model Molecules" published in Polymers. Congratulations to our partners from BUCT and the University of Greifswald for the successful cooperation!
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Ren Wei
added an update
Bioeconomy innovations in the German pavilion.
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Ren Wei
added an update
Bioeconomy: The Green Revolution - check out what our project partner Nick Wierckx from FZJ thinks about bioeconomy and gain insights into his lab work in the new ARTE documentary!
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Ren Wei
added an update
The Corona pandemic has been quite a disruption to the most MIX-UP scientist's research. Labs were closed, trips were cancelled. Now we asked the PhD students about their experiences over the past one and a half years - and learned some amazing things: Can the pandemic also have advantages?
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Ren Wei
added an update
Last Saturday, the International Clean Up Day took place. Scientists from MIX-UP and volunteers from everwave and the PAN Aachen network cleaned up some places in the German cities Aachen and Dortmund and the Dutch region of South Limburg - and pulled some strange things out of the bushes. But see for yourself.
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Ren Wei
added an update
A few months ago, our partner everwave started collecting plastic waste from the Danube in Serbia. Now the waste has a new purpose: MIX-UP scientists are examining the waste in the laboratory. What exactly are they trying to find out?
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Ren Wei
added an update
Great news from our MIX-UP partner RWTH-AVT! AVT joins the European database Pilots4u with their NGP2 Biorefinery.
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Ren Wei
added an update
Renewable resources, quality processing, fair wages - sustainable products often appear expensive at first glance. Only a minority is still prepared to pay a noticeably higher price. Yet, on balance, they are not necessarily more expensive in relation to their lifespan. Read here why.
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Ren Wei
added an update
Cows are considered major polluters. But a study now shows that enzymes from their stomachs can help break down plastic. How it came about and what exactly the scientists found out.
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Ren Wei
added a research item
This article introduces the EU Horizon 2020 research project MIX-UP, "Mixed plastics biodegradation and upcycling using microbial communities". The project focuses on changing the traditional linear value chain of plastics to a sustainable, biodegradable based one. Plastic mixtures contain five of the top six fossil-based recalcitrant plastics [polyethylene (PE), polyurethane (PUR), polypropylene (PP), polyethylene terephthalate (PET), polystyrene (PS)], along with upcoming bioplastics polyhydroxyalkanoate (PHA) and polylactate (PLA) will be used as feedstock for microbial transformations. Consecutive controlled enzymatic and microbial degradation of mechanically pre-treated plastics wastes combined with subsequent microbial conversion to polymers and value-added chemicals by mixed cultures. Known plastic-degrading enzymes will be optimised by integrated protein engineering to achieve high specific binding capacities, stability, and catalytic efficacy towards a broad spectrum of plastic polymers under high salt and temperature conditions. Another focus lies in the search and isolation of novel enzymes active on recalcitrant polymers. MIX-UP will formulate enzyme cocktails tailored to specific waste streams and strives to enhance enzyme production significantly. In vivo and in vitro application of these cocktails enable stable, self-sustaining microbiomes to convert the released plastic monomers selectively into value-added products, key building blocks, and biomass. Any remaining material recalcitrant to the enzymatic activities will be recirculated into the process by physicochemical treatment. The Chinese–European MIX-UP consortium is multidisciplinary and industry-participating to address the market need for novel sustainable routes to valorise plastic waste streams. The project's new workflow realises a circular (bio)plastic economy and adds value to present poorly recycled plastic wastes where mechanical and chemical plastic recycling show limits.
Ren Wei
added an update
Our partner everwave is usually on the road in faraway countries to free waters from plastic waste. But then came the floods in Germany, and everwave was suddenly in the thick of it. Read here how our MIX-UP partner was able to help in the hard-hit areas.
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Ren Wei
added a research item
Recalcitrant plastic waste has caused serious global ecological problems. There is an urgent need to develop environmentally friendly and efficient methods for degrading the highly stable carbon skeleton structure of plastics. To that end, we used a quantum mechanical calculation to thoroughly investigate the oxidative scission of the carbon-carbon (C–C) backbone in polyethylene (PE). Here, we studied the reaction path of C–C bond oxidation via hydroxyl radical in PE. The flexible force constants and fuzzy bond orders of the C–C bonds were calculated in the presence of one or more carbocations in the same PE carbon chain. By comparison, the strength of the C–C bond decreased when carbocation density increased. However, the higher the density of carbocations, the higher the total energy of the molecule and the more difficult it was to be generated. The results revealed that PE oxidized to alcohol and other products, such as carboxylic acid, aldehyde and ketone, etc. Moreover, the presence of carbocations was seen to promote the cleavage of C–C backbones in the absence of oxygen.
Ren Wei
added an update
Check out the new MIX-UP publication "Engineering adipic acid metabolism in Pseudomonas putida" published in Metabolic Engineering. Congratulations to everyone involved!
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Ren Wei
added an update
Check out the article "Chemical and biological catalysis for plastics recycling and upcycling" by L.D. Ellis, N.A. Rorrer, K.P. Sullivan, M. Otto, J.E. McGeehan, Y. Román-Leshkov, N. Wierckx, and G.T. Beckham which was recently published in Nature Catalysis. Congratulations to our MIX-UP partners and their colleagues!
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Ren Wei
added an update
“The EU research project "ConCO2rde" is conducting research on one of the biggest environmental polluters of our time: carbon dioxide. The scientists are working on solutions on how to use the frowned upon CO2 in a sensible way. In an interview, project coordinator Sandy Schmidt explains how the scientists are proceeding.”
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Ren Wei
added an update
Check out the recent article "Reconfiguration of metabolic fluxes in Pseudomonas putida as a response to sub-lethal oxidative stress" published in The ISME Journal. Congratulations to our MIX-UP partners and their colleagues Pablo I. Nikel, Tobias Fuhrer, Max Chavarría, Alberto Sánchez-Pascuala, Uwe Sauer and Víctor de Lorenzo to these great results!
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Ren Wei
added an update
New publication within MIX-UP! Check out the article "Contextual dependencies expand the re-usability of genetic inverters" by Huseyin Tas, Lewis Grozinger, Ruud Stoof, Victor de Lorenzo, and Ángel Goñi-Moreno recently published in Nature Communications.
 
Guo-Qiang Chen
added a research item
Microbial polyhydroxyalkanoates (PHA) containing short- and medium/long-chain-length monomers, abbreviated as SCL-co-MCL/LCL PHAs, generate suitable thermal and mechanical properties. However, SCL-co-MCL/LCL PHAs with carbon chain longer than nine are difficult to synthesize due to the low specificity of PHA synthase PhaC and the lack of either SCL- or MCL/LCL monomer precursor fluxes. This study succeeds in reprogramming a β-oxidation weakened Pseudomonas entomophila containing synthesis pathways of SCL 3-hydroxybutyryl-CoA (3HB) from glucose and MCL/LCL 3-hydroxyalkanoyl-CoA from fatty acids with carbon chain lengths from 9 to 18, respectively, that are polymerized under a low specificity PhaC61-3 to form P(3HB-co-MCL/LCL 3HA) copolymers. Through rational flux-tuning approaches, the optimized recombinant P. entomophila accumulates 55 wt% poly-3-hydroxybutyrate in 8.4 g L⁻¹ cell dry weight. Combined with weakened β-oxidation, a series of novel P(3HB-co-MCL/LCL 3HA) copolymers with over 60 wt% PHA in 9 g L⁻¹ cell dry weight have been synthesized for the first time. P. entomophila has become a high-performing platform to generate tailor-made new SCL-co-MCL/LCL PHAs.
Ren Wei
added an update
New MIX-UP article "A Standardized Inverter Package Borne by Broad Host Range Plasmids for Genetic Circuit Design in Gram-Negative Bacteria" published in ACS Synthetic Biology. Congratulations to the authors Huseyin Tas, Ángel Goñi-Moreno, and Víctor de Lorenzo!
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Ren Wei
added an update
The worst of the Corona pandemic seems to be over. But only now is the collateral damage becoming apparent: for example, in the case of plastic. Consumption and thus pollution has increased dramatically.
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Ren Wei
added an update
New figures reveal: it is not just ten rivers as assumed that carry the majority of plastic into the oceans. The problem is much more complex. And raises new questions about the right counterstrategy.
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Ren Wei
added an update
Throw cardboard in the paper waste and wash used glass? For many, this sounds obvious, but it is often wrong. We list six misconceptions about waste separation and show how they can be avoided.
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Ren Wei
added an update
Over the past two days, we have again met virtually with more than 50 scientists for our bi-annual meeting and exchanged information on our research progress. This much can be revealed: despite all the online meetings and the more difficult conditions because of Corona, we are on a good path! Many Ph.D. students even reported that the pandemic has contributed to efficient work in some way - but more on that in one of our next blog posts in the coming weeks.
 
Ren Wei
added an update
The online magazine "Analytik News" published a new article about the recycling approach for phosphates which was newly developed at RWTH University by Ph.D. student Dr. Jonas Christ.
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Ren Wei
added an update
Check out the article published in the journal "Spektrum der Wissenschaft" by Tamara Worzewski. The well-written article thematizes the plastic life cycle and presents promising solution-oriented approaches which we also rely on in MIX-UP!
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Ren Wei
added an update
Single-use packaging has long been the subject of criticism. In some areas, such as medicine, they make total sense - in others, they don't. More and more countries are banning individual products with the hope that less plastic will end up in our environment. From July 3, a list of single-use plastic products will be banned in the EU.
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Ren Wei
added an update
'Waste is Simply a Valuable Resource in the Wrong Place' - These words belong to the Cradle to Cradle® concept, which opposes today's take-make-waste model and describes a model in which all materials are always kept in cycles – in a biological or technical one.
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Ren Wei
added an update
Sometimes in the Red Garbage Can, Sometimes in the Green Garbage Can: Too Much Plastic in Organic Waste. Far too often, diapers, can containers with food scraps, or just plain plastic end up in the organic waste garbage can. The problem was recently a topic of discussion in Germany, but it is likely to be on the agenda in many countries: People separate their waste too conscientiously.
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Ren Wei
added a research item
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.
Ren Wei
added an update
Recent publication within MIX-UP in Science of The Total Environment. Check out the interesting findings presented in the article "Enzymatic degradation of polyethylene terephthalate nanoplastics analyzed in real-time by isothermal titration calorimetry". Congratulations to all involved researchers!
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Ren Wei
added an update
Check out the recent publication within MIX-UP "Biocatalysis in the Recycling Landscape for Synthetic Polymers and Plastics towards Circular Textiles" published in the journal ChemSusChem. Congratulations to all researchers involved in this great success!
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Ren Wei
added an update
Biodegradable Plastics Have a Role to Play within a Circular Economy - This is the conclusion of the report ‘Biodegradability of plastics in the open environment’ from SAPEA – a Horizin2020 Project which is also part of the European Commission's Scientific Advice.
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Ren Wei
added an update
Recent research findings within MIX-UP published in "Trends in Biotechnology". The article explores the relevance of genome-editing tools like CRISPR/Cas for the improvement of PHA metabolic engineering. Congratulations to Xu Zhang, Yina Lin, Qiong Wu, Ying Wang, and Guo-Qiang Chen for this success!
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Ren Wei
added an update
Check out the recent article "Engineering Halomonas bluephagenesis for L-Threonine production" published in the journal Metabolic Engineering. Congratulations to all involved partners from China for these great results!
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Ren Wei
added an update
In January we took stock and a few weeks ago we received feedback from the European Commission. What does the feedback look like? Read it for yourself.
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Ren Wei
added an update
Recent publication within MIX-UP in the journal "Separation and Purification Technology". Congratulations to our Chinese partners involved!
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Ren Wei
added an update
Our partners Ren Wei from the University of Greifswald and Nick Wierckx from Forschungszentrum Jülich are involved together with Jun Yang from Beihang University Beijing as editors to the special issue on the research topic "Microbial Degradation of Plastics" which was recently published in Frontiers in Microbiology.
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