1
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Chen XQ, Rao DM, Zhu XY, Zhao XM, Huang QS, Wu J, Yan ZF. Current state and sustainable management of waste polyethylene terephthalate bio-disposal: enzymatic degradation to upcycling. BIORESOURCE TECHNOLOGY 2025; 429:132492. [PMID: 40209909 DOI: 10.1016/j.biortech.2025.132492] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/06/2025] [Revised: 03/28/2025] [Accepted: 04/05/2025] [Indexed: 04/12/2025]
Abstract
Poly (ethylene terephthalate) (PET) is a widely used plastic that leads to significant environmental pollution due to its durability. Enzymatic degradation of PET presents an eco-friendly disposal approach, with potential scalability for industrial applications. This review examines key crucial factors influencing PET enzymatic degradation, including the catalytic efficiency of PET hydrolase, production scalability of PET hydrolase, and recyclability of degraded PET. We outline major advancements in PET hydrolase development, including discovery techniques, functional enhancement strategies, and degradation optimization. Additionally, it assesses the preparation methodologies for PET hydrolase, covering bacterial expression systems, high-density fermentation technologies, and approaches for sustainable catalytic use. The review also discusses upcycling processes for PET hydrolysates, focusing on repolymerization into new plastics or bioconversion into valuable chemicals. Successful achievement of waste PET bio-disposal in industrial-scale n hinges on balancing degradation costs with revenue from upcycling products. Aim at this target, the review further points out the critical challenges, and proposes targeted solutions and expectations.
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Affiliation(s)
- Xiao-Qian Chen
- School of Biotechnology and Key Laboratory of Industrial Biotechnology Ministry of Education, Jiangnan University, 1800 Lihu Avenue, Wuxi 214122, China
| | - De-Ming Rao
- School of Life Science and Technology, Wuhan Polytechnic University, Wuhan 430023, China
| | - Xu-Yang Zhu
- School of Biotechnology and Key Laboratory of Industrial Biotechnology Ministry of Education, Jiangnan University, 1800 Lihu Avenue, Wuxi 214122, China
| | - Xiao-Min Zhao
- School of Biotechnology and Key Laboratory of Industrial Biotechnology Ministry of Education, Jiangnan University, 1800 Lihu Avenue, Wuxi 214122, China
| | - Qing-Song Huang
- School of Biotechnology and Key Laboratory of Industrial Biotechnology Ministry of Education, Jiangnan University, 1800 Lihu Avenue, Wuxi 214122, China
| | - Jing Wu
- School of Biotechnology and Key Laboratory of Industrial Biotechnology Ministry of Education, Jiangnan University, 1800 Lihu Avenue, Wuxi 214122, China
| | - Zheng-Fei Yan
- School of Biotechnology and Key Laboratory of Industrial Biotechnology Ministry of Education, Jiangnan University, 1800 Lihu Avenue, Wuxi 214122, China.
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2
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Weldon M, Ganguly S, Euler C. Co-consumption for plastics upcycling: A perspective. Metab Eng Commun 2025; 20:e00253. [PMID: 39802937 PMCID: PMC11717657 DOI: 10.1016/j.mec.2024.e00253] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2024] [Revised: 09/21/2024] [Accepted: 11/18/2024] [Indexed: 01/16/2025] Open
Abstract
The growing plastics end-of-life crisis threatens ecosystems and human health globally. Microbial plastic degradation and upcycling have emerged as potential solutions to this complex challenge, but their industrial feasibility and limitations thereon have not been fully characterized. In this perspective paper, we review literature describing both plastic degradation and transformation of plastic monomers into value-added products by microbes. We aim to understand the current feasibility of combining these into a single, closed-loop process. Our analysis shows that microbial plastic degradation is currently the rate-limiting step to "closing the loop", with reported rates that are orders of magnitude lower than those of pathways to upcycle plastic degradation products. We further find that neither degradation nor upcycling have been demonstrated at rates sufficiently high to justify industrialization at present. As a potential way to address these limitations, we suggest more investigation into mixotrophic approaches, showing that those which leverage the unique properties of plastic degradation products such as ethylene glycol might improve rates sufficiently to motivate industrial process development.
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Affiliation(s)
- Michael Weldon
- Department of Chemical Engineering, University of Waterloo, Canada
| | - Sanniv Ganguly
- Department of Chemical Engineering, University of Waterloo, Canada
| | - Christian Euler
- Department of Chemical Engineering, University of Waterloo, Canada
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3
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Moon TS. Be a GEM: Biocontained, environmentally applied, genetically engineered microbes. Adv Drug Deliv Rev 2025; 221:115578. [PMID: 40222715 PMCID: PMC12066214 DOI: 10.1016/j.addr.2025.115578] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2025] [Revised: 03/08/2025] [Accepted: 04/09/2025] [Indexed: 04/15/2025]
Abstract
Technological advances in engineering biology or synthetic biology have enabled practical applications of genetically engineered microbes (GEMs), including their use as living diagnostics and vehicles for therapeutics. However, technological and non-technological issues associated with biocontainment of GEMs have yet to be addressed before fully realizing their potential. In this short perspective, I briefly discuss the relevant technologies for GEM biocontainment as well as environmental impacts, regulatory issues, and public perception of GEMs.
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Affiliation(s)
- Tae Seok Moon
- Synthetic Biology Group, J. Craig Venter Institute, La Jolla, CA, United States.
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4
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Serafim LF, de Azambuja F, Rathee P, Wang L, Parac-Vogt TN, Prabhakar R. Hydrolytic Degradation of Key Plastic Pollutant Model Systems by a Discrete Metal-Oxo Cluster: A Combined Theoretical and Experimental Study. J Phys Chem B 2025. [PMID: 40390291 DOI: 10.1021/acs.jpcb.5c01255] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/21/2025]
Abstract
Degradation of plastic materials represents one of the major challenges faced by the modern world. In this study, computational and experimental techniques have been employed to investigate the hydrolysis of most commonly used plastic materials poly(ether urethane) (PEU) and polyethylene terephthalate (PET) and their commercially available models ethyl N-phenylcarbamate (ENP) and ethylene glycol dibenzoate (EGD), respectively, by a discrete metal-oxo cluster, Zr-substituted Keggin-type polyoxometalate, (Et2NH2)8[Zr(μ-O)(H2O)(PW11O39)] (ZrK), in which the Zr(IV) catalytic site is stabilized by coordination to a robust metal-oxo core. The all-atom molecular dynamics simulations predicted that all substrates interact with ZrK through water-mediated interactions. The quantum mechanics/molecular mechanics (QM/MM) calculations showed that the lengths of scissile ester and amide bonds of PEU/ENP and the ester bond of PET/EGD are quite similar, and the hydrolysis of PEU and ENP and PET and EGD occurs with similar energetics. According to the most plausible mechanisms, the cleavage of the ester and amide bonds of PEU/ENP takes place with a barrier of 16.5/16.6 and 19.0/20.4 kcal/mol, respectively. However, the scissile ester bond of PET/EGD is hydrolyzed with a barrier of 16.7/16.5 kcal/mol. This computed difference in the rate-limiting barrier of 3.9 kcal/mol between the amide bond of ENP and the ester bond of EGD is supported by the experimentally observed sluggish hydrolysis of ENP in comparison to EGD. While both ENP and EGD were successfully hydrolyzed by ZrK in DMSO solvent at 100 °C, EGD hydrolysis has proven to be much more efficient, with 99% yield obtained within 18 h compared to 48% of ENP hydrolysis observed after 162 h. The combined theoretical and experimental results presented here contribute to the development of potent and robust all-inorganic cluster-based catalysts for the degradation of PEU and PET and suggest that ENP and EGD can be used as excellent model substrates in this endeavor.
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Affiliation(s)
- Leonardo F Serafim
- Department of Chemistry, University of Miami, Coral Gables, Florida 33146, United States
| | | | - Parth Rathee
- Department of Chemistry, University of Miami, Coral Gables, Florida 33146, United States
| | - Lukun Wang
- Department of Chemistry, University of Miami, Coral Gables, Florida 33146, United States
| | | | - Rajeev Prabhakar
- Department of Chemistry, University of Miami, Coral Gables, Florida 33146, United States
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5
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Foka K, Ferousi C, Topakas E. Polyester-derived monomers as microbial feedstocks: Navigating the landscape of polyester upcycling. Biotechnol Adv 2025; 82:108589. [PMID: 40354902 DOI: 10.1016/j.biotechadv.2025.108589] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/01/2025] [Revised: 04/10/2025] [Accepted: 04/25/2025] [Indexed: 05/14/2025]
Abstract
Since their large-scale adoption in the early 20th century, plastics have become indispensable to modern life. However, inadequate disposal and recycling methods have led to severe environmental consequences. While traditional end-of-life plastics management had predominantly relied on landfilling, a paradigm shift towards recycling and valorization emerged in the 1970s, leading to the development of various, mostly mechanochemical, recycling strategies, together with the more recent approach of biological depolymerization and upcycling. Plastic upcycling, which converts plastic waste into higher-value products, is gaining attention as a sustainable strategy to reduce environmental impact and reliance on virgin materials. Microbial plastic upcycling relies on efficient depolymerization methods to generate monomeric substrates, which are subsequently metabolized by native or engineered microbial systems yielding valuable bioproducts. This review focuses on the second phase of microbial polyester upcycling, examining the intracellular metabolic pathways that enable the assimilation and bioconversion of polyester-derived monomers into industrially relevant compounds. Both biodegradable and non-biodegradable polyesters with commercial significance are considered, with emphasis on pure monomeric feedstocks to elucidate intracellular carbon assimilation pathways. Understanding these metabolic processes provides a foundation for future metabolic engineering efforts, aiming to optimize microbial systems for efficient bioconversion of mixed plastic hydrolysates into valuable bioproducts.
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Affiliation(s)
- Katerina Foka
- Industrial Biotechnology & Biocatalysis Group, Biotechnology Laboratory, School of Chemical Engineering, National Technical University of Athens, 15772 Athens, Greece.
| | - Christina Ferousi
- Industrial Biotechnology & Biocatalysis Group, Biotechnology Laboratory, School of Chemical Engineering, National Technical University of Athens, 15772 Athens, Greece.
| | - Evangelos Topakas
- Industrial Biotechnology & Biocatalysis Group, Biotechnology Laboratory, School of Chemical Engineering, National Technical University of Athens, 15772 Athens, Greece.
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6
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Orimaco R, Donnelly P, Sexton S, McLoughlin A, Kelly S, O'Connor KE, Wierckx N, Narančić T. Characterisation and Harnessing of 5-Hydroxymethylfurfural Metabolism in Pseudomonas umsongensis GO16 for the Production of 2,5-Furandicarboxylic Acid. Microb Biotechnol 2025; 18:e70159. [PMID: 40346906 PMCID: PMC12064950 DOI: 10.1111/1751-7915.70159] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2024] [Revised: 04/18/2025] [Accepted: 04/27/2025] [Indexed: 05/12/2025] Open
Abstract
In the search for biobased alternatives to traditional fossil plastics, 2,5-furandicarboxylic acid (FDCA) represents a potential substitute to terephthalic acid (TPA), a monomer of the ubiquitous polyester, polyethylene terephthalate (PET). Pseudomonas umsongensis GO16, which can metabolise TPA and ethylene glycol (EG), can also oxidise 5-hydroxymethylfurfural (HMF), a precursor to FDCA. The enzymes involved in the oxidation to FDCA, PsfA and PsfG, were identified and characterised. Deletion of FDCA decarboxylase HmfF involved in the conversion of FDCA to furoic acid, and subsequently to a central metabolic intermediate, 2-ketoglutarate, allowed for the accumulation of FDCA. GO16 ΔhmfF cells were grown on glycerol, TPA, EG or mock PET hydrolysate, and the catalyst was then used for the biotransformation of HMF to FDCA. When TPA was used as a growth substrate and to power the biotransformation, the transport of 5-hydroxymethyl-2-furancarboxylic acid (HMFCA) into the cytoplasm represented a rate-limiting step in HMF oxidation. De-bottlenecking transport limitations through in trans overexpression of the HMFCA transporter (HmfT) along with the PsfA aldehyde dehydrogenase and PsfG alcohol dehydrogenase allowed 100% conversion of 50 mM HMF to FDCA within 24 h when TPA, EG or mock PET hydrolysate were used to grow the biocatalyst and subsequently to power the biotransformation. This expands the repertoire of valuable products obtained from engineered P. umsongensis GO16 in the strategy to bio-upcycle post-consumer PET.
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Affiliation(s)
- Rhys Orimaco
- UCD Earth Institute and School of Biomolecular and Biomedical ScienceUniversity College DublinDublin 4Ireland
- BiOrbic ‐ Bioeconomy Research CentreIreland, University College DublinDublin 4Ireland
| | - Pauric Donnelly
- UCD Earth Institute and School of Biomolecular and Biomedical ScienceUniversity College DublinDublin 4Ireland
- BiOrbic ‐ Bioeconomy Research CentreIreland, University College DublinDublin 4Ireland
| | - Seán Sexton
- UCD Earth Institute and School of Biomolecular and Biomedical ScienceUniversity College DublinDublin 4Ireland
| | - Aoife McLoughlin
- UCD Earth Institute and School of Biomolecular and Biomedical ScienceUniversity College DublinDublin 4Ireland
| | - Sophie Kelly
- UCD Earth Institute and School of Biomolecular and Biomedical ScienceUniversity College DublinDublin 4Ireland
| | - Kevin E. O'Connor
- UCD Earth Institute and School of Biomolecular and Biomedical ScienceUniversity College DublinDublin 4Ireland
- BiOrbic ‐ Bioeconomy Research CentreIreland, University College DublinDublin 4Ireland
| | - Nick Wierckx
- Institute of bio‐ and Geosciences IBG‐1: BiotechnologyForschungszentrum JülichJülichGermany
| | - Tanja Narančić
- UCD Earth Institute and School of Biomolecular and Biomedical ScienceUniversity College DublinDublin 4Ireland
- BiOrbic ‐ Bioeconomy Research CentreIreland, University College DublinDublin 4Ireland
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7
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Pardo I, Manoli MT, Capel S, Calonge-García A, Prieto MA. Enzymatic recycling and microbial upcycling for a circular plastics bioeconomy. Curr Opin Biotechnol 2025; 93:103307. [PMID: 40311164 DOI: 10.1016/j.copbio.2025.103307] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2025] [Revised: 04/03/2025] [Accepted: 04/08/2025] [Indexed: 05/03/2025]
Abstract
Since the 1950s, plastics have become commodity materials that are present in virtually every aspect of our daily lives. However, the current economic model of plastics is fundamentally linear, with less than 10% of plastics returning to the value chain at their end of life. In recent years, efforts have been dedicated to develop new technologies that can change this model to a circular economy for plastics, including enzymatic recycling and biological upcycling to value-added products. Here, we will review recent advances made in this rapidly evolving field and discuss how further development of these technologies could contribute to reduce the share of postconsumer plastic waste that is diverted toward landfilling and incineration.
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Affiliation(s)
- Isabel Pardo
- Centro de Investigaciones Biológicas Margarita Salas, CSIC, Madrid, Spain; Interdisciplinary Platform SusPlast, CSIC, Spain.
| | - Maria T Manoli
- Centro de Investigaciones Biológicas Margarita Salas, CSIC, Madrid, Spain; Interdisciplinary Platform SusPlast, CSIC, Spain
| | - Susana Capel
- Centro de Investigaciones Biológicas Margarita Salas, CSIC, Madrid, Spain; Interdisciplinary Platform SusPlast, CSIC, Spain
| | - Alba Calonge-García
- Centro de Investigaciones Biológicas Margarita Salas, CSIC, Madrid, Spain; Interdisciplinary Platform SusPlast, CSIC, Spain
| | - M Auxiliadora Prieto
- Centro de Investigaciones Biológicas Margarita Salas, CSIC, Madrid, Spain; Interdisciplinary Platform SusPlast, CSIC, Spain
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8
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Gulati S, Sun Q. Complete Enzymatic Depolymerization of Polyethylene Terephthalate (PET) Plastic Using a Saccharomyces cerevisiae-Based Whole-Cell Biocatalyst. ENVIRONMENTAL SCIENCE & TECHNOLOGY LETTERS 2025; 12:419-424. [PMID: 40224494 PMCID: PMC11984091 DOI: 10.1021/acs.estlett.5c00190] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 02/26/2025] [Revised: 03/06/2025] [Accepted: 03/07/2025] [Indexed: 04/15/2025]
Abstract
Management of polyethylene terephthalate (PET) plastic waste remains a challenge. PET-hydrolyzing enzymes (PHEs) such as IsPETase and variants like FAST-PETase demonstrate promising PET depolymerization capabilities at ambient temperatures and can be utilized to recycle and upcycle plastic waste. Whole-cell biocatalysts displaying PHEs on their surface offer high efficiency, reusability, and stability for PET depolymerization. However, their efficacy in fully breaking down PET is hindered by the necessity of two enzymes: PETase and MHETase. Current whole-cell systems either display only one enzyme or struggle with performance when displaying larger enzymes such as the MHETase-PETase chimera. We developed a Saccharomyces cerevisiae-based whole-cell biocatalyst for complete depolymerization of PET into its constituent monomers with no accumulation of intermediate products. Leveraging a cellulosome-inspired trifunctional protein scaffoldin displayed on the yeast surface, we co-immobilized FAST-PETase and MHETase, forming a multi-enzyme cluster. This whole-cell biocatalyst achieved complete PET depolymerization at 30 °C, yielding 4.95 mM terephthalic acid (TPA) when tested on a PET film. Furthermore, we showed improved PET depolymerization ability by binding FAST-PETase at multiple sites on the scaffoldin. The whole cells had the added advantage of retained activity over multiple reusability cycles. This breakthrough in complete PET depolymerization marks a step toward a circular plastic economy.
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Affiliation(s)
- Siddhant Gulati
- Department
of Chemical Engineering, Texas A&M University, College Station, Texas 77843, United States
| | - Qing Sun
- Department
of Chemical Engineering, Texas A&M University, College Station, Texas 77843, United States
- Interdisciplinary
Graduate Program in Genetics and Genomics, Texas A&M University, College
Station, Texas 77843, United States
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9
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Xu VA, Lee H, Long B, Yuan J, Tang YJ. MAGMA: Microbial and Algal Growth Modeling Application. N Biotechnol 2025; 85:16-22. [PMID: 39603522 DOI: 10.1016/j.nbt.2024.11.004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2024] [Revised: 10/29/2024] [Accepted: 11/21/2024] [Indexed: 11/29/2024]
Abstract
Kinetic modeling of biochemical reactions and bioreactor systems can enhance and quantify knowledge gained from cell culture experiments and has many applications in bioprocess design and optimization. The Microbial and Algal Growth Modeling Application (MAGMA) is a user-friendly MATLAB-based software for streamlining the development of kinetic models for various bioreactor systems. This study details the MAGMA workflow by demonstrating the creation of kinetic models with systems of ordinary differential equations (ODEs), model fitting by solving inverse problems, statistical evaluation of model fitting quality, and visual display of simulation results. Two case studies (microalgae growth and Rhodococcus jostii plastic fermentation) have been provided to validate MAGMA applicability. It also includes a proof-of-concept for utilizing OpenAI GPT-4o's graph interpretation capability to automate tabulation of time course culture data from figures/plots in relevant literature, which can be used to calibrate model parameters. MAGMA is open source and compiled with MATLAB Runtime.
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Affiliation(s)
- Vincent A Xu
- Department of Energy, Environmental, and Chemical Engineering, Washington University in St. Louis, St. Louis, MO 63130, USA.
| | - Hakyung Lee
- Department of Energy, Environmental, and Chemical Engineering, Washington University in St. Louis, St. Louis, MO 63130, USA.
| | - Bin Long
- Department of Energy, Environmental, and Chemical Engineering, Washington University in St. Louis, St. Louis, MO 63130, USA.
| | - Joshua Yuan
- Department of Energy, Environmental, and Chemical Engineering, Washington University in St. Louis, St. Louis, MO 63130, USA.
| | - Yinjie J Tang
- Department of Energy, Environmental, and Chemical Engineering, Washington University in St. Louis, St. Louis, MO 63130, USA.
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10
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Wang N, Zhang Q, Sun Z, Zhang H, Hu C, Sun H, Pang X, Chen X. Recycling Polyester and Polycarbonate Plastics with Carbocation Lewis Acidic Organocatalysts. ACS Macro Lett 2025; 14:377-384. [PMID: 40056447 DOI: 10.1021/acsmacrolett.5c00054] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/10/2025]
Abstract
The effective management of plastic waste is critical for environmental sustainability. This work explores the use of carbocation catalysts for the recycling of common polyesters and polycarbonates through alcoholysis. We demonstrate complete depolymerization of end-of-life materials and investigate the relationship between the catalytic reactivity and the structural features of the carbocation compounds, including the cations and their counteranions. Carbocations function as Lewis acids, facilitating the interaction with carbonyls in polymer chains. Moreover, our approach enables the hierarchical degradation of the polyester blends. This research not only elucidates the catalytic role of carbocations in the alcoholysis of these polymers, but also establishes a metal-free process for the efficient recycling of waste plastics.
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Affiliation(s)
- Nan Wang
- Key Laboratory of Polymer Ecomaterials, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, 5625 Renmin Street, Changchun 130022, China
- School of Applied Chemistry and Engineering, University of Science and Technology of China, Hefei 230026, China
| | - Qiao Zhang
- Key Laboratory of Polymer Ecomaterials, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, 5625 Renmin Street, Changchun 130022, China
| | - Zhiqiang Sun
- Key Laboratory of Polymer Ecomaterials, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, 5625 Renmin Street, Changchun 130022, China
| | - Han Zhang
- Key Laboratory of Polymer Ecomaterials, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, 5625 Renmin Street, Changchun 130022, China
| | - Chenyang Hu
- Key Laboratory of Polymer Ecomaterials, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, 5625 Renmin Street, Changchun 130022, China
| | - Hai Sun
- Key Laboratory of Polymer Ecomaterials, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, 5625 Renmin Street, Changchun 130022, China
| | - Xuan Pang
- Key Laboratory of Polymer Ecomaterials, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, 5625 Renmin Street, Changchun 130022, China
- School of Applied Chemistry and Engineering, University of Science and Technology of China, Hefei 230026, China
| | - Xuesi Chen
- Key Laboratory of Polymer Ecomaterials, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, 5625 Renmin Street, Changchun 130022, China
- School of Applied Chemistry and Engineering, University of Science and Technology of China, Hefei 230026, China
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11
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Liu XH, Jin JL, Sun HT, Li S, Zhang FF, Yu XH, Cao QZ, Song YX, Li N, Lu ZH, Wang T, Liu F, Wang JM. Perspectives on the microorganisms with the potentials of PET-degradation. Front Microbiol 2025; 16:1541913. [PMID: 40143857 PMCID: PMC11938130 DOI: 10.3389/fmicb.2025.1541913] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2024] [Accepted: 02/14/2025] [Indexed: 03/28/2025] Open
Abstract
Polyethylene terephthalate (PET), a widely used synthetic polymer in daily life, has become a major source of post-consumer waste due to its complex molecular structure and resistance to natural degradation, which has posed a significant threat to the global ecological environment and human health. Current PET-processing methods include physical, chemical, and biological approaches, however each have their limitations. Given that numerous microbial strains exhibit a remarkable capacity to degrade plastic materials, microbial degradation of PET has emerged as a highly promising alternative. This approach not only offers the possibility of converting waste into valuable resources but also contributes to the advancement of a circular economy. Therefore in this review, it is mainly focused on the cutting-edge microbial technologies and the key role of specific microbial strains such as Ideonella sakaiensis 201-F6, which can efficiently degrade and assimilate PET. Particularly noteworthy are the catalytic enzymes related to the metabolism of PET, which have been emphasized as a sustainable and eco-friendly strategy for plastic recycling within the framework of a circular economy. Furthermore, the study also elucidates the innovative utilization of degraded plastic materials as feedstock for the production of high-value chemicals, highlighting a sustainable path forward in the management of plastic waste.
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Affiliation(s)
- Xiao-huan Liu
- School of Biological Science, Jining Medical University, Jining, China
| | - Jun-li Jin
- School of Biological Science, Jining Medical University, Jining, China
| | - Hai-tong Sun
- School of Biological Science, Jining Medical University, Jining, China
| | - Shuo Li
- School of Biological Science, Jining Medical University, Jining, China
| | - Fei-fei Zhang
- School of Biological Science, Jining Medical University, Jining, China
| | - Xin-hong Yu
- School of Biological Science, Jining Medical University, Jining, China
| | - Qi-zhi Cao
- School of Biological Science, Jining Medical University, Jining, China
| | - Yu-xuan Song
- School of Biological Science, Jining Medical University, Jining, China
| | - Nan Li
- School of Biological Science, Jining Medical University, Jining, China
| | - Zhen-hua Lu
- College of Chemical and Biological Engineering, Zhejiang University, Hangzhou, China
| | - Tao Wang
- School of Biological Science, Jining Medical University, Jining, China
| | - Fei Liu
- School of Biological Science, Jining Medical University, Jining, China
| | - Jian-min Wang
- School of Pharmacy, Jining Medical University, Rizhao, China
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12
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Chacón M, Alvarez-Gonzalez G, Gosalvitr P, Berepiki A, Fisher K, Cuéllar-Franca R, Dixon N. Complex waste stream valorization through combined enzymatic hydrolysis and catabolic assimilation by Pseudomonas putida. Trends Biotechnol 2025; 43:647-672. [PMID: 39638703 DOI: 10.1016/j.tibtech.2024.10.020] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2024] [Revised: 10/28/2024] [Accepted: 10/31/2024] [Indexed: 12/07/2024]
Abstract
Biogenic waste-derived feedstocks for production of fuels, chemicals, and materials offer great potential supporting the transition to net-zero and greater circularity. However, such feedstocks are heterogeneous and subject to geographical and seasonal variability. Here, we show that, through careful strain selection and metabolic engineering, Pseudomonas putida can be employed to permit efficient co-utilization of highly heterogeneous substrate compositions derived from hydrolyzed mixed municipal-like waste fractions (food, plastic, organic, paper, cardboard, and textiles) for growth and synthesis of exemplar bioproducts. Design of experiments was employed to explore the combinatorial space of nine waste-derived monomers, displaying robust catabolic efficiency regardless of substrate composition. Prospective Life-Cycle Assessment (LCA) and Life-Cycle Costing (LCC) illustrated the climate change (CC) and economic advantages of biomanufacturing compared with conventional waste treatment options, demonstrating a 41-62% potential reduction in CC impact. This work demonstrates the potential for expanding treatment strategies for mixed waste to include engineered microbes.
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Affiliation(s)
- Micaela Chacón
- Manchester Institute of Biotechnology (MIB), Department of Chemistry, University of Manchester, Manchester, M1 7DN, UK
| | - Guadalupe Alvarez-Gonzalez
- Manchester Institute of Biotechnology (MIB), Department of Chemistry, University of Manchester, Manchester, M1 7DN, UK
| | - Piya Gosalvitr
- Department of Chemical Engineering, University of Manchester, Manchester, M13 9PL, UK
| | - Adokiye Berepiki
- Manchester Institute of Biotechnology (MIB), Department of Chemistry, University of Manchester, Manchester, M1 7DN, UK
| | - Karl Fisher
- Manchester Institute of Biotechnology (MIB), Department of Chemistry, University of Manchester, Manchester, M1 7DN, UK
| | - Rosa Cuéllar-Franca
- Department of Chemical Engineering, University of Manchester, Manchester, M13 9PL, UK
| | - Neil Dixon
- Manchester Institute of Biotechnology (MIB), Department of Chemistry, University of Manchester, Manchester, M1 7DN, UK.
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13
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Werner AZ, Avina YSC, Johnsen J, Bratti F, Alt HM, Mohamed ET, Clare R, Mand TD, Guss AM, Feist AM, Beckham GT. Adaptive laboratory evolution and genetic engineering improved terephthalate utilization in Pseudomonas putida KT2440. Metab Eng 2025; 88:196-205. [PMID: 39701409 DOI: 10.1016/j.ymben.2024.12.006] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2024] [Revised: 12/06/2024] [Accepted: 12/16/2024] [Indexed: 12/21/2024]
Abstract
Poly (ethylene terephthalate) (PET) is one of the most ubiquitous plastics and can be depolymerized through biological and chemo-catalytic routes to its constituent monomers, terephthalic acid (TPA) and ethylene glycol (EG). TPA and EG can be re-synthesized into PET for closed-loop recycling or microbially converted into higher-value products for open-loop recycling. Here, we expand on our previous efforts engineering and applying Pseudomonas putida KT2440 for PET conversion by employing adaptive laboratory evolution (ALE) to improve TPA catabolism. Three P. putida strains with varying degrees of metabolic engineering for EG catabolism underwent an automation-enabled ALE campaign on TPA, a TPA and EG mixture, and glucose as a control. ALE increased the growth rate on TPA and TPA-EG mixtures by 4.1- and 3.5-fold, respectively, in approximately 350 generations. Evolved isolates were collected at the midpoints and endpoints of 39 independent ALE experiments, and growth rates were increased by 0.15 and 0.20 h-1 on TPA and a TPA-EG, respectively, in the best performing isolates. Whole-genome re-sequencing identified multiple converged mutations, including loss-of-function mutations to global regulators gacS, gacA, and turA along with large duplication and intergenic deletion events that impacted the heterologously-expressed tphABII catabolic genes. Reverse engineering of these targets confirmed causality, and a strain with all three regulators deleted and second copies of tphABII and tpaK displayed improved TPA utilization compared to the base strain. Taken together, an iterative strain engineering process involving heterologous pathway engineering, ALE, whole genome sequencing, and genome editing identified five genetic interventions that improve P. putida growth on TPA, aimed at developing enhanced whole-cell biocatalysts for PET upcycling.
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Affiliation(s)
- Allison Z Werner
- Renewable Resources and Enabling Sciences Center, National Renewable Energy Laboratory, Golden, CO, USA; BOTTLE Consortium, Golden, CO, USA
| | - Young-Saeng C Avina
- Renewable Resources and Enabling Sciences Center, National Renewable Energy Laboratory, Golden, CO, USA; BOTTLE Consortium, Golden, CO, USA
| | - Josefin Johnsen
- Novo Nordisk Foundation Center for Biosustainability, Technical University of Denmark, Lyngby, Denmark
| | - Felicia Bratti
- Renewable Resources and Enabling Sciences Center, National Renewable Energy Laboratory, Golden, CO, USA; BOTTLE Consortium, Golden, CO, USA
| | - Hannah M Alt
- Renewable Resources and Enabling Sciences Center, National Renewable Energy Laboratory, Golden, CO, USA
| | - Elsayed T Mohamed
- Novo Nordisk Foundation Center for Biosustainability, Technical University of Denmark, Lyngby, Denmark
| | - Rita Clare
- Renewable Resources and Enabling Sciences Center, National Renewable Energy Laboratory, Golden, CO, USA; BOTTLE Consortium, Golden, CO, USA
| | - Thomas D Mand
- BOTTLE Consortium, Golden, CO, USA; Biosciences Division, Oak Ridge National Laboratory, One Bethel Valley Road, Oak Ridge, TN, USA
| | - Adam M Guss
- BOTTLE Consortium, Golden, CO, USA; Biosciences Division, Oak Ridge National Laboratory, One Bethel Valley Road, Oak Ridge, TN, USA
| | - Adam M Feist
- Novo Nordisk Foundation Center for Biosustainability, Technical University of Denmark, Lyngby, Denmark; Department of Bioengineering, University of California, San Diego, CA, USA.
| | - Gregg T Beckham
- Renewable Resources and Enabling Sciences Center, National Renewable Energy Laboratory, Golden, CO, USA; BOTTLE Consortium, Golden, CO, USA.
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14
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Diao J, Tian Y, Hu Y, Moon TS. Producing multiple chemicals through biological upcycling of waste poly(ethylene terephthalate). Trends Biotechnol 2025; 43:620-646. [PMID: 39581772 DOI: 10.1016/j.tibtech.2024.10.018] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2024] [Revised: 10/26/2024] [Accepted: 10/31/2024] [Indexed: 11/26/2024]
Abstract
Poly(ethylene terephthalate) (PET) waste is of low degradability in nature, and its mismanagement threatens numerous ecosystems. To combat the accumulation of waste PET in the biosphere, PET bio-upcycling, which integrates chemical pretreatment to produce PET-derived monomers with their microbial conversion into value-added products, has shown promise. The recently discovered Rhodococcus jostii RPET strain can metabolically degrade terephthalic acid (TPA) and ethylene glycol (EG) as sole carbon sources, and it has been developed into a microbial chassis for PET upcycling. However, the scarcity of synthetic biology tools, specifically designed for this non-model microbe, limits the development of a microbial cell factory for expanding the repertoire of bioproducts from postconsumer PET. Herein, we describe the development of potent genetic tools for RPET, including two inducible and titratable expression systems for tunable gene expression, along with serine integrase-based recombinational tools (SIRT) for genome editing. Using these tools, we systematically engineered the RPET strain to ultimately establish microbial supply chains for producing multiple chemicals, including lycopene, lipids, and succinate, from postconsumer PET waste bottles, achieving the highest titer of lycopene ever reported thus far in RPET [i.e., 22.6 mg/l of lycopene, ~10 000-fold higher than that of the wild-type (WT) strain]. This work highlights the great potential of plastic upcycling as a generalizable means of sustainable production of diverse chemicals.
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Affiliation(s)
- Jinjin Diao
- Department of Energy, Environmental, and Chemical Engineering, Washington University in St Louis, St Louis, MO 63130, USA.
| | - Yuxin Tian
- Department of Energy, Environmental, and Chemical Engineering, Washington University in St Louis, St Louis, MO 63130, USA; Synthetic Biology Group, J. Craig Venter Institute, La Jolla, CA 92037, USA
| | - Yifeng Hu
- Department of Energy, Environmental, and Chemical Engineering, Washington University in St Louis, St Louis, MO 63130, USA
| | - Tae Seok Moon
- Department of Energy, Environmental, and Chemical Engineering, Washington University in St Louis, St Louis, MO 63130, USA; Division of Biology and Biomedical Sciences, Washington University in St Louis, St Louis, MO 63130, USA; Synthetic Biology Group, J. Craig Venter Institute, La Jolla, CA 92037, USA.
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15
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Welsing G, Wolter B, Kleinert GEK, Göttsch F, Besenmatter W, Xue R, Mauri A, Steffens D, Köbbing S, Dong W, Jiang M, Bornscheuer UT, Wei R, Tiso T, Blank LM. Two-step biocatalytic conversion of post-consumer polyethylene terephthalate into value-added products facilitated by genetic and bioprocess engineering. BIORESOURCE TECHNOLOGY 2025; 417:131837. [PMID: 39557102 DOI: 10.1016/j.biortech.2024.131837] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/12/2024] [Revised: 10/27/2024] [Accepted: 11/15/2024] [Indexed: 11/20/2024]
Abstract
Solving the plastic crisis requires high recycling quotas and technologies that allow open loop recycling. Here a biological plastic valorization approach consisting of tandem enzymatic hydrolysis and monomer conversion of post-consumer polyethylene terephthalate into value-added products is presented. Hydrolysates obtained from enzymatic degradation of pre-treated post-consumer polyethylene terephthalate bottles in a stirred-tank reactor served as the carbon source for a batch fermentation with an engineered Pseudomonas putida strain to produce 90mg/L of the biopolymer cyanophycin. Through fed-batch operation, the fermentation could be intensified to 1.4 g/L cyanophycin. Additionally, the upcycling of polyethylene terephthalate monomers to the biosurfactants (hydroxyalkanoyloxy)alkanoates and rhamnolipids is presented. These biodegradable products hold significant potential for applications in areas such as detergents, building blocks for novel polymers, and tissue engineering. In summary, the presented bio-valorization process underscores that addressing challenges like the plastic crisis requires an interdisciplinary approach.
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Affiliation(s)
- Gina Welsing
- RWTH Aachen University, Institute of Applied Microbiology (iAMB), Worringer Weg 1, 52074 Aachen, Germany.
| | - Birger Wolter
- RWTH Aachen University, Institute of Applied Microbiology (iAMB), Worringer Weg 1, 52074 Aachen, Germany.
| | - Greta E K Kleinert
- RWTH Aachen University, Institute of Applied Microbiology (iAMB), Worringer Weg 1, 52074 Aachen, Germany.
| | - Frederike Göttsch
- University of Greifswald, Institute of Biochemistry, Department of Biotechnology & Enzyme Catalysis, Felix-Hausdorff-Str. 4, 17487 Greifswald, Germany.
| | | | - Rui Xue
- Key Laboratory for Waste Plastics Biocatalytic Degradation and Recycling, 30 South Puzhu Road, Nanjing Tech University, Nanjing, Jiangsu 211800, PR China.
| | - Alessandra Mauri
- RWTH Aachen University, Institute of Applied Microbiology (iAMB), Worringer Weg 1, 52074 Aachen, Germany.
| | - Dominik Steffens
- RWTH Aachen University, Institute of Applied Microbiology (iAMB), Worringer Weg 1, 52074 Aachen, Germany.
| | - Sebastian Köbbing
- RWTH Aachen University, Institute of Applied Microbiology (iAMB), Worringer Weg 1, 52074 Aachen, Germany.
| | - Weiliang Dong
- Key Laboratory for Waste Plastics Biocatalytic Degradation and Recycling, 30 South Puzhu Road, Nanjing Tech University, Nanjing, Jiangsu 211800, PR China.
| | - Min Jiang
- Key Laboratory for Waste Plastics Biocatalytic Degradation and Recycling, 30 South Puzhu Road, Nanjing Tech University, Nanjing, Jiangsu 211800, PR China.
| | - Uwe T Bornscheuer
- University of Greifswald, Institute of Biochemistry, Department of Biotechnology & Enzyme Catalysis, Felix-Hausdorff-Str. 4, 17487 Greifswald, Germany.
| | - Ren Wei
- University of Greifswald, Institute of Biochemistry, Department of Biotechnology & Enzyme Catalysis, Felix-Hausdorff-Str. 4, 17487 Greifswald, Germany.
| | - Till Tiso
- RWTH Aachen University, Institute of Applied Microbiology (iAMB), Worringer Weg 1, 52074 Aachen, Germany.
| | - Lars M Blank
- RWTH Aachen University, Institute of Applied Microbiology (iAMB), Worringer Weg 1, 52074 Aachen, Germany.
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16
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Lee H, Diao J, Tian Y, Guleria R, Lee E, Smith A, Savage M, Yeh D, Roberson L, Blenner M, Tang YJ, Moon TS. Developing an alternative medium for in-space biomanufacturing. Nat Commun 2025; 16:728. [PMID: 39819985 PMCID: PMC11739595 DOI: 10.1038/s41467-025-56088-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2024] [Accepted: 01/08/2025] [Indexed: 01/19/2025] Open
Abstract
In-space biomanufacturing provides a sustainable solution to facilitate long-term, self-sufficient human habitation in extraterrestrial environments. However, its dependence on Earth-supplied feedstocks renders in-space biomanufacturing economically nonviable. Here, we develop a process termed alternative feedstock-driven in-situ biomanufacturing (AF-ISM) to alleviate dependence on Earth-based resupply of feedstocks. Specifically, we investigate three alternative feedstocks (AF)-Martian and Lunar regolith, post-consumer polyethylene terephthalate, and fecal waste-to develop an alternative medium for lycopene production using Rhodococcus jostii PET strain S6 (RPET S6). Our results show that RPET S6 could directly utilize regolith simulant particles as mineral replacements, while the addition of anaerobically pretreated fecal waste synergistically supported its cell growth. Additionally, lycopene production using AF under microgravity conditions achieved levels comparable to those on Earth. Furthermore, an economic analysis shows significant lycopene production cost reductions using AF-ISM versus conventional methods. Overall, this work highlights the viability of AF-ISM for in-space biomanufacturing.
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Affiliation(s)
- Hakyung Lee
- Washington University in St. Louis, Saint Louis, MO, USA
| | - Jinjin Diao
- Washington University in St. Louis, Saint Louis, MO, USA.
| | - Yuxin Tian
- Washington University in St. Louis, Saint Louis, MO, USA
- Synthetic Biology Group, J. Craig Venter Institute, La Jolla, CA, USA
| | | | - Eunseo Lee
- Washington University in St. Louis, Saint Louis, MO, USA
| | | | - Millie Savage
- Lincoln University of Missouri, Jefferson City, MO, USA
| | - Daniel Yeh
- University of South Florida, Tampa, FL, USA
| | - Luke Roberson
- National Aeronautics and Space Administration, John F. Kennedy Space Center, Merritt Island, FL, USA
| | | | - Yinjie J Tang
- Washington University in St. Louis, Saint Louis, MO, USA.
| | - Tae Seok Moon
- Washington University in St. Louis, Saint Louis, MO, USA.
- Synthetic Biology Group, J. Craig Venter Institute, La Jolla, CA, USA.
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17
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Qin J, Wu F, Dou Y, Zhao D, Hélix-Nielsen C, Zhang W. Advanced Catalysts for the Chemical Recycling of Plastic Waste. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2025:e2418138. [PMID: 39748624 DOI: 10.1002/adma.202418138] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/21/2024] [Revised: 12/02/2024] [Indexed: 01/04/2025]
Abstract
Plastic products bring convenience to various aspects of the daily lives due to their lightweight, durability and versatility, but the massive accumulation of post-consumer plastic waste is posing significant environmental challenges. Catalytic methods can effectively convert plastic waste into value-added feedstocks, with catalysts playing an important role in regulating the yield and selectivity of products. This review explores the latest advancements in advanced catalysts applied in thermal catalysis, microwave-assisted catalysis, photocatalysis, electrocatalysis, and enzymatic catalysis reaction systems for the chemical recycling of plastic waste into valuable feedstocks. Specifically, the pathways and mechanisms involved in the plastics recycling process are analyzed and presented, and the strengths and weaknesses of various catalysts employed across different reaction systems are described. In addition, the structure-function relationship of these catalysts is discussed. Herein, it is provided insights into the design of novel catalysts applied for the chemical recycling of plastic waste and outline challenges and future opportunities in terms of developing advanced catalysts to tackle the "white pollution" crisis.
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Affiliation(s)
- Jibo Qin
- Department of Environmental and Resource Engineering, Technical University of Denmark, Kongens Lyngby, 2800, Denmark
- Industrial Catalysis Center, Department of Chemical Engineering, Tsinghua University, Beijing, 100084, P. R. China
| | - Feiyan Wu
- Department of Environmental and Resource Engineering, Technical University of Denmark, Kongens Lyngby, 2800, Denmark
| | - Yibo Dou
- State Key Laboratory of Chemical Resource Engineering, Beijing University of Chemical Technology, Beijing, 100029, P. R. China
- Institute for Innovation in Resource Chemical Engineering, Quzhou, Zhejiang Province, 324000, P. R. China
| | - Dan Zhao
- Department of Environmental and Resource Engineering, Technical University of Denmark, Kongens Lyngby, 2800, Denmark
| | - Claus Hélix-Nielsen
- Department of Environmental and Resource Engineering, Technical University of Denmark, Kongens Lyngby, 2800, Denmark
| | - Wenjing Zhang
- Department of Environmental and Resource Engineering, Technical University of Denmark, Kongens Lyngby, 2800, Denmark
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18
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Schaerer LG, Aloba S, Wood E, Olson AM, Valencia IB, Ong RG, Techtmann SM. Enriched microbial consortia from natural environments reveal core groups of microbial taxa able to degrade terephthalate and terphthalamide. PLoS One 2024; 19:e0315432. [PMID: 39729501 DOI: 10.1371/journal.pone.0315432] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2024] [Accepted: 11/25/2024] [Indexed: 12/29/2024] Open
Abstract
Millions of tons of polyethylene terephthalate (PET) are produced each year, however only ~30% of PET is currently recycled in the United States. Improvement of PET recycling and upcycling practices is an area of ongoing research. One method for PET upcycling is chemical depolymerization (through hydrolysis or aminolysis) into aromatic monomers and subsequent biodegradation. Hydrolysis depolymerizes PET into terephthalate, while aminolysis yields terephthalamide. Aminolysis, which is catalyzed with strong bases, yields products with high osmolality, which is inhibitory to optimal microbial growth. Additionally, terephthalamide, may be antimicrobial and its biodegradability is presently unknown. In this study, microbial communities were enriched from sediments collected from five unique environments to degrade either terephthalate or terephthalamide by performing biweekly transfers to fresh media and substrate. 16S rRNA sequencing was used to identify the dominant taxa in the enrichment cultures which may have terephthalate or terephthalamide-degrading metabolisms and compare them to the control enrichments. The goals of this study are to evaluate (1) how widespread terephthalate and terephthalamide degrading metabolisms are in natural environments, and (2) determine whether terephthalamide is biodegradable and identify microorganisms able to degrade it. The results presented here show that known contaminant-degrading genera were present in all the enriched microbial communities. Additionally, results show that terephthalamide (previously thought to be antimicrobial) was biodegraded by these enriched communities, suggesting that aminolysis may be a viable method for paired chemical and biological upcycling of PET.
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Affiliation(s)
- Laura G Schaerer
- Department of Biological Sciences, Michigan Technological University, Houghton, Michigan, United States of America
| | - Sulihat Aloba
- Department of Chemical Engineering, Michigan Technological University, Houghton, Michigan, United States of America
| | - Emily Wood
- Department of Biological Sciences, Michigan Technological University, Houghton, Michigan, United States of America
| | - Allison M Olson
- Department of Biological Sciences, Michigan Technological University, Houghton, Michigan, United States of America
| | - Isabel B Valencia
- Department of Biological Sciences, Michigan Technological University, Houghton, Michigan, United States of America
| | - Rebecca G Ong
- Department of Chemical Engineering, Michigan Technological University, Houghton, Michigan, United States of America
| | - Stephen M Techtmann
- Department of Biological Sciences, Michigan Technological University, Houghton, Michigan, United States of America
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19
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Muszyński M, Nowicki J, Krasuska A, Nowakowska-Bogdan E, Bartoszewicz M, Woszczyński P, Zygadło M, Dudek G. Synthesis of Bis(isodecyl Terephthalate) from Waste Poly(ethylene Terephthalate) Catalyzed by Lewis Acid Catalysts. Int J Mol Sci 2024; 25:12953. [PMID: 39684664 DOI: 10.3390/ijms252312953] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2024] [Revised: 11/27/2024] [Accepted: 11/27/2024] [Indexed: 12/18/2024] Open
Abstract
Increasing plastic waste generation has become a pressing environmental problem. One of the most produced waste plastics originates from post-consumer packaging, of which PET constitutes a significant portion. Despite increasing recycling rates, its accumulation has created a need for the development of new recycling methods that can further expand the possibilities of recycling. In this paper, we present the application of Lewis acid catalysts for the depolymerization of PET waste. The obtained results show the formation of diisodecyl terephthalate (DIDTP), which is used as a PVC plasticizer. For this purpose, several Lewis acid catalysts were tested, including tin, cobalt, manganese, zirconium, zinc, and calcium derivatives, alongside zinc acetate and potassium hydroxide, which were used as reference catalysts. Our results show that tin (II) oxalate is the most effective catalyst, and it was then used to synthesize two application samples (crude and purified). The physicochemical properties of PVC mixtures with the obtained samples were determined and compared to commercial plasticizers, where both plasticizers had similar plasticizing properties to PVC plasticization.
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Affiliation(s)
- Marcin Muszyński
- Department of Physical Chemistry and Technology of Polymers, Faculty of Chemistry, PhD School, Silesian University of Technology, ks. M. Strzody 9, 44-100 Gliwice, Poland
- Łukasiewicz Research Network-Institute of Heavy Organic Synthesis "Blachownia", Energetyków 9, 47-225 Kędzierzyn-Koźle, Poland
| | - Janusz Nowicki
- Łukasiewicz Research Network-Institute of Heavy Organic Synthesis "Blachownia", Energetyków 9, 47-225 Kędzierzyn-Koźle, Poland
| | - Agata Krasuska
- Łukasiewicz Research Network-Institute of Heavy Organic Synthesis "Blachownia", Energetyków 9, 47-225 Kędzierzyn-Koźle, Poland
| | - Ewa Nowakowska-Bogdan
- Łukasiewicz Research Network-Institute of Heavy Organic Synthesis "Blachownia", Energetyków 9, 47-225 Kędzierzyn-Koźle, Poland
| | - Maria Bartoszewicz
- Łukasiewicz Research Network-Institute of Heavy Organic Synthesis "Blachownia", Energetyków 9, 47-225 Kędzierzyn-Koźle, Poland
| | - Piotr Woszczyński
- Łukasiewicz Research Network-Institute of Heavy Organic Synthesis "Blachownia", Energetyków 9, 47-225 Kędzierzyn-Koźle, Poland
| | - Mateusz Zygadło
- Department of Physical Chemistry and Technology of Polymers, Faculty of Chemistry, Silesian University of Technology, Chemistry Students Research Society ks. M. Strzody 9, 44-100 Gliwice, Poland
| | - Gabriela Dudek
- Department of Physical Chemistry and Technology of Polymers, Faculty of Chemistry, Silesian University of Technology, ks. M. Strzody 9, 44-100 Gliwice, Poland
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20
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Hu Y, Tian Y, Zou C, Moon TS. The current progress of tandem chemical and biological plastic upcycling. Biotechnol Adv 2024; 77:108462. [PMID: 39395608 DOI: 10.1016/j.biotechadv.2024.108462] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2024] [Revised: 08/31/2024] [Accepted: 10/03/2024] [Indexed: 10/14/2024]
Abstract
Each year, millions of tons of plastics are produced for use in such applications as packaging, construction, and textiles. While plastic is undeniably useful and convenient, its environmental fate and transport have raised growing concerns about waste and pollution. However, the ease and low cost of producing virgin plastic have so far made conventional plastic recycling economically unattractive. Common contaminants in plastic waste and shortcomings of the recycling processes themselves typically mean that recycled plastic products are of relatively low quality in some cases. The high cost and high energy requirements of typical recycling operations also reduce their economic benefits. In recent years, the bio-upcycling of chemically treated plastic waste has emerged as a promising alternative to conventional plastic recycling. Unlike recycling, bio-upcycling uses relatively mild process conditions to economically transform pretreated plastic waste into value-added products. In this review, we first provide a précis of the general methodology and limits of conventional plastic recycling. Then, we review recent advances in hybrid chemical/biological upcycling methods for different plastics, including polyethylene terephthalate, polyurethane, polyamide, polycarbonate, polyethylene, polypropylene, polystyrene, and polyvinyl chloride. For each kind of plastic, we summarize both the pretreatment methods for making the plastic bio-available and the microbial chassis for degrading or converting the treated plastic waste to value-added products. We also discuss both the limitations of upcycling processes for major plastics and their potential for bio-upcycling.
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Affiliation(s)
- Yifeng Hu
- Department of Energy, Environmental and Chemical Engineering, Washington University in St. Louis, St. Louis, MO, United States
| | - Yuxin Tian
- Department of Energy, Environmental and Chemical Engineering, Washington University in St. Louis, St. Louis, MO, United States
| | - Chenghao Zou
- Department of Energy, Environmental and Chemical Engineering, Washington University in St. Louis, St. Louis, MO, United States
| | - Tae Seok Moon
- Department of Energy, Environmental and Chemical Engineering, Washington University in St. Louis, St. Louis, MO, United States; Division of Biology and Biomedical Sciences, Washington University in St. Louis, St. Louis, MO, United States; Synthetic Biology Group, J. Craig Venter Institute, La Jolla, CA, United States.
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21
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Nenadović M, Maršavelski A, Bogojević SŠ, Maslak V, Nikodinović-Runić J, Milovanović J. New model compounds for the efficient colorimetric screening of medium chain length polyhydroxyalkanoate (mcl-PHA) depolymerases reveal mechanism of activity. Int J Biol Macromol 2024; 283:137672. [PMID: 39566772 DOI: 10.1016/j.ijbiomac.2024.137672] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2024] [Revised: 11/04/2024] [Accepted: 11/13/2024] [Indexed: 11/22/2024]
Abstract
Plastic pollution presents a significant environmental problem contributing to increased CO2 emissions and persistently accumulation in ecosystems. Biobased polymers, like polyhydroxyalkanoates (PHAs), offer a part of a solution with their biodegradability and reduced carbon footprint. However, effective end-of-life strategies, such as controlled enzymatic depolymerization, are crucial for sustainability, relying on efficient PHA depolymerases (PHAases). Here we describe the synthesis of two new chromogenic compounds derived from polyhydroxyoctanoate (PHO) and their application in a continuous, quantitative spectrophotometric assay for PHO depolymerase and other medium chain lengths PHAase activity within 10 min. These substrates allow activity measurement at temperatures above 45 °C, simplifying the comparison of PHAases and aiding enzymatic degradation progress. The study also explores enzyme specificity and identifies key amino acids involved in PHO recognition by PfPHOase. The 3-hydroxyoctanoyl moieties of both compounds were found to bind specifically to a groove formed by the amino acids Phe96, Phe125, Ile171, and Val230, which are highly conserved in known mcl-PHA depolymerases.
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Affiliation(s)
- Marija Nenadović
- University of Belgrade, Institute of Molecular Genetics and Genetic Engineering, Belgrade, Serbia
| | | | - Sanja Škaro Bogojević
- University of Belgrade, Institute of Molecular Genetics and Genetic Engineering, Belgrade, Serbia
| | - Veselin Maslak
- University of Belgrade, Faculty of Chemistry, Belgrade, Serbia
| | | | - Jelena Milovanović
- University of Belgrade, Institute of Molecular Genetics and Genetic Engineering, Belgrade, Serbia.
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22
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Rezaei Z, Dinani AS, Moghimi H. Cutting-edge developments in plastic biodegradation and upcycling via engineering approaches. Metab Eng Commun 2024; 19:e00256. [PMID: 39687771 PMCID: PMC11647663 DOI: 10.1016/j.mec.2024.e00256] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2024] [Revised: 10/25/2024] [Accepted: 11/27/2024] [Indexed: 12/18/2024] Open
Abstract
The increasing use of plastics has resulted in the production of high quantities of plastic waste that pose a serious risk to the environment. The upcycling of plastics into value-added products offers a potential solution for resolving the plastics environmental crisis. Recently, various microorganisms and their enzymes have been identified for their ability to degrade plastics effectively. Furthermore, many investigations have revealed the application of plastic monomers as carbon sources for bio-upcycling to generate valuable materials such as biosurfactants, bioplastics, and biochemicals. With the advancement in the fields of synthetic biology and metabolic engineering, the construction of high-performance microbes and enzymes for plastic removal and bio-upcycling can be achieved. Plastic valorization can be optimized by improving uptake and conversion efficiency, engineering transporters and enzymes, metabolic pathway reconstruction, and also using a chemo-biological hybrid approach. This review focuses on engineering approaches for enhancing plastic removal and the methods of depolymerization and upcycling processes of various microplastics. Additionally, the major challenges and future perspectives for facilitating the development of a sustainable circular plastic economy are highlighted.
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Affiliation(s)
- Zeinab Rezaei
- Department of Microbiology, School of Biology, College of Science, University of Tehran, Tehran, Iran
| | - Amir Soleimani Dinani
- Department of Microbiology, School of Biology, College of Science, University of Tehran, Tehran, Iran
| | - Hamid Moghimi
- Department of Microbiology, School of Biology, College of Science, University of Tehran, Tehran, Iran
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23
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Shimizu T, Suzuki K, Inui M. A mycofactocin-associated dehydrogenase is essential for ethylene glycol metabolism by Rhodococcus jostii RHA1. Appl Microbiol Biotechnol 2024; 108:58. [PMID: 38175243 DOI: 10.1007/s00253-023-12966-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2023] [Revised: 11/01/2023] [Accepted: 11/13/2023] [Indexed: 01/05/2024]
Abstract
Ethylene glycol is an industrially important diol in many manufacturing processes and a building block of polymers, such as poly(ethylene terephthalate). In this study, we found that a mycolic acid-containing bacterium Rhodococcus jostii RHA1 can grow with ethylene glycol as a sole source of carbon and energy. Deletion of a putative glycolate dehydrogenase gene (RHA1_ro03227) abolished growth with ethylene glycol, indicating that ethylene glycol is assimilated via glycolate in R. jostii RHA1. Transcriptome sequencing and gene deletion analyses revealed that a gene homologous to mycofactocin (MFT)-associated dehydrogenase (RHA1_ro06057), hereafter referred to as EgaA, is essential for ethylene glycol assimilation. Furthermore, egaA deletion also negatively affected the utilization of ethanol, 1-propanol, propylene glycol, and 1-butanol, suggesting that EgaA is involved in the utilization of various alcohols in R. jostii RHA1. Deletion of MFT biosynthetic genes abolished growth with ethylene glycol, indicating that MFT is the physiological electron acceptor of EgaA. Further genetic studies revealed that a putative aldehyde dehydrogenase (RHA1_ro06081) is a major aldehyde dehydrogenase in ethylene glycol metabolism by R. jostii RHA1. KEY POINTS: • Rhodococcus jostii RHA1 can assimilate ethylene glycol via glycolate • A mycofactocin-associated dehydrogenase is involved in the oxidation of ethylene glycol • An aldehyde dehydrogenase gene is important for the ethylene glycol assimilation.
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Affiliation(s)
- Tetsu Shimizu
- Research Institute of Innovative Technology for the Earth, 9-2, Kizugawadai, Kizugawa-Shi, Kyoto, 619-0292, Japan
| | - Kai Suzuki
- Division of Biological Science, Graduate School of Science and Technology, Nara Institute of Science and Technology, 8916-5, Takayama, Ikoma, 630-0192, Japan
| | - Masayuki Inui
- Research Institute of Innovative Technology for the Earth, 9-2, Kizugawadai, Kizugawa-Shi, Kyoto, 619-0292, Japan.
- Division of Biological Science, Graduate School of Science and Technology, Nara Institute of Science and Technology, 8916-5, Takayama, Ikoma, 630-0192, Japan.
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24
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Roccor R, Wolf ME, Liu J, Eltis LD. The catabolism of ethylene glycol by Rhodococcus jostii RHA1 and its dependence on mycofactocin. Appl Environ Microbiol 2024; 90:e0041624. [PMID: 38837369 PMCID: PMC11267921 DOI: 10.1128/aem.00416-24] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2024] [Accepted: 05/14/2024] [Indexed: 06/07/2024] Open
Abstract
Ethylene glycol (EG) is a widely used industrial chemical with manifold applications and also generated in the degradation of plastics such as polyethylene terephthalate. Rhodococcus jostii RHA1 (RHA1), a potential biocatalytic chassis, grows on EG. Transcriptomic analyses revealed four clusters of genes potentially involved in EG catabolism: the mad locus, predicted to encode mycofactocin-dependent alcohol degradation, including the catabolism of EG to glycolate; two GCL clusters, predicted to encode glycolate and glyoxylate catabolism; and the mft genes, predicted to specify mycofactocin biosynthesis. Bioinformatic analyses further revealed that the mad and mft genes are widely distributed in mycolic acid-producing bacteria such as RHA1. Neither ΔmadA nor ΔmftC RHA1 mutant strains grew on EG but grew on acetate. In resting cell assays, the ΔmadA mutant depleted glycolaldehyde but not EG from culture media. These results indicate that madA encodes a mycofactocin-dependent alcohol dehydrogenase that initiates EG catabolism. In contrast to some mycobacterial strains, the mad genes did not appear to enable RHA1 to grow on methanol as sole substrate. Finally, a strain of RHA1 adapted to grow ~3× faster on EG contained an overexpressed gene, aldA2, predicted to encode an aldehyde dehydrogenase. When incubated with EG, this strain accumulated lower concentrations of glycolaldehyde than RHA1. Moreover, ecotopically expressed aldA2 increased RHA1's tolerance for EG further suggesting that glycolaldehyde accumulation limits growth of RHA1 on EG. Overall, this study provides insights into the bacterial catabolism of small alcohols and aldehydes and facilitates the engineering of Rhodococcus for the upgrading of plastic waste streams.IMPORTANCEEthylene glycol (EG), a two-carbon (C2) alcohol, is produced in high volumes for use in a wide variety of applications. There is burgeoning interest in understanding and engineering the bacterial catabolism of EG, in part to establish circular economic routes for its use. This study identifies an EG catabolic pathway in Rhodococcus, a genus of bacteria well suited for biocatalysis. This pathway is responsible for the catabolism of methanol, a C1 feedstock, in related bacteria. Finally, we describe strategies to increase the rate of degradation of EG by increasing the transformation of glycolaldehyde, a toxic metabolic intermediate. This work advances the development of biocatalytic strategies to transform C2 feedstocks.
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Affiliation(s)
- Raphael Roccor
- Department of Microbiology and Immunology, Life Sciences Institute, The University of British Columbia, Vancouver, British Columbia, Canada
| | - Megan E. Wolf
- Department of Microbiology and Immunology, Life Sciences Institute, The University of British Columbia, Vancouver, British Columbia, Canada
| | - Jie Liu
- Department of Microbiology and Immunology, Life Sciences Institute, The University of British Columbia, Vancouver, British Columbia, Canada
| | - Lindsay D. Eltis
- Department of Microbiology and Immunology, Life Sciences Institute, The University of British Columbia, Vancouver, British Columbia, Canada
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25
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Klauer RR, Hansen DA, Wu D, Monteiro LMO, Solomon KV, Blenner MA. Biological Upcycling of Plastics Waste. Annu Rev Chem Biomol Eng 2024; 15:315-342. [PMID: 38621232 PMCID: PMC11575423 DOI: 10.1146/annurev-chembioeng-100522-115850] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/17/2024]
Abstract
Plastic wastes accumulate in the environment, impacting wildlife and human health and representing a significant pool of inexpensive waste carbon that could form feedstock for the sustainable production of commodity chemicals, monomers, and specialty chemicals. Current mechanical recycling technologies are not economically attractive due to the lower-quality plastics that are produced in each iteration. Thus, the development of a plastics economy requires a solution that can deconstruct plastics and generate value from the deconstruction products. Biological systems can provide such value by allowing for the processing of mixed plastics waste streams via enzymatic specificity and using engineered metabolic pathways to produce upcycling targets. We focus on the use of biological systems for waste plastics deconstruction and upcycling. We highlight documented and predicted mechanisms through which plastics are biologically deconstructed and assimilated and provide examples of upcycled products from biological systems. Additionally, we detail current challenges in the field, including the discovery and development of microorganisms and enzymes for deconstructing non-polyethylene terephthalate plastics, the selection of appropriate target molecules to incentivize development of a plastic bioeconomy, and the selection of microbial chassis for the valorization of deconstruction products.
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Affiliation(s)
- Ross R Klauer
- Department of Chemical and Biomolecular Engineering, University of Delaware, Newark, Delaware, USA; ,
| | - D Alex Hansen
- Department of Chemical and Biomolecular Engineering, University of Delaware, Newark, Delaware, USA; ,
| | - Derek Wu
- Department of Chemical and Biomolecular Engineering, University of Delaware, Newark, Delaware, USA; ,
| | | | - Kevin V Solomon
- Department of Chemical and Biomolecular Engineering, University of Delaware, Newark, Delaware, USA; ,
| | - Mark A Blenner
- Department of Chemical and Biomolecular Engineering, University of Delaware, Newark, Delaware, USA; ,
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26
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Liu R, Xu H, Zhao S, Dong C, Li J, Wei G, Li G, Gong L, Yan P, Shao Z. Polyethylene terephthalate (PET)-degrading bacteria in the pelagic deep-sea sediments of the Pacific Ocean. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2024; 352:124131. [PMID: 38734049 DOI: 10.1016/j.envpol.2024.124131] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/08/2024] [Revised: 05/06/2024] [Accepted: 05/08/2024] [Indexed: 05/13/2024]
Abstract
Polyethylene terephthalate (PET) plastic pollution is widely found in deep-sea sediments. Despite being an international environmental issue, it remains unclear whether PET can be degraded through bioremediation in the deep sea. Pelagic sediments obtained from 19 sites across a wide geographic range in the Pacific Ocean were used to screen for bacteria with PET degrading potential. Bacterial consortia that could grow on PET as the sole carbon and energy source were found in 10 of the 19 sites. These bacterial consortia showed PET removal rate of 1.8%-16.2% within two months, which was further confirmed by the decrease of carbonyl and aliphatic hydrocarbon groups using attenuated total reflectance-Fourier-transform infrared analysis (ATR-FTIR). Analysis of microbial diversity revealed that Alcanivorax and Pseudomonas were predominant in all 10 PET degrading consortia. Meanwhile, Thalassospira, Nitratireductor, Nocardioides, Muricauda, and Owenweeksia were also found to possess PET degradation potential. Metabolomic analysis showed that Alcanivorax sp. A02-7 and Pseudomonas sp. A09-2 could turn PET into mono-(2-hydroxyethyl) terephthalate (MHET) even in situ stimulation (40 MPa, 10 °C) conditions. These findings widen the currently knowledge of deep-sea PET biodegrading process with bacteria isolates and degrading mechanisms, and indicating that the marine environment is a source of biotechnologically promising bacterial isolates and enzymes.
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Affiliation(s)
- Renju Liu
- Key Laboratory of Marine Genetic Resources, Third Institute of Oceanography, Ministry of Natural Resources of China, State Key Laboratory Breeding Base of Marine Genetic Resources, Fujian Key Laboratory of Marine Genetic Resources, Xiamen 361005, China; School of Environmental Science, Harbin Institute of Technology, Harbin 150090, China
| | - Haiming Xu
- Key Laboratory of Marine Genetic Resources, Third Institute of Oceanography, Ministry of Natural Resources of China, State Key Laboratory Breeding Base of Marine Genetic Resources, Fujian Key Laboratory of Marine Genetic Resources, Xiamen 361005, China
| | - Sufang Zhao
- Key Laboratory of Marine Genetic Resources, Third Institute of Oceanography, Ministry of Natural Resources of China, State Key Laboratory Breeding Base of Marine Genetic Resources, Fujian Key Laboratory of Marine Genetic Resources, Xiamen 361005, China
| | - Chunming Dong
- Key Laboratory of Marine Genetic Resources, Third Institute of Oceanography, Ministry of Natural Resources of China, State Key Laboratory Breeding Base of Marine Genetic Resources, Fujian Key Laboratory of Marine Genetic Resources, Xiamen 361005, China
| | - Jianyang Li
- Key Laboratory of Marine Genetic Resources, Third Institute of Oceanography, Ministry of Natural Resources of China, State Key Laboratory Breeding Base of Marine Genetic Resources, Fujian Key Laboratory of Marine Genetic Resources, Xiamen 361005, China
| | - Guangshan Wei
- Key Laboratory of Marine Genetic Resources, Third Institute of Oceanography, Ministry of Natural Resources of China, State Key Laboratory Breeding Base of Marine Genetic Resources, Fujian Key Laboratory of Marine Genetic Resources, Xiamen 361005, China
| | - Guangyu Li
- Key Laboratory of Marine Genetic Resources, Third Institute of Oceanography, Ministry of Natural Resources of China, State Key Laboratory Breeding Base of Marine Genetic Resources, Fujian Key Laboratory of Marine Genetic Resources, Xiamen 361005, China
| | - Linfeng Gong
- Key Laboratory of Marine Genetic Resources, Third Institute of Oceanography, Ministry of Natural Resources of China, State Key Laboratory Breeding Base of Marine Genetic Resources, Fujian Key Laboratory of Marine Genetic Resources, Xiamen 361005, China
| | - Peisheng Yan
- School of Environmental Science, Harbin Institute of Technology, Harbin 150090, China
| | - Zongze Shao
- Key Laboratory of Marine Genetic Resources, Third Institute of Oceanography, Ministry of Natural Resources of China, State Key Laboratory Breeding Base of Marine Genetic Resources, Fujian Key Laboratory of Marine Genetic Resources, Xiamen 361005, China; School of Environmental Science, Harbin Institute of Technology, Harbin 150090, China; Laboratory for Marine Biology and Biotechnology, Pilot National Laboratory for Marine Science and Technology (Qingdao), China.
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27
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Chang CT, Kuo KC, Ho JH, Lee LR, Gautam B, Ciou JH, Tseng YH, Chang CW, Wu CT, Lin CT, Chen JT. Reversible Sensing Technologies Using Upcycled TPEE: Crafting pH and Light Responsive Materials towards Sustainable Monitoring. SMALL (WEINHEIM AN DER BERGSTRASSE, GERMANY) 2024; 20:e2400491. [PMID: 38456574 DOI: 10.1002/smll.202400491] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/22/2024] [Revised: 02/23/2024] [Indexed: 03/09/2024]
Abstract
Multiresponsive materials with reversible and durable characteristics are indispensable because of their promising applications in environmental change detections. To fabricate multiresponsive materials in mass production, however, complex reactions and impractical situations are often involved. Herein, a dual responsive (light and pH) spiropyran-based smart sensor fabricated by a simple layer-by-layer (LbL) assembly process from upcycled thermoplastic polyester elastomer (TPEE) materials derived from recycled polyethylene terephthalate (r-PET) is proposed. Positively charged chitosan solutions and negatively charged merocyanine-COOH (MC-COOH) solutions are employed in the LbL assembly technique, forming the chitosan-spiropyran deposited TPEE (TPEE-CH-SP) film. Upon UV irradiation, the spiropyran-COOH (SP-COOH) molecules on the TPEE-CH-SP film undergo the ring-opening isomerization, along with an apparent color change from colorless to purple, to transform into the MC-COOH molecules. By further exposing the TPEE-CH-MC film to hydrogen chloride (HCl) and nitric acid (HNO3) vapors, the MC-COOH molecules can be transformed into protonated merocyanine-COOH (MCH-COOH) with the simultaneous color change from purple to yellow.
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Affiliation(s)
- Chun-Ting Chang
- Department of Applied Chemistry, National Yang Ming Chiao Tung University, Hsinchu, 300093, Taiwan
| | - Kai-Chuan Kuo
- Department of Applied Chemistry, National Yang Ming Chiao Tung University, Hsinchu, 300093, Taiwan
- Department of Performance Materials Synthesis & Application Division of Polymer Research Material and Chemical Research Laboratories, Industrial Technology Research Institute, Hsinchu, 300044, Taiwan
| | - Jhih-Hao Ho
- Department of Applied Chemistry, National Yang Ming Chiao Tung University, Hsinchu, 300093, Taiwan
| | - Lin-Ruei Lee
- Department of Applied Chemistry, National Yang Ming Chiao Tung University, Hsinchu, 300093, Taiwan
| | - Bhaskarchand Gautam
- Department of Applied Chemistry, National Yang Ming Chiao Tung University, Hsinchu, 300093, Taiwan
| | - Jian-Hua Ciou
- Department of Applied Chemistry, National Yang Ming Chiao Tung University, Hsinchu, 300093, Taiwan
| | - Yu-Hsuan Tseng
- Department of Applied Chemistry, National Yang Ming Chiao Tung University, Hsinchu, 300093, Taiwan
| | - Chia-Wei Chang
- Department of Applied Chemistry, National Yang Ming Chiao Tung University, Hsinchu, 300093, Taiwan
| | - Chia-Ti Wu
- Department of Applied Chemistry, National Yang Ming Chiao Tung University, Hsinchu, 300093, Taiwan
| | - Che-Tseng Lin
- Department of Performance Materials Synthesis & Application Division of Polymer Research Material and Chemical Research Laboratories, Industrial Technology Research Institute, Hsinchu, 300044, Taiwan
| | - Jiun-Tai Chen
- Department of Applied Chemistry, National Yang Ming Chiao Tung University, Hsinchu, 300093, Taiwan
- Center for Emergent Functional Matter Science, National Yang Ming Chiao Tung University, Hsinchu, 300093, Taiwan
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28
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Enache AC, Grecu I, Samoila P. Polyethylene Terephthalate (PET) Recycled by Catalytic Glycolysis: A Bridge toward Circular Economy Principles. MATERIALS (BASEL, SWITZERLAND) 2024; 17:2991. [PMID: 38930360 PMCID: PMC11205646 DOI: 10.3390/ma17122991] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/20/2024] [Revised: 06/13/2024] [Accepted: 06/14/2024] [Indexed: 06/28/2024]
Abstract
Plastic pollution has escalated into a critical global issue, with production soaring from 2 million metric tons in 1950 to 400.3 million metric tons in 2022. The packaging industry alone accounts for nearly 44% of this production, predominantly utilizing polyethylene terephthalate (PET). Alarmingly, over 90% of the approximately 1 million PET bottles sold every minute end up in landfills or oceans, where they can persist for centuries. This highlights the urgent need for sustainable management and recycling solutions to mitigate the environmental impact of PET waste. To better understand PET's behavior and promote its management within a circular economy, we examined its chemical and physical properties, current strategies in the circular economy, and the most effective recycling methods available today. Advancing PET management within a circular economy framework by closing industrial loops has demonstrated benefits such as reduced landfill waste, minimized energy consumption, and conserved raw resources. To this end, we identified and examined various strategies based on R-imperatives (ranging from 3R to 10R), focusing on the latest approaches aimed at significantly reducing PET waste by 2040. Additionally, a comparison of PET recycling methods (including primary, secondary, tertiary, and quaternary recycling, along with the concepts of "zero-order" and biological recycling techniques) was envisaged. Particular attention was paid to the heterogeneous catalytic glycolysis, which stands out for its rapid reaction time (20-60 min), high monomer yields (>90%), ease of catalyst recovery and reuse, lower costs, and enhanced durability. Accordingly, the use of highly efficient oxide-based catalysts for PET glycolytic degradation is underscored as a promising solution for large-scale industrial applications.
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Affiliation(s)
| | | | - Petrisor Samoila
- “Petru Poni” Institute of Macromolecular Chemistry, 41A Grigore Ghica Voda Alley, 700487 Iasi, Romania; (A.-C.E.); (I.G.)
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29
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Shimizu T, Inui M. Novel aspects of ethylene glycol catabolism. Appl Microbiol Biotechnol 2024; 108:369. [PMID: 38861200 PMCID: PMC11166783 DOI: 10.1007/s00253-024-13179-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2024] [Revised: 05/02/2024] [Accepted: 05/10/2024] [Indexed: 06/12/2024]
Abstract
Ethylene glycol (EG) is an industrially important two-carbon diol used as a solvent, antifreeze agent, and building block of polymers such as poly(ethylene terephthalate) (PET). Recently, the use of EG as a starting material for the production of bio-fuels or bio-chemicals is gaining attention as a sustainable process since EG can be derived from materials not competing with human food stocks including CO2, syngas, lignocellulolytic biomass, and PET waste. In order to design and construct microbial process for the conversion of EG to value-added chemicals, microbes capable of catabolizing EG such as Escherichia coli, Pseudomonas putida, Rhodococcus jostii, Ideonella sakaiensis, Paracoccus denitrificans, and Acetobacterium woodii are candidates of chassis for the construction of synthetic pathways. In this mini-review, we describe EG catabolic pathways and catabolic enzymes in these microbes, and further review recent advances in microbial conversion of EG to value-added chemicals by means of metabolic engineering. KEY POINTS: • Ethylene glycol is a potential next-generation feedstock for sustainable industry. • Microbial conversion of ethylene glycol to value-added chemicals is gaining attention. • Ethylene glycol-utilizing microbes are useful as chassis for synthetic pathways.
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Affiliation(s)
- Tetsu Shimizu
- Research Institute of Innovative Technology for the Earth, 9-2, Kizugawadai, Kizugawa-shi, Kyoto, 619-0292, Japan
| | - Masayuki Inui
- Research Institute of Innovative Technology for the Earth, 9-2, Kizugawadai, Kizugawa-shi, Kyoto, 619-0292, Japan.
- Division of Biological Science, Graduate School of Science and Technology, Nara Institute of Science and Technology, 8916-5 Takayama, Ikoma, 630-0192, Japan.
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30
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Yang J, Li Z, Xu Q, Liu W, Gao S, Qin P, Chen Z, Wang A. Towards carbon neutrality: Sustainable recycling and upcycling strategies and mechanisms for polyethylene terephthalate via biotic/abiotic pathways. ECO-ENVIRONMENT & HEALTH 2024; 3:117-130. [PMID: 38638172 PMCID: PMC11021832 DOI: 10.1016/j.eehl.2024.01.010] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/11/2023] [Revised: 01/09/2024] [Accepted: 01/25/2024] [Indexed: 04/20/2024]
Abstract
Polyethylene terephthalate (PET), one of the most ubiquitous engineering plastics, presents both environmental challenges and opportunities for carbon neutrality and a circular economy. This review comprehensively addressed the latest developments in biotic and abiotic approaches for PET recycling/upcycling. Biotically, microbial depolymerization of PET, along with the biosynthesis of reclaimed monomers [terephthalic acid (TPA), ethylene glycol (EG)] to value-added products, presents an alternative for managing PET waste and enables CO2 reduction. Abiotically, thermal treatments (i.e., hydrolysis, glycolysis, methanolysis, etc.) and photo/electrocatalysis, enabled by catalysis advances, can depolymerize or convert PET/PET monomers in a more flexible, simple, fast, and controllable manner. Tandem abiotic/biotic catalysis offers great potential for PET upcycling to generate commodity chemicals and alternative materials, ideally at lower energy inputs, greenhouse gas emissions, and costs, compared to virgin polymer fabrication. Remarkably, over 25 types of upgraded PET products (e.g., adipic acid, muconic acid, catechol, vanillin, and glycolic acid, etc.) have been identified, underscoring the potential of PET upcycling in diverse applications. Efforts can be made to develop chemo-catalytic depolymerization of PET, improve microbial depolymerization of PET (e.g., hydrolysis efficiency, enzymatic activity, thermal and pH level stability, etc.), as well as identify new microorganisms or hydrolases capable of degrading PET through computational and machine learning algorithms. Consequently, this review provides a roadmap for advancing PET recycling and upcycling technologies, which hold the potential to shape the future of PET waste management and contribute to the preservation of our ecosystems.
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Affiliation(s)
- Jiaqi Yang
- School of Civil & Environmental Engineering, Harbin Institute of Technology (Shenzhen), Shenzhen 518055, China
| | - Zhiling Li
- State Key Laboratory of Urban Water Resources and Environment, School of Environment, Harbin Institute of Technology, Harbin 150090, China
| | - Qiongying Xu
- School of Civil & Environmental Engineering, Harbin Institute of Technology (Shenzhen), Shenzhen 518055, China
| | - Wenzong Liu
- School of Civil & Environmental Engineering, Harbin Institute of Technology (Shenzhen), Shenzhen 518055, China
| | - Shuhong Gao
- School of Civil & Environmental Engineering, Harbin Institute of Technology (Shenzhen), Shenzhen 518055, China
| | - Peiwu Qin
- Institute of Biopharmaceutical and Health Engineering, Shenzhen International Graduate School, Tsinghua University, Shenzhen 518055, China
- Tsinghua-Berkeley Shenzhen Institute, Tsinghua Shenzhen International Graduate School, Tsinghua University, Shenzhen 518055, China
| | - Zhenglin Chen
- Institute of Biopharmaceutical and Health Engineering, Shenzhen International Graduate School, Tsinghua University, Shenzhen 518055, China
- Tsinghua-Berkeley Shenzhen Institute, Tsinghua Shenzhen International Graduate School, Tsinghua University, Shenzhen 518055, China
| | - Aijie Wang
- School of Civil & Environmental Engineering, Harbin Institute of Technology (Shenzhen), Shenzhen 518055, China
- State Key Laboratory of Urban Water Resources and Environment, School of Environment, Harbin Institute of Technology, Harbin 150090, China
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31
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Yan ZF, Feng CQ, Chen XQ, Jin CX, Xia W, Chen S, Wu J. Design and construction of chemical-biological module clusters for degradation and assimilation of poly(ethylene terephthalate) waste. JOURNAL OF ENVIRONMENTAL MANAGEMENT 2024; 361:121258. [PMID: 38815428 DOI: 10.1016/j.jenvman.2024.121258] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/27/2023] [Revised: 04/11/2024] [Accepted: 05/25/2024] [Indexed: 06/01/2024]
Abstract
The rising accumulation of poly(ethylene terephthalate) (PET) waste presents an urgent ecological challenge, necessitating an efficient and economical treatment technology. Here, we developed chemical-biological module clusters that perform chemical pretreatment, enzymatic degradation, and microbial assimilation for the large-scale treatment of PET waste. This module cluster included (i) a chemical pretreatment that involves incorporating polycaprolactone (PCL) at a weight ratio of 2% (PET:PCL = 98:2) into PET via mechanical blending, which effectively reduces the crystallinity and enhances degradation; (ii) enzymatic degradation using Thermobifida fusca cutinase variant (4Mz), that achieves complete degradation of pretreated PET at 300 g/L PET, with an enzymatic loading of 1 mg protein per gram of PET; and (iii) microbial assimilation, where Rhodococcus jostii RHA1 metabolizes the degradation products, assimilating each monomer at a rate above 90%. A comparative life cycle assessment demonstrated that the carbon emissions from our module clusters (0.25 kg CO2-eq/kg PET) are lower than those from other established approaches. This study pioneers a closed-loop system that seamlessly incorporates pretreatment, degradation, and assimilation processes, thus mitigating the environmental impacts of PET waste and propelling the development of a circular PET economy.
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Affiliation(s)
- Zheng-Fei Yan
- School of Biotechnology and Key Laboratory of Industrial Biotechnology Ministry of Education, Jiangnan University, 1800 Lihu Avenue, Wuxi, 214122, China; International Joint Laboratory on Food Safety, Jiangnan University, 1800 Lihu Avenue, Wuxi, 214122, China.
| | - Chu-Qi Feng
- School of Biotechnology and Key Laboratory of Industrial Biotechnology Ministry of Education, Jiangnan University, 1800 Lihu Avenue, Wuxi, 214122, China; International Joint Laboratory on Food Safety, Jiangnan University, 1800 Lihu Avenue, Wuxi, 214122, China
| | - Xiao-Qian Chen
- School of Biotechnology and Key Laboratory of Industrial Biotechnology Ministry of Education, Jiangnan University, 1800 Lihu Avenue, Wuxi, 214122, China; International Joint Laboratory on Food Safety, Jiangnan University, 1800 Lihu Avenue, Wuxi, 214122, China
| | - Chang-Xu Jin
- School of Biotechnology and Key Laboratory of Industrial Biotechnology Ministry of Education, Jiangnan University, 1800 Lihu Avenue, Wuxi, 214122, China; International Joint Laboratory on Food Safety, Jiangnan University, 1800 Lihu Avenue, Wuxi, 214122, China
| | - Wei Xia
- School of Biotechnology and Key Laboratory of Industrial Biotechnology Ministry of Education, Jiangnan University, 1800 Lihu Avenue, Wuxi, 214122, China; International Joint Laboratory on Food Safety, Jiangnan University, 1800 Lihu Avenue, Wuxi, 214122, China
| | - Sheng Chen
- School of Biotechnology and Key Laboratory of Industrial Biotechnology Ministry of Education, Jiangnan University, 1800 Lihu Avenue, Wuxi, 214122, China; International Joint Laboratory on Food Safety, Jiangnan University, 1800 Lihu Avenue, Wuxi, 214122, China
| | - Jing Wu
- School of Biotechnology and Key Laboratory of Industrial Biotechnology Ministry of Education, Jiangnan University, 1800 Lihu Avenue, Wuxi, 214122, China; International Joint Laboratory on Food Safety, Jiangnan University, 1800 Lihu Avenue, Wuxi, 214122, China.
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32
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Moon TS. Earth: Extinguishing anthropogenic risks through harmonization. N Biotechnol 2024; 80:69-71. [PMID: 38367910 PMCID: PMC10939714 DOI: 10.1016/j.nbt.2024.02.002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2024] [Revised: 02/05/2024] [Accepted: 02/10/2024] [Indexed: 02/19/2024]
Abstract
Human diseases can kill one person at a time, but the COVID-19 pandemic showed massacres could be possible. The climate crisis could be even worse, potentially leading to a bigger number of deaths of the human species and all living systems on Earth. I urge us to change our human-focused mindset to solve many problems, including the climate crisis, which humans caused to the entire ecosystems due to our arrogance: humans own this world. In this perspective article, I propose four recommendations to address climate issues through paradigm change and safe and sustainable technologies.
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Affiliation(s)
- Tae Seok Moon
- Department of Energy, Environmental and Chemical Engineering, Washington University in St. Louis, St. Louis, MO, USA.
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33
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Martín-González D, de la Fuente Tagarro C, De Lucas A, Bordel S, Santos-Beneit F. Genetic Modifications in Bacteria for the Degradation of Synthetic Polymers: A Review. Int J Mol Sci 2024; 25:5536. [PMID: 38791573 PMCID: PMC11121894 DOI: 10.3390/ijms25105536] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2024] [Revised: 05/07/2024] [Accepted: 05/17/2024] [Indexed: 05/26/2024] Open
Abstract
Synthetic polymers, commonly known as plastics, are currently present in all aspects of our lives. Although they are useful, they present the problem of what to do with them after their lifespan. There are currently mechanical and chemical methods to treat plastics, but these are methods that, among other disadvantages, can be expensive in terms of energy or produce polluting gases. A more environmentally friendly alternative is recycling, although this practice is not widespread. Based on the practice of the so-called circular economy, many studies are focused on the biodegradation of these polymers by enzymes. Using enzymes is a harmless method that can also generate substances with high added value. Novel and enhanced plastic-degrading enzymes have been obtained by modifying the amino acid sequence of existing ones, especially on their active site, using a wide variety of genetic approaches. Currently, many studies focus on the common aim of achieving strains with greater hydrolytic activity toward a different range of plastic polymers. Although in most cases the depolymerization rate is improved, more research is required to develop effective biodegradation strategies for plastic recycling or upcycling. This review focuses on a compilation and discussion of the most important research outcomes carried out on microbial biotechnology to degrade and recycle plastics.
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Affiliation(s)
- Diego Martín-González
- Department of Chemical Engineering and Environmental Technology, School of Industrial Engineering, University of Valladolid, Dr. Mergelina, s/n, 47011 Valladolid, Spain; (D.M.-G.); (A.D.L.); (S.B.)
| | - Carlos de la Fuente Tagarro
- Department of Chemical Engineering and Environmental Technology, School of Industrial Engineering, University of Valladolid, Dr. Mergelina, s/n, 47011 Valladolid, Spain; (D.M.-G.); (A.D.L.); (S.B.)
| | - Andrea De Lucas
- Department of Chemical Engineering and Environmental Technology, School of Industrial Engineering, University of Valladolid, Dr. Mergelina, s/n, 47011 Valladolid, Spain; (D.M.-G.); (A.D.L.); (S.B.)
| | - Sergio Bordel
- Department of Chemical Engineering and Environmental Technology, School of Industrial Engineering, University of Valladolid, Dr. Mergelina, s/n, 47011 Valladolid, Spain; (D.M.-G.); (A.D.L.); (S.B.)
- Institute of Sustainable Processes, Dr. Mergelina s/n, 47011 Valladolid, Spain
| | - Fernando Santos-Beneit
- Department of Chemical Engineering and Environmental Technology, School of Industrial Engineering, University of Valladolid, Dr. Mergelina, s/n, 47011 Valladolid, Spain; (D.M.-G.); (A.D.L.); (S.B.)
- Institute of Sustainable Processes, Dr. Mergelina s/n, 47011 Valladolid, Spain
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34
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Weiland F, Kohlstedt M, Wittmann C. Biobased de novo synthesis, upcycling, and recycling - the heartbeat toward a green and sustainable polyethylene terephthalate industry. Curr Opin Biotechnol 2024; 86:103079. [PMID: 38422776 DOI: 10.1016/j.copbio.2024.103079] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2023] [Revised: 01/19/2024] [Accepted: 01/24/2024] [Indexed: 03/02/2024]
Abstract
Polyethylene terephthalate (PET) has revolutionized the industrial sector because of its versatility, with its predominant uses in the textiles and packaging materials industries. Despite the various advantages of this polymer, its synthesis is, unfavorably, tightly intertwined with nonrenewable fossil resources. Additionally, given its widespread use, accumulating PET waste poses a significant environmental challenge. As a result, current research in the areas of biological recycling, upcycling, and de novo synthesis is intensifying. Biological recycling involves the use of micro-organisms or enzymes to breakdown PET into monomers, offering a sustainable alternative to traditional recycling. Upcycling transforms PET waste into value-added products, expanding its potential application range and promoting a circular economy. Moreover, studies of cascading biological and chemical processes driven by microbial cell factories have explored generating PET using renewable, biobased feedstocks such as lignin. These avenues of research promise to mitigate the environmental footprint of PET, underlining the importance of sustainable innovations in the industry.
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Affiliation(s)
- Fabia Weiland
- Institute of Systems Biotechnology, Saarland University, Germany
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35
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Kumar V, Sharma N, Umesh M, Sharma R, Sharma M, Sharma D, Sharma M, Sondhi S, Thomas J, Kumar D, Kansal L, Jha NK. Commercialization potential of PET (polyethylene terephthalate) recycled nanomaterials: A review on validation parameters. CHEMOSPHERE 2024; 352:141453. [PMID: 38364916 DOI: 10.1016/j.chemosphere.2024.141453] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/18/2023] [Revised: 01/10/2024] [Accepted: 02/10/2024] [Indexed: 02/18/2024]
Abstract
Polyethylene Terephthalate (PET) is a polymer which is considered as one of the major contaminants to the environment. The PET waste materials can be recycled to produce value-added products. PET can be converted to nanoparticles, nanofibers, nanocomposites, and nano coatings. To extend the applications of PET nanomaterials, understanding its commercialization potential is important. In addition, knowledge about the factors affecting recycling of PET based nanomaterials is essential. The presented review is focused on understanding the PET commercialization aspects, keeping in mind market analysis, growth drivers, regulatory affairs, safety considerations, issues associated with scale-up, manufacturing challenges, economic viability, and cost-effectiveness. In addition, the paper elaborates the challenges associated with the use of PET based nanomaterials. These challenges include PET contamination to water, soil, sediments, and human exposure to PET nanomaterials. Moreover, the paper discusses in detail about the factors affecting PET recycling, commercialization, and circular economy with specific emphasis on life cycle assessment (LCA) of PET recycled nanomaterials.
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Affiliation(s)
- Vinay Kumar
- Bioconversion and Tissue Engineering (BITE) Laboratory, Department of Community Medicine, Saveetha Medical College and Hospital, Saveetha Institute of Medical and Technical Sciences (SIMATS), Chennai, Thandalam, 602105, India
| | - Neha Sharma
- Department of Biochemistry, Saveetha Medical College and Hospital, Saveetha Institute of Medical and Technical Sciences (SIMATS), Chennai, Thandalam, 602105, India
| | - Mridul Umesh
- Department of Life Sciences, CHRIST (Deemed to be University), Bangalore, 560029, Karnataka, India.
| | - Roopali Sharma
- Department of Biotechnology, Chandigarh College of Technology, Chandigarh Group of Colleges, Landran, Mohali, 140307, Punjab, India
| | - Munish Sharma
- Department of Plant Sciences, Central University of Himachal Pradesh, Shahpur Campus, 176206, Kangra, Himachal Pradesh, India
| | - Deepak Sharma
- Department of Biotechnology, Chandigarh College of Technology, Chandigarh Group of Colleges, Landran, Mohali, 140307, Punjab, India
| | - Munish Sharma
- Department of Plant Sciences, Central University of Himachal Pradesh, Shahpur Campus, 176206, Kangra, Himachal Pradesh, India
| | - Sonica Sondhi
- Haryana State Pollution Control Board, C-11, Panchkula, Haryana, India
| | - Jithin Thomas
- Department of Biotechnology, Mar Athanasius College, Kerala, India
| | - Deepak Kumar
- Department of Biotechnology-UIBT, Chandigarh University, Punjab, India
| | - Lavish Kansal
- School of Electronics and Electrical Engineering, Lovely Professional University, Phagwara, India
| | - Niraj Kumar Jha
- Centre for Global Health Research, Saveetha Medical College, Saveetha Institute of Medical and Technical Sciences, Saveetha University, Chennai, India; Centre for Research Impact and Outcomes, Chitkara University, Rajpura, Punjab, India; Department of Biotechnology, School of Applied & Life Sciences (SALS), Uttaranchal University, Dehradun, 248007, India
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36
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Amalia L, Chang CY, Wang SSS, Yeh YC, Tsai SL. Recent advances in the biological depolymerization and upcycling of polyethylene terephthalate. Curr Opin Biotechnol 2024; 85:103053. [PMID: 38128200 DOI: 10.1016/j.copbio.2023.103053] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2023] [Revised: 11/16/2023] [Accepted: 11/28/2023] [Indexed: 12/23/2023]
Abstract
Polyethylene terephthalate (PET) is favored for its exceptional properties and widespread daily use. This review highlights recent advancements that enable the development of biological tools for PET decomposition, transforming PET into valuable platform chemicals and materials in upcycling processes. Enhancing PET hydrolases' catalytic activity and efficiency through protein engineering strategies is a priority, facilitating more effective PET waste management. Efforts to create novel PET hydrolases for large-scale PET depolymerization continue, but cost-effectiveness remains challenging. Hydrolyzed monomers must add additional value to make PET recycling economically attractive. Valorization of hydrolysis products through the upcycling process is expected to produce new compounds with different values and qualities from the initial polymer, making the decomposed monomers more appealing. Advances in synthetic biology and enzyme engineering hold promise for PET upcycling. While biological depolymerization offers environmental benefits, further research is needed to make PET upcycling sustainable and economically feasible.
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Affiliation(s)
- Lita Amalia
- Department of Chemical Engineering, National Taiwan University of Science and Technology, Taipei 10607, Taiwan
| | - Chia-Yu Chang
- Department of Chemical Engineering, National Taiwan University, Taipei 10617, Taiwan
| | - Steven S-S Wang
- Department of Chemical Engineering, National Taiwan University, Taipei 10617, Taiwan
| | - Yi-Chun Yeh
- Department of Chemistry, National Taiwan Normal University, Taipei 11677, Taiwan
| | - Shen-Long Tsai
- Department of Chemical Engineering, National Taiwan University of Science and Technology, Taipei 10607, Taiwan.
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37
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Lv S, Li Y, Zhao S, Shao Z. Biodegradation of Typical Plastics: From Microbial Diversity to Metabolic Mechanisms. Int J Mol Sci 2024; 25:593. [PMID: 38203764 PMCID: PMC10778777 DOI: 10.3390/ijms25010593] [Citation(s) in RCA: 21] [Impact Index Per Article: 21.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2023] [Revised: 12/22/2023] [Accepted: 12/27/2023] [Indexed: 01/12/2024] Open
Abstract
Plastic production has increased dramatically, leading to accumulated plastic waste in the ocean. Marine plastics can be broken down into microplastics (<5 mm) by sunlight, machinery, and pressure. The accumulation of microplastics in organisms and the release of plastic additives can adversely affect the health of marine organisms. Biodegradation is one way to address plastic pollution in an environmentally friendly manner. Marine microorganisms can be more adapted to fluctuating environmental conditions such as salinity, temperature, pH, and pressure compared with terrestrial microorganisms, providing new opportunities to address plastic pollution. Pseudomonadota (Proteobacteria), Bacteroidota (Bacteroidetes), Bacillota (Firmicutes), and Cyanobacteria were frequently found on plastic biofilms and may degrade plastics. Currently, diverse plastic-degrading bacteria are being isolated from marine environments such as offshore and deep oceanic waters, especially Pseudomonas spp. Bacillus spp. Alcanivoras spp. and Actinomycetes. Some marine fungi and algae have also been revealed as plastic degraders. In this review, we focused on the advances in plastic biodegradation by marine microorganisms and their enzymes (esterase, cutinase, laccase, etc.) involved in the process of biodegradation of polyethylene terephthalate (PET), polystyrene (PS), polyethylene (PE), polyvinyl chloride (PVC), and polypropylene (PP) and highlighted the need to study plastic biodegradation in the deep sea.
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Affiliation(s)
- Shiwei Lv
- Key Laboratory of Marine Genetic Resources, Third Institute of Oceanography, Ministry of Natural Resources of China, Xiamen 361005, China; (S.L.); (Y.L.); (S.Z.)
- School of Environmental Science, Harbin Institute of Technology, Harbin 150090, China
| | - Yufei Li
- Key Laboratory of Marine Genetic Resources, Third Institute of Oceanography, Ministry of Natural Resources of China, Xiamen 361005, China; (S.L.); (Y.L.); (S.Z.)
- School of Marine Sciences, China University of Geosciences, Beijing 100083, China
| | - Sufang Zhao
- Key Laboratory of Marine Genetic Resources, Third Institute of Oceanography, Ministry of Natural Resources of China, Xiamen 361005, China; (S.L.); (Y.L.); (S.Z.)
| | - Zongze Shao
- Key Laboratory of Marine Genetic Resources, Third Institute of Oceanography, Ministry of Natural Resources of China, Xiamen 361005, China; (S.L.); (Y.L.); (S.Z.)
- School of Environmental Science, Harbin Institute of Technology, Harbin 150090, China
- School of Marine Sciences, China University of Geosciences, Beijing 100083, China
- Southern Marine Science and Engineering Guangdong Laboratory (Zhuhai), Zhuhai 519000, China
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Jiang W, Sun J, Dong W, Zhou J, Jiang Y, Zhang W, Xin F, Jiang M. Characterization of a novel esterase and construction of a Rhodococcus-Burkholderia consortium capable of catabolism bis (2-hydroxyethyl) terephthalate. ENVIRONMENTAL RESEARCH 2023; 238:117240. [PMID: 37783328 DOI: 10.1016/j.envres.2023.117240] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/11/2023] [Revised: 09/22/2023] [Accepted: 09/25/2023] [Indexed: 10/04/2023]
Abstract
Bis (2-hydroxyethyl) terephthalate (BHET) is one of the main compounds produced by enzymatic hydrolysis or chemical depolymerization of polyethylene terephthalate (PET). However, the lack of understanding on BHET microbial metabolism is a main factor limiting the bio-upcycling of PET. In this study, BHET-degrading strains of Rhodococcus biphenylivorans GA1 and Burkholderia sp. EG1 were isolated and identified, which can grow with BHET as the sole carbon source. Furthermore, a novel esterase gene betH was cloned from strain GA1, which encodes a BHET hydrolyzing esterase with the highest activity at 30 °C and pH 7.0. In addition, the co-culture containing strain GA1 and strain EG1 could completely degrade high concentration of BHET, eliminating the inhibition on strain GA1 caused by the accumulation of intermediate metabolite ethylene glycol (EG). This work will provide potential strains and a feasible strategy for PET bio-upcycling.
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Affiliation(s)
- Wankui Jiang
- State Key Laboratory of Materials-Oriented Chemical Engineering, College of Biotechnology and Pharmaceutical Engineering, Nanjing Tech University, Nanjing, 211816, PR China
| | - Jingxiang Sun
- State Key Laboratory of Materials-Oriented Chemical Engineering, College of Biotechnology and Pharmaceutical Engineering, Nanjing Tech University, Nanjing, 211816, PR China
| | - Weiliang Dong
- State Key Laboratory of Materials-Oriented Chemical Engineering, College of Biotechnology and Pharmaceutical Engineering, Nanjing Tech University, Nanjing, 211816, PR China
| | - Jie Zhou
- State Key Laboratory of Materials-Oriented Chemical Engineering, College of Biotechnology and Pharmaceutical Engineering, Nanjing Tech University, Nanjing, 211816, PR China
| | - Yujia Jiang
- State Key Laboratory of Materials-Oriented Chemical Engineering, College of Biotechnology and Pharmaceutical Engineering, Nanjing Tech University, Nanjing, 211816, PR China
| | - Wenming Zhang
- State Key Laboratory of Materials-Oriented Chemical Engineering, College of Biotechnology and Pharmaceutical Engineering, Nanjing Tech University, Nanjing, 211816, PR China; Jiangsu National Synergetic Innovation Center for Advanced Materials (SICAM), Nanjing Tech University, Nanjing, 211816, PR China.
| | - Fengxue Xin
- State Key Laboratory of Materials-Oriented Chemical Engineering, College of Biotechnology and Pharmaceutical Engineering, Nanjing Tech University, Nanjing, 211816, PR China; Jiangsu National Synergetic Innovation Center for Advanced Materials (SICAM), Nanjing Tech University, Nanjing, 211816, PR China.
| | - Min Jiang
- State Key Laboratory of Materials-Oriented Chemical Engineering, College of Biotechnology and Pharmaceutical Engineering, Nanjing Tech University, Nanjing, 211816, PR China; Jiangsu National Synergetic Innovation Center for Advanced Materials (SICAM), Nanjing Tech University, Nanjing, 211816, PR China
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Valenzuela-Ortega M, Suitor JT, White MFM, Hinchcliffe T, Wallace S. Microbial Upcycling of Waste PET to Adipic Acid. ACS CENTRAL SCIENCE 2023; 9:2057-2063. [PMID: 38033806 PMCID: PMC10683474 DOI: 10.1021/acscentsci.3c00414] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/06/2023] [Indexed: 12/02/2023]
Abstract
Microorganisms can be genetically engineered to transform abundant waste feedstocks into value-added small molecules that would otherwise be manufactured from diminishing fossil resources. Herein, we report the first one-pot bio-upcycling of PET plastic waste into the prolific platform petrochemical and nylon precursor adipic acid in the bacterium Escherichia coli. Optimizing heterologous gene expression and enzyme activity enabled increased flux through the de novo pathway, and immobilization of whole cells in alginate hydrogels increased the stability of the rate-limiting enoate reductase BcER. The pathway enzymes were also interfaced with hydrogen gas generated by engineered E. coli DD-2 in combination with a biocompatible Pd catalyst to enable adipic acid synthesis from metabolic cis,cis-muconic acid. Together, these optimizations resulted in a one-pot conversion to adipic acid from terephthalic acid, including terephthalate samples isolated from industrial PET waste and a post-consumer plastic bottle.
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Affiliation(s)
- Marcos Valenzuela-Ortega
- Institute
of Quantitative Biology, Biochemistry and Biotechnology, School of
Biological Sciences, University of Edinburgh, Alexander Crum Brown Road, King’s
Buildings, Edinburgh, EH9
3FF, U.K.
| | - Jack T. Suitor
- Institute
of Quantitative Biology, Biochemistry and Biotechnology, School of
Biological Sciences, University of Edinburgh, Alexander Crum Brown Road, King’s
Buildings, Edinburgh, EH9
3FF, U.K.
| | - Mirren F. M. White
- Institute
of Quantitative Biology, Biochemistry and Biotechnology, School of
Biological Sciences, University of Edinburgh, Alexander Crum Brown Road, King’s
Buildings, Edinburgh, EH9
3FF, U.K.
| | - Trevor Hinchcliffe
- Impact
Solutions Ltd., Impact Technology Centre, Fraser Road, Kirkton Campus, Livingston, EH54 7BU, U.K.
| | - Stephen Wallace
- Institute
of Quantitative Biology, Biochemistry and Biotechnology, School of
Biological Sciences, University of Edinburgh, Alexander Crum Brown Road, King’s
Buildings, Edinburgh, EH9
3FF, U.K.
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40
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Connor A, Lamb JV, Delferro M, Koffas M, Zha RH. Two-step conversion of polyethylene into recombinant proteins using a microbial platform. Microb Cell Fact 2023; 22:214. [PMID: 37848881 PMCID: PMC10580613 DOI: 10.1186/s12934-023-02220-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2023] [Accepted: 09/29/2023] [Indexed: 10/19/2023] Open
Abstract
BACKGROUND The increasing prevalence of plastic waste combined with the inefficiencies of mechanical recycling has inspired interest in processes that can convert these waste streams into value-added biomaterials. To date, the microbial conversion of plastic substrates into biomaterials has been predominantly limited to polyhydroxyalkanoates production. Expanding the capabilities of these microbial conversion platforms to include a greater diversity of products generated from plastic waste streams can serve to promote the adoption of these technologies at a larger scale and encourage a more sustainable materials economy. RESULTS Herein, we report the development of a new strain of Pseudomonas bacteria capable of converting depolymerized polyethylene into high value bespoke recombinant protein products. Using hexadecane, a proxy for depolymerized polyethylene, as a sole carbon nutrient source, we optimized media compositions that facilitate robust biomass growth above 1 × 109 cfu/ml, with results suggesting the benefits of lower hydrocarbon concentrations and the use of NH4Cl as a nitrogen source. We genomically integrated recombinant genes for green fluorescent protein and spider dragline-inspired silk protein, and we showed their expression in Pseudomonas aeruginosa, reaching titers of approximately 10 mg/L when hexadecane was used as the sole carbon source. Lastly, we demonstrated that chemically depolymerized polyethylene, comprised of a mixture of branched and unbranched alkanes, could be converted into silk protein by Pseudomonas aeruginosa at titers of 11.3 ± 1.1 mg/L. CONCLUSION This work demonstrates a microbial platform for the conversion of a both alkanes and plastic-derived substrates to recombinant, protein-based materials. The findings in this work can serve as a basis for future endeavors seeking to upcycle recalcitrant plastic wastes into value-added recombinant proteins.
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Affiliation(s)
- Alexander Connor
- Department of Chemical and Biological Engineering, Rensselaer Polytechnic Institute, Troy, NY, 12180, USA
- Center for Biotechnology and Interdisciplinary Studies, Rensselaer Polytechnic Institute, Troy, NY, 12180, USA
| | - Jessica V Lamb
- Chemical Sciences and Engineering Division, Argonne National Laboratory, 9700 S Cass Ave, Lemont, IL, 60439, USA
| | - Massimiliano Delferro
- Chemical Sciences and Engineering Division, Argonne National Laboratory, 9700 S Cass Ave, Lemont, IL, 60439, USA
| | - Mattheos Koffas
- Department of Chemical and Biological Engineering, Rensselaer Polytechnic Institute, Troy, NY, 12180, USA.
- Center for Biotechnology and Interdisciplinary Studies, Rensselaer Polytechnic Institute, Troy, NY, 12180, USA.
| | - R Helen Zha
- Department of Chemical and Biological Engineering, Rensselaer Polytechnic Institute, Troy, NY, 12180, USA.
- Center for Biotechnology and Interdisciplinary Studies, Rensselaer Polytechnic Institute, Troy, NY, 12180, USA.
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41
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Qian X, Jiang M, Dong W. Tandem chemical deconstruction and biological upcycling of poly(ethylene terephthalate). Trends Biotechnol 2023; 41:1223-1226. [PMID: 37105776 DOI: 10.1016/j.tibtech.2023.03.021] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2023] [Revised: 03/22/2023] [Accepted: 03/31/2023] [Indexed: 04/29/2023]
Abstract
Upcycling processes via tandem chemical deconstruction and biological transformation has shown promise for poly(ethylene terephthalate) (PET) waste open-loop management. Under this framework, postconsumer PET becomes a low-cost and abundant starting material for the synthesis of high-value chemicals.
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Affiliation(s)
- Xiujuan Qian
- College of Biotechnology and Pharmaceutical Engineering, Nanjing Tech University, Nanjing, China; Key Laboratory for Waste Plastics Biocatalytic Degradation and Recycling, Nanjing Tech University, Nanjing, China
| | - Min Jiang
- College of Biotechnology and Pharmaceutical Engineering, Nanjing Tech University, Nanjing, China; Key Laboratory for Waste Plastics Biocatalytic Degradation and Recycling, Nanjing Tech University, Nanjing, China; State Key Laboratory of Materials-Oriented Chemical Engineering, Nanjing Tech University, Nanjing, China.
| | - Weiliang Dong
- College of Biotechnology and Pharmaceutical Engineering, Nanjing Tech University, Nanjing, China; Key Laboratory for Waste Plastics Biocatalytic Degradation and Recycling, Nanjing Tech University, Nanjing, China; State Key Laboratory of Materials-Oriented Chemical Engineering, Nanjing Tech University, Nanjing, China.
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42
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Du B, Sun M, Hui W, Xie C, Xu X. Recent Advances on Key Enzymes of Microbial Origin in the Lycopene Biosynthesis Pathway. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2023; 71:12927-12942. [PMID: 37609695 DOI: 10.1021/acs.jafc.3c03942] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 08/24/2023]
Abstract
Lycopene is a common carotenoid found mainly in ripe red fruits and vegetables that is widely used in the food industry due to its characteristic color and health benefits. Microbial synthesis of lycopene is gradually replacing the traditional methods of plant extraction and chemical synthesis as a more economical and productive manufacturing strategy. The biosynthesis of lycopene is a typical multienzyme cascade reaction, and it is important to understand the characteristics of each key enzyme involved and how they are regulated. In this paper, the catalytic characteristics of the key enzymes involved in the lycopene biosynthesis pathway and related studies are first discussed in detail. Then, the strategies applied to the key enzymes of lycopene synthesis, including fusion proteins, enzyme screening, combinatorial engineering, CRISPR/Cas9-based gene editing, DNA assembly, and scaffolding technologies are purposefully illustrated and compared in terms of both traditional and emerging multienzyme regulatory strategies. Finally, future developments and regulatory options for multienzyme synthesis of lycopene and similar secondary metabolites are also discussed.
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Affiliation(s)
- Bangmian Du
- School of Food Science and Pharmaceutical Engineering, Nanjing Normal University, Nanjing, 210046, Jiangsu Province, China
| | - Mengjuan Sun
- School of Food Science and Pharmaceutical Engineering, Nanjing Normal University, Nanjing, 210046, Jiangsu Province, China
| | - Wenyang Hui
- School of Food Science and Pharmaceutical Engineering, Nanjing Normal University, Nanjing, 210046, Jiangsu Province, China
| | - Chengjia Xie
- School of Chemical Engineering, Yangzhou Polytechnic Institute, Yangzhou 225127, Jiangsu Province, China
| | - Xian Xu
- School of Food Science and Pharmaceutical Engineering, Nanjing Normal University, Nanjing, 210046, Jiangsu Province, China
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43
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Zhang S, Xue Y, Wu Y, Zhang YX, Tan T, Niu Z. PET recycling under mild conditions via substituent-modulated intramolecular hydrolysis. Chem Sci 2023; 14:6558-6563. [PMID: 37350822 PMCID: PMC10283487 DOI: 10.1039/d3sc01161e] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2023] [Accepted: 05/24/2023] [Indexed: 06/24/2023] Open
Abstract
Catalytic depolymerization represents a promising approach for the closed-loop recycling of plastic wastes. Here, we report a knowledge-driven catalyst development for poly(ethylene terephthalate) (PET) recycling, which not only achieves more than 23-fold enhancement in specific activity but also reduces the alkali concentration by an order of magnitude compared with the conventional hydrolysis. Substituted binuclear zinc catalysts are developed to regulate biomimetic intramolecular PET hydrolysis. Hammett studies and density functional theory (DFT) calculations indicate that the substituents modify the charge densities of the active centers, and an optimal substituent should slightly increase the electron richness of the zinc sites to facilitate the formation of a six-membered ring intermediate. The understanding of the structure-activity relationship leads to an advanced catalyst with a specific activity of 778 ± 40 gPET h-1 gcatal-1 in 0.1 M NaOH, far outcompeting the conventional hydrolysis using caustic bases (<33.3 gPET h-1 gcatal-1 in 1-5 M NaOH). This work opens new avenues for environmentally benign PET recycling.
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Affiliation(s)
- Shengbo Zhang
- Department State Key Laboratory of Chemical Engineering, Department of Chemical Engineering, Tsinghua University Beijing 100084 China
| | - Yingying Xue
- Laboratory of Theoretical and Computational Nanoscience, CAS Key Laboratory of Nanophotonic Materials and Devices, National Center for Nanoscience and Technology, Chinese Academy of Sciences Beijing 100190 China
| | - Yanfen Wu
- Department State Key Laboratory of Chemical Engineering, Department of Chemical Engineering, Tsinghua University Beijing 100084 China
| | - Yu-Xiao Zhang
- Department State Key Laboratory of Chemical Engineering, Department of Chemical Engineering, Tsinghua University Beijing 100084 China
| | - Ting Tan
- Laboratory of Theoretical and Computational Nanoscience, CAS Key Laboratory of Nanophotonic Materials and Devices, National Center for Nanoscience and Technology, Chinese Academy of Sciences Beijing 100190 China
| | - Zhiqiang Niu
- Department State Key Laboratory of Chemical Engineering, Department of Chemical Engineering, Tsinghua University Beijing 100084 China
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44
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Qian X, Xin K, Zhang L, Zhou J, Xu A, Dong W, Jiang M. Integration of ARTP Mutation and Adaptive Laboratory Evolution to Reveal 1,4-Butanediol Degradation in Pseudomonas putida KT2440. Microbiol Spectr 2023; 11:e0498822. [PMID: 37067433 PMCID: PMC10269461 DOI: 10.1128/spectrum.04988-22] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2022] [Accepted: 03/30/2023] [Indexed: 04/18/2023] Open
Abstract
Biotransformation of plastics or their depolymerization monomers as raw materials would offer a better end-of-life solutions to the plastic waste dilemma. 1,4-butanediol (BDO) is one of the major depolymerization monomers of many plastics polymers. BDO valorization presents great significance for waste plastic up-recycling and fermenting feedstock exploitation. In the present study, atmospheric pressure room temperature plasma (ARTP)-induced mutation combined with adaptive laboratory evolution (ALE) was used to improve the BDO utilization capability of Pseudomonas putida KT2440. The excellent mutant P. putida NB10 was isolated and stored in the China Typical Culture Preservation Center (CCTCC) with the deposit number M 2021482. Whole-genome resequencing and transcriptome analysis revealed that the BDO degradation process consists of β-oxidation, glyoxylate carboligase (GCL) pathway, glyoxylate cycle and gluconeogenesis pathway. The imbalance between the two key intermediates (acetyl-CoA and glycolyl-CoA) and the accumulation of cytotoxic aldehydes resulted in the weak metabolism performance of KT2440 in the utilization of BDO. The balance of the carbon flux and enhanced tolerance to cytotoxic intermediates endow NB10 with great BDO degradation capability. This study deeply revealed the metabolic mechanism behind BDO degradation and provided an excellent chassis cell for BDO further up-cycling to high-value chemicals. IMPORTANCE Plastic waste represents not only a global pollution problem but also a carbon-rich, low-cost, globally renewable feedstock for industrial biotechnology. BDO is the basic material for polybutylene terephthalate (PBT), poly butylene adipate-co-terephthalate (PBAT), poly (butylene succinate) (PBS), etc. Herein, the construction of BDO valorization cell factory presents great significance for waste plastic up-recycling and novel fermentation feedstock exploitation. However, BDO is hard to be metabolized and its metabolic pathway is unclear. This study presents a P. putida mutant NB10, obtained through the integration of ARTP and ALE, displaying significant growth improvement with BDO as the sole carbon source. Further genome resequencing, transcriptome analysis and genetic engineering deeply revealed the metabolic mechanism behind BDO degradation in P. putida, this study offers an excellent microbial chassis and modification strategy for plastic waste up-cycling.
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Affiliation(s)
- Xiujuan Qian
- Key Laboratory for Waste Plastics Biocatalytic Degradation and Recycling, College of Biotechnology and Pharmaceutical Engineering, Nanjing Tech University, Nanjing, People’s Republic of China
| | - Kaiyuan Xin
- Key Laboratory for Waste Plastics Biocatalytic Degradation and Recycling, College of Biotechnology and Pharmaceutical Engineering, Nanjing Tech University, Nanjing, People’s Republic of China
| | - Lili Zhang
- Key Laboratory for Waste Plastics Biocatalytic Degradation and Recycling, College of Biotechnology and Pharmaceutical Engineering, Nanjing Tech University, Nanjing, People’s Republic of China
| | - Jie Zhou
- Key Laboratory for Waste Plastics Biocatalytic Degradation and Recycling, College of Biotechnology and Pharmaceutical Engineering, Nanjing Tech University, Nanjing, People’s Republic of China
- State Key Laboratory of Materials-Oriented Chemical Engineering, Nanjing Tech University, Nanjing, People’s Republic of China
| | - Anming Xu
- Key Laboratory for Waste Plastics Biocatalytic Degradation and Recycling, College of Biotechnology and Pharmaceutical Engineering, Nanjing Tech University, Nanjing, People’s Republic of China
| | - Weiliang Dong
- Key Laboratory for Waste Plastics Biocatalytic Degradation and Recycling, College of Biotechnology and Pharmaceutical Engineering, Nanjing Tech University, Nanjing, People’s Republic of China
- State Key Laboratory of Materials-Oriented Chemical Engineering, Nanjing Tech University, Nanjing, People’s Republic of China
| | - Min Jiang
- Key Laboratory for Waste Plastics Biocatalytic Degradation and Recycling, College of Biotechnology and Pharmaceutical Engineering, Nanjing Tech University, Nanjing, People’s Republic of China
- State Key Laboratory of Materials-Oriented Chemical Engineering, Nanjing Tech University, Nanjing, People’s Republic of China
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Wen R, Shen G, Yu Y, Xu S, Wei J, Huo Y, Jiang S. Optimization of Ti-BA efficiently for the catalytic alcoholysis of waste PET using response surface methodology. RSC Adv 2023; 13:17166-17178. [PMID: 37304773 PMCID: PMC10248717 DOI: 10.1039/d3ra01460f] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2023] [Accepted: 05/21/2023] [Indexed: 06/13/2023] Open
Abstract
A titanium benzoate (Ti-BA) catalyst was prepared by hydrothermal method, which has an ordered eight-face structure, and was used for polyethylene terephthalate (PET) depolymerization. With bis(2-hydroxyethyl)terephthalate (BHET) as the target molecule and ethylene glycol (EG) as the solvent, the best reaction conditions for catalytic alcoholysis via a PET alcoholic solution were investigated via response surface experiments and found to be a EG/PET mass ratio of 3.59, temperature of 217 °C and reaction time of 3.3 h. Under these conditions, the amount of the catalyst required was only 2% of the mass of the PET, and the yield of BHET reached 90.01% and under the same conditions, the yield of BHET could still reach 80.1%. Based on the experimental results, the mechanism of alcoholysis, Ti-BA catalyst activated ethylene glycol deprotonation to achieve the progressive degradation of polymers. This experiment provides a reference for the degradation of polymer waste and other transesterification reactions.
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Affiliation(s)
- Ruiyang Wen
- School of Petrochemical Engineering, Shenyang University of Technology Liaoyang 111003 China
| | - Guoliang Shen
- School of Petrochemical Engineering, Shenyang University of Technology Liaoyang 111003 China
| | - Yang Yu
- School of Petrochemical Engineering, Shenyang University of Technology Liaoyang 111003 China
| | - Shijie Xu
- School of Petrochemical Engineering, Shenyang University of Technology Liaoyang 111003 China
| | - Jie Wei
- School of Petrochemical Engineering, Shenyang University of Technology Liaoyang 111003 China
| | - Yue Huo
- School of Petrochemical Engineering, Shenyang University of Technology Liaoyang 111003 China
| | - Sijin Jiang
- School of Petrochemical Engineering, Shenyang University of Technology Liaoyang 111003 China
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