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Kawai F, Iizuka R, Kawabata T. Engineered polyethylene terephthalate hydrolases: perspectives and limits. Appl Microbiol Biotechnol 2024; 108:404. [PMID: 38953996 PMCID: PMC11219463 DOI: 10.1007/s00253-024-13222-2] [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: 02/09/2024] [Revised: 06/03/2024] [Accepted: 06/04/2024] [Indexed: 07/04/2024]
Abstract
Polyethylene terephthalate (PET) is a major component of plastic waste. Enzymatic PET hydrolysis is the most ecofriendly recycling technology. The biorecycling of PET waste requires the complete depolymerization of PET to terephthalate and ethylene glycol. The history of enzymatic PET depolymerization has revealed two critical issues for the industrial depolymerization of PET: industrially available PET hydrolases and pretreatment of PET waste to make it susceptible to full enzymatic hydrolysis. As none of the wild-type enzymes can satisfy the requirements for industrialization, various mutational improvements have been performed, through classical technology to state-of-the-art computational/machine-learning technology. Recent engineering studies on PET hydrolases have brought a new insight that flexibility of the substrate-binding groove may improve the efficiency of PET hydrolysis while maintaining sufficient thermostability, although the previous studies focused only on enzymatic thermostability above the glass transition temperature of PET. Industrial biorecycling of PET waste is scheduled to be implemented, using micronized amorphous PET. Next stage must be the development of PET hydrolases that can efficiently degrade crystalline parts of PET and expansion of target PET materials, not only bottles but also textiles, packages, and microplastics. This review discusses the current status of PET hydrolases, their potential applications, and their profespectal goals. KEY POINTS: • PET hydrolases must be thermophilic, but their operation must be below 70 °C • Classical and state-of-the-art engineering approaches are useful for PET hydrolases • Enzyme activity on crystalline PET is most expected for future PET biorecycling.
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Affiliation(s)
- Fusako Kawai
- Graduate School of Environmental and Life Sciences, Okayama University, 1-1-1 Tsushima-Naka, Kita-Ku, Okayama, 700-8530, Japan.
| | - Ryo Iizuka
- Graduate School of Science, The University of Tokyo, 7-3-1 Hongo, Bunkyo-Ku, Tokyo, 113-0033, Japan
| | - Takeshi Kawabata
- Graduate School of Information Sciences, Tohoku University, Aoba 6-3-09, Aoba-ku, Sendai, Miyagi, 980-8579, Japan
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2
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Boctor J, Pandey G, Xu W, Murphy DV, Hoyle FC. Nature's Plastic Predators: A Comprehensive and Bibliometric Review of Plastivore Insects. Polymers (Basel) 2024; 16:1671. [PMID: 38932021 PMCID: PMC11207432 DOI: 10.3390/polym16121671] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2024] [Revised: 05/31/2024] [Accepted: 06/07/2024] [Indexed: 06/28/2024] Open
Abstract
Unprecedented plastic production has resulted in over six billion tons of harmful waste. Certain insect taxa emerge as potential agents of plastic biodegradation. Through a comprehensive manual and bibliometric literature analysis, this review analyses and consolidates the growing literature related to insect-mediated plastic breakdown. Over 23 insect species, representing Coleoptera, Lepidoptera, and 4 other orders, have been identified for their capacity to consume plastic polymers. Natural and synthetic polymers exhibit high-level similarities in molecular structure and properties. Thus, in conjunction with comparative genomics studies, we link plastic-degrading enzymatic capabilities observed in certain insects to the exaptation of endogenous enzymes originally evolved for digesting lignin, cellulose, beeswax, keratin and chitin from their native dietary substrates. Further clarification is necessary to distinguish mineralisation from physicochemical fragmentation and to differentiate microbiome-mediated degradation from direct enzymatic reactions by insects. A bibliometric analysis of the exponentially growing body of literature showed that leading research is emerging from China and the USA. Analogies between natural and synthetic polymer's degradation pathways will inform engineering robust enzymes for practical plastic bioremediation applications. By aggregating, analysing, and interpreting published insights, this review consolidates our mechanistic understanding of insects as a potential natural solution to the escalating plastic waste crisis.
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Affiliation(s)
- Joseph Boctor
- Bioplastics Innovation Hub, Food Futures Institute, Murdoch University, Murdoch, WA 6150, Australia; (W.X.); (D.V.M.); (F.C.H.)
| | - Gunjan Pandey
- Commonwealth Scientific and Industrial Research Organisation (CSIRO), Environment, Acton, ACT 2601, Australia;
| | - Wei Xu
- Bioplastics Innovation Hub, Food Futures Institute, Murdoch University, Murdoch, WA 6150, Australia; (W.X.); (D.V.M.); (F.C.H.)
| | - Daniel V. Murphy
- Bioplastics Innovation Hub, Food Futures Institute, Murdoch University, Murdoch, WA 6150, Australia; (W.X.); (D.V.M.); (F.C.H.)
- SoilsWest, Centre for Sustainable Farming Systems, Food Futures Institute, Murdoch University, Murdoch, WA 6150, Australia
| | - Frances C. Hoyle
- Bioplastics Innovation Hub, Food Futures Institute, Murdoch University, Murdoch, WA 6150, Australia; (W.X.); (D.V.M.); (F.C.H.)
- SoilsWest, Centre for Sustainable Farming Systems, Food Futures Institute, Murdoch University, Murdoch, WA 6150, Australia
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Luo J, Yu Y, Wang K, He S, Wang L, Liang F, Chin JW, Tang S. Capturing acyl-enzyme intermediates with genetically encoded 2,3-diaminopropionic acid for hydrolase substrate identification. Nat Protoc 2024:10.1038/s41596-024-01006-x. [PMID: 38867073 DOI: 10.1038/s41596-024-01006-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2023] [Accepted: 03/29/2024] [Indexed: 06/14/2024]
Abstract
Catalytic mechanism-based, light-activated traps have recently been developed to identify the substrates of cysteine or serine hydrolases. These traps are hydrolase mutants whose catalytic cysteine or serine are replaced with genetically encoded 2,3-diaminopropionic acid (DAP). DAP-containing hydrolases specifically capture the transient thioester- or ester-linked acyl-enzyme intermediates resulting from the first step of the proteolytic reaction as their stable amide analogs. The trapped substrate fragments allow the downstream identification of hydrolase substrates by mass spectrometry and immunoblotting. In this protocol, we provide a detailed step-by-step guide for substrate capture and identification of the peptidase domain of the large tegument protein deneddylase (UL36USP) from human herpesvirus 1, both in mammalian cell lysate and live mammalian cells. Four procedures are included: Procedure 1, DAP-mediated substrate trapping in mammalian cell lysate (~8 d); Procedure 2, DAP-mediated substrate trapping in adherent mammalian cells (~6 d); Procedure 3, DAP-mediated substrate trapping in suspension mammalian cells (~5 d); and Procedure 4, substrate identification and validation (~12-13 d). Basic skills to perform protein expression in bacteria or mammalian cells, affinity enrichment and proteomic analysis are required to implement the protocol. This protocol will be a practical guide for identifying substrates of serine or cysteine hydrolases either in a complex mixture, where genetic manipulation is challenging, or in live cells such as bacteria, yeasts and mammalian cells.
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Affiliation(s)
- Juan Luo
- Department of Oncology, The First Affiliated Hospital of USTC, Key Laboratory of Immune Response and Immunotherapy, Centre for Advanced Interdisciplinary Science and Biomedicine of IHM, MOE Key Laboratory for Membraneless Organelles & Cellular Dynamics, Division of Life Sciences and Medicine, University of Science and Technology of China, Hefei, Anhui, China
| | - Yao Yu
- Department of Oncology, The First Affiliated Hospital of USTC, Key Laboratory of Immune Response and Immunotherapy, Centre for Advanced Interdisciplinary Science and Biomedicine of IHM, MOE Key Laboratory for Membraneless Organelles & Cellular Dynamics, Division of Life Sciences and Medicine, University of Science and Technology of China, Hefei, Anhui, China
| | - Ke Wang
- Department of Oncology, The First Affiliated Hospital of USTC, Key Laboratory of Immune Response and Immunotherapy, Centre for Advanced Interdisciplinary Science and Biomedicine of IHM, MOE Key Laboratory for Membraneless Organelles & Cellular Dynamics, Division of Life Sciences and Medicine, University of Science and Technology of China, Hefei, Anhui, China
| | - Sizhe He
- Department of Oncology, The First Affiliated Hospital of USTC, Key Laboratory of Immune Response and Immunotherapy, Centre for Advanced Interdisciplinary Science and Biomedicine of IHM, MOE Key Laboratory for Membraneless Organelles & Cellular Dynamics, Division of Life Sciences and Medicine, University of Science and Technology of China, Hefei, Anhui, China
| | - Longjie Wang
- Department of Oncology, The First Affiliated Hospital of USTC, Key Laboratory of Immune Response and Immunotherapy, Centre for Advanced Interdisciplinary Science and Biomedicine of IHM, MOE Key Laboratory for Membraneless Organelles & Cellular Dynamics, Division of Life Sciences and Medicine, University of Science and Technology of China, Hefei, Anhui, China
| | - Fangfang Liang
- Department of Medical Oncology, Guangxi Medical University First Affiliated Hospital, Nanning, Guangxi Zhuang Autonomous Region, China
| | - Jason W Chin
- Medical Research Council Laboratory of Molecular Biology, Cambridge, UK
| | - Shan Tang
- Department of Oncology, The First Affiliated Hospital of USTC, Key Laboratory of Immune Response and Immunotherapy, Centre for Advanced Interdisciplinary Science and Biomedicine of IHM, MOE Key Laboratory for Membraneless Organelles & Cellular Dynamics, Division of Life Sciences and Medicine, University of Science and Technology of China, Hefei, Anhui, China.
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Yang X, Su XC, Xuan W. Genetically Encoded Photocaged Proteinogenic and Non-Proteinogenic Amino Acids. Chembiochem 2024:e202400393. [PMID: 38831474 DOI: 10.1002/cbic.202400393] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2024] [Revised: 05/31/2024] [Accepted: 06/03/2024] [Indexed: 06/05/2024]
Abstract
Photocaged amino acids could be genetically encoded into proteins via genetic code expansion (GCE) and constitute unique tools for innovative protein engineering. There are a number of photocaged proteinogenic amino acids that allow strategic conversion of proteins into their photocaged variants, thus enabling spatiotemporal and non-invasive regulation of protein functions using light. Meanwhile, there are a hand of photocaged non-proteinogenic amino acids that address the challenges in directly encoding certain non-canonical amino acids (ncAAs) that structurally resemble proteinogenic ones or possess highly reactive functional groups. Herein, we would like to summarize the efforts in encoding photocaged proteinogenic and non-proteinogenic amino acids, hoping to draw more attention to this fruitful and exciting scientific campaign.
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Affiliation(s)
- Xiaochen Yang
- Frontier Science Center for Synthetic Biology (Ministry of Education), School of Life Sciences, Faculty of Medicine, Tianjin University, Tianjin, 300072, China
- State Key Laboratory and Institute of Elemento-Organic Chemistry, College of Chemistry, Nankai University, Tianjin, 300071, China
| | - Xun-Cheng Su
- State Key Laboratory and Institute of Elemento-Organic Chemistry, College of Chemistry, Nankai University, Tianjin, 300071, China
| | - Weimin Xuan
- Frontier Science Center for Synthetic Biology (Ministry of Education), School of Life Sciences, Faculty of Medicine, Tianjin University, Tianjin, 300072, China
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Oda K, Wlodawer A. Development of Enzyme-Based Approaches for Recycling PET on an Industrial Scale. Biochemistry 2024. [PMID: 38285602 DOI: 10.1021/acs.biochem.3c00554] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2024]
Abstract
Pollution by plastics such as polyethylene (PE), polypropylene (PP), polyvinyl chloride (PVC), polyurethane (PUR), polyamide (PA), polystyrene (PS), and poly(ethylene terephthalate) (PET) is now gaining worldwide attention as a critical environmental issue, closely linked to climate change. Among them, PET is particularly prone to hydrolysis, breaking down into its constituents, ethylene glycol (EG) and terephthalate (TPA). Biorecycling or bioupcycling stands out as one of the most promising methods for addressing PET pollution. For dealing with pollution by the macrosize PET, a French company Carbios has developed a pilot-scale plant for biorecycling waste PET beverage bottles into new bottles using derivatives of thermophilic leaf compost cutinase (LCC). However, this system still provides significant challenges in its practical implementation. For the micro- or nanosize PET pollution that poses significant human health risks, including cancer, no industrial-scale approach has been established so far, despite the need to develop such technologies. In this Perspective, we explore the enhancement of the low activity and thermostability of the enzyme PETase to match that of LCC, along with the potential application of microbes and enzymes for the treatment of waste PET as microplastics. Additionally, we discuss the shortcomings of the current biorecycling protocols from a life cycle assessment perspective, covering aspects such as the diversity of PET-hydrolyzing enzymes in nature, the catalytic mechanism for crystallized PET, and more. We also provide an overview of the Ideonella sakaiensis system, highlighting its ability to operate and grow at moderate temperatures, in contrast to high-temperature processes.
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Affiliation(s)
- Kohei Oda
- Department of Applied Biology, Kyoto Institute of Technology, Matsugasaki, Sakyo-ku, Kyoto 606-8585, Japan
| | - Alexander Wlodawer
- Center for Structural Biology, National Cancer Institute, Frederick, Maryland 21702, United States
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Shi L, Zhu L. Recent Advances and Challenges in Enzymatic Depolymerization and Recycling of PET Wastes. Chembiochem 2024; 25:e202300578. [PMID: 37960968 DOI: 10.1002/cbic.202300578] [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: 08/16/2023] [Revised: 11/12/2023] [Accepted: 11/13/2023] [Indexed: 11/15/2023]
Abstract
Poly (ethylene terephthalate) (PET) is one of the most commonly used plastics in daily life and various industries. Enzymatic depolymerization and recycling of post-consumer PET (pc-PET) provides a promising strategy for the sustainable circular economy of polymers. Great protein engineering efforts have been devoted to improving the depolymerization performance of PET hydrolytic enzymes (PHEs). In this review, we first discuss the mechanisms and challenges of enzymatic PET depolymerization. Subsequently, we summarize the state-of-the-art engineering of PHEs including rational design, machine learning, and directed evolution for improved depolymerization performance, and highlight the advances in screening methods of PHEs. We further discuss several factors that affect the enzymatic depolymerization efficiency. We conclude with our perspective on the opportunities and challenges in bio-recycling and bio-upcycling of PET wastes.
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Affiliation(s)
- Lixia Shi
- Key Laboratory of Engineering Biology for Low-Carbon Manufacturing, Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, 32 West 7th Avenue, Tianjin Airport Economic Area, Tianjin, 300308, China
- National Technology Innovation Center of Synthetic Biology, 32 West 7th Avenue, Tianjin Airport Economic Area, Tianjin, 300308, China
| | - Leilei Zhu
- Key Laboratory of Engineering Biology for Low-Carbon Manufacturing, Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, 32 West 7th Avenue, Tianjin Airport Economic Area, Tianjin, 300308, China
- National Technology Innovation Center of Synthetic Biology, 32 West 7th Avenue, Tianjin Airport Economic Area, Tianjin, 300308, China
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7
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Zhou H, Shi S, You Q, Zhang K, Chen Y, Zheng D, Sun J. Polyethylene Terephthalate Hydrolases in Human Gut Microbiota and Their Implications for Human Health. Microorganisms 2024; 12:138. [PMID: 38257965 PMCID: PMC10820491 DOI: 10.3390/microorganisms12010138] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2023] [Revised: 01/05/2024] [Accepted: 01/06/2024] [Indexed: 01/24/2024] Open
Abstract
Polyethylene terephthalate (PET), primarily utilized for food and beverage packaging, consistently finds its way into the human gut, thereby exerting adverse effects on human health. PET hydrolases, critical for the degradation of PET, have been predominantly sourced from environmental microbial communities. Given the fact that the human gut harbors a vast and intricate consortium of microorganisms, inquiry into the presence of potential PET hydrolases within the human gut microbiota becomes imperative. In this investigation, we meticulously screened 22,156 homologous sequences that could potentially encode PET hydrolases using the hidden Markov model (HMM) paradigm, drawing from 4984 cultivated genomes of healthy human gut bacteria. Subsequently, we methodically validated the hydrolytic efficacy of five selected candidate PET hydrolases on both PET films and powders composed of micro-plastics (MPs). Notably, our study also unveiled the influence of both diverse PET MP powders and their resultant hydrolysates on the modulation of cytokine expression in macrophages. In summary, our research underscores the ubiquitous prevalence and considerable potential of the human gut microbiota in PET hydrolysis. Furthermore, our study significantly contributes to the holistic evaluation of the potential health hazards posed by PET MPs to human well-being.
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Affiliation(s)
- Heqi Zhou
- State Key Laboratory of Organ Failure Research, Key Laboratory of Infectious Diseases Research in South China, Ministry of Education, Guangdong Provincial Key Laboratory of Viral Hepatitis Research, Guangdong Provincial Clinical Research Center for Viral Hepatitis, Department of Infectious Diseases, Nanfang Hospital, Southern Medical University, Guangzhou 510515, China; (H.Z.); (Q.Y.); (K.Z.); (Y.C.); (D.Z.)
| | - Songbiao Shi
- South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou 510301, China;
| | - Qiuhong You
- State Key Laboratory of Organ Failure Research, Key Laboratory of Infectious Diseases Research in South China, Ministry of Education, Guangdong Provincial Key Laboratory of Viral Hepatitis Research, Guangdong Provincial Clinical Research Center for Viral Hepatitis, Department of Infectious Diseases, Nanfang Hospital, Southern Medical University, Guangzhou 510515, China; (H.Z.); (Q.Y.); (K.Z.); (Y.C.); (D.Z.)
| | - Kaikai Zhang
- State Key Laboratory of Organ Failure Research, Key Laboratory of Infectious Diseases Research in South China, Ministry of Education, Guangdong Provincial Key Laboratory of Viral Hepatitis Research, Guangdong Provincial Clinical Research Center for Viral Hepatitis, Department of Infectious Diseases, Nanfang Hospital, Southern Medical University, Guangzhou 510515, China; (H.Z.); (Q.Y.); (K.Z.); (Y.C.); (D.Z.)
| | - Yuchuan Chen
- State Key Laboratory of Organ Failure Research, Key Laboratory of Infectious Diseases Research in South China, Ministry of Education, Guangdong Provincial Key Laboratory of Viral Hepatitis Research, Guangdong Provincial Clinical Research Center for Viral Hepatitis, Department of Infectious Diseases, Nanfang Hospital, Southern Medical University, Guangzhou 510515, China; (H.Z.); (Q.Y.); (K.Z.); (Y.C.); (D.Z.)
| | - Dekai Zheng
- State Key Laboratory of Organ Failure Research, Key Laboratory of Infectious Diseases Research in South China, Ministry of Education, Guangdong Provincial Key Laboratory of Viral Hepatitis Research, Guangdong Provincial Clinical Research Center for Viral Hepatitis, Department of Infectious Diseases, Nanfang Hospital, Southern Medical University, Guangzhou 510515, China; (H.Z.); (Q.Y.); (K.Z.); (Y.C.); (D.Z.)
| | - Jian Sun
- State Key Laboratory of Organ Failure Research, Key Laboratory of Infectious Diseases Research in South China, Ministry of Education, Guangdong Provincial Key Laboratory of Viral Hepatitis Research, Guangdong Provincial Clinical Research Center for Viral Hepatitis, Department of Infectious Diseases, Nanfang Hospital, Southern Medical University, Guangzhou 510515, China; (H.Z.); (Q.Y.); (K.Z.); (Y.C.); (D.Z.)
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Qi X, Ji M, Yin CF, Zhou NY, Liu Y. Glacier as a source of novel polyethylene terephthalate hydrolases. Environ Microbiol 2023; 25:2822-2833. [PMID: 37775503 DOI: 10.1111/1462-2920.16516] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2023] [Accepted: 09/20/2023] [Indexed: 10/01/2023]
Abstract
Polyethylene terephthalate (PET) is a major component of microplastic contamination globally, which is now detected in pristine environments including Polar and mountain glaciers. As a carbon-rich molecule, PET could be a carbon source for microorganisms dwelling in glacier habitats. Thus, glacial microorganisms may be potential PET degraders with novel PET hydrolases. Here, we obtained 414 putative PET hydrolase sequences by searching a global glacier metagenome dataset. Metagenomes from the Alps and Tibetan glaciers exhibited a higher relative abundance of putative PET hydrolases than those from the Arctic and Antarctic. Twelve putative PET hydrolase sequences were cloned and expressed, with one sequence (designated as GlacPETase) proven to degrade amorphous PET film with a similar performance as IsPETase, but with a higher thermostability. GlacPETase exhibited only 30% sequence identity to known active PET hydrolases with a novel disulphide bridge location and, therefore may represent a novel PET hydrolases class. The present work suggests that extreme carbon-poor environments may harbour a diverse range of known and novel PET hydrolases for carbon acquisition as an environmental adaptation mechanism.
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Affiliation(s)
- Xiaoyan Qi
- State Key Laboratory of Microbial Metabolism, Joint International Research Laboratory of Metabolic and Developmental Sciences, and School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai, China
| | - Mukan Ji
- Center for Pan-third Pole Environment, Lanzhou University, Lanzhou, China
| | - Chao-Fan Yin
- State Key Laboratory of Microbial Metabolism, Joint International Research Laboratory of Metabolic and Developmental Sciences, and School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai, China
| | - Ning-Yi Zhou
- State Key Laboratory of Microbial Metabolism, Joint International Research Laboratory of Metabolic and Developmental Sciences, and School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai, China
| | - Yongqin Liu
- Center for Pan-third Pole Environment, Lanzhou University, Lanzhou, China
- State Key Laboratory of Tibetan Plateau Earth System, Resources and Environment (TPESRE), Institute of Tibetan Plateau Research, Chinese Academy of Sciences, Beijing, China
- University of Chinese Academy of Sciences, Beijing, China
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Sui B, Wang T, Fang J, Hou Z, Shu T, Lu Z, Liu F, Zhu Y. Recent advances in the biodegradation of polyethylene terephthalate with cutinase-like enzymes. Front Microbiol 2023; 14:1265139. [PMID: 37849919 PMCID: PMC10577388 DOI: 10.3389/fmicb.2023.1265139] [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: 07/22/2023] [Accepted: 09/15/2023] [Indexed: 10/19/2023] Open
Abstract
Polyethylene terephthalate (PET) is a synthetic polymer in the polyester family. It is widely found in objects used daily, including packaging materials (such as bottles and containers), textiles (such as fibers), and even in the automotive and electronics industries. PET is known for its excellent mechanical properties, chemical resistance, and transparency. However, these features (e.g., high hydrophobicity and high molecular weight) also make PET highly resistant to degradation by wild-type microorganisms or physicochemical methods in nature, contributing to the accumulation of plastic waste in the environment. Therefore, accelerated PET recycling is becoming increasingly urgent to address the global environmental problem caused by plastic wastes and prevent plastic pollution. In addition to traditional physical cycling (e.g., pyrolysis, gasification) and chemical cycling (e.g., chemical depolymerization), biodegradation can be used, which involves breaking down organic materials into simpler compounds by microorganisms or PET-degrading enzymes. Lipases and cutinases are the two classes of enzymes that have been studied extensively for this purpose. Biodegradation of PET is an attractive approach for managing PET waste, as it can help reduce environmental pollution and promote a circular economy. During the past few years, great advances have been accomplished in PET biodegradation. In this review, current knowledge on cutinase-like PET hydrolases (such as TfCut2, Cut190, HiC, and LCC) was described in detail, including the structures, ligand-protein interactions, and rational protein engineering for improved PET-degrading performance. In particular, applications of the engineered catalysts were highlighted, such as improving the PET hydrolytic activity by constructing fusion proteins. The review is expected to provide novel insights for the biodegradation of complex polymers.
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Affiliation(s)
- Beibei Sui
- School of Biological Science, Jining Medical University, Jining, Shandong, China
| | - Tao Wang
- School of Biological Science, Jining Medical University, Jining, Shandong, China
| | - Jingxiang Fang
- Rizhao Administration for Market Regulation, Rizhao, Shandong, China
| | - Zuoxuan Hou
- School of Biological Science, Jining Medical University, Jining, Shandong, China
| | - Ting Shu
- School of Biological Science, Jining Medical University, Jining, Shandong, China
| | - Zhenhua Lu
- College of Chemical and Biological Engineering, Zhejiang University, Hangzhou, Zhejiang, China
| | - Fei Liu
- School of Biological Science, Jining Medical University, Jining, Shandong, China
| | - Youshuang Zhu
- School of Biological Science, Jining Medical University, Jining, Shandong, China
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Xu W, Cai X, Wu Y, Wen Y, Su R, Zhang Y, Huang Y, Zheng Q, Hu L, Cui X, Zheng L, Zhang S, Gu W, Song W, Guo S, Zhu C. Biomimetic single Al-OH site with high acetylcholinesterase-like activity and self-defense ability for neuroprotection. Nat Commun 2023; 14:6064. [PMID: 37770453 PMCID: PMC10539540 DOI: 10.1038/s41467-023-41765-x] [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: 04/14/2023] [Accepted: 09/19/2023] [Indexed: 09/30/2023] Open
Abstract
Neurotoxicity of organophosphate compounds (OPs) can catastrophically cause nervous system injury by inhibiting acetylcholinesterase (AChE) expression. Although artificial systems have been developed for indirect neuroprotection, they are limited to dissociating P-O bonds for eliminating OPs. However, these systems have failed to overcome the deactivation of AChE. Herein, we report our finding that Al3+ is engineered onto the nodes of metal-organic framework to synthesize MOF-808-Al with enhanced Lewis acidity. The resultant MOF-808-Al efficiently mimics the catalytic behavior of AChE and has a self-defense ability to break the activity inhibition by OPs. Mechanism investigations elucidate that Al3+ Lewis acid sites with a strong polarization effect unite the highly electronegative -OH groups to form the enzyme-like catalytic center, resulting in superior substrate activation and nucleophilic attack ability with a 2.7-fold activity improvement. The multifunctional MOF-808-Al, which has satisfactory biosafety, is efficient in reducing neurotoxic effects and preventing neuronal tissue damage.
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Affiliation(s)
- Weiqing Xu
- National Key Laboratory of Green Pesticide, International Joint Research Center for Intelligent Biosensing Technology and Health, College of Chemistry, Central China Normal University, Wuhan, 430079, P.R. China
| | - Xiaoli Cai
- Department of Nutrition, Hygiene and Toxicology, School of Public Health, Medical College, Wuhan University of Science and Technology, Wuhan, 430065, P.R. China
| | - Yu Wu
- National Key Laboratory of Green Pesticide, International Joint Research Center for Intelligent Biosensing Technology and Health, College of Chemistry, Central China Normal University, Wuhan, 430079, P.R. China
| | - Yating Wen
- National Key Laboratory of Green Pesticide, International Joint Research Center for Intelligent Biosensing Technology and Health, College of Chemistry, Central China Normal University, Wuhan, 430079, P.R. China
| | - Rina Su
- National Key Laboratory of Green Pesticide, International Joint Research Center for Intelligent Biosensing Technology and Health, College of Chemistry, Central China Normal University, Wuhan, 430079, P.R. China
| | - Yu Zhang
- National Key Laboratory of Green Pesticide, International Joint Research Center for Intelligent Biosensing Technology and Health, College of Chemistry, Central China Normal University, Wuhan, 430079, P.R. China
| | - Yuteng Huang
- Department of Nutrition, Hygiene and Toxicology, School of Public Health, Medical College, Wuhan University of Science and Technology, Wuhan, 430065, P.R. China
| | - Qihui Zheng
- Department of Nutrition, Hygiene and Toxicology, School of Public Health, Medical College, Wuhan University of Science and Technology, Wuhan, 430065, P.R. China
| | - Liuyong Hu
- School of Materials Science and Engineering, Wuhan Institute of Technology, Wuhan, 430205, P.R. China
| | - Xiaowen Cui
- Beijing Synchrotron Radiation Facility, Institute of High Energy Physics Department, Chinese Academy of Sciences Institution, Beijing, 100049, P.R. China
| | - Lirong Zheng
- Beijing Synchrotron Radiation Facility, Institute of High Energy Physics Department, Chinese Academy of Sciences Institution, Beijing, 100049, P.R. China
| | - Shipeng Zhang
- School of Materials Science and Engineering, Peking University, Beijing, 100871, P.R. China
| | - Wenling Gu
- National Key Laboratory of Green Pesticide, International Joint Research Center for Intelligent Biosensing Technology and Health, College of Chemistry, Central China Normal University, Wuhan, 430079, P.R. China
| | - Weiyu Song
- State Key Laboratory of Heavy Oil Processing, College of New Energy and Materials, China University of Petroleum, Beijing, 102249, P.R. China
| | - Shaojun Guo
- School of Materials Science and Engineering, Peking University, Beijing, 100871, P.R. China.
| | - Chengzhou Zhu
- National Key Laboratory of Green Pesticide, International Joint Research Center for Intelligent Biosensing Technology and Health, College of Chemistry, Central China Normal University, Wuhan, 430079, P.R. China.
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Alletto P, Garcia AM, Marchesan S. Short Peptides for Hydrolase Supramolecular Mimicry and Their Potential Applications. Gels 2023; 9:678. [PMID: 37754360 PMCID: PMC10529927 DOI: 10.3390/gels9090678] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2023] [Revised: 08/19/2023] [Accepted: 08/21/2023] [Indexed: 09/28/2023] Open
Abstract
Hydrolases are enzymes that have found numerous applications in various industrial sectors spanning from pharmaceuticals to foodstuff and beverages, consumers' products such as detergents and personal care, textiles, and even for biodiesel production and environmental bioremediation. Self-assembling and gelling short peptides have been designed for their mimicry so that their supramolecular organization leads to the creation of hydrophobic pockets for catalysis to occur. Catalytic gels of this kind can also find numerous industrial applications to address important global challenges of our time. This concise review focuses on the last 5 years of progress in this fast-paced, popular field of research with an eye towards the future.
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Affiliation(s)
- Paola Alletto
- Chemical and Pharmaceutical Sciences Department, University of Trieste, 34127 Trieste, Italy
- Instituto Regional de Investigación Científica Aplicada (IRICA), Universidad de Castilla-La Mancha, 13071 Ciudad Real, Spain
- Facultad de Ciencias y Tecnologías Químicas, Universidad de Castilla-La Mancha, 13071 Ciudad Real, Spain
| | - Ana Maria Garcia
- Instituto Regional de Investigación Científica Aplicada (IRICA), Universidad de Castilla-La Mancha, 13071 Ciudad Real, Spain
- Facultad de Ciencias y Tecnologías Químicas, Universidad de Castilla-La Mancha, 13071 Ciudad Real, Spain
| | - Silvia Marchesan
- Chemical and Pharmaceutical Sciences Department, University of Trieste, 34127 Trieste, Italy
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12
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Williams GB, Ma H, Khusnutdinova AN, Yakunin AF, Golyshin PN. Harnessing extremophilic carboxylesterases for applications in polyester depolymerisation and plastic waste recycling. Essays Biochem 2023; 67:715-729. [PMID: 37334661 PMCID: PMC10423841 DOI: 10.1042/ebc20220255] [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: 03/19/2023] [Revised: 06/01/2023] [Accepted: 06/05/2023] [Indexed: 06/20/2023]
Abstract
The steady growth in industrial production of synthetic plastics and their limited recycling have resulted in severe environmental pollution and contribute to global warming and oil depletion. Currently, there is an urgent need to develop efficient plastic recycling technologies to prevent further environmental pollution and recover chemical feedstocks for polymer re-synthesis and upcycling in a circular economy. Enzymatic depolymerization of synthetic polyesters by microbial carboxylesterases provides an attractive addition to existing mechanical and chemical recycling technologies due to enzyme specificity, low energy consumption, and mild reaction conditions. Carboxylesterases constitute a diverse group of serine-dependent hydrolases catalysing the cleavage and formation of ester bonds. However, the stability and hydrolytic activity of identified natural esterases towards synthetic polyesters are usually insufficient for applications in industrial polyester recycling. This necessitates further efforts on the discovery of robust enzymes, as well as protein engineering of natural enzymes for enhanced activity and stability. In this essay, we discuss the current knowledge of microbial carboxylesterases that degrade polyesters (polyesterases) with focus on polyethylene terephthalate (PET), which is one of the five major synthetic polymers. Then, we briefly review the recent progress in the discovery and protein engineering of microbial polyesterases, as well as developing enzyme cocktails and secreted protein expression for applications in the depolymerisation of polyester blends and mixed plastics. Future research aimed at the discovery of novel polyesterases from extreme environments and protein engineering for improved performance will aid developing efficient polyester recycling technologies for the circular plastics economy.
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Affiliation(s)
- Gwion B Williams
- Centre for Environmental Biotechnology, School of Natural Sciences, Bangor University, Deiniol Road, Bangor LL57 2UW, U.K
| | - Hairong Ma
- Centre for Environmental Biotechnology, School of Natural Sciences, Bangor University, Deiniol Road, Bangor LL57 2UW, U.K
| | - Anna N Khusnutdinova
- Centre for Environmental Biotechnology, School of Natural Sciences, Bangor University, Deiniol Road, Bangor LL57 2UW, U.K
| | - Alexander F Yakunin
- Centre for Environmental Biotechnology, School of Natural Sciences, Bangor University, Deiniol Road, Bangor LL57 2UW, U.K
| | - Peter N Golyshin
- Centre for Environmental Biotechnology, School of Natural Sciences, Bangor University, Deiniol Road, Bangor LL57 2UW, U.K
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13
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Galarza–Verkovitch D, Turak O, Wiese J, Rahn T, Hentschel U, Borchert E. Bioprospecting for polyesterase activity relevant for PET degradation in marine Enterobacterales isolates. AIMS Microbiol 2023; 9:518-539. [PMID: 37649797 PMCID: PMC10462454 DOI: 10.3934/microbiol.2023027] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2023] [Revised: 05/24/2023] [Accepted: 06/07/2023] [Indexed: 09/01/2023] Open
Abstract
Plastics have quickly become an integral part of modern life. Due to excessive production and improper waste disposal, they are recognized as contaminants present in practically all habitat types. Although there are several polymers, polyethylene terephthalate (PET) is of particular concern due to its abundance in the environment. There is a need for a solution that is both cost-effective and ecologically friendly to address this pollutant. The use of microbial depolymerizing enzymes could offer a biological avenue for plastic degradation, though the full potential of these enzymes is yet to be uncovered. The purpose of this study was to use (1) plate-based screening methods to investigate the plastic degradation potential of marine bacteria from the order Enterobacterales collected from various organismal and environmental sources, and (2) perform genome-based analysis to identify polyesterases potentially related to PET degradation. 126 bacterial isolates were obtained from the strain collection of RD3, Research Unit Marine Symbioses-GEOMAR-and sequentially tested for esterase and polyesterase activity, in combination here referred to as PETase-like activity. The results show that members of the microbial families Alteromonadaceae, Shewanellaceae, and Vibrionaceae, derived from marine sponges and bryozoans, are the most promising candidates within the order Enterobacterales. Furthermore, 389 putative hydrolases from the α/β superfamily were identified in 23 analyzed genomes, of which 22 were sequenced for this study. Several candidates showed similarities with known PETases, indicating underlying enzymatic potential within the order Enterobacterales for PET degradation.
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Affiliation(s)
| | - Onur Turak
- GEOMAR Helmholtz Centre for Ocean Research Kiel, Kiel, Schleswig-Holstein, Germany
| | - Jutta Wiese
- GEOMAR Helmholtz Centre for Ocean Research Kiel, Kiel, Schleswig-Holstein, Germany
| | - Tanja Rahn
- GEOMAR Helmholtz Centre for Ocean Research Kiel, Kiel, Schleswig-Holstein, Germany
| | - Ute Hentschel
- GEOMAR Helmholtz Centre for Ocean Research Kiel, Kiel, Schleswig-Holstein, Germany
- Christian-Albrechts University of Kiel, Kiel, Schleswig-Holstein, Germany
| | - Erik Borchert
- GEOMAR Helmholtz Centre for Ocean Research Kiel, Kiel, Schleswig-Holstein, Germany
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14
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White MFM, Wallace S. A New PETase from the Human Saliva Metagenome and Its Functional Modification via Genetic Code Expansion in Bacteria. ANGEWANDTE CHEMIE (WEINHEIM AN DER BERGSTRASSE, GERMANY) 2023; 135:e202216963. [PMID: 38516330 PMCID: PMC10952614 DOI: 10.1002/ange.202216963] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/17/2022] [Indexed: 01/03/2023]
Abstract
The discovery and engineering of new plastic degrading enzymes is an important challenge in chemical biotechnology to enable transition to a more sustainable and circular plastics economy. This field has so far yielded a range of enzymes and microbial pathways for the recycling and valorization of plastic waste. New research from Uttamapinant et al. reports the discovery of a novel polyethylene terephthalate (PET) hydrolase from the human saliva metagenome that displays improved properties and catalytic performance over previously characterized PET hydrolases (PETases). The authors also demonstrate the site-specific incorporation of a photocaged unnatural amino acid, 2,3-diaminopropionic acid (DAP), which upon photodecaging enables covalent binding of DAP to the PET surface. Thus, this work highlights metagenomic datasets as an untapped source of new PET degrading enzymes and the chemical modification of PETases via genetic code expansion, enabling new biotechnologies for the circular plastics economy.
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Affiliation(s)
- Mirren F. M. White
- Institute of Quantitative BiologyBiochemistry and BiotechnologySchool of Biological SciencesUniversity of Edinburgh, King's BuildingsAlexander Crum Brown RoadEdinburghEH9 3FFUK
| | - Stephen Wallace
- Institute of Quantitative BiologyBiochemistry and BiotechnologySchool of Biological SciencesUniversity of Edinburgh, King's BuildingsAlexander Crum Brown RoadEdinburghEH9 3FFUK
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15
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White MFM, Wallace S. A New PETase from the Human Saliva Metagenome and Its Functional Modification via Genetic Code Expansion in Bacteria. Angew Chem Int Ed Engl 2023; 62:e202216963. [PMID: 36592375 PMCID: PMC10947391 DOI: 10.1002/anie.202216963] [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: 11/17/2022] [Revised: 12/20/2022] [Accepted: 12/28/2022] [Indexed: 01/03/2023]
Abstract
The discovery and engineering of new plastic degrading enzymes is an important challenge in chemical biotechnology to enable transition to a more sustainable and circular plastics economy. This field has so far yielded a range of enzymes and microbial pathways for the recycling and valorization of plastic waste. New research from Uttamapinant et al. reports the discovery of a novel polyethylene terephthalate (PET) hydrolase from the human saliva metagenome that displays improved properties and catalytic performance over previously characterized PET hydrolases (PETases). The authors also demonstrate the site-specific incorporation of a photocaged unnatural amino acid, 2,3-diaminopropionic acid (DAP), which upon photodecaging enables covalent binding of DAP to the PET surface. Thus, this work highlights metagenomic datasets as an untapped source of new PET degrading enzymes and the chemical modification of PETases via genetic code expansion, enabling new biotechnologies for the circular plastics economy.
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Affiliation(s)
- Mirren F. M. White
- Institute of Quantitative BiologyBiochemistry and BiotechnologySchool of Biological SciencesUniversity of Edinburgh, King's BuildingsAlexander Crum Brown RoadEdinburghEH9 3FFUK
| | - Stephen Wallace
- Institute of Quantitative BiologyBiochemistry and BiotechnologySchool of Biological SciencesUniversity of Edinburgh, King's BuildingsAlexander Crum Brown RoadEdinburghEH9 3FFUK
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16
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Weigert S, Perez‐Garcia P, Gisdon FJ, Gagsteiger A, Schweinshaut K, Ullmann GM, Chow J, Streit WR, Höcker B. Investigation of the halophilic PET hydrolase PET6 from Vibrio gazogenes. Protein Sci 2022; 31:e4500. [PMID: 36336469 PMCID: PMC9679969 DOI: 10.1002/pro.4500] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2022] [Revised: 10/21/2022] [Accepted: 11/03/2022] [Indexed: 11/09/2022]
Abstract
The handling of plastic waste and the associated ubiquitous occurrence of microplastic poses one of the biggest challenges of our time. Recent investigations of plastic degrading enzymes have opened new prospects for biological microplastic decomposition as well as recycling applications. For polyethylene terephthalate, in particular, several natural and engineered enzymes are known to have such promising properties. From a previous study that identified new PETase candidates by homology search, we chose the candidate PET6 from the globally distributed, halophilic organism Vibrio gazogenes for further investigation. By mapping the occurrence of Vibrios containing PET6 homologs we demonstrated their ubiquitous prevalence in the pangenome of several Vibrio strains. The biochemical characterization of PET6 showed that PET6 has a comparatively lower activity than other enzymes but also revealed a superior turnover at very high salt concentrations. The crystal structure of PET6 provides structural insights into this adaptation to saline environments. By grafting only a few beneficial mutations from other PET degrading enzymes onto PET6, we increased the activity up to three-fold, demonstrating the evolutionary potential of the enzyme. MD simulations of the variant helped rationalize the mutational effects of those mutants and elucidate the interaction of the enzyme with a PET substrate. With tremendous amounts of plastic waste in the Ocean and the prevalence of Vibrio gazogenes in marine biofilms and estuarine marshes, our findings suggest that Vibrio and the PET6 enzyme are worthy subjects to study the PET degradation in marine environments.
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Affiliation(s)
| | - Pablo Perez‐Garcia
- Department of Microbiology and BiotechnologyUniversity of HamburgHamburgGermany
| | | | | | | | | | - Jennifer Chow
- Department of Microbiology and BiotechnologyUniversity of HamburgHamburgGermany
| | - Wolfgang R. Streit
- Department of Microbiology and BiotechnologyUniversity of HamburgHamburgGermany
| | - Birte Höcker
- Department of BiochemistryUniversity of BayreuthBayreuthGermany
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17
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Kawai F, Furushima Y, Mochizuki N, Muraki N, Yamashita M, Iida A, Mamoto R, Tosha T, Iizuka R, Kitajima S. Efficient depolymerization of polyethylene terephthalate (PET) and polyethylene furanoate by engineered PET hydrolase Cut190. AMB Express 2022; 12:134. [DOI: 10.1186/s13568-022-01474-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2022] [Accepted: 10/05/2022] [Indexed: 11/10/2022] Open
Abstract
AbstractThe enzymatic recycling of polyethylene terephthalate (PET) can be a promising approach to tackle the problem of plastic waste. The thermostability and activity of PET-hydrolyzing enzymes are still insufficient for practical application. Pretreatment of PET waste is needed for bio-recycling. Here, we analyzed the degradation of PET films, packages, and bottles using the newly engineered cutinase Cut190. Using gel permeation chromatography and high-performance liquid chromatography, the degradation of PET films by the Cut190 variant was shown to proceed via a repeating two-step hydrolysis process; initial endo-type scission of a surface polymer chain, followed by exo-type hydrolysis to produce mono/bis(2-hydroxyethyl) terephthalate and terephthalate from the ends of fragmented polymer molecules. Amorphous PET powders were degraded more than twofold higher than amorphous PET film with the same weight. Moreover, homogenization of post-consumer PET products, such as packages and bottles, increased their degradability, indicating the importance of surface area for the enzymatic hydrolysis of PET. In addition, it was required to maintain an alkaline pH to enable continuous enzymatic hydrolysis, by increasing the buffer concentration (HEPES, pH 9.0) depending on the level of the acidic products formed. The cationic surfactant dodecyltrimethylammonium chloride promoted PET degradation via adsorption on the PET surface and binding to the anionic surface of the Cut190 variant. The Cut190 variant also hydrolyzed polyethylene furanoate. Using the best performing Cut190 variant (L136F/Q138A/S226P/R228S/D250C-E296C/Q123H/N202H/K305del/L306del/N307del) and amorphous PET powders, more than 90 mM degradation products were obtained in 3 days and approximately 80 mM in 1 day.
Graphical Abstract
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