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Zheng L, Wang M, Li Y, Xiong Y, Wu C. Recycling and Degradation of Polyamides. Molecules 2024; 29:1742. [PMID: 38675560 PMCID: PMC11052090 DOI: 10.3390/molecules29081742] [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: 03/08/2024] [Revised: 03/31/2024] [Accepted: 04/10/2024] [Indexed: 04/28/2024] Open
Abstract
As one of the five major engineering plastics, polyamide brings many benefits to humans in the fields of transportation, clothing, entertainment, health, and more. However, as the production of polyamide increases year by year, the pollution problems it causes are becoming increasingly severe. This article reviews the current recycling and treatment processes of polyamide, such as chemical, mechanical, and energy recovery, and degradation methods such as thermal oxidation, photooxidation, enzyme degradation, etc. Starting from the synthesis mechanism of polyamide, it discusses the advantages and disadvantages of different treatment methods of polyamide to obtain more environmentally friendly and economical treatment schemes. Finding enzymes that can degrade high-molecular-weight polyamides, exploring the recovery of polyamides under mild conditions, synthesizing environmentally degradable polyamides through copolymerization or molecular design, and finally preparing degradable bio-based polyamides may be the destination of polyamide.
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Affiliation(s)
- Lin Zheng
- Hubei Provincial Key Laboratory of Green Materials for Light Industry, Collaborative Innovation Center of Green Light-Weight Materials and Processing, New Materials and Green Manufacturing Talent Introduction and Innovation Demonstration Base, School of Materials and Chemical Engineering, Hubei University of Technology, Wuhan 430068, China; (L.Z.); (M.W.); (Y.L.); (Y.X.)
| | - Mengjin Wang
- Hubei Provincial Key Laboratory of Green Materials for Light Industry, Collaborative Innovation Center of Green Light-Weight Materials and Processing, New Materials and Green Manufacturing Talent Introduction and Innovation Demonstration Base, School of Materials and Chemical Engineering, Hubei University of Technology, Wuhan 430068, China; (L.Z.); (M.W.); (Y.L.); (Y.X.)
| | - Yaoqin Li
- Hubei Provincial Key Laboratory of Green Materials for Light Industry, Collaborative Innovation Center of Green Light-Weight Materials and Processing, New Materials and Green Manufacturing Talent Introduction and Innovation Demonstration Base, School of Materials and Chemical Engineering, Hubei University of Technology, Wuhan 430068, China; (L.Z.); (M.W.); (Y.L.); (Y.X.)
| | - Yan Xiong
- Hubei Provincial Key Laboratory of Green Materials for Light Industry, Collaborative Innovation Center of Green Light-Weight Materials and Processing, New Materials and Green Manufacturing Talent Introduction and Innovation Demonstration Base, School of Materials and Chemical Engineering, Hubei University of Technology, Wuhan 430068, China; (L.Z.); (M.W.); (Y.L.); (Y.X.)
- Hubei Longzhong Laboratory, Xiangyang 441000, China
| | - Chonggang Wu
- Hubei Provincial Key Laboratory of Green Materials for Light Industry, Collaborative Innovation Center of Green Light-Weight Materials and Processing, New Materials and Green Manufacturing Talent Introduction and Innovation Demonstration Base, School of Materials and Chemical Engineering, Hubei University of Technology, Wuhan 430068, China; (L.Z.); (M.W.); (Y.L.); (Y.X.)
- Hubei Longzhong Laboratory, Xiangyang 441000, China
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Li A, Cui H, Sheng Y, Qiao J, Li X, Huang H. Global plastic upcycling during and after the COVID-19 pandemic: The status and perspective. JOURNAL OF ENVIRONMENTAL CHEMICAL ENGINEERING 2023; 11:110092. [PMID: 37200549 PMCID: PMC10167783 DOI: 10.1016/j.jece.2023.110092] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 02/07/2023] [Revised: 04/10/2023] [Accepted: 05/08/2023] [Indexed: 05/20/2023]
Abstract
Plastic pollution has become one of the most pressing environmental issues worldwide since the vast majority of post-consumer plastics are hard to degrade in the environment. The coronavirus disease (COVID-19) pandemic had disrupted the previous effort of plastic pollution mitigation to a great extent due to the overflow of plastic-based medical waste. In the post-pandemic era, the remaining challenge is how to motivate global action towards a plastic circular economy. The need for one package of sustainable and systematic plastic upcycling approaches has never been greater to address such a challenge. In this review, we summarized the threat of plastic pollution during COVID-19 to public health and ecosystem. In order to solve the aforementioned challenges, we present a shifting concept, regeneration value from plastic waste, that provides four promising pathways to achieve a sustainable circular economy: 1) Increasing reusability and biodegradability of plastics; 2) Transforming plastic waste into high-value products by chemical approaches; 3) The closed-loop recycling can be promoted by biodegradation; 4) Involving renewable energy into plastic upcycling. Additionally, the joint efforts from different social perspectives are also encouraged to create the necessary economic and environmental impetus for a circular economy.
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Affiliation(s)
- Anni Li
- School of Food Science and Pharmaceutical Engineering, Nanjing Normal University, Nanjing 210009, People's Republic of China
| | - Haiyang Cui
- RWTH Aachen University, Templergraben 55, 52062 Aachen, Germany
| | - Yijie Sheng
- School of Food Science and Pharmaceutical Engineering, Nanjing Normal University, Nanjing 210009, People's Republic of China
| | - Jie Qiao
- School of Food Science and Pharmaceutical Engineering, Nanjing Normal University, Nanjing 210009, People's Republic of China
| | - Xiujuan Li
- School of Food Science and Pharmaceutical Engineering, Nanjing Normal University, Nanjing 210009, People's Republic of China
| | - He Huang
- School of Food Science and Pharmaceutical Engineering, Nanjing Normal University, Nanjing 210009, People's Republic of China
- School of Pharmaceutical Sciences, Nanjing Tech University, No. 30 South Puzhu Road, Nanjing 211816, People's Republic of China
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3
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Quartinello F, Subagia R, Zitzenbacher S, Reich J, Vielnascher R, Becher E, Hall M, Ribitsch D, Guebitz GM. Dihydropyrimidinase from Saccharomyces kluyveri can hydrolyse polyamides. Front Bioeng Biotechnol 2023; 11:1158226. [PMID: 37180040 PMCID: PMC10169691 DOI: 10.3389/fbioe.2023.1158226] [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: 02/03/2023] [Accepted: 04/14/2023] [Indexed: 05/15/2023] Open
Abstract
In Saccharomyces kluyveri, dihydropyrimidinase (DHPaseSK) is involved in the pyrimidine degradation pathway, which includes the reversible ring cleavage between nitrogen 3 and carbon 4 of 5,6-dihydrouracil. In this study, DPHaseSK was successfully cloned and expressed in E. coli BL-21 Gold (DE3) with and without affinity tags. Thereby, the Strep-tag enabled fastest purification and highest specific activity (9.5 ± 0.5 U/mg). The biochemically characterized DHPaseSK_Strep had similar kinetic parameters (Kcat/Km) on 5,6-dihydrouracil (DHU) and para-nitroacetanilide respectively, with 7,229 and 4060 M-1 s-1. The hydrolytic ability of DHPaseSK_Strep to polyamides (PA) was tested on PA consisting of monomers with different chain length (PA-6, PA-6,6, PA-4,6, PA-4,10 and PA-12). According to LC-MS/TOF analysis, DHPaseSK_Strep showed a preference for films containing the shorter chain monomers (e.g., PA-4,6). In contrast, an amidase from Nocardia farcinica (NFpolyA) showed some preference for PA consisting of longer chain monomers. In conclusion, in this work DHPaseSK_Strep was demonstrated to be able to cleave amide bonds in synthetic polymers, which can be an important basis for development of functionalization and recycling processes for polyamide containing materials.
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Affiliation(s)
- Felice Quartinello
- Austrian Centre of Industrial Biotechnology, Tulln an der Donau, Austria
- Department of Agrobiotechnology, Institute of Environmental Biotechnology, IFA-Tulln, University of Natural Resources and Life Sciences, Vienna, Austria
| | - Raditya Subagia
- Austrian Centre of Industrial Biotechnology, Tulln an der Donau, Austria
| | | | - Johanna Reich
- Austrian Centre of Industrial Biotechnology, Tulln an der Donau, Austria
| | - Robert Vielnascher
- Austrian Centre of Industrial Biotechnology, Tulln an der Donau, Austria
| | - Erik Becher
- Institute of Chemistry, University of Graz, Graz, Austria
| | - Mélanie Hall
- Institute of Chemistry, University of Graz, Graz, Austria
- BioHealth, University of Graz, Graz, Austria
| | - Doris Ribitsch
- Austrian Centre of Industrial Biotechnology, Tulln an der Donau, Austria
- Department of Agrobiotechnology, Institute of Environmental Biotechnology, IFA-Tulln, University of Natural Resources and Life Sciences, Vienna, Austria
| | - Georg M. Guebitz
- Austrian Centre of Industrial Biotechnology, Tulln an der Donau, Austria
- Department of Agrobiotechnology, Institute of Environmental Biotechnology, IFA-Tulln, University of Natural Resources and Life Sciences, Vienna, Austria
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Microbial Enzyme Biotechnology to Reach Plastic Waste Circularity: Current Status, Problems and Perspectives. Int J Mol Sci 2023; 24:ijms24043877. [PMID: 36835289 PMCID: PMC9967032 DOI: 10.3390/ijms24043877] [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: 01/22/2023] [Revised: 02/08/2023] [Accepted: 02/10/2023] [Indexed: 02/17/2023] Open
Abstract
The accumulation of synthetic plastic waste in the environment has become a global concern. Microbial enzymes (purified or as whole-cell biocatalysts) represent emerging biotechnological tools for waste circularity; they can depolymerize materials into reusable building blocks, but their contribution must be considered within the context of present waste management practices. This review reports on the prospective of biotechnological tools for plastic bio-recycling within the framework of plastic waste management in Europe. Available biotechnology tools can support polyethylene terephthalate (PET) recycling. However, PET represents only ≈7% of unrecycled plastic waste. Polyurethanes, the principal unrecycled waste fraction, together with other thermosets and more recalcitrant thermoplastics (e.g., polyolefins) are the next plausible target for enzyme-based depolymerization, even if this process is currently effective only on ideal polyester-based polymers. To extend the contribution of biotechnology to plastic circularity, optimization of collection and sorting systems should be considered to feed chemoenzymatic technologies for the treatment of more recalcitrant and mixed polymers. In addition, new bio-based technologies with a lower environmental impact in comparison with the present approaches should be developed to depolymerize (available or new) plastic materials, that should be designed for the required durability and for being susceptible to the action of enzymes.
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Nguyen LH, Nguyen BS, Le DT, Alomar TS, AlMasoud N, Ghotekar S, Oza R, Raizada P, Singh P, Nguyen VH. A concept for the biotechnological minimizing of emerging plastics, micro- and nano-plastics pollutants from the environment: A review. ENVIRONMENTAL RESEARCH 2023; 216:114342. [PMID: 36181894 DOI: 10.1016/j.envres.2022.114342] [Citation(s) in RCA: 9] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/18/2022] [Revised: 08/31/2022] [Accepted: 09/11/2022] [Indexed: 06/16/2023]
Abstract
Plastics, micro- and nano-plastics pollution are undoubtedly a severe and crucial ecological threat due to the durability of plastics and their destructive impacts on humans and wildlife. Most scientific investigations have addressed the classification, types, distribution, ingestion, fate, impacts, degradation, and various adverse effect of plastics. Heretofore, scanty reports have addressed implementing strategies for the remediation and mitigation of plastics. Therefore, in this paper, we review the current studies on the degradation of plastics, micro- and nano-plastics aided by microorganisms, and explore the relevant degradation properties and mechanisms. Diverse microorganisms are classified, such as bacteria, fungi, algae, cyanobacteria, wax worms, and enzymes that can decompose various plastics. Furthermore, bio-degradation is influenced by microbial features and environmental parameters; therefore, the ecological factors affecting plastic degradation and the resulting degradation consequences are discussed. In addition, the mechanisms underlying microbial-mediated plastic degradation are carefully studied. Finally, upcoming research directions and prospects for plastics degradation employing microorganisms are addressed. This review covers a comprehensive overview of the microorganism-assisted degradation of plastics, micro- and nano-plastics, and serves as a resource for future research into sustainable plastics pollution management methods.
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Affiliation(s)
- Lan Huong Nguyen
- Faculty of Biology and Environment, Ho Chi Minh City University of Food Industry, 140 Le Trong Tan Street, Tay Thanh Ward, Tan Phu District, Ho Chi Minh City, Viet Nam
| | - Ba-Son Nguyen
- Department of Renewable Energy, HCMC University of Technology and Education, Ho Chi Minh City, 700000, Viet Nam
| | - Duy-Tien Le
- Faculty of Pharmacy, Lac Hong University, Dong Nai Province, Viet Nam.
| | - Taghrid S Alomar
- Department of Chemistry, College of Science, Princess Nourah Bint Abdulrahman University, Riyadh, 11671, Saudi Arabia
| | - Najla AlMasoud
- Department of Chemistry, College of Science, Princess Nourah Bint Abdulrahman University, Riyadh, 11671, Saudi Arabia
| | - Suresh Ghotekar
- Department of Chemistry, Smt. Devkiba Mohansinhji Chauhan College of Commerce and Science, University of Mumbai, Silvassa, 396 230, Dadra and Nagar Haveli (UT), India.
| | - Rajeshwari Oza
- Department of Chemistry, S.N. Arts, D.J.M. Commerce and B.N.S. Science College, Savitribai Phule Pune University, Sangamner, 422 605, Maharashtra, India
| | - Pankaj Raizada
- School of Advanced Chemical Sciences, Shoolini University, Solan, Himachal Pradesh, 173229, India
| | - Pardeep Singh
- School of Advanced Chemical Sciences, Shoolini University, Solan, Himachal Pradesh, 173229, India
| | - Van-Huy Nguyen
- Chettinad Hospital and Research Institute, Chettinad Academy of Research and Education (CARE), Chengalpattu District, Kelambakkam, Tamil Nadu, 603103, India.
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Kumar V, Dhawan S, Bala R, Mohite SB, Singh P, Karpoormath R. Cu-catalysed transamidation of unactivated aliphatic amides. Org Biomol Chem 2022; 20:6931-6940. [PMID: 35983826 DOI: 10.1039/d2ob01152b] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Direct transamidation is gaining prominence as a ground-breaking technique that generates a wide variety of amides without the requirement of acid-amine coupling or other intermediate steps. However, transamidation of unactivated aliphatic amides, on the other hand, has been a long-standing issue in comparison to transamidation of activated amides. Herein, we report a transamidation approach of an unactivated aliphatic amide using a copper catalyst and chlorotrimethylsilane as an additive. In addition, we used transamidation as a tool for selective N-C(O) cleavage and O-C(O) formation to synthesise 2-substituted benzoxazoles and benzothiazoles. The reactions were carried out without using any solvents and offered wide substitution scope.
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Affiliation(s)
- Vishal Kumar
- Department of Pharmaceutical Chemistry, Discipline of Pharmaceutical Sciences, College of Health Sciences, University of KwaZulu-Natal (Westville), Durban-4000, South Africa.
| | - Sanjeev Dhawan
- Department of Pharmaceutical Chemistry, Discipline of Pharmaceutical Sciences, College of Health Sciences, University of KwaZulu-Natal (Westville), Durban-4000, South Africa.
| | - Renu Bala
- Department of Pharmaceutical Chemistry, Discipline of Pharmaceutical Sciences, College of Health Sciences, University of KwaZulu-Natal (Westville), Durban-4000, South Africa.
| | - Sachin Balaso Mohite
- Department of Pharmaceutical Chemistry, Discipline of Pharmaceutical Sciences, College of Health Sciences, University of KwaZulu-Natal (Westville), Durban-4000, South Africa.
| | - Parvesh Singh
- School of Chemistry and Physics, University of KwaZulu-Natal (Westville campus), Private Bag X01, Scottsville, Durban, South Africa.
| | - Rajshekhar Karpoormath
- Department of Pharmaceutical Chemistry, Discipline of Pharmaceutical Sciences, College of Health Sciences, University of KwaZulu-Natal (Westville), Durban-4000, South Africa.
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Jönsson C, Wei R, Biundo A, Landberg J, Schwarz Bour L, Pezzotti F, Toca A, M. Jacques L, Bornscheuer UT, Syrén P. Biocatalysis in the Recycling Landscape for Synthetic Polymers and Plastics towards Circular Textiles. CHEMSUSCHEM 2021; 14:4028-4040. [PMID: 33497036 PMCID: PMC8518944 DOI: 10.1002/cssc.202002666] [Citation(s) in RCA: 22] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/16/2020] [Revised: 01/26/2021] [Indexed: 05/05/2023]
Abstract
Although recovery of fibers from used textiles with retained material quality is desired, separation of individual components from polymer blends used in today's complex textile materials is currently not available at viable scale. Biotechnology could provide a solution to this pressing problem by enabling selective depolymerization of recyclable fibers of natural and synthetic origin, to isolate constituents or even recover monomers. We compiled experimental data for biocatalytic polymer degradation with a focus on synthetic polymers with hydrolysable links and calculated conversion rates to explore this path The analysis emphasizes that we urgently need major research efforts: beyond cellulose-based fibers, biotechnological-assisted depolymerization of plastics so far only works for polyethylene terephthalate, with degradation of a few other relevant synthetic polymer chains being reported. In contrast, by analyzing market data and emerging trends for synthetic fibers in the textile industry, in combination with numbers from used garment collection and sorting plants, it was shown that the use of difficult-to-recycle blended materials is rapidly growing. If the lack of recycling technology and production trend for fiber blends remains, a volume of more than 3400 Mt of waste will have been accumulated by 2030. This work highlights the urgent need to transform the textile industry from a biocatalytic perspective.
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Affiliation(s)
- Christina Jönsson
- RISE Research Institutes of SwedenArgongatan 30, Box 104SE-431 22MölndalSweden
| | - Ren Wei
- Department of Biotechnology and Enzyme CatalysisInstitute of BiochemistryUniversity of GreifswaldFelix-Hausdorff-Strasse 417487GreifswaldGermany
| | - Antonino Biundo
- School of Engineering Sciences in ChemistryBiotechnology and HealthKTH Royal Institute of TechnologyScience for Life LaboratoryTomtebodavägen 23, Box 1031 171 21 SolnaStockholmSweden
- School of Engineering Sciences in ChemistryBiotechnology and HealthDepartment of Fibre and Polymer TechnologyKTH Royal Institute of TechnologyTeknikringen 56–58100 44StockholmSweden
- Present address: REWOW srlVia Cardinale Agostino Ciasca 9701 24BariItaly
| | - Johan Landberg
- RISE Research Institutes of SwedenArgongatan 30, Box 104SE-431 22MölndalSweden
| | - Lisa Schwarz Bour
- RISE Research Institutes of SwedenArgongatan 30, Box 104SE-431 22MölndalSweden
| | - Fabio Pezzotti
- RISE Research Institutes of SwedenArgongatan 30, Box 104SE-431 22MölndalSweden
| | - Andreea Toca
- Swedish StockingsTyskbagargatan 7114 43StockholmSweden
- Present address: Hyper IslandVirkesvägen 2120 30StockholmSweden
| | - Les M. Jacques
- The LYCRA Company UK Limited60, Clooney Road, MaydownLondonderry N.BT47 6THIreland
| | - Uwe T. Bornscheuer
- Department of Biotechnology and Enzyme CatalysisInstitute of BiochemistryUniversity of GreifswaldFelix-Hausdorff-Strasse 417487GreifswaldGermany
| | - Per‐Olof Syrén
- School of Engineering Sciences in ChemistryBiotechnology and HealthKTH Royal Institute of TechnologyScience for Life LaboratoryTomtebodavägen 23, Box 1031 171 21 SolnaStockholmSweden
- School of Engineering Sciences in ChemistryBiotechnology and HealthDepartment of Fibre and Polymer TechnologyKTH Royal Institute of TechnologyTeknikringen 56–58100 44StockholmSweden
- KTH Royal Institute of TechnologySchool of Engineering Sciences in Chemistry, Biotechnology and Health Wallenberg Wood Science CenterTeknikringen 56–58100 44StockholmSweden
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Huang J, Xu Q, Liu Z, Jain N, Tyagi M, Wei DQ, Hong L. Controlling the Substrate Specificity of an Enzyme through Structural Flexibility by Varying the Salt-Bridge Density. Molecules 2021; 26:5693. [PMID: 34577164 PMCID: PMC8470667 DOI: 10.3390/molecules26185693] [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: 07/03/2021] [Revised: 09/03/2021] [Accepted: 09/16/2021] [Indexed: 11/17/2022] Open
Abstract
Many enzymes, particularly in one single family, with highly conserved structures and folds exhibit rather distinct substrate specificities. The underlying mechanism remains elusive, the resolution of which is of great importance for biochemistry, biophysics, and bioengineering. Here, we performed a neutron scattering experiment and molecular dynamics (MD) simulations on two structurally similar CYP450 proteins; CYP101 primarily catalyzes one type of ligands, then CYP2C9 can catalyze a large range of substrates. We demonstrated that it is the high density of salt bridges in CYP101 that reduces its structural flexibility, which controls the ligand access channel and the fluctuation of the catalytic pocket, thus restricting its selection on substrates. Moreover, we performed MD simulations on 146 different kinds of CYP450 proteins, spanning distinct biological categories including Fungi, Archaea, Bacteria, Protista, Animalia, and Plantae, and found the above mechanism generally valid. We demonstrated that, by fine changes of chemistry (salt-bridge density), the CYP450 superfamily can vary the structural flexibility of its member proteins among different biological categories, and thus differentiate their substrate specificities to meet the specific biological needs. As this mechanism is well-controllable and easy to be implemented, we expect it to be generally applicable in future enzymatic engineering to develop proteins of desired substrate specificities.
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Affiliation(s)
- Juan Huang
- State Key Laboratory of Microbial Metabolism, School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai 200240, China;
- Institute of Natural Sciences, Shanghai Jiao Tong University, Shanghai 200240, China;
| | - Qin Xu
- State Key Laboratory of Microbial Metabolism, School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai 200240, China;
| | - Zhuo Liu
- Institute of Natural Sciences, Shanghai Jiao Tong University, Shanghai 200240, China;
- School of Physics and Astronomy, Shanghai Jiao Tong University, Shanghai 200240, China
- Institute for Advanced Study, The Hong Kong University of Science and Technology, Hong Kong, China
| | - Nitin Jain
- Department of Biochemistry and Cellular and Molecular Biology, University of Tennessee, Knoxville, TN 37996, USA;
| | - Madhusudan Tyagi
- NIST Center for Neutron Research, National Institute of Standards and Technology (NIST), Gaithersburg, MD 20899, USA;
- Department of Materials Science and Engineering, University of Maryland, College Park, MD 20742, USA
| | - Dong-Qing Wei
- State Key Laboratory of Microbial Metabolism, School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai 200240, China;
- Peng Cheng Laboratory, Shenzhen 518055, China
| | - Liang Hong
- Institute of Natural Sciences, Shanghai Jiao Tong University, Shanghai 200240, China;
- School of Physics and Astronomy, Shanghai Jiao Tong University, Shanghai 200240, China
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Zhu B, Wang D, Wei N. Enzyme Discovery and Engineering for Sustainable Plastic Recycling. Trends Biotechnol 2021; 40:22-37. [PMID: 33676748 DOI: 10.1016/j.tibtech.2021.02.008] [Citation(s) in RCA: 76] [Impact Index Per Article: 25.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2020] [Revised: 02/09/2021] [Accepted: 02/10/2021] [Indexed: 10/22/2022]
Abstract
The drastically increasing amount of plastic waste is causing an environmental crisis that requires innovative technologies for recycling post-consumer plastics to achieve waste valorization while meeting environmental quality goals. Biocatalytic depolymerization mediated by enzymes has emerged as an efficient and sustainable alternative for plastic treatment and recycling. A variety of plastic-degrading enzymes have been discovered from microbial sources. Meanwhile, protein engineering has been exploited to modify and optimize plastic-degrading enzymes. This review highlights the recent trends and up-to-date advances in mining novel plastic-degrading enzymes through state-of-the-art omics-based techniques and improving the enzyme catalytic efficiency and stability via various protein engineering strategies. Future research prospects and challenges are also discussed.
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Affiliation(s)
- Baotong Zhu
- Department of Civil and Environmental Engineering and Earth Sciences, University of Notre Dame, 156 Fitzpatrick Hall, Notre Dame, Indiana 46556, USA
| | - Dong Wang
- Department of Computer Science and Engineering, University of Notre Dame, 156 Fitzpatrick Hall, Notre Dame, Indiana 46556, USA
| | - Na Wei
- Department of Civil and Environmental Engineering and Earth Sciences, University of Notre Dame, 156 Fitzpatrick Hall, Notre Dame, Indiana 46556, USA.
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Hints at the Applicability of Microalgae and Cyanobacteria for the Biodegradation of Plastics. SUSTAINABILITY 2020. [DOI: 10.3390/su122410449] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Massive plastic accumulation has been taking place across diverse landscapes since the 1950s, when large-scale plastic production started. Nowadays, societies struggle with continuously increasing concerns about the subsequent pollution and environmental stresses that have accompanied this plastic revolution. Degradation of used plastics is highly time-consuming and causes volumetric aggregation, mainly due to their high strength and bulky structure. The size of these agglomerations in marine and freshwater basins increases daily. Exposure to weather conditions and environmental microflora (e.g., bacteria and microalgae) can slowly corrode the plastic structure. As has been well documented in recent years, plastic fragments are widespread in marine basins and partially in main global rivers. These are potential sources of negative effects on global food chains. Cyanobacteria (e.g., Synechocystis sp. PCC 6803, and Synechococcus elongatus PCC 7942), which are photosynthetic microorganisms and were previously identified as blue-green algae, are currently under close attention for their abilities to capture solar energy and the greenhouse gas carbon dioxide for the production of high-value products. In the last few decades, these microorganisms have been exploited for different purposes (e.g., biofuels, antioxidants, fertilizers, and ‘superfood’ production). Microalgae (e.g., Chlamydomonas reinhardtii, and Phaeodactylum tricornutum) are also suitable for environmental and biotechnological applications based on the exploitation of solar light. Can photosynthetic bacteria and unicellular eukaryotic algae play a role for further scientific research in the bioremediation of plastics of different sizes present in water surfaces? In recent years, several studies have been targeting the utilization of microorganisms for plastic bioremediation. Among the different phyla, the employment of wild-type or engineered cyanobacteria may represent an interesting, environmentally friendly, and sustainable option.
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