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Mamtimin T, Ouyang X, Wu WM, Zhou T, Hou X, Khan A, Liu P, Zhao YL, Tang H, Criddle CS, Han H, Li X. Novel Feruloyl Esterase for the Degradation of Polyethylene Terephthalate (PET) Screened from the Gut Microbiome of Plastic-Degrading Mealworms ( Tenebrio Molitor Larvae). ENVIRONMENTAL SCIENCE & TECHNOLOGY 2024; 58:17717-17731. [PMID: 39315846 DOI: 10.1021/acs.est.4c01495] [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: 09/25/2024]
Abstract
Mealworms (Tenebrio molitor) larvae can degrade both plastics and lignocellulose through synergistic biological activities of their gut microbiota because they share similarities in chemical and physical properties. Here, a total of 428 genes encoding lignocellulose-degrading enzymes were screened from the gut microbiome of T. molitor larvae to identify poly(ethylene terephthalate) (PET)-degrading activities. Five genes were successfully expressed in E. coli, among which a feruloyl esterase-like enzyme named TmFae-PETase demonstrated the highest PET degradation activity, converting PET into MHET (0.7 mgMHETeq ·h-1·mgenzyme-1) and TPA (0.2 mgTPAeq ·h-1·mgenzyme-1) at 50 °C. TmFae-PETase showed a preference for the hydrolysis of ferulic acid methyl ester (MFA) in the presence of both PET and MFA. Site-directed mutagenesis and molecular dynamics simulations of TmFae-PETase revealed similar catalytic mechanisms for both PET and MFA. TmFae-PETase effectively depolymerized commercial PET, making it a promising candidate for application. Additionally, the known PET hydrolases IsPETase, FsC, and LCC also hydrolyzed MFA, indicating a potential origin of PET hydrolytic activity from its lignocellulosic-degrading abilities. This study provides an innovative strategy for screening PET-degrading enzymes identified from lignocellulose degradation-related enzymes within the gut microbiome of plastic-degrading mealworms. This discovery expands the existing pool of plastic-degrading enzymes available for resource recovery and bioremediation applications.
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Affiliation(s)
- Tursunay Mamtimin
- Ministry of Education Key Laboratory of Cell Activities and Stress Adaptations, School of Life Sciences, Lanzhou University, Lanzhou 730000, China
- Center for Grassland Microbiome, State Key Laboratory of Herbage Improvement and Grassland Agro-Ecosystems, College of Pastoral Agriculture Science and Technology, Lanzhou University, Lanzhou 730000, China
| | - Xingyu Ouyang
- State Key Laboratory of Microbial Metabolism, Joint International Research Laboratory of Metabolic and Developmental Sciences, School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai 200000, China
| | - Wei-Min Wu
- Department of Civil and Environmental Engineering, William & Cloy Codiga Resource Recovery Center, Stanford University, Stanford, California 94305, United States
| | - Tuoyu Zhou
- Ministry of Education Key Laboratory of Cell Activities and Stress Adaptations, School of Life Sciences, Lanzhou University, Lanzhou 730000, China
| | - Xiaoxiao Hou
- Ministry of Education Key Laboratory of Cell Activities and Stress Adaptations, School of Life Sciences, Lanzhou University, Lanzhou 730000, China
| | - Aman Khan
- Ministry of Education Key Laboratory of Cell Activities and Stress Adaptations, School of Life Sciences, Lanzhou University, Lanzhou 730000, China
- Ministry of Education, Key Laboratory of Saline-alkali Vegetation Ecology Restoration College of Life Sciences, Northeast Forestry University, Harbin 150040, China
| | - Pu Liu
- Ministry of Education Key Laboratory of Cell Activities and Stress Adaptations, School of Life Sciences, Lanzhou University, Lanzhou 730000, China
| | - Yi-Lei Zhao
- State Key Laboratory of Microbial Metabolism, Joint International Research Laboratory of Metabolic and Developmental Sciences, School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai 200000, China
| | - Hongzhi Tang
- State Key Laboratory of Microbial Metabolism, Joint International Research Laboratory of Metabolic and Developmental Sciences, School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai 200000, China
| | - Craig S Criddle
- Department of Civil and Environmental Engineering, William & Cloy Codiga Resource Recovery Center, Stanford University, Stanford, California 94305, United States
| | - Huawen Han
- Center for Grassland Microbiome, State Key Laboratory of Herbage Improvement and Grassland Agro-Ecosystems, College of Pastoral Agriculture Science and Technology, Lanzhou University, Lanzhou 730000, China
| | - Xiangkai Li
- Ministry of Education Key Laboratory of Cell Activities and Stress Adaptations, School of Life Sciences, Lanzhou University, Lanzhou 730000, China
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2
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Retnadhas S, Ducat DC, Hegg EL. Nature-Inspired Strategies for Sustainable Degradation of Synthetic Plastics. JACS AU 2024; 4:3323-3339. [PMID: 39328769 PMCID: PMC11423324 DOI: 10.1021/jacsau.4c00388] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 04/29/2024] [Revised: 08/10/2024] [Accepted: 08/12/2024] [Indexed: 09/28/2024]
Abstract
Synthetic plastics have become integral to our daily lives, yet their escalating production, limited biodegradability, and inadequate waste management contribute to environmental contamination. Biological plastic degradation is one promising strategy to address this pollution. The inherent chemical and physical properties of synthetic plastics, however, pose challenges for microbial enzymes, hindering the effective degradation and the development of a sustainable biological recycling process. This Perspective explores alternative, nature-inspired strategies designed to overcome some key limitations in currently available plastic-degrading enzymes. Nature's refined degradation pathways for natural polymers, such as cellulose, present a compelling framework for the development of efficient technologies for enzymatic plastic degradation. By drawing insights from nature, we propose a general strategy of employing substrate binding domains to improve targeting and multienzyme scaffolds to overcome enzymatic efficiency limitations. As one potential application, we outline a multienzyme pathway to upcycle polyethylene into alkenes. Employing nature-inspired strategies can present a path toward sustainable solution to the environmental impact of synthetic plastics.
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Affiliation(s)
- Sreeahila Retnadhas
- Department of Biochemistry and Molecular Biology, Michigan State University, East Lansing, Michigan 48824, United States
| | - Daniel C Ducat
- Department of Biochemistry and Molecular Biology, Michigan State University, East Lansing, Michigan 48824, United States
- MSU-DOE Plant Research Laboratory, Michigan State University, East Lansing, Michigan 48824, United States
| | - Eric L Hegg
- Department of Biochemistry and Molecular Biology, Michigan State University, East Lansing, Michigan 48824, United States
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Lu D, Chen Y, Jin S, Wu Q, Wu J, Liu J, Wang F, Deng L, Nie K. The evolution of cutinase Est1 based on the clustering strategy and its application for commercial PET bottles degradation. JOURNAL OF ENVIRONMENTAL MANAGEMENT 2024; 368:122217. [PMID: 39146645 DOI: 10.1016/j.jenvman.2024.122217] [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: 08/12/2024] [Accepted: 08/12/2024] [Indexed: 08/17/2024]
Abstract
The rapid increase in global plastic consumption, especially the worldwide use of polyethylene terephthalate (PET), has caused serious pollution problems. Due to the low recycling rate of PET, a substantial amount of waste accumulates in the environment, which prompts a growing focus on enzymatic degradation for its efficiency and environmentally friendliness. This study systematically designed and modified a cutinase, Est1 from Thermobifida alba AHK119, known for its potential of plastic-degradation at high temperatures. Additionally, the introduction of clustering algorithms provided the ability to understand and modify biomolecules, to accelerate the process of finding the optimal mutations. K-means was further proceeded based on the positive mutations. After comprehensive screening for thermostability and activity mutation sites, the dominant mutation Est1_5M (Est1 with the mutations of N213M, T215P, S115P, Q93A, and L91W) exhibited satisfying degradation ability for commercial PET bottles. The results showed that Est1_5M achieved a degradation rate of 90.84% in 72 h, 65-fold higher than the wild type. This study offers reliable theoretical and practical support for the development of efficient PET-degrading enzymes, providing a reference for plastic pollution management.
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Affiliation(s)
- Dong Lu
- National Energy R&D Center for Biorefinery, Beijing Key Laboratory of Bioprocess, College of Life Science and Technology, Beijing University of Chemical Technology, Beijing, 100029, China
| | - Ying Chen
- National Energy R&D Center for Biorefinery, Beijing Key Laboratory of Bioprocess, College of Life Science and Technology, Beijing University of Chemical Technology, Beijing, 100029, China
| | - Shuming Jin
- National Energy R&D Center for Biorefinery, Beijing Key Laboratory of Bioprocess, College of Life Science and Technology, Beijing University of Chemical Technology, Beijing, 100029, China
| | - Qiuyang Wu
- National Energy R&D Center for Biorefinery, Beijing Key Laboratory of Bioprocess, College of Life Science and Technology, Beijing University of Chemical Technology, Beijing, 100029, China
| | - Jinglong Wu
- National Energy R&D Center for Biorefinery, Beijing Key Laboratory of Bioprocess, College of Life Science and Technology, Beijing University of Chemical Technology, Beijing, 100029, China
| | - Junfeng Liu
- National Energy R&D Center for Biorefinery, Beijing Key Laboratory of Bioprocess, College of Life Science and Technology, Beijing University of Chemical Technology, Beijing, 100029, China
| | - Fang Wang
- National Energy R&D Center for Biorefinery, Beijing Key Laboratory of Bioprocess, College of Life Science and Technology, Beijing University of Chemical Technology, Beijing, 100029, China
| | - Li Deng
- National Energy R&D Center for Biorefinery, Beijing Key Laboratory of Bioprocess, College of Life Science and Technology, Beijing University of Chemical Technology, Beijing, 100029, China.
| | - Kaili Nie
- National Energy R&D Center for Biorefinery, Beijing Key Laboratory of Bioprocess, College of Life Science and Technology, Beijing University of Chemical Technology, Beijing, 100029, China.
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Ercolano C, Iacono R, Cafaro V, Pizzo E, Giovannelli D, Feuerriegel G, Streit WR, Strazzulli A, Moracci M. Biochemical Characterisation of Sis: A Distinct Thermophilic PETase with Enhanced NanoPET Substrate Hydrolysis and Thermal Stability. Int J Mol Sci 2024; 25:8120. [PMID: 39125688 PMCID: PMC11311821 DOI: 10.3390/ijms25158120] [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: 05/27/2024] [Revised: 07/12/2024] [Accepted: 07/23/2024] [Indexed: 08/12/2024] Open
Abstract
Polyethylene terephthalate (PET) degradation by enzymatic hydrolysis is significant for addressing plastic pollution and fostering sustainable waste management practices. Identifying thermophilic and thermostable PET hydrolases is particularly crucial for industrial bioprocesses, where elevated temperatures may enhance enzymatic efficiency and process kinetics. In this study, we present the discovery of a novel thermophilic and thermostable PETase enzyme named Sis, obtained through metagenomic sequence-based analysis. Sis exhibits robust activity on nanoPET substrates, demonstrating effectiveness at temperatures up to 70 °C and displaying exceptional thermal stability with a melting temperature (Tm) of 82 °C. Phylogenetically distinct from previously characterised PET hydrolases, Sis represents a valuable addition to the repertoire of enzymes suitable for PET degradation.
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Affiliation(s)
- Carmen Ercolano
- Department of Biology, University of Naples Federico II, Complesso Universitario di Monte S. Angelo, Via Cinthia 21, 80126 Naples, Italy; (C.E.); (R.I.); (V.C.); (E.P.); (D.G.); (M.M.)
| | - Roberta Iacono
- Department of Biology, University of Naples Federico II, Complesso Universitario di Monte S. Angelo, Via Cinthia 21, 80126 Naples, Italy; (C.E.); (R.I.); (V.C.); (E.P.); (D.G.); (M.M.)
- National Biodiversity Future Center (NBFC), 90133 Palermo, Italy
| | - Valeria Cafaro
- Department of Biology, University of Naples Federico II, Complesso Universitario di Monte S. Angelo, Via Cinthia 21, 80126 Naples, Italy; (C.E.); (R.I.); (V.C.); (E.P.); (D.G.); (M.M.)
| | - Elio Pizzo
- Department of Biology, University of Naples Federico II, Complesso Universitario di Monte S. Angelo, Via Cinthia 21, 80126 Naples, Italy; (C.E.); (R.I.); (V.C.); (E.P.); (D.G.); (M.M.)
- Centro Servizi Metrologici e Tecnologici Avanzati (CeSMA), University of Naples Federico II, 80126 Naples, Italy
| | - Donato Giovannelli
- Department of Biology, University of Naples Federico II, Complesso Universitario di Monte S. Angelo, Via Cinthia 21, 80126 Naples, Italy; (C.E.); (R.I.); (V.C.); (E.P.); (D.G.); (M.M.)
- National Biodiversity Future Center (NBFC), 90133 Palermo, Italy
- Institute for Marine Biological Resources and Biotechnologies, Italian National Research Council, CNR-IRBIM, 60125 Ancona, Italy
- Department of Marine and Coastal Science, Rutgers University, New Brunswick, NJ 08901, USA
- Marine Chemistry and Geochemistry Department, Woods Hole Oceanographic Institution, Woods Hole, MA 02543, USA
- Earth-Life Science Institute (ELSI), Tokyo Institute of Technology, Tokyo 152-8552, Japan
| | - Golo Feuerriegel
- Department of Microbiology and Biotechnology, University of Hamburg, 22609 Hamburg, Germany; (G.F.); (W.R.S.)
| | - Wolfgang R. Streit
- Department of Microbiology and Biotechnology, University of Hamburg, 22609 Hamburg, Germany; (G.F.); (W.R.S.)
| | - Andrea Strazzulli
- Department of Biology, University of Naples Federico II, Complesso Universitario di Monte S. Angelo, Via Cinthia 21, 80126 Naples, Italy; (C.E.); (R.I.); (V.C.); (E.P.); (D.G.); (M.M.)
- National Biodiversity Future Center (NBFC), 90133 Palermo, Italy
| | - Marco Moracci
- Department of Biology, University of Naples Federico II, Complesso Universitario di Monte S. Angelo, Via Cinthia 21, 80126 Naples, Italy; (C.E.); (R.I.); (V.C.); (E.P.); (D.G.); (M.M.)
- National Biodiversity Future Center (NBFC), 90133 Palermo, Italy
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5
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Pham VHT, Kim J, Chang S. A Valuable Source of Promising Extremophiles in Microbial Plastic Degradation. Polymers (Basel) 2024; 16:2109. [PMID: 39125136 PMCID: PMC11314448 DOI: 10.3390/polym16152109] [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: 05/23/2024] [Revised: 07/01/2024] [Accepted: 07/22/2024] [Indexed: 08/12/2024] Open
Abstract
Plastics have accumulated in open environments, such as oceans, rivers, and land, for centuries, but their effect has been of concern for only decades. Plastic pollution is a global challenge at the forefront of public awareness worldwide due to its negative effects on ecological systems, animals, human health, and national economies. Therefore, interest has increased regarding specific circular economies for the development of plastic production and the investigation of green technologies for plastic degradation after use on an appropriate timescale. Moreover, biodegradable plastics have been found to contain potential new hazards compared with conventional plastics due to the physicochemical properties of the polymers involved. Recently, plastic biodegradation was defined as microbial conversion using functional microorganisms and their enzymatic systems. This is a promising strategy for depolymerizing organic components into carbon dioxide, methane, water, new biomass, and other higher value bioproducts under both oxic and anoxic conditions. This study reviews microplastic pollution, the negative consequences of plastic use, and the current technologies used for plastic degradation and biodegradation mediated by microorganisms with their drawbacks; in particular, the important and questionable role of extremophilic multi-enzyme-producing bacteria in synergistic systems of plastic decomposition is discussed. This study emphasizes the key points for enhancing the plastic degradation process using extremophiles, such as cell hydrophobicity, amyloid protein, and other relevant factors. Bioprospecting for novel mechanisms with unknown information about the bioproducts produced during the plastic degradation process is also mentioned in this review with the significant goals of CO2 evolution and increasing H2/CH4 production in the future. Based on the potential factors that were analyzed, there may be new ideas for in vitro isolation techniques for unculturable/multiple-enzyme-producing bacteria and extremophiles from various polluted environments.
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Affiliation(s)
- Van Hong Thi Pham
- Department of Environmental Energy Engineering, College of Creative Engineering, Kyonggi University, Suwon 16227, Republic of Korea;
- Department of Life Science, College of Natural Science, Kyonggi University, Suwon 16227, Republic of Korea
| | - Jaisoo Kim
- Department of Life Science, College of Natural Science, Kyonggi University, Suwon 16227, Republic of Korea
| | - Soonwoong Chang
- Department of Environmental Energy Engineering, College of Creative Engineering, Kyonggi University, Suwon 16227, Republic of Korea;
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6
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Jin J, Jia Z. Characterization of Potential Plastic-Degradation Enzymes from Marine Bacteria. ACS OMEGA 2024; 9:32185-32192. [PMID: 39072070 PMCID: PMC11270687 DOI: 10.1021/acsomega.4c04843] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/22/2024] [Revised: 06/29/2024] [Accepted: 07/05/2024] [Indexed: 07/30/2024]
Abstract
Polyethylene terephthalate (PET) and polyethylene (PE) are prominent polymer materials that comprise a significant portion of commercial plastic waste. Their durability and slow degradation rate have resulted in significant accumulation of plastic on Earth. In a recent study, macrotranscriptomic profiling of a reconstituted marine bacterial community identified 10 putative enzymes capable of directly acting on PE or PET (PEases or PETases). Among these enzymes, three recombinant proteins were reported to possess PE degradation activity. To select potential plastic degrading enzyme candidates for protein engineering efforts, we expressed and purified eight out of the 10 candidates, excluding two due to poor expression and/or solubility. Notably, several candidate proteins displayed significant esterase activity on p-nitrophenyl butyrate and exhibited unexpected thermostability despite their marine origin. Additionally, we observed dose- and time-dependent hydrolytic activity on the PET trimer substrate. Structural analysis and mutagenesis of a candidate protein confirmed the presence of catalytic triad residues, classifying it as an esterase. Furthermore, we elucidated the structural importance of the two disulfide bonds. Through point mutation experiments, we observed an enhanced hydrolytic activity of a selected enzyme candidate on PET nanoparticles. Our findings challenge the classification of the enzymes directly acting on PE and highlight the significance and complexity of validating PE degradation enzymes identified through metagenomic analysis.
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Affiliation(s)
- Jin Jin
- Department of Biomedical
and Molecular Sciences, Queen’s University, 18 Stuart Street, Kingston, ON KL7
3N6, Canada
| | - Zongchao Jia
- Department of Biomedical
and Molecular Sciences, Queen’s University, 18 Stuart Street, Kingston, ON KL7
3N6, Canada
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Shalem A, Yehezkeli O, Fishman A. Enzymatic degradation of polylactic acid (PLA). Appl Microbiol Biotechnol 2024; 108:413. [PMID: 38985324 PMCID: PMC11236915 DOI: 10.1007/s00253-024-13212-4] [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: 04/03/2024] [Revised: 05/28/2024] [Accepted: 05/29/2024] [Indexed: 07/11/2024]
Abstract
Environmental concerns arising from the increasing use of polluting plastics highlight polylactic acid (PLA) as a promising eco-friendly alternative. PLA is a biodegradable polyester that can be produced through the fermentation of renewable resources. Together with its excellent properties, suitable for a wide range of applications, the use of PLA has increased significantly over the years and is expected to further grow. However, insufficient degradability under natural conditions emphasizes the need for the exploration of biodegradation mechanisms, intending to develop more efficient techniques for waste disposal and recycling or upcycling. Biodegradation occurs through the secretion of depolymerizing enzymes, mainly proteases, lipases, cutinases, and esterases, by various microorganisms. This review focuses on the enzymatic degradation of PLA and presents different enzymes that were isolated and purified from natural PLA-degrading microorganisms, or recombinantly expressed. The review depicts the main characteristics of the enzymes, including recent advances and analytical methods used to evaluate enantiopurity and depolymerizing activity. While complete degradation of solid PLA particles is still difficult to achieve, future research and improvement of enzyme properties may provide an avenue for the development of advanced procedures for PLA degradation and upcycling, utilizing its building blocks for further applications as envisaged by circular economy principles. KEY POINTS: • Enzymes can be promisingly utilized for PLA upcycling. • Natural and recombinant PLA depolymerases and methods for activity evaluation are summarized. • Approaches to improve enzymatic degradation of PLA are discussed.
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Affiliation(s)
- Adi Shalem
- Department of Biotechnology and Food Engineering, Technion-Israel Institute of Technology, 3200003, Haifa, Israel
| | - Omer Yehezkeli
- Department of Biotechnology and Food Engineering, Technion-Israel Institute of Technology, 3200003, Haifa, Israel
| | - Ayelet Fishman
- Department of Biotechnology and Food Engineering, Technion-Israel Institute of Technology, 3200003, Haifa, Israel.
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8
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Han Z, Nina MRH, Zhang X, Huang H, Fan D, Bai Y. Discovery and characterization of two novel polyethylene terephthalate hydrolases: One from a bacterium identified in human feces and one from the Streptomyces genus. JOURNAL OF HAZARDOUS MATERIALS 2024; 472:134532. [PMID: 38749251 DOI: 10.1016/j.jhazmat.2024.134532] [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: 12/24/2023] [Revised: 05/01/2024] [Accepted: 05/02/2024] [Indexed: 05/30/2024]
Abstract
Polyethylene terephthalate (PET) is widely used for various industrial applications. However, owing to its extremely slow breakdown rate, PET accumulates as plastic trash, which negatively affects the environment and human health. Here, we report two novel PET hydrolases: PpPETase from Pseudomonas paralcaligenes MRCP1333, identified in human feces, and ScPETase from Streptomyces calvus DSM 41452. These two enzymes can decompose various PET materials, including semicrystalline PET powders (Cry-PET) and low-crystallinity PET films (gf-PET). By structure-guided engineering, two variants, PpPETaseY239R/F244G/Y250G and ScPETaseA212C/T249C/N195H/N243K were obtained that decompose Cry-PET 3.1- and 1.9-fold faster than their wild-type enzymes, respectively. The co-expression of ScPETase and mono-(2-hydroxyethyl) terephthalate hydrolase from Ideonella sakaiensis (IsMHETase) resulted in 1.4-fold more degradation than the single enzyme system. This engineered strain degraded Cry-PET and gf-PET by more than 40% and 6%, respectively, after 30 d. The concentrations of terephthalic acid (TPA) in the Cry-PET and gf-PET degradation products were 37.7% and 25.6%, respectively. The discovery of these two novel PET hydrolases provides opportunities to create more powerful biocatalysts for PET biodegradation.
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Affiliation(s)
- Zhengyang Han
- State Key Laboratory of Bioreactor Engineering, Shanghai Collaborative Innovation Center for Biomanufacturing, East China University of Science and Technology, Shanghai 200237, China
| | - Mario Roque Huanca Nina
- State Key Laboratory of Bioreactor Engineering, Shanghai Collaborative Innovation Center for Biomanufacturing, East China University of Science and Technology, Shanghai 200237, China
| | - Xiaoyan Zhang
- State Key Laboratory of Bioreactor Engineering, Shanghai Collaborative Innovation Center for Biomanufacturing, East China University of Science and Technology, Shanghai 200237, China
| | - Hanyao Huang
- State Key Laboratory of Bioreactor Engineering, Shanghai Collaborative Innovation Center for Biomanufacturing, East China University of Science and Technology, Shanghai 200237, China
| | - Daidi Fan
- Shaanxi R&D Centre of Biomaterials and Fermentation Engineering, School of Chemical Engineering, Northwest University, Xi'an, Shaanxi 710069, China
| | - Yunpeng Bai
- State Key Laboratory of Bioreactor Engineering, Shanghai Collaborative Innovation Center for Biomanufacturing, East China University of Science and Technology, Shanghai 200237, China.
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9
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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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10
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Qian Y, Huang L, Yan P, Wang X, Luo Y. Biofilms on Plastic Debris and the Microbiome. Microorganisms 2024; 12:1362. [PMID: 39065130 PMCID: PMC11278848 DOI: 10.3390/microorganisms12071362] [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: 05/27/2024] [Revised: 06/18/2024] [Accepted: 06/25/2024] [Indexed: 07/28/2024] Open
Abstract
Plastic pollution has become a global environmental problem, and the large number of microorganisms attached to plastic debris in the environment has become a hot topic due to their rapid response to pollutants and environmental changes. In this study, we used high-throughput sequencing to investigate the microbial community structure of and explore the metagenome in the biofilm of two types of plastic debris, polystyrene (PS) and polyethylene terephthalate (PET), and compared them with a water sample collected at the sampling site. The phylum Proteobacteria dominated both the PET and PS samples, at 93.43% and 65.95%, respectively. The metagenome data indicated that the biofilm is enriched with a number of hydrocarbon (petroleum, microplastics, etc.) degrading genes. Our results show that the type of plastic determined the bacterial community structure of the biofilm, while the environment had relatively little effect.
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Affiliation(s)
- Yiqian Qian
- Key Laboratory of the Ministry of Education for Coastal and Wetland Ecosystems, Xiamen University, Xiamen 361102, China
- Xiamen City Key Laboratory of Urban Sea Ecological Conservation and Restoration (USER), Xiamen University, Xiamen 361102, China
- College of the Environment and Ecology, Xiamen University, Xiamen 361102, China
| | - Lingfeng Huang
- Key Laboratory of the Ministry of Education for Coastal and Wetland Ecosystems, Xiamen University, Xiamen 361102, China
- Xiamen City Key Laboratory of Urban Sea Ecological Conservation and Restoration (USER), Xiamen University, Xiamen 361102, China
- College of the Environment and Ecology, Xiamen University, Xiamen 361102, China
| | - Pei Yan
- Key Laboratory of the Ministry of Education for Coastal and Wetland Ecosystems, Xiamen University, Xiamen 361102, China
- College of the Environment and Ecology, Xiamen University, Xiamen 361102, China
| | - Xinhong Wang
- College of the Environment and Ecology, Xiamen University, Xiamen 361102, China
- State Key Laboratory of Marine Environmental Science, Xiamen University, Xiamen 361102, China
| | - Yuanrong Luo
- Key Laboratory of the Ministry of Education for Coastal and Wetland Ecosystems, Xiamen University, Xiamen 361102, China
- Xiamen City Key Laboratory of Urban Sea Ecological Conservation and Restoration (USER), Xiamen University, Xiamen 361102, China
- College of the Environment and Ecology, Xiamen University, Xiamen 361102, China
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11
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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 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] [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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12
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Amanna R, Rakshit SK. Review of nomenclature and methods of analysis of polyethylene terephthalic acid hydrolyzing enzymes activity. Biodegradation 2024; 35:341-360. [PMID: 37688750 DOI: 10.1007/s10532-023-10048-z] [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: 03/07/2023] [Accepted: 08/15/2023] [Indexed: 09/11/2023]
Abstract
Enzymatic degradation of polyethylene terephthalic acid (PET) has been gaining increasing importance. This has resulted in a significant increase in the search for newer enzymes and the development of more efficient enzyme-based systems. Due to the lack of a standard screening process, screening new enzymes has relied on other assays to determine the presence of esterase activity. This, in turn, has led to various nomenclatures and methods used to describe them and measure their activity. Since all PET-hydrolyzing enzymes are α/β hydrolases, they catalyze a serine nucleophilic attack and cleave an ester bond. They are lipases, esterases, cutinases and hydrolases. This has been used interchangeably, leading to difficulties while comparing results and evaluating progress. This review discusses the varied enzyme nomenclature being adapted, the different assays and analysis methods reported, and the strategies used to increase PET-hydrolyzing enzyme efficiency. A section on the various ways to quantify PET hydrolysis is also covered.
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Affiliation(s)
- Ruth Amanna
- Department of Biotechnology, Lakehead University, Thunder Bay, ON, Canada
- Biorefining Research Institute (BRI), Lakehead University, Thunder Bay, ON, Canada
| | - Sudip K Rakshit
- Department of Biotechnology, Lakehead University, Thunder Bay, ON, Canada.
- Biorefining Research Institute (BRI), Lakehead University, Thunder Bay, ON, Canada.
- Department of Chemical Engineering, Lakehead University, Thunder Bay, ON, Canada.
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13
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Huang JP, Yun ST, Zhao JX, Wang XT, Wang XC, Guo XY, San DM, Zhou YX. The two-step strategy for enhancing the specific activity and thermostability of alginate lyase AlyG2 with mechanism for improved thermostability. Int J Biol Macromol 2024; 273:132685. [PMID: 38823749 DOI: 10.1016/j.ijbiomac.2024.132685] [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: 01/02/2024] [Revised: 04/01/2024] [Accepted: 05/24/2024] [Indexed: 06/03/2024]
Abstract
To overcome the trade-off challenge encountered in the engineering of alginate lyase AlyG2 from Seonamhaeicola algicola Gy8T and to expand its potential industrial applications, we devised a two-step strategy encompassing activity enhancement followed by thermal stability engineering. To enhance the specific activity of efficient AlyG2, we strategically substituted residues with bulky steric hindrance proximal to the active pocket with glycine or alanine. This led to the generation of three promising positive mutants, with particular emphasis on the T91S mutant, exhibiting a 1.91-fold specific activity compared to the wild type. To mitigate the poor thermal stability of T91S, mutants with negative ΔΔG values in the thermal flexibility region were screened out. Notably, the S72Ya mutant not only displayed 17.96 % further increase in specific activity but also exhibited improved stability compared to T91S, manifesting as a remarkable 30.97 % increase in relative activity following a 1-hour incubation at 42 °C. Furthermore, enhanced kinetic stability was observed. To gain deeper insights into the mechanism underlying the enhanced thermostability of the S72Ya mutant, we conducted molecular dynamics simulations, principal component analysis (PCA), dynamic cross-correlation map (DCCM), and free energy landscape (FEL) analysis. The results unveiled a reduction in the flexibility of the surface loop, a stronger correlation dynamic and a narrower motion subspace in S72Ya system, along with the formation of more stable hydrogen bonds. Collectively, our findings suggest amino acids substitutions resulting in smaller side chains proximate to the active site can positively impact enzyme activity, while reducing the flexibility of surface loops emerges as a pivotal factor in conferring thermal stability. These insights offer valuable guidance and a framework for the engineering of other enzyme types.
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Affiliation(s)
- Jin-Ping Huang
- Marine College, Shandong University, Weihai, Shandong 264209, China
| | - Shuai-Ting Yun
- Marine College, Shandong University, Weihai, Shandong 264209, China
| | - Jin-Xin Zhao
- Monash Biomedicine Discovery Institute, Infection Program and Department of Microbiology, Monash University, Clayton, Victoria 3800, Australia
| | - Xue-Ting Wang
- Marine College, Shandong University, Weihai, Shandong 264209, China
| | - Xiao-Chen Wang
- Marine College, Shandong University, Weihai, Shandong 264209, China
| | - Xiang-Yi Guo
- SDU-ANU joint science college, Shandong University, Weihai, Shandong 264209, China
| | - Dong-Mei San
- Marine College, Shandong University, Weihai, Shandong 264209, China
| | - Yan-Xia Zhou
- Marine College, Shandong University, Weihai, Shandong 264209, China
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14
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Xiong Z, Zhang Y, Chen X, Sha A, Xiao W, Luo Y, Han J, Li Q. Soil Microplastic Pollution and Microbial Breeding Techniques for Green Degradation: A Review. Microorganisms 2024; 12:1147. [PMID: 38930528 PMCID: PMC11205638 DOI: 10.3390/microorganisms12061147] [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: 05/14/2024] [Revised: 05/28/2024] [Accepted: 05/30/2024] [Indexed: 06/28/2024] Open
Abstract
Microplastics (MPs), found in many places around the world, are thought to be more detrimental than other forms of plastics. At present, physical, chemical, and biological methods are being used to break down MPs. Compared with physical and chemical methods, biodegradation methods have been extensively studied by scholars because of their advantages of greenness and sustainability. There have been numerous reports in recent years summarizing the microorganisms capable of degrading MPs. However, there is a noticeable absence of a systematic summary on the technology for breeding strains that can degrade MPs. This paper summarizes the strain-breeding technology of MP-degrading strains for the first time in a systematic way, which provides a new idea for the breeding of efficient MP-degrading strains. Meanwhile, potential techniques for breeding bacteria that can degrade MPs are proposed, providing a new direction for selecting and breeding MP-degrading bacteria in the future. In addition, this paper reviews the sources and pollution status of soil MPs, discusses the current challenges related to the biodegradation of MPs, and emphasizes the safety of MP biodegradation.
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Affiliation(s)
| | | | | | | | | | | | - Jialiang Han
- Key Laboratory of Coarse Cereal Processing, Ministry of Agriculture and Rural Affairs, Sichuan Engineering & Technology Research Center of Coarse Cereal Industrialization, School of Food and Biological Engineering, Chengdu University, No. 2025, Chengluo Avenue, Longquanyi District, Chengdu 610106, China; (Z.X.); (Y.Z.); (X.C.); (A.S.); (W.X.); (Y.L.)
| | - Qiang Li
- Key Laboratory of Coarse Cereal Processing, Ministry of Agriculture and Rural Affairs, Sichuan Engineering & Technology Research Center of Coarse Cereal Industrialization, School of Food and Biological Engineering, Chengdu University, No. 2025, Chengluo Avenue, Longquanyi District, Chengdu 610106, China; (Z.X.); (Y.Z.); (X.C.); (A.S.); (W.X.); (Y.L.)
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15
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Carr CM, Göttsch F, de Oliveira BFR, Murcia PAS, Jackson SA, Wei R, Clarke DJ, Bornscheuer UT, Dobson ADW. Identification and expression of MarCE, a marine carboxylesterase with synthetic ester-degrading activity. Microb Biotechnol 2024; 17:e14479. [PMID: 38881500 PMCID: PMC11180994 DOI: 10.1111/1751-7915.14479] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2024] [Revised: 04/15/2024] [Accepted: 04/30/2024] [Indexed: 06/18/2024] Open
Abstract
Carboxylic ester hydrolases with the capacity to degrade polyesters are currently highly sought after for their potential use in the biological degradation of PET and other chemically synthesized polymers. Here, we describe MarCE, a carboxylesterase family protein identified via genome mining of a Maribacter sp. isolate from the marine sponge Stelligera stuposa. Based on phylogenetic analysis, MarCE and its closest relatives belong to marine-associated genera from the Cytophaga-Flavobacterium-Bacteroides taxonomic group and appear evolutionarily distinct to any homologous carboxylesterases that have been studied to date in terms of structure or function. Molecular docking revealed putative binding of BHET, a short-chain PET derivative, onto the predicted MarCE three-dimensional structure. The synthetic ester-degrading activity of MarCE was subsequently confirmed by MarCE-mediated hydrolysis of 2 mM BHET substrate, indicated by the release of its breakdown products MHET and TPA, which were measured, respectively, as 1.28 and 0.12 mM following 2-h incubation at 30°C. The findings of this study provide further insight into marine carboxylic ester hydrolases, which have the potential to display unique functional plasticity resulting from their adaptation to complex and fluctuating marine environmentsw.
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Affiliation(s)
- Clodagh M. Carr
- School of MicrobiologyUniversity College CorkCorkIreland
- SSPC‐SFI Research Centre for PharmaceuticalsUniversity College CorkCorkIreland
| | - Frederike Göttsch
- Department of Biotechnology and Enzyme Catalysis, Institute of BiochemistryUniversity of GreifswaldGreifswaldGermany
| | | | - Pedro A. Sánchez Murcia
- Laboratory of Computer‐Aided Molecular Design, Division of Medicinal Chemistry, Otto‐Loewi Research CenterMedical University of GrazGrazAustria
- BioTechMed‐GrazGrazAustria
| | - Stephen A. Jackson
- School of MicrobiologyUniversity College CorkCorkIreland
- SSPC‐SFI Research Centre for PharmaceuticalsUniversity College CorkCorkIreland
- Environmental Research InstituteUniversity College CorkCorkIreland
| | - Ren Wei
- Department of Biotechnology and Enzyme Catalysis, Institute of BiochemistryUniversity of GreifswaldGreifswaldGermany
| | - David J. Clarke
- School of MicrobiologyUniversity College CorkCorkIreland
- SSPC‐SFI Research Centre for PharmaceuticalsUniversity College CorkCorkIreland
- APC Microbiome IrelandUniversity College CorkCorkIreland
| | - Uwe T. Bornscheuer
- Department of Biotechnology and Enzyme Catalysis, Institute of BiochemistryUniversity of GreifswaldGreifswaldGermany
| | - Alan D. W. Dobson
- School of MicrobiologyUniversity College CorkCorkIreland
- SSPC‐SFI Research Centre for PharmaceuticalsUniversity College CorkCorkIreland
- Environmental Research InstituteUniversity College CorkCorkIreland
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16
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Ji J, Pei J, Ding F, Zeng C, Zhou J, Dong W, Cui Z, Yan X. Isolation and characterization of polyester polyurethane-degrading bacterium Bacillus sp. YXP1. ENVIRONMENTAL RESEARCH 2024; 249:118468. [PMID: 38354881 DOI: 10.1016/j.envres.2024.118468] [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: 09/12/2023] [Revised: 02/05/2024] [Accepted: 02/10/2024] [Indexed: 02/16/2024]
Abstract
Microorganisms have the potential to be applied for the degradation or depolymerization of polyurethane (PU) and other plastic waste, which have attracted global attention. The appropriate strain or enzyme that can effectively degrade PU is the key to treat PU plastic wastes by biological methods. Here, a polyester PU-degrading bacterium Bacillus sp. YXP1 was isolated and identified from a plastic landfill. Three PU substrates with increasing structure complexities, including Impranil DLN, poly (1,4-butylene adipate)-based PU (PBA-PU), and polyester PU foam, were used to evaluate the degradation capacity of Bacillus sp. YXP1. Under optimal conditions, strain YXP1 could completely degrade 0.5% Impranil DLN within 7 days. After 30 days, the weight loss of polyester PU foam by strain YXP1 was as high as 42.1%. In addition, PBA-PU was applied for degradation pathway analysis due to its clear composition and chemical structure. Five degradation intermediates of PBA-PU were identified, including 4,4'-methylenedianiline (MDA), 1,4-butanediol, adipic acid, and two MDA derivates, indicating that strain YXP1 could depolymerize PBA-PU by the hydrolysis of ester and urethane bonds. Furthermore, the extracellular enzymes produced by strain YXP1 could hydrolyze PBA-PU to generate MDA. Together, this study provides a potential bacterium for the biological treatment of PU plastic wastes and for the mining of functional enzymes.
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Affiliation(s)
- Junbin Ji
- Key Laboratory of Agricultural Environmental Microbiology, Ministry of Agriculture, College of Life Sciences, Nanjing Agricultural University, Nanjing, Jiangsu 210095, China; Nanjing Key Laboratory of Quality and Safety of Agricultural Products, College of Food Science, Nanjing XiaoZhuang University, Nanjing, Jiangsu 211171, China
| | - Jing Pei
- Key Laboratory of Agricultural Environmental Microbiology, Ministry of Agriculture, College of Life Sciences, Nanjing Agricultural University, Nanjing, Jiangsu 210095, China
| | - Fanghui Ding
- Key Laboratory of Agricultural Environmental Microbiology, Ministry of Agriculture, College of Life Sciences, Nanjing Agricultural University, Nanjing, Jiangsu 210095, China
| | - Caiting Zeng
- Key Laboratory of Agricultural Environmental Microbiology, Ministry of Agriculture, College of Life Sciences, Nanjing Agricultural University, Nanjing, Jiangsu 210095, China
| | - Jie Zhou
- Key Laboratory for Waste Plastics Biocatalytic Degradation and Recycling, College of Biotechnology and Pharmaceutical Engineering, Nanjing Tech University, Nanjing, 211800, China
| | - Weiliang Dong
- Key Laboratory for Waste Plastics Biocatalytic Degradation and Recycling, College of Biotechnology and Pharmaceutical Engineering, Nanjing Tech University, Nanjing, 211800, China
| | - Zhongli Cui
- Key Laboratory of Agricultural Environmental Microbiology, Ministry of Agriculture, College of Life Sciences, Nanjing Agricultural University, Nanjing, Jiangsu 210095, China
| | - Xin Yan
- Key Laboratory of Agricultural Environmental Microbiology, Ministry of Agriculture, College of Life Sciences, Nanjing Agricultural University, Nanjing, Jiangsu 210095, China.
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17
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Rahmati F, Sethi D, Shu W, Asgari Lajayer B, Mosaferi M, Thomson A, Price GW. Advances in microbial exoenzymes bioengineering for improvement of bioplastics degradation. CHEMOSPHERE 2024; 355:141749. [PMID: 38521099 DOI: 10.1016/j.chemosphere.2024.141749] [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: 09/06/2023] [Revised: 03/06/2024] [Accepted: 03/16/2024] [Indexed: 03/25/2024]
Abstract
Plastic pollution has become a major global concern, posing numerous challenges for the environment and wildlife. Most conventional ways of plastics degradation are inefficient and cause great damage to ecosystems. The development of biodegradable plastics offers a promising solution for waste management. These plastics are designed to break down under various conditions, opening up new possibilities to mitigate the negative impact of traditional plastics. Microbes, including bacteria and fungi, play a crucial role in the degradation of bioplastics by producing and secreting extracellular enzymes, such as cutinase, lipases, and proteases. However, these microbial enzymes are sensitive to extreme environmental conditions, such as temperature and acidity, affecting their functions and stability. To address these challenges, scientists have employed protein engineering and immobilization techniques to enhance enzyme stability and predict protein structures. Strategies such as improving enzyme and substrate interaction, increasing enzyme thermostability, reinforcing the bonding between the active site of the enzyme and substrate, and refining enzyme activity are being utilized to boost enzyme immobilization and functionality. Recently, bioengineering through gene cloning and expression in potential microorganisms, has revolutionized the biodegradation of bioplastics. This review aimed to discuss the most recent protein engineering strategies for modifying bioplastic-degrading enzymes in terms of stability and functionality, including enzyme thermostability enhancement, reinforcing the substrate binding to the enzyme active site, refining with other enzymes, and improvement of enzyme surface and substrate action. Additionally, discovered bioplastic-degrading exoenzymes by metagenomics techniques were emphasized.
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Affiliation(s)
- Farzad Rahmati
- Department of Microbiology, Faculty of Science, Qom Branch, Islamic Azad University (IAU), Qom 37185364, Iran
| | - Debadatta Sethi
- Sugarcane Research Station, Odisha University of Agriculture and Technology, Nayagarh, India
| | - Weixi Shu
- Faculty of Agriculture, Dalhousie University, Truro, NS, B2N 5E3, Canada
| | | | - Mohammad Mosaferi
- Health and Environment Research Center, Tabriz Health Services Management Research Center, Tabriz University of Medical Sciences, Tabriz, Iran
| | - Allan Thomson
- Perennia Food and Agriculture Corporation., 173 Dr. Bernie MacDonald Dr., Bible Hill, Truro, NS, B6L 2H5, Canada
| | - G W Price
- Faculty of Agriculture, Dalhousie University, Truro, NS, B2N 5E3, Canada.
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18
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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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19
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Choi J, Kim H, Ahn YR, Kim M, Yu S, Kim N, Lim SY, Park JA, Ha SJ, Lim KS, Kim HO. Recent advances in microbial and enzymatic engineering for the biodegradation of micro- and nanoplastics. RSC Adv 2024; 14:9943-9966. [PMID: 38528920 PMCID: PMC10961967 DOI: 10.1039/d4ra00844h] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2024] [Accepted: 03/19/2024] [Indexed: 03/27/2024] Open
Abstract
This review examines the escalating issue of plastic pollution, specifically highlighting the detrimental effects on the environment and human health caused by microplastics and nanoplastics. The extensive use of synthetic polymers such as polyethylene (PE), polyethylene terephthalate (PET), and polystyrene (PS) has raised significant environmental concerns because of their long-lasting and non-degradable characteristics. This review delves into the role of enzymatic and microbial strategies in breaking down these polymers, showcasing recent advancements in the field. The intricacies of enzymatic degradation are thoroughly examined, including the effectiveness of enzymes such as PETase and MHETase, as well as the contribution of microbial pathways in breaking down resilient polymers into more benign substances. The paper also discusses the impact of chemical composition on plastic degradation kinetics and emphasizes the need for an approach to managing the environmental impact of synthetic polymers. The review highlights the significance of comprehending the physical characteristics and long-term impacts of micro- and nanoplastics in different ecosystems. Furthermore, it points out the environmental and health consequences of these contaminants, such as their ability to cause cancer and interfere with the endocrine system. The paper emphasizes the need for advanced analytical methods and effective strategies for enzymatic degradation, as well as continued research and development in this area. This review highlights the crucial role of enzymatic and microbial strategies in addressing plastic pollution and proposes methods to create effective and environmentally friendly solutions.
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Affiliation(s)
- Jaewon Choi
- Division of Chemical Engineering and Bioengineering, College of Art, Culture and Engineering, Kangwon National University Chuncheon Korea
- Department of Smart Health Science and Technology, Kangwon National University Chuncheon Korea
| | - Hongbin Kim
- Division of Chemical Engineering and Bioengineering, College of Art, Culture and Engineering, Kangwon National University Chuncheon Korea
- Department of Smart Health Science and Technology, Kangwon National University Chuncheon Korea
| | - Yu-Rim Ahn
- Division of Chemical Engineering and Bioengineering, College of Art, Culture and Engineering, Kangwon National University Chuncheon Korea
- Department of Smart Health Science and Technology, Kangwon National University Chuncheon Korea
| | - Minse Kim
- Division of Chemical Engineering and Bioengineering, College of Art, Culture and Engineering, Kangwon National University Chuncheon Korea
- Department of Smart Health Science and Technology, Kangwon National University Chuncheon Korea
| | - Seona Yu
- Division of Chemical Engineering and Bioengineering, College of Art, Culture and Engineering, Kangwon National University Chuncheon Korea
- Department of Smart Health Science and Technology, Kangwon National University Chuncheon Korea
| | - Nanhyeon Kim
- Division of Chemical Engineering and Bioengineering, College of Art, Culture and Engineering, Kangwon National University Chuncheon Korea
- Department of Smart Health Science and Technology, Kangwon National University Chuncheon Korea
| | - Su Yeon Lim
- Division of Chemical Engineering and Bioengineering, College of Art, Culture and Engineering, Kangwon National University Chuncheon Korea
- Department of Smart Health Science and Technology, Kangwon National University Chuncheon Korea
| | - Jeong-Ann Park
- Department of Environmental Engineering, Kangwon National University Chuncheon 24341 Republic of Korea
| | - Suk-Jin Ha
- Division of Chemical Engineering and Bioengineering, College of Art, Culture and Engineering, Kangwon National University Chuncheon Korea
- Department of Smart Health Science and Technology, Kangwon National University Chuncheon Korea
| | - Kwang Suk Lim
- Division of Chemical Engineering and Bioengineering, College of Art, Culture and Engineering, Kangwon National University Chuncheon Korea
- Department of Smart Health Science and Technology, Kangwon National University Chuncheon Korea
| | - Hyun-Ouk Kim
- Division of Chemical Engineering and Bioengineering, College of Art, Culture and Engineering, Kangwon National University Chuncheon Korea
- Department of Smart Health Science and Technology, Kangwon National University Chuncheon Korea
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20
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da Silva MRF, Souza KS, Motteran F, de Araújo LCA, Singh R, Bhadouria R, de Oliveira MBM. Exploring biodegradative efficiency: a systematic review on the main microplastic-degrading bacteria. Front Microbiol 2024; 15:1360844. [PMID: 38562477 PMCID: PMC10982435 DOI: 10.3389/fmicb.2024.1360844] [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: 12/24/2023] [Accepted: 02/14/2024] [Indexed: 04/04/2024] Open
Abstract
Introduction Microplastics (MPs) are widely distributed in the environment, causing damage to biota and human health. Due to their physicochemical characteristics, they become resistant particles to environmental degradation, leading to their accumulation in large quantities in the terrestrial ecosystem. Thus, there is an urgent need for measures to mitigate such pollution, with biological degradation being a viable alternative, where bacteria play a crucial role, demonstrating high efficiency in degrading various types of MPs. Therefore, the study aimed to identify bacteria with the potential for MP biodegradation and the enzymes produced during the process. Methods The methodology used followed the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) protocol. Results and Discussion The research yielded 68 eligible studies, highlighting bacteria from the genera Bacillus, Pseudomonas, Stenotrophomonas, and Rhodococcus as the main organisms involved in MP biodegradation. Additionally, enzymes such as hydrolases and alkane hydroxylases were emphasized for their involvement in this process. Thus, the potential of bacterial biodegradation is emphasized as a promising pathway to mitigate the environmental impact of MPs, highlighting the relevance of identifying bacteria with biotechnological potential for large-scale applications in reducing MP pollution.
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Affiliation(s)
| | - Karolayne Silva Souza
- Molecular Biology Laboratory, Department of Biochemistry, Federal University of Pernambuco - UFPE, Recife, PE, Brazil
| | - Fabricio Motteran
- Department of Civil and Environmental Engineering, Federal University of Pernambuco - UFPE, Recife, PE, Brazil
| | | | - Rishikesh Singh
- Amity School of Earth & Environmental Sciences, Amity University Punjab (AUP), Mohali, India
| | - Rahul Bhadouria
- Department of Environmental Studies, Delhi College of Arts and Commerce, University of Delhi, New Delhi, India
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Ali Z, Abdullah M, Yasin MT, Amanat K, Ahmad K, Ahmed I, Qaisrani MM, Khan J. Organic waste-to-bioplastics: Conversion with eco-friendly technologies and approaches for sustainable environment. ENVIRONMENTAL RESEARCH 2024; 244:117949. [PMID: 38109961 DOI: 10.1016/j.envres.2023.117949] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/08/2023] [Revised: 11/24/2023] [Accepted: 12/12/2023] [Indexed: 12/20/2023]
Abstract
Petrochemical-based synthetic plastics poses a threat to humans, wildlife, marine life and the environment. Given the magnitude of eventual depletion of petrochemical sources and global environmental pollution caused by the manufacturing of synthetic plastics such as polyethylene (PET) and polypropylene (PP), it is essential to develop and adopt biopolymers as an environment friendly and cost-effective alternative to synthetic plastics. Research into bioplastics has been gaining traction as a way to create a more sustainable and eco-friendlier environment with a reduced environmental impact. Biodegradable bioplastics can have the same characteristics as traditional plastics while also offering additional benefits due to their low carbon footprint. Therefore, using organic waste from biological origin for bioplastic production not only reduces our reliance on edible feedstock but can also effectively assist with solid waste management. This review aims at providing an in-depth overview on recent developments in bioplastic-producing microorganisms, production procedures from various organic wastes using either pure or mixed microbial cultures (MMCs), microalgae, and chemical extraction methods. Low production yield and production costs are still the major bottlenecks to their deployment at industrial and commercial scale. However, their production and commercialization pose a significant challenge despite such potential. The major constraints are their production in small quantity, poor mechanical strength, lack of facilities and costly feed for industrial-scale production. This review further explores several methods for producing bioplastics with the aim of encouraging researchers and investors to explore ways to utilize these renewable resources in order to commercialize degradable bioplastics. Challenges, future prospects and Life cycle assessment of bioplastics are also highlighted. Utilizing a variety of bioplastics obtained from renewable and cost-effective sources (e.g., organic waste, agro-industrial waste, or microalgae) and determining the pertinent end-of-life option (e.g., composting or anaerobic digestion) may lead towards the right direction that assures the sustainable production of bioplastics.
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Affiliation(s)
- Zain Ali
- Institute of Biological Sciences, Khwaja Fareed University of Engineering & Information Technology, 64200, Rahim Yar Khan, Pakistan
| | - Muhammad Abdullah
- Institute of Biological Sciences, Khwaja Fareed University of Engineering & Information Technology, 64200, Rahim Yar Khan, Pakistan
| | - Muhammad Talha Yasin
- Institute of Biological Sciences, Khwaja Fareed University of Engineering & Information Technology, 64200, Rahim Yar Khan, Pakistan.
| | - Kinza Amanat
- Institute of Biological Sciences, Khwaja Fareed University of Engineering & Information Technology, 64200, Rahim Yar Khan, Pakistan.
| | - Khurshid Ahmad
- State Key Laboratory of Marine Food Processing & Safety Control, College of Food Science and Engineering, Ocean University of China, No.1299, Sansha Road, Qingdao, Shandong Province, 266404, P.R. China.
| | - Ishfaq Ahmed
- Haide College, Ocean University of China, Laoshan Campus, Qingdao, Shandong Province, 266100, PR China
| | - Muther Mansoor Qaisrani
- Institute of Biological Sciences, Khwaja Fareed University of Engineering & Information Technology, 64200, Rahim Yar Khan, Pakistan
| | - Jallat Khan
- Institute of Biological Sciences, Khwaja Fareed University of Engineering & Information Technology, 64200, Rahim Yar Khan, Pakistan; Institute of Chemistry, Khwaja Fareed University of Engineering and Information Technology (KFUEIT), 64200, Rahim Yar Khan, Pakistan.
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22
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Parida D, Katare K, Ganguly A, Chakraborty D, Konar O, Nogueira R, Bala K. Molecular docking and metagenomics assisted mitigation of microplastic pollution. CHEMOSPHERE 2024; 351:141271. [PMID: 38262490 DOI: 10.1016/j.chemosphere.2024.141271] [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: 09/29/2023] [Revised: 01/18/2024] [Accepted: 01/19/2024] [Indexed: 01/25/2024]
Abstract
Microplastics, tiny, flimsy, and direct progenitors of principal and subsidiary plastics, cause environmental degradation in aquatic and terrestrial entities. Contamination concerns include irrevocable impacts, potential cytotoxicity, and negative health effects on mortals. The detection, recovery, and degradation strategies of these pollutants in various biota and ecosystems, as well as their impact on plants, animals, and humans, have been a topic of significant interest. But the natural environment is infested with several types of plastics, all having different chemical makeup, structure, shape, and origin. Plastic trash acts as a substrate for microbial growth, creating biofilms on the plastisphere surface. This colonizing microbial diversity can be glimpsed with meta-genomics, a culture-independent approach. Owing to its comprehensive description of microbial communities, genealogical evidence on unconventional biocatalysts or enzymes, genomic correlations, evolutionary profile, and function, it is being touted as one of the promising tools in identifying novel enzymes for the degradation of polymers. Additionally, computational tools such as molecular docking can predict the binding of these novel enzymes to the polymer substrate, which can be validated through in vitro conditions for its environmentally feasible applications. This review mainly deals with the exploration of metagenomics along with computational tools to provide a clearer perspective into the microbial potential in the biodegradation of microplastics. The computational tools due to their polymathic nature will be quintessential in identifying the enzyme structure, binding affinities of the prospective enzymes to the substrates, and foretelling of degradation pathways involved which can be quite instrumental in the furtherance of the plastic degradation studies.
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Affiliation(s)
- Dinesh Parida
- Department of Biosciences and Biomedical Engineering, Indian Institute of Technology, Indore, 453552, India.
| | - Konica Katare
- Department of Biosciences and Biomedical Engineering, Indian Institute of Technology, Indore, 453552, India.
| | - Atmaadeep Ganguly
- Department of Microbiology, Ramakrishna Mission Vivekananda Centenary College, West Bengal State University, Kolkata, 700118, India.
| | - Disha Chakraborty
- Department of Botany, Shri Shikshayatan College, University of Calcutta, Lord Sinha Road, Kolkata, 700071, India.
| | - Oisi Konar
- Department of Botany, Shri Shikshayatan College, University of Calcutta, Lord Sinha Road, Kolkata, 700071, India.
| | - Regina Nogueira
- Institute of Sanitary Engineering and Waste Management, Leibniz Universität, Hannover, Germany.
| | - Kiran Bala
- Department of Biosciences and Biomedical Engineering, Indian Institute of Technology, Indore, 453552, India.
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23
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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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24
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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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25
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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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26
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Han W, Zhang J, Chen Q, Xie Y, Zhang M, Qu J, Tan Y, Diao Y, Wang Y, Zhang Y. Biodegradation of poly(ethylene terephthalate) through PETase surface-display: From function to structure. JOURNAL OF HAZARDOUS MATERIALS 2024; 461:132632. [PMID: 37804764 DOI: 10.1016/j.jhazmat.2023.132632] [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: 07/19/2023] [Revised: 09/20/2023] [Accepted: 09/24/2023] [Indexed: 10/09/2023]
Abstract
Polyethylene terephthalate (PET) is one of the most used plastics which has caused some environmental pollution and social problems. Although many newly discovered or modified PET hydrolases have been reported at present, there is still a lack of comparison between their hydrolytic capacities, as well as the need for new biotechnology to apply them for the PET treatment. Here, we systematically studied the surface-display technology for PET hydrolysis using several PET hydrolases. It is found that anchoring protein types had little influence on the surface-display result under T7 promoter, while the PET hydrolase types were more important. By contrast, the newly reported FAST-PETase showed the strongest hydrolysis effect, achieving 71.3% PET hydrolysis in 24 h by pGSA-FAST-PETase. Via model calculation, FAST-PETase indeed exhibited higher temperature tolerance and catalytic capacity. Besides, smaller particle size and lower crystallinity favored the hydrolysis of PET pellets. Through protein structure comparison, we summarized the common characteristics of efficient PET-hydrolyzing enzymes and proposed three main crystal structures of PET enzymes via crystal structural analysis, with ISPETase being the representative and main structure. Surface co-display of FAST-PETase and MHETase can promote the hydrolysis of PET, and the C-terminal of the fusion protein is crucial for PET hydrolysis. The results of our research can be helpful for PET contamination removal as well as other areas involving the application of enzymes. SYNOPSIS: This research can promote the development of better PET hydrolase and its applications in PET pollution treatment via bacteria surface-display.
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Affiliation(s)
- Wei Han
- School of Resources and Environment, Northeast Agricultural University, Heilongjiang 150030, PR China
| | - Jun Zhang
- School of Resources and Environment, Northeast Agricultural University, Heilongjiang 150030, PR China
| | - Qi Chen
- School of Resources and Environment, Northeast Agricultural University, Heilongjiang 150030, PR China
| | - Yuzhu Xie
- School of Resources and Environment, Northeast Agricultural University, Heilongjiang 150030, PR China
| | - Meng Zhang
- School of Resources and Environment, Northeast Agricultural University, Heilongjiang 150030, PR China
| | - Jianhua Qu
- School of Resources and Environment, Northeast Agricultural University, Heilongjiang 150030, PR China
| | - Yuanji Tan
- School of Resources and Environment, Northeast Agricultural University, Heilongjiang 150030, PR China
| | - Yiran Diao
- School of Resources and Environment, Northeast Agricultural University, Heilongjiang 150030, PR China
| | - Yixuan Wang
- School of Resources and Environment, Northeast Agricultural University, Heilongjiang 150030, PR China
| | - Ying Zhang
- School of Resources and Environment, Northeast Agricultural University, Heilongjiang 150030, PR China.
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27
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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: 0] [Impact Index Per Article: 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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28
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Qiu J, Chen Y, Zhang L, Wu J, Zeng X, Shi X, Liu L, Chen J. A comprehensive review on enzymatic biodegradation of polyethylene terephthalate. ENVIRONMENTAL RESEARCH 2024; 240:117427. [PMID: 37865324 DOI: 10.1016/j.envres.2023.117427] [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: 08/28/2023] [Revised: 10/11/2023] [Accepted: 10/15/2023] [Indexed: 10/23/2023]
Abstract
Polyethylene terephthalate (PET) is a polymer synthesized via the dehydration and condensation reaction between ethylene glycol and terephthalic acid. PET has emerged as one of the most extensively employed plastic materials due to its exceptional plasticity and durability. Nevertheless, PET has a complex structure and is extremely difficult to degrade in nature, causing severe pollution to the global ecological environment and posing a threat to human health. Currently, the methods for PET processing mainly include physical, chemical, and biological methods. Biological enzyme degradation is considered the most promising PET degradation method. In recent years, an increasing number of enzymes that can degrade PET have been identified, and they primarily target the ester bond of PET. This review comprehensively introduced the latest research progress in PET enzymatic degradation from the aspects of PET-degrading enzymes, PET biodegradation pathways, the catalytic mechanism of PET-degrading enzymes, and biotechnological strategies for enhancing PET-degrading enzymes. On this basis, the current challenges within the enzymatic PET degradation process were summarized, and the directions that need to be worked on in the future were pointed out. This review provides a reference and basis for the subsequent effective research on PET biodegradation.
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Affiliation(s)
- Jiarong Qiu
- School of Advanced Manufacturing, Fuzhou University, Jinjiang 362251, China; Development Center of Science and Education Park of Fuzhou University, Jinjiang, 362251, China
| | - Yuxin Chen
- School of Advanced Manufacturing, Fuzhou University, Jinjiang 362251, China
| | - Liangqing Zhang
- School of Advanced Manufacturing, Fuzhou University, Jinjiang 362251, China; Development Center of Science and Education Park of Fuzhou University, Jinjiang, 362251, China.
| | - Jinzhi Wu
- School of Advanced Manufacturing, Fuzhou University, Jinjiang 362251, China
| | - Xianhai Zeng
- College of Energy, Xiamen University, Xiamen 361102, China
| | - Xinguo Shi
- School of Advanced Manufacturing, Fuzhou University, Jinjiang 362251, China
| | - Lemian Liu
- School of Advanced Manufacturing, Fuzhou University, Jinjiang 362251, China
| | - Jianfeng Chen
- School of Advanced Manufacturing, Fuzhou University, Jinjiang 362251, China
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29
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Buhari SB, Nezhad NG, Normi YM, Shariff FM, Leow TC. Insight on recently discovered PET polyester-degrading enzymes, thermostability and activity analyses. 3 Biotech 2024; 14:31. [PMID: 38178895 PMCID: PMC10761646 DOI: 10.1007/s13205-023-03882-8] [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: 07/04/2023] [Accepted: 12/05/2023] [Indexed: 01/06/2024] Open
Abstract
The flexibility and the low production costs offered by plastics have made them crucial to society. Unfortunately, due to their resistance to biological degradation, plastics remain in the environment for an extended period of time, posing a growing risk to life on earth. Synthetic treatments of plastic waste damage the environment and may cause damage to human health. Bacterial and fungal isolates have been reported to degrade plastic polymers in a logistic safe approach with the help of their microbial cell enzymes. Recently, the bacterial strain Ideonella sakaiensis (201-F6) was discovered to break down and assimilate polyethylene terephthalate (PET) plastic via metabolic processes at 30 °C to 37 °C. PETase and MHETase enzymes help the bacterium to accomplish such tremendous action at lower temperatures than previously discovered enzymes. In addition to functioning at low temperatures, the noble bacterium's enzymes have amazing qualities over pH and PET plastic degradation, including a shorter period of degradation. It has been proven that using the enzyme PETase, this bacterium hydrolyzes the ester linkages of PET plastic, resulting in production of terephthalic acid (TPA), nontoxic compound and mono-2-hydroxyethyl (MHET), along with further depolymerization of MHET to release ethylene glycogen (EG) and terephthalic acid (TPA) by the second enzyme MHETase. Enzymatic plastic degradation has been proposed as an environmentally friendly and long-term solution to plastic waste in the environment. As a result, this review focuses on the enzymes involved in hydrolyzing PET plastic polymers, as well as some of the other microorganisms involved in plastic degradation.
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Affiliation(s)
- Sunusi Bataiya Buhari
- Enzyme and Microbial Research Center, Faculty of Biotechnology and Biomolecular Sciences, Universiti Putra Malaysia, 43400 UPM Serdang, Selangor Malaysia
- Department of Cell and Molecular Biology, Faculty of Biotechnology and Biomolecular Sciences, Universiti Putra Malaysia, 43400 UPM Serdang, Selangor Malaysia
| | - Nima Ghahremani Nezhad
- Enzyme and Microbial Research Center, Faculty of Biotechnology and Biomolecular Sciences, Universiti Putra Malaysia, 43400 UPM Serdang, Selangor Malaysia
- Department of Cell and Molecular Biology, Faculty of Biotechnology and Biomolecular Sciences, Universiti Putra Malaysia, 43400 UPM Serdang, Selangor Malaysia
| | - Yahaya M. Normi
- Enzyme and Microbial Research Center, Faculty of Biotechnology and Biomolecular Sciences, Universiti Putra Malaysia, 43400 UPM Serdang, Selangor Malaysia
- Department of Cell and Molecular Biology, Faculty of Biotechnology and Biomolecular Sciences, Universiti Putra Malaysia, 43400 UPM Serdang, Selangor Malaysia
| | - Fairolniza Mohd Shariff
- Enzyme and Microbial Research Center, Faculty of Biotechnology and Biomolecular Sciences, Universiti Putra Malaysia, 43400 UPM Serdang, Selangor Malaysia
- Department of Microbiology, Faculty of Biotechnology and Biomolecular Sciences, Universiti Putra Malaysia, 43400 UPM Serdang, Selangor Malaysia
| | - Thean Chor Leow
- Enzyme and Microbial Research Center, Faculty of Biotechnology and Biomolecular Sciences, Universiti Putra Malaysia, 43400 UPM Serdang, Selangor Malaysia
- Department of Cell and Molecular Biology, Faculty of Biotechnology and Biomolecular Sciences, Universiti Putra Malaysia, 43400 UPM Serdang, Selangor Malaysia
- Institute of Bioscience, Universiti Putra Malaysia, 43400 UPM Serdang, Selangor Malaysia
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30
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Lo LSH, Liu X, Qian PY, Häggblom MM, Cheng J. Microbial colonization and chemically influenced selective enrichment of bacterial pathogens on polycarbonate plastic. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2024; 31:8061-8071. [PMID: 38175506 DOI: 10.1007/s11356-023-31752-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/28/2023] [Accepted: 12/23/2023] [Indexed: 01/05/2024]
Abstract
Plastic pollution in aquatic environments poses significant concerns due to its potential to serve as a refuge for aquatic pathogens. However, the role of plastic surfaces and microbial biofilm interfaces in facilitating pathogen development remains poorly understood. In this study, a microcosm setup was employed to investigate the interactions between plastics and the microbial community and examine the differences in bacterial community composition and potential pathogen occurrences between the plastisphere-biofilm and surrounding seawater. Community composition analysis combined with SEM observations over time indicated that biofilm extracellular polymeric substance formation over 14 days had a link with the relative abundance and succession patterns of pathogen taxa. Colony clusters were observed on biofilms from day 7 and coincided with higher bacterial pathogen dominance. On day 14, pathogen abundance overall decreased with a potentially degrading biofilm. Pseudomonas and Pseudoalteromonas were the dominant potential pathogen groups observed in the microcosm. When further subjected to chemical treatment as an imposed environmental stress over time, biofilm-associated Psuedoalteromonas sharply increased in abundance after three days of exposure, but quickly diminished by 14 days in favor of genera such as Acinetobacter, Pseudomonas, and Staphylococcus. These results suggest that environmental plastisphere-biofilms can promote the early selection, enrichment, and spread of pathogenic bacteria in the aquatic environment and could be later worsened under chemical and long-term pressure. This study provided new insights into the succession of pathogens in plastisphere biofilms, contributing to the understanding of pathogen risks involved in emerging plastisphere biofilms in light of global plastic pollution.
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Affiliation(s)
- Linus Shing Him Lo
- Department of Science and Environmental Studies and State Key Laboratory of Marine Pollution, The Education University of Hong Kong, New Territories, Hong Kong, China
- The Southern Marine Science and Engineering Guangdong Laboratory (Guangzhou), Guangzhou, 511458, China
| | - Xuan Liu
- The Southern Marine Science and Engineering Guangdong Laboratory (Guangzhou), Guangzhou, 511458, China
- Department of Ocean Science and Hong Kong Branch of the Southern Marine Science and Engineering Guangdong Laboratory (Guangzhou), Hong Kong University of Science and Technology, Kowloon, Hong Kong, China
| | - Pei-Yuan Qian
- The Southern Marine Science and Engineering Guangdong Laboratory (Guangzhou), Guangzhou, 511458, China
- Department of Ocean Science and Hong Kong Branch of the Southern Marine Science and Engineering Guangdong Laboratory (Guangzhou), Hong Kong University of Science and Technology, Kowloon, Hong Kong, China
| | - Max M Häggblom
- Department of Biochemistry and Microbiology, School of Environmental and Biological Sciences, Rutgers, The State University of New Jersey, 76 Lipman Drive, New Brunswick, NJ, 08901-8525, USA
| | - Jinping Cheng
- Department of Science and Environmental Studies and State Key Laboratory of Marine Pollution, The Education University of Hong Kong, New Territories, Hong Kong, China.
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31
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de Witt J, Molitor R, Gätgens J, Ortmann de Percin Northumberland C, Kruse L, Polen T, Wynands B, van Goethem K, Thies S, Jaeger K, Wierckx N. Biodegradation of poly(ester-urethane) coatings by Halopseudomonas formosensis. Microb Biotechnol 2024; 17:e14362. [PMID: 37991424 PMCID: PMC10834883 DOI: 10.1111/1751-7915.14362] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2023] [Revised: 09/18/2023] [Accepted: 10/12/2023] [Indexed: 11/23/2023] Open
Abstract
Impranil® DLN-SD is a poly(ester-urethane) (PEU) that is widely used as coating material for textiles to fine-tune and improve their properties. Since coatings increase the complexity of such plastic materials, they can pose a hindrance for sustainable end-of-life solutions of plastics using enzymes or microorganisms. In this study, we isolated Halopseudomonas formosensis FZJ due to its ability to grow on Impranil DLN-SD and other PEUs as sole carbon sources. The isolated strain was exceptionally thermotolerant as it could degrade Impranil DLN-SD at up to 50°C. We identified several putative extracellular hydrolases of which the polyester hydrolase Hfor_PE-H showed substrate degradation of Impranil DLN-SD and thus was purified and characterized in detail. Hfor_PE-H showed moderate temperature stability (Tm = 53.9°C) and exhibited activity towards Impranil DLN-SD as well as polyethylene terephthalate. Moreover, we revealed the enzymatic release of monomers from Impranil DLN-SD by Hfor_PE-H using GC-ToF-MS and could decipher the associated metabolic pathways in H. formosensis FZJ. Overall, this study provides detailed insights into the microbial and enzymatic degradation of PEU coatings, thereby deepening our understanding of microbial coating degradation in both contained and natural environments. Moreover, the study highlights the relevance of the genus Halopseudomonas and especially the novel isolate and its enzymes for future bio-upcycling processes of coated plastic materials.
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Affiliation(s)
- Jan de Witt
- Institute of Bio‐ and Geosciences IBG‐1: Biotechnology, Forschungszentrum JülichJülichGermany
| | - Rebecka Molitor
- Institute of Molecular Enzyme Technology, Heinrich‐Heine‐University DüsseldorfForschungszentrum JülichJülichGermany
| | - Jochem Gätgens
- Institute of Bio‐ and Geosciences IBG‐1: Biotechnology, Forschungszentrum JülichJülichGermany
| | | | - Luzie Kruse
- Institute of Molecular Enzyme Technology, Heinrich‐Heine‐University DüsseldorfForschungszentrum JülichJülichGermany
| | - Tino Polen
- Institute of Bio‐ and Geosciences IBG‐1: Biotechnology, Forschungszentrum JülichJülichGermany
| | - Benedikt Wynands
- Institute of Bio‐ and Geosciences IBG‐1: Biotechnology, Forschungszentrum JülichJülichGermany
| | | | - Stephan Thies
- Institute of Molecular Enzyme Technology, Heinrich‐Heine‐University DüsseldorfForschungszentrum JülichJülichGermany
| | - Karl‐Erich Jaeger
- Institute of Bio‐ and Geosciences IBG‐1: Biotechnology, Forschungszentrum JülichJülichGermany
- Institute of Molecular Enzyme Technology, Heinrich‐Heine‐University DüsseldorfForschungszentrum JülichJülichGermany
| | - Nick Wierckx
- Institute of Bio‐ and Geosciences IBG‐1: Biotechnology, Forschungszentrum JülichJülichGermany
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Zhang H, Dierkes RF, Perez-Garcia P, Costanzi E, Dittrich J, Cea PA, Gurschke M, Applegate V, Partus K, Schmeisser C, Pfleger C, Gohlke H, Smits SHJ, Chow J, Streit WR. The metagenome-derived esterase PET40 is highly promiscuous and hydrolyses polyethylene terephthalate (PET). FEBS J 2024; 291:70-91. [PMID: 37549040 DOI: 10.1111/febs.16924] [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: 01/31/2023] [Revised: 07/24/2023] [Accepted: 08/07/2023] [Indexed: 08/09/2023]
Abstract
Polyethylene terephthalate (PET) is a widely used synthetic polymer and known to contaminate marine and terrestrial ecosystems. Only few PET-active microorganisms and enzymes (PETases) are currently known, and it is debated whether degradation activity for PET originates from promiscuous enzymes with broad substrate spectra that primarily act on natural polymers or other bulky substrates, or whether microorganisms evolved their genetic makeup to accepting PET as a carbon source. Here, we present a predicted diene lactone hydrolase designated PET40, which acts on a broad spectrum of substrates, including PET. It is the first esterase with activity on PET from a GC-rich Gram-positive Amycolatopsis species belonging to the Pseudonocardiaceae (Actinobacteria). It is highly conserved within the genera Amycolatopsis and Streptomyces. PET40 was identified by sequence-based metagenome search using a PETase-specific hidden Markov model. Besides acting on PET, PET40 has a versatile substrate spectrum, hydrolyzing δ-lactones, β-lactam antibiotics, the polyester-polyurethane Impranil® DLN, and various para-nitrophenyl ester substrates. Molecular docking suggests that the PET degradative activity is likely a result of the promiscuity of PET40, as potential binding modes were found for substrates encompassing mono(2-hydroxyethyl) terephthalate, bis(2-hydroxyethyl) terephthalate, and a PET trimer. We also solved the crystal structure of the inactive PET40 variant S178A to 1.60 Å resolution. PET40 is active throughout a wide pH (pH 4-10) and temperature range (4-65 °C) and remarkably stable in the presence of 5% SDS, making it a promising enzyme as a starting point for further investigations and optimization approaches.
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Affiliation(s)
- Hongli Zhang
- Department of Microbiology and Biotechnology, University of Hamburg, Germany
| | - Robert F Dierkes
- Department of Microbiology and Biotechnology, University of Hamburg, Germany
| | - Pablo Perez-Garcia
- Department of Microbiology and Biotechnology, University of Hamburg, Germany
- Molecular Microbiology, Institute for General Microbiology, Kiel University, Germany
| | - Elisa Costanzi
- Center for Structural Studies, Heinrich Heine University, Düsseldorf, Germany
| | - Jonas Dittrich
- Institute for Pharmaceutical and Medicinal Chemistry, Heinrich Heine University, Düsseldorf, Germany
| | - Pablo A Cea
- Institute for Pharmaceutical and Medicinal Chemistry, Heinrich Heine University, Düsseldorf, Germany
| | - Marno Gurschke
- Department of Microbiology and Biotechnology, University of Hamburg, Germany
| | - Violetta Applegate
- Center for Structural Studies, Heinrich Heine University, Düsseldorf, Germany
| | - Kristina Partus
- Department of Microbiology and Biotechnology, University of Hamburg, Germany
| | - Christel Schmeisser
- Department of Microbiology and Biotechnology, University of Hamburg, Germany
| | - Christopher Pfleger
- Institute for Pharmaceutical and Medicinal Chemistry, Heinrich Heine University, Düsseldorf, Germany
| | - Holger Gohlke
- Institute for Pharmaceutical and Medicinal Chemistry, Heinrich Heine University, Düsseldorf, Germany
- Institute of Bio- and Geosciences (IBG-4: Bioinformatics), John von Neumann Institute for Computing and Jülich Supercomputing Centre, Forschungszentrum Jülich GmbH, Germany
| | - Sander H J Smits
- Center for Structural Studies, Heinrich Heine University, Düsseldorf, Germany
- Institute of Biochemistry, Heinrich Heine University, Düsseldorf, Germany
| | - Jennifer Chow
- Department of Microbiology and Biotechnology, University of Hamburg, Germany
| | - Wolfgang R Streit
- Department of Microbiology and Biotechnology, University of Hamburg, Germany
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33
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Kruse L, Loeschcke A, de Witt J, Wierckx N, Jaeger K, Thies S. Halopseudomonas species: Cultivation and molecular genetic tools. Microb Biotechnol 2024; 17:e14369. [PMID: 37991430 PMCID: PMC10832565 DOI: 10.1111/1751-7915.14369] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2023] [Revised: 10/24/2023] [Accepted: 10/26/2023] [Indexed: 11/23/2023] Open
Abstract
The Halopseudomonas species, formerly classified as Pseudomonas pertucinogena lineage, form a unique phylogenetic branch within the Pseudomonads. Most strains have recently been isolated from challenging habitats including oil- or metal-polluted sites, deep sea, and intertidal zones, suggesting innate resilience to physical and chemical stresses. Despite their comparably small genomes, these bacteria synthesise several biomolecules with biotechnological potential and a role in the degradation of anthropogenic pollutants has been suggested for some Halopseudomonads. Until now, these bacteria are not readily amenable to existing cultivation and cloning methods. We addressed these limitations by selecting four Halopseudomonas strains of particular interest, namely H. aestusnigri, H. bauzanensis, H. litoralis, and H. oceani to establish microbiological and molecular genetic methods. We found that C4 -C10 dicarboxylic acids serve as viable carbon sources in both complex and mineral salt cultivation media. We also developed plasmid DNA transfer protocols and assessed vectors with different origins of replication and promoters inducible with isopropyl-β-d-thiogalactopyranoside, l-arabinose, and salicylate. Furthermore, we have demonstrated the simultaneous genomic integration of expression cassettes into one and two attTn7 integration sites. Our results provide a valuable toolbox for constructing robust chassis strains and highlight the biotechnological potential of Halopseudomonas strains.
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Affiliation(s)
- Luzie Kruse
- Institute of Molecular Enzyme TechnologyHeinrich Heine UniversityDüsseldorfGermany
| | - Anita Loeschcke
- Institute of Molecular Enzyme TechnologyHeinrich Heine UniversityDüsseldorfGermany
| | - Jan de Witt
- Institute of Bio‐ and Geosciences IBG‐1: BiotechnologyJülichGermany
| | - Nick Wierckx
- Institute of Bio‐ and Geosciences IBG‐1: BiotechnologyJülichGermany
| | - Karl‐Erich Jaeger
- Institute of Molecular Enzyme TechnologyHeinrich Heine UniversityDüsseldorfGermany
- Institute of Bio‐ and Geosciences IBG‐1: BiotechnologyJülichGermany
| | - Stephan Thies
- Institute of Molecular Enzyme TechnologyHeinrich Heine UniversityDüsseldorfGermany
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Talukdar A, Kundu P, Bhattacharjee S, Dey S, Dey A, Biswas JK, Chaudhuri P, Bhattacharya S. Microplastics in mangroves with special reference to Asia: Occurrence, distribution, bioaccumulation and remediation options. THE SCIENCE OF THE TOTAL ENVIRONMENT 2023; 904:166165. [PMID: 37574065 DOI: 10.1016/j.scitotenv.2023.166165] [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: 05/01/2023] [Revised: 07/15/2023] [Accepted: 08/07/2023] [Indexed: 08/15/2023]
Abstract
Microplastics (MPs) are a new and lesser-known pollutant that has intrigued the interest of scientists all over the world in recent decades. MP (<5mm in size) can enter marine environments such as mangrove forests in a variety of ways, interfering with the health of the environment and organisms. Mangroves are now getting increasingly exposed to microplastic contamination due to their proximity to human activities and their position as critical transitional zones between land and sea. The present study reviews the status of MPs contamination specifically in mangrove ecosystems situated in Asia. Different sources and characteristics of MPs, subsequent deposition of MPs in mangrove water and sediments, bioaccumulation in different organisms are discussed in this context. MP concentrations in sediments and organisms were higher in mangrove forests exposed to fishing, coastal tourism, urban, and industrial wastewater than in pristine areas. The distribution of MPs varies from organism to organism in mangrove ecosystems, and is significantly influenced by their morphometric characteristics, feeding habits, dwelling environment etc. Mangrove plants can accumulate microplastics in their roots, stem and leaves through absorption, adsorption and entrapment helping in reducing abundance of microplastic in the surrounding environment. Several bacterial and fungal species are reported from these mangrove ecosystems, which are capable of degrading MPs. The bioremediation potential of mangrove plants offers an innovative and sustainable approach to mitigate microplastic pollution. Diverse mechanisms of MP biodegradation by mangrove dwelling organisms are discussed in this context. Biotechnological applications can be utilized to explore the genetic potential of the floral and faunal species found in the Asian mangroves. Detailed studies are required to monitor, control, and evaluate MP pollution in sediments and various organisms in mangrove ecosystems in Asia as well as in other parts of the world.
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Affiliation(s)
| | - Pritha Kundu
- School of Ecology and Environment Studies, Nalanda University, Rajgir, Nalanda, Bihar 803116, India
| | - Shrayan Bhattacharjee
- Ecosystem and Ecology Laboratory, Post-graduate Department of Zoology, Ramakrishna Mission Vivekananda Centenary College, Rahara, Kolkata 700118, India
| | - Satarupa Dey
- Department of Botany, Shyampur Siddheswari Mahavidyalaya, Howrah 711301, West Bengal, India
| | - Abhijit Dey
- Department of Life Sciences, Presidency University, 86/1 College Street, Kolkata 700073, West Bengal, India
| | - Jayanta Kumar Biswas
- Enviromicrobiology, Ecotoxicology & Ecotechnology Research Laboratory (3E-MicroToxTech Lab), Department of Ecological Studies, and International Centre for Ecological Engineering, University of Kalyani, Nadia, West Bengal 741235, India
| | - Punarbasu Chaudhuri
- Department of Environmental Science, University of Calcutta, Kolkata 700019, West Bengal, India
| | - Sayan Bhattacharya
- School of Ecology and Environment Studies, Nalanda University, Rajgir, Nalanda, Bihar 803116, India.
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35
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Degli-Innocenti F, Breton T, Chinaglia S, Esposito E, Pecchiari M, Pennacchio A, Pischedda A, Tosin M. Microorganisms that produce enzymes active on biodegradable polyesters are ubiquitous. Biodegradation 2023; 34:489-518. [PMID: 37354274 DOI: 10.1007/s10532-023-10031-8] [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: 01/20/2023] [Accepted: 05/30/2023] [Indexed: 06/26/2023]
Abstract
Biodegradability standards measure ultimate biodegradation of polymers by exposing the material under test to a natural microbial inoculum. Available tests developed by the International Organization for Standardization (ISO) use inoculums sampled from different environments e.g. soil, marine sediments, seawater. Understanding whether each inoculum is to be considered as microbially unique or not can be relevant for the interpretation of tests results. In this review, we address this question by consideration of the following: (i) the chemical nature of biodegradable plastics (virtually all biodegradable plastics are polyesters) (ii) the diffusion of ester bonds in nature both in simple molecules and in polymers (ubiquitous); (iii) the diffusion of decomposers capable of producing enzymes, called esterases, which accelerate the hydrolysis of esters, including polyesters (ubiquitous); (iv) the evidence showing that synthetic polyesters can be depolymerized by esterases (large and growing); (v) the evidence showing that these esterases are ubiquitous (growing and confirmed by bioinformatics studies). By combining the relevant available facts it can be concluded that if a certain polyester shows ultimate biodegradation when exposed to a natural inoculum, it can be considered biodegradable and need not be retested using other inoculums. Obviously, if the polymer does not show ultimate biodegradation it must be considered recalcitrant, until proven otherwise.
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Affiliation(s)
| | - Tony Breton
- Novamont S.p.A., via Fauser 8, 28100, Novara, Italy
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36
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Howard SA, Carr CM, Sbahtu HI, Onwukwe U, López MJ, Dobson ADW, McCarthy RR. Enrichment of native plastic-associated biofilm communities to enhance polyester degrading activity. Environ Microbiol 2023; 25:2698-2718. [PMID: 37515381 PMCID: PMC10947123 DOI: 10.1111/1462-2920.16466] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2022] [Accepted: 06/30/2023] [Indexed: 07/30/2023]
Abstract
Plastic pollution is an increasing worldwide problem urgently requiring a solution. While recycling rates are increasing globally, only 9% of all plastic waste has been recycled, and with the cost and limited downstream uses of recycled plastic, an alternative is needed. Here, we found that expanded polystyrene (EPS) promoted high levels of bacterial biofilm formation and sought out environmental EPS waste to characterize these native communities. We demonstrated that the EPS attached communities had limited plastic degrading activity. We then performed a long-term enrichment experiment where we placed a robust selection pressure on these communities by limiting carbon availability such that the waste plastic was the only carbon source. Seven of the resulting enriched bacterial communities had increased plastic degrading activity compared to the starting bacterial communities. Pseudomonas stutzeri was predominantly identified in six of the seven enriched communities as the strongest polyester degrader. Sequencing of one isolate of P. stutzeri revealed two putative polyesterases and one putative MHETase. This indicates that waste plastic-associated biofilms are a source for bacteria that have plastic-degrading potential, and that this potential can be unlocked through selective pressure and further in vitro enrichment experiments, resulting in biodegradative communities that are better than nature.
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Affiliation(s)
- Sophie A. Howard
- Centre for Inflammation Research and Translational Medicine, Division of Biosciences, Department of Life Sciences, College of Health and Life SciencesBrunel University LondonUxbridgeUK
| | - Clodagh M. Carr
- School of MicrobiologyUniversity College CorkCorkIreland
- SSPC‐SFI Research Centre for PharmaceuticalsUniversity College CorkCorkIreland
| | - Habteab Isaack Sbahtu
- Centre for Inflammation Research and Translational Medicine, Division of Biosciences, Department of Life Sciences, College of Health and Life SciencesBrunel University LondonUxbridgeUK
| | - Uchechukwu Onwukwe
- Experimental Techniques Centre, College of Engineering, Design and Physical SciencesBrunel University LondonUxbridgeUK
| | - Maria J. López
- Department of Biology and Geology, CITE II‐BUniversity of Almería, Agrifood Campus of International Excellence ceiA3, CIAIMBITALAlmeriaSpain
| | - Alan D. W. Dobson
- School of MicrobiologyUniversity College CorkCorkIreland
- SSPC‐SFI Research Centre for PharmaceuticalsUniversity College CorkCorkIreland
| | - Ronan R. McCarthy
- Centre for Inflammation Research and Translational Medicine, Division of Biosciences, Department of Life Sciences, College of Health and Life SciencesBrunel University LondonUxbridgeUK
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37
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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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38
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Zeng C, Ding F, Zhou J, Dong W, Cui Z, Yan X. Biodegradation of Poly(ethylene terephthalate) by Bacillus safensis YX8. Int J Mol Sci 2023; 24:16434. [PMID: 38003625 PMCID: PMC10671283 DOI: 10.3390/ijms242216434] [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: 10/17/2023] [Revised: 11/06/2023] [Accepted: 11/15/2023] [Indexed: 11/26/2023] Open
Abstract
Due to the extensive utilization of poly (ethylene terephthalate) (PET), a significant amount of PET waste has been discharged into the environment, endangering both human health and the ecology. As an eco-friendly approach to PET waste treatment, biodegradation is dependent on efficient strains and enzymes. In this study, a screening method was first established using polycaprolactone (PCL) and PET nanoparticles as substrates. A PET-degrading strain YX8 was isolated from the surface of PET waste. Based on the phylogenetic analysis of 16S rRNA and gyrA genes, this strain was identified as Bacillus safensis. Strain YX8 demonstrated the capability to degrade PET nanoparticles, resulting in the production of terephthalic acid (TPA), mono (2-hydroxyethyl) terephthalic acid (MHET), and bis (2-hydroxyethyl) terephthalic acid (BHET). Erosion spots on the PET film were observed after incubation with strain YX8. Furthermore, the extracellular enzymes produced by strain YX8 exhibited the ability to form a clear zone on the PCL plate and to hydrolyze PET nanoparticles to generate TPA, MHET, and BHET. This work developed a method for the isolation of PET-degrading microorganisms and provides new strain resources for PET degradation and for the mining of functional enzymes.
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Affiliation(s)
- Caiting Zeng
- College of Life Sciences, Nanjing Agricultural University, Nanjing 210095, China; (C.Z.); (F.D.); (Z.C.)
| | - Fanghui Ding
- College of Life Sciences, Nanjing Agricultural University, Nanjing 210095, China; (C.Z.); (F.D.); (Z.C.)
| | - Jie Zhou
- College of Biotechnology and Pharmaceutical Engineering, Nanjing Tech University, Nanjing 211816, China; (J.Z.); (W.D.)
| | - Weiliang Dong
- College of Biotechnology and Pharmaceutical Engineering, Nanjing Tech University, Nanjing 211816, China; (J.Z.); (W.D.)
| | - Zhongli Cui
- College of Life Sciences, Nanjing Agricultural University, Nanjing 210095, China; (C.Z.); (F.D.); (Z.C.)
| | - Xin Yan
- College of Life Sciences, Nanjing Agricultural University, Nanjing 210095, China; (C.Z.); (F.D.); (Z.C.)
- Jiangsu Provincial Key Laboratory for Organic Solid Waste Utilization, Nanjing Agricultural University, Nanjing 210095, China
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39
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Guo W, Duan J, Shi Z, Yu X, Shao Z. Biodegradation of PET by the membrane-anchored PET esterase from the marine bacterium Rhodococcus pyridinivorans P23. Commun Biol 2023; 6:1090. [PMID: 37891241 PMCID: PMC10611731 DOI: 10.1038/s42003-023-05470-1] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2023] [Accepted: 10/16/2023] [Indexed: 10/29/2023] Open
Abstract
Evidence for microbial biodegradation of polyethylene terephthalate (PET) has been reported, but little is known about the PET biodegradation process and molecular mechanism by marine microorganisms. Here, we show the biodegradation of PET by the membrane-anchored PET esterase from the marine bacterium Rhodococcus pyridinivorans P23, elucidate the properties of this enzyme, and propose the PET biodegradation by this strain in biofilm. We identify the PET-degrading enzyme dubbed PET esterase through activity tracking. In addition to depolymerizing PET, it hydrolyzes MHET into TPA under acid conditions. We prove that it is a low and constitutively transcribed, membrane-anchored protein displayed on the cell surface. Furthermore, we also investigate the microbial groups possessing PET esterase coupled with the TPA degradation pathway, mainly in the phyla Proteobacteria and Actinobacteriota. Clarification of the microbial PET biodegradation in the marine environment will contribute to the understanding of bioremediation of marine PET pollution.
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Affiliation(s)
- Wenbin Guo
- Key Laboratory of Marine Biogenetic Resources, Third Institute of Oceanography, Ministry of Natural Resources, 361005, Xiamen, Fujian, China.
| | - Jingjing Duan
- College of Environment and Ecology, Xiamen University, 361005, Xiamen, Fujian, China.
| | - Zhengguang Shi
- Key Laboratory of Marine Biogenetic Resources, Third Institute of Oceanography, Ministry of Natural Resources, 361005, Xiamen, Fujian, China
- School of Advanced Manufacturing, Fuzhou University, 362251, Jinjiang, China
| | - Xue Yu
- Key Laboratory of Marine Biogenetic Resources, Third Institute of Oceanography, Ministry of Natural Resources, 361005, Xiamen, Fujian, China
- School of Advanced Manufacturing, Fuzhou University, 362251, Jinjiang, China
| | - Zongze Shao
- Key Laboratory of Marine Biogenetic Resources, Third Institute of Oceanography, Ministry of Natural Resources, 361005, Xiamen, Fujian, China
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40
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Krainara S, Mistry AN, Malee C, Chavananikul C, Pinyakong O, Assavalapsakul W, Jitpraphai SM, Kachenchart B, Luepromchai E. Development of a plastic waste treatment process by combining deep eutectic solvent (DES) pretreatment and bioaugmentation with a plastic-degrading bacterial consortium. JOURNAL OF HAZARDOUS MATERIALS 2023; 460:132507. [PMID: 37699265 DOI: 10.1016/j.jhazmat.2023.132507] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/19/2023] [Revised: 08/29/2023] [Accepted: 09/06/2023] [Indexed: 09/14/2023]
Abstract
Polyethylene terephthalate (PET), a petroleum-based plastic, and polylactic acid (PLA), a biobased plastic, have a similar visual appearance thus they usually end up in municipal waste treatment facilities. The objective of this project was to develop an effective PET and PLA waste treatment process that involves pretreatment with deep eutectic solvent (DES) followed by biodegradation with a plastic-degrading bacterial consortium in a composting system. The DES used was a mixture of choline chloride and glycerol, while the bacterial strains (Chitinophaga jiangningensis EA02, Nocardioides zeae EA12, Stenotrophomonas pavanii EA33, Gordonia desulfuricans EA63, Achromobacter xylosoxidans A9 and Mycolicibacterium parafortuitum J101) used to prepare the bacterial consortium were selected based on their ability to biodegrade PET, PLA, and plasticizer. The plastic samples (a PET bottle, PLA cup, and PLA film) were pretreated with DES through a dip-coating method. The DES-coated plastic samples exhibited higher surface wettability and biofilm formation, indicating that DES increases the hydrophilicity of the plastic and facilitates bacterial attachment to the plastic surface. The combined action of DES pretreatment and bioaugmentation with a plastic-degrading bacterial consortium led to improved degradation of PET and PLA samples in various environments, including aqueous media at ambient temperature, lab-scale traditional composting, and pilot-scale composting.
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Affiliation(s)
- Saowaluk Krainara
- Department of Environmental Health and Technology, School of Public Health, Walailak University, Nakhon Si Thammarat, Thailand; Excellent Center for Dengue and Community Public Health (EC for DACH), Walailak University, Nakhon Si Thammarat, Thailand; Center of Excellence in Microbial Technology for Marine Pollution Treatment (MiTMaPT), Department of Microbiology, Faculty of Science, Chulalongkorn University, Bangkok, Thailand
| | - Avnish Nitin Mistry
- Center of Excellence in Microbial Technology for Marine Pollution Treatment (MiTMaPT), Department of Microbiology, Faculty of Science, Chulalongkorn University, Bangkok, Thailand; Center of Excellence on Hazardous Substance Management (HSM), Chulalongkorn University, Bangkok, Thailand
| | - Chawanan Malee
- Faculty of Environment and Resource Studies, Mahidol University, Nakhon Pathom, Thailand
| | - Chutima Chavananikul
- International Program in Hazardous Substance and Environmental Management (IP-HSM), Graduate School, Chulalongkorn University, Bangkok, Thailand
| | - Onruthai Pinyakong
- Center of Excellence in Microbial Technology for Marine Pollution Treatment (MiTMaPT), Department of Microbiology, Faculty of Science, Chulalongkorn University, Bangkok, Thailand; Center of Excellence on Hazardous Substance Management (HSM), Chulalongkorn University, Bangkok, Thailand
| | - Wanchai Assavalapsakul
- Center of Excellence in Microbial Technology for Marine Pollution Treatment (MiTMaPT), Department of Microbiology, Faculty of Science, Chulalongkorn University, Bangkok, Thailand
| | - Somrudee Meprasert Jitpraphai
- Center of Excellence in Microbial Technology for Marine Pollution Treatment (MiTMaPT), Department of Microbiology, Faculty of Science, Chulalongkorn University, Bangkok, Thailand; Department of Marine Sciences, Faculty of Science, Chulalongkorn University, Bangkok, Thailand
| | - Boonlue Kachenchart
- Faculty of Environment and Resource Studies, Mahidol University, Nakhon Pathom, Thailand
| | - Ekawan Luepromchai
- Center of Excellence in Microbial Technology for Marine Pollution Treatment (MiTMaPT), Department of Microbiology, Faculty of Science, Chulalongkorn University, Bangkok, Thailand; Center of Excellence on Hazardous Substance Management (HSM), Chulalongkorn University, Bangkok, Thailand.
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Lee GH, Kim DW, Jin YH, Kim SM, Lim ES, Cha MJ, Ko JK, Gong G, Lee SM, Um Y, Han SO, Ahn JH. Biotechnological Plastic Degradation and Valorization Using Systems Metabolic Engineering. Int J Mol Sci 2023; 24:15181. [PMID: 37894861 PMCID: PMC10607142 DOI: 10.3390/ijms242015181] [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: 09/22/2023] [Revised: 10/10/2023] [Accepted: 10/13/2023] [Indexed: 10/29/2023] Open
Abstract
Various kinds of plastics have been developed over the past century, vastly improving the quality of life. However, the indiscriminate production and irresponsible management of plastics have led to the accumulation of plastic waste, emerging as a pressing environmental concern. To establish a clean and sustainable plastic economy, plastic recycling becomes imperative to mitigate resource depletion and replace non-eco-friendly processes, such as incineration. Although chemical and mechanical recycling technologies exist, the prevalence of composite plastics in product manufacturing complicates recycling efforts. In recent years, the biodegradation of plastics using enzymes and microorganisms has been reported, opening a new possibility for biotechnological plastic degradation and bio-upcycling. This review provides an overview of microbial strains capable of degrading various plastics, highlighting key enzymes and their role. In addition, recent advances in plastic waste valorization technology based on systems metabolic engineering are explored in detail. Finally, future perspectives on systems metabolic engineering strategies to develop a circular plastic bioeconomy are discussed.
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Affiliation(s)
- Ga Hyun Lee
- Clean Energy Research Center, Korea Institute of Science and Technology, Seoul 02792, Republic of Korea
- Department of Biotechnology, Korea University, Seoul 02841, Republic of Korea
| | - Do-Wook Kim
- Clean Energy Research Center, Korea Institute of Science and Technology, Seoul 02792, Republic of Korea
| | - Yun Hui Jin
- Clean Energy Research Center, Korea Institute of Science and Technology, Seoul 02792, Republic of Korea
- Department of Biotechnology, Korea University, Seoul 02841, Republic of Korea
| | - Sang Min Kim
- Clean Energy Research Center, Korea Institute of Science and Technology, Seoul 02792, Republic of Korea
- Department of Biotechnology, Korea University, Seoul 02841, Republic of Korea
| | - Eui Seok Lim
- Clean Energy Research Center, Korea Institute of Science and Technology, Seoul 02792, Republic of Korea
- Department of Biotechnology, Korea University, Seoul 02841, Republic of Korea
| | - Min Ji Cha
- Clean Energy Research Center, Korea Institute of Science and Technology, Seoul 02792, Republic of Korea
- Department of Biotechnology, Korea University, Seoul 02841, Republic of Korea
| | - Ja Kyong Ko
- Clean Energy Research Center, Korea Institute of Science and Technology, Seoul 02792, Republic of Korea
- Division of Energy and Environment Technology, KIST School, University of Science and Technology (UST), Daejeon 34113, Republic of Korea
| | - Gyeongtaek Gong
- Clean Energy Research Center, Korea Institute of Science and Technology, Seoul 02792, Republic of Korea
- Division of Energy and Environment Technology, KIST School, University of Science and Technology (UST), Daejeon 34113, Republic of Korea
| | - Sun-Mi Lee
- Clean Energy Research Center, Korea Institute of Science and Technology, Seoul 02792, Republic of Korea
- Division of Energy and Environment Technology, KIST School, University of Science and Technology (UST), Daejeon 34113, Republic of Korea
| | - Youngsoon Um
- Clean Energy Research Center, Korea Institute of Science and Technology, Seoul 02792, Republic of Korea
- Division of Energy and Environment Technology, KIST School, University of Science and Technology (UST), Daejeon 34113, Republic of Korea
| | - Sung Ok Han
- Department of Biotechnology, Korea University, Seoul 02841, Republic of Korea
| | - Jung Ho Ahn
- Clean Energy Research Center, Korea Institute of Science and Technology, Seoul 02792, Republic of Korea
- Division of Energy and Environment Technology, KIST School, University of Science and Technology (UST), Daejeon 34113, Republic of Korea
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42
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Duan S, Zhang N, Chao T, Wu Y, Wang M. The structural and molecular mechanisms of type II PETases: a mini review. Biotechnol Lett 2023; 45:1249-1263. [PMID: 37535135 DOI: 10.1007/s10529-023-03418-3] [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: 03/21/2023] [Accepted: 07/15/2023] [Indexed: 08/04/2023]
Abstract
The advent of plastics has led to significant advances for humans, although the accompanying pollution has also been a source of concern for countries globally. Consequently, a biological method to effectively degrade polyethylene terephthalate (PET) has been an area of significant scientific interest. Following the report of the highly efficient PET hydrolase from the bacterium Ideonella sakaiensis strain 201-F6 (i.e., IsPETase) in 2016, its structure has been extensively studied, showing that it belongs to the type II PETase group. Unlike type I PETases that include most known cutinases, structural investigations of type II PETases have only been conducted since 2017. Type II PETases are further divided into type IIa and IIb enzymes. Moreover, even less research has been conducted on type IIa plastic-degrading enzymes. Here, we present a review of recent studies of the structure and mechanism of type II PETases, using the known structure of the type IIa PETase PE-H from the marine bacterium Pseudomonas aestusnigri in addition to the type IIb enzyme IsPETase as representatives. These studies have provided new insights into the structural features of type II PETases that exhibit PET catalytic activity. In addition, recent studies investigating the rational design of IsPETases are reviewed and summarized alongside a discussion of controversies surrounding PETase investigations.
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Affiliation(s)
- Shuyan Duan
- College of Food Science and Pharmaceutical Engineering, Zaozhuang University, Zaozhuang, 277160, Shandong, China.
| | - Nan Zhang
- College of Food Science and Pharmaceutical Engineering, Zaozhuang University, Zaozhuang, 277160, Shandong, China
| | - Tianzhu Chao
- College of Food Science and Pharmaceutical Engineering, Zaozhuang University, Zaozhuang, 277160, Shandong, China
| | - Yaoyao Wu
- College of Food Science and Pharmaceutical Engineering, Zaozhuang University, Zaozhuang, 277160, Shandong, China
| | - Mengying Wang
- Department of Materials Science and Engineering, Southern University of Science and Technology, Shenzhen, 518055, Guangdong, China.
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43
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Liu F, Wang T, Yang W, Zhang Y, Gong Y, Fan X, Wang G, Lu Z, Wang J. Current advances in the structural biology and molecular engineering of PETase. Front Bioeng Biotechnol 2023; 11:1263996. [PMID: 37795175 PMCID: PMC10546322 DOI: 10.3389/fbioe.2023.1263996] [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: 07/20/2023] [Accepted: 08/31/2023] [Indexed: 10/06/2023] Open
Abstract
Poly(ethylene terephthalate) (PET) is a highly useful synthetic polyester plastic that is widely used in daily life. However, the increase in postconsumer PET as plastic waste that is recalcitrant to biodegradation in landfills and the natural environment has raised worldwide concern. Currently, traditional PET recycling processes with thermomechanical or chemical methods also result in the deterioration of the mechanical properties of PET. Therefore, it is urgent to develop more efficient and green strategies to address this problem. Recently, a novel mesophilic PET-degrading enzyme (IsPETase) from Ideonella sakaiensis was found to streamline PET biodegradation at 30°C, albeit with a lower PET-degrading activity than chitinase or chitinase-like PET-degrading enzymes. Consequently, the molecular engineering of more efficient PETases is still required for further industrial applications. This review details current knowledge on IsPETase, MHETase, and IsPETase-like hydrolases, including the structures, ligand‒protein interactions, and rational protein engineering for improved PET-degrading performance. In particular, applications of the engineered catalysts are highlighted, including metabolic engineering of the cell factories, enzyme immobilization or cell surface display. The information is expected to provide novel insights for the biodegradation of complex polymers.
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Affiliation(s)
- Fei Liu
- School of Biological Science, Jining Medical University, Rizhao, China
| | - Tao Wang
- School of Biological Science, Jining Medical University, Rizhao, China
| | - Wentao Yang
- School of Biological Science, Jining Medical University, Rizhao, China
| | - Yingkang Zhang
- School of Biological Science, Jining Medical University, Rizhao, China
| | - Yuming Gong
- School of Biological Science, Jining Medical University, Rizhao, China
| | - Xinxin Fan
- School of Biological Science, Jining Medical University, Rizhao, China
| | - Guocheng Wang
- School of Biological Science, Jining Medical University, Rizhao, China
| | - Zhenhua Lu
- College of Chemical and Biological Engineering, Zhejiang University, Hangzhou, Zhejiang, China
| | - Jianmin Wang
- School of Pharmacy, Jining Medical University, Rizhao, China
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44
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Perez-Garcia P, Chow J, Costanzi E, Gurschke M, Dittrich J, Dierkes RF, Molitor R, Applegate V, Feuerriegel G, Tete P, Danso D, Thies S, Schumacher J, Pfleger C, Jaeger KE, Gohlke H, Smits SHJ, Schmitz RA, Streit WR. An archaeal lid-containing feruloyl esterase degrades polyethylene terephthalate. Commun Chem 2023; 6:193. [PMID: 37697032 PMCID: PMC10495362 DOI: 10.1038/s42004-023-00998-z] [Citation(s) in RCA: 11] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2023] [Accepted: 08/31/2023] [Indexed: 09/13/2023] Open
Abstract
Polyethylene terephthalate (PET) is a commodity polymer known to globally contaminate marine and terrestrial environments. Today, around 80 bacterial and fungal PET-active enzymes (PETases) are known, originating from four bacterial and two fungal phyla. In contrast, no archaeal enzyme had been identified to degrade PET. Here we report on the structural and biochemical characterization of PET46 (RLI42440.1), an archaeal promiscuous feruloyl esterase exhibiting degradation activity on semi-crystalline PET powder comparable to IsPETase and LCC (wildtypes), and higher activity on bis-, and mono-(2-hydroxyethyl) terephthalate (BHET and MHET). The enzyme, found by a sequence-based metagenome search, is derived from a non-cultivated, deep-sea Candidatus Bathyarchaeota archaeon. Biochemical characterization demonstrated that PET46 is a promiscuous, heat-adapted hydrolase. Its crystal structure was solved at a resolution of 1.71 Å. It shares the core alpha/beta-hydrolase fold with bacterial PETases, but contains a unique lid common in feruloyl esterases, which is involved in substrate binding. Thus, our study widens the currently known diversity of PET-hydrolyzing enzymes, by demonstrating PET depolymerization by a plant cell wall-degrading esterase.
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Affiliation(s)
- Pablo Perez-Garcia
- Department of Microbiology and Biotechnology, University of Hamburg, Hamburg, Germany
- Institute for General Microbiology, Christian-Albrechts-Universität zu Kiel, Kiel, Germany
| | - Jennifer Chow
- Department of Microbiology and Biotechnology, University of Hamburg, Hamburg, Germany
| | - Elisa Costanzi
- Center for Structural Studies (CSS), Heinrich Heine University Düsseldorf, Düsseldorf, Germany
| | - Marno Gurschke
- Department of Microbiology and Biotechnology, University of Hamburg, Hamburg, Germany
| | - Jonas Dittrich
- Institute for Pharmaceutical and Medicinal Chemistry, Heinrich Heine University Düsseldorf, Düsseldorf, Germany
| | - Robert F Dierkes
- Department of Microbiology and Biotechnology, University of Hamburg, Hamburg, Germany
| | - Rebecka Molitor
- Institute of Molecular Enzyme Technology (IMET), Heinrich Heine University Düsseldorf, Jülich, Germany
| | - Violetta Applegate
- Center for Structural Studies (CSS), Heinrich Heine University Düsseldorf, Düsseldorf, Germany
| | - Golo Feuerriegel
- Department of Microbiology and Biotechnology, University of Hamburg, Hamburg, Germany
| | - Prince Tete
- Department of Microbiology and Biotechnology, University of Hamburg, Hamburg, Germany
| | - Dominik Danso
- Department of Microbiology and Biotechnology, University of Hamburg, Hamburg, Germany
| | - Stephan Thies
- Institute of Molecular Enzyme Technology (IMET), Heinrich Heine University Düsseldorf, Jülich, Germany
| | - Julia Schumacher
- Center for Structural Studies (CSS), Heinrich Heine University Düsseldorf, Düsseldorf, Germany
| | - Christopher Pfleger
- Institute for Pharmaceutical and Medicinal Chemistry, Heinrich Heine University Düsseldorf, Düsseldorf, Germany
| | - Karl-Erich Jaeger
- Institute of Molecular Enzyme Technology (IMET), Heinrich Heine University Düsseldorf, Jülich, Germany
- Institute of Bio- and Geosciences IBG-1: Biotechnology, Forschungszentrum Jülich GmbH, Jülich, Germany
| | - Holger Gohlke
- Institute for Pharmaceutical and Medicinal Chemistry, Heinrich Heine University Düsseldorf, Düsseldorf, Germany
- Institute for Bio- and Geosciences (IBG-4: Bioinformatics), Forschungszentrum Jülich, Jülich, Germany
| | - Sander H J Smits
- Center for Structural Studies (CSS), Heinrich Heine University Düsseldorf, Düsseldorf, Germany
- Institute for Biochemistry, Heinrich Heine University Düsseldorf, Düsseldorf, Germany
| | - Ruth A Schmitz
- Institute for General Microbiology, Christian-Albrechts-Universität zu Kiel, Kiel, Germany.
| | - Wolfgang R Streit
- Department of Microbiology and Biotechnology, University of Hamburg, Hamburg, Germany.
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45
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Blázquez‐Sánchez P, Vargas JA, Furtado AA, Griñen A, Leonardo DA, Sculaccio SA, Pereira HD, Sonnendecker C, Zimmermann W, Díez B, Garratt RC, Ramírez‐Sarmiento CA. Engineering the catalytic activity of an Antarctic PET-degrading enzyme by loop exchange. Protein Sci 2023; 32:e4757. [PMID: 37574805 PMCID: PMC10464292 DOI: 10.1002/pro.4757] [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: 05/16/2023] [Revised: 08/09/2023] [Accepted: 08/10/2023] [Indexed: 08/15/2023]
Abstract
Several hydrolases have been described to degrade polyethylene terephthalate (PET) at moderate temperatures ranging from 25°C to 40°C. These mesophilic PET hydrolases (PETases) are less efficient in degrading this plastic polymer than their thermophilic homologs and have, therefore, been the subject of many protein engineering campaigns. However, enhancing their enzymatic activity through rational design or directed evolution poses a formidable challenge due to the need for exploring a large number of mutations. Additionally, evaluating the improvements in both activity and stability requires screening numerous variants, either individually or using high-throughput screening methods. Here, we utilize instead the design of chimeras as a protein engineering strategy to increase the activity and stability of Mors1, an Antarctic PETase active at 25°C. First, we obtained the crystal structure of Mors1 at 1.6 Å resolution, which we used as a scaffold for structure- and sequence-based chimeric design. Then, we designed a Mors1 chimera via loop exchange of a highly divergent active site loop from the thermophilic leaf-branch compost cutinase (LCC) into the equivalent region in Mors1. After restitution of an active site disulfide bond into this chimera, the enzyme exhibited a shift in optimal temperature for activity to 45°C and an increase in fivefold in PET hydrolysis when compared with wild-type Mors1 at 25°C. Our results serve as a proof of concept of the utility of chimeric design to further improve the activity and stability of PETases active at moderate temperatures.
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Affiliation(s)
- Paula Blázquez‐Sánchez
- Institute for Biological and Medical Engineering, Schools of Engineering, Medicine and Biological SciencesPontificia Universidad Católica de ChileSantiagoChile
- ANID—Millennium Science Initiative ProgramMillennium Institute for Integrative Biology (iBio)SantiagoChile
- Institute of Analytical ChemistryLeipzig UniversityLeipzigGermany
| | - Jhon A. Vargas
- São Carlos Institute of PhysicsUniversity of São PauloSão CarlosBrazil
| | | | - Aransa Griñen
- Institute for Biological and Medical Engineering, Schools of Engineering, Medicine and Biological SciencesPontificia Universidad Católica de ChileSantiagoChile
- ANID—Millennium Science Initiative ProgramMillennium Institute for Integrative Biology (iBio)SantiagoChile
| | - Diego A. Leonardo
- São Carlos Institute of PhysicsUniversity of São PauloSão CarlosBrazil
| | | | | | | | | | - Beatriz Díez
- Department of Molecular Genetics and Microbiology, School of Biological SciencesPontificia Universidad Católica de ChileSantiagoChile
- Center for Climate and Resilience Research (CR)SantiagoChile
- Millennium Institute Center for Genome Regulation (CGR)SantiagoChile
| | | | - César A. Ramírez‐Sarmiento
- Institute for Biological and Medical Engineering, Schools of Engineering, Medicine and Biological SciencesPontificia Universidad Católica de ChileSantiagoChile
- ANID—Millennium Science Initiative ProgramMillennium Institute for Integrative Biology (iBio)SantiagoChile
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46
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Kim JH, Lee SH, Lee BM, Son KH, Park HY. Biodegradation Potential of Polyethylene Terephthalate by the Two Insect Gut Symbionts Xanthomonas sp. HY-74 and Bacillus sp. HY-75. Polymers (Basel) 2023; 15:3546. [PMID: 37688172 PMCID: PMC10489954 DOI: 10.3390/polym15173546] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2023] [Revised: 08/17/2023] [Accepted: 08/23/2023] [Indexed: 09/10/2023] Open
Abstract
Polyethylene terephthalate (PET) is a plastic material that is widely used in beverage bottles, food packaging, and other consumer products, which is highly resistant to biodegradation. In this study, we investigated the effects of two insect gut symbionts, Xanthomonas sp. HY-74 and Bacillus sp. HY-75, during PET biodegradation. Both strains degraded PET-containing agar plates, and the sole nutrition source assay showed that HY-74 had different degradation rates depending on the presence of specific carbon and nitrogen sources, whereas HY-75 exhibited comparable degradation across all tested conditions. The two strains biodegraded the PET film with 1.57 ± 0.21% and 1.42 ± 0.46% weight loss after 6 weeks, respectively. Changes in the morphology and structure of the PET films, such as erosion, scratching, and surface roughening, were determined using scanning electron microscopy (SEM). Further, the two strains biodegraded PET powder, broke it into its degradation products, and changed the surface functional groups. This is the first study to investigate the biodegradation of PET by Hymenoptera gut-derived microbes and offers promising insights into the potential applications of insect gut symbionts in PET waste management.
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Affiliation(s)
| | | | | | | | - Ho-Yong Park
- Microbiome Convergence Research Center, Korea Research Institute of Bioscience and Biotechnology, Daejeon 34141, Republic of Korea; (J.-H.K.); (S.-H.L.); (B.-M.L.); (K.-H.S.)
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47
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Chan DTC, Baldwin GS, Bernstein HC. Revealing the Host-Dependent Nature of an Engineered Genetic Inverter in Concordance with Physiology. BIODESIGN RESEARCH 2023; 5:0016. [PMID: 37849456 PMCID: PMC10432152 DOI: 10.34133/bdr.0016] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2023] [Accepted: 07/17/2023] [Indexed: 10/19/2023] Open
Abstract
Broad-host-range synthetic biology is an emerging frontier that aims to expand our current engineerable domain of microbial hosts for biodesign applications. As more novel species are brought to "model status," synthetic biologists are discovering that identically engineered genetic circuits can exhibit different performances depending on the organism it operates within, an observation referred to as the "chassis effect." It remains a major challenge to uncover which genome-encoded and biological determinants will underpin chassis effects that govern the performance of engineered genetic devices. In this study, we compared model and novel bacterial hosts to ask whether phylogenomic relatedness or similarity in host physiology is a better predictor of genetic circuit performance. This was accomplished using a comparative framework based on multivariate statistical approaches to systematically demonstrate the chassis effect and characterize the performance dynamics of a genetic inverter circuit operating within 6 Gammaproteobacteria. Our results solidify the notion that genetic devices are strongly impacted by the host context. Furthermore, we formally determined that hosts exhibiting more similar metrics of growth and molecular physiology also exhibit more similar performance of the genetic inverter, indicating that specific bacterial physiology underpins measurable chassis effects. The result of this study contributes to the field of broad-host-range synthetic biology by lending increased predictive power to the implementation of genetic devices in less-established microbial hosts.
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Affiliation(s)
- Dennis Tin Chat Chan
- Faculty of Biosciences, Fisheries and Economics, UiT, The Arctic University of Norway, 9019 Tromsø, Norway
| | - Geoff S. Baldwin
- Department of Life Sciences, Imperial College London, South Kensington, London SW7 2AZ, UK
- Imperial College Centre for Synthetic Biology, Imperial College London, South Kensington, London SW7 2AZ, UK
| | - Hans C. Bernstein
- Faculty of Biosciences, Fisheries and Economics, UiT, The Arctic University of Norway, 9019 Tromsø, Norway
- The Arctic Centre for Sustainable Energy, UiT, The Arctic University of Norway, 9019 Tromsø, Norway
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48
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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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49
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Carr CM, Keller MB, Paul B, Schubert SW, Clausen KSR, Jensen K, Clarke DJ, Westh P, Dobson ADW. Purification and biochemical characterization of SM14est, a PET-hydrolyzing enzyme from the marine sponge-derived Streptomyces sp. SM14. Front Microbiol 2023; 14:1170880. [PMID: 37250061 PMCID: PMC10213408 DOI: 10.3389/fmicb.2023.1170880] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2023] [Accepted: 04/21/2023] [Indexed: 05/31/2023] Open
Abstract
The successful enzymatic degradation of polyester substrates has fueled worldwide investigation into the treatment of plastic waste using bio-based processes. Within this realm, marine-associated microorganisms have emerged as a promising source of polyester-degrading enzymes. In this work, we describe the hydrolysis of the synthetic polymer PET by SM14est, a polyesterase which was previously identified from Streptomyces sp. SM14, an isolate of the marine sponge Haliclona simulans. The PET hydrolase activity of purified SM14est was assessed using a suspension-based assay and subsequent analysis of reaction products by UV-spectrophotometry and RP-HPLC. SM14est displayed a preference for high salt conditions, with activity significantly increasing at sodium chloride concentrations from 100 mM up to 1,000 mM. The initial rate of PET hydrolysis by SM14est was determined to be 0.004 s-1 at 45°C, which was increased by 5-fold to 0.02 s-1 upon addition of 500 mM sodium chloride. Sequence alignment and structural comparison with known PET hydrolases, including the marine halophile PET6, and the highly efficient, thermophilic PHL7, revealed conserved features of interest. Based on this work, SM14est emerges as a useful enzyme that is more similar to key players in the area of PET hydrolysis, like PHL7 and IsPETase, than it is to its marine counterparts. Salt-tolerant polyesterases such as SM14est are potentially valuable in the biological degradation of plastic particles that readily contaminate marine ecosystems and industrial wastewaters.
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Affiliation(s)
- Clodagh M. Carr
- School of Microbiology, University College Cork, Cork, Ireland
- SSPC-SFI Research Centre for Pharmaceuticals, University College Cork, Cork, Ireland
| | - Malene B. Keller
- Department of Biotechnology and Biomedicine, Technical University of Denmark, Lyngby, Denmark
| | - Bijoya Paul
- Department of Biotechnology and Biomedicine, Technical University of Denmark, Lyngby, Denmark
| | - Sune W. Schubert
- Department of Biotechnology and Biomedicine, Technical University of Denmark, Lyngby, Denmark
| | - Kristine S. R. Clausen
- Department of Biotechnology and Biomedicine, Technical University of Denmark, Lyngby, Denmark
| | | | - David J. Clarke
- School of Microbiology, University College Cork, Cork, Ireland
- APC Microbiome Ireland, University College Cork, Cork, Ireland
| | - Peter Westh
- Department of Biotechnology and Biomedicine, Technical University of Denmark, Lyngby, Denmark
| | - Alan D. W. Dobson
- School of Microbiology, University College Cork, Cork, Ireland
- SSPC-SFI Research Centre for Pharmaceuticals, University College Cork, Cork, Ireland
- Environmental Research Institute, University College Cork, Cork, Ireland
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50
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Richter PK, Blázquez-Sánchez P, Zhao Z, Engelberger F, Wiebeler C, Künze G, Frank R, Krinke D, Frezzotti E, Lihanova Y, Falkenstein P, Matysik J, Zimmermann W, Sträter N, Sonnendecker C. Structure and function of the metagenomic plastic-degrading polyester hydrolase PHL7 bound to its product. Nat Commun 2023; 14:1905. [PMID: 37019924 PMCID: PMC10076380 DOI: 10.1038/s41467-023-37415-x] [Citation(s) in RCA: 13] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2022] [Accepted: 03/16/2023] [Indexed: 04/07/2023] Open
Abstract
The recently discovered metagenomic-derived polyester hydrolase PHL7 is able to efficiently degrade amorphous polyethylene terephthalate (PET) in post-consumer plastic waste. We present the cocrystal structure of this hydrolase with its hydrolysis product terephthalic acid and elucidate the influence of 17 single mutations on the PET-hydrolytic activity and thermal stability of PHL7. The substrate-binding mode of terephthalic acid is similar to that of the thermophilic polyester hydrolase LCC and deviates from the mesophilic IsPETase. The subsite I modifications L93F and Q95Y, derived from LCC, increased the thermal stability, while exchange of H185S, derived from IsPETase, reduced the stability of PHL7. The subsite II residue H130 is suggested to represent an adaptation for high thermal stability, whereas L210 emerged as the main contributor to the observed high PET-hydrolytic activity. Variant L210T showed significantly higher activity, achieving a degradation rate of 20 µm h-1 with amorphous PET films.
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Affiliation(s)
- P Konstantin Richter
- Institute of Bioanalytical Chemistry, Centre for Biotechnology and Biomedicine, Leipzig University, Leipzig, Germany
| | | | - Ziyue Zhao
- Institute of Analytical Chemistry, Leipzig University, Leipzig, Germany
| | - Felipe Engelberger
- Institute for Drug Discovery, Leipzig University Medical School, Leipzig, Germany
| | - Christian Wiebeler
- Institute of Analytical Chemistry, Leipzig University, Leipzig, Germany
- Wilhelm-Ostwald-Institute for Physical and Theoretical Chemistry, Leipzig University, Leipzig, Germany
| | - Georg Künze
- Institute for Drug Discovery, Leipzig University Medical School, Leipzig, Germany
| | - Ronny Frank
- Centre for Biotechnology and Biomedicine, Molecular Biological-Biochemical Processing Technology, Leipzig University, Leipzig, Germany
| | - Dana Krinke
- Centre for Biotechnology and Biomedicine, Molecular Biological-Biochemical Processing Technology, Leipzig University, Leipzig, Germany
| | - Emanuele Frezzotti
- Department of Chemical Life and Environmental Sciences, University of Parma, Parma, Italy
| | - Yuliia Lihanova
- Institute of Analytical Chemistry, Leipzig University, Leipzig, Germany
| | | | - Jörg Matysik
- Institute of Analytical Chemistry, Leipzig University, Leipzig, Germany
| | | | - Norbert Sträter
- Institute of Bioanalytical Chemistry, Centre for Biotechnology and Biomedicine, Leipzig University, Leipzig, Germany.
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