1
|
Wang C, Long R, Lin X, Liu W, Zhu L, Jiang L. Development and characterization of a bacterial enzyme cascade reaction system for efficient and stable PET degradation. JOURNAL OF HAZARDOUS MATERIALS 2024; 472:134480. [PMID: 38703683 DOI: 10.1016/j.jhazmat.2024.134480] [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: 03/07/2024] [Revised: 04/15/2024] [Accepted: 04/27/2024] [Indexed: 05/06/2024]
Abstract
The widespread use of polyethylene terephthalate (PET) in various industries has led to a surge in microplastics (MPs) pollution, posing a significant threat to ecosystems and human health. To address this, we have developed a bacterial enzyme cascade reaction system (BECRS) that focuses on the efficient degradation of PET. This system harnesses the Escherichia coli (E. coli) surface to display CsgA protein, which forms curli fibers, along with the carbohydrate-binding module 3 (CBM3) and PETases, to enhance the adsorption and degradation of PET. The study demonstrated that the BECRS achieved a notable PET film degradation rate of 3437 ± 148 μg/(d*cm²), with a degradation efficiency of 21.40% for crystalline PET MPs, and the degradation products were all converted to TPA. The stability of the system was evidenced by retaining over 80% of its original activity after multiple uses and during one month of storage. Molecular dynamics simulations confirmed that the presence of CsgA did not interfere with the enzymatic activity of PETases. This BECRS represents a significant step forward in the biodegradation of PET, particularly microplastics, offering a practical and sustainable solution for environmental pollution control.
Collapse
Affiliation(s)
- Chengyong Wang
- State Key Laboratory of Materials-Oriented Chemical Engineering, Nanjing Tech University, Nanjing 211816, China; College of Biotechnology and Pharmaceutical Engineering, Nanjing Tech University, Nanjing 211816, China
| | - Rui Long
- College of Food Science and Light Industry, Nanjing Tech University, Nanjing 211816, China
| | - Xiran Lin
- College of Biotechnology and Pharmaceutical Engineering, Nanjing Tech University, Nanjing 211816, China
| | - Wei Liu
- College of Food Science and Light Industry, Nanjing Tech University, Nanjing 211816, China
| | - Liying Zhu
- College of Chemistry and Molecular Engineering, Nanjing Tech University, Nanjing 211816, China
| | - Ling Jiang
- State Key Laboratory of Materials-Oriented Chemical Engineering, Nanjing Tech University, Nanjing 211816, China; College of Food Science and Light Industry, Nanjing Tech University, Nanjing 211816, China.
| |
Collapse
|
2
|
Kawai F, Iizuka R, Kawabata T. Engineered polyethylene terephthalate hydrolases: perspectives and limits. Appl Microbiol Biotechnol 2024; 108:404. [PMID: 38953996 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] [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.
Collapse
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
| |
Collapse
|
3
|
Ndochinwa OG, Wang QY, Amadi OC, Nwagu TN, Nnamchi CI, Okeke ES, Moneke AN. Current status and emerging frontiers in enzyme engineering: An industrial perspective. Heliyon 2024; 10:e32673. [PMID: 38912509 PMCID: PMC11193041 DOI: 10.1016/j.heliyon.2024.e32673] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2023] [Revised: 06/05/2024] [Accepted: 06/06/2024] [Indexed: 06/25/2024] Open
Abstract
Protein engineering mechanisms can be an efficient approach to enhance the biochemical properties of various biocatalysts. Immobilization of biocatalysts and the introduction of new-to-nature chemical reactivities are also possible through the same mechanism. Discovering new protocols that enhance the catalytic active protein that possesses novelty in terms of being stable, active, and, stereoselectivity with functions could be identified as essential areas in terms of concurrent bioorganic chemistry (synergistic relationship between organic chemistry and biochemistry in the context of enzyme engineering). However, with our current level of knowledge about protein folding and its correlation with protein conformation and activities, it is almost impossible to design proteins with specific biological and physical properties. Hence, contemporary protein engineering typically involves reprogramming existing enzymes by mutagenesis to generate new phenotypes with desired properties. These processes ensure that limitations of naturally occurring enzymes are not encountered. For example, researchers have engineered cellulases and hemicellulases to withstand harsh conditions encountered during biomass pretreatment, such as high temperatures and acidic environments. By enhancing the activity and robustness of these enzymes, biofuel production becomes more economically viable and environmentally sustainable. Recent trends in enzyme engineering have enabled the development of tailored biocatalysts for pharmaceutical applications. For instance, researchers have engineered enzymes such as cytochrome P450s and amine oxidases to catalyze challenging reactions involved in drug synthesis. In addition to conventional methods, there has been an increasing application of machine learning techniques to identify patterns in data. These patterns are then used to predict protein structures, enhance enzyme solubility, stability, and function, forecast substrate specificity, and assist in rational protein design. In this review, we discussed recent trends in enzyme engineering to optimize the biochemical properties of various biocatalysts. Using examples relevant to biotechnology in engineering enzymes, we try to expatiate the significance of enzyme engineering with how these methods could be applied to optimize the biochemical properties of a naturally occurring enzyme.
Collapse
Affiliation(s)
- Obinna Giles Ndochinwa
- Department of Microbiology, Faculty of Biological Science, University of Nigeria, Nsukka, Nigeria
| | - Qing-Yan Wang
- State Key Laboratory of Biomass Enzyme Technology, National Engineering Research Center for Non-Food Biorefinery, Guangxi Academy of Sciences, Nanning, Guangxi, China
| | - Oyetugo Chioma Amadi
- Department of Microbiology, Faculty of Biological Science, University of Nigeria, Nsukka, Nigeria
| | - Tochukwu Nwamaka Nwagu
- Department of Microbiology, Faculty of Biological Science, University of Nigeria, Nsukka, Nigeria
| | | | - Emmanuel Sunday Okeke
- Department of Biochemistry, Faculty of Biological Sciences & Natural Science Unit, School of General Studies, University of Nigeria, Nsukka, Enugu State, 410001, Nigeria
- Institute of Environmental Health and Ecological Security, School of the Environment and Safety, Jiangsu University, 301 Xuefu Rd., 212013, Zhenjiang, Jiangsu, China
| | - Anene Nwabu Moneke
- Department of Microbiology, Faculty of Biological Science, University of Nigeria, Nsukka, Nigeria
| |
Collapse
|
4
|
Feng J, Li H, Lu Y, Li R, Cavaco-Paulo A, Fu J. Non-ionic surfactant PEG: Enhanced cutinase-catalyzed hydrolysis of polyethylene terephthalate. Int J Biol Macromol 2024; 273:133049. [PMID: 38857727 DOI: 10.1016/j.ijbiomac.2024.133049] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2024] [Revised: 05/16/2024] [Accepted: 06/07/2024] [Indexed: 06/12/2024]
Abstract
To enhance the enzymatic digestibility of polyethylene terephthalate (PET), which is highly oriented and crystallized, a polyethylene glycol (PEG) surfactant of varying molecular weights was utilized to improve the stability of mutant cutinase from Humicola insolens (HiC) and to increase the accessibility of the enzyme to the substrate. Leveraging the optimal conditions for HiC hydrolysis of PET, the introduction of 1 % w/v PEG significantly increased the yield of PET hydrolysis products. PEG600 was particularly effective, increasing the yield by 64.58 % compared to using HiC alone. Moreover, the mechanisms by which PEG600 and PEG6000 enhance enzyme digestion were extensively examined using circular dichroism and fluorescence spectroscopy. The results from CD and fluorescence analyses indicated that PEG alters the protein conformation, thereby affecting the catalytic effect of the enzyme. Moreover, PEG improved the affinity between HiC and PET by lowering the surface tension of the solution, substantially enhancing PET hydrolysis. This study suggests that PEG holds considerable promise as an enzyme protector, significantly aiding in the hydrophilic modification and degradation of PET in an environmentally friendly and sustainable manner.
Collapse
Affiliation(s)
- Jundan Feng
- Jiangsu Engineering Technology Research Centre for Functional Textiles, Jiangnan University, No.1800 Lihu Avenue, Wuxi, China
| | - Huimin Li
- Jiangsu Engineering Technology Research Centre for Functional Textiles, Jiangnan University, No.1800 Lihu Avenue, Wuxi, China
| | - Yuzheng Lu
- Jiangsu Engineering Technology Research Centre for Functional Textiles, Jiangnan University, No.1800 Lihu Avenue, Wuxi, China; Mechanical Engineering College, Tarim University, Alar, Xinjiang, China
| | - Rong Li
- Jiangsu Engineering Technology Research Centre for Functional Textiles, Jiangnan University, No.1800 Lihu Avenue, Wuxi, China
| | | | - Jiajia Fu
- Jiangsu Engineering Technology Research Centre for Functional Textiles, Jiangnan University, No.1800 Lihu Avenue, Wuxi, China.
| |
Collapse
|
5
|
Świderek K, Martí S, Arafet K, Moliner V. Computational study of the mechanism of a polyurethane esterase A (PueA) from Pseudomonas chlororaphis. Faraday Discuss 2024. [PMID: 38836643 DOI: 10.1039/d4fd00022f] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/06/2024]
Abstract
The effective management of plastic waste has become a global imperative, given our reliance on a linear model in which plastics are manufactured, used once, and then discarded. This has led to the pervasive accumulation of plastic debris in landfills and environmental contamination. Recognizing this issue, numerous initiatives are underway to address the environmental repercussions associated with plastic disposal. In this study, we investigate the possible molecular mechanism of polyurethane esterase A (PueA), which has been previously identified as responsible for the degradation of a polyester polyurethane (PU) sample in Pseudomonas chlororaphis, as an effort to develop enzymatic biodegradation solutions. After generating the unsolved 3D structure of the protein by AlphaFold2 from its known genome, the enzymatic hydrolysis of the same model PU compound previously used in experiments has been explored employing QM/MM molecular dynamics simulations. This required a preliminary analysis of the 3D structure of the apo-enzyme, identifying the putative active site, and the search for the optimal protein-substrate binding site. Finally, the resulting free energy landscape indicates that wild-type PueA can degrade PU chains, although with low-level activity. The reaction takes place by a characteristic four-step path of the serine hydrolases, involving an acylation followed by a diacylation step. Energetics and structural analysis of the evolution of the active site along the reaction suggests that PueA can be considered a promising protein scaffold for further development to achieve efficient biodegradation of PU.
Collapse
Affiliation(s)
- Katarzyna Świderek
- BioComp Group, Institute of Advanced Materials (INAM), Universitat Jaume I, 12071 Castellón, Spain.
| | - Sergio Martí
- BioComp Group, Institute of Advanced Materials (INAM), Universitat Jaume I, 12071 Castellón, Spain.
| | - Kemel Arafet
- BioComp Group, Institute of Advanced Materials (INAM), Universitat Jaume I, 12071 Castellón, Spain.
| | - Vicent Moliner
- BioComp Group, Institute of Advanced Materials (INAM), Universitat Jaume I, 12071 Castellón, Spain.
| |
Collapse
|
6
|
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.
Collapse
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
| |
Collapse
|
7
|
Zhang Y, Hancock WO. Measuring PETase enzyme kinetics by single-molecule microscopy. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.04.24.590935. [PMID: 38712273 PMCID: PMC11071475 DOI: 10.1101/2024.04.24.590935] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/08/2024]
Abstract
Polyethylene terephthalate (PET) is one of the most widely produced man-made polymers and is a significant contributor to microplastics pollution. The environmental and human health impacts of microplastics pollution have motivated a concerted effort to develop microbe- and enzyme-based strategies to degrade PET and similar plastics. A PETase derived from the bacteria Ideonella sakaiensis was previously shown to enzymatically degrade PET, triggering multidisciplinary efforts to improve the robustness and activity of this and other PETases. However, because these enzymes only erode the surface of the insoluble PET substrate, it is difficult to measure standard kinetic parameters, such as kon, koff and kcat, complicating interpretation of the activity of mutants using traditional enzyme kinetics frameworks. To address this challenge, we developed a single-molecule microscopy assay that quantifies the landing rate and binding duration of quantum dot-labeled PETase enzymes interacting with a surface-immobilized PET film. Wild-type PETase binding durations were well fit by a biexponential with a fast population having a 2.7 s time constant, interpreted as active binding events, and a slow population interpreted as non-specific binding interactions that last tens of seconds. A previously described hyperactive mutant, S238F/W159H had both a faster on-rate and a slower off-rate than wild-type PETase, potentially explaining its enhanced activity. Because this single-molecule approach provides a more detailed mechanistic picture of PETase enzymatic activity than standard bulk assays, it should aid future efforts to engineer more robust and active PETases to combat global microplastics pollution.
Collapse
Affiliation(s)
- Yuwei Zhang
- Department of Biomedical Engineering, Pennsylvania State University, University Park, Pennsylvania, USA
| | - William O. Hancock
- Department of Biomedical Engineering, Pennsylvania State University, University Park, Pennsylvania, USA
- Department of Chemistry, Pennsylvania State University, University Park, Pennsylvania, USA
| |
Collapse
|
8
|
Liu J, Xin K, Zhang T, Wen Y, Li D, Wei R, Zhou J, Cui Z, Dong W, Jiang M. Identification and characterization of a fungal cutinase-like enzyme CpCut1 from Cladosporium sp. P7 for polyurethane degradation. Appl Environ Microbiol 2024; 90:e0147723. [PMID: 38445906 PMCID: PMC11022569 DOI: 10.1128/aem.01477-23] [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: 08/29/2023] [Accepted: 02/07/2024] [Indexed: 03/07/2024] Open
Abstract
Plastic degradation by biological systems emerges as a prospective avenue for addressing the pressing global concern of plastic waste accumulation. The intricate chemical compositions and diverse structural facets inherent to polyurethanes (PU) substantially increase the complexity associated with PU waste management. Despite the extensive research endeavors spanning over decades, most known enzymes exhibit a propensity for hydrolyzing waterborne PU dispersion (i.e., the commercial Impranil DLN-SD), with only a limited capacity for the degradation of bulky PU materials. Here, we report a novel cutinase (CpCut1) derived from Cladosporium sp. P7, which demonstrates remarkable efficiency in the degrading of various polyester-PU materials. After 12-h incubation at 55°C, CpCut1 was capable of degrading 40.5% and 20.6% of thermoplastic PU film and post-consumer foam, respectively, while achieving complete depolymerization of Impranil DLN-SD. Further analysis of the degradation intermediates suggested that the activity of CpCut1 primarily targeted the ester bonds within the PU soft segments. The versatile performance of CpCut1 against a spectrum of polyester-PU materials positions it as a promising candidate for the bio-recycling of waste plastics.IMPORTANCEPolyurethane (PU) has a complex chemical composition that frequently incorporates a variety of additives, which poses significant obstacles to biodegradability and recyclability. Recent advances have unveiled microbial degradation and enzymatic depolymerization as promising waste PU disposal strategies. In this study, we identified a gene encoding a cutinase from the PU-degrading fungus Cladosporium sp. P7, which allowed the expression, purification, and characterization of the recombinant enzyme CpCut1. Furthermore, this study identified the products derived from the CpCut1 catalyzed PU degradation and proposed its underlying mechanism. These findings highlight the potential of this newly discovered fungal cutinase as a remarkably efficient tool in the degradation of PU materials.
Collapse
Affiliation(s)
- Jiawei Liu
- Key Laboratory for Waste Plastics Biocatalytic Degradation and Recycling, College of Biotechnology and Pharmaceutical Engineering, Nanjing Tech University, Nanjing, China
| | - Kaiyuan Xin
- Key Laboratory for Waste Plastics Biocatalytic Degradation and Recycling, College of Biotechnology and Pharmaceutical Engineering, Nanjing Tech University, Nanjing, China
| | - Tianyang Zhang
- Key Laboratory for Waste Plastics Biocatalytic Degradation and Recycling, College of Biotechnology and Pharmaceutical Engineering, Nanjing Tech University, Nanjing, China
| | - Yuan Wen
- Key Laboratory for Waste Plastics Biocatalytic Degradation and Recycling, College of Biotechnology and Pharmaceutical Engineering, Nanjing Tech University, Nanjing, China
| | - Ding Li
- Institute of Veterinary Immunology & Engineering, Jiangsu Academy of Agricultural Sciences, Nanjing, China
| | - Ren Wei
- Junior Research Group Plastic Biodegradation, Department of Biotechnology and Enzyme Catalysis, Institute of Biochemistry, University of Greifswald, Greifswald, Germany
| | - Jie Zhou
- Key Laboratory for Waste Plastics Biocatalytic Degradation and Recycling, College of Biotechnology and Pharmaceutical Engineering, Nanjing Tech University, Nanjing, China
- State Key Laboratory of Materials-Oriented Chemical Engineering, Nanjing Tech University, Nanjing, China
| | - Zhongli Cui
- Key Laboratory of Agricultural Environmental Microbiology, Ministry of Agriculture, College of Life Sciences, Nanjing Agricultural University, Nanjing, China
| | - Weiliang Dong
- Key Laboratory for Waste Plastics Biocatalytic Degradation and Recycling, College of Biotechnology and Pharmaceutical Engineering, Nanjing Tech University, Nanjing, China
- State Key Laboratory of Materials-Oriented Chemical Engineering, Nanjing Tech University, Nanjing, China
| | - Min Jiang
- Key Laboratory for Waste Plastics Biocatalytic Degradation and Recycling, College of Biotechnology and Pharmaceutical Engineering, Nanjing Tech University, Nanjing, China
- State Key Laboratory of Materials-Oriented Chemical Engineering, Nanjing Tech University, Nanjing, China
| |
Collapse
|
9
|
Ruiz-Pernía JJ, Świderek K, Bertran J, Moliner V, Tuñón I. Electrostatics as a Guiding Principle in Understanding and Designing Enzymes. J Chem Theory Comput 2024; 20:1783-1795. [PMID: 38410913 PMCID: PMC10938506 DOI: 10.1021/acs.jctc.3c01395] [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: 12/21/2023] [Revised: 02/14/2024] [Accepted: 02/14/2024] [Indexed: 02/28/2024]
Abstract
Enzyme design faces challenges related to the implementation of the basic principles that govern the catalytic activity in natural enzymes. In this work, we revisit basic electrostatic concepts that have been shown to explain the origin of enzymatic efficiency like preorganization and reorganization. Using magnitudes such as the electrostatic potential and the electric field generated by the protein, we explain how these concepts work in different enzymes and how they can be used to rationalize the consequences of point mutations. We also discuss examples of protein design in which electrostatic effects have been implemented. For the near future, molecular simulations, coupled with the use of machine learning methods, can be used to implement electrostatics as a guiding principle for enzyme designs.
Collapse
Affiliation(s)
| | - Katarzyna Świderek
- Biocomp
group, Institute of Advanced Materials (INAM), Universitat Jaume I, 12071 Castellón Spain
| | - Joan Bertran
- Departament
de Química, Universitat Autònoma
de Barcelona, 08193 Bellaterra, Spain
| | - Vicent Moliner
- Biocomp
group, Institute of Advanced Materials (INAM), Universitat Jaume I, 12071 Castellón Spain
| | - Iñaki Tuñón
- Departament
de Química Física, Universitat
de València, 46100 Burjassot, Spain
| |
Collapse
|
10
|
Fan XF, Fu L, Cui GH. Three robust Cd(II) coordination polymers as bifunctional luminescent probes for efficient detection of pefloxacin and Cr 2O 72- in water. Dalton Trans 2024; 53:5051-5063. [PMID: 38375864 DOI: 10.1039/d4dt00128a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/21/2024]
Abstract
The accurate and rapid detection of antibiotics and heavy-metal-based toxic oxo-anions in water media employing coordination polymers (CPs) as luminescent probes has attracted a lot of attention. Three new Cd(II)-based ternary CPs derived from first-presented L ligands, including [Cd(DCTP)(L)(OH)]n (1), [Cd(TBTA)(L)(OH)]n (2), and [Cd(NPHT)(L)(H2O)]n (3) (L = 2-((1H-imidazol-1-yl)methyl)-5,6-dimethyl-1H-benzo[d]imidazole, H2DCTP = 2,5-dichloroterephthalic acid, H2TBTA = tetrabromoterephthalic acid and H2NPHT = 3-nitrophthalic acid), were successfully assembled and characterized. 1 and 2 show 2D hcb layers, which can be further extended into a 3D supramolecular framework via classic hydrogen bonding interactions. 3 features a 1D double chain that ultimately spreads into a 2D network through weak hydrogen bonding interactions. With the advantages of high stability and excellent luminescent properties, the three CPs display high sensitivity, selectivity, and good anti-interference for the sensing of pefloxacin (PEF) and Cr2O72- ions (LOD values toward PEF: 3.82 × 10-7 mol L-1 for 1, 4.06 × 10-7 mol L-1 for 2, and 1.36 × 10-8 mol L-1 for 3, and toward Cr2O72- ions: 5.97 × 10-7 mol L-1 for 1, 5.87 × 10-7 mol L-1 for 2, and 8.21 × 10-8 mol L-1 for 3). These CPs are the first examples of bifunctional luminescent sensors to detect PEF and Cr2O72- in aqueous solutions. The luminescence quenching mechanisms are explored in detail.
Collapse
Affiliation(s)
- Xiao-Fei Fan
- College of Chemical Engineering, Hebei Key Laboratory for Environment Photocatalytic and Electrocatalytic Materials, North China University of Science and Technology, No. 21 Bohai Road, Caofeidian new-city, Tangshan, Hebei, 063210, P. R. China.
| | - Lianshe Fu
- Department of Physics and CICECO-Aveiro Institute of Materials, University of Aveiro, 3810-193 Aveiro, Portugal
| | - Guang-Hua Cui
- College of Chemical Engineering, Hebei Key Laboratory for Environment Photocatalytic and Electrocatalytic Materials, North China University of Science and Technology, No. 21 Bohai Road, Caofeidian new-city, Tangshan, Hebei, 063210, P. R. China.
| |
Collapse
|
11
|
Wu Y, Cui Y, Song W, Wei W, He Z, Tao J, Yin D, Chen X, Gao C, Liu J, Liu L, Wu J. Reprogramming the Transition States to Enhance C-N Cleavage Efficiency of Rhodococcus opacusl-Amino Acid Oxidase. JACS AU 2024; 4:557-569. [PMID: 38425913 PMCID: PMC10900486 DOI: 10.1021/jacsau.3c00672] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/30/2023] [Revised: 12/21/2023] [Accepted: 12/26/2023] [Indexed: 03/02/2024]
Abstract
l-Amino acid oxidase (LAAO) is an important biocatalyst used for synthesizing α-keto acids. LAAO from Rhodococcus opacus (RoLAAO) has a broad substrate spectrum; however, its low total turnover number limits its industrial use. To overcome this, we aimed to employ crystal structure-guided density functional theory calculations and molecular dynamic simulations to investigate the catalytic mechanism. Two key steps were identified: S → [TS1] in step 1 and Int1 → [TS2] in step 2. We reprogrammed the transition states [TS1] and [TS2] to reduce the identified energy barrier and obtain a RoLAAO variant capable of catalyzing 19 kinds of l-amino acids to the corresponding high-value α-keto acids with a high total turnover number, yield (≥95.1 g/L), conversion rate (≥95%), and space-time yields ≥142.7 g/L/d in 12-24 h, in a 5 L reactor. Our results indicated the promising potential of the developed RoLAAO variant for use in the industrial production of α-keto acids while providing a potential catalytic-mechanism-guided protein design strategy to achieve the desired physical and catalytic properties of enzymes.
Collapse
Affiliation(s)
- Yaoyun Wu
- School
of Life Sciences and Health Engineering, Jiangnan University, Wuxi 214122, China
- State
Key Laboratory of Food Science and Resources, Jiangnan University, Wuxi 214122, China
- School
of Biotechnology, Jiangnan University, Wuxi 214122, China
| | - Yaozhong Cui
- Jiangsu
Xishan Senior High School, Wuxi 214174, China
| | - Wei Song
- School
of Life Sciences and Health Engineering, Jiangnan University, Wuxi 214122, China
| | - Wanqing Wei
- State
Key Laboratory of Food Science and Resources, Jiangnan University, Wuxi 214122, China
| | - Zhizhen He
- School
of Life Sciences and Health Engineering, Jiangnan University, Wuxi 214122, China
| | - Jinyang Tao
- School
of Life Sciences and Health Engineering, Jiangnan University, Wuxi 214122, China
| | - Dejing Yin
- School
of Biotechnology, Jiangnan University, Wuxi 214122, China
| | - Xiulai Chen
- State
Key Laboratory of Food Science and Resources, Jiangnan University, Wuxi 214122, China
| | - Cong Gao
- State
Key Laboratory of Food Science and Resources, Jiangnan University, Wuxi 214122, China
| | - Jia Liu
- State
Key Laboratory of Food Science and Resources, Jiangnan University, Wuxi 214122, China
| | - Liming Liu
- State
Key Laboratory of Food Science and Resources, Jiangnan University, Wuxi 214122, China
| | - Jing Wu
- School
of Life Sciences and Health Engineering, Jiangnan University, Wuxi 214122, China
| |
Collapse
|
12
|
Cui Y, Chen Y, Sun J, Zhu T, Pang H, Li C, Geng WC, Wu B. Computational redesign of a hydrolase for nearly complete PET depolymerization at industrially relevant high-solids loading. Nat Commun 2024; 15:1417. [PMID: 38360963 PMCID: PMC10869840 DOI: 10.1038/s41467-024-45662-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2023] [Accepted: 01/30/2024] [Indexed: 02/17/2024] Open
Abstract
Biotechnological plastic recycling has emerged as a suitable option for addressing the pollution crisis. A major breakthrough in the biodegradation of poly(ethylene terephthalate) (PET) is achieved by using a LCC variant, which permits 90% conversion at an industrial level. Despite the achievements, its applications have been hampered by the remaining 10% of nonbiodegradable PET. Herein, we address current challenges by employing a computational strategy to engineer a hydrolase from the bacterium HR29. The redesigned variant, TurboPETase, outperforms other well-known PET hydrolases. Nearly complete depolymerization is accomplished in 8 h at a solids loading of 200 g kg-1. Kinetic and structural analysis suggest that the improved performance may be attributed to a more flexible PET-binding groove that facilitates the targeting of more specific attack sites. Collectively, our results constitute a significant advance in understanding and engineering of industrially applicable polyester hydrolases, and provide guidance for further efforts on other polymer types.
Collapse
Affiliation(s)
- Yinglu Cui
- AIM Center, Institute of Microbiology, Chinese Academy of Sciences, Beijing, China.
| | - Yanchun Chen
- AIM Center, Institute of Microbiology, Chinese Academy of Sciences, Beijing, China
| | - Jinyuan Sun
- AIM Center, Institute of Microbiology, Chinese Academy of Sciences, Beijing, China
- University of Chinese Academy of Sciences, Beijing, China
| | - Tong Zhu
- AIM Center, Institute of Microbiology, Chinese Academy of Sciences, Beijing, China
| | - Hua Pang
- AIM Center, Institute of Microbiology, Chinese Academy of Sciences, Beijing, China
| | - Chunli Li
- AIM Center, Institute of Microbiology, Chinese Academy of Sciences, Beijing, China
| | - Wen-Chao Geng
- AIM Center, Institute of Microbiology, Chinese Academy of Sciences, Beijing, China
- College of Chemistry, Nankai University, Tianjin, China
| | - Bian Wu
- AIM Center, Institute of Microbiology, Chinese Academy of Sciences, Beijing, China.
| |
Collapse
|
13
|
Zhou X, Zhou X, Xu Z, Zhang M, Zhu H. Characterization and engineering of plastic-degrading polyesterases jmPE13 and jmPE14 from Pseudomonas bacterium. Front Bioeng Biotechnol 2024; 12:1349010. [PMID: 38425995 PMCID: PMC10904013 DOI: 10.3389/fbioe.2024.1349010] [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: 12/04/2023] [Accepted: 01/31/2024] [Indexed: 03/02/2024] Open
Abstract
Polyester plastics are widely used in daily life, but also cause a large amount of waste. Degradation by microbial enzymes is the most promising way for the biobased upcycling of the wastes. However, there is still a shortage of high-performance enzymes, and more efficient polyester hydrolases need to be developed. Here we identified two polyester hydrolases, jmPE13 and jmPE14, from a previously isolated strain Pseudomonas sp. JM16B3. The proteins were recombinantly expressed and purified in E. coli, and their enzymatic properties were characterized. JmPE13 and jmPE14 showed hydrolytic activity towards polyethylene terephthalate (PET) and Poly (butylene adipate-co-terephthalate) (PBAT) at medium temperatures. The enzyme activity and stability of jmPE13 were further improved to 3- and 1.5-fold, respectively, by rational design. The results of our research can be helpful for further engineering of more efficient polyester plastic hydrolases and their industrial applications.
Collapse
Affiliation(s)
| | | | | | | | - Honghui Zhu
- Key Laboratory of Agricultural Microbiomics and Precision Application (MARA), Key Laboratory of Agricultural Microbiome (MARA), Guangdong Provincial Key Laboratory of Microbial Culture Collection and Application, State Key Laboratory of Applied Microbiology Southern China, Institute of Microbiology, Guangdong Academy of Sciences, Guangzhou, China
| |
Collapse
|
14
|
Bell EL, Rosetto G, Ingraham MA, Ramirez KJ, Lincoln C, Clarke RW, Gado JE, Lilly JL, Kucharzyk KH, Erickson E, Beckham GT. Natural diversity screening, assay development, and characterization of nylon-6 enzymatic depolymerization. Nat Commun 2024; 15:1217. [PMID: 38336849 PMCID: PMC10858056 DOI: 10.1038/s41467-024-45523-5] [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: 09/10/2023] [Accepted: 01/24/2024] [Indexed: 02/12/2024] Open
Abstract
Successes in biocatalytic polyester recycling have raised the possibility of deconstructing alternative polymers enzymatically, with polyamide (PA) being a logical target due to the array of amide-cleaving enzymes present in nature. Here, we screen 40 potential natural and engineered nylon-hydrolyzing enzymes (nylonases), using mass spectrometry to quantify eight compounds resulting from enzymatic nylon-6 (PA6) hydrolysis. Comparative time-course reactions incubated at 40-70 °C showcase enzyme-dependent variations in product distributions and extent of PA6 film depolymerization, with significant nylon deconstruction activity appearing rare. The most active nylonase, a NylCK variant we rationally thermostabilized (an N-terminal nucleophile (Ntn) hydrolase, NylCK-TS, Tm = 87.4 °C, 16.4 °C higher than the wild-type), hydrolyzes 0.67 wt% of a PA6 film. Reactions fail to restart after fresh enzyme addition, indicating that substrate-based limitations, such as restricted enzyme access to hydrolysable bonds, prohibit more extensive deconstruction. Overall, this study expands our understanding of nylonase activity distribution, indicates that Ntn hydrolases may have the greatest potential for further development, and identifies key targets for progressing PA6 enzymatic depolymerization, including improving enzyme activity, product selectivity, and enhancing polymer accessibility.
Collapse
Affiliation(s)
- Elizabeth L Bell
- Renewable Resources and Enabling Sciences Center, National Renewable Energy Laboratory, Golden, CO, 80401, USA
- BOTTLE Consortium, Golden, CO, 80401, USA
| | - Gloria Rosetto
- Renewable Resources and Enabling Sciences Center, National Renewable Energy Laboratory, Golden, CO, 80401, USA
| | - Morgan A Ingraham
- Renewable Resources and Enabling Sciences Center, National Renewable Energy Laboratory, Golden, CO, 80401, USA
- BOTTLE Consortium, Golden, CO, 80401, USA
| | - Kelsey J Ramirez
- Renewable Resources and Enabling Sciences Center, National Renewable Energy Laboratory, Golden, CO, 80401, USA
- BOTTLE Consortium, Golden, CO, 80401, USA
| | - Clarissa Lincoln
- Renewable Resources and Enabling Sciences Center, National Renewable Energy Laboratory, Golden, CO, 80401, USA
- BOTTLE Consortium, Golden, CO, 80401, USA
| | - Ryan W Clarke
- Renewable Resources and Enabling Sciences Center, National Renewable Energy Laboratory, Golden, CO, 80401, USA
- BOTTLE Consortium, Golden, CO, 80401, USA
| | - Japheth E Gado
- Renewable Resources and Enabling Sciences Center, National Renewable Energy Laboratory, Golden, CO, 80401, USA
- BOTTLE Consortium, Golden, CO, 80401, USA
| | - Jacob L Lilly
- Battelle Memorial Institute, Columbus, OH, 43201, USA
| | | | - Erika Erickson
- Renewable Resources and Enabling Sciences Center, National Renewable Energy Laboratory, Golden, CO, 80401, USA
- BOTTLE Consortium, Golden, CO, 80401, USA
| | - Gregg T Beckham
- Renewable Resources and Enabling Sciences Center, National Renewable Energy Laboratory, Golden, CO, 80401, USA.
- BOTTLE Consortium, Golden, CO, 80401, USA.
| |
Collapse
|
15
|
Amalia L, Chang CY, Wang SSS, Yeh YC, Tsai SL. Recent advances in the biological depolymerization and upcycling of polyethylene terephthalate. Curr Opin Biotechnol 2024; 85:103053. [PMID: 38128200 DOI: 10.1016/j.copbio.2023.103053] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2023] [Revised: 11/16/2023] [Accepted: 11/28/2023] [Indexed: 12/23/2023]
Abstract
Polyethylene terephthalate (PET) is favored for its exceptional properties and widespread daily use. This review highlights recent advancements that enable the development of biological tools for PET decomposition, transforming PET into valuable platform chemicals and materials in upcycling processes. Enhancing PET hydrolases' catalytic activity and efficiency through protein engineering strategies is a priority, facilitating more effective PET waste management. Efforts to create novel PET hydrolases for large-scale PET depolymerization continue, but cost-effectiveness remains challenging. Hydrolyzed monomers must add additional value to make PET recycling economically attractive. Valorization of hydrolysis products through the upcycling process is expected to produce new compounds with different values and qualities from the initial polymer, making the decomposed monomers more appealing. Advances in synthetic biology and enzyme engineering hold promise for PET upcycling. While biological depolymerization offers environmental benefits, further research is needed to make PET upcycling sustainable and economically feasible.
Collapse
Affiliation(s)
- Lita Amalia
- Department of Chemical Engineering, National Taiwan University of Science and Technology, Taipei 10607, Taiwan
| | - Chia-Yu Chang
- Department of Chemical Engineering, National Taiwan University, Taipei 10617, Taiwan
| | - Steven S-S Wang
- Department of Chemical Engineering, National Taiwan University, Taipei 10617, Taiwan
| | - Yi-Chun Yeh
- Department of Chemistry, National Taiwan Normal University, Taipei 11677, Taiwan
| | - Shen-Long Tsai
- Department of Chemical Engineering, National Taiwan University of Science and Technology, Taipei 10607, Taiwan.
| |
Collapse
|
16
|
Joho Y, Vongsouthi V, Gomez C, Larsen JS, Ardevol A, Jackson CJ. Improving plastic degrading enzymes via directed evolution. Protein Eng Des Sel 2024; 37:gzae009. [PMID: 38713696 PMCID: PMC11091475 DOI: 10.1093/protein/gzae009] [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: 12/15/2023] [Revised: 04/30/2024] [Accepted: 05/05/2024] [Indexed: 05/09/2024] Open
Abstract
Plastic degrading enzymes have immense potential for use in industrial applications. Protein engineering efforts over the last decade have resulted in considerable enhancement of many properties of these enzymes. Directed evolution, a protein engineering approach that mimics the natural process of evolution in a laboratory, has been particularly useful in overcoming some of the challenges of structure-based protein engineering. For example, directed evolution has been used to improve the catalytic activity and thermostability of polyethylene terephthalate (PET)-degrading enzymes, although its use for the improvement of other desirable properties, such as solvent tolerance, has been less studied. In this review, we aim to identify some of the knowledge gaps and current challenges, and highlight recent studies related to the directed evolution of plastic-degrading enzymes.
Collapse
Affiliation(s)
- Yvonne Joho
- Manufacturing, Commonwealth Scientific and Industrial Research Organisation, Research Way, Clayton, Victoria 3168, Australia
- Research School of Chemistry, Australian National University, Sullivans Creek Rd, Canberra, ACT 2601, Australia
- CSIRO Advanced Engineering Biology Future Science Platform, GPO Box 1700, Canberra, ACT 2601, Australia
| | - Vanessa Vongsouthi
- Research School of Chemistry, Australian National University, Sullivans Creek Rd, Canberra, ACT 2601, Australia
| | - Chloe Gomez
- Research School of Chemistry, Australian National University, Sullivans Creek Rd, Canberra, ACT 2601, Australia
| | - Joachim S Larsen
- Research School of Chemistry, Australian National University, Sullivans Creek Rd, Canberra, ACT 2601, Australia
- ARC Centre of Excellence for Synthetic Biology, Research School of Chemistry, Australian National University, Sullivans Creek Rd, Canberra, ACT 2601, Australia
| | - Albert Ardevol
- Manufacturing, Commonwealth Scientific and Industrial Research Organisation, Research Way, Clayton, Victoria 3168, Australia
- CSIRO Advanced Engineering Biology Future Science Platform, GPO Box 1700, Canberra, ACT 2601, Australia
| | - Colin J Jackson
- Research School of Chemistry, Australian National University, Sullivans Creek Rd, Canberra, ACT 2601, Australia
- ARC Centre of Excellence for Synthetic Biology, Research School of Chemistry, Australian National University, Sullivans Creek Rd, Canberra, ACT 2601, Australia
- ARC Centre of Excellence for Innovations in Peptide & Protein Science, Research School of Chemistry, Australian National University, Sullivans Creek Rd, Canberra, ACT 2601, Australia
| |
Collapse
|
17
|
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.
Collapse
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
| |
Collapse
|
18
|
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.
Collapse
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
| |
Collapse
|
19
|
Xue R, Qiu C, Zhou X, Cheng Y, Zhang Z, Zhang Y, Schröder U, Bornscheuer UT, Dong W, Wei R, Jiang M. Enzymatic Upcycling of PET Waste to Calcium Terephthalate for Battery Anodes. Angew Chem Int Ed Engl 2024; 63:e202313633. [PMID: 37880836 DOI: 10.1002/anie.202313633] [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: 09/13/2023] [Revised: 10/23/2023] [Accepted: 10/25/2023] [Indexed: 10/27/2023]
Abstract
Biotechnological recycling offers a promising solution to address the environmental concerns associated with waste plastics, particularly polyethylene terephthalate (PET), widely utilized in packaging materials and textiles. To advance the development of a bio-based circular plastic economy, innovative upcycling strategies capable of generating higher-value products are needed. In this study, we enhanced the enzymatic depolymerization of waste PET by incorporating highly concentrated calcium ions (up to 1 m) to the hydrolytic reaction catalyzed by the best currently known enzyme LCCICCG . The presence of calcium ions not only improved the thermal stability and activity of the biocatalyst but also significantly reduced the consumption of base required to maintain optimal pH levels. Employing optimized conditions at 80 °C for 12 h, we successfully converted ≈84 % of the waste PET (200 g L-1 ) into solid hydrated calcium terephthalate (CaTP ⋅ 3H2 O) as the primary product instead of soluble terephthalate salt. CaTP ⋅ 3H2 O was easily purified and employed as a raw material for battery electrode production, exhibiting an initial reversible specific capacity of 164.2 mAh g-1 . Through techno-economic analysis, we conclusively demonstrated that the one-pot biocatalysis-based synthesis of CaTP is a superior PET upcycling strategy than the secondary synthesis method employing recycled terephthalic acid.
Collapse
Affiliation(s)
- Rui Xue
- College of Biotechnology and Pharmaceutical Engineering, State Key Laboratory of Materials-Oriented Chemical Engineering, Nanjing Tech University, Nanjing, 211816, P. R. China
| | - Canhao Qiu
- College of Biotechnology and Pharmaceutical Engineering, State Key Laboratory of Materials-Oriented Chemical Engineering, Nanjing Tech University, Nanjing, 211816, P. R. China
| | - Xiaoli Zhou
- College of Biotechnology and Pharmaceutical Engineering, State Key Laboratory of Materials-Oriented Chemical Engineering, Nanjing Tech University, Nanjing, 211816, P. R. China
| | - Yun Cheng
- College of Biotechnology and Pharmaceutical Engineering, State Key Laboratory of Materials-Oriented Chemical Engineering, Nanjing Tech University, Nanjing, 211816, P. R. China
| | - Zhen Zhang
- School of Energy Science and Engineering, Nanjing Tech University, Nanjing, 211816, P. R. China
| | - Yi Zhang
- School of Energy Science and Engineering, Nanjing Tech University, Nanjing, 211816, P. R. China
| | - Uwe Schröder
- Institute of Biochemistry, University of Greifswald, Felix-Hausdorff-Str. 4, 17487, Greifswald, Germany
| | - Uwe T Bornscheuer
- Institute of Biochemistry, University of Greifswald, Felix-Hausdorff-Str. 4, 17487, Greifswald, Germany
| | - Weiliang Dong
- College of Biotechnology and Pharmaceutical Engineering, State Key Laboratory of Materials-Oriented Chemical Engineering, Nanjing Tech University, Nanjing, 211816, P. R. China
| | - Ren Wei
- Institute of Biochemistry, University of Greifswald, Felix-Hausdorff-Str. 4, 17487, Greifswald, Germany
| | - Min Jiang
- College of Biotechnology and Pharmaceutical Engineering, State Key Laboratory of Materials-Oriented Chemical Engineering, Nanjing Tech University, Nanjing, 211816, P. R. China
| |
Collapse
|
20
|
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.
Collapse
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
| |
Collapse
|
21
|
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.
Collapse
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
| |
Collapse
|
22
|
Thomsen TB, Almdal K, Meyer AS. Significance of poly(ethylene terephthalate) (PET) substrate crystallinity on enzymatic degradation. N Biotechnol 2023; 78:162-172. [PMID: 37939899 DOI: 10.1016/j.nbt.2023.11.001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2023] [Revised: 10/20/2023] [Accepted: 11/04/2023] [Indexed: 11/10/2023]
Abstract
Poly(ethylene terephthalate) (PET) is a semi-crystalline plastic polyester material with a global production volume of 83 Mt/year. PET is mainly used in textiles, but also widely used for packaging materials, notably plastic bottles, and is a major contributor to environmental plastic waste accumulation. Now that enzymes have been demonstrated to catalyze PET degradation, new options for sustainable bio-recycling of PET materials via enzymatic catalysis have emerged. The enzymatic degradation rate is strongly influenced by the properties of PET, notably the degree of crystallinity, XC. The higher the XC of the PET material, the slower the enzymatic rate. Crystallization of PET, resulting in increased XC, is induced thermally (via heating) and/or mechanically (via stretching), and the XC of most PET plastic bottles and microplastics exceeds what currently known enzymes can readily degrade. The enzymatic action occurs at the surface of the insoluble PET material and improves when the polyester chain mobility increases. The chain mobility increases drastically when the temperature exceeds the glass transition temperature, Tg, which is ∼40 °C at the surface layer of PET. Since PET crystallization starts at 70 °C, the ideal temperature for enzymatic degradation is just below 70 °C to balance high chain mobility and enzymatic reaction activation without inducing crystal formation. This paper reviews the current understanding on the properties of PET as an enzyme substrate and summarizes the most recent knowledge of how the crystalline and amorphous regions of PET form, and how the XC and the Tg impact the efficiency of enzymatic PET degradation.
Collapse
Affiliation(s)
- Thore Bach Thomsen
- Department of Biotechnology and Biomedicine, DTU Bioengineering, Protein Chemistry and Enzyme Technology Section, Building 221, Technical University of Denmark, 2800 Kgs Lyngby, Denmark
| | - Kristoffer Almdal
- DTU Chemistry, Building 206, Technical University of Denmark, 2800 Kgs Lyngby, Denmark
| | - Anne S Meyer
- Department of Biotechnology and Biomedicine, DTU Bioengineering, Protein Chemistry and Enzyme Technology Section, Building 221, Technical University of Denmark, 2800 Kgs Lyngby, Denmark.
| |
Collapse
|
23
|
Cao Z, Xia W, Wu S, Ma J, Zhou X, Qian X, Xu A, Dong W, Jiang M. Bioengineering Comamonas testosteroni CNB-1: a robust whole-cell biocatalyst for efficient PET microplastic degradation. BIORESOUR BIOPROCESS 2023; 10:94. [PMID: 38647778 PMCID: PMC10992048 DOI: 10.1186/s40643-023-00715-7] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2023] [Accepted: 12/10/2023] [Indexed: 04/25/2024] Open
Abstract
The escalating crisis of polyethylene terephthalate (PET) microplastic contamination in biological wastewater treatment systems is a pressing environmental concern. These microplastics inevitably accumulate in sewage sludge due to the absence of effective removal technologies. Addressing this urgent issue, this study introduces a novel approach using DuraPETase, a potent enzyme with enhanced PET hydrolytic activity at ambient temperatures. Remarkably, this enzyme was successfully secreted from Comamonas testosteroni CNB-1, a dominant species in the active sludge. The secreted DuraPETase showed significant hydrolytic activity toward p-NPB and PET nanoplastics. Furthermore, the CNB-1 derived whole-cell biocatalyst was able to depolymerize PET microplastics under ambient temperature, achieving a degradation efficiency of 9% within 7 days. The CNB-1-based whole biocatalysts were also capable of utilizing PET degradation intermediates, such as terephthalic acid (TPA) and ethylene glycol (EG), and bis(2-hydroxyethyl)-TPA (BHET), for growth. This indicates that it can completely mineralize PET, as opposed to merely breaking it down into smaller molecules. This research highlights the potential of activated sludge as a potent source for insitu microplastic removal.
Collapse
Affiliation(s)
- Zhanqing Cao
- College of Biotechnology and Pharmaceutical Engineering, Nanjing Tech University, Nanjing, 211816, China
| | - Wei Xia
- College of Biotechnology and Pharmaceutical Engineering, Nanjing Tech University, Nanjing, 211816, China
| | - Shilei Wu
- College of Biotechnology and Pharmaceutical Engineering, Nanjing Tech University, Nanjing, 211816, China
| | - Jiale Ma
- College of Biotechnology and Pharmaceutical Engineering, Nanjing Tech University, Nanjing, 211816, China
| | - Xiaoli Zhou
- College of Biotechnology and Pharmaceutical Engineering, Nanjing Tech University, Nanjing, 211816, China
| | - Xiujuan Qian
- College of Biotechnology and Pharmaceutical Engineering, Nanjing Tech University, Nanjing, 211816, China
| | - Anming Xu
- College of Biotechnology and Pharmaceutical Engineering, Nanjing Tech University, Nanjing, 211816, China.
| | - Weiliang Dong
- College of Biotechnology and Pharmaceutical Engineering, Nanjing Tech University, Nanjing, 211816, China.
- State Key Laboratory of Materials-Oriented Chemical Engineering, Nanjing Tech University, Nanjing, 211816, China.
- Key Laboratory for Waste Plastics Biocatalytic Degradation and Recycling, Nanjing Tech University, Nanjing, 211816, China.
| | - Min Jiang
- College of Biotechnology and Pharmaceutical Engineering, Nanjing Tech University, Nanjing, 211816, China
- State Key Laboratory of Materials-Oriented Chemical Engineering, Nanjing Tech University, Nanjing, 211816, China
- Key Laboratory for Waste Plastics Biocatalytic Degradation and Recycling, Nanjing Tech University, Nanjing, 211816, China
| |
Collapse
|
24
|
Soong YHV, Abid U, Chang AC, Ayafor C, Patel A, Qin J, Xu J, Lawton C, Wong HW, Sobkowicz MJ, Xie D. Enzyme selection, optimization, and production toward biodegradation of post-consumer poly(ethylene terephthalate) at scale. Biotechnol J 2023; 18:e2300119. [PMID: 37594123 DOI: 10.1002/biot.202300119] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2023] [Revised: 08/07/2023] [Accepted: 08/11/2023] [Indexed: 08/19/2023]
Abstract
Poly(ethylene terephthalate) (PET) is one of the world's most widely used polyester plastics. Due to its chemical stability, PET is extremely difficult to hydrolyze in a natural environment. Recent discoveries in new polyester hydrolases and breakthroughs in enzyme engineering strategies have inspired enormous research on biorecycling of PET. This study summarizes our research efforts toward large-scale, efficient, and economical biodegradation of post-consumer waste PET, including PET hydrolase selection and optimization, high-yield enzyme production, and high-capacity enzymatic degradation of post-consumer waste PET. First, genes encoding PETase and MHETase from Ideonella sakaiensis and the ICCG variant of leaf-branch compost cutinase (LCCICCG ) were codon-optimized and expressed in Escherichia coli BL21(DE3) for high-yield production. To further lower the enzyme production cost, a pelB leader sequence was fused to LCCICCG so that the enzyme can be secreted into the medium to facilitate recovery. To help bind the enzyme on the hydrophobic surface of PET, a substrate-binding module in a polyhydroxyalkanoate depolymerase from Alcaligenes faecalis (PBM) was fused to the C-terminus of LCCICCG . The resulting four different LCCICCG variants (LCC, PelB-LCC, LCC-PBM, and PelB-LCC-PBM), together with PETase and MHETase, were compared for PET degradation efficiency. A fed-batch fermentation process was developed to produce the target enzymes up to 1.2 g L-1 . Finally, the best enzyme, PelB-LCC, was selected and used for the efficient degradation of 200 g L-1 recycled PET in a well-controlled, stirred-tank reactor. The results will help develop an economical and scalable biorecycling process toward a circular PET economy.
Collapse
Affiliation(s)
- Ya-Hue Valerie Soong
- Department of Chemical Engineering, University of Massachusetts Lowell, Lowell, Massachusetts, USA
| | - Umer Abid
- Department of Chemical Engineering, University of Massachusetts Lowell, Lowell, Massachusetts, USA
| | - Allen C Chang
- Department of Plastics Engineering, University of Massachusetts Lowell, Lowell, Massachusetts, USA
| | - Christian Ayafor
- Energy Engineering Program, University of Massachusetts Lowell, Lowell, Massachusetts, USA
| | - Akanksha Patel
- Department of Plastics Engineering, University of Massachusetts Lowell, Lowell, Massachusetts, USA
| | - Jiansong Qin
- Department of Chemical Engineering, University of Massachusetts Lowell, Lowell, Massachusetts, USA
| | - Jin Xu
- Department of Chemistry, University of Massachusetts Lowell, Lowell, Massachusetts, USA
| | - Carl Lawton
- Department of Chemical Engineering, University of Massachusetts Lowell, Lowell, Massachusetts, USA
| | - Hsi-Wu Wong
- Department of Chemical Engineering, University of Massachusetts Lowell, Lowell, Massachusetts, USA
| | - Margaret J Sobkowicz
- Department of Plastics Engineering, University of Massachusetts Lowell, Lowell, Massachusetts, USA
| | - Dongming Xie
- Department of Chemical Engineering, University of Massachusetts Lowell, Lowell, Massachusetts, USA
| |
Collapse
|
25
|
Zhang J, Wang H, Luo Z, Yang Z, Zhang Z, Wang P, Li M, Zhang Y, Feng Y, Lu D, Zhu Y. Computational design of highly efficient thermostable MHET hydrolases and dual enzyme system for PET recycling. Commun Biol 2023; 6:1135. [PMID: 37945666 PMCID: PMC10636135 DOI: 10.1038/s42003-023-05523-5] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2023] [Accepted: 10/30/2023] [Indexed: 11/12/2023] Open
Abstract
Recently developed enzymes for the depolymerization of polyethylene terephthalate (PET) such as FAST-PETase and LCC-ICCG are inhibited by the intermediate PET product mono(2-hydroxyethyl) terephthalate (MHET). Consequently, the conversion of PET enzymatically into its constituent monomers terephthalic acid (TPA) and ethylene glycol (EG) is inefficient. In this study, a protein scaffold (1TQH) corresponding to a thermophilic carboxylesterase (Est30) was selected from the structural database and redesigned in silico. Among designs, a double variant KL-MHETase (I171K/G130L) with a similar protein melting temperature (67.58 °C) to that of the PET hydrolase FAST-PETase (67.80 °C) exhibited a 67-fold higher activity for MHET hydrolysis than FAST-PETase. A fused dual enzyme system comprising KL-MHETase and FAST-PETase exhibited a 2.6-fold faster PET depolymerization rate than FAST-PETase alone. Synergy increased the yield of TPA by 1.64 fold, and its purity in the released aromatic products reached 99.5%. In large reaction systems with 100 g/L substrate concentrations, the dual enzyme system KL36F achieved over 90% PET depolymerization into monomers, demonstrating its potential applicability in the industrial recycling of PET plastics. Therefore, a dual enzyme system can greatly reduce the reaction and separation cost for sustainable enzymatic PET recycling.
Collapse
Affiliation(s)
- Jun Zhang
- College of Life Science and Technology, Beijing University of Chemical Technology, Beijing, 100029, China
- Department of Chemical Engineering, Tsinghua University, Beijing, 100084, China
| | - Hongzhao Wang
- College of Life Science and Technology, Beijing University of Chemical Technology, Beijing, 100029, China
| | - Zhaorong Luo
- Beijing Advanced Innovation Center for Soft Matter Science and Engineering, State Key Laboratory of Chemical Resource Engineering, Beijing University of Chemical Technology, Beijing, 100029, China
| | - Zhenwu Yang
- College of Life Science and Technology, Beijing University of Chemical Technology, Beijing, 100029, China
| | - Zixuan Zhang
- College of Life Science and Technology, Beijing University of Chemical Technology, Beijing, 100029, China
| | - Pengyu Wang
- Department of Chemical Engineering, Tsinghua University, Beijing, 100084, China
| | - Mengyu Li
- College of Life Science and Technology, Beijing University of Chemical Technology, Beijing, 100029, China
| | - Yi Zhang
- Beijing Advanced Innovation Center for Soft Matter Science and Engineering, State Key Laboratory of Chemical Resource Engineering, Beijing University of Chemical Technology, Beijing, 100029, China
| | - Yue Feng
- Beijing Advanced Innovation Center for Soft Matter Science and Engineering, State Key Laboratory of Chemical Resource Engineering, Beijing University of Chemical Technology, Beijing, 100029, China
| | - Diannan Lu
- Department of Chemical Engineering, Tsinghua University, Beijing, 100084, China.
| | - Yushan Zhu
- College of Life Science and Technology, Beijing University of Chemical Technology, Beijing, 100029, China.
- National Energy R&D Center for Biorefinery, Beijing University of Chemical Technology, Beijing, 100029, China.
| |
Collapse
|
26
|
Giri PK, Samanta SS, Mudi N, Mandal U, Misra A. Synthesis of Fluorophore Based Functional Material for Selective Detection of Al 3+ Ion in Water and Decoding the AIEE Property of Its Hydrosol. J Fluoresc 2023; 33:2131-2144. [PMID: 37060429 DOI: 10.1007/s10895-023-03238-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2023] [Accepted: 04/03/2023] [Indexed: 04/16/2023]
Abstract
A designed aggregation-induced emission enhancement (AIEE) active fluorescence probe 2,3-Bis-[(2-hydroxy-napthalen-1-ylmethylene)-amino]-but-2-enedinitrile (L) was synthesized via one step condensation method. The probe shows swift sensitivity and selectivity toward Al3+over other relevant metal ions and also exhibits significant AIEE phenomena in methanol/water mixture. Significant enhancement of fluorescence intensity is triggered via chelation-enhanced fluorescence through complex (Al3+-L) formation. A 2:1 metal to ligand ratio is observed from Job's plot based on UV - Vis absorption titration and detection limit (LOD) is found as low as 31.14 nM. Moreover, 1H NMR titrations and fluorescence reversibility by adding Al3+ and EDTA sequentially had been performed to establish the binding site of sensor complex (Al3+-L). Time-resolved photoluminescence, dynamic light scattering, optical microscopy, and on-site visualization studies have been performed to understand the AIEE mechanism of L in different volume percentage of water and methanol mixture. An INHIBIT molecular logic gate has been constructed utilizing the fluorescence behavior of the probe, L in presence of Al3+ and strong chelating ligand EDTA.
Collapse
Affiliation(s)
- Prabhat Kumar Giri
- Department of Chemistry, Vidyasagar University, Midnapore, 721102, West Bengal, India
| | | | - Naren Mudi
- Department of Chemistry, Vidyasagar University, Midnapore, 721102, West Bengal, India
| | - Usha Mandal
- Department of Chemistry, Vidyasagar University, Midnapore, 721102, West Bengal, India
| | - Ajay Misra
- Department of Chemistry, Vidyasagar University, Midnapore, 721102, West Bengal, India.
| |
Collapse
|
27
|
Lu Y, Hintzen KW, Kurkina T, Ji Y, Schwaneberg U. Directed Evolution of Material Binding Peptide for Polylactic Acid-specific Degradation in Mixed Plastic Wastes. ACS Catal 2023; 13:12746-12754. [PMID: 37822861 PMCID: PMC10564037 DOI: 10.1021/acscatal.3c02142] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2023] [Revised: 08/08/2023] [Indexed: 10/13/2023]
Abstract
In order to preserve our livelihood for future generations, responsible use of plastics in a climate-neutral and circular economy has to be developed so that plastics can be used in an environmentally friendly way by future generations. The prerequisite is that bioplastic polymers such as polylactic acid (PLA) can be efficiently recycled from petrochemical based plastic. Here, a concept in which accelerated PLA degradation in the mixed suspension of PLA and polystyrene (PS) nanoparticles has been achieved through an engineered material binding peptide. After comparison of twenty material binding peptides, Cg-Def is selected due to its PLA binding specificity. Finally, a suitable high-throughput screening system is developed for enhancing material-specific binding toward PLA in presence of PS. Through KnowVolution campaign, a variant Cg-Def YH (L9Y/S19H) with 2.0-fold improved PLA binding specificity compared to PS is generated. Contact angle and surface plasmon resonance measurements validated higher surface coverage of Cg-Def YH on PLA surface and the fusion of Cg-Def YH with PLA degrading enzyme confirmed the accelerated PLA depolymerization (two times higher than only enzyme) in mixed PLA/PS plastics.
Collapse
Affiliation(s)
- Yi Lu
- Institute
of Biotechnology, RWTH Aachen University, Aachen 52074, Germany
| | - Kai-Wolfgang Hintzen
- Institute
of Biotechnology, RWTH Aachen University, Aachen 52074, Germany
- DWI-Leibniz
Institute for Interactive Materials, Aachen 52074, Germany
| | - Tetiana Kurkina
- Institute
of Biotechnology, RWTH Aachen University, Aachen 52074, Germany
| | - Yu Ji
- Institute
of Biotechnology, RWTH Aachen University, Aachen 52074, Germany
| | - Ulrich Schwaneberg
- Institute
of Biotechnology, RWTH Aachen University, Aachen 52074, Germany
- DWI-Leibniz
Institute for Interactive Materials, Aachen 52074, Germany
| |
Collapse
|
28
|
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.
Collapse
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
| |
Collapse
|
29
|
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: 4] [Impact Index Per Article: 4.0] [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.
Collapse
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.
| |
Collapse
|
30
|
Williams GB, Ma H, Khusnutdinova AN, Yakunin AF, Golyshin PN. Harnessing extremophilic carboxylesterases for applications in polyester depolymerisation and plastic waste recycling. Essays Biochem 2023; 67:715-729. [PMID: 37334661 PMCID: PMC10423841 DOI: 10.1042/ebc20220255] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2023] [Revised: 06/01/2023] [Accepted: 06/05/2023] [Indexed: 06/20/2023]
Abstract
The steady growth in industrial production of synthetic plastics and their limited recycling have resulted in severe environmental pollution and contribute to global warming and oil depletion. Currently, there is an urgent need to develop efficient plastic recycling technologies to prevent further environmental pollution and recover chemical feedstocks for polymer re-synthesis and upcycling in a circular economy. Enzymatic depolymerization of synthetic polyesters by microbial carboxylesterases provides an attractive addition to existing mechanical and chemical recycling technologies due to enzyme specificity, low energy consumption, and mild reaction conditions. Carboxylesterases constitute a diverse group of serine-dependent hydrolases catalysing the cleavage and formation of ester bonds. However, the stability and hydrolytic activity of identified natural esterases towards synthetic polyesters are usually insufficient for applications in industrial polyester recycling. This necessitates further efforts on the discovery of robust enzymes, as well as protein engineering of natural enzymes for enhanced activity and stability. In this essay, we discuss the current knowledge of microbial carboxylesterases that degrade polyesters (polyesterases) with focus on polyethylene terephthalate (PET), which is one of the five major synthetic polymers. Then, we briefly review the recent progress in the discovery and protein engineering of microbial polyesterases, as well as developing enzyme cocktails and secreted protein expression for applications in the depolymerisation of polyester blends and mixed plastics. Future research aimed at the discovery of novel polyesterases from extreme environments and protein engineering for improved performance will aid developing efficient polyester recycling technologies for the circular plastics economy.
Collapse
Affiliation(s)
- Gwion B Williams
- Centre for Environmental Biotechnology, School of Natural Sciences, Bangor University, Deiniol Road, Bangor LL57 2UW, U.K
| | - Hairong Ma
- Centre for Environmental Biotechnology, School of Natural Sciences, Bangor University, Deiniol Road, Bangor LL57 2UW, U.K
| | - Anna N Khusnutdinova
- Centre for Environmental Biotechnology, School of Natural Sciences, Bangor University, Deiniol Road, Bangor LL57 2UW, U.K
| | - Alexander F Yakunin
- Centre for Environmental Biotechnology, School of Natural Sciences, Bangor University, Deiniol Road, Bangor LL57 2UW, U.K
| | - Peter N Golyshin
- Centre for Environmental Biotechnology, School of Natural Sciences, Bangor University, Deiniol Road, Bangor LL57 2UW, U.K
| |
Collapse
|
31
|
Ding Z, Xu G, Miao R, Wu N, Zhang W, Yao B, Guan F, Huang H, Tian J. Rational redesign of thermophilic PET hydrolase LCCICCG to enhance hydrolysis of high crystallinity polyethylene terephthalates. JOURNAL OF HAZARDOUS MATERIALS 2023; 453:131386. [PMID: 37043849 DOI: 10.1016/j.jhazmat.2023.131386] [Citation(s) in RCA: 8] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/18/2023] [Revised: 03/11/2023] [Accepted: 04/06/2023] [Indexed: 05/03/2023]
Abstract
Polyethylene terephthalate (PET)-degrading enzymes represent a promising solution to the plastic pollution. However, PET-degrading enzymes, even thermophilic PETase, can effectively degrade low-crystallinity (∼8%) PETs, but exhibit weak depolymerization of more common, high-crystallinity (30-50%) PETs. Here, based on the thermophilic PETase, LCCICCG, we proposed two strategies for rational redesign of LCCICCG using the machine learning tool, Preoptem, combined with evolutionary analysis. Six single-point mutants (S32L, D18T, S98R, T157P, E173Q, N213P) were obtained that exhibit higher catalytic efficiency towards PET powder than wild-type LCCICCG at 75 °C. Additionally, the optimal temperature for degrading 39.07% crystalline PET increased from 65 °C in the wild-type LCCICCG to between 75 and 80 °C in the LCCICCG_I6M mutant that carries all six single-point mutations. Especially, the LCCICCG_I6M mutant has a significantly higher degradation effect on some commonly used bottle-grade plastic powders at 75-80 °C than that of wild type. The enzymatic digestion of ground 31.30% crystalline PET water bottles by LCCICCG_I6M yielded 31.91 ± 0.99 mM soluble products in 24 h, which was 3.64 times that of LCCICCG (8.77 ± 1.52 mM). Overall, this study provides a feasible route for engineering thermostable enzymes that can degrade high-crystallinity PET plastic.
Collapse
Affiliation(s)
- Zundan Ding
- Biotechnology Research Institute, Chinese Academy of Agricultural Sciences, Beijing 100081, China
| | - Guoshun Xu
- Institute of Animal Science, Chinese Academy of Agricultural Sciences, Beijing 100193, China
| | - Ruiju Miao
- Biotechnology Research Institute, Chinese Academy of Agricultural Sciences, Beijing 100081, China; College of Bioscience and Engineering, Hebei University of Economics and Business, Hebei Province 050061, China
| | - Ningfeng Wu
- Biotechnology Research Institute, Chinese Academy of Agricultural Sciences, Beijing 100081, China
| | - Wei Zhang
- Biotechnology Research Institute, Chinese Academy of Agricultural Sciences, Beijing 100081, China
| | - Bin Yao
- Institute of Animal Science, Chinese Academy of Agricultural Sciences, Beijing 100193, China
| | - Feifei Guan
- Biotechnology Research Institute, Chinese Academy of Agricultural Sciences, Beijing 100081, China.
| | - Huoqing Huang
- Institute of Animal Science, Chinese Academy of Agricultural Sciences, Beijing 100193, China.
| | - Jian Tian
- Biotechnology Research Institute, Chinese Academy of Agricultural Sciences, Beijing 100081, China; Institute of Animal Science, Chinese Academy of Agricultural Sciences, Beijing 100193, China.
| |
Collapse
|
32
|
Di Rocco G, Taunt HN, Berto M, Jackson HO, Piccinini D, Carletti A, Scurani G, Braidi N, Purton S. A PETase enzyme synthesised in the chloroplast of the microalga Chlamydomonas reinhardtii is active against post-consumer plastics. Sci Rep 2023; 13:10028. [PMID: 37340047 DOI: 10.1038/s41598-023-37227-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2023] [Accepted: 06/18/2023] [Indexed: 06/22/2023] Open
Abstract
Polyethylene terephthalate hydrolases (PETases) are a newly discovered and industrially important class of enzymes that catalyze the enzymatic degradation of polyethylene terephatalate (PET), one of the most abundant plastics in the world. The greater enzymatic efficiencies of PETases compared to close relatives from the cutinase and lipase families have resulted in increasing research interest. Despite this, further characterization of PETases is essential, particularly regarding their possible activity against other kinds of plastic. In this study, we exploited for the first time the use of the microalgal chloroplast for more sustainable synthesis of a PETase enzyme. A photosynthetic-restoration strategy was used to generate a marker-free transformant line of the green microalga Chlamydomonas reinhardtii in which the PETase from Ideonella sakaiensis was constitutively expressed in the chloroplast. Subsequently, the activity of the PETase against both PET and post-consumer plastics was investigated via atomic force microscopy, revealing evidence of degradation of the plastics.
Collapse
Affiliation(s)
- Giulia Di Rocco
- Department of Life Sciences, University of Modena and Reggio Emilia, 41125, Modena, Italy.
| | - Henry N Taunt
- Algal Research Group, Department of Structural and Molecular Biology, University College London, Gower Street, London, UK
| | - Marcello Berto
- Department of Life Sciences, University of Modena and Reggio Emilia, 41125, Modena, Italy
| | - Harry O Jackson
- Algal Research Group, Department of Structural and Molecular Biology, University College London, Gower Street, London, UK
| | - Daniele Piccinini
- Department of Life Sciences, University of Modena and Reggio Emilia, 41125, Modena, Italy
| | - Alan Carletti
- Department of Life Sciences, University of Modena and Reggio Emilia, 41125, Modena, Italy
| | - Giulia Scurani
- Department of Chemical and Geological Sciences, University of Modena and Reggio Emilia, 41125, Modena, Italy
| | - Niccolò Braidi
- Department of Chemical and Geological Sciences, University of Modena and Reggio Emilia, 41125, Modena, Italy
| | - Saul Purton
- Algal Research Group, Department of Structural and Molecular Biology, University College London, Gower Street, London, UK
| |
Collapse
|
33
|
Zheng M, Li Y, Dong W, Zhang Q, Wang W. Enantioselectivity and origin of enhanced efficiency in polyethylene terephthalate hydrolases catalyzed depolymerization. JOURNAL OF HAZARDOUS MATERIALS 2023; 452:131295. [PMID: 36989777 DOI: 10.1016/j.jhazmat.2023.131295] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/10/2023] [Revised: 03/23/2023] [Accepted: 03/24/2023] [Indexed: 05/03/2023]
Abstract
Biotechnology is one of the most promising strategies to resolve the global crisis of plastic pollution. A clear understanding of the core enzyme mechanisms in the biotransformation process is critical for rational enzyme engineering and for practical, industrial-scale applications. Herein, we systematically examined and evidenced a largely unexplored piece in the depolymerization mechanism catalyzed by polyethylene terephthalate (PET) hydrolases: their enantioselectivity. We found that all the short-lived tetrahedron intermediates (IM3 and IM8) possess S-type chirality in six representative PET hydrolases. For instance, the binding percentage ratio of pro-S:pro-R is 57:21 in FAST-PETase, while pro-S binding leads to a much lower average energy barrier (5.2 kcal/mol) than pro-R binding (33.1 kcal/mol). Key structural features (e.g. the angle for Ser@H1-His@N1-PET@O2 and distance for His@N1-PET@O2) that significantly modulate the enantioselectivity were identified. The origin of the energy landscape variation between wild-type IsPETase and mutant FAST-PETase was also unveiled via analysis of key features, the distortion/interaction energy, and non-covalent bond interactions. This study supplies the missing piece in the mechanism for depolymerization catalyzed by PET hydrolases, and will aid in the rational design of enzymes for industrial recycling of PET plastic waste.
Collapse
Affiliation(s)
- Mingna Zheng
- Environment Research Institute, Shandong University, Qingdao 266237, PR China
| | - Yanwei Li
- Environment Research Institute, Shandong University, Qingdao 266237, PR China; Shenzhen Research Institute, Shandong University, Shenzhen 518057, PR China.
| | - Weiliang Dong
- State Key Laboratory of Materials-Oriented Chemical Engineering, College of Biotechnology and Pharmaceutical Engineering, Nanjing Tech University, Nanjing 211800, PR China
| | - Qingzhu Zhang
- Environment Research Institute, Shandong University, Qingdao 266237, PR China
| | - Wenxing Wang
- Environment Research Institute, Shandong University, Qingdao 266237, PR China
| |
Collapse
|
34
|
Fransen KA, Av-Ron SHM, Buchanan TR, Walsh DJ, Rota DT, Van Note L, Olsen BD. High-throughput experimentation for discovery of biodegradable polyesters. Proc Natl Acad Sci U S A 2023; 120:e2220021120. [PMID: 37252959 PMCID: PMC10266013 DOI: 10.1073/pnas.2220021120] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2022] [Accepted: 03/08/2023] [Indexed: 06/01/2023] Open
Abstract
The consistent rise of plastic pollution has stimulated interest in the development of biodegradable plastics. However, the study of polymer biodegradation has historically been limited to a small number of polymers due to costly and slow standard methods for measuring degradation, slowing new material innovation. High-throughput polymer synthesis and a high-throughput polymer biodegradation method are developed and applied to generate a biodegradation dataset for 642 chemically distinct polyesters and polycarbonates. The biodegradation assay was based on the clear-zone technique, using automation to optically observe the degradation of suspended polymer particles under the action of a single Pseudomonas lemoignei bacterial colony. Biodegradability was found to depend strongly on aliphatic repeat unit length, with chains less than 15 carbons and short side chains improving biodegradability. Aromatic backbone groups were generally detrimental to biodegradability; however, ortho- and para-substituted benzene rings in the backbone were more likely to be degradable than metasubstituted rings. Additionally, backbone ether groups improved biodegradability. While other heteroatoms did not show a clear improvement in biodegradability, they did demonstrate increases in biodegradation rates. Machine learning (ML) models were leveraged to predict biodegradability on this large dataset with accuracies over 82% using only chemical structure descriptors.
Collapse
Affiliation(s)
- Katharina A. Fransen
- Department of Chemical Engineering, Massachusetts Institute of Technology, Cambridge, MA02139
| | - Sarah H. M. Av-Ron
- Department of Chemical Engineering, Massachusetts Institute of Technology, Cambridge, MA02139
| | - Tess R. Buchanan
- Department of Chemical Engineering, Massachusetts Institute of Technology, Cambridge, MA02139
| | - Dylan J. Walsh
- Department of Chemical Engineering, Massachusetts Institute of Technology, Cambridge, MA02139
| | - Dechen T. Rota
- Department of Chemical Engineering, Massachusetts Institute of Technology, Cambridge, MA02139
| | - Lana Van Note
- Department of Chemical Engineering, Massachusetts Institute of Technology, Cambridge, MA02139
| | - Bradley D. Olsen
- Department of Chemical Engineering, Massachusetts Institute of Technology, Cambridge, MA02139
| |
Collapse
|
35
|
Jayasekara SK, Joni HD, Jayantha B, Dissanayake L, Mandrell C, Sinharage MM, Molitor R, Jayasekara T, Sivakumar P, Jayakody LN. Trends in in-silico guided engineering of efficient polyethylene terephthalate (PET) hydrolyzing enzymes to enable bio-recycling and upcycling of PET. Comput Struct Biotechnol J 2023; 21:3513-3521. [PMID: 37484494 PMCID: PMC10362282 DOI: 10.1016/j.csbj.2023.06.004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2023] [Revised: 06/01/2023] [Accepted: 06/03/2023] [Indexed: 07/25/2023] Open
Abstract
Polyethylene terephthalate (PET) is the largest produced polyester globally, and less than 30% of all the PET produced globally (∼6 billion pounds annually) is currently recycled into lower-quality products. The major drawbacks in current recycling methods (mechanical and chemical), have inspired the exploration of potentially efficient and sustainable PET depolymerization using biological approaches. Researchers have discovered efficient PET hydrolyzing enzymes in the plastisphere and have demonstrated the selective degradation of PET to original monomers thus enabling biological recycling or upcycling. However, several significant hurdles such as the less efficiency of the hydrolytic reaction, low thermostability of the enzymes, and the inability of the enzyme to depolymerize crystalline PET must be addressed in order to establish techno-economically feasible commercial-scale biological PET recycling or upcycling processes. Researchers leverage a synthetic biology-based design; build, test, and learn (DBTL) methodology to develop commercially applicable efficient PET hydrolyzing enzymes through 1) high-throughput metagenomic and proteomic approaches to discover new PET hydrolyzing enzymes with superior properties: and, 2) enzyme engineering approaches to modify and optimize PET hydrolyzing properties. Recently, in-silico platforms including molecular mechanics and machine learning concepts are emerging as innovative tools for the development of more efficient and effective PET recycling through the exploration of novel mutations in PET hydrolyzing enzymes. In-silico-guided PET hydrolyzing enzyme engineering with DBTL cycles enables the rapid development of efficient variants of enzymes over tedious conventional enzyme engineering methods such as random or directed evolution. This review highlights the potential of in-silico-guided PET degrading enzyme engineering to create more efficient variants, including Ideonella sakaiensis PETase (IsPETase) and leaf-branch compost cutinases (LCC). Furthermore, future research prospects are discussed to enable a sustainable circular economy through the bioconversion of PET to original or high-value platform chemicals.
Collapse
Affiliation(s)
- Sandhya K. Jayasekara
- School of Biological Science, Southern Illinois University Carbondale, Carbondale, IL, USA
| | - Hriday Dhar Joni
- School of Physics and Applied Physics, Southern Illinois University Carbondale, Carbondale, IL, USA
| | - Bhagya Jayantha
- School of Biological Science, Southern Illinois University Carbondale, Carbondale, IL, USA
| | - Lakshika Dissanayake
- School of Biological Science, Southern Illinois University Carbondale, Carbondale, IL, USA
| | - Christopher Mandrell
- School of Physics and Applied Physics, Southern Illinois University Carbondale, Carbondale, IL, USA
| | - Manuka M.S. Sinharage
- School of Physics and Applied Physics, Southern Illinois University Carbondale, Carbondale, IL, USA
| | - Ryan Molitor
- School of Physics and Applied Physics, Southern Illinois University Carbondale, Carbondale, IL, USA
| | - Thushari Jayasekara
- School of Physics and Applied Physics, Southern Illinois University Carbondale, Carbondale, IL, USA
| | - Poopalasingam Sivakumar
- School of Physics and Applied Physics, Southern Illinois University Carbondale, Carbondale, IL, USA
| | - Lahiru N. Jayakody
- School of Biological Science, Southern Illinois University Carbondale, Carbondale, IL, USA
- Fermentation Science Institute, Southern Illinois University Carbondale, Carbondale, IL, USA
| |
Collapse
|
36
|
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.
Collapse
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
| |
Collapse
|
37
|
Xu A, Zhou J, Blank LM, Jiang M. Future focuses of enzymatic plastic degradation. Trends Microbiol 2023:S0966-842X(23)00114-2. [PMID: 37121829 DOI: 10.1016/j.tim.2023.04.002] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2023] [Revised: 04/04/2023] [Accepted: 04/06/2023] [Indexed: 05/02/2023]
Abstract
Enzyme-based plastic degradation and valorization of the plastic-derived monomers has emerged as a potent option to address the plastic waste dilemma. Obstacles in implementing the enzymatic degradation of plastics in industry are here summarized, and strategies to overcome these obstacles are discussed to exploit the full potential of enzymatic plastic degradation toward a sustainable plastic economy.
Collapse
Affiliation(s)
- Anming Xu
- College of Biotechnology and Pharmaceutical Engineering, Nanjing Tech University, Nanjing, China
| | - Jie Zhou
- College of Biotechnology and Pharmaceutical Engineering, Nanjing Tech University, Nanjing, China; State Key Laboratory of Materials-Oriented Chemical Engineering, Nanjing Tech University, Nanjing, China; Key Laboratory for Waste Plastics Biocatalytic Degradation and Recycling, Nanjing Tech University, Nanjing, China.
| | - Lars M Blank
- Institute of Applied Microbiology (iAMB), Aachen Biology and Biotechnology (ABBt), RWTH Aachen University, Aachen, Germany.
| | - Min Jiang
- College of Biotechnology and Pharmaceutical Engineering, Nanjing Tech University, Nanjing, China; State Key Laboratory of Materials-Oriented Chemical Engineering, Nanjing Tech University, Nanjing, China; Key Laboratory for Waste Plastics Biocatalytic Degradation and Recycling, Nanjing Tech University, Nanjing, China.
| |
Collapse
|
38
|
Avilan L, Lichtenstein BR, König G, Zahn M, Allen MD, Oliveira L, Clark M, Bemmer V, Graham R, Austin HP, Dominick G, Johnson CW, Beckham GT, McGeehan JE, Pickford AR. Concentration-Dependent Inhibition of Mesophilic PETases on Poly(ethylene terephthalate) Can Be Eliminated by Enzyme Engineering. CHEMSUSCHEM 2023; 16:e202202277. [PMID: 36811288 DOI: 10.1002/cssc.202202277] [Citation(s) in RCA: 8] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/07/2022] [Revised: 02/17/2023] [Indexed: 06/18/2023]
Abstract
Enzyme-based depolymerization is a viable approach for recycling of poly(ethylene terephthalate) (PET). PETase from Ideonella sakaiensis (IsPETase) is capable of PET hydrolysis under mild conditions but suffers from concentration-dependent inhibition. In this study, this inhibition is found to be dependent on incubation time, the solution conditions, and PET surface area. Furthermore, this inhibition is evident in other mesophilic PET-degrading enzymes to varying degrees, independent of the level of PET depolymerization activity. The inhibition has no clear structural basis, but moderately thermostable IsPETase variants exhibit reduced inhibition, and the property is completely absent in the highly thermostable HotPETase, previously engineered by directed evolution, which simulations suggest results from reduced flexibility around the active site. This work highlights a limitation in applying natural mesophilic hydrolases for PET hydrolysis and reveals an unexpected positive outcome of engineering these enzymes for enhanced thermostability.
Collapse
Affiliation(s)
- Luisana Avilan
- Centre for Enzyme Innovation, School of Biological Sciences, Institute of Biological and Biomedical Sciences, University of Portsmouth, Portsmouth, PO1 2DY, United Kingdom
- BOTTLE Consortium, Golden, CO 80401, United States
| | - Bruce R Lichtenstein
- Centre for Enzyme Innovation, School of Biological Sciences, Institute of Biological and Biomedical Sciences, University of Portsmouth, Portsmouth, PO1 2DY, United Kingdom
- BOTTLE Consortium, Golden, CO 80401, United States
| | - Gerhard König
- Centre for Enzyme Innovation, School of Biological Sciences, Institute of Biological and Biomedical Sciences, University of Portsmouth, Portsmouth, PO1 2DY, United Kingdom
- BOTTLE Consortium, Golden, CO 80401, United States
| | - Michael Zahn
- Centre for Enzyme Innovation, School of Biological Sciences, Institute of Biological and Biomedical Sciences, University of Portsmouth, Portsmouth, PO1 2DY, United Kingdom
- BOTTLE Consortium, Golden, CO 80401, United States
| | - Mark D Allen
- Centre for Enzyme Innovation, School of Biological Sciences, Institute of Biological and Biomedical Sciences, University of Portsmouth, Portsmouth, PO1 2DY, United Kingdom
- BOTTLE Consortium, Golden, CO 80401, United States
| | - Liliana Oliveira
- Centre for Enzyme Innovation, School of Biological Sciences, Institute of Biological and Biomedical Sciences, University of Portsmouth, Portsmouth, PO1 2DY, United Kingdom
- BOTTLE Consortium, Golden, CO 80401, United States
| | - Matilda Clark
- Centre for Enzyme Innovation, School of Biological Sciences, Institute of Biological and Biomedical Sciences, University of Portsmouth, Portsmouth, PO1 2DY, United Kingdom
- BOTTLE Consortium, Golden, CO 80401, United States
| | - Victoria Bemmer
- Centre for Enzyme Innovation, School of Biological Sciences, Institute of Biological and Biomedical Sciences, University of Portsmouth, Portsmouth, PO1 2DY, United Kingdom
- BOTTLE Consortium, Golden, CO 80401, United States
| | - Rosie Graham
- Centre for Enzyme Innovation, School of Biological Sciences, Institute of Biological and Biomedical Sciences, University of Portsmouth, Portsmouth, PO1 2DY, United Kingdom
- BOTTLE Consortium, Golden, CO 80401, United States
| | - Harry P Austin
- Institute of Biochemistry, Department of Biotechnology & Enzyme Catalysis, University of Greifswald, D-17487, Greifswald, Germany
| | - Graham Dominick
- Renewable Resources and Enabling Sciences Center, National Renewable Energy Laboratory, Golden, CO, 80401, United States
| | - Christopher W Johnson
- Renewable Resources and Enabling Sciences Center, National Renewable Energy Laboratory, Golden, CO, 80401, United States
| | - Gregg T Beckham
- BOTTLE Consortium, Golden, CO 80401, United States
- Renewable Resources and Enabling Sciences Center, National Renewable Energy Laboratory, Golden, CO, 80401, United States
| | - John E McGeehan
- Centre for Enzyme Innovation, School of Biological Sciences, Institute of Biological and Biomedical Sciences, University of Portsmouth, Portsmouth, PO1 2DY, United Kingdom
- BOTTLE Consortium, Golden, CO 80401, United States
| | - Andrew R Pickford
- Centre for Enzyme Innovation, School of Biological Sciences, Institute of Biological and Biomedical Sciences, University of Portsmouth, Portsmouth, PO1 2DY, United Kingdom
- BOTTLE Consortium, Golden, CO 80401, United States
| |
Collapse
|
39
|
Huang D, Zhang L, Sun Y. Rational Design of Disulfide Bridges in BbPETase CD for Enhancing the Enzymatic Performance in PET Degradation. Molecules 2023; 28:molecules28083528. [PMID: 37110762 PMCID: PMC10146679 DOI: 10.3390/molecules28083528] [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: 03/21/2023] [Revised: 04/12/2023] [Accepted: 04/15/2023] [Indexed: 04/29/2023] Open
Abstract
Polyethylene terephthalate (PET) is one of the most prevalent transparent thermoplastics. It is commonly utilized due to its low cost and high durability. With the massive accumulation of waste PET, however, serious environmental pollution has become a global problem. Compared to traditional chemical degradation, biodegradation of PET catalyzed by PET hydrolase (PETase) is more environmentally friendly and energy-efficient. BbPETaseCD from the Burkholderiales bacterium is a PETase that shows favorable properties for application in the biodegradation of PET. To enhance the enzymatic performance of this enzyme, this work focuses on the rational design of disulfide bridges in BbPETaseCD. We utilized two computational algorithms to predict the probable disulfide-bridge mutations in BbPETaseCD, and five variants were acquired from the computations. Among these, the N364C/D418C variant with one additional disulfide bond showed higher expression than the wild-type enzyme (WT) and the best enzymatic performance. The melting temperature (Tm) of the N364C/D418C variant presented an increase of 14.8 °C over that of WT (56.5 °C), indicating that the additional disulfide bond significantly raised the thermodynamic stability of the enzyme. Kinetic experiments at different temperatures also demonstrated the thermal stability increase of the variant. The variant also showed significantly increased activity over WT when using bis(hydroxyethyl) terephthalate (BHET) as the substrate. More remarkably, the N364C/D418C variant exhibited approximately an 11-fold increase over the WT enzyme in the long-term (14 days) degradation of PET films. The results prove that the rationally designed disulfide bond significantly improved the enzymatic performance of the enzyme for PET degradation.
Collapse
Affiliation(s)
- Dongjian Huang
- Department of Biochemical Engineering, School of Chemical Engineering and Technology, Tianjin University, Tianjin 300350, China
| | - Lin Zhang
- Department of Biochemical Engineering, School of Chemical Engineering and Technology, Tianjin University, Tianjin 300350, China
- Key Laboratory of Systems Bioengineering and Frontiers Science Center for Synthetic Biology (Ministry of Education), Tianjin University, Tianjin 300350, China
| | - Yan Sun
- Department of Biochemical Engineering, School of Chemical Engineering and Technology, Tianjin University, Tianjin 300350, China
- Key Laboratory of Systems Bioengineering and Frontiers Science Center for Synthetic Biology (Ministry of Education), Tianjin University, Tianjin 300350, China
| |
Collapse
|
40
|
Crnjar A, Griñen A, Kamerlin SCL, Ramírez-Sarmiento CA. Conformational Selection of a Tryptophan Side Chain Drives the Generalized Increase in Activity of PET Hydrolases through a Ser/Ile Double Mutation. ACS ORGANIC & INORGANIC AU 2023; 3:109-119. [PMID: 37035283 PMCID: PMC10080609 DOI: 10.1021/acsorginorgau.2c00054] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 10/07/2022] [Revised: 12/15/2022] [Accepted: 12/15/2022] [Indexed: 04/12/2023]
Abstract
Poly(ethylene terephthalate) (PET) is the most common polyester plastic in the packaging industry and a major source of environmental pollution due to its single use. Several enzymes, termed PET hydrolases, have been found to hydrolyze this polymer at different temperatures, with the enzyme from Ideonella sakaiensis (IsPETase) having optimal catalytic activity at 30-35 °C. Crystal structures of IsPETase have revealed that the side chain of a conserved tryptophan residue within an active site loop (W185) shifts between three conformations to enable substrate binding and product release. This is facilitated by two residues unique to IsPETase, S214 and I218. When these residues are inserted into other PET hydrolases in place of the otherwise strictly conserved histidine and phenylalanine residues found at their respective positions, they enhance activity and decrease T opt. Herein, we combine molecular dynamics and well-tempered metadynamics simulations to investigate dynamic changes of the S214/I218 and H214/F218 variants of IsPETase, as well as three other mesophilic and thermophilic PET hydrolases, at their respective temperature and pH optima. Our simulations show that the S214/I218 insertion both increases the flexibility of active site loop regions harboring key catalytic residues and the conserved tryptophan and expands the conformational plasticity of this tryptophan side chain, enabling the conformational transitions that allow for substrate binding and product release in IsPETase. The observed catalytic enhancement caused by this substitution in other PET hydrolases appears to be due to conformational selection, by capturing the conformational ensemble observed in IsPETase.
Collapse
Affiliation(s)
- Alessandro Crnjar
- Department
of Chemistry—BMC, Uppsala University, BMC Box 576, S-751 23 Uppsala, Sweden
| | - Aransa Griñen
- Institute
for Biological and Medical Engineering, Schools of Engineering, Medicine
and Biological Sciences, Pontificia Universidad
Católica de Chile, Av. Vicuña Mackenna 4860, Santiago 7820436, Chile
- ANID—Millennium
Science Initiative Program—Millennium Institute for Integrative
Biology (iBio), Av. Libertador
Bernardo O’Higgins 340, Santiago 8331150, Chile
| | - Shina C. L. Kamerlin
- Department
of Chemistry—BMC, Uppsala University, BMC Box 576, S-751 23 Uppsala, Sweden
- School
of Chemistry and Biochemistry, Georgia Institute
of Technology, 901 Atlantic
Drive NW, Atlanta, Georgia 30332-0400, United
States
| | - César A. Ramírez-Sarmiento
- Institute
for Biological and Medical Engineering, Schools of Engineering, Medicine
and Biological Sciences, Pontificia Universidad
Católica de Chile, Av. Vicuña Mackenna 4860, Santiago 7820436, Chile
- ANID—Millennium
Science Initiative Program—Millennium Institute for Integrative
Biology (iBio), Av. Libertador
Bernardo O’Higgins 340, Santiago 8331150, Chile
| |
Collapse
|
41
|
Shi L, Liu P, Tan Z, Zhao W, Gao J, Gu Q, Ma H, Liu H, Zhu L. Complete Depolymerization of PET Wastes by an Evolved PET Hydrolase from Directed Evolution. Angew Chem Int Ed Engl 2023; 62:e202218390. [PMID: 36751696 DOI: 10.1002/anie.202218390] [Citation(s) in RCA: 19] [Impact Index Per Article: 19.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2022] [Revised: 02/02/2023] [Accepted: 02/07/2023] [Indexed: 02/09/2023]
Abstract
PETase displays great potential in PET depolymerization. Directed evolution has been limited to engineer PETase due to the lack of high-throughput screening assay. In this study, a novel fluorescence-based high-throughput screening assay employing a newly designed substrate, bis (2-hydroxyethyl) 2-hydroxyterephthalate (termed BHET-OH), was developed for PET hydrolases. The best variant DepoPETase produced 1407-fold more products towards amorphous PET film at 50 °C and showed a 23.3 °C higher Tm value than the PETase WT. DepoPETase enabled complete depolymerization of seven untreated PET wastes and 19.1 g PET waste (0.4 % Wenzyme /WPET ) in liter-scale reactor, suggesting that it is a potential candidate for industrial PET depolymerization processes. The molecular dynamic simulations revealed that the distal substitutions stabilized the loops around the active sites and transmitted the stabilization effect to the active sites through enhancing inter-loop interactions network.
Collapse
Affiliation(s)
- Lixia Shi
- University of Chinese Academy of Sciences, 19A Yuquan Road, Beijing, 100049, China
- Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, 32 West 7th Avenue, Tianjin Airport Economic Area, Tianjin, 300308, P. R. China
- National Technology Innovation Center of Synthetic Biology, 32 West 7th Avenue, Tianjin Airport Economic Area, Tianjin, 300308, P. R. China
| | - Pi Liu
- Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, 32 West 7th Avenue, Tianjin Airport Economic Area, Tianjin, 300308, P. R. China
- National Technology Innovation Center of Synthetic Biology, 32 West 7th Avenue, Tianjin Airport Economic Area, Tianjin, 300308, P. R. China
| | - Zijian Tan
- Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, 32 West 7th Avenue, Tianjin Airport Economic Area, Tianjin, 300308, P. R. China
- Jiangsu Collaborative Innovation Centre of Chinese Medicinal Resources Industrialization, School of Pharmacy, Nanjing University of Chinese Medicine, Nanjing, 210023, China
| | - Wei Zhao
- Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, 32 West 7th Avenue, Tianjin Airport Economic Area, Tianjin, 300308, P. R. China
- National Technology Innovation Center of Synthetic Biology, 32 West 7th Avenue, Tianjin Airport Economic Area, Tianjin, 300308, P. R. China
| | - Junfei Gao
- Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, 32 West 7th Avenue, Tianjin Airport Economic Area, Tianjin, 300308, P. R. China
- National Technology Innovation Center of Synthetic Biology, 32 West 7th Avenue, Tianjin Airport Economic Area, Tianjin, 300308, P. R. China
| | - Qun Gu
- Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, 32 West 7th Avenue, Tianjin Airport Economic Area, Tianjin, 300308, P. R. China
- National Technology Innovation Center of Synthetic Biology, 32 West 7th Avenue, Tianjin Airport Economic Area, Tianjin, 300308, P. R. China
| | - Hongwu Ma
- Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, 32 West 7th Avenue, Tianjin Airport Economic Area, Tianjin, 300308, P. R. China
- National Technology Innovation Center of Synthetic Biology, 32 West 7th Avenue, Tianjin Airport Economic Area, Tianjin, 300308, P. R. China
| | - Haifeng Liu
- Jiangsu Collaborative Innovation Centre of Chinese Medicinal Resources Industrialization, School of Pharmacy, Nanjing University of Chinese Medicine, Nanjing, 210023, China
| | - Leilei Zhu
- Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, 32 West 7th Avenue, Tianjin Airport Economic Area, Tianjin, 300308, P. R. China
- National Technology Innovation Center of Synthetic Biology, 32 West 7th Avenue, Tianjin Airport Economic Area, Tianjin, 300308, P. R. China
| |
Collapse
|
42
|
Tournier V, Duquesne S, Guillamot F, Cramail H, Taton D, Marty A, André I. Enzymes' Power for Plastics Degradation. Chem Rev 2023; 123:5612-5701. [PMID: 36916764 DOI: 10.1021/acs.chemrev.2c00644] [Citation(s) in RCA: 56] [Impact Index Per Article: 56.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/16/2023]
Abstract
Plastics are everywhere in our modern way of living, and their production keeps increasing every year, causing major environmental concerns. Nowadays, the end-of-life management involves accumulation in landfills, incineration, and recycling to a lower extent. This ecological threat to the environment is inspiring alternative bio-based solutions for plastic waste treatment and recycling toward a circular economy. Over the past decade, considerable efforts have been made to degrade commodity plastics using biocatalytic approaches. Here, we provide a comprehensive review on the recent advances in enzyme-based biocatalysis and in the design of related biocatalytic processes to recycle or upcycle commodity plastics, including polyesters, polyamides, polyurethanes, and polyolefins. We also discuss scope and limitations, challenges, and opportunities of this field of research. An important message from this review is that polymer-assimilating enzymes are very likely part of the solution to reaching a circular plastic economy.
Collapse
Affiliation(s)
- Vincent Tournier
- Carbios, Parc Cataroux-Bâtiment B80, 8 rue de la Grolière, 63100 Clermont-Ferrand, France
| | - Sophie Duquesne
- Toulouse Biotechnology Institute, TBI, Université de Toulouse, CNRS, INRAE, INSA, Toulouse, France, 135, avenue de Rangueil, F-31077 Toulouse Cedex 04, France
| | - Frédérique Guillamot
- Carbios, Parc Cataroux-Bâtiment B80, 8 rue de la Grolière, 63100 Clermont-Ferrand, France
| | - Henri Cramail
- Université Bordeaux, CNRS, Bordeaux INP, LCPO, 16 Avenue Pey-Berland, 33600 Pessac, France
| | - Daniel Taton
- Université Bordeaux, CNRS, Bordeaux INP, LCPO, 16 Avenue Pey-Berland, 33600 Pessac, France
| | - Alain Marty
- Carbios, Parc Cataroux-Bâtiment B80, 8 rue de la Grolière, 63100 Clermont-Ferrand, France
| | - Isabelle André
- Toulouse Biotechnology Institute, TBI, Université de Toulouse, CNRS, INRAE, INSA, Toulouse, France, 135, avenue de Rangueil, F-31077 Toulouse Cedex 04, France
| |
Collapse
|
43
|
Cannon JA, Reynolds TB. Synergistic Mutations Create Bacillus Subtilisin Variants with Enhanced Poly-l-Lactic Acid Depolymerization Activity. Biomacromolecules 2023; 24:1141-1154. [PMID: 36780360 DOI: 10.1021/acs.biomac.2c01198] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/14/2023]
Abstract
Enzymatic recycling of poly-l-lactic acid (PLLA) plastic has recently become an area of interest; however, investigation of enzymatic mechanisms and engineering strategies to improve activity remains limited. In this study, we have identified a subtilisin from Bacillus pumilus that has the ability to depolymerize high-molecular-weight PLLA. We performed a comparative, mutational analysis of this enzyme with a less active homologue from Bacillus subtilis to determine residues favored for activity. Our results demonstrate that both enzymes contain residues favored for PLLA depolymerization, with the generation of several hyperactive variants. In silico modeling suggests that increases in activity are due to opening of the binding pockets and increased surface hydrophobicity. Combinations of hyperactive mutations have synergistic effects with the generation of subtilisin variants with 830- and 184-fold increases in activity for B. subtilis and B. pumilus subtilisins, respectively. One B. pumilus subtilisin variant can visibly dissolve high-molecular-weight PLLA films.
Collapse
Affiliation(s)
- Jordan A Cannon
- Department of Microbiology, University of Tennessee at Knoxville, Knoxville, Tennessee 37996, United States
| | - Todd B Reynolds
- Department of Microbiology, University of Tennessee at Knoxville, Knoxville, Tennessee 37996, United States
| |
Collapse
|
44
|
Mrigwani A, Pitaliya M, Kaur H, Kasilingam B, Thakur B, Guptasarma P. Rational mutagenesis of Thermobifida fusca cutinase to modulate the enzymatic degradation of polyethylene terephthalate. Biotechnol Bioeng 2023; 120:674-686. [PMID: 36514261 DOI: 10.1002/bit.28305] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2022] [Revised: 12/08/2022] [Accepted: 12/11/2022] [Indexed: 12/15/2022]
Abstract
Thermobifida fusca cutinase (TfCut2) is a carboxylesterase (CE) which degrades polyethylene terephthalate (PET) as well as its degradation intermediates [such as oligoethylene terephthalate (OET), or bis-/mono-hydroxyethyl terephthalate (BHET/MHET)] into terephthalic acid (TPA). Comparisons of the surfaces of certain CEs (including TfCut2) were combined with docking and molecular dynamics simulations involving 2HE-(MHET)3, a three-terephthalate OET, to support the rational design of 22 variants with potential for improved generation of TPA from PET, comprising 15 single mutants (D12L, E47F, G62A, L90A, L90F, H129W, W155F, ΔV164, A173C, H184A, H184S, F209S, F209I, F249A, and F249R), 6 double mutants [H129W/T136S, A173C/A206C, A173C/A210C, G62A/L90F, G62A/F209I, and G62A/F249R], and 1 triple mutant [G62A/F209I/F249R]. Of these, nine displayed no activity, three displayed decreased activity, three displayed comparable activity, and seven displayed increased (~1.3- to ~7.2-fold) activity against solid PET, while all variants displayed activity against BHET. Of the variants that displayed increased activity against PET, four displayed more activity than G62A, the most-active mutant of TfCut2 known till date. Of these four, three displayed even more activity than LCC (G62A/F209I, G62A/F249R, and G62A/F209I/F249R), a CE known to be ~5-fold more active than wild-type TfCut2. These improvements derived from changes in PET binding and not changes in catalytic efficiency.
Collapse
Affiliation(s)
- Arpita Mrigwani
- Centre for Protein Science, Design and Engineering (CPSDE) and Hyperthermophile Enzyme Hydrolase Research Centre (HEHRC), Department of Biological Sciences, Indian Institute of Science Education and Research (IISER) Mohali, SAS Nagar (Mohali), Punjab, India
| | - Madhav Pitaliya
- Centre for Protein Science, Design and Engineering (CPSDE) and Hyperthermophile Enzyme Hydrolase Research Centre (HEHRC), Department of Biological Sciences, Indian Institute of Science Education and Research (IISER) Mohali, SAS Nagar (Mohali), Punjab, India
| | - Harman Kaur
- Centre for Protein Science, Design and Engineering (CPSDE) and Hyperthermophile Enzyme Hydrolase Research Centre (HEHRC), Department of Biological Sciences, Indian Institute of Science Education and Research (IISER) Mohali, SAS Nagar (Mohali), Punjab, India
| | - Bharathraj Kasilingam
- Centre for Protein Science, Design and Engineering (CPSDE) and Hyperthermophile Enzyme Hydrolase Research Centre (HEHRC), Department of Biological Sciences, Indian Institute of Science Education and Research (IISER) Mohali, SAS Nagar (Mohali), Punjab, India
| | - Bhishem Thakur
- Centre for Protein Science, Design and Engineering (CPSDE) and Hyperthermophile Enzyme Hydrolase Research Centre (HEHRC), Department of Biological Sciences, Indian Institute of Science Education and Research (IISER) Mohali, SAS Nagar (Mohali), Punjab, India
| | - Purnananda Guptasarma
- Centre for Protein Science, Design and Engineering (CPSDE) and Hyperthermophile Enzyme Hydrolase Research Centre (HEHRC), Department of Biological Sciences, Indian Institute of Science Education and Research (IISER) Mohali, SAS Nagar (Mohali), Punjab, India
| |
Collapse
|
45
|
Thermophilic Carboxylesterases from Hydrothermal Vents of the Volcanic Island of Ischia Active on Synthetic and Biobased Polymers and Mycotoxins. Appl Environ Microbiol 2023; 89:e0170422. [PMID: 36719236 PMCID: PMC9972953 DOI: 10.1128/aem.01704-22] [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] [Indexed: 02/01/2023] Open
Abstract
Hydrothermal vents are geographically widespread and host microorganisms with robust enzymes useful in various industrial applications. We examined microbial communities and carboxylesterases of two terrestrial hydrothermal vents of the volcanic island of Ischia (Italy) predominantly composed of Firmicutes, Proteobacteria, and Bacteroidota. High-temperature enrichment cultures with the polyester plastics polyhydroxybutyrate and polylactic acid (PLA) resulted in an increase of Thermus and Geobacillus species and to some extent Fontimonas and Schleiferia species. The screening at 37 to 70°C of metagenomic fosmid libraries from above enrichment cultures identified three hydrolases (IS10, IS11, and IS12), all derived from yet-uncultured Chloroflexota and showing low sequence identity (33 to 56%) to characterized enzymes. Enzymes expressed in Escherichia coli exhibited maximal esterase activity at 70 to 90°C, with IS11 showing the highest thermostability (90% activity after 20-min incubation at 80°C). IS10 and IS12 were highly substrate promiscuous and hydrolyzed all 51 monoester substrates tested. Enzymes were active with PLA, polyethylene terephthalate model substrate, and mycotoxin T-2 (IS12). IS10 and IS12 had a classical α/β-hydrolase core domain with a serine hydrolase catalytic triad (Ser155, His280, and Asp250) in their hydrophobic active sites. The crystal structure of IS11 resolved at 2.92 Å revealed the presence of a N-terminal β-lactamase-like domain and C-terminal lipocalin domain. The catalytic cleft of IS11 included catalytic Ser68, Lys71, Tyr160, and Asn162, whereas the lipocalin domain enclosed the catalytic cleft like a lid and contributed to substrate binding. Our study identified novel thermotolerant carboxylesterases with a broad substrate range, including polyesters and mycotoxins, for potential applications in biotechnology. IMPORTANCE High-temperature-active microbial enzymes are important biocatalysts for many industrial applications, including recycling of synthetic and biobased polyesters increasingly used in textiles, fibers, coatings and adhesives. Here, we identified three novel thermotolerant carboxylesterases (IS10, IS11, and IS12) from high-temperature enrichment cultures from Ischia hydrothermal vents and incubated with biobased polymers. The identified metagenomic enzymes originated from uncultured Chloroflexota and showed low sequence similarity to known carboxylesterases. Active sites of IS10 and IS12 had the largest effective volumes among the characterized prokaryotic carboxylesterases and exhibited high substrate promiscuity, including hydrolysis of polyesters and mycotoxin T-2 (IS12). Though less promiscuous than IS10 and IS12, IS11 had a higher thermostability with a high temperature optimum (80 to 90°C) for activity and hydrolyzed polyesters, and its crystal structure revealed an unusual lipocalin domain likely involved in substrate binding. The polyesterase activity of these enzymes makes them attractive candidates for further optimization and potential application in plastics recycling.
Collapse
|
46
|
Branson Y, Söltl S, Buchmann C, Wei R, Schaffert L, Badenhorst CPS, Reisky L, Jäger G, Bornscheuer UT. Urethanases for the Enzymatic Hydrolysis of Low Molecular Weight Carbamates and the Recycling of Polyurethanes. Angew Chem Int Ed Engl 2023; 62:e202216220. [PMID: 36591907 DOI: 10.1002/anie.202216220] [Citation(s) in RCA: 21] [Impact Index Per Article: 21.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2022] [Revised: 12/07/2022] [Accepted: 01/02/2023] [Indexed: 01/03/2023]
Abstract
Enzymatic degradation and recycling can reduce the environmental impact of plastics. Despite decades of research, no enzymes for the efficient hydrolysis of polyurethanes have been reported. Whereas the hydrolysis of the ester bonds in polyester-polyurethanes by cutinases is known, the urethane bonds in polyether-polyurethanes have remained inaccessible to biocatalytic hydrolysis. Here we report the discovery of urethanases from a metagenome library constructed from soil that had been exposed to polyurethane waste for many years. We then demonstrate the use of a urethanase in a chemoenzymatic process for polyurethane foam recycling. The urethanase hydrolyses low molecular weight dicarbamates resulting from chemical glycolysis of polyether-polyurethane foam, making this strategy broadly applicable to diverse polyether-polyurethane wastes.
Collapse
Affiliation(s)
- Yannick Branson
- Institute of Biochemistry, Dept. of Biotechnology and Enzyme Catalysis, Greifswald University, Felix Hausdorff Str. 4, 17487, Greifswald, Germany
| | - Simone Söltl
- Covestro Deutschland AG, Kaiser-Wilhelm-Allee 60, 51373, Leverkusen, Germany
| | - Carolin Buchmann
- Institute of Biochemistry, Dept. of Biotechnology and Enzyme Catalysis, Greifswald University, Felix Hausdorff Str. 4, 17487, Greifswald, Germany
| | - Ren Wei
- Institute of Biochemistry, Dept. of Biotechnology and Enzyme Catalysis, Greifswald University, Felix Hausdorff Str. 4, 17487, Greifswald, Germany
| | - Lena Schaffert
- Covestro Deutschland AG, Kaiser-Wilhelm-Allee 60, 51373, Leverkusen, Germany
| | - Christoffel P S Badenhorst
- Institute of Biochemistry, Dept. of Biotechnology and Enzyme Catalysis, Greifswald University, Felix Hausdorff Str. 4, 17487, Greifswald, Germany
| | - Lukas Reisky
- Covestro Deutschland AG, Kaiser-Wilhelm-Allee 60, 51373, Leverkusen, Germany
| | - Gernot Jäger
- Covestro Deutschland AG, Kaiser-Wilhelm-Allee 60, 51373, Leverkusen, Germany
| | - Uwe T Bornscheuer
- Institute of Biochemistry, Dept. of Biotechnology and Enzyme Catalysis, Greifswald University, Felix Hausdorff Str. 4, 17487, Greifswald, Germany
| |
Collapse
|
47
|
Microbial Enzyme Biotechnology to Reach Plastic Waste Circularity: Current Status, Problems and Perspectives. Int J Mol Sci 2023; 24:ijms24043877. [PMID: 36835289 PMCID: PMC9967032 DOI: 10.3390/ijms24043877] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2023] [Revised: 02/08/2023] [Accepted: 02/10/2023] [Indexed: 02/17/2023] Open
Abstract
The accumulation of synthetic plastic waste in the environment has become a global concern. Microbial enzymes (purified or as whole-cell biocatalysts) represent emerging biotechnological tools for waste circularity; they can depolymerize materials into reusable building blocks, but their contribution must be considered within the context of present waste management practices. This review reports on the prospective of biotechnological tools for plastic bio-recycling within the framework of plastic waste management in Europe. Available biotechnology tools can support polyethylene terephthalate (PET) recycling. However, PET represents only ≈7% of unrecycled plastic waste. Polyurethanes, the principal unrecycled waste fraction, together with other thermosets and more recalcitrant thermoplastics (e.g., polyolefins) are the next plausible target for enzyme-based depolymerization, even if this process is currently effective only on ideal polyester-based polymers. To extend the contribution of biotechnology to plastic circularity, optimization of collection and sorting systems should be considered to feed chemoenzymatic technologies for the treatment of more recalcitrant and mixed polymers. In addition, new bio-based technologies with a lower environmental impact in comparison with the present approaches should be developed to depolymerize (available or new) plastic materials, that should be designed for the required durability and for being susceptible to the action of enzymes.
Collapse
|
48
|
Characterization of a PBAT Degradation Carboxylesterase from Thermobacillus composti KWC4. Catalysts 2023. [DOI: 10.3390/catal13020340] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
The large amount of waste synthetic polyester plastics has complicated waste management and also endangering the environment due to improper littering. In this study, a novel carboxylesterase from Thermobacillus composti KWC4 (Tcca) was identified, heterologously expressed in Escherichia coli, purified and characterized with various plastic substrates. Irregular grooves were detected on polybutylene adipate terephthalate (PBAT) film by scanning electron microscopy (SEM) after Tcca treatment, and Tcca can also hydrolyze short–chain diester bis(hydroxyethyl) terephthalate (BHET). The optimal pH and temperature for Tcca were 7.0 and 40 °C, respectively. In order to explore its catalytic mechanism and improve its potential for plastic hydrolysis, we modeled the protein structure of Tcca and compared it with its homologous structures, and we identified positions that might be crucial for the binding of substrates. We generated a variety of Tcca variants by mutating these key positions; the variant F325A exhibited a more than 1.4–fold improvement in PBAT hydrolytic activity, and E80A exhibited a more than 4.1–fold increase in BHET activity when compared to the wild type. Tcca and its variants demonstrated future applicability for the recycling of bioplastic waste containing a PBAT fraction.
Collapse
|
49
|
Construction of Fusion Protein with Carbohydrate-Binding Module and Leaf-Branch Compost Cutinase to Enhance the Degradation Efficiency of Polyethylene Terephthalate. Int J Mol Sci 2023; 24:ijms24032780. [PMID: 36769118 PMCID: PMC9917269 DOI: 10.3390/ijms24032780] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2022] [Revised: 01/23/2023] [Accepted: 01/30/2023] [Indexed: 02/05/2023] Open
Abstract
Poly(ethylene terephthalate) (PET) is a manufactured plastic broadly available, whereas improper disposal of PET waste has become a serious burden on the environment. Leaf-branch compost cutinase (LCC) is one of the most powerful and promising PET hydrolases, and its mutant LCCICCG shows high catalytic activity and excellent thermal stability. However, low binding affinity with PET has been found to dramatically limit its further industrial application. Herein, TrCBM and CfCBM were rationally selected from the CAZy database to construct fusion proteins with LCCICCG, and mechanistic studies revealed that these two domains could bind with PET favorably via polar amino acids. The optimal temperatures of LCCICCG-TrCBM and CfCBM-LCCICCG were measured to be 70 and 80 °C, respectively. Moreover, these two fusion proteins exhibited favorable thermal stability, maintaining 53.1% and 48.8% of initial activity after the incubation at 90 °C for 300 min. Compared with LCCICCG, the binding affinity of LCCICCG-TrCBM and CfCBM-LCCICCG for PET has been improved by 1.4- and 1.3-fold, respectively, and meanwhile their degradation efficiency on PET films was enhanced by 3.7% and 24.2%. Overall, this study demonstrated that the strategy of constructing fusion proteins is practical and prospective to facilitate the enzymatic PET degradation ability.
Collapse
|
50
|
Hayes HC, Luk LYP. Investigating the effects of cyclic topology on the performance of a plastic degrading enzyme for polyethylene terephthalate degradation. Sci Rep 2023; 13:1267. [PMID: 36690710 PMCID: PMC9870871 DOI: 10.1038/s41598-023-27780-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2022] [Accepted: 01/09/2023] [Indexed: 01/24/2023] Open
Abstract
Agitation is a commonly encountered stress for enzymes during all stages of production and application, but investigations that aim to improve their tolerance using topological engineering have yet to be reported. Here, the plastic-degrading enzyme IsPETase was cyclized in a range of topologies including a cyclic monomer, cyclic dimer and catenane using SpyTag/SpyCatcher technologies, and their tolerance towards different stresses including mechanical agitation was investigated. The cyclic dimer and catenane topologies were less susceptible to agitation-induced inactivation resulting in enhancement of polyethylene terephthalate (PET) degradation. While contrary to conventional belief, cyclic topologies did not improve tolerance of IsPETase towards heat or proteolytic treatment, the close proximity of active sites in the dimeric and catenane variants was found to enhance PET conversion into small soluble products. Together, these findings illustrate that it is worthwhile to explore the topology engineering of enzymes used in heterogeneous catalysis as it improves factors that are often overlooked in homogeneous catalysis studies.
Collapse
Affiliation(s)
- Heather C Hayes
- School of Chemistry, Cardiff University Main Building, Park Place, Cardiff, CF10 3AT, UK
- Cardiff Catalysis Institute, Cardiff University Main Building, Park Place, Cardiff, CF10 3AT, UK
| | - Louis Y P Luk
- School of Chemistry, Cardiff University Main Building, Park Place, Cardiff, CF10 3AT, UK.
- Cardiff Catalysis Institute, Cardiff University Main Building, Park Place, Cardiff, CF10 3AT, UK.
| |
Collapse
|