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Bertolini FA, Soccio M, Weinberger S, Guidotti G, Gazzano M, Guebitz GM, Lotti N, Pellis A. Unveiling the Enzymatic Degradation Process of Biobased Thiophene Polyesters. Front Chem 2021; 9:771612. [PMID: 34869219 PMCID: PMC8634338 DOI: 10.3389/fchem.2021.771612] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2021] [Accepted: 09/29/2021] [Indexed: 11/18/2022] Open
Abstract
In the past 20 years, scientific research focused on the identification of valid alternatives to materials of fossil origin, in particular, related to biobased polymers. Recently, the efforts led to the synthesis of thiophene-based polymers (TBPs), a new class of polyesters based on 2,5-thiophenedicarboxylic acid (TPCA) that can be industrially produced using biomass-derived molecules. In this study, TBPs were synthesized using diols with different chain length (from C4 to C6) leading to poly(butylene 2,5-thiophenedicarboxylate) (PBTF), poly(pentamethylene 2,5-thiophenedicarboxylate) (PPeTF), and poly(hexamethylene 2,5-thiophenedicarboxylate) (PHTF), respectively, that were processed to thin films. To investigate enzymatic hydrolysis of these polymer films, cutinase 1 (Thc_cut1) and cutinase 2 (Thc_cut2) from Thermobifida cellulosilytica were recombinantly expressed in the host E. coli and purified. After 72 h of incubation at 65°C with 5 µM Thc_cut1, weight loss and HPLC analysis indicated 9, 100, and 80% degradation of PBTF, PPeTF, and PHTG with a concomitant release of 0.12, 2.70, and 0.67 mM of TPCA. The SEM analysis showed that tiny holes were formed on the surface of the films and after 72 h PPeTF was completely degraded. The LC-TOF/MS analysis indicated that Thc_cut2 in particular released various oligomers from the polymer during the reaction. In addition, the FTIR analysis showed the formation of novel acid and hydroxyl groups on the polymer surfaces. The results showed that the two used thermostable cutinases are promising biocatalysts for the environmentally friendly degradation of TPCA-based polyesters, in view of a possible sustainable recycling of plastic waste through resynthesis processes.
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Affiliation(s)
- Federico A Bertolini
- Department of Agrobiotechnology, Institute of Environmental Biotechnology, University of Natural Resources and Life Sciences, Vienna, Tulln an der Donau, Austria
| | - Michelina Soccio
- Department of Civil, Chemical, Environmental and Materials Engineering, University of Bologna, Bologna, Italy
| | - Simone Weinberger
- Department of Agrobiotechnology, Institute of Environmental Biotechnology, University of Natural Resources and Life Sciences, Vienna, Tulln an der Donau, Austria
| | - Giulia Guidotti
- Department of Civil, Chemical, Environmental and Materials Engineering, University of Bologna, Bologna, Italy
| | - Massimo Gazzano
- Organic Synthesis and Photoreactivity Institute, CNR, Bologna, Italy
| | - Georg M Guebitz
- Department of Agrobiotechnology, Institute of Environmental Biotechnology, University of Natural Resources and Life Sciences, Vienna, Tulln an der Donau, Austria.,Austrian Centre of Industrial Biotechnology, Tulln an der Donau, Austria
| | - Nadia Lotti
- Department of Civil, Chemical, Environmental and Materials Engineering, University of Bologna, Bologna, Italy
| | - Alessandro Pellis
- Department of Agrobiotechnology, Institute of Environmental Biotechnology, University of Natural Resources and Life Sciences, Vienna, Tulln an der Donau, Austria.,Austrian Centre of Industrial Biotechnology, Tulln an der Donau, Austria.,Core Facility Bioactive Molecules Screening and Analysis, University of Natural Resources and Life Sciences, Vienna, Tulln an der Donau, Austria
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Novy V, Carneiro LV, Shin JH, Larsbrink J, Olsson L. Phylogenetic analysis and in-depth characterization of functionally and structurally diverse CE5 cutinases. J Biol Chem 2021; 297:101302. [PMID: 34653507 PMCID: PMC8577158 DOI: 10.1016/j.jbc.2021.101302] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2021] [Revised: 09/19/2021] [Accepted: 09/26/2021] [Indexed: 11/30/2022] Open
Abstract
Cutinases are esterases that release fatty acids from the apoplastic layer in plants. As they accept bulky and hydrophobic substrates, cutinases could be used in many applications, ranging from valorization of bark-rich side streams to plastic recycling. Advancement of these applications, however, requires deeper knowledge of cutinases' biodiversity and structure-function relationships. Here, we mined over 3000 members from carbohydrate esterase family 5 for putative cutinases and condensed it to 151 genes from known or putative lignocellulose-targeting organisms. The 151 genes were subjected to a phylogenetic analysis, which showed that cutinases with available crystal structures were phylogenetically closely related. We then selected nine phylogenic diverse cutinases for recombinant production and characterized their kinetic activity against para-nitrophenol substrates esterified with consecutively longer alkyl chains (pNP-C2 to C16). Each investigated cutinase had a unique activity fingerprint against the tested pNP substrates. The five enzymes with the highest activity on pNP-C12 and C16, indicative of activity on bulky hydrophobic compounds, were selected for in-depth kinetic and structure-function analysis. All five enzymes showed a decrease in kcat values with increasing substrate chain length, whereas KM values and binding energies (calculated from in silico docking analysis) improved. Two cutinases from Fusarium solani and Cryptococcus sp. exhibited outstandingly low KM values, resulting in high catalytic efficiencies toward pNP-C16. Docking analysis suggested that different clades of the phylogenetic tree may harbor enzymes with different modes of substrate interaction, involving a solvent-exposed catalytic triad, a lipase-like lid, or a clamshell-like active site possibly formed by flexible loops.
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Affiliation(s)
- Vera Novy
- Division of Industrial Biotechnology, Department of Biology and Biological Engineering, Chalmers University of Technology, Gothenburg, Sweden; Wallenberg Wood Science Center, Chalmers University of Technology, Gothenburg, Sweden
| | - Leonor Vieira Carneiro
- Division of Industrial Biotechnology, Department of Biology and Biological Engineering, Chalmers University of Technology, Gothenburg, Sweden
| | - Jae Ho Shin
- Division of Industrial Biotechnology, Department of Biology and Biological Engineering, Chalmers University of Technology, Gothenburg, Sweden
| | - Johan Larsbrink
- Division of Industrial Biotechnology, Department of Biology and Biological Engineering, Chalmers University of Technology, Gothenburg, Sweden; Wallenberg Wood Science Center, Chalmers University of Technology, Gothenburg, Sweden
| | - Lisbeth Olsson
- Division of Industrial Biotechnology, Department of Biology and Biological Engineering, Chalmers University of Technology, Gothenburg, Sweden; Wallenberg Wood Science Center, Chalmers University of Technology, Gothenburg, Sweden.
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Kawai F. Emerging Strategies in Polyethylene Terephthalate Hydrolase Research for Biorecycling. ChemSusChem 2021; 14:4115-4122. [PMID: 33949146 DOI: 10.1002/cssc.202100740] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/10/2021] [Revised: 05/02/2021] [Indexed: 06/12/2023]
Abstract
The research on polyethylene terephthalate (PET) hydrolyzing enzymes started in 2005; several studies are now nearing the objective of their application in biorecycling of PET, which is an urgent environmental issue. The thermostability of PET hydrolases must be higher than 70 °C, which has already been established by several thermophilic cutinases, as higher thermostability results in higher activity. Additionally, pretreatment of waste PET to more enzyme-attackable forms is necessary for PET biorecycling. This Minireview summarizes research on enzymatic PET hydrolysis from two viewpoints: 1) improvement of PET hydrolases by focusing on their thermostabilities by mutation of enzyme genes, their expression in several hosts, and their modifications; and 2) processing of waste PET to readily biodegradable forms. Finally, the outlook of PET biorecycling is described.
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Affiliation(s)
- Fusako Kawai
- Graduate School of Life and Environmental Sciences, Kyoto Prefectural University, Kyoto, Japan
- Graduate School of Environmental and Life Science, Okayama University, Okayama, Japan
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Carr CM, Clarke DJ, Dobson ADW. Microbial Polyethylene Terephthalate Hydrolases: Current and Future Perspectives. Front Microbiol 2020; 11:571265. [PMID: 33262744 PMCID: PMC7686037 DOI: 10.3389/fmicb.2020.571265] [Citation(s) in RCA: 53] [Impact Index Per Article: 13.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2020] [Accepted: 10/19/2020] [Indexed: 12/18/2022] Open
Abstract
Plastic has rapidly transformed our world, with many aspects of human life now relying on a variety of plastic materials. Biological plastic degradation, which employs microorganisms and their degradative enzymes, has emerged as one way to address the unforeseen consequences of the waste streams that have resulted from mass plastic production. The focus of this review is microbial hydrolase enzymes which have been found to act on polyethylene terephthalate (PET) plastic. The best characterized examples are discussed together with the use of genomic and protein engineering technologies to obtain PET hydrolase enzymes for different applications. In addition, the obstacles which are currently limiting the development of efficient PET bioprocessing are presented. By continuing to study the possible mechanisms and the structural elements of key enzymes involved in microbial PET hydrolysis, and by assessing the ability of PET hydrolase enzymes to work under practical conditions, this research will help inform large-scale waste management operations. Finally, the contribution of microbial PET hydrolases in creating a potential circular PET economy will be explored. This review combines the current knowledge on enzymatic PET processing with proposed strategies for optimization and use, to help clarify the next steps in addressing pollution by PET and other plastics.
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Affiliation(s)
- Clodagh M. Carr
- School of Microbiology, University College Cork, Cork, Ireland
| | - David J. Clarke
- School of Microbiology, University College Cork, Cork, Ireland
| | - Alan D. W. Dobson
- School of Microbiology, University College Cork, Cork, Ireland
- SSPC-SFI Research Centre for Pharmaceuticals, University College Cork, Cork, Ireland
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Pellis A, Vastano M, Quartinello F, Herrero Acero E, Guebitz GM. His-Tag Immobilization of Cutinase 1 From Thermobifida cellulosilytica for Solvent-Free Synthesis of Polyesters. Biotechnol J 2017; 12. [PMID: 28731627 DOI: 10.1002/biot.201700322] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2017] [Revised: 06/26/2017] [Indexed: 11/06/2022]
Abstract
For many years, lipase B from Candida antarctica (CaLB) was the primary biocatalyst used for enzymatic esterification and polycondensation reactions. More recently, the need for novel biocatalysts with different selectivity has arisen in the biotechnology and biocatalysis fields. The present work describes how the catalytic potential of Thermobifida cellulosilytica cutinase 1 (Thc_Cut1) was exploited for polyester synthesis. In a first step, Thc_Cut1 was immobilized on three different carriers, namely Opal, Coral, and Amber, using a novel non-toxic His-tag method based on chelated Fe(III) ions (>99% protein bounded). In a second step, the biocatalyzed synthesis of an array of aliphatic polyesters was conducted. A selectivity chain study in a solvent-free reaction environment showed how, in contrast to CaLB, Thc_Cut1 presents a certain preference for C6 -C4 ester-diol combinations reaching monomer conversions up to 78% and Mw of 878 g mol-1 when the Amber immobilized Thc_Cut1 was used. The synthetic potential of this cutinase was also tested in organic solvents, showing a marked activity decrease in polar media like that observed for CaLB. Finally, recyclability studies were performed, which showed an excellent stability of the immobilized Thc_Cut1 (retained activity >94%) over 24 h reaction cycles when a solvent-free workup was used. Concerning a practical application of the biocatalyst's preparation, the production of oligomers with Mn values below 10 kDa is usually desired for the production of nanoparticles and for the synthesis of functional pre-polymers for coating applications that can be crosslinked in a second reaction step.
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Affiliation(s)
- Alessandro Pellis
- Institute for Environmental Biotechnology, University of Natural Resources and Life Sciences Vienna (BOKU), Konrad Lorenz Strasse 20, 3430, Tulln an der Donau, Austria
| | - Marco Vastano
- Institute for Environmental Biotechnology, University of Natural Resources and Life Sciences Vienna (BOKU), Konrad Lorenz Strasse 20, 3430, Tulln an der Donau, Austria.,Dipartimento di Scienze Chimiche, Universita degli Studi di Napoli Federico II, Via Cinthia 4, 80126, Napoli, Italy
| | - Felice Quartinello
- Institute for Environmental Biotechnology, University of Natural Resources and Life Sciences Vienna (BOKU), Konrad Lorenz Strasse 20, 3430, Tulln an der Donau, Austria
| | - Enrique Herrero Acero
- Division Enzymes & Polymers, Austrian Centre of Industrial Biotechnology GmbH (ACIB), Konrad Lorenz Strasse 20, 3430, Tulln an der Donau, Austria
| | - Georg M Guebitz
- Institute for Environmental Biotechnology, University of Natural Resources and Life Sciences Vienna (BOKU), Konrad Lorenz Strasse 20, 3430, Tulln an der Donau, Austria.,Division Enzymes & Polymers, Austrian Centre of Industrial Biotechnology GmbH (ACIB), Konrad Lorenz Strasse 20, 3430, Tulln an der Donau, Austria
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Chen Y, Black DS, Reilly PJ. Carboxylic ester hydrolases: Classification and database derived from their primary, secondary, and tertiary structures. Protein Sci 2016; 25:1942-1953. [PMID: 27530203 PMCID: PMC5079261 DOI: 10.1002/pro.3016] [Citation(s) in RCA: 35] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2016] [Accepted: 08/12/2016] [Indexed: 11/05/2022]
Abstract
We classified the carboxylic ester hydrolases (CEHs) into families and clans by use of multiple sequence alignments, secondary structure analysis, and tertiary structure superpositions. Our work for the first time has fully established their systematic structural classification. Family members have similar primary, secondary, and tertiary structures, and their active sites and reaction mechanisms are conserved. Families may be gathered into clans by their having similar secondary and tertiary structures, even though primary structures of members of different families are not similar. CEHs were gathered from public databases by use of Basic Local Alignment Search Tool (BLAST) and divided into 91 families, with 36 families being grouped into five clans. Members of one clan have standard α/β-hydrolase folds, while those of other two clans have similar folds but with different sequences of their β-strands. The other two clans have members with six-bladed β-propeller and three-α-helix bundle tertiary structures. Those families not in clans have a large variety of structures or have no members with known structures. At the time of writing, the 91 families contained 321,830 primary structures and 1378 tertiary structures. From these data, we constructed an accessible database: CASTLE (CArboxylic eSTer hydroLasEs, http://www.castle.cbe.iastate.edu).
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Affiliation(s)
- Yingfei Chen
- Department of Chemical and Biological Engineering, Iowa State University, Ames, Iowa, 50011
| | - Daniel S Black
- Information Technology Services, Iowa State University, Ames, Iowa, 50011
| | - Peter J Reilly
- Department of Chemical and Biological Engineering, Iowa State University, Ames, Iowa, 50011.
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