1
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Zhang W, Han Y, Yang F, Guan L, Lu F, Mao S, Tian K, Yao M, Qin HM. A customized self-assembled synergistic biocatalyst for plastic depolymerization. JOURNAL OF HAZARDOUS MATERIALS 2024; 477:135380. [PMID: 39088944 DOI: 10.1016/j.jhazmat.2024.135380] [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: 06/17/2024] [Revised: 07/26/2024] [Accepted: 07/29/2024] [Indexed: 08/03/2024]
Abstract
The enzymatic degradation of plastic offers a green, sustainable strategy and scalable circular carbon route for solving polyester waste. Among the earlies discovered plastic-degrading enzymes are PET hydrolase (PETase) and MHET hydrolase (MHETase), which act synergistically. To promote the adsorption of enzymes on PET surfaces, increase their robustness, and enable directly depolymerization, we designed hydrophobin HFBI fused-PETase and MHETase. A customized self-assembled synergistic biocatalyst (MC@CaZn-MOF) was further developed to promote the two-step depolymerization process. The tailored catalysts showed better adhesion to the PET surface and desirable durability, retaining over 70% relative activity after incubation at pH 8.0 and 60 °C for 120 h. Importantly, MC@CaZn-MOF could directly decompose untreated AGf-PET to generate 9.5 mM TPA with weight loss over 90%. The successful implementation of a bifunctional customized catalyst makes the large-scale biocatalytic degradation of PET feasible, contributing to polymer upcycling and environmental sustainability.
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Affiliation(s)
- Wei Zhang
- Key Laboratory of Industrial Fermentation Microbiology of the Ministry of Education; Tianjin Key Laboratory of Industrial Microbiology, College of Biotechnology, Tianjin University of Science and Technology; National Engineering Laboratory for Industrial Enzymes, Tianjin 300457, China
| | - Yuying Han
- Key Laboratory of Industrial Fermentation Microbiology of the Ministry of Education; Tianjin Key Laboratory of Industrial Microbiology, College of Biotechnology, Tianjin University of Science and Technology; National Engineering Laboratory for Industrial Enzymes, Tianjin 300457, China
| | - Feng Yang
- Key Laboratory of Industrial Fermentation Microbiology of the Ministry of Education; Tianjin Key Laboratory of Industrial Microbiology, College of Biotechnology, Tianjin University of Science and Technology; National Engineering Laboratory for Industrial Enzymes, Tianjin 300457, China
| | - Lijun Guan
- Institute of Food Processing, Heilongjiang Academy of Agricultural Sciences, Harbin, China
| | - Fuping Lu
- Key Laboratory of Industrial Fermentation Microbiology of the Ministry of Education; Tianjin Key Laboratory of Industrial Microbiology, College of Biotechnology, Tianjin University of Science and Technology; National Engineering Laboratory for Industrial Enzymes, Tianjin 300457, China
| | - Shuhong Mao
- Key Laboratory of Industrial Fermentation Microbiology of the Ministry of Education; Tianjin Key Laboratory of Industrial Microbiology, College of Biotechnology, Tianjin University of Science and Technology; National Engineering Laboratory for Industrial Enzymes, Tianjin 300457, China
| | - Kangming Tian
- Key Laboratory of Industrial Fermentation Microbiology of the Ministry of Education; Tianjin Key Laboratory of Industrial Microbiology, College of Biotechnology, Tianjin University of Science and Technology; National Engineering Laboratory for Industrial Enzymes, Tianjin 300457, China.
| | - Mingdong Yao
- Key Laboratory of Systems Bioengineering (Ministry of Education); School of Chemical Engineering and Technology, Tianjin University, Tianjin 300072, China.
| | - Hui-Min Qin
- Key Laboratory of Industrial Fermentation Microbiology of the Ministry of Education; Tianjin Key Laboratory of Industrial Microbiology, College of Biotechnology, Tianjin University of Science and Technology; National Engineering Laboratory for Industrial Enzymes, Tianjin 300457, China.
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2
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Aer L, Jiang Q, Zhong L, Si Q, Liu X, Pan Y, Feng J, Zeng H, Tang L. Optimization of polyethylene terephthalate biodegradation using a self-assembled multi-enzyme cascade strategy. JOURNAL OF HAZARDOUS MATERIALS 2024; 476:134887. [PMID: 38901251 DOI: 10.1016/j.jhazmat.2024.134887] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/04/2024] [Revised: 06/04/2024] [Accepted: 06/10/2024] [Indexed: 06/22/2024]
Abstract
Although many efforts have been devoted to the modification of polyethylene terephthalate (PET) hydrolases for improving the efficiency of PET degradation, the catalytic performance of these enzymes at near-ambient temperatures remains a challenge. Herein, a multi-enzyme cascade system (PT-EC) was developed and validated by assembling three well-developed PETases, PETaseEHA, Fast-PETase, and Z1-PETase, respectively, together with carboxylesterase TfCa, and hydrophobic binding module CBM3a using scaffold proteins. The resulting PT-ECEHA, PT-ECFPE, PT-ECZPE all demonstrated outstanding PET degradation efficacy. Notably, PT-ECEHA exhibited a 16.5-fold increase in product release compared to PETaseEHA, and PT-ECZPE yielded the highest amount of product. Subsequently, PT-ECs were displayed on the surface of Escherichia coli, respectively, and their degradation efficiency toward three PET types was investigated. The displayed PT-ECEHA exhibited a 20-fold increase in degradation efficiency with PET film compared to the surface-displayed PETaseEHA. Remarkably, an almost linear increase in product release was observed for the displayed PT-ECZPE over a one-week degradation period, reaching 11.56 ± 0.64 mM after 7 days. TfCaI69W/L281Y evolved using a docking-based virtual screening strategy showed a further 2.5-fold increase in the product release of PET degradation. Collectively, these advantages of PT-EC demonstrated the potential of a multi-enzyme cascade system for PET bio-cycling.
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Affiliation(s)
- Lizhu Aer
- School of Life Science and Technology, University of Electronic Science and Technology of China, Chengdu 610054, China
| | - Qifa Jiang
- School of Life Science and Technology, University of Electronic Science and Technology of China, Chengdu 610054, China
| | - Linling Zhong
- School of Life Science and Technology, University of Electronic Science and Technology of China, Chengdu 610054, China
| | - Qiuyue Si
- School of Life Science and Technology, University of Electronic Science and Technology of China, Chengdu 610054, China
| | - Xianghong Liu
- School of Life Science and Technology, University of Electronic Science and Technology of China, Chengdu 610054, China
| | - Yan Pan
- Medical School of University of Electronic Science and Technology of China, Chengdu 610054, China
| | - Juan Feng
- School of Life Science and Technology, University of Electronic Science and Technology of China, Chengdu 610054, China; Center for Informational Biology, University of Electronic Science and Technology of China, Chengdu 610054, China
| | - Hongjuan Zeng
- School of Life Science and Technology, University of Electronic Science and Technology of China, Chengdu 610054, China; Center for Informational Biology, University of Electronic Science and Technology of China, Chengdu 610054, China
| | - Lixia Tang
- School of Life Science and Technology, University of Electronic Science and Technology of China, Chengdu 610054, China; Center for Informational Biology, University of Electronic Science and Technology of China, Chengdu 610054, China.
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3
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Du M, Xue R, Yuan W, Cheng Y, Cui Z, Dong W, Qiu B. Tandem Integration of Biological and Electrochemical Catalysis for Efficient Polyester Upcycling under Ambient Conditions. NANO LETTERS 2024; 24:9768-9775. [PMID: 39057181 DOI: 10.1021/acs.nanolett.4c02966] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/28/2024]
Abstract
Excessive production of waste polyethylene terephthalate (PET) poses an ecological challenge, which necessitates developing technologies to extract the values from end-of-life PET. Upcycling has proven effective in addressing the low profitability of current recycling strategies, yet existing upcycling technologies operate under energy-intensive conditions. Here we report a cascade strategy to steer the transformation of PET waste into glycolate in an overall yield of 92.6% under ambient conditions. The cascade approach involves setting up a robust hydrolase with 95.6% PET depolymerization into ethylene glycol (EG) monomer within 12 h, followed by an electrochemical process initiated by a CO-tolerant Pd/Ni(OH)2 catalyst to convert the EG intermediate into glycolate with high Faradaic efficiency of 97.5%. Techno-economic analysis and life cycle assessment indicate that, compared with the widely adopted electrochemical technology that heavily relies on alkaline pretreatment for PET depolymerization, our designed enzymatic-electrochemical approach offers a cost-effective and low-carbon pathway to upgrade PET.
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Affiliation(s)
- Mengmeng Du
- Jiangsu Key Laboratory of Pesticide Sciences, Department of Chemistry, College of Sciences, Nanjing Agricultural University, Nanjing 210095, China
| | - Rui Xue
- College of Biotechnology and Pharmaceutical Engineering, State Key Laboratory of Materials-Oriented Chemical Engineering, Nanjing Tech University, Nanjing 211800, China
| | - Wenfang Yuan
- Jiangsu Key Laboratory of Pesticide Sciences, Department of Chemistry, College of Sciences, Nanjing Agricultural University, Nanjing 210095, China
| | - Yun Cheng
- College of Biotechnology and Pharmaceutical Engineering, State Key Laboratory of Materials-Oriented Chemical Engineering, Nanjing Tech University, Nanjing 211800, China
| | - Zhongli Cui
- Key Laboratory of Agricultural Environmental Microbiology, Ministry of Agriculture and Rural Affairs, College of Life Sciences, Nanjing Agricultural University, Nanjing 210095, China
| | - Weiliang Dong
- College of Biotechnology and Pharmaceutical Engineering, State Key Laboratory of Materials-Oriented Chemical Engineering, Nanjing Tech University, Nanjing 211800, China
| | - Bocheng Qiu
- Jiangsu Key Laboratory of Pesticide Sciences, Department of Chemistry, College of Sciences, Nanjing Agricultural University, Nanjing 210095, China
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4
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Wang T, Yang WT, Gong YM, Zhang YK, Fan XX, Wang GC, Lu ZH, Liu F, Liu XH, Zhu YS. Molecular engineering of PETase for efficient PET biodegradation. ECOTOXICOLOGY AND ENVIRONMENTAL SAFETY 2024; 280:116540. [PMID: 38833982 DOI: 10.1016/j.ecoenv.2024.116540] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/23/2024] [Revised: 05/29/2024] [Accepted: 05/31/2024] [Indexed: 06/06/2024]
Abstract
The widespread utilization of polyethylene terephthalate (PET) has caused a variety of environmental and health problems. Compared with traditional thermomechanical or chemical PET cycling, the biodegradation of PET may offer a more feasible solution. Though the PETase from Ideonalla sakaiensis (IsPETase) displays interesting PET degrading performance under mild conditions; the relatively low thermal stability of IsPETase limits its practical application. In this study, enzyme-catalysed PET degradation was investigated with the promising IsPETase mutant HotPETase (HP). On this basis, a carbohydrate-binding module from Bacillus anthracis (BaCBM) was fused to the C-terminus of HP to construct the PETase mutant (HLCB) for increased PET degradation. Furthermore, to effectively improve PET accessibility and PET-degrading activity, the truncated outer membrane hybrid protein (FadL) was used to expose PETase and BaCBM on the surface of E. coli (BL21with) to develop regenerable whole-cell biocatalysts (D-HLCB). Results showed that, among the tested small-molecular weight ester compounds (p-nitrophenyl phosphate (pNPP), p-Nitrophenyl acetate (pNPA), 4-Nitrophenyl butyrate (pNPB)), PETase displayed the highest hydrolysing activity against pNPP. HP displayed the highest catalytic activity (1.94 μM(p-NP)/min) at 50 °C and increased longevity at 40 °C. The fused BaCBM could clearly improve the catalytic performance of PETase by increasing the optimal reaction temperature and improving the thermostability. When HLCB was used for PET degradation, the yield of monomeric products (255.7 μM) was ∼25.5 % greater than that obtained after 50 h of HP-catalysed PET degradation. Moreover, the highest yield of monomeric products from the D-HLCB-mediated system reached 1.03 mM. The whole-cell catalyst D-HLCB displayed good reusability and stability and could maintain more than 54.6 % of its initial activity for nine cycles. Finally, molecular docking simulations were utilized to investigate the binding mechanism and the reaction mechanism of HLCB, which may provide theoretical evidence to further increase the PET-degrading activities of PETases through rational design. The proposed strategy and developed variants show potential for achieving complete biodegradation of PET under mild conditions.
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Affiliation(s)
- Tao Wang
- School of Biological Science, Jining Medical University, Jining, China
| | - Wen-Tao Yang
- School of Biological Science, Jining Medical University, Jining, China
| | - Yu-Ming Gong
- School of Biological Science, Jining Medical University, Jining, China
| | - Ying-Kang Zhang
- School of Biological Science, Jining Medical University, Jining, China
| | - Xin-Xin Fan
- School of Biological Science, Jining Medical University, Jining, China
| | - Guo-Cheng Wang
- School of Biological Science, Jining Medical University, Jining, China
| | - Zhen-Hua Lu
- College of Chemical and Biological Engineering, Zhejiang University, Hangzhou 310027, China
| | - Fei Liu
- School of Biological Science, Jining Medical University, Jining, China
| | - Xiao-Huan Liu
- School of Biological Science, Jining Medical University, Jining, China
| | - You-Shuang Zhu
- School of Biological Science, Jining Medical University, Jining, China.
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5
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Klauer RR, Hansen DA, Wu D, Monteiro LMO, Solomon KV, Blenner MA. Biological Upcycling of Plastics Waste. Annu Rev Chem Biomol Eng 2024; 15:315-342. [PMID: 38621232 DOI: 10.1146/annurev-chembioeng-100522-115850] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/17/2024]
Abstract
Plastic wastes accumulate in the environment, impacting wildlife and human health and representing a significant pool of inexpensive waste carbon that could form feedstock for the sustainable production of commodity chemicals, monomers, and specialty chemicals. Current mechanical recycling technologies are not economically attractive due to the lower-quality plastics that are produced in each iteration. Thus, the development of a plastics economy requires a solution that can deconstruct plastics and generate value from the deconstruction products. Biological systems can provide such value by allowing for the processing of mixed plastics waste streams via enzymatic specificity and using engineered metabolic pathways to produce upcycling targets. We focus on the use of biological systems for waste plastics deconstruction and upcycling. We highlight documented and predicted mechanisms through which plastics are biologically deconstructed and assimilated and provide examples of upcycled products from biological systems. Additionally, we detail current challenges in the field, including the discovery and development of microorganisms and enzymes for deconstructing non-polyethylene terephthalate plastics, the selection of appropriate target molecules to incentivize development of a plastic bioeconomy, and the selection of microbial chassis for the valorization of deconstruction products.
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Affiliation(s)
- Ross R Klauer
- Department of Chemical and Biomolecular Engineering, University of Delaware, Newark, Delaware, USA; ,
| | - D Alex Hansen
- Department of Chemical and Biomolecular Engineering, University of Delaware, Newark, Delaware, USA; ,
| | - Derek Wu
- Department of Chemical and Biomolecular Engineering, University of Delaware, Newark, Delaware, USA; ,
| | | | - Kevin V Solomon
- Department of Chemical and Biomolecular Engineering, University of Delaware, Newark, Delaware, USA; ,
| | - Mark A Blenner
- Department of Chemical and Biomolecular Engineering, University of Delaware, Newark, Delaware, USA; ,
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6
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Tanaka S, Koga M, Kuragano T, Ogawa A, Ogiwara H, Sato K, Nakajima Y. Depolymerization of Polyester Fibers with Dimethyl Carbonate-Aided Methanolysis. ACS MATERIALS AU 2024; 4:335-345. [PMID: 38737120 PMCID: PMC11083123 DOI: 10.1021/acsmaterialsau.3c00091] [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: 10/26/2023] [Revised: 02/09/2024] [Accepted: 02/12/2024] [Indexed: 05/14/2024]
Abstract
Polyester fibers, comprising mostly poly(ethylene terephthalate) with high crystalline content, represent the most commonly produced plastic for ubiquitous textiles, and approximately 60 million tons are manufactured annually worldwide. Considering the social issues of mismanaged waste produced from used textile products, there is an urgent demand for sustainable waste polyester fiber recycling methods. We developed a low-temperature, rapid, and efficient depolymerization method for recycling polyester fibers. By utilizing methanolysis with dimethyl carbonate as a trapping agent for ethylene glycol, depolymerization of polyester fibers from textile products proceeded at 50 °C for 2 h, affording dimethyl terephthalate (DMT) in a >90% yield. This strategy allowed us to depolymerize even practical polyester textiles blended with other fibers to selectively isolate DMT in high yields. This method was also applicable for colored polyester textiles, and analytically pure DMT was isolated via depolymerization and decolorization processes.
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Affiliation(s)
- Shinji Tanaka
- Interdisciplinary
Research Center for Catalytic Chemistry, National Institute of Advanced Industrial Science and Technology
(AIST), 1-1-1 Higashi, Tsukuba, Ibaraki 305-8565, Japan
| | - Maito Koga
- Research
Institute for Sustainable Chemistry, National
Institute of Advanced Industrial Science and Technology (AIST), 1-1-1 Higashi, Tsukuba, Ibaraki 305-8565, Japan
| | - Takashi Kuragano
- Interdisciplinary
Research Center for Catalytic Chemistry, National Institute of Advanced Industrial Science and Technology
(AIST), 1-1-1 Higashi, Tsukuba, Ibaraki 305-8565, Japan
| | - Atsuko Ogawa
- Interdisciplinary
Research Center for Catalytic Chemistry, National Institute of Advanced Industrial Science and Technology
(AIST), 1-1-1 Higashi, Tsukuba, Ibaraki 305-8565, Japan
| | - Hibiki Ogiwara
- Interdisciplinary
Research Center for Catalytic Chemistry, National Institute of Advanced Industrial Science and Technology
(AIST), 1-1-1 Higashi, Tsukuba, Ibaraki 305-8565, Japan
| | - Kazuhiko Sato
- Interdisciplinary
Research Center for Catalytic Chemistry, National Institute of Advanced Industrial Science and Technology
(AIST), 1-1-1 Higashi, Tsukuba, Ibaraki 305-8565, Japan
| | - Yumiko Nakajima
- Interdisciplinary
Research Center for Catalytic Chemistry, National Institute of Advanced Industrial Science and Technology
(AIST), 1-1-1 Higashi, Tsukuba, Ibaraki 305-8565, Japan
- School
of Materials and Chemical Technology, Tokyo
Institute of Technology, 2-12-1, Ookayama, Meguro-ku, Tokyo 152-8552, Japan
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7
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O’Riordan N, Jurić V, O’Neill SK, Roche AP, Young PW. A Yeast Modular Cloning (MoClo) Toolkit Expansion for Optimization of Heterologous Protein Secretion and Surface Display in Saccharomyces cerevisiae. ACS Synth Biol 2024; 13:1246-1258. [PMID: 38483353 PMCID: PMC11036508 DOI: 10.1021/acssynbio.3c00743] [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: 12/12/2023] [Revised: 02/26/2024] [Accepted: 02/27/2024] [Indexed: 04/20/2024]
Abstract
Saccharomyces cerevisiae is an attractive host for the expression of secreted proteins in a biotechnology context. Unfortunately, many heterologous proteins fail to enter, or efficiently progress through, the secretory pathway, resulting in poor yields. Similarly, yeast surface display has become a widely used technique in protein engineering but achieving sufficient levels of surface expression of recombinant proteins is often challenging. Signal peptides (SPs) and translational fusion partners (TFPs) can be used to direct heterologous proteins through the yeast secretory pathway, however, selection of the optimal secretion promoting sequence is largely a process of trial and error. The yeast modular cloning (MoClo) toolkit utilizes type IIS restriction enzymes to facilitate an efficient assembly of expression vectors from standardized parts. We have expanded this toolkit to enable the efficient incorporation of a panel of 16 well-characterized SPs and TFPs and five surface display anchor proteins into S. cerevisiae expression cassettes. The secretion promoting signals are validated by using five different proteins of interest. Comparison of intracellular and secreted protein levels reveals the optimal secretion promoting sequence for each individual protein. Large, protein of interest-specific variations in secretion efficiency are observed. SP sequences are also used with the five surface display anchors, and the combination of SP and anchor protein proves critical for efficient surface display. These observations highlight the value of the described panel of MoClo compatible parts to allow facile screening of SPs and TFPs and anchor proteins for optimal secretion and/or surface display of a given protein of interest in S. cerevisiae.
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Affiliation(s)
- Nicola
M. O’Riordan
- School
of Biochemistry and Cell Biology, University
College Cork, Cork T12 YN60, Ireland
| | - Vanja Jurić
- School
of Biochemistry and Cell Biology, University
College Cork, Cork T12 YN60, Ireland
- AMBER
Centre, Environmental Research Institute, University College Cork, Cork T23 XE10, Ireland
| | - Sarah K. O’Neill
- School
of Biochemistry and Cell Biology, University
College Cork, Cork T12 YN60, Ireland
| | - Aoife P. Roche
- School
of Biochemistry and Cell Biology, University
College Cork, Cork T12 YN60, Ireland
| | - Paul W. Young
- School
of Biochemistry and Cell Biology, University
College Cork, Cork T12 YN60, Ireland
- AMBER
Centre, Environmental Research Institute, University College Cork, Cork T23 XE10, Ireland
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8
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Zhang L, Tan L, Liu M, Chen Y, Yang Y, Zhang Y, Zhao G. Quantitative measurement of cell-surface displayed proteins based on split-GFP assembly. Microb Cell Fact 2024; 23:108. [PMID: 38609965 PMCID: PMC11015686 DOI: 10.1186/s12934-024-02386-1] [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: 01/12/2024] [Accepted: 04/04/2024] [Indexed: 04/14/2024] Open
Abstract
BACKGROUND Microbial cell surface display technology allows immobilizing proteins on the cell surface by fusing them to anchoring motifs, thereby endowing the cells with diverse functionalities. However, the assessment of successful protein display and the quantification of displayed proteins remain challenging. The green fluorescent protein (GFP) can be split into two non-fluorescent fragments, while they spontaneously assemble and emit fluorescence when brought together through complementation. Based on split-GFP assembly, we aim to: (1) confirm the success display of passenger proteins, (2) quantify the number of passenger proteins displayed on individual cells. RESULTS In this study, we propose two innovative methods based on split-green fluorescent protein (split-GFP), named GFP1-10/GFP11 and GFP1-9/GFP10-11 assembly, for the purpose of confirming successful display and quantifying the number of proteins displayed on individual cells. We evaluated the display efficiency of SUMO and ubiquitin using different anchor proteins to demonstrate the feasibility of the two split-GFP assembly systems. To measure the display efficiency of functional proteins, laccase expression was measured using the split-GFP assembly system by co-displaying GFP11 or GFP10-11 tags, respectively. CONCLUSIONS Our study provides two split-GFP based methods that enable qualitative and quantitative analyses of individual cell display efficiency with a simple workflow, thus facilitating further comprehensive investigations into microbial cell surface display technology. Both split-GFP assembly systems offer a one-step procedure with minimal cost, simplifying the fluorescence analysis of surface-displaying cells.
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Affiliation(s)
- Li Zhang
- Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin, 300308, China
- School of Minerals Processing and Bioengineering, Central South University, Changsha, Hunan, 410083, PR China
| | - Ling Tan
- Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin, 300308, China
- Haihe Laboratory of Synthetic Biology, Tianjin, 300308, China
| | - Meizi Liu
- Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin, 300308, China
- Haihe Laboratory of Synthetic Biology, Tianjin, 300308, China
| | - Yunhong Chen
- Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin, 300308, China
- National Center of Technology Innovation for Synthetic Biology, Tianjin, 300308, China
| | - Yu Yang
- School of Minerals Processing and Bioengineering, Central South University, Changsha, Hunan, 410083, PR China.
| | - Yanfei Zhang
- Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin, 300308, China.
- National Center of Technology Innovation for Synthetic Biology, Tianjin, 300308, China.
| | - Guoping Zhao
- National Center of Technology Innovation for Synthetic Biology, Tianjin, 300308, China
- CAS-Key Laboratory of Synthetic Biology, CAS Center for Excellence in Molecular Plant Sciences, Institute of Plant Physiology and Ecology, Chinese Academy of Sciences, Shanghai, 200032, China
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9
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Weiland F, Kohlstedt M, Wittmann C. Biobased de novo synthesis, upcycling, and recycling - the heartbeat toward a green and sustainable polyethylene terephthalate industry. Curr Opin Biotechnol 2024; 86:103079. [PMID: 38422776 DOI: 10.1016/j.copbio.2024.103079] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2023] [Revised: 01/19/2024] [Accepted: 01/24/2024] [Indexed: 03/02/2024]
Abstract
Polyethylene terephthalate (PET) has revolutionized the industrial sector because of its versatility, with its predominant uses in the textiles and packaging materials industries. Despite the various advantages of this polymer, its synthesis is, unfavorably, tightly intertwined with nonrenewable fossil resources. Additionally, given its widespread use, accumulating PET waste poses a significant environmental challenge. As a result, current research in the areas of biological recycling, upcycling, and de novo synthesis is intensifying. Biological recycling involves the use of micro-organisms or enzymes to breakdown PET into monomers, offering a sustainable alternative to traditional recycling. Upcycling transforms PET waste into value-added products, expanding its potential application range and promoting a circular economy. Moreover, studies of cascading biological and chemical processes driven by microbial cell factories have explored generating PET using renewable, biobased feedstocks such as lignin. These avenues of research promise to mitigate the environmental footprint of PET, underlining the importance of sustainable innovations in the industry.
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Affiliation(s)
- Fabia Weiland
- Institute of Systems Biotechnology, Saarland University, Germany
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10
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Choi J, Kim H, Ahn YR, Kim M, Yu S, Kim N, Lim SY, Park JA, Ha SJ, Lim KS, Kim HO. Recent advances in microbial and enzymatic engineering for the biodegradation of micro- and nanoplastics. RSC Adv 2024; 14:9943-9966. [PMID: 38528920 PMCID: PMC10961967 DOI: 10.1039/d4ra00844h] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2024] [Accepted: 03/19/2024] [Indexed: 03/27/2024] Open
Abstract
This review examines the escalating issue of plastic pollution, specifically highlighting the detrimental effects on the environment and human health caused by microplastics and nanoplastics. The extensive use of synthetic polymers such as polyethylene (PE), polyethylene terephthalate (PET), and polystyrene (PS) has raised significant environmental concerns because of their long-lasting and non-degradable characteristics. This review delves into the role of enzymatic and microbial strategies in breaking down these polymers, showcasing recent advancements in the field. The intricacies of enzymatic degradation are thoroughly examined, including the effectiveness of enzymes such as PETase and MHETase, as well as the contribution of microbial pathways in breaking down resilient polymers into more benign substances. The paper also discusses the impact of chemical composition on plastic degradation kinetics and emphasizes the need for an approach to managing the environmental impact of synthetic polymers. The review highlights the significance of comprehending the physical characteristics and long-term impacts of micro- and nanoplastics in different ecosystems. Furthermore, it points out the environmental and health consequences of these contaminants, such as their ability to cause cancer and interfere with the endocrine system. The paper emphasizes the need for advanced analytical methods and effective strategies for enzymatic degradation, as well as continued research and development in this area. This review highlights the crucial role of enzymatic and microbial strategies in addressing plastic pollution and proposes methods to create effective and environmentally friendly solutions.
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Affiliation(s)
- Jaewon Choi
- Division of Chemical Engineering and Bioengineering, College of Art, Culture and Engineering, Kangwon National University Chuncheon Korea
- Department of Smart Health Science and Technology, Kangwon National University Chuncheon Korea
| | - Hongbin Kim
- Division of Chemical Engineering and Bioengineering, College of Art, Culture and Engineering, Kangwon National University Chuncheon Korea
- Department of Smart Health Science and Technology, Kangwon National University Chuncheon Korea
| | - Yu-Rim Ahn
- Division of Chemical Engineering and Bioengineering, College of Art, Culture and Engineering, Kangwon National University Chuncheon Korea
- Department of Smart Health Science and Technology, Kangwon National University Chuncheon Korea
| | - Minse Kim
- Division of Chemical Engineering and Bioengineering, College of Art, Culture and Engineering, Kangwon National University Chuncheon Korea
- Department of Smart Health Science and Technology, Kangwon National University Chuncheon Korea
| | - Seona Yu
- Division of Chemical Engineering and Bioengineering, College of Art, Culture and Engineering, Kangwon National University Chuncheon Korea
- Department of Smart Health Science and Technology, Kangwon National University Chuncheon Korea
| | - Nanhyeon Kim
- Division of Chemical Engineering and Bioengineering, College of Art, Culture and Engineering, Kangwon National University Chuncheon Korea
- Department of Smart Health Science and Technology, Kangwon National University Chuncheon Korea
| | - Su Yeon Lim
- Division of Chemical Engineering and Bioengineering, College of Art, Culture and Engineering, Kangwon National University Chuncheon Korea
- Department of Smart Health Science and Technology, Kangwon National University Chuncheon Korea
| | - Jeong-Ann Park
- Department of Environmental Engineering, Kangwon National University Chuncheon 24341 Republic of Korea
| | - Suk-Jin Ha
- Division of Chemical Engineering and Bioengineering, College of Art, Culture and Engineering, Kangwon National University Chuncheon Korea
- Department of Smart Health Science and Technology, Kangwon National University Chuncheon Korea
| | - Kwang Suk Lim
- Division of Chemical Engineering and Bioengineering, College of Art, Culture and Engineering, Kangwon National University Chuncheon Korea
- Department of Smart Health Science and Technology, Kangwon National University Chuncheon Korea
| | - Hyun-Ouk Kim
- Division of Chemical Engineering and Bioengineering, College of Art, Culture and Engineering, Kangwon National University Chuncheon Korea
- Department of Smart Health Science and Technology, Kangwon National University Chuncheon Korea
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11
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Oda K, Wlodawer A. Development of Enzyme-Based Approaches for Recycling PET on an Industrial Scale. Biochemistry 2024. [PMID: 38285602 DOI: 10.1021/acs.biochem.3c00554] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2024]
Abstract
Pollution by plastics such as polyethylene (PE), polypropylene (PP), polyvinyl chloride (PVC), polyurethane (PUR), polyamide (PA), polystyrene (PS), and poly(ethylene terephthalate) (PET) is now gaining worldwide attention as a critical environmental issue, closely linked to climate change. Among them, PET is particularly prone to hydrolysis, breaking down into its constituents, ethylene glycol (EG) and terephthalate (TPA). Biorecycling or bioupcycling stands out as one of the most promising methods for addressing PET pollution. For dealing with pollution by the macrosize PET, a French company Carbios has developed a pilot-scale plant for biorecycling waste PET beverage bottles into new bottles using derivatives of thermophilic leaf compost cutinase (LCC). However, this system still provides significant challenges in its practical implementation. For the micro- or nanosize PET pollution that poses significant human health risks, including cancer, no industrial-scale approach has been established so far, despite the need to develop such technologies. In this Perspective, we explore the enhancement of the low activity and thermostability of the enzyme PETase to match that of LCC, along with the potential application of microbes and enzymes for the treatment of waste PET as microplastics. Additionally, we discuss the shortcomings of the current biorecycling protocols from a life cycle assessment perspective, covering aspects such as the diversity of PET-hydrolyzing enzymes in nature, the catalytic mechanism for crystallized PET, and more. We also provide an overview of the Ideonella sakaiensis system, highlighting its ability to operate and grow at moderate temperatures, in contrast to high-temperature processes.
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Affiliation(s)
- Kohei Oda
- Department of Applied Biology, Kyoto Institute of Technology, Matsugasaki, Sakyo-ku, Kyoto 606-8585, Japan
| | - Alexander Wlodawer
- Center for Structural Biology, National Cancer Institute, Frederick, Maryland 21702, United States
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12
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Shi L, Zhu L. Recent Advances and Challenges in Enzymatic Depolymerization and Recycling of PET Wastes. Chembiochem 2024; 25:e202300578. [PMID: 37960968 DOI: 10.1002/cbic.202300578] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2023] [Revised: 11/12/2023] [Accepted: 11/13/2023] [Indexed: 11/15/2023]
Abstract
Poly (ethylene terephthalate) (PET) is one of the most commonly used plastics in daily life and various industries. Enzymatic depolymerization and recycling of post-consumer PET (pc-PET) provides a promising strategy for the sustainable circular economy of polymers. Great protein engineering efforts have been devoted to improving the depolymerization performance of PET hydrolytic enzymes (PHEs). In this review, we first discuss the mechanisms and challenges of enzymatic PET depolymerization. Subsequently, we summarize the state-of-the-art engineering of PHEs including rational design, machine learning, and directed evolution for improved depolymerization performance, and highlight the advances in screening methods of PHEs. We further discuss several factors that affect the enzymatic depolymerization efficiency. We conclude with our perspective on the opportunities and challenges in bio-recycling and bio-upcycling of PET wastes.
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Affiliation(s)
- Lixia Shi
- Key Laboratory of Engineering Biology for Low-Carbon Manufacturing, Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, 32 West 7th Avenue, Tianjin Airport Economic Area, Tianjin, 300308, China
- National Technology Innovation Center of Synthetic Biology, 32 West 7th Avenue, Tianjin Airport Economic Area, Tianjin, 300308, China
| | - Leilei Zhu
- Key Laboratory of Engineering Biology for Low-Carbon Manufacturing, Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, 32 West 7th Avenue, Tianjin Airport Economic Area, Tianjin, 300308, China
- National Technology Innovation Center of Synthetic Biology, 32 West 7th Avenue, Tianjin Airport Economic Area, Tianjin, 300308, China
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13
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Hu J, Chen Y. Constructing Escherichia coli co-display systems for biodegradation of polyethylene terephthalate. BIORESOUR BIOPROCESS 2023; 10:91. [PMID: 38647917 PMCID: PMC10992762 DOI: 10.1186/s40643-023-00711-x] [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: 09/19/2023] [Accepted: 11/25/2023] [Indexed: 04/25/2024] Open
Abstract
BACKGROUND The accumulation of fast-growing polyethylene terephthalate (PET) wastes has posed numerous threats to the environments and human health. Enzymatic degradation of PET is a promising approach for PET waste treatment. Currently, the efficiency of various PET biodegradation systems requires further improvements. RESULTS In this work, we engineered whole cell systems with co-display of strong adhesive proteins and the most active PETase for PET biodegradation in E. coli cells. Adhesive proteins of cp52k and mfp-3 and Fast-PETase were simultaneously displayed on the surfaces of E. coli cells, and the resulting cells displaying mfp-3 showed 50% increase of adhesion ability compared to those without adhesive proteins. Consequently, the degradation rate of E. coli cells co-displaying mfp-3 and Fast-PETase for amorphous PET exceeded 15% within 24 h, exhibiting fast and thorough PET degradation. CONCLUSIONS Through the engineering of co-display systems in E. coli cells, PET degradation efficiency was significantly increased compared to E. coli cells with sole display of Fast-PETase and free enzyme. This feasible E. coli co-display system could be served as a convenient tool for extending the treatment options for PET biodegradation.
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Affiliation(s)
- Jiayu Hu
- Laboratory of Chemical Biology, School of Life Science and Technology, China Pharmaceutical University, Nanjing, 211198, Jiangsu, People's Republic of China
| | - Yijun Chen
- Laboratory of Chemical Biology, School of Life Science and Technology, China Pharmaceutical University, Nanjing, 211198, Jiangsu, People's Republic of China.
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14
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Jiang W, Sun J, Dong W, Zhou J, Jiang Y, Zhang W, Xin F, Jiang M. Characterization of a novel esterase and construction of a Rhodococcus-Burkholderia consortium capable of catabolism bis (2-hydroxyethyl) terephthalate. ENVIRONMENTAL RESEARCH 2023; 238:117240. [PMID: 37783328 DOI: 10.1016/j.envres.2023.117240] [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: 08/11/2023] [Revised: 09/22/2023] [Accepted: 09/25/2023] [Indexed: 10/04/2023]
Abstract
Bis (2-hydroxyethyl) terephthalate (BHET) is one of the main compounds produced by enzymatic hydrolysis or chemical depolymerization of polyethylene terephthalate (PET). However, the lack of understanding on BHET microbial metabolism is a main factor limiting the bio-upcycling of PET. In this study, BHET-degrading strains of Rhodococcus biphenylivorans GA1 and Burkholderia sp. EG1 were isolated and identified, which can grow with BHET as the sole carbon source. Furthermore, a novel esterase gene betH was cloned from strain GA1, which encodes a BHET hydrolyzing esterase with the highest activity at 30 °C and pH 7.0. In addition, the co-culture containing strain GA1 and strain EG1 could completely degrade high concentration of BHET, eliminating the inhibition on strain GA1 caused by the accumulation of intermediate metabolite ethylene glycol (EG). This work will provide potential strains and a feasible strategy for PET bio-upcycling.
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Affiliation(s)
- Wankui Jiang
- State Key Laboratory of Materials-Oriented Chemical Engineering, College of Biotechnology and Pharmaceutical Engineering, Nanjing Tech University, Nanjing, 211816, PR China
| | - Jingxiang Sun
- State Key Laboratory of Materials-Oriented Chemical Engineering, College of Biotechnology and Pharmaceutical Engineering, Nanjing Tech University, Nanjing, 211816, PR China
| | - Weiliang Dong
- State Key Laboratory of Materials-Oriented Chemical Engineering, College of Biotechnology and Pharmaceutical Engineering, Nanjing Tech University, Nanjing, 211816, PR China
| | - Jie Zhou
- State Key Laboratory of Materials-Oriented Chemical Engineering, College of Biotechnology and Pharmaceutical Engineering, Nanjing Tech University, Nanjing, 211816, PR China
| | - Yujia Jiang
- State Key Laboratory of Materials-Oriented Chemical Engineering, College of Biotechnology and Pharmaceutical Engineering, Nanjing Tech University, Nanjing, 211816, PR China
| | - Wenming Zhang
- State Key Laboratory of Materials-Oriented Chemical Engineering, College of Biotechnology and Pharmaceutical Engineering, Nanjing Tech University, Nanjing, 211816, PR China; Jiangsu National Synergetic Innovation Center for Advanced Materials (SICAM), Nanjing Tech University, Nanjing, 211816, PR China.
| | - Fengxue Xin
- State Key Laboratory of Materials-Oriented Chemical Engineering, College of Biotechnology and Pharmaceutical Engineering, Nanjing Tech University, Nanjing, 211816, PR China; Jiangsu National Synergetic Innovation Center for Advanced Materials (SICAM), Nanjing Tech University, Nanjing, 211816, PR China.
| | - Min Jiang
- State Key Laboratory of Materials-Oriented Chemical Engineering, College of Biotechnology and Pharmaceutical Engineering, Nanjing Tech University, Nanjing, 211816, PR China; Jiangsu National Synergetic Innovation Center for Advanced Materials (SICAM), Nanjing Tech University, Nanjing, 211816, PR China
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15
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Jin J, Arciszewski J, Auclair K, Jia Z. Enzymatic polyethylene biorecycling: Confronting challenges and shaping the future. JOURNAL OF HAZARDOUS MATERIALS 2023; 460:132449. [PMID: 37690195 DOI: 10.1016/j.jhazmat.2023.132449] [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: 04/24/2023] [Revised: 08/25/2023] [Accepted: 08/30/2023] [Indexed: 09/12/2023]
Abstract
Polyethylene (PE) is a widely used plastic known for its resistance to biodegradation, posing a significant environmental challenge. Recent advances have shed light on microorganisms and insects capable of breaking down PE and identified potential PE-degrading enzymes (PEases), hinting at the possibility of PE biorecycling. Research on enzymatic PE degradation is still in its early stages, especially compared to the progress made with polyethylene terephthalate (PET). While PET hydrolases have been extensively studied and engineered for improved performance, even the products of PEases remain mostly undefined. This Perspective analyzes the current state of enzymatic PE degradation research, highlighting obstacles in the search for bona fide PEases and suggesting areas for future exploration. A critical challenge impeding progress in this field stems from the inert nature of the C-C and C-H bonds of PE. Furthermore, breaking down PE into small molecules using only one monofunctional enzyme is theoretically impossible. Overcoming these obstacles requires identifying enzymatic pathways, which can be facilitated using emerging technologies like omics, structure-based design, and computer-assisted engineering of enzymes. Understanding the mechanisms underlying PE enzymatic biodegradation is crucial for research progress and for identifying potential solutions to the global plastic pollution crisis.
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Affiliation(s)
- Jin Jin
- Department of Biomedical and Molecular Sciences, Queen's University, 18 Stuart Street, Kingston, ON KL7 3N6, Canada
| | - Jane Arciszewski
- Department of Chemistry, McGill University, 801 Sherbrooke St. West, Montréal QC H3A 0B8, Canada
| | - Karine Auclair
- Department of Chemistry, McGill University, 801 Sherbrooke St. West, Montréal QC H3A 0B8, Canada
| | - Zongchao Jia
- Department of Biomedical and Molecular Sciences, Queen's University, 18 Stuart Street, Kingston, ON KL7 3N6, Canada.
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16
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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.
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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
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17
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Liu F, Wang T, Yang W, Zhang Y, Gong Y, Fan X, Wang G, Lu Z, Wang J. Current advances in the structural biology and molecular engineering of PETase. Front Bioeng Biotechnol 2023; 11:1263996. [PMID: 37795175 PMCID: PMC10546322 DOI: 10.3389/fbioe.2023.1263996] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2023] [Accepted: 08/31/2023] [Indexed: 10/06/2023] Open
Abstract
Poly(ethylene terephthalate) (PET) is a highly useful synthetic polyester plastic that is widely used in daily life. However, the increase in postconsumer PET as plastic waste that is recalcitrant to biodegradation in landfills and the natural environment has raised worldwide concern. Currently, traditional PET recycling processes with thermomechanical or chemical methods also result in the deterioration of the mechanical properties of PET. Therefore, it is urgent to develop more efficient and green strategies to address this problem. Recently, a novel mesophilic PET-degrading enzyme (IsPETase) from Ideonella sakaiensis was found to streamline PET biodegradation at 30°C, albeit with a lower PET-degrading activity than chitinase or chitinase-like PET-degrading enzymes. Consequently, the molecular engineering of more efficient PETases is still required for further industrial applications. This review details current knowledge on IsPETase, MHETase, and IsPETase-like hydrolases, including the structures, ligand‒protein interactions, and rational protein engineering for improved PET-degrading performance. In particular, applications of the engineered catalysts are highlighted, including metabolic engineering of the cell factories, enzyme immobilization or cell surface display. The information is expected to provide novel insights for the biodegradation of complex polymers.
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Affiliation(s)
- Fei Liu
- School of Biological Science, Jining Medical University, Rizhao, China
| | - Tao Wang
- School of Biological Science, Jining Medical University, Rizhao, China
| | - Wentao Yang
- School of Biological Science, Jining Medical University, Rizhao, China
| | - Yingkang Zhang
- School of Biological Science, Jining Medical University, Rizhao, China
| | - Yuming Gong
- School of Biological Science, Jining Medical University, Rizhao, China
| | - Xinxin Fan
- School of Biological Science, Jining Medical University, Rizhao, China
| | - Guocheng Wang
- School of Biological Science, Jining Medical University, Rizhao, China
| | - Zhenhua Lu
- College of Chemical and Biological Engineering, Zhejiang University, Hangzhou, Zhejiang, China
| | - Jianmin Wang
- School of Pharmacy, Jining Medical University, Rizhao, China
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18
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Williams GB, Ma H, Khusnutdinova AN, Yakunin AF, Golyshin PN. Harnessing extremophilic carboxylesterases for applications in polyester depolymerisation and plastic waste recycling. Essays Biochem 2023; 67:715-729. [PMID: 37334661 PMCID: PMC10423841 DOI: 10.1042/ebc20220255] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2023] [Revised: 06/01/2023] [Accepted: 06/05/2023] [Indexed: 06/20/2023]
Abstract
The steady growth in industrial production of synthetic plastics and their limited recycling have resulted in severe environmental pollution and contribute to global warming and oil depletion. Currently, there is an urgent need to develop efficient plastic recycling technologies to prevent further environmental pollution and recover chemical feedstocks for polymer re-synthesis and upcycling in a circular economy. Enzymatic depolymerization of synthetic polyesters by microbial carboxylesterases provides an attractive addition to existing mechanical and chemical recycling technologies due to enzyme specificity, low energy consumption, and mild reaction conditions. Carboxylesterases constitute a diverse group of serine-dependent hydrolases catalysing the cleavage and formation of ester bonds. However, the stability and hydrolytic activity of identified natural esterases towards synthetic polyesters are usually insufficient for applications in industrial polyester recycling. This necessitates further efforts on the discovery of robust enzymes, as well as protein engineering of natural enzymes for enhanced activity and stability. In this essay, we discuss the current knowledge of microbial carboxylesterases that degrade polyesters (polyesterases) with focus on polyethylene terephthalate (PET), which is one of the five major synthetic polymers. Then, we briefly review the recent progress in the discovery and protein engineering of microbial polyesterases, as well as developing enzyme cocktails and secreted protein expression for applications in the depolymerisation of polyester blends and mixed plastics. Future research aimed at the discovery of novel polyesterases from extreme environments and protein engineering for improved performance will aid developing efficient polyester recycling technologies for the circular plastics economy.
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Affiliation(s)
- Gwion B Williams
- Centre for Environmental Biotechnology, School of Natural Sciences, Bangor University, Deiniol Road, Bangor LL57 2UW, U.K
| | - Hairong Ma
- Centre for Environmental Biotechnology, School of Natural Sciences, Bangor University, Deiniol Road, Bangor LL57 2UW, U.K
| | - Anna N Khusnutdinova
- Centre for Environmental Biotechnology, School of Natural Sciences, Bangor University, Deiniol Road, Bangor LL57 2UW, U.K
| | - Alexander F Yakunin
- Centre for Environmental Biotechnology, School of Natural Sciences, Bangor University, Deiniol Road, Bangor LL57 2UW, U.K
| | - Peter N Golyshin
- Centre for Environmental Biotechnology, School of Natural Sciences, Bangor University, Deiniol Road, Bangor LL57 2UW, U.K
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19
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Dong H, Yang X, Shi J, Xiao C, Zhang Y. Exploring the Feasibility of Cell-Free Synthesis as a Platform for Polyhydroxyalkanoate (PHA) Production: Opportunities and Challenges. Polymers (Basel) 2023; 15:polym15102333. [PMID: 37242908 DOI: 10.3390/polym15102333] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2023] [Revised: 05/12/2023] [Accepted: 05/13/2023] [Indexed: 05/28/2023] Open
Abstract
The extensive utilization of traditional petroleum-based plastics has resulted in significant damage to the natural environment and ecological systems, highlighting the urgent need for sustainable alternatives. Polyhydroxyalkanoates (PHAs) have emerged as promising bioplastics that can compete with petroleum-based plastics. However, their production technology currently faces several challenges, primarily focused on high costs. Cell-free biotechnologies have shown significant potential for PHA production; however, despite recent progress, several challenges still need to be overcome. In this review, we focus on the status of cell-free PHA synthesis and compare it with microbial cell-based PHA synthesis in terms of advantages and drawbacks. Finally, we present prospects for the development of cell-free PHA synthesis.
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Affiliation(s)
- Huaming Dong
- School of Environmental Ecology and Biological Engineering, Wuhan Institute of Technology, Wuhan 430205, China
- Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin 300308, China
| | - Xue Yang
- Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin 300308, China
- National Center of Technology Innovation for Synthetic Biology, Tianjin 300308, China
| | - Jingjing Shi
- Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin 300308, China
- National Center of Technology Innovation for Synthetic Biology, Tianjin 300308, China
| | - Chunqiao Xiao
- School of Environmental Ecology and Biological Engineering, Wuhan Institute of Technology, Wuhan 430205, China
| | - Yanfei Zhang
- Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin 300308, China
- National Center of Technology Innovation for Synthetic Biology, Tianjin 300308, China
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20
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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: 9] [Impact Index Per Article: 9.0] [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.
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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.
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21
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Determinants for an Efficient Enzymatic Catalysis in Poly(Ethylene Terephthalate) Degradation. Catalysts 2023. [DOI: 10.3390/catal13030591] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/18/2023] Open
Abstract
The enzymatic degradation of the recalcitrant poly(ethylene terephthalate) (PET) has been an important biotechnological goal. The present review focuses on the state of the art in enzymatic degradation of PET, and the challenges ahead. This review covers (i) enzymes acting on PET, (ii) protein improvements through selection or engineering, (iii) strategies to improve biocatalyst–polymer interaction and monomer yields. Finally, this review discusses critical points on PET degradation, and their related experimental aspects, that include the control of physicochemical parameters. The search for, and engineering of, PET hydrolases, have been widely studied to achieve this, and several examples are discussed here. Many enzymes, from various microbial sources, have been studied and engineered, but recently true PET hydrolases (PETases), active at moderate temperatures, were reported. For a circular economy process, terephtalic acid (TPA) production is critical. Some thermophilic cutinases and engineered PETases have been reported to release terephthalic acid in significant amounts. Some bottlenecks in enzyme performance are discussed, including enzyme activity, thermal stability, substrate accessibility, PET microstructures, high crystallinity, molecular mass, mass transfer, and efficient conversion into reusable fragments.
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22
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Microbial Enzyme Biotechnology to Reach Plastic Waste Circularity: Current Status, Problems and Perspectives. Int J Mol Sci 2023; 24:ijms24043877. [PMID: 36835289 PMCID: PMC9967032 DOI: 10.3390/ijms24043877] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2023] [Revised: 02/08/2023] [Accepted: 02/10/2023] [Indexed: 02/17/2023] Open
Abstract
The accumulation of synthetic plastic waste in the environment has become a global concern. Microbial enzymes (purified or as whole-cell biocatalysts) represent emerging biotechnological tools for waste circularity; they can depolymerize materials into reusable building blocks, but their contribution must be considered within the context of present waste management practices. This review reports on the prospective of biotechnological tools for plastic bio-recycling within the framework of plastic waste management in Europe. Available biotechnology tools can support polyethylene terephthalate (PET) recycling. However, PET represents only ≈7% of unrecycled plastic waste. Polyurethanes, the principal unrecycled waste fraction, together with other thermosets and more recalcitrant thermoplastics (e.g., polyolefins) are the next plausible target for enzyme-based depolymerization, even if this process is currently effective only on ideal polyester-based polymers. To extend the contribution of biotechnology to plastic circularity, optimization of collection and sorting systems should be considered to feed chemoenzymatic technologies for the treatment of more recalcitrant and mixed polymers. In addition, new bio-based technologies with a lower environmental impact in comparison with the present approaches should be developed to depolymerize (available or new) plastic materials, that should be designed for the required durability and for being susceptible to the action of enzymes.
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