1
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Tanaka Y, Hiraga K, Inui M. Regulation of the expression of MHETase and TPA degradation genes involved in the degradation of PET in Ideonella sakaiensis. FEBS J 2024; 291:4489-4500. [PMID: 39110086 DOI: 10.1111/febs.17240] [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: 12/18/2023] [Revised: 05/03/2024] [Accepted: 07/24/2024] [Indexed: 10/17/2024]
Abstract
Ideonella sakaiensis is a bacterium that can degrade and consume polyethylene terephthalate (PET), a plastic material that was previously considered non-biodegradable. The degradation of PET requires two enzymes, namely poly (ethylene terephthalate) hydrolase (PETase) and mono (2-hydroxyethyl) terephthalate hydrolase (MHETase), which break down PET into terephthalate (TPA) and ethylene glycol (EG), which serve as carbon sources for the bacterium. Previous studies have focused on the enzymatic properties, structure, and mechanism of action of PETase and MHETase. However, the regulation of PETase and MHETase gene expression has not been investigated. This study identified a protein that binds to the MHETase promoter DNA, MHETase gene-regulating protein (MRP) in I. sakaiensis. PET or TPA induced the expression of PETase and MHETase genes. Furthermore, the induction of the MHETase gene was abolished by the deletion of the mrp gene, while the expression of the PETase gene was maintained. In addition, the genes involved in TPA metabolism were not induced in the mrp mutant. Furthermore, the growth of the PET and TPA deteriorated due to mrp mutation. Also, MRP binds to the promoter regions of the MHETase gene and TPA metabolizing genes, but not to the PETase gene promoter. These results suggest that MRP is a transcription factor that activates MHETase and TPA-metabolizing genes.
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Affiliation(s)
- Yuya Tanaka
- Research Institute of Innovative Technology for the Earth, Kizugawa, Japan
| | - Kazumi Hiraga
- Graduate School of Science and Technology, Nara Institute of Science and Technology, Ikoma, Japan
| | - Masayuki Inui
- Research Institute of Innovative Technology for the Earth, Kizugawa, Japan
- Graduate School of Science and Technology, Nara Institute of Science and Technology, Ikoma, Japan
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2
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Zhang M, Zhen J, Teng J, Zhao X, Fu X, Song H, Zhang Y, Zheng H, Bai W. N-Terminal Sequences of Signal Peptides Assuming Critical Roles in Expression of Heterologous Proteins in Bacillus subtilis. Microorganisms 2024; 12:1275. [PMID: 39065044 PMCID: PMC11278945 DOI: 10.3390/microorganisms12071275] [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: 04/29/2024] [Revised: 06/19/2024] [Accepted: 06/20/2024] [Indexed: 07/28/2024] Open
Abstract
The N-terminal sequences of proteins and their corresponding encoding sequences may play crucial roles in the heterologous expression. In this study, the secretory expression of alkaline pectin lyase APL in B. subtilis was investigated to explore the effects of the N-terminal 5-7 amino acid sequences of different signal peptides on the protein expression and secretion. It was identified for the first time that the first five amino acid sequences of the N-terminal of the signal peptide (SP-LipA) from Bacillus subtilis lipase A play an important role in promoting the expression of APL. Furthermore, it was revealed that SP-LipA resulted in higher secretory expression compared to other signal peptides in this study primarily due to its encoding of N-terminal amino acids with relatively higher transcription levels and its efficient secretion capacity. Based on this foundation, the recombinant strain constructed in this work achieved a new record for the highest extracellular yields of APL in B. subtilis, reaching 12,295 U/mL, which was 1.9-times higher than that expressed in the recombinant Escherichia coli strain previously reported. The novel theories uncovered in this study are expected to play significant roles in enhancing the expression of foreign proteins both inside and outside of cells.
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Affiliation(s)
- Meijuan Zhang
- College of Life Science and Agriculture Forestry, Qiqihar University, Qiqihar 161006, China;
| | - Jie Zhen
- Industrial Enzymes National Engineering Research Center, Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin 300308, China; (J.Z.)
- National Center of Technology Innovation for Synthetic Biology, Tianjin 300308, China
- Tianjin Key Laboratory for Industrial Biological Systems and Bioprocessing Engineering, Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin 300308, China
| | - Jia Teng
- Industrial Enzymes National Engineering Research Center, Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin 300308, China; (J.Z.)
- College of Food Science and Biotechnology, Tianjin Agricultural University, Tianjin 300392, China;
| | - Xingya Zhao
- Industrial Enzymes National Engineering Research Center, Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin 300308, China; (J.Z.)
- National Center of Technology Innovation for Synthetic Biology, Tianjin 300308, China
| | - Xiaoping Fu
- Industrial Enzymes National Engineering Research Center, Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin 300308, China; (J.Z.)
- National Center of Technology Innovation for Synthetic Biology, Tianjin 300308, China
| | - Hui Song
- Industrial Enzymes National Engineering Research Center, Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin 300308, China; (J.Z.)
- National Center of Technology Innovation for Synthetic Biology, Tianjin 300308, China
- Tianjin Key Laboratory for Industrial Biological Systems and Bioprocessing Engineering, Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin 300308, China
| | - Yeni Zhang
- College of Food Science and Biotechnology, Tianjin Agricultural University, Tianjin 300392, China;
| | - Hongchen Zheng
- Industrial Enzymes National Engineering Research Center, Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin 300308, China; (J.Z.)
- National Center of Technology Innovation for Synthetic Biology, Tianjin 300308, China
- Tianjin Key Laboratory for Industrial Biological Systems and Bioprocessing Engineering, Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin 300308, China
- Key Laboratory of Engineering Biology for Low-Carbon Manufacturing, Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin 300308, China
| | - Wenqin Bai
- Industrial Enzymes National Engineering Research Center, Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin 300308, China; (J.Z.)
- National Center of Technology Innovation for Synthetic Biology, Tianjin 300308, China
- Tianjin Key Laboratory for Industrial Biological Systems and Bioprocessing Engineering, Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin 300308, China
- Key Laboratory of Engineering Biology for Low-Carbon Manufacturing, Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin 300308, China
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3
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Omar MN, Minggu MM, Nor Muhammad NA, Abdul PM, Zhang Y, Ramzi AB. Towards consolidated bioprocessing of biomass and plastic substrates for semi-synthetic production of bio-poly(ethylene furanoate) (PEF) polymer using omics-guided construction of artificial microbial consortia. Enzyme Microb Technol 2024; 177:110429. [PMID: 38537325 DOI: 10.1016/j.enzmictec.2024.110429] [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: 11/28/2023] [Revised: 02/20/2024] [Accepted: 03/14/2024] [Indexed: 04/29/2024]
Abstract
Poly(ethylene furanoate) (PEF) plastic is a 100% renewable polyester that is currently being pursued for commercialization as the next-generation bio-based plastic. This is in line with growing demand for circular bioeconomy and new plastics economy that is aimed at minimizing plastic waste mismanagement and lowering carbon footprint of plastics. However, the current catalytic route for the synthesis of PEF is impeded with technical challenges including high cost of pretreatment and catalyst refurbishment. On the other hand, the semi-biosynthetic route of PEF plastic production is of increased biotechnological interest. In particular, the PEF monomers (Furan dicarboxylic acid and ethylene glycol) can be synthesized via microbial-based biorefinery and purified for subsequent catalyst-mediated polycondensation into PEF. Several bioengineering and bioprocessing issues such as efficient substrate utilization and pathway optimization need to be addressed prior to establishing industrial-scale production of the monomers. This review highlights current advances in semi-biosynthetic production of PEF monomers using consolidated waste biorefinery strategies, with an emphasis on the employment of omics-driven systems biology approaches in enzyme discovery and pathway construction. The roles of microbial protein transporters will be discussed, especially in terms of improving substrate uptake and utilization from lignocellulosic biomass, as well as from depolymerized plastic waste as potential bio-feedstock. The employment of artificial bioengineered microbial consortia will also be highlighted to provide streamlined systems and synthetic biology strategies for bio-based PEF monomer production using both plant biomass and plastic-derived substrates, which are important for circular and new plastics economy advances.
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Affiliation(s)
- Mohd Norfikri Omar
- Institute of Systems Biology (INBIOSIS), Universiti Kebangsaan Malaysia (UKM), UKM, Bangi, Selangor 43600, Malaysia
| | - Matthlessa Matthew Minggu
- Institute of Systems Biology (INBIOSIS), Universiti Kebangsaan Malaysia (UKM), UKM, Bangi, Selangor 43600, Malaysia
| | - Nor Azlan Nor Muhammad
- Institute of Systems Biology (INBIOSIS), Universiti Kebangsaan Malaysia (UKM), UKM, Bangi, Selangor 43600, Malaysia
| | - Peer Mohamed Abdul
- Department of Chemical and Process Engineering, Faculty of Engineering and Built Environment, Universiti Kebangsaan Malaysia, Bangi, Selangor 43600, Malaysia; Centre for Sustainable Process Technology (CESPRO), Faculty of Engineering and Built Environment, Universiti Kebangsaan Malaysia, Bangi, Selangor 43600, Malaysia
| | - Ying Zhang
- BBSRC/EPSRC Synthetic Biology Research Centre (SBRC), School of Life Sciences, University of Nottingham, University Park, Nottingham NG7 2RD, UK
| | - Ahmad Bazli Ramzi
- Institute of Systems Biology (INBIOSIS), Universiti Kebangsaan Malaysia (UKM), UKM, Bangi, Selangor 43600, Malaysia.
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4
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Arif Y, Mir AR, Zieliński P, Hayat S, Bajguz A. Microplastics and nanoplastics: Source, behavior, remediation, and multi-level environmental impact. JOURNAL OF ENVIRONMENTAL MANAGEMENT 2024; 356:120618. [PMID: 38508005 DOI: 10.1016/j.jenvman.2024.120618] [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: 10/23/2023] [Revised: 02/21/2024] [Accepted: 03/10/2024] [Indexed: 03/22/2024]
Abstract
Plastics introduced into the natural environment persist, degrade, and fragment into smaller particles due to various environmental factors. Microplastics (MPs) (ranging from 1 μm to 5 mm) and nanoplastics (NPs) (less than 1 μm) have emerged as pollutants posing a significant threat to all life forms on Earth. Easily ingested by living organisms, they lead to ongoing bioaccumulation and biomagnification. This review summarizes existing studies on the sources of MPs and NPs in various environments, highlighting their widespread presence in air, water, and soil. It primarily focuses on the sources, fate, degradation, fragmentation, transport, and ecotoxicity of MPs and NPs. The aim is to elucidate their harmful effects on marine organisms, soil biota, plants, mammals, and humans, thereby enhancing the understanding of the complex impacts of plastic particles on the environment. Additionally, this review highlights remediation technologies and global legislative and institutional measures for managing waste associated with MPs and NPs. It also shows that effectively combating plastic pollution requires the synergization of diverse management, monitoring strategies, and regulatory measures into a comprehensive policy framework.
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Affiliation(s)
- Yamshi Arif
- Department of Botany, Plant Physiology Section, Faculty of Life Sciences, Aligarh Muslim University, Aligarh, India
| | - Anayat Rasool Mir
- Department of Botany, Plant Physiology Section, Faculty of Life Sciences, Aligarh Muslim University, Aligarh, India
| | - Piotr Zieliński
- Department of Water Ecology, Faculty of Biology, University of Bialystok, Ciolkowskiego 1J, 15-245, Bialystok, Poland
| | - Shamsul Hayat
- Department of Botany, Plant Physiology Section, Faculty of Life Sciences, Aligarh Muslim University, Aligarh, India
| | - Andrzej Bajguz
- Department of Biology and Plant Ecology, Faculty of Biology, University of Bialystok, Ciolkowskiego 1J, 15-245, Bialystok, Poland.
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5
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Zhang Z, Zhang Q, Yang H, Cui L, Qian H. Mining strategies for isolating plastic-degrading microorganisms. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2024; 346:123572. [PMID: 38369095 DOI: 10.1016/j.envpol.2024.123572] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/27/2023] [Revised: 01/29/2024] [Accepted: 02/13/2024] [Indexed: 02/20/2024]
Abstract
Plastic waste is a growing global pollutant. Plastic degradation by microorganisms has captured attention as an earth-friendly tactic. Although the mechanisms of plastic degradation by bacteria, fungi, and algae have been explored over the past decade, a large knowledge gap still exists regarding the identification, sorting, and cultivation of efficient plastic degraders, primarily because of their uncultivability. Advances in sequencing techniques and bioinformatics have enabled the identification of microbial degraders and related enzymes and genes involved in plastic biodegradation. In this review, we provide an outline of the situation of plastic degradation and summarize the methods for effective microbial identification using multidisciplinary techniques such as multiomics, meta-analysis, and spectroscopy. This review introduces new strategies for controlling plastic pollution in an environmentally friendly manner. Using this information, highly efficient and colonizing plastic degraders can be mined via targeted sorting and cultivation. In addition, based on the recognized rules and plastic degraders, we can perform an in-depth analysis of the associated degradation mechanism, metabolic features, and interactions.
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Affiliation(s)
- Ziyao Zhang
- College of Environment, Zhejiang University of Technology, Hangzhou, 310032, PR China
| | - Qi Zhang
- College of Environment, Zhejiang University of Technology, Hangzhou, 310032, PR China
| | - Huihui Yang
- College of Environment, Zhejiang University of Technology, Hangzhou, 310032, PR China
| | - Li Cui
- Key Laboratory of Urban Environment and Health, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen, 361021, PR China
| | - Haifeng Qian
- College of Environment, Zhejiang University of Technology, Hangzhou, 310032, PR China.
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6
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Zhang Z, Li Y, Zheng L, Jin M, Wu Y, Xu R, Luo Y, Wu J, Su W, Luo S, Huang Y, Wang C, Chang Z, Jiang D, Huang J. A novel method for high level production of protein glutaminase by sfGFP tag in Bacillus subtilis. Int J Biol Macromol 2024; 262:130092. [PMID: 38354920 DOI: 10.1016/j.ijbiomac.2024.130092] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2023] [Revised: 01/16/2024] [Accepted: 02/08/2024] [Indexed: 02/16/2024]
Abstract
Protein glutaminase (PG; EC 3.5.1.44) is a novel deamidase that helps to improve functional properties of food proteins. Currently, the highest activated PG enzyme activity was 26 U/mg when recombinantly expressed via the twin-arginine translocation (Tat) pathway in Corynebacterium glutamicum. In this study, superfolder green fluorescent protein (sfGFP) was used to replace traditional signal peptides to facilitate efficient heterologous expression and secretion of Propeptide-Protein glutaminase (PP) in Bacillus subtilis. The fusion protein, sfGFP-PP, was secreted from 12 h of fermentation and reached its highest extracellular expression at 28 h, with a secretion efficiency of about 93 %. Moreover, when fusing sfGFP with PP at the N-terminus, it significantly enhances PG expression up to 26 U/mL by approximately 2.2-fold compared to conventional signal-peptides- guided PP with 11.9 U/mL. Finally, the PG enzyme activity increased from 26 U/mL to 36.9 U/mL after promoter and RBS optimization. This strategy not only provides a new approach to increase PG production as well as extracellular secretion but also offers sfGFP as an effective N-terminal tag for increased secreted production of difficult-to-express proteins.
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Affiliation(s)
- Zheng Zhang
- School of Life Science, East China Normal University, Shanghai 200241, PR China
| | - Yuxi Li
- School of Life Science, East China Normal University, Shanghai 200241, PR China
| | - Lihui Zheng
- School of Life Science, East China Normal University, Shanghai 200241, PR China
| | - Mingfei Jin
- School of Life Science, East China Normal University, Shanghai 200241, PR China
| | - Yelin Wu
- Tongji University Cancer Center, Shanghai Tenth People's Hospital, Tongji University School of Medicine, Shanghai 200072, PR China
| | - Rui Xu
- School of Life Science, East China Normal University, Shanghai 200241, PR China
| | - Yin Luo
- School of Life Science, East China Normal University, Shanghai 200241, PR China
| | - Jiajing Wu
- School of Life Science, East China Normal University, Shanghai 200241, PR China
| | - Wei Su
- School of Life Science, East China Normal University, Shanghai 200241, PR China
| | - Shijing Luo
- School of Life Science, East China Normal University, Shanghai 200241, PR China
| | - Yuchen Huang
- School of Life Science, East China Normal University, Shanghai 200241, PR China
| | - Cong Wang
- School of Life Science, East China Normal University, Shanghai 200241, PR China
| | - Zhongyi Chang
- School of Life Science, East China Normal University, Shanghai 200241, PR China
| | - Deming Jiang
- School of Life Science, East China Normal University, Shanghai 200241, PR China.
| | - Jing Huang
- School of Life Science, East China Normal University, Shanghai 200241, PR China.
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7
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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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8
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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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9
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Qu Z, Chen K, Zhang L, Sun Y. Computation-Based Design of Salt Bridges in PETase for Enhanced Thermostability and Performance for PET Degradation. Chembiochem 2023; 24:e202300373. [PMID: 37639367 DOI: 10.1002/cbic.202300373] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2023] [Revised: 08/28/2023] [Accepted: 08/28/2023] [Indexed: 08/31/2023]
Abstract
Polyethylene terephthalate (PET) is one of the most widely used plastics, and the accumulation of PET poses a great threat to the environment. IsPETase can degrade PET rapidly at moderate temperatures, but its application is greatly limited by the low stability. Herein, molecular dynamics (MD) simulations combined with a sequence alignment strategy were adopted to introduce salt bridges into the flexible region of IsPETase to improve its thermal stability. In the designed variants, the Tm values of IsPETaseI168R/S188D and IsPETaseI168R/S188E were 7.4 and 8.7 °C higher than that of the wild type, respectively. The release of products degraded by IsPETaseI168R/S188E was 4.3 times that of the wild type. Tertiary structure characterization demonstrated that the structure of the variants IsPETaseI168R/S188D and IsPETaseI168R/S188E became more compact. Extensive MD simulations verified that a stable salt bridge was formed between the residue R168 and D186 in IsPETaseI168R/S188D , while in IsPETaseI168R/S188E an R168-D186-E188 salt bridge network was observed. These results confirmed that the proposed computation-based salt bridge design strategy could efficiently generate variants with enhanced thermal stability for the long-term degradation of PET, which would be helpful for the design of enzymes with improved stability.
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Affiliation(s)
- Zhi Qu
- Department of Biochemical Engineering, School of Chemical Engineering and Technology and, Key Laboratory of Systems Bioengineering and, Frontiers Science Center for Synthetic Biology (Ministry of Education), Tianjin University, Tianjin, 300350, China
| | - Kun Chen
- Department of Biochemical Engineering, School of Chemical Engineering and Technology and, Key Laboratory of Systems Bioengineering and, Frontiers Science Center for Synthetic Biology (Ministry of Education), Tianjin University, Tianjin, 300350, China
| | - Lin Zhang
- Department of Biochemical Engineering, School of Chemical Engineering and Technology and, 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 and, Key Laboratory of Systems Bioengineering and, Frontiers Science Center for Synthetic Biology (Ministry of Education), Tianjin University, Tianjin, 300350, China
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10
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Li X, Shi B, Huang JW, Zeng Z, Yang Y, Zhang L, Min J, Chen CC, Guo RT. Functional tailoring of a PET hydrolytic enzyme expressed in Pichia pastoris. BIORESOUR BIOPROCESS 2023; 10:26. [PMID: 38647782 PMCID: PMC10991172 DOI: 10.1186/s40643-023-00648-1] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2023] [Accepted: 03/27/2023] [Indexed: 04/25/2024] Open
Abstract
Using enzymes to hydrolyze and recycle poly(ethylene terephthalate) (PET) is an attractive eco-friendly approach to manage the ever-increasing PET wastes, while one major challenge to realize the commercial application of enzyme-based PET degradation is to establish large-scale production methods to produce PET hydrolytic enzyme. To achieve this goal, we exploited the industrial strain Pichia pastoris to express a PET hydrolytic enzyme from Caldimonas taiwanensis termed CtPL-DM. In contrast to the protein expressed in Escherichia coli, CtPL-DM expressed in P. pastoris is inactive in PET degradation. Structural analysis indicates that a putative N-glycosylation site N181 could restrain the conformational change of a substrate-binding Trp and hamper the enzyme action. We thus constructed N181A to remove the N-glycosylation and found that the PET hydrolytic activity of this variant was restored. The performance of N181A was further enhanced via molecular engineering. These results are of valuable in terms of PET hydrolytic enzyme production in industrial strains in the future.
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Affiliation(s)
- Xian Li
- State Key Laboratory of Biocatalysis and Enzyme Engineering, Hubei Hongshan Laboratory, Hubei Collaborative Innovation Center for Green Transformation of Bio-Resources, Hubei Key Laboratory of Industrial Biotechnology, School of Life Sciences, Hubei University, Wuhan, 430062, People's Republic of China
| | - Beilei Shi
- State Key Laboratory of Biocatalysis and Enzyme Engineering, Hubei Hongshan Laboratory, Hubei Collaborative Innovation Center for Green Transformation of Bio-Resources, Hubei Key Laboratory of Industrial Biotechnology, School of Life Sciences, Hubei University, Wuhan, 430062, People's Republic of China
| | - Jian-Wen Huang
- State Key Laboratory of Biocatalysis and Enzyme Engineering, Hubei Hongshan Laboratory, Hubei Collaborative Innovation Center for Green Transformation of Bio-Resources, Hubei Key Laboratory of Industrial Biotechnology, School of Life Sciences, Hubei University, Wuhan, 430062, People's Republic of China
| | - Ziyin Zeng
- State Key Laboratory of Biocatalysis and Enzyme Engineering, Hubei Hongshan Laboratory, Hubei Collaborative Innovation Center for Green Transformation of Bio-Resources, Hubei Key Laboratory of Industrial Biotechnology, School of Life Sciences, Hubei University, Wuhan, 430062, People's Republic of China
| | - Yu Yang
- State Key Laboratory of Biocatalysis and Enzyme Engineering, Hubei Hongshan Laboratory, Hubei Collaborative Innovation Center for Green Transformation of Bio-Resources, Hubei Key Laboratory of Industrial Biotechnology, School of Life Sciences, Hubei University, Wuhan, 430062, People's Republic of China
| | - Lilan Zhang
- State Key Laboratory of Biocatalysis and Enzyme Engineering, Hubei Hongshan Laboratory, Hubei Collaborative Innovation Center for Green Transformation of Bio-Resources, Hubei Key Laboratory of Industrial Biotechnology, School of Life Sciences, Hubei University, Wuhan, 430062, People's Republic of China
| | - Jian Min
- State Key Laboratory of Biocatalysis and Enzyme Engineering, Hubei Hongshan Laboratory, Hubei Collaborative Innovation Center for Green Transformation of Bio-Resources, Hubei Key Laboratory of Industrial Biotechnology, School of Life Sciences, Hubei University, Wuhan, 430062, People's Republic of China
| | - Chun-Chi Chen
- State Key Laboratory of Biocatalysis and Enzyme Engineering, Hubei Hongshan Laboratory, Hubei Collaborative Innovation Center for Green Transformation of Bio-Resources, Hubei Key Laboratory of Industrial Biotechnology, School of Life Sciences, Hubei University, Wuhan, 430062, People's Republic of China.
| | - Rey-Ting Guo
- State Key Laboratory of Biocatalysis and Enzyme Engineering, Hubei Hongshan Laboratory, Hubei Collaborative Innovation Center for Green Transformation of Bio-Resources, Hubei Key Laboratory of Industrial Biotechnology, School of Life Sciences, Hubei University, Wuhan, 430062, People's Republic of China.
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11
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Zurier HS, Goddard JM. A high-throughput expression and screening platform for applications-driven PETase engineering. Biotechnol Bioeng 2023; 120:1000-1014. [PMID: 36575047 DOI: 10.1002/bit.28319] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2022] [Revised: 12/20/2022] [Accepted: 12/26/2022] [Indexed: 12/29/2022]
Abstract
The environmental consequences of plastic waste have impacted all kingdoms of life in terrestrial and aquatic ecosystems. However, as the burden of plastic pollution has increased, microbes have evolved to utilize anthropogenic polymers as nutrient sources. Of depolymerase enzymes, the best characterized is PETase, which hydrolyzes aromatic polyesters. PETase engineering has made impressive progress in recent years; however, further optimization of engineered PETase toward industrial application has been limited by lower throughput techniques used in protein purification and activity detection. Here, we address these deficiencies through development of a higher-throughput PETase engineering platform. Secretory expression via YebF tagging eliminates lysis and purification steps, facilitating production of large mutant libraries. Fluorescent detection of degradation products permits rapid screening of depolymerase activity in microplates as opposed to serial chromatographic methods. This approach enabled development of more stable PETase, semi-rational (SR) PETase variant containing previously unpublished mutations. SR-PETase releases 1.9-fold more degradation products and has up to 7.4-fold higher activity than wild-type PETase over 10 days at 40°C. These methods can be adapted to a variety of chemical environments, enabling screening of PETase mutants in applications-relevant conditions. Overall, this work promises to facilitate advancements in PETase engineering toward industrial depolymerization of plastic waste.
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Affiliation(s)
- Hannah S Zurier
- Department of Food Science and Technology, Cornell University, Ithaca, New York, USA
| | - Julie M Goddard
- Department of Food Science and Technology, Cornell University, Ithaca, New York, USA
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12
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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: 24] [Impact Index Per Article: 24.0] [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.
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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
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13
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Schaerer LG, Wu R, Putman LI, Pearce JM, Lu T, Shonnard DR, Ong RG, Techtmann SM. Killing two birds with one stone: chemical and biological upcycling of polyethylene terephthalate plastics into food. Trends Biotechnol 2023; 41:184-196. [PMID: 36058768 DOI: 10.1016/j.tibtech.2022.06.012] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2022] [Revised: 05/24/2022] [Accepted: 06/21/2022] [Indexed: 01/24/2023]
Abstract
Most polyethylene terephthalate (PET) plastic waste is landfilled or pollutes the environment. Additionally, global food production must increase to support the growing population. This article explores the feasibility of using microorganisms in an industrial system that upcycles PET into edible microbial protein powder to solve both problems simultaneously. Many microorganisms can utilize plastics as feedstock, and the resultant microbial biomass contains fats, nutrients, and proteins similar to those found in human diets. While microbial degradation of PET is promising, biological PET depolymerization is too slow to resolve the global plastic crisis and projected food shortages. Evidence reviewed here suggests that by coupling chemical depolymerization and biological degradation of PET, and using cooperative microbial communities, microbes can efficiently convert PET waste into food.
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Affiliation(s)
- Laura G Schaerer
- Department of Biological Sciences, Michigan Technological University, Houghton, MI, USA
| | - Ruochen Wu
- Department of Chemical Engineering, Michigan Technological University, Houghton, MI, USA
| | - Lindsay I Putman
- Department of Biological Sciences, Michigan Technological University, Houghton, MI, USA
| | - Joshua M Pearce
- Department of Electrical and Computer Engineering, Western University, London, Ontario, Canada
| | - Ting Lu
- Department of Bioengineering, University of Illinois Urbana-Champaign, Champaign, IL, USA
| | - David R Shonnard
- Department of Chemical Engineering, Michigan Technological University, Houghton, MI, USA
| | - Rebecca G Ong
- Department of Chemical Engineering, Michigan Technological University, Houghton, MI, USA
| | - Stephen M Techtmann
- Department of Biological Sciences, Michigan Technological University, Houghton, MI, USA.
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14
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Mudondo J, Lee HS, Jeong Y, Kim TH, Kim S, Sung BH, Park SH, Park K, Cha HG, Yeon YJ, Kim HT. Recent Advances in the Chemobiological Upcycling of Polyethylene Terephthalate (PET) into Value-Added Chemicals. J Microbiol Biotechnol 2023; 33:1-14. [PMID: 36451300 PMCID: PMC9895998 DOI: 10.4014/jmb.2208.08048] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2022] [Revised: 10/02/2022] [Accepted: 10/04/2022] [Indexed: 12/02/2022]
Abstract
Polyethylene terephthalate (PET) is a plastic material commonly applied to beverage packaging used in everyday life. Owing to PET's versatility and ease of use, its consumption has continuously increased, resulting in considerable waste generation. Several physical and chemical recycling processes have been developed to address this problem. Recently, biological upcycling is being actively studied and has come to be regarded as a powerful technology for overcoming the economic issues associated with conventional recycling methods. For upcycling, PET should be degraded into small molecules, such as terephthalic acid and ethylene glycol, which are utilized as substrates for bioconversion, through various degradation processes, including gasification, pyrolysis, and chemical/biological depolymerization. Furthermore, biological upcycling methods have been applied to biosynthesize value-added chemicals, such as adipic acid, muconic acid, catechol, vanillin, and glycolic acid. In this review, we introduce and discuss various degradation methods that yield substrates for bioconversion and biological upcycling processes to produce value-added biochemicals. These technologies encourage a circular economy, which reduces the amount of waste released into the environment.
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Affiliation(s)
- Joyce Mudondo
- Department of Food Science and Technology, Chungnam National University, Daejeon 34134, Republic of Korea
| | - Hoe-Suk Lee
- Department of Biochemical Engineering Gangneung-Wonju National University, Gangneung 25457, Republic of Korea
| | - Yunhee Jeong
- Department of Food Science and Technology, Chungnam National University, Daejeon 34134, Republic of Korea
| | - Tae Hee Kim
- Department of Food Science and Technology, Chungnam National University, Daejeon 34134, Republic of Korea
| | - Seungmi Kim
- Department of Food Science and Technology, Chungnam National University, Daejeon 34134, Republic of Korea
| | - Bong Hyun Sung
- Synthetic Biology Research Center, Korea Research Institute of Bioscience and Biotechnology, Daejeon 34141, Republic of Korea
| | - See-Hyoung Park
- Department of Biological and Chemical Engineering, Hongik University, Sejong 30016, Republic of Korea
| | - Kyungmoon Park
- Department of Biological and Chemical Engineering, Hongik University, Sejong 30016, Republic of Korea
| | - Hyun Gil Cha
- Center for Bio-based Chemistry, Korea Research Institute of Chemical Technology (KRICT), Ulsan 44429, Republic of Korea,Corresponding authors H.G. Cha Phone: +82-52-241-6317 Fax: +82-52-241-6349 E-mail:
| | - Young Joo Yeon
- Department of Biochemical Engineering Gangneung-Wonju National University, Gangneung 25457, Republic of Korea,Y.J. Yeon Phone: +82-33-640-2401 Fax: +82-33-640-2410 E-mail:
| | - Hee Taek Kim
- Department of Food Science and Technology, Chungnam National University, Daejeon 34134, Republic of Korea,H.T. Kim Phone: +82-42-821-6722 Fax:+82-42-821-8785 E-mail:
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15
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Improving the activity and thermostability of PETase from Ideonella sakaiensis through modulating its post-translational glycan modification. Commun Biol 2023; 6:39. [PMID: 36639437 PMCID: PMC9839772 DOI: 10.1038/s42003-023-04413-0] [Citation(s) in RCA: 9] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2022] [Accepted: 01/03/2023] [Indexed: 01/14/2023] Open
Abstract
The large-scale preparation of Polyehylene terephthalate (PET) hydrolysing enzymes in low-cost is critical for the biodegradation of PET in industry. In the present study, we demonstrate that the post-translational glycosylation of Pichia pastoris makes it a remarkable host for the heterologous expression of PETase from Ideonella sakaiensis 201-F6 (IsPETase). Taking advantage of the abundant N- and O-linked glycosylation sites in IsPETase and the efficient post-translational modification in endoplasmic reticulum, IsPETase is heavily glycosylated during secretory expression with P. pastoris, which improves the specific activity and thermostability of the enzyme dramatically. Moreover, the specific activity of IsPETase increased further after the bulky N-linked polysaccharide chains were eliminated by Endo-β-N-acetylglucosaminidase H (Endo H). Importantly, the partially deglycosylated IsPETase still maintained high thermostability because of the remaining mono- and oligo-saccharide residues on the protein molecules. Consequently, the partially deglycosylated IsPETase was able to be applied at 50 °C and depolymerized raw, untreated PET flakes completely in 2 to 3 days. This platform was also applied for the preparation of a famous variant of IsPETase, Fast-PETase, and the same result was achieved. Partially deglycosylated Fast-PETase demonstrates elevated efficiency in degrading postconsumer-PET trays under 55 °C than 50 °C, the reported optimal temperature of Fast-PETase. The present study provides a strategy to modulate thermostable IsPETase through glycosylation engineering and paves the way for promoting PET biodegradation from laboratories to factories.
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16
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Jiang Z, Xie X, Li Z, Ban X, Gu Z, Tang X, Hong Y, Cheng L, Li C. Regulation of Cell Membrane Permeability Enhanced the Non-Classical Secretion of γ-Cyclodextrin Glycosyltransferase in Bacillus subtilis. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2022; 70:16307-16315. [PMID: 36524966 DOI: 10.1021/acs.jafc.2c08320] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/17/2023]
Abstract
γ-Cyclodextrin glycosyltransferase (γ-CGTase, EC 2.4.1.19) is an essential enzyme required in the production of γ-cyclodextrin, which shows huge prospects in the food, medicine, materials, and chemical industries. In this study, γ-CGTase from Bacillus sp. G-825-6 STB17 was successfully cloned and expressed in Bacillus subtilis WB600. The final extracellular activity of γ-CGTase can reach 45.34 U/mL with the deletion of the signal peptide, which was about 11.3 times of the initial level of γ-CGTase secreted by the general pathway. By monitoring the whole cultivation process, secretion was divided into two stages, which were dominated by cell membrane changes and apoptosis. The measurement of lactate dehydrogenase and the results of fluorescence microscopy demonstrated that the cell membrane permeability changed significantly in the middle stage of fermentation, proving that it played a crucial role in the non-classical secretion of γ-CGTase. Furthermore, the addition of Triton X-100, a non-ionic surfactant, remarkably enhanced the secretion level of γ-CGTase by 21.5%, which was caused by the increase in cell membrane permeability. This work is the first to obtain the extracellular expression of CGTase via the non-classical secretion pathway in B. subtilis and provides a new strategy to enhance extracellular expression by regulating the cell membranes.
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Affiliation(s)
- Zihang Jiang
- School of Food Science and Technology, Jiangnan University, Wuxi, Jiangsu 214122, People's Republic of China
| | - Xiaofang Xie
- Department of Food Science and Technology, National University of Singapore, Singapore 117542, Singapore
| | - Zhaofeng Li
- Key Laboratory of Synergetic and Biological Colloids, Ministry of Education, Wuxi, Jiangsu 214122, People's Republic of China
- School of Food Science and Technology, Jiangnan University, Wuxi, Jiangsu 214122, People's Republic of China
- Collaborative Innovation Center of Food Safety and Quality Control, Jiangnan University, Wuxi, Jiangsu 214122, People's Republic of China
| | - Xiaofeng Ban
- Key Laboratory of Synergetic and Biological Colloids, Ministry of Education, Wuxi, Jiangsu 214122, People's Republic of China
- School of Food Science and Technology, Jiangnan University, Wuxi, Jiangsu 214122, People's Republic of China
| | - Zhengbiao Gu
- Key Laboratory of Synergetic and Biological Colloids, Ministry of Education, Wuxi, Jiangsu 214122, People's Republic of China
- School of Food Science and Technology, Jiangnan University, Wuxi, Jiangsu 214122, People's Republic of China
- Collaborative Innovation Center of Food Safety and Quality Control, Jiangnan University, Wuxi, Jiangsu 214122, People's Republic of China
| | - Xiaoshu Tang
- School of Food Science and Technology, Jiangnan University, Wuxi, Jiangsu 214122, People's Republic of China
- National Engineering Research Center for Functional Food, Jiangnan University, Wuxi, Jiangsu 214122, People's Republic of China
| | - Yan Hong
- Key Laboratory of Synergetic and Biological Colloids, Ministry of Education, Wuxi, Jiangsu 214122, People's Republic of China
- School of Food Science and Technology, Jiangnan University, Wuxi, Jiangsu 214122, People's Republic of China
- Collaborative Innovation Center of Food Safety and Quality Control, Jiangnan University, Wuxi, Jiangsu 214122, People's Republic of China
| | - Li Cheng
- Key Laboratory of Synergetic and Biological Colloids, Ministry of Education, Wuxi, Jiangsu 214122, People's Republic of China
- School of Food Science and Technology, Jiangnan University, Wuxi, Jiangsu 214122, People's Republic of China
- Collaborative Innovation Center of Food Safety and Quality Control, Jiangnan University, Wuxi, Jiangsu 214122, People's Republic of China
| | - Caiming Li
- Key Laboratory of Synergetic and Biological Colloids, Ministry of Education, Wuxi, Jiangsu 214122, People's Republic of China
- School of Food Science and Technology, Jiangnan University, Wuxi, Jiangsu 214122, People's Republic of China
- Collaborative Innovation Center of Food Safety and Quality Control, Jiangnan University, Wuxi, Jiangsu 214122, People's Republic of China
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Abomohra A, Hanelt D. Recent Advances in Micro-/Nanoplastic (MNPs) Removal by Microalgae and Possible Integrated Routes of Energy Recovery. Microorganisms 2022; 10:microorganisms10122400. [PMID: 36557653 PMCID: PMC9788109 DOI: 10.3390/microorganisms10122400] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2022] [Revised: 11/29/2022] [Accepted: 11/30/2022] [Indexed: 12/12/2022] Open
Abstract
Reliance on plastic has resulted in the widespread occurrence of micro-/nanoplastics (MNPs) in aquatic ecosystems, threatening the food web and whole ecosystem functions. There is a tight interaction between MNPs and microalgae, as dominant living organisms and fundamental constituents at the base of the aquatic food web. Therefore, it is crucial to better understand the mechanisms underlying the interactions between plastic particles and microalgae, as well as the role of microalgae in removing MNPs from aquatic ecosystems. In addition, finding a suitable route for further utilization of MNP-contaminated algal biomass is of great importance. The present review article provides an interdisciplinary approach to elucidate microalgae-MNP interactions and subsequent impacts on microalgal physiology. The degradation of plastic in the environment and differences between micro- and nanoplastics are discussed. The possible toxic effects of MNPs on microalgal growth, photosynthetic activity, and morphology, due to physical or chemical interactions, are evaluated. In addition, the potential role of MNPs in microalgae cultivation and/or harvesting, together with further safe routes for biomass utilization in biofuel production, are suggested. Overall, the current article represents a state-of-the-art overview of MNP generation and the consequences of their accumulation in the environment, providing new insights into microalgae integrated routes of plastic removal and bioenergy production.
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18
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Zurier HS, Goddard JM. Directed Immobilization of PETase on Mesoporous Silica Enables Sustained Depolymerase Activity in Synthetic Wastewater Conditions. ACS APPLIED BIO MATERIALS 2022; 5:4981-4992. [PMID: 36194455 DOI: 10.1021/acsabm.2c00700] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Microplastic accumulation in terrestrial and aquatic environments is a growing environmental challenge. Biodegradation has shown promise as an intervention strategy for reducing the spread of microplastics. The wastewater treatment system is a key intervention point in microplastic biodegradation due to its pivotal role in the water cycle at the interface between human activity and the environmental. However, the best characterized microplastic degradation enzyme, PETase, lacks the stability to perform at scale in wastewater treatment. In this work, we show that genetic fusion of PETase to a silica binding peptide enables directed immobilization of the enzyme onto silica nanoparticles. PETase activity in simulated wastewater conditions is quantified by linear regression from time zero to the time of maximum fluorescence of a fluorescent oxidized product of PETase degradation of PET microfibers. Mesoporous silica is shown to be a superior support material to nonporous silica. The resulting biocatalytic nanomaterial has up to 2.5-fold enhanced stability and 6.2-fold increased activity compared to free enzyme in unbuffered, 40 °C simulated influent (ionic strength ∼15 mM). In unbuffered, 40 °C simulated effluent (ionic strength ∼700 μM), reaction velocity and overall catalytic activity were increased by the biocatalytic material 2.1-fold relative to free PETase. All reactions were performed in 0.2 mL volumes, and enzyme concentrations were normalized across both free and immobilized samples to 9 μg/mL. Site-directed mutagenesis is shown to be a complementary technique to directed immobilization, which may aid in optimization of the biomaterial for wastewater applications. PETase stabilization in application-relevant environments as shown here enables progress toward application of PETase for microplastic biodegradation in wastewater treatment.
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Affiliation(s)
- Hannah S Zurier
- Department of Food Science and Technology, Cornell University, Ithaca, New York14853, United States
| | - Julie M Goddard
- Department of Food Science and Technology, Cornell University, Ithaca, New York14853, United States
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19
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Microbial degradation of polyethylene terephthalate: a systematic review. SN APPLIED SCIENCES 2022. [DOI: 10.1007/s42452-022-05143-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022] Open
Abstract
AbstractPlastic pollution levels have increased rapidly in recent years, due to the accumulation of plastic waste, including polyethylene terephthalate (PET). Both high production and the lack of efficient methods for disposal and recycling affect diverse aquatic and terrestrial ecosystems owing to the high accumulation rates of plastics. Traditional chemical and physical degradation techniques have caused adverse effects on the environment; hence, the use of microorganisms for plastic degradation has gained importance recently. This systematic review was conducted for evaluating the reported findings about PET degradation by wild and genetically modified microorganisms to make them available for future work and to contribute to the eventual implementation of an alternative, an effective, and environmentally friendly method for the management of plastic waste such as PET. Both wild and genetically modified microorganisms with the metabolic potential to degrade this polymer were identified, in addition to the enzymes and genes used for genetic modification. The most prevalent wild-type PET-degrading microorganisms were bacteria (56.3%, 36 genera), followed by fungi (32.4%, 30 genera), microalgae (1.4%; 1 genus, namely Spirulina sp.), and invertebrate associated microbiota (2.8%). Among fungi and bacteria, the most prevalent genera were Aspergillus sp. and Bacillus sp., respectively. About genetically modified microorganisms, 50 strains of Escherichia coli, most of them expressing PETase enzyme, have been used. We emphasize the pressing need for implementing biological techniques for PET waste management on a commercial scale, using consortia of microorganisms. We present this work in five sections: an Introduction that highlights the importance of PET biodegradation as an effective and sustainable alternative, a section on Materials and methods that summarizes how the search for articles and manuscripts in different databases was done, and another Results section where we present the works found on the subject, a final part of Discussion and analysis of the literature found and finally we present a Conclusion and prospects.
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20
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Haque F, Fan C. Prospect of microplastic pollution control under the "New normal" concept beyond COVID-19 pandemic. JOURNAL OF CLEANER PRODUCTION 2022; 367:133027. [PMID: 35821718 PMCID: PMC9257196 DOI: 10.1016/j.jclepro.2022.133027] [Citation(s) in RCA: 19] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/25/2022] [Revised: 05/19/2022] [Accepted: 07/02/2022] [Indexed: 05/04/2023]
Abstract
Coronavirus disease (COVID-19) has led to increasing demand for single-use plastic which aggravates the already existing plastic waste problem. Not only does the demand for personal protective equipment (PPE) increase, but also people shift their preference to online shopping and food delivery to comply with administrative policies for COVID-19 pandemic control. The used PPEs, packaging materials, and food containers may not be handled or recycled properly after their disposal. As a result, the mismanaged plastic waste is discharged into the environment and it may pose even greater risks after breaking into smaller fragments, which was regarded as the source of secondary microplastics (MPs, < 5 mm) or nanoplastics (NPs, < 1 μm). The main objective of this manuscript is to provide a review of the studies related to microplastic release due to pandemic-associated plastic waste. This study summarizes the limited work published on the ecotoxicological/toxicological effect of MPs/NPs released from PPE on aquatic organisms, soil organisms, as well as humans. Given the current status of research on MPs from COVID-related plastic waste, the immediate research directions needed on this topic were discussed.
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Affiliation(s)
- Fatima Haque
- Department of Bioenvironmental Systems Engineering, National Taiwan University, No. 1, Sec. 4, Roosevelt Rd, Da-An District, Taipei, Taiwan, 10617
| | - Chihhao Fan
- Department of Bioenvironmental Systems Engineering, National Taiwan University, No. 1, Sec. 4, Roosevelt Rd, Da-An District, Taipei, Taiwan, 10617
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21
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Aer L, Jiang Q, Gul I, Qi Z, Feng J, Tang L. Overexpression and kinetic analysis of Ideonella sakaiensis PETase for polyethylene terephthalate (PET) degradation. ENVIRONMENTAL RESEARCH 2022; 212:113472. [PMID: 35577005 DOI: 10.1016/j.envres.2022.113472] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/31/2022] [Revised: 05/08/2022] [Accepted: 05/10/2022] [Indexed: 06/15/2023]
Abstract
Ideonella sakaiensis PET hydrolase (IsPETase) is a well-characterized enzyme for effective PET biodegradation. However, the low soluble expression level of the enzyme hampers its practical implementation in the biodegradation of PET. Herein, the expression of IsPETaseMut, one of the most active mutants of IsPETase obtained so far, was systematically explored in E. coli by adopting a series of strategies. A notable improvement of soluble IsPETaseMut was observed by using chaperon co-expression and fusion expression systems. Under the optimized conditions, GroEL/ES co-expression system yielded 75 ± 3.4 mg·L-1 purified soluble IsPETaseMut (GroEL/ES), and NusA fusion expression system yielded 80 ± 3.7 mg·L-1 purified soluble NusA-IsPETaseMut, which are 12.5- and 4.6-fold, respectively, higher than its commonly expression in E. coli. The two purified enzymes were further characterized. The results showed that IsPETaseMut (GroEL/ES) displayed the same catalytic behavior as IsPETaseMut, while the fusion of NusA conferred new enzymatic properties to IsPETaseMut. Although NusA-IsPETaseMut displayed a lower initial hydrolysis capacity than IsPETaseMut, it showed a 1.4-fold higher adsorption constant toward PET. Moreover, the product inhibition effect of terephthalic acid (TPA) on IsPETase was reduced with NusA-IsPETaseMut. Taken together, the latter two catalytic properties of NusA-IsPETaseMut are more likely to contribute to the enhanced product release by NusA-IsPETaseMut PET degradation for two weeks.
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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
| | - Ijaz Gul
- School of Life Science and Technology, University of Electronic Science and Technology of China, Chengdu, 610054, China; Institute of Biopharmaceutical and Health Engineering, Tsinghua Shenzhen International Graduate School, Tsinghua University, Shenzhen, 518055, PR China
| | - Zixuan Qi
- School of Life Science and Technology, 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
| | - 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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22
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Abstract
Human activity and modern production contribute to the formation of a certain amount of waste that can be recycled to obtain useful products and energy sources. Today, the higher the level of industrial development, the greater the amount of waste generated, and as a result, the more important the need for disposal. A similar pattern is typical for any human production activity; as a result of large-scale production, at least 70–80% of waste is generated in relation to the amount of raw materials used. The large-scale use of polymeric materials and the plastic waste generated after their use lead to environmental pollution. While a small part of the waste is utilized naturally due to the vital activity of soil microorganisms, and a part is purposefully processed by humans into products for various purposes, a fairly large amount of waste occupies large areas in the form of a variety of garbage. After the removal of garbage by incineration, the liberated territories cannot be transferred to agricultural land due to the high content of harmful contaminants. The harm to the environment is quite obvious. In practice, certain types of waste consist of more than 70% content of valuable substances that can find further practical application in a wide variety of industries.
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Brandenberg OF, Schubert OT, Kruglyak L. Towards synthetic PETtrophy: Engineering Pseudomonas putida for concurrent polyethylene terephthalate (PET) monomer metabolism and PET hydrolase expression. Microb Cell Fact 2022; 21:119. [PMID: 35717313 PMCID: PMC9206389 DOI: 10.1186/s12934-022-01849-7] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2022] [Accepted: 05/26/2022] [Indexed: 12/27/2022] Open
Abstract
BACKGROUND Biocatalysis offers a promising path for plastic waste management and valorization, especially for hydrolysable plastics such as polyethylene terephthalate (PET). Microbial whole-cell biocatalysts for simultaneous PET degradation and growth on PET monomers would offer a one-step solution toward PET recycling or upcycling. We set out to engineer the industry-proven bacterium Pseudomonas putida for (i) metabolism of PET monomers as sole carbon sources, and (ii) efficient extracellular expression of PET hydrolases. We pursued this approach for both PET and the related polyester polybutylene adipate co-terephthalate (PBAT), aiming to learn about the determinants and potential applications of bacterial polyester-degrading biocatalysts. RESULTS P. putida was engineered to metabolize the PET and PBAT monomer terephthalic acid (TA) through genomic integration of four tphII operon genes from Comamonas sp. E6. Efficient cellular TA uptake was enabled by a point mutation in the native P. putida membrane transporter MhpT. Metabolism of the PET and PBAT monomers ethylene glycol and 1,4-butanediol was achieved through adaptive laboratory evolution. We then used fast design-build-test-learn cycles to engineer extracellular PET hydrolase expression, including tests of (i) the three PET hydrolases LCC, HiC, and IsPETase; (ii) genomic versus plasmid-based expression, using expression plasmids with high, medium, and low cellular copy number; (iii) three different promoter systems; (iv) three membrane anchor proteins for PET hydrolase cell surface display; and (v) a 30-mer signal peptide library for PET hydrolase secretion. PET hydrolase surface display and secretion was successfully engineered but often resulted in host cell fitness costs, which could be mitigated by promoter choice and altering construct copy number. Plastic biodegradation assays with the best PET hydrolase expression constructs genomically integrated into our monomer-metabolizing P. putida strains resulted in various degrees of plastic depolymerization, although self-sustaining bacterial growth remained elusive. CONCLUSION Our results show that balancing extracellular PET hydrolase expression with cellular fitness under nutrient-limiting conditions is a challenge. The precise knowledge of such bottlenecks, together with the vast array of PET hydrolase expression tools generated and tested here, may serve as a baseline for future efforts to engineer P. putida or other bacterial hosts towards becoming efficient whole-cell polyester-degrading biocatalysts.
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Affiliation(s)
- Oliver F Brandenberg
- Department of Human Genetics, Department of Biological Chemistry, and Howard Hughes Medical Institute, University of California Los Angeles, Los Angeles, USA.
| | - Olga T Schubert
- Department of Human Genetics, Department of Biological Chemistry, and Howard Hughes Medical Institute, University of California Los Angeles, Los Angeles, USA.,Department of Environmental Microbiology, EAWAG, 8600, Dübendorf, Switzerland.,Department of Environmental Systems Science, ETH Zurich, 8092, Zürich, Switzerland
| | - Leonid Kruglyak
- Department of Human Genetics, Department of Biological Chemistry, and Howard Hughes Medical Institute, University of California Los Angeles, Los Angeles, USA.
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Shen JD, Cai X, Liu ZQ, Zheng YG. High Throughput Screening of Signal Peptide Library with Novel Fluorescent Probe. Chembiochem 2022; 23:e202100523. [PMID: 35470527 DOI: 10.1002/cbic.202100523] [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: 09/30/2021] [Revised: 04/14/2022] [Indexed: 11/06/2022]
Abstract
Nitrile hydratase (NHase) is an excellent bio-catalyst for the synthesis of amide compounds, was composed of two heterologous subunits. However, the secretory expression of NHase has been difficult to achieve because of its complex expression mechanism. In this work, a novel fluorescent probe Rho-IDA-CoII was synthesized by the one-pot method. Rho-IDA-CoII could specifically label His-tagged proteins in vitro specifically, such as staining in-gel, western blot and ELISA. Furthermore, Rho-IDA-CoII combined with dot blot could quantitatively detect His-tagged proteins between 1 - 10 pmol and perform high-throughput screening for the NHase signal peptide library. The recombinant Bacillus subtilis WB800/phoB-HBA with the extracellular expression of NHase was screened from ca. 6500 clones. After optimization of fermentation conditions, the NHase activity in the culture supernatant reached to 17.34 ± 0.16 U/mL. It was the first time to express secretory NHase in Bacillus subtilis successfully.
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Affiliation(s)
- Ji-Dong Shen
- Zhejiang University of Technology, College of biotechnology and bioengineering, CHINA
| | - Xue Cai
- Zhejiang University of Technology, college of biotechnology and bioengineering, CHINA
| | - Zhi-Qiang Liu
- Zhejiang University of Technology, College of Biotechnology and Bioengineering, Chaowang Rd. 18#, 3100114, Hangzhou, CHINA
| | - Yu-Guo Zheng
- Zhejiang University of Technology, college of biotechnology and bioengineering, CHINA
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25
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Koryagina AO, Osmanova FR, Toymentseva AA, Laikov AV, Sharipova MR. Quantitative Analysis of Bacillus pumilus Serine Proteinases in Recombinant Bacillus Strains. Microbiology (Reading) 2022. [DOI: 10.1134/s0026261722020060] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
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26
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Tiwari N, Bansal M, Santhiya D, Sharma JG. Insights into microbial diversity on plastisphere by multi-omics. Arch Microbiol 2022; 204:216. [PMID: 35316402 DOI: 10.1007/s00203-022-02806-z] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2021] [Revised: 02/13/2022] [Accepted: 02/14/2022] [Indexed: 12/20/2022]
Abstract
Plastic pollution is a major concern in marine environment as it takes many years to degrade and is one of the greatest threats to marine life. Plastic surface, referred to as plastisphere, provides habitat for growth and proliferation of various microorganisms. The discovery of these microbes is necessary to identify significant genes, enzymes and bioactive compounds that could help in bioremediation and other commercial applications. Conventional culture techniques have been successful in identifying few microbes from these habitats, leaving majority of them yet to be explored. As such, to recognize the vivid genetic diversity of microbes residing in plastisphere, their structure and corresponding ecological roles within the ecosystem, an emerging technique, called metagenomics has been explored. The technique is expected to provide hitherto unknown information on microbes from the plastisphere. Metagenomics along with next generation sequencing provides comprehensive knowledge on microbes residing in plastisphere that identifies novel microbes for plastic bioremediation, bioactive compounds and other potential benefits. The following review summarizes the efficiency of metagenomics and next generation sequencing technology over conventionally used methods for culturing microbes. It attempts to illustrate the workflow mechanism of metagenomics to elucidate diverse microbial profiles. Further, importance of integrated multi-omics techniques has been highlighted in discovering microbial ecology residing on plastisphere for wider applications.
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Affiliation(s)
- Neha Tiwari
- Department of Biotechnology, Delhi Technological University, Delhi, India
| | - Megha Bansal
- Department of Biotechnology, Delhi Technological University, Delhi, India
| | - Deenan Santhiya
- Department of Applied Chemistry, Delhi Technological University, Shahbad Daulatpur, Main Bawana Road, Delhi, 110042, India.
| | - Jai Gopal Sharma
- Department of Biotechnology, Delhi Technological University, Delhi, India
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Dhaka V, Singh S, Anil AG, Sunil Kumar Naik TS, Garg S, Samuel J, Kumar M, Ramamurthy PC, Singh J. Occurrence, toxicity and remediation of polyethylene terephthalate plastics. A review. ENVIRONMENTAL CHEMISTRY LETTERS 2022; 20:1777-1800. [PMID: 35039752 PMCID: PMC8755403 DOI: 10.1007/s10311-021-01384-8] [Citation(s) in RCA: 48] [Impact Index Per Article: 24.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/16/2021] [Accepted: 12/29/2021] [Indexed: 05/31/2023]
Abstract
Polyethylene terephthalate is a common plastic in many products such as viscose rayon for clothing, and packaging material in the food and beverage industries. Polyethylene terephthalate has beneficial properties such as light weight, high tensile strength, transparency and gas barrier. Nonetheless, there is actually increasing concern about plastic pollution and toxicity. Here we review the properties, occurrence, toxicity, remediation and analysis of polyethylene terephthalate as macroplastic, mesoplastic, microplastic and nanoplastic. Polyethylene terephthalate occurs in groundwater, drinking water, soils and sediments. Plastic uptake by humans induces diseases such as reducing migration and proliferation of human mesenchymal stem cells of bone marrow and endothelial progenitor cells. Polyethylene terephthalate can be degraded by physical, chemical and biological methods.
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Affiliation(s)
- Vaishali Dhaka
- Department of Microbiology, Lovely Professional University, Phagwara, Punjab 144411 India
| | - Simranjeet Singh
- Interdisciplinary Centre for Water Research (ICWaR), Indian Institute of Science, Bangalore, 560012 India
| | - Amith G. Anil
- Department of Material Engineering, Indian Institute of Science, Bangalore, 560012 India
| | - T. S. Sunil Kumar Naik
- Interdisciplinary Centre for Water Research (ICWaR), Indian Institute of Science, Bangalore, 560012 India
| | - Shashank Garg
- Department of Microbiology, Lovely Professional University, Phagwara, Punjab 144411 India
| | - Jastin Samuel
- Waste Valorization Research Lab, Lovely Professional University, Phagwara, Punjab 144411 India
| | - Manoj Kumar
- Department of Life Sciences, Central University Jharkhand, Brambe, Ranchi, Jharkhand 835205 India
| | - Praveen C. Ramamurthy
- Interdisciplinary Centre for Water Research (ICWaR), Indian Institute of Science, Bangalore, 560012 India
| | - Joginder Singh
- Department of Microbiology, Lovely Professional University, Phagwara, Punjab 144411 India
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Qi X, Yan W, Cao Z, Ding M, Yuan Y. Current Advances in the Biodegradation and Bioconversion of Polyethylene Terephthalate. Microorganisms 2021; 10:39. [PMID: 35056486 PMCID: PMC8779501 DOI: 10.3390/microorganisms10010039] [Citation(s) in RCA: 21] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2021] [Revised: 12/15/2021] [Accepted: 12/20/2021] [Indexed: 01/04/2023] Open
Abstract
Polyethylene terephthalate (PET) is a widely used plastic that is polymerized by terephthalic acid (TPA) and ethylene glycol (EG). In recent years, PET biodegradation and bioconversion have become important in solving environmental plastic pollution. More and more PET hydrolases have been discovered and modified, which mainly act on and degrade the ester bond of PET. The monomers, TPA and EG, can be further utilized by microorganisms, entering the tricarboxylic acid cycle (TCA cycle) or being converted into high value chemicals, and finally realizing the biodegradation and bioconversion of PET. Based on synthetic biology and metabolic engineering strategies, this review summarizes the current advances in the modified PET hydrolases, engineered microbial chassis in degrading PET, bioconversion pathways of PET monomers, and artificial microbial consortia in PET biodegradation and bioconversion. Artificial microbial consortium provides novel ideas for the biodegradation and bioconversion of PET or other complex polymers. It is helpful to realize the one-step bioconversion of PET into high value chemicals.
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Affiliation(s)
- Xinhua Qi
- Frontier Science Center for Synthetic Biology and Key Laboratory of Systems Bioengineering (Ministry of Education), School of Chemical Engineering and Technology, Tianjin University, Tianjin 300072, China; (X.Q.); (W.Y.); (Z.C.); (Y.Y.)
- Collaborative Innovation Center of Chemical Science and Engineering (Tianjin), Tianjin University, Tianjin 300072, China
| | - Wenlong Yan
- Frontier Science Center for Synthetic Biology and Key Laboratory of Systems Bioengineering (Ministry of Education), School of Chemical Engineering and Technology, Tianjin University, Tianjin 300072, China; (X.Q.); (W.Y.); (Z.C.); (Y.Y.)
- Collaborative Innovation Center of Chemical Science and Engineering (Tianjin), Tianjin University, Tianjin 300072, China
| | - Zhibei Cao
- Frontier Science Center for Synthetic Biology and Key Laboratory of Systems Bioengineering (Ministry of Education), School of Chemical Engineering and Technology, Tianjin University, Tianjin 300072, China; (X.Q.); (W.Y.); (Z.C.); (Y.Y.)
- Collaborative Innovation Center of Chemical Science and Engineering (Tianjin), Tianjin University, Tianjin 300072, China
| | - Mingzhu Ding
- Frontier Science Center for Synthetic Biology and Key Laboratory of Systems Bioengineering (Ministry of Education), School of Chemical Engineering and Technology, Tianjin University, Tianjin 300072, China; (X.Q.); (W.Y.); (Z.C.); (Y.Y.)
- Collaborative Innovation Center of Chemical Science and Engineering (Tianjin), Tianjin University, Tianjin 300072, China
| | - Yingjin Yuan
- Frontier Science Center for Synthetic Biology and Key Laboratory of Systems Bioengineering (Ministry of Education), School of Chemical Engineering and Technology, Tianjin University, Tianjin 300072, China; (X.Q.); (W.Y.); (Z.C.); (Y.Y.)
- Collaborative Innovation Center of Chemical Science and Engineering (Tianjin), Tianjin University, Tianjin 300072, China
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29
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Qi X, Ma Y, Chang H, Li B, Ding M, Yuan Y. Evaluation of PET Degradation Using Artificial Microbial Consortia. Front Microbiol 2021; 12:778828. [PMID: 35003008 PMCID: PMC8733400 DOI: 10.3389/fmicb.2021.778828] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2021] [Accepted: 12/06/2021] [Indexed: 01/30/2023] Open
Abstract
Polyethylene terephthalate (PET) biodegradation is regarded as an environmentally friendly degradation method. In this study, an artificial microbial consortium composed of Rhodococcus jostii, Pseudomonas putida and two metabolically engineered Bacillus subtilis was constructed to degrade PET. First, a two-species microbial consortium was constructed with two engineered B. subtilis that could secrete PET hydrolase (PETase) and monohydroxyethyl terephthalate hydrolase (MHETase), respectively; it could degrade 13.6% (weight loss) of the PET film within 7 days. A three-species microbial consortium was further obtained by adding R. jostii to reduce the inhibition caused by terephthalic acid (TPA), a breakdown product of PET. The weight of PET film was reduced by 31.2% within 3 days, achieving about 17.6% improvement compared with the two-species microbial consortium. Finally, P. putida was introduced to reduce the inhibition caused by ethylene glycol (EG), another breakdown product of PET, obtaining a four-species microbial consortium. With the four-species consortium, the weight loss of PET film reached 23.2% under ambient temperature. This study constructed and evaluated the artificial microbial consortia in PET degradation, which demonstrated the great potential of artificial microbial consortia in the utilization of complex substrates, providing new insights for biodegradation of complex polymers.
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Affiliation(s)
- Xinhua Qi
- Key Laboratory of Systems Bioengineering (Ministry of Education), Frontier Science Center for Synthetic Biology, School of Chemical Engineering and Technology, Tianjin University, Tianjin, China
- Collaborative Innovation Center of Chemical Science and Engineering (Tianjin), Tianjin University, Tianjin, China
| | - Yuan Ma
- Key Laboratory of Systems Bioengineering (Ministry of Education), Frontier Science Center for Synthetic Biology, School of Chemical Engineering and Technology, Tianjin University, Tianjin, China
- Collaborative Innovation Center of Chemical Science and Engineering (Tianjin), Tianjin University, Tianjin, China
| | - Hanchen Chang
- Key Laboratory of Systems Bioengineering (Ministry of Education), Frontier Science Center for Synthetic Biology, School of Chemical Engineering and Technology, Tianjin University, Tianjin, China
- Collaborative Innovation Center of Chemical Science and Engineering (Tianjin), Tianjin University, Tianjin, China
| | - Bingzhi Li
- Key Laboratory of Systems Bioengineering (Ministry of Education), Frontier Science Center for Synthetic Biology, School of Chemical Engineering and Technology, Tianjin University, Tianjin, China
- Collaborative Innovation Center of Chemical Science and Engineering (Tianjin), Tianjin University, Tianjin, China
| | - Mingzhu Ding
- Key Laboratory of Systems Bioengineering (Ministry of Education), Frontier Science Center for Synthetic Biology, School of Chemical Engineering and Technology, Tianjin University, Tianjin, China
- Collaborative Innovation Center of Chemical Science and Engineering (Tianjin), Tianjin University, Tianjin, China
| | - Yingjin Yuan
- Key Laboratory of Systems Bioengineering (Ministry of Education), Frontier Science Center for Synthetic Biology, School of Chemical Engineering and Technology, Tianjin University, Tianjin, China
- Collaborative Innovation Center of Chemical Science and Engineering (Tianjin), Tianjin University, Tianjin, China
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Abda EM, Muleta A, Tafesse M, Prabhu SV, Aemro A. Recent endeavors in microbial remediation of micro- and nanoplastics. PHYSICAL SCIENCES REVIEWS 2021. [DOI: 10.1515/psr-2021-0061] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Abstract
Petrochemical plastics are frequently utilized in our daily lives for various purposes such as packaging and transportation, but their burden on the environment is considered one of the most man-made pollution crises. These pollutants are slowly fragmented in the environment into microplastics and nanoplastics by consolidated actions of abiotic and biotic factors. Microplastics and nanoplastics can easily be dispersed in the atmosphere and be harmful to all kinds of life. As a result, the remediation of micro- and nanoplastics has recently received a tremendous research impetus in the realm of an ecologically benign approach, notably microbial-based remediation. Thus, the current article looks at the formation, properties, analysis, and biological effects of micro- and nanoplastics. The content is then streamlined towards a comprehensive discussion on microbial-mediated degradation of microplastics and nanoplastics, with an emphasis on front-line bacteria and enzymes, as well as remediation mechanisms. Further, technologies for the removal of microplastics and nanoplastics from the environment are presented for possible remedial considerations. An attempt is also made to highlight the practical snags of microbial plastic degradation while aiming to alleviate the environmental burden of plastic waste.
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Affiliation(s)
- Ebrahim M. Abda
- Department of Biotechnology , Addis Ababa Science and Technology University , P.O. Box 16417, Akaki Kality , Addis Ababa , Ethiopia
- Centre of Excellence- Biotechnology and Bioprocessing, Addis Ababa Science and Technology University , P.O. Box 16417, Akaki Kality , Addis Ababa , Ethiopia
| | - Atsede Muleta
- Department of Biology , University of Gondar , P.O. Box 196 , Gondar , Ethiopia
| | - Mesfin Tafesse
- Department of Biotechnology , Addis Ababa Science and Technology University , P.O. Box 16417, Akaki Kality , Addis Ababa , Ethiopia
- Centre of Excellence- Biotechnology and Bioprocessing, Addis Ababa Science and Technology University , P.O. Box 16417, Akaki Kality , Addis Ababa , Ethiopia
| | - Sundramurthy Venkatesa Prabhu
- Department of Chemical Engineering , Addis Ababa Science and Technology University , P.O. Box 16417, Akaki Kality , Addis Ababa , Ethiopia
| | - Afework Aemro
- Department of Environmental Engineering , Addis Ababa Science and Technology University , P.O. Box 16417, Akaki Kality , Addis Ababa , Ethiopia
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Tamoor M, Samak NA, Jia Y, Mushtaq MU, Sher H, Bibi M, Xing J. Potential Use of Microbial Enzymes for the Conversion of Plastic Waste Into Value-Added Products: A Viable Solution. Front Microbiol 2021; 12:777727. [PMID: 34917057 PMCID: PMC8670383 DOI: 10.3389/fmicb.2021.777727] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2021] [Accepted: 11/04/2021] [Indexed: 01/24/2023] Open
Abstract
The widespread use of commercial polymers composed of a mixture of polylactic acid and polyethene terephthalate (PLA-PET) in bottles and other packaging materials has caused a massive environmental crisis. The valorization of these contaminants via cost-effective technologies is urgently needed to achieve a circular economy. The enzymatic hydrolysis of PLA-PET contaminants plays a vital role in environmentally friendly strategies for plastic waste recycling and degradation. In this review, the potential roles of microbial enzymes for solving this critical problem are highlighted. Various enzymes involved in PLA-PET recycling and bioconversion, such as PETase and MHETase produced by Ideonella sakaiensis; esterases produced by Bacillus and Nocardia; lipases produced by Thermomyces lanuginosus, Candida antarctica, Triticum aestivum, and Burkholderia spp.; and leaf-branch compost cutinases are critically discussed. Strategies for the utilization of PLA-PET's carbon content as C1 building blocks were investigated for the production of new plastic monomers and different value-added products, such as cyclic acetals, 1,3-propanediol, and vanillin. The bioconversion of PET-PLA degradation monomers to polyhydroxyalkanoate biopolymers by Pseudomonas and Halomonas strains was addressed in detail. Different solutions to the production of biodegradable plastics from food waste, agricultural residues, and polyhydroxybutyrate (PHB)-accumulating bacteria were discussed. Fuel oil production via PLA-PET thermal pyrolysis and possible hybrid integration techniques for the incorporation of thermostable plastic degradation enzymes for the conversion into fuel oil is explained in detail.
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Affiliation(s)
- Muhammad Tamoor
- CAS Key Laboratory of Green Process and Engineering, State Key Laboratory of Biochemical Engineering, Institute of Process Engineering, Chinese Academy of Sciences, Beijing, China
- College of Chemical Engineering, University of Chinese Academy of Sciences, Beijing, China
| | - Nadia A. Samak
- CAS Key Laboratory of Green Process and Engineering, State Key Laboratory of Biochemical Engineering, Institute of Process Engineering, Chinese Academy of Sciences, Beijing, China
- Biofilm Centre, Aquatic Microbiology Department, Faculty of Chemistry, University Duisburg-Essen, Essen, Germany
| | - Yunpu Jia
- CAS Key Laboratory of Green Process and Engineering, State Key Laboratory of Biochemical Engineering, Institute of Process Engineering, Chinese Academy of Sciences, Beijing, China
- College of Chemical Engineering, University of Chinese Academy of Sciences, Beijing, China
| | - Muhammad Umar Mushtaq
- CAS Key Laboratory of Green Process and Engineering, State Key Laboratory of Biochemical Engineering, Institute of Process Engineering, Chinese Academy of Sciences, Beijing, China
- College of Chemical Engineering, University of Chinese Academy of Sciences, Beijing, China
- Department of Chemical Engineering, Wah Engineering College, University of Wah, Wah Cantt, Pakistan
| | - Hassan Sher
- CAS Key Laboratory of Green Process and Engineering, State Key Laboratory of Biochemical Engineering, Institute of Process Engineering, Chinese Academy of Sciences, Beijing, China
- College of Chemical Engineering, University of Chinese Academy of Sciences, Beijing, China
| | - Maryam Bibi
- Department of Chemical Engineering, Wah Engineering College, University of Wah, Wah Cantt, Pakistan
| | - Jianmin Xing
- CAS Key Laboratory of Green Process and Engineering, State Key Laboratory of Biochemical Engineering, Institute of Process Engineering, Chinese Academy of Sciences, Beijing, China
- College of Chemical Engineering, University of Chinese Academy of Sciences, Beijing, China
- Chemistry and Chemical Engineering Guangdong Laboratory, Shantou, China
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Dai L, Qu Y, Hu Y, Min J, Yu X, Chen CC, Huang JW, Guo RT. Catalytically inactive lytic polysaccharide monooxygenase PcAA14A enhances the enzyme-mediated hydrolysis of polyethylene terephthalate. Int J Biol Macromol 2021; 190:456-462. [PMID: 34499955 DOI: 10.1016/j.ijbiomac.2021.09.005] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2021] [Revised: 08/31/2021] [Accepted: 09/01/2021] [Indexed: 10/20/2022]
Abstract
The massive accumulation of polyethylene terephthalate (PET) in the global ecosystem is a growing environmental crisis. Development of environmental friendly strategies to achieve enzyme-catalyzed PET degradation has attracted tremendous attention. In this study, we demonstrated the synergistic effects of combining a specific PET-degrading enzyme IsPETaseEHA variant from PET-assimilating bacterium Ideonella sakaiensis and a lytic polysaccharide monooxygenase from a white-rot fungus Pycnoporus coccineus (PcAA14A) in PET degradation. We found that the presence of PcAA14A alone did not result in PET hydrolysis, but its presence could stimulate IsPETaseEHA-mediated hydrolytic efficiency by up to 1.3-fold. Notably, the stimulatory effects of PcAA14A on IsPETaseEHA-catalyzed PET hydrolysis were found to be independent of monooxygenase activity. Dose-effects of IsPETaseEHA and PcAA14A on PET hydrolysis were observed, with the optimal concentrations being determined to 25 μg/mL and 0.25 μg/mL, respectively. In the 5-day PET hydrolysis experiment, 1097 μM hydrolysis products were produced by adding the optimized concentrations of IsPETaseEHA and PcAA14A, which was 27.7% higher than those were produced by IsPETaseEHA alone. Our study reports the first time that PcAA14A could stimulate the IsPETaseEHA-mediated PET hydrolysis through a monooxygenase activity independent manner.
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Affiliation(s)
- Longhai Dai
- State Key Laboratory of Biocatalysis and Enzyme Engineering, Hubei Collaborative Innovation Center for Green Transformation of Bio-Resources, Hubei Key Laboratory of Industrial Biotechnology, Hubei Key Laboratory of Regional Development and Environmental Response, Faculty of Resources and Environmental Science, School of Life Sciences, Hubei University, Wuhan, 430062, PR China
| | - Yingying Qu
- State Key Laboratory of Biocatalysis and Enzyme Engineering, Hubei Collaborative Innovation Center for Green Transformation of Bio-Resources, Hubei Key Laboratory of Industrial Biotechnology, Hubei Key Laboratory of Regional Development and Environmental Response, Faculty of Resources and Environmental Science, School of Life Sciences, Hubei University, Wuhan, 430062, PR China
| | - Yumei Hu
- State Key Laboratory of Biocatalysis and Enzyme Engineering, Hubei Collaborative Innovation Center for Green Transformation of Bio-Resources, Hubei Key Laboratory of Industrial Biotechnology, Hubei Key Laboratory of Regional Development and Environmental Response, Faculty of Resources and Environmental Science, School of Life Sciences, Hubei University, Wuhan, 430062, PR China
| | - Jian Min
- State Key Laboratory of Biocatalysis and Enzyme Engineering, Hubei Collaborative Innovation Center for Green Transformation of Bio-Resources, Hubei Key Laboratory of Industrial Biotechnology, Hubei Key Laboratory of Regional Development and Environmental Response, Faculty of Resources and Environmental Science, School of Life Sciences, Hubei University, Wuhan, 430062, PR China
| | - Xuejing Yu
- State Key Laboratory of Biocatalysis and Enzyme Engineering, Hubei Collaborative Innovation Center for Green Transformation of Bio-Resources, Hubei Key Laboratory of Industrial Biotechnology, Hubei Key Laboratory of Regional Development and Environmental Response, Faculty of Resources and Environmental Science, School of Life Sciences, Hubei University, Wuhan, 430062, PR China
| | - Chun-Chi Chen
- State Key Laboratory of Biocatalysis and Enzyme Engineering, Hubei Collaborative Innovation Center for Green Transformation of Bio-Resources, Hubei Key Laboratory of Industrial Biotechnology, Hubei Key Laboratory of Regional Development and Environmental Response, Faculty of Resources and Environmental Science, School of Life Sciences, Hubei University, Wuhan, 430062, PR China
| | - Jian-Wen Huang
- State Key Laboratory of Biocatalysis and Enzyme Engineering, Hubei Collaborative Innovation Center for Green Transformation of Bio-Resources, Hubei Key Laboratory of Industrial Biotechnology, Hubei Key Laboratory of Regional Development and Environmental Response, Faculty of Resources and Environmental Science, School of Life Sciences, Hubei University, Wuhan, 430062, PR China.
| | - Rey-Ting Guo
- State Key Laboratory of Biocatalysis and Enzyme Engineering, Hubei Collaborative Innovation Center for Green Transformation of Bio-Resources, Hubei Key Laboratory of Industrial Biotechnology, Hubei Key Laboratory of Regional Development and Environmental Response, Faculty of Resources and Environmental Science, School of Life Sciences, Hubei University, Wuhan, 430062, PR China.
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Allouzi MMA, Tang DYY, Chew KW, Rinklebe J, Bolan N, Allouzi SMA, Show PL. Micro (nano) plastic pollution: The ecological influence on soil-plant system and human health. THE SCIENCE OF THE TOTAL ENVIRONMENT 2021; 788:147815. [PMID: 34034191 DOI: 10.1016/j.scitotenv.2021.147815] [Citation(s) in RCA: 69] [Impact Index Per Article: 23.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/08/2021] [Revised: 04/23/2021] [Accepted: 05/13/2021] [Indexed: 05/27/2023]
Abstract
Global plastic pollution has been a serious problem since many years and micro (nano) plastics (MNPs) have gained attention from researchers around the world. This is because MNPs able to exhibit toxicology and interact with potentially toxic elements (PTEs) in the environment, causing soil toxicity. The influences of MNPs on the soil systems and plant crops have been overlooked despite that MNPs can accumulate in the plant root system and generate detrimental impacts to the terrestrial environments. The consumption of these MNPs-contaminated plants or fruits by humans and animals will eventually lead to health deterioration. The identification and measurement of MNPs in various soil samples is challenging, making the understanding of the fate, environmental and ecological of MNPs in terrestrial ecosystem is limited. Prior to sample assessment, it is necessary to isolate the plastic particles from the environment samples, concentrate the plastic particles for analysis purpose to meet detection limit for analytical instrument. The isolation and pre-concentrated steps are challenging and may cause sample loss. Herein, this article reviews MNPs, including their fate in the environment and toxic effects exhibited towards soil microorganisms, plants and humans along with the interaction of MNPs with PTEs. In addition, various analysis methods of MNPs and management of MNPs as well as the crucial challenges and future research studies in combating MNPs in soil system are also discussed.
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Affiliation(s)
- Mintallah Mousa A Allouzi
- Department of Chemical and Environmental Engineering, Faculty of Science and Engineering, University of Nottingham Malaysia, Jalan Broga, 43500 Semenyih, Selangor Darul Ehsan, Malaysia
| | - Doris Ying Ying Tang
- Department of Chemical and Environmental Engineering, Faculty of Science and Engineering, University of Nottingham Malaysia, Jalan Broga, 43500 Semenyih, Selangor Darul Ehsan, Malaysia
| | - Kit Wayne Chew
- School of Energy and Chemical Engineering, Xiamen University Malaysia, Jalan Sunsuria, Bandar Sunsuria, 43900 Sepang, Selangor Darul Ehsan, Malaysia; College of Chemistry and Chemical Engineering, Xiamen University, Xiamen 361005, Fujian, China
| | - Jörg Rinklebe
- School of Architecture and Civil Engineering, Laboratory of Soil- and Groundwater-Management, Institute of Foundation Engineering, Water- and Waste-Management, University of Wuppertal, Wuppertal, Germany; Department of Environment, Energy and Geoinformatics, Sejong University, Seoul, Republic of Korea
| | - Nanthi Bolan
- College of Engineering, Science and Environment, The University of Newcastle (UON), Callaghan, NSW 2308, Australia
| | - Safa Mousa A Allouzi
- Department of Medicine, Faculty of Medicine, Bioscience, and Nursing, MAHSA University, Jln SP 2, Bandar Saujana Putra, 42610 Jenjarom, Selangor, Malaysia
| | - Pau Loke Show
- Department of Chemical and Environmental Engineering, Faculty of Science and Engineering, University of Nottingham Malaysia, Jalan Broga, 43500 Semenyih, Selangor Darul Ehsan, Malaysia.
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Gao R, Pan H, Lian J. Recent advances in the discovery, characterization, and engineering of poly(ethylene terephthalate) (PET) hydrolases. Enzyme Microb Technol 2021; 150:109868. [PMID: 34489027 DOI: 10.1016/j.enzmictec.2021.109868] [Citation(s) in RCA: 29] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2021] [Revised: 07/01/2021] [Accepted: 07/06/2021] [Indexed: 12/28/2022]
Abstract
Poly(ethylene terephthalate) (PET) is a class of polyester plastic composed of terephthalic acid (TPA) and ethylene glycol (EG). The accumulation of large amount of PET waste has resulted in severe environmental and health problems. Microbial polyester hydrolases with the ability to degrade PET provide an economy- and environment-friendly approach for the treatment of PET waste. In recent years, many PET hydrolases have been discovered and characterized from various microorganisms and engineered for better performance under practical application conditions. Here, recent progress in the discovery, characterization, and enzymatic mechanism elucidation of PET hydrolases is firstly reviewed. Then, structure-guided protein engineering of PET hydrolases with increased enzymatic activities, expanded substrate specificity, as well as improved protein stability is summarized. In addition, strategies for efficient expression of recombinant PET hydrolases, including secretory expression and cell-surface display, are briefly introduced. This review is concluded with future perspectives in biodegradation and subsequent biotransformation of PET wastes to produce value-added compounds.
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Affiliation(s)
- Rui Gao
- Key Laboratory of Biomass Chemical Engineering of Ministry of Education, College of Chemical and Biological Engineering, Zhejiang University, Hangzhou, 310027, China
| | - Haojie Pan
- Key Laboratory of Biomass Chemical Engineering of Ministry of Education, College of Chemical and Biological Engineering, Zhejiang University, Hangzhou, 310027, China
| | - Jiazhang Lian
- Key Laboratory of Biomass Chemical Engineering of Ministry of Education, College of Chemical and Biological Engineering, Zhejiang University, Hangzhou, 310027, China; Hangzhou Global Scientific and Technological Innovation Center, Zhejiang University, Hangzhou, 310027, China.
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Development of a Targeted Gene Disruption System in the Poly(Ethylene Terephthalate)-Degrading Bacterium Ideonella sakaiensis and Its Applications to PETase and MHETase Genes. Appl Environ Microbiol 2021; 87:e0002021. [PMID: 34260304 DOI: 10.1128/aem.00020-21] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023] Open
Abstract
Poly(ethylene terephthalate) (PET) is a commonly used synthetic plastic; however, its nonbiodegradability results in a large amount of waste accumulation that has a negative impact on the environment. Recently, a PET-degrading bacterium, Ideonella sakaiensis 201-F6 strain, was isolated, and the enzymes involved in PET digestion, PET hydrolase (PETase), and mono(2-hydroxyethyl) terephthalic acid (MHET) hydrolase (MHETase) were identified. Despite the great potentials of I. sakaiensis in bioremediation and biorecycling, approaches to studying this bacterium remain limited. In this study, to enable the functional analysis of PETase and MHETase genes in vivo, we have developed a gene disruption system in I. sakaiensis. The pT18mobsacB-based disruption vector harboring directly connected 5'- and 3'-flanking regions of the target gene for homologous recombination was introduced into I. sakaiensis cells via conjugation. First, we deleted the orotidine 5'-phosphate decarboxylase gene (pyrF) from the genome of the wild-type strain, producing the ΔpyrF strain with 5-fluoroorotic acid (5-FOA) resistance. Next, using the ΔpyrF strain as a parent strain and pyrF as a counterselection marker, we disrupted the genes for PETase and MHETase. The growth of both Δpetase and Δmhetase strains on terephthalic acid (TPA; one of the PET hydrolytic products) was comparable to that of the parent strain. However, these mutant strains dramatically decreased the growth level on PET to that on a no-carbon source. Moreover, the Δpetase strain completely abolished PET degradation capacity. These results demonstrate that PETase and MHETase are essential for I. sakaiensis metabolism of PET. IMPORTANCE The poly(ethylene terephthalate) (PET)-degrading bacterium Ideonella sakaiensis possesses two unique enzymes able to serve in PET hydrolysis. PET hydrolase (PETase) hydrolyzes PET into mono(2-hydroxyethyl) terephthalic acid (MHET), and MHET hydrolase (MHETase) hydrolyzes MHET into terephthalic acid (TPA) and ethylene glycol (EG). These enzymes have attracted global attention, as they have potential to be used for bioconversion of PET. Compared to many in vitro studies, including biochemical and crystal structure analyses, few in vivo studies have been reported. Here, we developed a targeted gene disruption system in I. sakaiensis, which was then applied for constructing Δpetase and Δmhetase strains. Growth of these disruptants revealed that PETase is the sole enzyme responsible for PET degradation in I. sakaiensis, while PETase and MHETase play essential roles in its PET assimilation.
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Sagong HY, Son HF, Seo H, Hong H, Lee D, Kim KJ. Implications for the PET decomposition mechanism through similarity and dissimilarity between PETases from Rhizobacter gummiphilus and Ideonella sakaiensis. JOURNAL OF HAZARDOUS MATERIALS 2021; 416:126075. [PMID: 34492896 DOI: 10.1016/j.jhazmat.2021.126075] [Citation(s) in RCA: 28] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/10/2021] [Revised: 04/22/2021] [Accepted: 05/05/2021] [Indexed: 06/13/2023]
Abstract
The development of a superb polyethylene terephthalate (PET) hydrolyzing enzyme requires an accurate understanding of the PET decomposition mechanism. However, studies on PET degrading enzymes, including the PET hydrolase from Ideonella sakaiensis (IsPETase), have not provided sufficient knowledge of the molecular mechanisms for the hardly accessible substrate. Here, we report a novel PET hydrolase from Rhizobacter gummiphilus (RgPETase), which has a hydrolyzing activity similar to IsPETase toward microcrystalline PET but distinct behavior toward low crystallinity PET film. Structural analysis of RgPETase reveals that the enzyme shares the key structural features of IsPETase for high PET hydrolysis activity but has distinguished structures at the surface-exposed regions. RgPETase shows a unique conformation of the wobbling tryptophan containing loop (WW-loop) and change of the electrostatic surface charge on the loop dramatically affects the PET-degrading activity. We further show that effect of the electrostatic surface charge to the activity varies depending on locations. This work provides valuable information underlying the uncovered PET decomposition mechanism.
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Affiliation(s)
- Hye-Young Sagong
- School of Life Sciences, BK21 FOUR KNU Creative BioResearch Group, Kyungpook National University, Daegu 41566, Republic of Korea; KNU Institute for Microorganisms, Kyungpook National University, Daegu 41566, Republic of Korea
| | - Hyeoncheol Francis Son
- School of Life Sciences, BK21 FOUR KNU Creative BioResearch Group, Kyungpook National University, Daegu 41566, Republic of Korea; KNU Institute for Microorganisms, Kyungpook National University, Daegu 41566, Republic of Korea
| | - Hogyun Seo
- School of Life Sciences, BK21 FOUR KNU Creative BioResearch Group, Kyungpook National University, Daegu 41566, Republic of Korea; Pohang Accelerator Laboratory, Pohang University of Science and Technology, Pohang, Republic of Korea
| | - Hwaseok Hong
- School of Life Sciences, BK21 FOUR KNU Creative BioResearch Group, Kyungpook National University, Daegu 41566, Republic of Korea; KNU Institute for Microorganisms, Kyungpook National University, Daegu 41566, Republic of Korea
| | - Donghoon Lee
- School of Life Sciences, BK21 FOUR KNU Creative BioResearch Group, Kyungpook National University, Daegu 41566, Republic of Korea; KNU Institute for Microorganisms, Kyungpook National University, Daegu 41566, Republic of Korea
| | - Kyung-Jin Kim
- School of Life Sciences, BK21 FOUR KNU Creative BioResearch Group, Kyungpook National University, Daegu 41566, Republic of Korea; KNU Institute for Microorganisms, Kyungpook National University, Daegu 41566, Republic of Korea.
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Cui L, Qiu Y, Liang Y, Du C, Dong W, Cheng C, He B. Excretory expression of IsPETase in E. coli by an enhancer of signal peptides and enhanced PET hydrolysis. Int J Biol Macromol 2021; 188:568-575. [PMID: 34371048 DOI: 10.1016/j.ijbiomac.2021.08.012] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2021] [Revised: 07/10/2021] [Accepted: 08/03/2021] [Indexed: 10/20/2022]
Abstract
The PET hydrolase from Ideonella sakaiensis (IsPETase) is efficient for PET degradation, which provides a promising solution for environmental contamination by plastics. This study focuses on improving the excretion of IsPETase from E. coli by signal peptide (SP) engineering. A SP enhancer B1 (MERACVAV) was fused to the N-terminal of commonly-used SP (PelB, MalE, LamB, and OmpA) to mediate excretion of IsPETase. Strikingly, the modified SP B1OmpA, B1PelB, and B1MalE significantly increased the excretion of IsPETase, while IsPETase was basically expressed in periplasmic space without enhancer B1. The excretion efficiency of IsPETase mediated by B1PelB was improved by 62 folds compared to that of PelB. The hydrolysis of PET by crude IsPETase in culture solution was also enhanced. Furthermore, the amount of released MHET/TPA from PET by IsPETase was increased by 2.7 folds with pre-incubation of hydrophobin HFBII. Taken together, this work may provide a feasible strategy for the excretion and application of the IsPETase.
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Affiliation(s)
- Lupeng Cui
- College of Biotechnology and Pharmaceutical Engineering, Nanjing Tech University, No. 30 Puzhu South Road, Nanjing 211816, China
| | - Yumeng Qiu
- School of Pharmaceutical Sciences, Nanjing Tech University, No. 30 Puzhu South Road, Nanjing 211816, China
| | - Yu Liang
- 2011 College, Nanjing Tech University, No. 30 Puzhu South Road, Nanjing 211816, China
| | - Chunjie Du
- 2011 College, Nanjing Tech University, No. 30 Puzhu South Road, Nanjing 211816, China
| | - Weiliang Dong
- College of Biotechnology and Pharmaceutical Engineering, Nanjing Tech University, No. 30 Puzhu South Road, Nanjing 211816, China
| | - Cheng Cheng
- School of Pharmaceutical Sciences, Nanjing Tech University, No. 30 Puzhu South Road, Nanjing 211816, China.
| | - Bingfang He
- College of Biotechnology and Pharmaceutical Engineering, Nanjing Tech University, No. 30 Puzhu South Road, Nanjing 211816, China; School of Pharmaceutical Sciences, Nanjing Tech University, No. 30 Puzhu South Road, Nanjing 211816, China.
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Gercke D, Furtmann C, Tozakidis IEP, Jose J. Highly Crystalline Post‐Consumer PET Waste Hydrolysis by Surface Displayed PETase Using a Bacterial Whole‐Cell Biocatalyst. ChemCatChem 2021. [DOI: 10.1002/cctc.202100443] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Affiliation(s)
- David Gercke
- Institut für Pharmazeutische und Medizinische Chemie PharmaCampus Westfälische Wilhelms-Universität Münster Corrensstrasse 48 48149 Münster Germany
| | - Christoph Furtmann
- Institut für Pharmazeutische und Medizinische Chemie PharmaCampus Westfälische Wilhelms-Universität Münster Corrensstrasse 48 48149 Münster Germany
| | - Iasson E. P. Tozakidis
- Institut für Pharmazeutische und Medizinische Chemie PharmaCampus Westfälische Wilhelms-Universität Münster Corrensstrasse 48 48149 Münster Germany
| | - Joachim Jose
- Institut für Pharmazeutische und Medizinische Chemie PharmaCampus Westfälische Wilhelms-Universität Münster Corrensstrasse 48 48149 Münster Germany
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Production of proteins and commodity chemicals using engineered Bacillus subtilis platform strain. Essays Biochem 2021; 65:173-185. [PMID: 34028523 DOI: 10.1042/ebc20210011] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2021] [Revised: 05/02/2021] [Accepted: 05/06/2021] [Indexed: 12/19/2022]
Abstract
Currently, increasing demand of biochemicals produced from renewable resources has motivated researchers to seek microbial production strategies instead of traditional chemical methods. As a microbial platform, Bacillus subtilis possesses many advantages including the generally recognized safe status, clear metabolic networks, short growth cycle, mature genetic editing methods and efficient protein secretion systems. Engineered B. subtilis strains are being increasingly used in laboratory research and in industry for the production of valuable proteins and other chemicals. In this review, we first describe the recent advances of bioinformatics strategies during the research and applications of B. subtilis. Secondly, the applications of B. subtilis in enzymes and recombinant proteins production are summarized. Further, the recent progress in employing metabolic engineering and synthetic biology strategies in B. subtilis platform strain to produce commodity chemicals is systematically introduced and compared. Finally, the major limitations for the further development of B. subtilis platform strain and possible future directions for its research are also discussed.
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Dai L, Qu Y, Huang JW, Hu Y, Hu H, Li S, Chen CC, Guo RT. Enhancing PET hydrolytic enzyme activity by fusion of the cellulose-binding domain of cellobiohydrolase I from Trichoderma reesei. J Biotechnol 2021; 334:47-50. [PMID: 34044062 DOI: 10.1016/j.jbiotec.2021.05.006] [Citation(s) in RCA: 39] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2021] [Revised: 03/10/2021] [Accepted: 05/21/2021] [Indexed: 11/18/2022]
Abstract
The large amounts of polyethylene terephthalate (PET) that enter and accumulate in the environment have posed a serious threat to global ecosystems and human health. A PET hydrolase from PET-assimilating bacterium Ideonella sakaiensis (IsPETase) that exhibits superior PET hydrolytic activity at mild conditions is attracting enormous attention in development of plastic biodegrading strategies. In order to enhance the PET hydrolysis capacity of IsPETase, we selected several polymer-binding domains that can adhere to a hydrophobic polymer surface and fused these to a previously engineered IsPETaseS121E/D186H/R280A (IsPETaseEHA) variant. We found that fusing a cellulose-binding domain (CBM) of cellobiohydrolase I from Trichoderma reesei onto the C-terminus of IsPETaseEHA showed a stimulatory effect on enzymatic hydrolysis of PET. Compared to the parental enzyme, IsPETaseEHA_CBM exhibited 71.5 % and 44.5 % higher hydrolytic activity at 30 ℃ and 40 ℃, respectively. The catalytic activity of IsPETaseEHA_CBM was increased by 86 % when the protein concentration was increased from 2.5 μg/mL to 20 μg/mL. These findings suggest that the fusion of polymer-binding module to IsPETase is a promising strategy to stimulate the enzymatic hydrolysis of PET.
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Affiliation(s)
- Longhai Dai
- State Key Laboratory of Biocatalysis and Enzyme Engineering, Hubei Collaborative Innovation Center for Green Transformation of Bio-Resources, Hubei Key Laboratory of Industrial Biotechnology, School of Life Sciences, Hubei University, Wuhan, 430062, PR China
| | - Yingying Qu
- State Key Laboratory of Biocatalysis and Enzyme Engineering, Hubei Collaborative Innovation Center for Green Transformation of Bio-Resources, Hubei Key Laboratory of Industrial Biotechnology, School of Life Sciences, Hubei University, Wuhan, 430062, PR China
| | - Jian-Wen Huang
- State Key Laboratory of Biocatalysis and Enzyme Engineering, Hubei Collaborative Innovation Center for Green Transformation of Bio-Resources, Hubei Key Laboratory of Industrial Biotechnology, School of Life Sciences, Hubei University, Wuhan, 430062, PR China
| | - Yumei Hu
- State Key Laboratory of Biocatalysis and Enzyme Engineering, Hubei Collaborative Innovation Center for Green Transformation of Bio-Resources, Hubei Key Laboratory of Industrial Biotechnology, School of Life Sciences, Hubei University, Wuhan, 430062, PR China
| | - Hebing Hu
- State Key Laboratory of Biocatalysis and Enzyme Engineering, Hubei Collaborative Innovation Center for Green Transformation of Bio-Resources, Hubei Key Laboratory of Industrial Biotechnology, School of Life Sciences, Hubei University, Wuhan, 430062, PR China
| | - Siyu Li
- State Key Laboratory of Biocatalysis and Enzyme Engineering, Hubei Collaborative Innovation Center for Green Transformation of Bio-Resources, Hubei Key Laboratory of Industrial Biotechnology, School of Life Sciences, Hubei University, Wuhan, 430062, PR China
| | - Chun-Chi Chen
- State Key Laboratory of Biocatalysis and Enzyme Engineering, Hubei Collaborative Innovation Center for Green Transformation of Bio-Resources, Hubei Key Laboratory of Industrial Biotechnology, School of Life Sciences, Hubei University, Wuhan, 430062, PR China.
| | - Rey-Ting Guo
- State Key Laboratory of Biocatalysis and Enzyme Engineering, Hubei Collaborative Innovation Center for Green Transformation of Bio-Resources, Hubei Key Laboratory of Industrial Biotechnology, School of Life Sciences, Hubei University, Wuhan, 430062, PR China.
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Dey TK, Uddin ME, Jamal M. Detection and removal of microplastics in wastewater: evolution and impact. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2021; 28:16925-16947. [PMID: 33634402 PMCID: PMC7906573 DOI: 10.1007/s11356-021-12943-5] [Citation(s) in RCA: 66] [Impact Index Per Article: 22.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/18/2020] [Accepted: 02/09/2021] [Indexed: 05/05/2023]
Abstract
The pervasiveness of microplastics in aquatic ecosystems has become a major environmental issue in recent years. The gradual dumping of plastic wastes, inadequate standard detection methods with specific removal techniques, and slow disposal rate of microplastics make it ubiquitous in the environment. Evidence shows that microplastics act as a potential vector by adsorbing different heavy metals, pathogens, and other chemical additives widely used in different raw plastic production. Microplastics are ingested by aquatic creatures such as fish and different crustaceans, and finally, people ingest them at the tertiary level of the food chain. This phenomenon is responsible for blocking the digestion tracts, disturbing the digestive behavior, finally decreasing the reproductive growth of entire living organisms. Because of these consequences, microplastics have become an increasing concern as a newly emerging potential threat, and therefore, the control of microplastics in aquatic media is required. This paper provides a critical analysis of existing and newly developed methods for detecting and separating microplastics from discharged wastewater, which are the ultimate challenges in the microplastic treatment systems. A critical study on the effect of microplastics on aquatic organisms and human health is also discussed. Thus, this analysis provides a complete understanding of entire strategies for detecting and removing microplastics and their associated issues to ensure a waste discharge standard to minimize the ultimate potential impact in aquatic environments.
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Affiliation(s)
- Thuhin K Dey
- Department of Leather Engineering, Faculty of Mechanical Engineering, Khulna University of Engineering & Technology, Khulna, 9203, Bangladesh
| | - Md Elias Uddin
- Department of Leather Engineering, Faculty of Mechanical Engineering, Khulna University of Engineering & Technology, Khulna, 9203, Bangladesh
| | - Mamun Jamal
- Department of Chemistry, Faculty of Civil Engineering, Khulna University of Engineering & Technology, Khulna, 9203, Bangladesh.
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Maity W, Maity S, Bera S, Roy A. Emerging Roles of PETase and MHETase in the Biodegradation of Plastic Wastes. Appl Biochem Biotechnol 2021; 193:2699-2716. [PMID: 33797026 DOI: 10.1007/s12010-021-03562-4] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2020] [Accepted: 03/22/2021] [Indexed: 11/26/2022]
Abstract
Polyethylene terephthalate (PET) is extensively used in plastic products, and its accumulation in the environment has become a global concern. Being a non-degradable pollutant, a tremendous quantity of PET-bearing plastic materials have already accumulated in the environment, posing severe challenges towards the existence of various endangered species and consequently threatening the ecosystem and biodiversity. While conventional recycling and remediation methodologies so far have been ineffective in formulating a "green" degradation protocol, the bioremediation strategies-though nascent-are exhibiting greater promises towards achieving the target. Very recently, a novel bacterial strain called Ideonella sakaiensis 201-F6 has been discovered that produces a couple of unique enzymes, polyethylene terephthalate hydrolase and mono(2-hydroxyethyl) terephthalic acid hydrolase, enabling the bacteria to utilize PET as their sole carbon source. With a detailed understanding of the protein structure of these enzymes, possibilities for their optimization as PET degrading agents have started to emerge. In both proteins, several amino acids have been identified that are not only instrumental for catalysis but also provide avenues for the applications of genetic engineering strategies to improve the catalytic efficiencies of the enzymes. In this review, we focused on such unique structural features of these two enzymes and discussed their potential as molecular tools that can essentially become instrumental towards the development of sustainable bioremediation strategies. Degradation PET by wild type and genetically engineered PETase and MHETase. Effect of the MHETase-PETase chimeric protein and PETase expressed on the surface of yeast cells on PET degradation is also shown.
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Affiliation(s)
- Writtik Maity
- Indian Academy Degree College-Autonomous, Bangalore, Karnataka, 560043, India
| | - Subhasish Maity
- Indian Academy Degree College-Autonomous, Bangalore, Karnataka, 560043, India
| | - Soumen Bera
- School of Life Sciences, B.S. Abdur Rahman Crescent Institute of Science and Technology, Chennai, Tamil Nadu, 600048, India
| | - Amrita Roy
- Indian Academy Degree College-Autonomous, Bangalore, Karnataka, 560043, India.
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Shi L, Liu H, Gao S, Weng Y, Zhu L. Enhanced Extracellular Production of IsPETase in Escherichia coli via Engineering of the pelB Signal Peptide. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2021; 69:2245-2252. [PMID: 33576230 DOI: 10.1021/acs.jafc.0c07469] [Citation(s) in RCA: 45] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
Poly(ethylene terephthalate) (PET) is one of the most commonly used plastics worldwide and its accumulation in the environment is a global problem. PETase from Ideonella sakaiensis 201-F6 was reported to exhibit higher hydrolytic activity and specificity for PET than other enzymes at ambient temperature. Enzymatic degradation of PET using PETase provides an attractive approach for plastic degradation and recycling. In this work, extracellular PETase was achieved by Escherichia coli BL21 using a Sec-dependent translocation signal peptide, pelB, for secretion. Furthermore, engineering of the pelB through random mutagenesis and screening was performed to improve the secretion efficiency of PETase. Evolved pelB enabled higher PETase secretion by up to 1.7-fold. The improved secretion of PETase led to more efficient hydrolysis of the PET model compound, bis (2-hydroxyethyl) terephthalic acid (BHET), PET powder, and PET film. Our study presents the first example of the increasing secretion of PETase by an engineered signal peptide, providing a promising approach to obtain extracellular PETase for efficient enzymatic degradation of PET.
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Affiliation(s)
- Lixia Shi
- University of Chinese Academy of Sciences, Beijing 100049, China
- Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin 300308, China
- National Technology Innovation Center of Synthetic Biology, Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin 300308, China
| | - Haifeng Liu
- Institute of Chemistry, University of Graz, Heinrichstrasse 28, Graz 8010, Austria
| | - Songfeng Gao
- University of Chinese Academy of Sciences, Beijing 100049, China
- Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin 300308, China
- National Technology Innovation Center of Synthetic Biology, Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin 300308, China
| | - Yunxuan Weng
- Beijing Key Laboratory of Quality Evaluation Technology for Hygiene and Safety of Plastics, Beijing Technology and Business University, Beijing 100048, China
| | - Leilei Zhu
- Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin 300308, China
- National Technology Innovation Center of Synthetic Biology, Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin 300308, China
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45
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Moog D, Zarzycki J, Rexer KH, Erb TJ, Maier UG. Engineering microalgae as a whole cell catalyst for PET degradation. Methods Enzymol 2021; 648:435-455. [PMID: 33579415 DOI: 10.1016/bs.mie.2020.12.023] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
Plastic pollution has become a serious issue on Earth. Although efficient industrial recycling processes exist, a significant fraction of plastic waste still ends up in nature, where it can endure for centuries. Slow mechanical and chemical decay lead to the formation of micro- and nanoplastics, which are washed from land into rivers and finally end up in the oceans. As such particles cannot be efficiently removed from the environment, biological degradation mechanisms are highly desirable. Several enzymes have been described that are capable of degrading certain plastic materials such as polyethylene terephthalate (PET). Such enzymes have a huge potential for future biotechnology applications. However, they require model systems that can be efficiently adapted to very specific conditions. Here, we present detailed instructions, how to convert the model diatom Phaeodactylum into a solar-fueled microbial cell factory for PETase expression, resulting in a whole cell catalyst for PET degradation at moderate temperatures under saltwater conditions.
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Affiliation(s)
- Daniel Moog
- Laboratory for Cell Biology, University of Marburg, Marburg, Germany; SYNMIKRO Research Center, Marburg, Germany.
| | - Jan Zarzycki
- Max Planck Institute for Terrestrial Microbiology, Marburg, Germany
| | - Karl-Heinz Rexer
- Department for Evolutionary Ecology of Plants, University of Marburg, Marburg, Germany
| | - Tobias J Erb
- SYNMIKRO Research Center, Marburg, Germany; Max Planck Institute for Terrestrial Microbiology, Marburg, Germany
| | - Uwe G Maier
- Laboratory for Cell Biology, University of Marburg, Marburg, Germany; SYNMIKRO Research Center, Marburg, Germany
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46
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Xi X, Ni K, Hao H, Shang Y, Zhao B, Qian Z. Secretory expression in Bacillus subtilis and biochemical characterization of a highly thermostable polyethylene terephthalate hydrolase from bacterium HR29. Enzyme Microb Technol 2020; 143:109715. [PMID: 33375975 DOI: 10.1016/j.enzmictec.2020.109715] [Citation(s) in RCA: 50] [Impact Index Per Article: 12.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2020] [Revised: 11/09/2020] [Accepted: 11/17/2020] [Indexed: 02/07/2023]
Abstract
The environmental threat posed by disposal of plastic wastes has drawn extensive attention in recent years wherein polyethylene terephthalate (PET) constitutes one of the major plastic materials in the wastes. Recycling of PET wastes into reusable materials effectively overcomes its accumulation in the environment and can be achieved by mechanical, chemical, and biological processes. In comparison to the other methods, enzymatic treatment utilizing PET hydrolyzing enzymes (PETases) is environmental-friendly which avoids the use of hazardous chemicals. In this study, we report on the secretory expression in Bacillus subtilis a PETase (BhrPETase) from the bacterium HR29, a close homologue of the leaf-branch compost cutinase (LCC) with 94 % sequence identity. The expression titer of BhrPETase reached 0.66 g/L in an engineered chaperone-overexpression Bacillus subtilis strain, and the biochemical characterization of BhrPETase for the first time revealed its high hydrolyzing activity towards amorphous PET in comparison to two reported PET hydrolyzing enzymes LCC and IsPETase, which were expressed under the same expression conditions in Bacillus subtilis in our study. Most intriguingly, purified BhrPETase displayed a melting temperature as high as 101 °C. To our knowledge it is the most thermostable bacterial PETase characterized so far. The superior activity and thermostability of BhrPETase rendered it one of the most promising PETases for plastic waste recycling and bioremediation applications in the future.
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Affiliation(s)
- Xingxiang Xi
- School of Pharmacy, Shanghai Jiao Tong University, Shanghai, 200240, China; China Research Center, DuPont Nutrition & Biosciences, Shanghai, 200335, China
| | - Kefeng Ni
- China Research Center, DuPont Nutrition & Biosciences, Shanghai, 200335, China
| | - Helong Hao
- China Research Center, DuPont Nutrition & Biosciences, Shanghai, 200335, China
| | - Yuepeng Shang
- China Research Center, DuPont Nutrition & Biosciences, Shanghai, 200335, China
| | - Bo Zhao
- School of Pharmacy, Shanghai Jiao Tong University, Shanghai, 200240, China
| | - Zhen Qian
- China Research Center, DuPont Nutrition & Biosciences, Shanghai, 200335, China.
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47
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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: 59] [Impact Index Per Article: 14.8] [Reference Citation Analysis] [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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48
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Wallace NE, Adams MC, Chafin AC, Jones DD, Tsui CL, Gruber TD. The highly crystalline PET found in plastic water bottles does not support the growth of the PETase-producing bacterium Ideonella sakaiensis. ENVIRONMENTAL MICROBIOLOGY REPORTS 2020; 12:578-582. [PMID: 32783383 DOI: 10.1111/1758-2229.12878] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/13/2020] [Revised: 07/31/2020] [Accepted: 08/09/2020] [Indexed: 06/11/2023]
Abstract
Ideonella sakaiensis produces an enzyme, PETase, that is capable of hydrolyzing polyethylene terephthalate (PET) plastic. We demonstrate that although I. sakaiensis can grow on amorphous plastic, it does not grow on highly crystalline plastic under otherwise identical conditions. Both amorphous film and amorphous plastic obtained from commercial food containers support the growth of the bacteria, whereas highly crystalline film and the highly crystalline body of a plastic water bottle do not support growth. Highly crystalline PET can be melted and rapidly cooled to make amorphous plastic which then supports bacterial growth, whereas the same plastic can be melted and slowly cooled to make crystalline plastic which does not support growth. We further subject a plastic water bottle to a top-to-bottom analysis, finding that only amorphous sections are degraded, namely the finish (threading), the topmost portion of the shoulder which connects to the finish, and the area immediately surrounding the centre of the base. Finally, we use these results to estimate that the percentage of non-degradable plastic in plastic water bottles ranges from 52% to 82% (depending on size), demonstrating that most of the plastic found in PET water bottles will not be degraded by I. sakaiensis.
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Affiliation(s)
- Noah E Wallace
- Department of Molecular Biology and Chemistry, Christopher Newport University, Newport News, VA, USA
| | - Mary C Adams
- Department of Molecular Biology and Chemistry, Christopher Newport University, Newport News, VA, USA
| | - Andrew C Chafin
- Department of Molecular Biology and Chemistry, Christopher Newport University, Newport News, VA, USA
| | - Diamonte D Jones
- Department of Molecular Biology and Chemistry, Christopher Newport University, Newport News, VA, USA
| | - Caroline L Tsui
- Department of Molecular Biology and Chemistry, Christopher Newport University, Newport News, VA, USA
| | - Todd D Gruber
- Department of Molecular Biology and Chemistry, Christopher Newport University, Newport News, VA, USA
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49
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Chia WY, Ying Tang DY, Khoo KS, Kay Lup AN, Chew KW. Nature's fight against plastic pollution: Algae for plastic biodegradation and bioplastics production. ENVIRONMENTAL SCIENCE AND ECOTECHNOLOGY 2020; 4:100065. [PMID: 36157709 PMCID: PMC9488055 DOI: 10.1016/j.ese.2020.100065] [Citation(s) in RCA: 83] [Impact Index Per Article: 20.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/08/2020] [Revised: 10/30/2020] [Accepted: 10/31/2020] [Indexed: 05/11/2023]
Abstract
The increased global demand for plastic materials has led to severe plastic waste pollution, particularly to the marine environment. This critical issue affects both sea life and human beings since microplastics can enter the food chain and cause several health impacts. Plastic recycling, chemical treatments, incineration and landfill are apparently not the optimum solutions for reducing plastic pollution. Hence, this review presents two newly identified environmentally friendly approaches, plastic biodegradation and bioplastic production using algae, to solve the increased global plastic waste. Algae, particularly microalgae, can degrade the plastic materials through the toxins systems or enzymes synthesized by microalgae itself while using the plastic polymers as carbon sources. Utilizing algae for plastic biodegradation has been critically reviewed in this paper to demonstrate the mechanism and how microplastics affect the algae. On the other hand, algae-derived bioplastics have identical properties and characteristics as petroleum-based plastics, while remarkably being biodegradable in nature. This review provides new insights into different methods of producing algae-based bioplastics (e.g., blending with other materials and genetic engineering), followed by the discussion on the challenges and further research direction to increase their commercial feasibility.
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Affiliation(s)
- Wen Yi Chia
- School of Energy and Chemical Engineering, Xiamen University Malaysia, Selangor Darul Ehsan, 43900, Malaysia
- College of Chemistry and Chemical Engineering, Xiamen University, Xiamen, 361005, Fujian, China
| | - Doris Ying Ying Tang
- Department of Chemical and Environmental Engineering, Faculty of Science and Engineering, University of Nottingham Malaysia, Jalan Broga, 43500, Semenyih, Selangor Darul Ehsan, Malaysia
| | - Kuan Shiong Khoo
- Department of Chemical and Environmental Engineering, Faculty of Science and Engineering, University of Nottingham Malaysia, Jalan Broga, 43500, Semenyih, Selangor Darul Ehsan, Malaysia
| | - Andrew Ng Kay Lup
- School of Energy and Chemical Engineering, Xiamen University Malaysia, Selangor Darul Ehsan, 43900, Malaysia
- College of Chemistry and Chemical Engineering, Xiamen University, Xiamen, 361005, Fujian, China
| | - Kit Wayne Chew
- School of Energy and Chemical Engineering, Xiamen University Malaysia, Selangor Darul Ehsan, 43900, Malaysia
- College of Chemistry and Chemical Engineering, Xiamen University, Xiamen, 361005, Fujian, China
- Corresponding author. School of Energy and Chemical Engineering, Xiamen University Malaysia, Selangor Darul Ehsan, 43900, Malaysia.
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50
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Purohit J, Chattopadhyay A, Teli B. Metagenomic Exploration of Plastic Degrading Microbes for Biotechnological Application. Curr Genomics 2020; 21:253-270. [PMID: 33071619 PMCID: PMC7521044 DOI: 10.2174/1389202921999200525155711] [Citation(s) in RCA: 30] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2020] [Revised: 04/14/2020] [Accepted: 04/21/2020] [Indexed: 01/08/2023] Open
Abstract
Since the last few decades, the promiscuous and uncontrolled use of plastics led to the accumulation of millions of tons of plastic waste in the terrestrial and marine environment. It elevated the risk of environmental pollution and climate change. The concern arises more due to the reckless and unscientific disposal of plastics containing high molecular weight polymers, viz., polystyrene, polyamide, polyvinylchloride, polypropylene, polyurethane, and polyethylene, etc. which are very difficult to degrade. Thus, the focus is now paid to search for efficient, eco-friendly, low-cost waste management technology. Of them, degradation of non-degradable synthetic polymer using diverse microbial agents, viz., bacteria, fungi, and other extremophiles become an emerging option. So far, very few microbial agents and their secreted enzymes have been identified and characterized for plastic degradation, but with low efficiency. It might be due to the predominance of uncultured microbial species, which consequently remain unexplored from the respective plastic degrading milieu. To overcome this problem, metagenomic analysis of microbial population engaged in the plastic biodegradation is advisable to decipher the microbial community structure and to predict their biodegradation potential in situ. Advancements in sequencing technologies and bioinformatics analysis allow the rapid metagenome screening that helps in the identification of total microbial community and also opens up the scope for mining genes or enzymes (hydrolases, laccase, etc.) engaged in polymer degradation. Further, the extraction of the core microbial population and their adaptation, fitness, and survivability can also be deciphered through comparative metagenomic study. It will help to engineer the microbial community and their metabolic activity to speed up the degradation process.
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Affiliation(s)
- Jyotika Purohit
- 1Department of Plant Pathology, C.P. College of Agriculture, S.D. Agricultural University, SK Nagar, (Guj.), India; 2Division of Plant Pathology, IARI, New Delhi, India; 3Department of Mycology & Plant Pathology, Institute of Agricultural Sciences, Banaras Hindu University, Varanasi, (U.P.), India
| | - Anirudha Chattopadhyay
- 1Department of Plant Pathology, C.P. College of Agriculture, S.D. Agricultural University, SK Nagar, (Guj.), India; 2Division of Plant Pathology, IARI, New Delhi, India; 3Department of Mycology & Plant Pathology, Institute of Agricultural Sciences, Banaras Hindu University, Varanasi, (U.P.), India
| | - Basavaraj Teli
- 1Department of Plant Pathology, C.P. College of Agriculture, S.D. Agricultural University, SK Nagar, (Guj.), India; 2Division of Plant Pathology, IARI, New Delhi, India; 3Department of Mycology & Plant Pathology, Institute of Agricultural Sciences, Banaras Hindu University, Varanasi, (U.P.), India
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