1
|
He L, Yang SS, Ding J, Chen CX, Yang F, He ZL, Pang JW, Peng BY, Zhang Y, Xing DF, Ren NQ, Wu WM. Biodegradation of polyethylene terephthalate by Tenebrio molitor: Insights for polymer chain size, gut metabolome and host genes. JOURNAL OF HAZARDOUS MATERIALS 2024; 465:133446. [PMID: 38219578 DOI: 10.1016/j.jhazmat.2024.133446] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/18/2023] [Revised: 01/02/2024] [Accepted: 01/03/2024] [Indexed: 01/16/2024]
Abstract
Polyethylene terephthalate (PET or polyester) is a commonly used plastic and also contributes to the majority of plastic wastes. Mealworms (Tenebrio molitor larvae) are capable of biodegrading major plastic polymers but their degrading ability for PET has not been characterized based on polymer chain size molecular size, gut microbiome, metabolome and transcriptome. We verified biodegradation of commercial PET by T. molitor larvae in a previous report. Here, we reported that biodegradation of commercial PET (Mw 29.43 kDa) was further confirmed by using the δ13C signature as an indication of bioreaction, which was increased from - 27.50‰ to - 26.05‰. Under antibiotic suppression of gut microbes, the PET was still depolymerized, indicating that the host digestive enzymes could degrade PET independently. Biodegradation of high purity PET with low, medium, and high molecular weights (MW), i.e., Mw values of 1.10, 27.10, and 63.50 kDa with crystallinity 53.66%, 33.43%, and 4.25%, respectively, showed a mass reduction of > 95%, 86%, and 74% via broad depolymerization. Microbiome analyses indicated that PET diets shifted gut microbiota to three distinct structures, depending on the low, medium, and high MW. Metagenome sequencing, transcriptomic, and metabolic analyses indicated symbiotic biodegradation of PET by the host and gut microbiota. After PET was fed, the host's genes encoding degradation enzymes were upregulated, including genes encoding oxidizing, hydrolyzing, and non-specific CYP450 enzymes. Gut bacterial genes for biodegrading intermediates and nitrogen fixation also upregulated. The multiple-functional metabolic pathways for PET biodegradation ensured rapid biodegradation resulting in a half-life of PET less than 4 h with less negative impact by PET MW and crystallinity.
Collapse
Affiliation(s)
- Lei He
- CAS Key Laboratory of Urban Pollutant Conversion, Department of Environmental Science and Engineering, University of Science and Technology of China, Hefei 230026, China; State Key Laboratory of Urban Water Resource and Environment, School of Environment, Harbin Institute of Technology, Harbin 150090, China
| | - Shan-Shan Yang
- State Key Laboratory of Urban Water Resource and Environment, School of Environment, Harbin Institute of Technology, Harbin 150090, China.
| | - Jie Ding
- State Key Laboratory of Urban Water Resource and Environment, School of Environment, Harbin Institute of Technology, Harbin 150090, China
| | - Cheng-Xin Chen
- State Key Laboratory of Urban Water Resource and Environment, School of Environment, Harbin Institute of Technology, Harbin 150090, China
| | - Fan Yang
- School of Life Science and Technology, Harbin Institute of Technology, Harbin 150090, China
| | - Zhi-Li He
- Southern Marine Science and Engineering Guangdong Laboratory (Zhuhai), Zhuhai 519080, China
| | - Ji-Wei Pang
- China Energy Conservation and Environmental Protection Group, Beijing 100089, China
| | - Bo-Yu Peng
- State Key Laboratory of Pollution Control and Resource Reuse, College of Environmental Science and Engineering, Tongji University, Shanghai 200092, China
| | - Yalei Zhang
- State Key Laboratory of Pollution Control and Resource Reuse, College of Environmental Science and Engineering, Tongji University, Shanghai 200092, China
| | - De-Feng Xing
- State Key Laboratory of Urban Water Resource and Environment, School of Environment, Harbin Institute of Technology, Harbin 150090, China
| | - Nan-Qi Ren
- State Key Laboratory of Urban Water Resource and Environment, School of Environment, Harbin Institute of Technology, Harbin 150090, China
| | - Wei-Min Wu
- Department of Civil and Environmental Engineering, William & Cloy Codiga Resource Recovery Center, Stanford University, Stanford, CA 94305, USA.
| |
Collapse
|
2
|
Mishra R, Chavda P, Kumar R, Pandit R, Joshi M, Kumar M, Joshi C. Exploring genetic landscape of low-density polyethylene degradation for sustainable troubleshooting of plastic pollution at landfills. THE SCIENCE OF THE TOTAL ENVIRONMENT 2024; 912:168882. [PMID: 38040372 DOI: 10.1016/j.scitotenv.2023.168882] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/01/2023] [Revised: 11/04/2023] [Accepted: 11/23/2023] [Indexed: 12/03/2023]
Abstract
Plastic pollution increases globally due to the high volume of its production and inadequate mismanagement, leading to dumps in landfills affecting terrestrial and aquatic ecosystems. Landfills, as sink for plastics, leach various toxic chemicals and microplastics into the environment. We scrutinized the genetic expression for low-density polyethylene (LDPE) degradation via microorganisms to investigate cell viability and metabolic activities for biodegradation and genetic profiling. Samples were collected from the Pirana waste landfill at Ahmedabad, Gujarat, which is one of the largest and oldest municipal solid waste (MSW) dump sites in Asia. Results analyzed that isolated bacterial culture PN(A)1 (Bacillus cereus) is metabolically active on LDPE as carbon source during starvation conditions when incubated for up to 60 days, which was confirmed via 2,3,5-triphenyl-tetrazolium chloride (TTC) reduction test, reported cell viability and LDPE degradation. Abrasions, surface erosions, and cavity formations were analyzed via scanning electron microscopy (SEM), whereas the breakdown of high molecular polymers converted to low molecules, i.e., depolymerization, was also observed via Fourier-transform infrared (FTIR) spectroscopy over 90 days, along with changes in functional groups of carboxylic acids and aldehyde as well as the formation of polysulfide, aliphatic compounds, aromatic ethers, alcohols, and ether linkages. Further, transcriptomic analysis was performed via DESeq2 analysis to understand key gene expression patterns and pathways involved in LDPE degradation. During the initial phase of LDPE degradation, genes related to biological processes, like membrane transportation, ABC transporters, carbon and lipid metabolism, fatty acid degradation/oxidation, and TCA cycle, are likely to indicate pathways for stress response and molecular functions, like oxidoreductase, catalytic, lyase, transferase, and hydrolase activities were expressed. Interlinking between metabolic pathways indicates biodegradation process that mineralizes LDPE during subsequent incubation days. These pathways can be targeted for increasing the efficiency of LDPE degradation using microbes in future studies. Thus, considering microbial-mediated biodegradation as practical, eco-friendly, and low-cost alternatives, healthy biomes can degrade polymers in natural environments explored by understanding the genetic and enzymatic expression, connecting their role in the process to the likely metabolic pathways involved, thereby increasing the rate of their biodegradation.
Collapse
Affiliation(s)
- Roshani Mishra
- Gujarat Biotechnology Research Centre (GBRC), Gandhinagar, Gujarat 382011, India
| | - Priyank Chavda
- Gujarat Biotechnology Research Centre (GBRC), Gandhinagar, Gujarat 382011, India
| | - Rakesh Kumar
- Department of Biosystems Engineering, Auburn University, Auburn, AL 36849, USA
| | - Ramesh Pandit
- Gujarat Biotechnology Research Centre (GBRC), Gandhinagar, Gujarat 382011, India
| | - Madhvi Joshi
- Gujarat Biotechnology Research Centre (GBRC), Gandhinagar, Gujarat 382011, India
| | - Manish Kumar
- Sustainability Cluster, School of Advanced Engineering, UPES, Dehradun, Uttarakhand 248007, India; Escuela de Ingeniería y Ciencias, Tecnologico de Monterrey, Campus Monterrey, Eugenio Garza Sada 2501 Sur, Monterrey 64849, Mexico.
| | - Chaitanya Joshi
- Gujarat Biotechnology Research Centre (GBRC), Gandhinagar, Gujarat 382011, India.
| |
Collapse
|
3
|
Lv S, Li Y, Zhao S, Shao Z. Biodegradation of Typical Plastics: From Microbial Diversity to Metabolic Mechanisms. Int J Mol Sci 2024; 25:593. [PMID: 38203764 PMCID: PMC10778777 DOI: 10.3390/ijms25010593] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2023] [Revised: 12/22/2023] [Accepted: 12/27/2023] [Indexed: 01/12/2024] Open
Abstract
Plastic production has increased dramatically, leading to accumulated plastic waste in the ocean. Marine plastics can be broken down into microplastics (<5 mm) by sunlight, machinery, and pressure. The accumulation of microplastics in organisms and the release of plastic additives can adversely affect the health of marine organisms. Biodegradation is one way to address plastic pollution in an environmentally friendly manner. Marine microorganisms can be more adapted to fluctuating environmental conditions such as salinity, temperature, pH, and pressure compared with terrestrial microorganisms, providing new opportunities to address plastic pollution. Pseudomonadota (Proteobacteria), Bacteroidota (Bacteroidetes), Bacillota (Firmicutes), and Cyanobacteria were frequently found on plastic biofilms and may degrade plastics. Currently, diverse plastic-degrading bacteria are being isolated from marine environments such as offshore and deep oceanic waters, especially Pseudomonas spp. Bacillus spp. Alcanivoras spp. and Actinomycetes. Some marine fungi and algae have also been revealed as plastic degraders. In this review, we focused on the advances in plastic biodegradation by marine microorganisms and their enzymes (esterase, cutinase, laccase, etc.) involved in the process of biodegradation of polyethylene terephthalate (PET), polystyrene (PS), polyethylene (PE), polyvinyl chloride (PVC), and polypropylene (PP) and highlighted the need to study plastic biodegradation in the deep sea.
Collapse
Affiliation(s)
- Shiwei Lv
- Key Laboratory of Marine Genetic Resources, Third Institute of Oceanography, Ministry of Natural Resources of China, Xiamen 361005, China; (S.L.); (Y.L.); (S.Z.)
- School of Environmental Science, Harbin Institute of Technology, Harbin 150090, China
| | - Yufei Li
- Key Laboratory of Marine Genetic Resources, Third Institute of Oceanography, Ministry of Natural Resources of China, Xiamen 361005, China; (S.L.); (Y.L.); (S.Z.)
- School of Marine Sciences, China University of Geosciences, Beijing 100083, China
| | - Sufang Zhao
- Key Laboratory of Marine Genetic Resources, Third Institute of Oceanography, Ministry of Natural Resources of China, Xiamen 361005, China; (S.L.); (Y.L.); (S.Z.)
| | - Zongze Shao
- Key Laboratory of Marine Genetic Resources, Third Institute of Oceanography, Ministry of Natural Resources of China, Xiamen 361005, China; (S.L.); (Y.L.); (S.Z.)
- School of Environmental Science, Harbin Institute of Technology, Harbin 150090, China
- School of Marine Sciences, China University of Geosciences, Beijing 100083, China
- Southern Marine Science and Engineering Guangdong Laboratory (Zhuhai), Zhuhai 519000, China
| |
Collapse
|
4
|
He Y, Deng X, Jiang L, Hao L, Shi Y, Lyu M, Zhang L, Wang S. Current advances, challenges and strategies for enhancing the biodegradation of plastic waste. THE SCIENCE OF THE TOTAL ENVIRONMENT 2024; 906:167850. [PMID: 37844647 DOI: 10.1016/j.scitotenv.2023.167850] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/18/2023] [Revised: 10/13/2023] [Accepted: 10/13/2023] [Indexed: 10/18/2023]
Abstract
Due to its highly recalcitrant nature, the growing accumulation of plastic waste is becoming an urgent global problem. Biodegradation is one of the best possible approaches for the treatment of plastic waste in an environmentally friendly manner, but our current knowledge on the underlying mechanisms, as well as strategies for the development and enhancement of plastic biodegradation are still limited. This review aims to provide an updated and comprehensive overview of current research on plastic waste biodegradation, focusing on enhancement strategies with ongoing research significance, including the mining of highly efficient plastic-degrading microorganisms/enzymes, utilization of synergistic additives, novel pretreatment approaches, modification via molecular engineering, and construction of bacterial/enzyme consortia systems. Studying these strategies can (i) enrich the high-performance microbial/enzymes toolbox for plastic degradation, (ii) provide methods for recycling and upgrading plastics, as well as (iii) enable further molecular modification and functional optimization of plastic-degrading enzymes to realize economically viable biodegradation of plastics. To the best of our knowledge, this is the first review to discuss in detail strategies to enhance biodegradation of plastics. Finally, some recommendations for future research on plastic biodegradation are listed, hoping to provide the best direction for tackling the plastic waste dilemma in the future.
Collapse
Affiliation(s)
- Yuehui He
- Jiangsu Key Laboratory of Marine Bioresources and Environment/Jiangsu Key Laboratory of Marine, Biotechnology, Jiangsu Ocean University, Lianyungang 222005, China; Co-Innovation Center of Jiangsu Marine Bio-Industry Technology, Jiangsu Ocean University, Lianyungang 222005, China; College of Marine Food and Bioengineering, Jiangsu Ocean University, Lianyungang 222005, China
| | - Xilong Deng
- College of Marine Food and Bioengineering, Jiangsu Ocean University, Lianyungang 222005, China
| | - Lei Jiang
- College of Marine Food and Bioengineering, Jiangsu Ocean University, Lianyungang 222005, China
| | - Lijuan Hao
- College of Marine Food and Bioengineering, Jiangsu Ocean University, Lianyungang 222005, China
| | - Yong Shi
- College of Marine Food and Bioengineering, Jiangsu Ocean University, Lianyungang 222005, China
| | - Mingsheng Lyu
- Jiangsu Key Laboratory of Marine Bioresources and Environment/Jiangsu Key Laboratory of Marine, Biotechnology, Jiangsu Ocean University, Lianyungang 222005, China; Co-Innovation Center of Jiangsu Marine Bio-Industry Technology, Jiangsu Ocean University, Lianyungang 222005, China; College of Marine Food and Bioengineering, Jiangsu Ocean University, Lianyungang 222005, China
| | - Lei Zhang
- Jiangsu Key Laboratory of Marine Bioresources and Environment/Jiangsu Key Laboratory of Marine, Biotechnology, Jiangsu Ocean University, Lianyungang 222005, China; Co-Innovation Center of Jiangsu Marine Bio-Industry Technology, Jiangsu Ocean University, Lianyungang 222005, China; College of Marine Food and Bioengineering, Jiangsu Ocean University, Lianyungang 222005, China.
| | - Shujun Wang
- Jiangsu Key Laboratory of Marine Bioresources and Environment/Jiangsu Key Laboratory of Marine, Biotechnology, Jiangsu Ocean University, Lianyungang 222005, China; Co-Innovation Center of Jiangsu Marine Bio-Industry Technology, Jiangsu Ocean University, Lianyungang 222005, China; College of Marine Food and Bioengineering, Jiangsu Ocean University, Lianyungang 222005, China.
| |
Collapse
|
5
|
Kim JH, Lee SH, Lee BM, Son KH, Park HY. Biodegradation Potential of Polyethylene Terephthalate by the Two Insect Gut Symbionts Xanthomonas sp. HY-74 and Bacillus sp. HY-75. Polymers (Basel) 2023; 15:3546. [PMID: 37688172 PMCID: PMC10489954 DOI: 10.3390/polym15173546] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2023] [Revised: 08/17/2023] [Accepted: 08/23/2023] [Indexed: 09/10/2023] Open
Abstract
Polyethylene terephthalate (PET) is a plastic material that is widely used in beverage bottles, food packaging, and other consumer products, which is highly resistant to biodegradation. In this study, we investigated the effects of two insect gut symbionts, Xanthomonas sp. HY-74 and Bacillus sp. HY-75, during PET biodegradation. Both strains degraded PET-containing agar plates, and the sole nutrition source assay showed that HY-74 had different degradation rates depending on the presence of specific carbon and nitrogen sources, whereas HY-75 exhibited comparable degradation across all tested conditions. The two strains biodegraded the PET film with 1.57 ± 0.21% and 1.42 ± 0.46% weight loss after 6 weeks, respectively. Changes in the morphology and structure of the PET films, such as erosion, scratching, and surface roughening, were determined using scanning electron microscopy (SEM). Further, the two strains biodegraded PET powder, broke it into its degradation products, and changed the surface functional groups. This is the first study to investigate the biodegradation of PET by Hymenoptera gut-derived microbes and offers promising insights into the potential applications of insect gut symbionts in PET waste management.
Collapse
Affiliation(s)
| | | | | | | | - Ho-Yong Park
- Microbiome Convergence Research Center, Korea Research Institute of Bioscience and Biotechnology, Daejeon 34141, Republic of Korea; (J.-H.K.); (S.-H.L.); (B.-M.L.); (K.-H.S.)
| |
Collapse
|
6
|
Klose L, Meyer-Heydecke N, Wongwattanarat S, Chow J, Pérez García P, Carré C, Streit W, Antranikian G, Romero AM, Liese A. Towards Sustainable Recycling of Epoxy-Based Polymers: Approaches and Challenges of Epoxy Biodegradation. Polymers (Basel) 2023; 15:2653. [PMID: 37376299 PMCID: PMC10305103 DOI: 10.3390/polym15122653] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2023] [Accepted: 06/08/2023] [Indexed: 06/29/2023] Open
Abstract
Epoxy resins are highly valued for their remarkable mechanical and chemical properties and are extensively used in various applications such as coatings, adhesives, and fiber-reinforced composites in lightweight construction. Composites are especially important for the development and implementation of sustainable technologies such as wind power, energy-efficient aircrafts, and electric cars. Despite their advantages, their non-biodegradability raises challenges for the recycling of polymer and composites in particular. Conventional methods employed for epoxy recycling are characterized by their high energy consumption and the utilization of toxic chemicals, rendering them rather unsustainable. Recent progress has been made in the field of plastic biodegradation, which is considered more sustainable than energy-intensive mechanical or thermal recycling methods. However, the current successful approaches in plastic biodegradation are predominantly focused on polyester-based polymers, leaving more recalcitrant plastics underrepresented in this area of research. Epoxy polymers, characterized by their strong cross-linking and predominantly ether-based backbone, exhibit a highly rigid and durable structure, placing them within this category. Therefore, the objective of this review paper is to examine the various approaches that have been employed for the biodegradation of epoxy so far. Additionally, the paper sheds light on the analytical techniques utilized in the development of these recycling methods. Moreover, the review addresses the challenges and opportunities entailed in epoxy recycling through bio-based approaches.
Collapse
Affiliation(s)
- Leon Klose
- Institute of Technical Biocatalysis, Hamburg University of Technology, 21073 Hamburg, Germany
| | - Neele Meyer-Heydecke
- Institute of Technical Biocatalysis, Hamburg University of Technology, 21073 Hamburg, Germany
| | - Sasipa Wongwattanarat
- Department of Microbiology and Biotechnology, University of Hamburg, 22609 Hamburg, Germany
| | - Jennifer Chow
- Department of Microbiology and Biotechnology, University of Hamburg, 22609 Hamburg, Germany
| | - Pablo Pérez García
- Department of Microbiology and Biotechnology, University of Hamburg, 22609 Hamburg, Germany
| | - Camille Carré
- Airbus Defence and Space GmbH, Central Research and Technology, 81663 Munich, Germany
| | - Wolfgang Streit
- Department of Microbiology and Biotechnology, University of Hamburg, 22609 Hamburg, Germany
| | - Garabed Antranikian
- Institute of Technical Biocatalysis, Hamburg University of Technology, 21073 Hamburg, Germany
| | - Ana Malvis Romero
- Institute of Technical Biocatalysis, Hamburg University of Technology, 21073 Hamburg, Germany
| | - Andreas Liese
- Institute of Technical Biocatalysis, Hamburg University of Technology, 21073 Hamburg, Germany
| |
Collapse
|
7
|
Barhoumi B, Metian M, Oberhaensli F, Mourgkogiannis N, Karapanagioti HK, Bersuder P, Tolosa I. Extruded polystyrene microplastics as a source of brominated flame retardant additives in the marine environment: long-term field and laboratory experiments. ENVIRONMENT INTERNATIONAL 2023; 172:107797. [PMID: 36773563 DOI: 10.1016/j.envint.2023.107797] [Citation(s) in RCA: 8] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/02/2022] [Revised: 01/30/2023] [Accepted: 02/01/2023] [Indexed: 06/18/2023]
Abstract
Microplastics (MPs) in the environment have become a global concern, not only for the physical effects of the plastic particles themselves but also for being vectors of chemical additives. In this context, little is known about the ability of MPs, particularly extruded polystyrene microplastics (XPS-MPs), to release organic chemical additives in the marine environment. In this study, a series of field and laboratory experiments were carried out to determine the leaching behaviour of organic additives including brominated flame retardants from XPS-MPs into seawater. The conducted experiments confirmed a rapid release of bisphenol A (BPA), 2,4,6-tribromophenol (TBP), tetrabromobisphenol A (TBBPA) and hexabromocyclododecane diastereoisomers (α-, β-, and γ-HBCDD) from the studied MPs followed by a slower rate of release over time. The effects of environmental factors on the leaching rates of these additives were also examined. Increasing Dissolved Organic Matter (DOM) concentrations and the temperature of the seawater enhanced the release of additives by increasing their solubility and polymer flexibility. In contrast, pH tested at 7, 7.5 and 8 was found to have a minor effect on additives leaching; and salinity negatively affected the leaching rate likely due to their reduced solubility and reduced diffusion from the MPs. The present study provides empirical evidence of the behaviour of XPS-MPs as a source of organic additives in the marine environment that merit further investigation.
Collapse
Affiliation(s)
- Badreddine Barhoumi
- IAEA Marine Environment Laboratories, 4a Quai Antoine 1er, 98000 Monaco, Principality of Monaco.
| | - Marc Metian
- IAEA Marine Environment Laboratories, 4a Quai Antoine 1er, 98000 Monaco, Principality of Monaco
| | - François Oberhaensli
- IAEA Marine Environment Laboratories, 4a Quai Antoine 1er, 98000 Monaco, Principality of Monaco
| | | | | | - Philippe Bersuder
- IAEA Marine Environment Laboratories, 4a Quai Antoine 1er, 98000 Monaco, Principality of Monaco
| | - Imma Tolosa
- IAEA Marine Environment Laboratories, 4a Quai Antoine 1er, 98000 Monaco, Principality of Monaco.
| |
Collapse
|
8
|
Edwards S, León-Zayas R, Ditter R, Laster H, Sheehan G, Anderson O, Beattie T, Mellies JL. Microbial Consortia and Mixed Plastic Waste: Pangenomic Analysis Reveals Potential for Degradation of Multiple Plastic Types via Previously Identified PET Degrading Bacteria. Int J Mol Sci 2022; 23:5612. [PMID: 35628419 PMCID: PMC9146961 DOI: 10.3390/ijms23105612] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2022] [Revised: 05/11/2022] [Accepted: 05/13/2022] [Indexed: 02/01/2023] Open
Abstract
The global utilization of single-use, non-biodegradable plastics, such as bottles made of polyethylene terephthalate (PET), has contributed to catastrophic levels of plastic pollution. Fortunately, microbial communities are adapting to assimilate plastic waste. Previously, our work showed a full consortium of five bacteria capable of synergistically degrading PET. Using omics approaches, we identified the key genes implicated in PET degradation within the consortium's pangenome and transcriptome. This analysis led to the discovery of a novel PETase, EstB, which has been observed to hydrolyze the oligomer BHET and the polymer PET. Besides the genes implicated in PET degradation, many other biodegradation genes were discovered. Over 200 plastic and plasticizer degradation-related genes were discovered through the Plastic Microbial Biodegradation Database (PMBD). Diverse carbon source utilization was observed by a microbial community-based assay, which, paired with an abundant number of plastic- and plasticizer-degrading enzymes, indicates a promising possibility for mixed plastic degradation. Using RNAseq differential analysis, several genes were predicted to be involved in PET degradation, including aldehyde dehydrogenases and several classes of hydrolases. Active transcription of PET monomer metabolism was also observed, including the generation of polyhydroxyalkanoate (PHA)/polyhydroxybutyrate (PHB) biopolymers. These results present an exciting opportunity for the bio-recycling of mixed plastic waste with upcycling potential.
Collapse
Affiliation(s)
- Sabrina Edwards
- Biology Department, Reed College, Portland, OR 97202, USA; (S.E.); (R.D.); (H.L.); (T.B.)
| | - Rosa León-Zayas
- Biology Department, Willamette University, Salem, OR 97301, USA; (R.L.-Z.); (G.S.); (O.A.)
| | - Riyaz Ditter
- Biology Department, Reed College, Portland, OR 97202, USA; (S.E.); (R.D.); (H.L.); (T.B.)
| | - Helen Laster
- Biology Department, Reed College, Portland, OR 97202, USA; (S.E.); (R.D.); (H.L.); (T.B.)
| | - Grace Sheehan
- Biology Department, Willamette University, Salem, OR 97301, USA; (R.L.-Z.); (G.S.); (O.A.)
| | - Oliver Anderson
- Biology Department, Willamette University, Salem, OR 97301, USA; (R.L.-Z.); (G.S.); (O.A.)
| | - Toby Beattie
- Biology Department, Reed College, Portland, OR 97202, USA; (S.E.); (R.D.); (H.L.); (T.B.)
| | - Jay L. Mellies
- Biology Department, Reed College, Portland, OR 97202, USA; (S.E.); (R.D.); (H.L.); (T.B.)
| |
Collapse
|