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Bhanot V, Mamta, Gupta S, Panwar J. Phylloplane fungus Curvularia dactyloctenicola VJP08 effectively degrades commercially available PS product. JOURNAL OF ENVIRONMENTAL MANAGEMENT 2024; 351:119920. [PMID: 38157570 DOI: 10.1016/j.jenvman.2023.119920] [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: 10/05/2023] [Revised: 11/20/2023] [Accepted: 12/11/2023] [Indexed: 01/03/2024]
Abstract
Polystyrene (PS), a widely produced plastic with an extended carbon (C-C) backbone that resists microbial attack, is produced in enormous quantities throughout the World. Naturally occurring plasticizers such as plant cuticle and lignocelluloses share similar properties to synthetic plastics such as hydrophobicity, structural complexity, and higher recalcitrance to degradation. In due course of time, phytopathogenic fungi have evolved strategies to overcome these limitations and utilize lignocellulosic waste for their nutrition. The present investigation focuses on the utilization of phylloplane fungus, Curvularia dactyloctenicola VJP08 towards its ability to colonize and degrade commercially available PS lids. The fungus was observed to densely grow onto PS samples over an incubation period of 30 days. The morphological changes showcased extensive fungal growth with mycelial imbrication invading the PS surface for carbon extraction leading to the appearance of cracks and holes in the PS surface. It was further confirmed by EDS analysis which indicated that carbon was extracted from PS for the fungal growth. Further, 3.57% decrease in the weight, 8.8% decrease in the thickness and 2 °C decrease in the glass transition temperature (Tg) confirmed alterations in the structural integrity of PS samples by the fungal action. GC-MS/MS analysis of the treated PS samples also showed significant decrease in the concentration of benzene and associated aromatic derivatives confirming the degradation of PS samples and subsequent utilization of generated by-products by the fungus for growth. Overall, the present study confirmed the degradation and utilization of commercially available PS samples by phylloplane fungus C. dactyloctenicola VJP08. These findings establish a clear cross-assessment of the phylloplane fungi for their prospective use in the development of degradation strategies of synthetic plastics.
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Affiliation(s)
- Vishalakshi Bhanot
- Department of Biological Sciences, Birla Institute of Technology and Sciences, Pilani, 333031, Rajasthan, India
| | - Mamta
- Department of Biological Sciences, Birla Institute of Technology and Sciences, Pilani, 333031, Rajasthan, India
| | - Suresh Gupta
- Department of Chemical Engineering, Birla Institute of Technology and Science, Pilani, 333031, Rajasthan, India
| | - Jitendra Panwar
- Department of Biological Sciences, Birla Institute of Technology and Sciences, Pilani, 333031, Rajasthan, India.
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Li Z, Liu W, Rahaman MH, Chen Z, Yan J, Zhai J. Polystyrene microplastics accumulation in lab-scale vertical flow constructed wetlands: impacts and fate. JOURNAL OF HAZARDOUS MATERIALS 2024; 461:132576. [PMID: 37738848 DOI: 10.1016/j.jhazmat.2023.132576] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/21/2023] [Revised: 08/29/2023] [Accepted: 09/16/2023] [Indexed: 09/24/2023]
Abstract
Microplastics (MPs) are ubiquitous pollutants that significantly threaten organisms and ecosystems. Constructed wetlands (CWs), a nature-based treatment technology, can effectively remove MPs from wastewater. However, the responses of CWs when exposed to MPs remain unclear. In this study, lab-scale vertical flow constructed wetlands (VFCWs) were installed for receiving polystyrene (PS) MPs at concentrations of 100 μg/L and 1000 μg/L. The results showed that exposure to PS-MPs has no effects on COD and TP removal in VFCWs, but TN removal decreased by 3.69-5.37 %. Further investigation revealed that PS-MPs significantly impacted microbial communities and metabolic functions. The abundances of predominant nitrifiers (Nitrospira and Nitrosomonas) and denitrifiers (Nakamurella, Bradyrhizobium, and Bacillus) in VFCWs were significantly reduced, aligning with the responses of key enzymes. The presence of PS-MPs also decreased nitrogen removal by plant uptake, leading to decreased plant biomass and chlorophyll by 39.32-48.75 % and 5.92-32.19 %, respectively. Notably, > 90 % removal rates were observed for PS-MPs within VFCWs. In addition to PS-MPs interception by VFCWs substrate, the increase of released benzenes indicated that the PS-MPs biodegradation occurred. Such insights are vital for developing sustainable solutions to mitigate MPs' adverse effects on ecosystems.
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Affiliation(s)
- Zhenchen Li
- College of Environment and Ecology, Chongqing University, Chongqing 400045, China
| | - Wenbo Liu
- Institute for Smart City of Chongqing University in Liyang, Chongqing University, Jiangsu 213300, China
| | - Md Hasibur Rahaman
- Institute for Smart City of Chongqing University in Liyang, Chongqing University, Jiangsu 213300, China
| | - Zhongbing Chen
- Department of Applied Ecology, Faculty of Environmental Sciences, Czech University of Life Sciences Prague, Kamýcka 129, Praha-Suchdol 16500, Czech Republic
| | - Jixia Yan
- College of Environment and Ecology, Chongqing University, Chongqing 400045, China
| | - Jun Zhai
- College of Environment and Ecology, Chongqing University, Chongqing 400045, China; Institute for Smart City of Chongqing University in Liyang, Chongqing University, Jiangsu 213300, China.
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Kang MG, Kwak MJ, Kim Y. Polystyrene microplastics biodegradation by gut bacterial Enterobacter hormaechei from mealworms under anaerobic conditions: Anaerobic oxidation and depolymerization. JOURNAL OF HAZARDOUS MATERIALS 2023; 459:132045. [PMID: 37480606 DOI: 10.1016/j.jhazmat.2023.132045] [Citation(s) in RCA: 9] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/27/2023] [Revised: 07/09/2023] [Accepted: 07/10/2023] [Indexed: 07/24/2023]
Abstract
Synthetic plastic is used throughout daily life and industry, threatening organisms with microplastic pollution. Polystyrene is a major plastic polymer and also widely found sources of plastic wastes and microplastics. Here, we report that Enterobacter hormaechei LG3 (CP118279.1), a facultative anaerobic bacterial strain isolated from the gut of Tenebrio molitor larvae (mealworms) can oxidize and depolymerize polystyrene under anaerobic conditions. LG3 performed biodegradation while forming a biofilm on the plastic surface. PS biodegradation was characterized by analyses of surface oxidation, change in morphology and molecular weights, and production of biodegraded derivative. The biodegradation performance by LG3 was compared with PS biodegradation by Bacillus amyloliquefaciens SCGB1 under both anaerobic and aerobic conditions. In addition, through nanopore sequencing technology, we identified degradative enzymes, including thiol peroxidase (tpx), alkyl hydroperoxide reductase C (ahpC) and bacterioferritin comigratory protein (bcp). Along with the upregulation of degradative enzymes for biodegradation, changes in lipid A and biofilm-associated proteins were also observed after the cells were incubated with polystyrene microplastics. Our results provide evidence for anaerobic biodegradation by polystyrene-degrading bacteria and show alterations in gene expression patterns after polystyrene microplastics treatment in the opportunistic pathogen Enterobacter hormaechei.
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Affiliation(s)
- Min-Geun Kang
- Department of Agricultural Biotechnology and Research Institute of Agriculture and Life Science, Seoul National University, Seoul 08826, Republic of Korea
| | - Min-Jin Kwak
- Department of Agricultural Biotechnology and Research Institute of Agriculture and Life Science, Seoul National University, Seoul 08826, Republic of Korea
| | - Younghoon Kim
- Department of Agricultural Biotechnology and Research Institute of Agriculture and Life Science, Seoul National University, Seoul 08826, Republic of Korea.
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Yao C, Xia W, Dou M, Du Y, Wu J. Oxidative degradation of UV-irradiated polyethylene by laccase-mediator system. JOURNAL OF HAZARDOUS MATERIALS 2022; 440:129709. [PMID: 35939906 DOI: 10.1016/j.jhazmat.2022.129709] [Citation(s) in RCA: 23] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/16/2022] [Revised: 07/27/2022] [Accepted: 07/31/2022] [Indexed: 06/15/2023]
Abstract
Polyethylene (PE) is one of the most widely used plastics. However, the chemical inertness, inefficient recycling, and random landfilling of PE waste have caused serious pollution to the natural environment. In this study, a series of laccase-mediator systems (LMS) were constructed by combination of two laccases from Botrytis aclada (BaLac) and Bacillus subtilis (BsLac) with three synthetic mediators (ABTS, HBT, and TEMPO) to oxidize LDPE films (UVPE) pretreated with high-temperature UV irradiation. Scanning electron microscopy showed aging phenomena such as etching, fragmentation, and cracking on the surface of the UVPE films after LMS incubation. The FTIR results showed that LMS-UVPE added new oxygen-containing functional groups such as -OH, -CO, and CC. High-temperature gel chromatography confirmed that the average reduction in weight-average molecular weight (Mw) was approximately 40% for the BaLac experimental group. GC-MS analysis showed the presence of oxygen-containing products, such as aldehydes, ketones, and alcohols, in the reaction mixture. To verify the oxidation process UVPE degradation by LMS, we inferred three possible pathways by combined analysis of the oxidation products of LMS on UVPE and model substrates oleic acid and squalene.
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Affiliation(s)
- Congyu Yao
- State Key Laboratory of Food Science and Technology, Jiangnan University, 1800 Lihu Avenue, Wuxi 214122, China; School of Biotechnology and Key Laboratory of Industrial Biotechnology Ministry of Education, Jiangnan University, 1800 Lihu Avenue, Wuxi 214122, China; International Joint Laboratory on Food Safety, Jiangnan University, 1800 Lihu Avenue, Wuxi 214122, China
| | - Wei Xia
- State Key Laboratory of Food Science and Technology, Jiangnan University, 1800 Lihu Avenue, Wuxi 214122, China; School of Biotechnology and Key Laboratory of Industrial Biotechnology Ministry of Education, Jiangnan University, 1800 Lihu Avenue, Wuxi 214122, China; International Joint Laboratory on Food Safety, Jiangnan University, 1800 Lihu Avenue, Wuxi 214122, China
| | - Mingde Dou
- State Key Laboratory of Food Science and Technology, Jiangnan University, 1800 Lihu Avenue, Wuxi 214122, China; School of Biotechnology and Key Laboratory of Industrial Biotechnology Ministry of Education, Jiangnan University, 1800 Lihu Avenue, Wuxi 214122, China; International Joint Laboratory on Food Safety, Jiangnan University, 1800 Lihu Avenue, Wuxi 214122, China
| | - Yanyi Du
- State Key Laboratory of Food Science and Technology, Jiangnan University, 1800 Lihu Avenue, Wuxi 214122, China; School of Biotechnology and Key Laboratory of Industrial Biotechnology Ministry of Education, Jiangnan University, 1800 Lihu Avenue, Wuxi 214122, China; International Joint Laboratory on Food Safety, Jiangnan University, 1800 Lihu Avenue, Wuxi 214122, China
| | - Jing Wu
- State Key Laboratory of Food Science and Technology, Jiangnan University, 1800 Lihu Avenue, Wuxi 214122, China; School of Biotechnology and Key Laboratory of Industrial Biotechnology Ministry of Education, Jiangnan University, 1800 Lihu Avenue, Wuxi 214122, China; International Joint Laboratory on Food Safety, Jiangnan University, 1800 Lihu Avenue, Wuxi 214122, China.
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