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Khan S, Ali SA, Ali AS. Biodegradation of low density polyethylene (LDPE) by mesophilic fungus ' Penicillium citrinum' isolated from soils of plastic waste dump yard, Bhopal, India. ENVIRONMENTAL TECHNOLOGY 2023; 44:2300-2314. [PMID: 34994296 DOI: 10.1080/09593330.2022.2027025] [Citation(s) in RCA: 17] [Impact Index Per Article: 17.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/17/2021] [Accepted: 12/22/2021] [Indexed: 06/04/2023]
Abstract
Low density Polyethylene (LDPE) in various forms has become a part of life. Its accretion due to non degradable nature is concern, endangering life on earth. Amongst various methods of LDPE disposal bioremediation is regarded as ecofriendly & widely accepted. Current investigation was an attempt to isolate potent PE degrading fungus from municipal landfill soils of Bhopal, India loaded with plastic waste.16 fungal isolates were recorded from the site; PE deteriorating fungus was screened using mineral salt agar medium amended with 3% LDPE powder as sole carbon source. The isolate Penicillium citrinum showed fast fungal colony growth in screening medium was selected for biodegradation study. P.citrinum showed 38.82 ± 1.08% weight loss of untreated LDPE pieces; to improve the degradation capacity nitric acid pretreatment was performed; biodegradation was significantly stimulated by 47.22 ± 2.04% after it's pretreatment. Laccase, lipase, esterase & manganese peroxidase activities were assayed by spectrophotometer. LDPE biodegradation was analyzed by weight loss %, change in pH during fungal growth, field emission scanning electron microscopy (FE-SEM), fourier transform infrared spectroscopy (FTIR) & thermogravimetric analysis (TGA). FTIR spectra showed appearance of new functional groups assigned to hydrocarbon biodegradation, confirming enzymatic role in process. Changes in FTIR spectra of LDPE samples (untreated & pretreated) before & after biodegradation & surface changes in the biodegraded LDPE (indicated from FE-SEM) confirmed depolymerization of LDPE. Further changes in thermal decomposition rates of biodegraded samples in comparison to control, validate biodegradation. This is the first report signifying high competence of P.citrinum in LDPE degradation without prior pretreatment.
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Affiliation(s)
- Shazia Khan
- Department of Biotechnology and Bioscience, Saifia College of Science, Barkatullah University, Bhopal, India
| | - Sharique A Ali
- Department of Biotechnology and Bioscience, Saifia College of Science, Barkatullah University, Bhopal, India
| | - Ayesha S Ali
- Department of Biotechnology and Bioscience, Saifia College of Science, Barkatullah University, Bhopal, India
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Hou L, Xi J, Liu J, Wang P, Xu T, Liu T, Qu W, Lin YB. Biodegradability of polyethylene mulching film by two Pseudomonas bacteria and their potential degradation mechanism. CHEMOSPHERE 2022; 286:131758. [PMID: 34399255 DOI: 10.1016/j.chemosphere.2021.131758] [Citation(s) in RCA: 38] [Impact Index Per Article: 19.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/04/2021] [Revised: 07/07/2021] [Accepted: 07/30/2021] [Indexed: 06/13/2023]
Abstract
Wasted polyethylene (PE) products caused pollution has become a global issue. Researchers have identified PE-degrading bacteria which have been considered as a sustainable alleviation to this crisis. However, the degradation mechanism employed by currently isolated bacteria is unclear and their degradation efficiencies are insufficient. More importantly, there is little research into bacteria capable of degrading PE mulching film to solve "white" pollution in agriculture. We determined the PE degradation efficiency of two Pseudomonas, identified by 16S rDNA analysis, and elucidated their potential mechanisms through whole genome sequencing. During an 8-week period, PE mulch lost 5.95 ± 0.03% and 3.62 ± 0.32% of its mass after incubated with P. knackmussii N1-2 and P. aeruginosa RD1-3 strains, respectively. Moreover, considerable pits and wrinkles were observed on PE.The hydrophobicity of PE films also decreased, and new oxygenic functional groups were detected on PE mulch by Fourier Transform Infrared Spectrometry (FTIR). Complete genome sequencing analysis indicated that two Pseudomonas strains encode genes for enzymes and metabolism pathways involved in PE degradation. The results provide a theoretical basis for further research that investigates the mechanism driving the degradation and metabolism of discarded PE in the environment.
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Affiliation(s)
- Lijun Hou
- College of Life Sciences, Northwest A&F University, Yangling, Shaanxi, 712100, PR China; Department of Natural Resource Sciences, Macdonald Campus, McGill University, Ste-Anne-de-Bellevue, QC, H9X 3V9, Canada
| | - Jiao Xi
- College of Life Sciences, Northwest A&F University, Yangling, Shaanxi, 712100, PR China
| | - Jiaxi Liu
- College of Life Sciences, Northwest A&F University, Yangling, Shaanxi, 712100, PR China
| | - Peiyuan Wang
- College of Life Sciences, Northwest A&F University, Yangling, Shaanxi, 712100, PR China
| | - Tengqi Xu
- College of Life Sciences, Northwest A&F University, Yangling, Shaanxi, 712100, PR China
| | - Tingting Liu
- College of Science, Northwest A&F University, Yangling, Shaanxi, 712100, PR China
| | - Wenxing Qu
- College of Life Sciences, Northwest A&F University, Yangling, Shaanxi, 712100, PR China
| | - Yan Bing Lin
- College of Life Sciences, Northwest A&F University, Yangling, Shaanxi, 712100, PR China.
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Sales JCS, Santos AG, de Castro AM, Coelho MAZ. A critical view on the technology readiness level (TRL) of microbial plastics biodegradation. World J Microbiol Biotechnol 2021; 37:116. [DOI: 10.1007/s11274-021-03089-0] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2021] [Accepted: 06/07/2021] [Indexed: 12/26/2022]
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