Abstract
Low Density Polyethylene (LDPE) is one of the most important constituents of waste generated, since the time taken for its natural degradation is long. Therefore, this study mainly focused on identifying efficient fungal degraders of LDPE. Partially degraded polyethylene was collected from different places in Kaduwela area, Sri Lanka to isolate the abundant fungi in degrading polyethylene. For biodegradation studies, these fungal isolates were inoculated on streptomycin incorporated potato dextrose agar (PDA) medium which comprised 20-micron LDPE film. After 90 days of incubation, gravimetric analysis, light microscopy, Fourier- Transform Infrared Spectroscopy (FTIR) and Scanning Electron Microscopy (SEM) were conducted to determine the potent of these fungal isolates in degrading LDPE. These fungal isolates were identified by sequencing internal transcribed spacer region (ITS). Multiple alignments of partial sequences were performed by CLUSTAL W and the phylogeny was analyzed using MEGA 6.0 software. According to the one-way Analysis of Variance, the mean values of weight loss of control and Aspergillus niger isolate PS3. (P=0.000), control and Fusarium sp. isolate PS3 (P=0.031) and control and Penicillium sp. isolate PS2 (P=0.010) were significantly different. Scanning electron microscope images and light microscopic observations showed the presence of fungal colonization and surface erosion, cracks, folding and firm fungal attachment. The FTIR spectroscopy images of Fusarium sp. isolate PS3 treated LDPE films showed the early stage of degradation by initiating bonds such as carboxylic bonds and aldehyde bonds. The fungal isolates were identified as Fusarium sp. isolate PS3, Penicillium sp isolate PS2 and Aspergillus niger isolate PS3 by analyzing the ITS region sequencing. Therefore, it can be concluded that the fungal species, Fusarium sp., Aspergillus sp. and Penicillium sp. are capable of colonizing on LDPE films and has the potential to be developed into an inoculum for expedited LDPE degradation.
Highlights
The attention in environmental problems is growing and there are rising demands to develop ecofriendly material which do not harm the environment expressively
[15] The reduction of weight loss of Low Density Polyethylene (LDPE) was observed after 90 days of incubation period because biodegradation is usually proportional to the weight loss of polymer
Because most of the early studies focus on the biodegradation of LDPE using broth cultures but in here solid plate culture technique was applied. 3.2 Microscopic analysis After the initial degradation, crystalline spherolites appeared on the surface of LDPE films that could be observed by the light microscope (Figure 1)
Summary
The attention in environmental problems is growing and there are rising demands to develop ecofriendly material which do not harm the environment expressively. Plastic is a broad name given to different recalcitrant polymers with high molecular weight, which cannot be degraded by biological processes [1]. Identification of potential LDPE degrading microorganisms is vital for further development of environmental biodegradation of low-density polyethylene.
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
