Biodegradation potential of Low-Density Polyethylene (LDPE) by soil-inhabiting ascomycetous microfungi isolated from urban dumpsites

Urban dumpsites are excellent sources of microbes which can biodegrade numerous materials present in waste. This study focused on the assessment of the mycodegradation potential of LDPE (Low-Density Polyethylene) by ascomycetous microfungi from urban dumpsites in Sri Lanka. Out of the collection obtained from five localities in Sri Lanka, eight species of ascomycetes, viz. Talaromyces purpureogenus (GF85), T. beijingensis (GGF03), Penicillium citrinum (GF89), Purpureocillium lilacinum (GF99), Aspergillus flavus (GF94), Aspergillus sp. (GF82), A. terreus (MMF08), and Fusarium falciforme (GF77), demonstrated mycodegradation potential based on the primary screening. All the isolates were accurately identified based on morphology, Sanger sequencing, and phylogenetic analysis of nuclear internal transcribed spacer region with 5.8 s ribosomal DNA (ITS). Among the isolates, T. purpureogenus GF85 showed a 13–17% weight reduction of LDPE. The same fungus showed evidence of remarkable ability to cause biodeterioration of LDPE by Fourier-transform infrared spectroscopy (FTIR) and Scanning Electron Microscopy (SEM). This study highlights the significance of extensive sampling, morphological, molecular characterisation, and comparative analysis of fungi from unexplored habitats towards developing sustainable solutions for the polyethylene waste crisis.