Degradation of polymers by fungi isolated from dumpsites

Abstract The present study aims at identifying the ability of nine fungal species isolated from the garbage of different sites to degrade polyethylene, polystyrene, and polyurethane when treated separately with the drench and mulching methods, each one sterilized and unsterilized for four months. The species considerably decomposed the polymers by these methods. Polystyrene demonstrated the highest degradation compared to the other polymers, particularly by sterilized and unsterilized drench methods. Seven fungal species showed greater than 50% weight loss of polystyrene when treated with these methods. Aspergillus flavus instigated the highest weight loss (74.78 ± 2.85%) by the unsterilized drench method. Of nine, three species caused more than 50% weight loss of polyurethane by the unsterilized drench method. A. niger reduced more than half the weight of the polymer by the sterilized drench method. In this study, polyethylene was found least degraded compared to polystyrene and polyurethane by the selected fungal species. Of nine, only two species, viz. Aspergillus flavus and A. niger caused a higher than 50% weight loss of polyethylene only by sterilized drench method. Scanning Electron Microscopy (SEM) images of six highly degraded polymer samples revealed the formation of spores, hyphae, cracks, and crevices on their surfaces.