Polyethylene Degradation Under Controlled Conditions by Aspergillus sp. Isolated from a Landfill

Petroleum-derived plastics such as polyethylene are the most widely used polymers globally. However, once used, they are often not properly segregated or disposed of. Because they resist biodegradation, they cause persistent environmental contamination. This study aimed to analyze the degradation of low-density polyethylene (LDPE) by filamentous fungi isolated from a solid waste landfill. To achieve this goal, we isolated and characterized LDPE-degrading filamentous fungi via phenotypic and genotypic methods. We also determined their degradation potential on the basis of the physical, mechanical, and chemical characteristics of the polymer after 150 days of incubation with the fungi. We isolated a total of 77 fungal strains, 46.75% of which demonstrated LDPE degradation capabilities. The weight loss of the polymer after treatment with the degrading fungi ranged from 4.44% to 20.21%, with a reduction rate of 0.000307 to 0.001504 grams per day and a residual half-life of 450.06 to 2257.65 days. Furthermore, 27.78% of the fungi reduced the tensile strength of the LDPE fragments by 5.61% to 41.72%. Compared with the control, the Aspergillus sp. 40 CIFOS strain presented the most significant physical and chemical changes in the degraded polymer. In conclusion, fungi isolated from solid waste landfills have a high capacity for LDPE degradation. These results, obtained under laboratory conditions, encourage future studies focused on the application of biotechnological processes and the identification of enzymes involved in the degradation process to optimize the bioremediation of contaminated environments.