Biodegradation of polyethylene by indigenous soil bacteria isolated from municipal landfill sites of Mangaluru.

Polyethylene (PE) is a widely used synthetic polymer whose resistance to degradation poses a significant environmental challenge. In this study, landfill soils from municipal waste disposal sites in Mangaluru, India, were explored as potential sources of PE-degrading bacteria. Bacterial isolates were screened for their ability to utilize PE as a carbon source, and selected isolates were evaluated for degradation-related activity. Among the tested isolates, the highest PE weight reduction observed after 30 days was 15.38%. Physicochemical characterization of PE films revealed structural alterations, oxidative functional group formation, and surface damage following bacterial treatment. In addition, the laccase assay indicated a significant increase in the enzyme activity during the study period, highlighting the involvement of oxidative pathways. Among the PE-degrading genes screened, alkB was detected in all tested isolates. Molecular identification based on 16S rRNA gene sequencing revealed four bacterial species, among which Escherichia fergusonii and Leclercia adecarboxylata are reported for the first time as PE degraders. Overall, the findings highlight landfill environments as reservoirs of metabolically diverse microorganisms with potential relevance for future plastic biodegradation and bioremediation studies. Further studies focusing on enzymatic mechanisms and process optimization are essential to enhance biodegradation efficiency and enable large-scale applications.