Isolation and Characterization of Polyethylene-Degrading Bacteria from Municipal Dumpsite Soils of Gujarat, India

Abstract

Plastic waste accumulation, particularly polyethylene, poses a significant environmental challenge due to its recalcitrant nature and persistence in ecosystems. The present study aimed to isolate, characterize, and evaluate polyethylene‑degrading bacteria from municipal dumpsite soils collected from Kalol (Gandhinagar) and Pirana (Ahmedabad), Gujarat, India. Soil samples were enriched in mineral salt medium (MSM) supplemented with polyethylene as the sole carbon source, followed by isolation and characterization of bacterial strains using morphological, biochemical, and molecular approaches. Two bacterial isolates were obtained and identified through Gram staining, biochemical profiling, and 16s rRNA gene sequencing as Bacillus paramycoides and Pseudomonas aeruginosa. Biochemical analysis revealed distinct metabolic capabilities, with Pseudomonas aeruginosa exhibiting stronger metabolic activities associated with polymer degradation. In weight‑loss assays, Bacillus paramycoides and Pseudomonas aeruginosa caused 3.59 ± 0.01 % and 4.85 ± 0.24 % mass loss of polyethylene films, respectively, after 90 days of incubation in MSM. FTIR analysis confirmed the appearance of new oxygen‑containing functional groups on the polymer surface after bacterial treatment, indicating oxidative degradation of polyethylene. These findings demonstrate that municipal dumpsite soils are valuable reservoirs of polyethylene‑degrading bacteria and highlight the potential application of Bacillus paramycoides and Pseudomonas aeruginosa in eco‑friendly plastic waste management strategies. Keywords: Isolation Characterization LDPE degrading bacteria 16s rRNA sequencing weight loss FTIR