Isolation and Screening of Polyethylene Terephthalate (PET)-degrading bacteria from Municipal Waste Disposal Site in West Java, Indonesia

Abstract

Polyethylene terephthalate (PET) is a persistent plastic contributing to environmental pollution due to its resistance to natural degradation. This study aimed to identify PET-degrading bacteria from two major landfills in West Java, that is Bantar Gebang and Cipayung. Samples were collected from soil and plastic waste at three locations per site. A combined approach was used: metagenomic analysis to profile microbial diversity, and culturable enrichment using PET-supplemented mineral medium followed by isolation and PEG-based clear zone screening. PET degradation was assessed over 21 days using PET film as the sole carbon source, and surface damage was evaluated via scanning electron microscopy (SEM). Metagenomic analysis revealed high microbial diversity dominated by Pseudomonadota and Bacillota, suggesting potential for PET degradation. From 34 culturable isolates, six exhibited clear zone activity: BP8, CT9, CT11 (Bantar Gebang) and ET4, EP19, FP20 (Cipayung). SEM and relative enzyme activity assays confirmed PET film degradation, particularly in isolates BP8 and EP19. Molecular identification via 16S rRNA sequencing revealed high similarity of BP8 to Priestia megaterium, CT9 to Comamonas terrae, CT11 and FP20 to Brucella pseudintermedia, ET4 to Shinella yambaruensis, and EP19 to Micrococcus luteus. These results highlight the potential of landfill-derived bacteria for PET biodegradation and offer candidates for further biotechnological development in plastic waste management. ImportancePlastic pollution is a growing problem, especially in landfills where it can remain for decades without breaking down. This study looked for bacteria in two major landfills in West Java, Indonesia, that might help degrade PET, a common plastic used in bottles and packaging, using a combination of two scientific approaches: metagenomics (analyzing microbial DNA directly from the environment) and culturable methods (growing microbes in the lab). By combining different scientific methods, we were able to find several types of bacteria that show early signs of being able to break down PET in the lab. While further studies are needed to confirm how well these microbes work and how they break down plastic, these initial findings provide a useful starting point for developing biological methods to manage plastic waste more sustainably in the future.