Screening of a polyethylene terephthalate hydrolase (PETase)-like enzyme from the wastewater microbial consortium

Plastics, especially single-use varieties like PET, have witnessed a significant surge in production in recent decades. However, this increase has raised concerns about plastic pollution and the potential threat of microplastics to various organisms in the environment. The study aimed to identify microbes capable of breaking down PET plastic. Plasticdegrading microbes were screened using the enrichment technique from environmental sources. Candidate strains were obtained from Bangsue wastewater and then subjected to tests with the plate clearing assay, using BHET as an indicator. The study found PET-degrading bacteria thrived at 55°C, shown by high broth turbidity in the enriched sample. The best candidates were selected for the dot assay test based on their activity. The top three candidates, BNJ24, BNJ26, and BNJ27, exhibited clear zone sizes ranging from 7 to 10 mm observed after three days. They were then tested for PET bottle plastic treatment. BNJ26 showed the highest plastic degradation with a surface hydrophobicity of 74.42±3.25° on day 5, which was lower than that of BNJ24 and BNJ27 (80.59±6.04° and 77.30±6.19°, respectively). After 7 days of incubation, degradation products were identified in BNJ26. Our findings identified BNJ26 as the best candidate for PET degradation within the microbial consortium.