Screening, identification, and characterisation of bacteria in landfill leachate for polypropylene microplastic biodegradation

Abstract

Plastic contamination is a serious concern for the environment, especially when it comes to microplastics. The biodegradation capability of bacterial strains isolated from landfill leachate against polypropylene microplastics (PPMPs) is examined in this study. A bacterial strain identified as Staphylococcus hominis with 99.77% sequence identity via 16S rRNA gene sequencing showed promising degrading capabilities. Over a 30-day incubation period at 37°C and 150 rpm, S. hominis reduced the weight of PPMPs from 995.2 mg to 833.5 ± 13.85 mg, suggesting a 16.25% degradation. Detailed examinations using bacterial growth tests, Field emission scanning electron microscope (FESEM), and energy-dispersive X-ray spectroscopy (EDS) show significant surface and chemical alterations in the PPMPs, confirming the degradation capability of the bacteria. The bacteria utilised carbon as an energy source, as indicated by the decrease in the percentage weight of molecular carbon from 98% to 78.5%. These findings promote the development of sustainable biological approaches to tackling plastics pollution and show the potential role of bacteria found in landfills, such as S. hominis, in the sustainable bioremediation of microplastic contamination. © 2025 Indian Institute of Chemical Engineers.