Decoding the biodegradation potential of Rhodococcus pyridinivorans towards low-density polyethylene

Polyethylene (PE) waste is one of the major ecological problems because of its recalcitrant nature for environmental degradation. Despite the conventional methods of plastic waste management, biological approaches are gaining particular attention as a sustainable alternative for its management. Recent research has shown several indigenous microbes capable of degrading different types of polyethylene. Herein, we isolated and identified the bacterium, Rhodococcus pyridinivorans, which has shown the capability to degrade with UV pre-treated low-density polyethylene (LDPE). A systematic study was conducted for 130 days to highlight the association of R. pyridinivorans with LDPE and its ability to cause morphological and weight loss changes in the polyethylene. The changes on bacterial treated PE surfaces were observed with scanning electron microscopy and atomic force microscopy analysis. The potential of R. pyridinivorans to cause surface changes is also confirmed with 18% reduction and 15% increment in carbon and oxygen content, respectively. Further, R. pyridinivorans treatment induces hydroxyl and carbonyl groups, which results in an overall reduction in hydrophobicity of PE sheets. Overall, these findings demonstrate that R. pyridinivorans can associate with polyethylene for its survival. Bioinformatic analysis revealed a conserved domain (PF00487) in alkane monooxygenase, potentially involved in LDPE surface changes. In future, the genomic and proteomic analysis of R. pyridinivorans may provide a better understanding of the molecular mechanism of PE degradation that could be employed as an alternative strategy for removing polyethylene waste from the environment.