Genomic and Enzymatic Analysis of Polyethylene Biodegradation by Pseudomonas Fluorescens Jnu01 Isolated from Landfill Environments

Abstract

Microbes can biodegrade accumulated plastics in various environments. However, it remains unclear whether they can utilize high molecular weight polymers as a sole carbon source. Here, we report the isolation of a novel polyethylene (PE)-degrading bacterium, Pseudomonas fluorescens JNU01 from landfill samples, an environment enriched with microbiome consortia adapted to PE waste. Unlike non-PE-degrading reference strain P. fluorescens strains DR133, screened P. fluorescens strain JNU01 demonstrated remarkable growth (OD600 of 0.9 within 2 days) with PE as its sole carbon source. Comparative genomic analysis between JNU01 and non-PE-degrading reference strain DR133 revealed the exclusive presence of alkane monooxygenase (AlkB) and Baeyer-Villiger monooxygenase (BVMO) genes, physically clustered within the same genetic locus. FT-IR spectroscopy showed characteristic hydroxyl peaks (3,300–3,400 cm–1) in JNU01-treated PE. SEM analysis revealed significant surface modification, including micro-size embossed patterns and increased hydrophilicity. GC-MS identified 15 distinct metabolites, including alkanes, alkanols, and acid products, indicating a possible oxidative PE cleavage pathway. Functional analysis of recombinant AlkB confirmed its capacity to introduce hydroxyl, carboxyl, and amide groups on PE surfaces, supporting its critical role in initiating PE biodegradation. These findings uncover a strain-specific mechanism of PE degradation and offer a genomic framework for engineering microbial solutions to plastic waste.

Keywords: Polyethylene biodegradation, Pseudomonas fluorescens JNU01, Comparative genomics, Alkane monooxygenase, Baeyer-Villiger monooxygenase, Microbial plastic degradation