Discovery of a polyethylene biodegradable laccase from Acinetobacter dijkshoorniae

Abstract Plastic waste management, especially polyethylene (PE), is a global challenge due to its chemical inertness and resistance to degradation. Herein, we isolated a bacterial strain, Acinetobacter dijkshoorniae PE‐9, which can degrade PE films. Over 40 days, the strain reduced the film weight by 5.1%, with degradation confirmed by SEM, FTIR, water contact angle (WCA), and GPC analysis. Using whole‐genome sequencing, transcriptomics, and sequence similarity network analysis, we identified the key degradation enzyme, a multicopper oxidase (AcMCO). The crude AcMCO reduced the WCA of PE films from 97.0° to 60.1%, with its effect supported by SEM and GC–MS analysis. Molecular dynamics simulations revealed the AcMCO‐PE interaction pattern, identifying a methionine‐rich region (AcMCO‐MetRich, residues 328–446) crucial for binding to the PE surface. These findings provide insights into microbial PE degradation and the potential of AcMCO in enhancing plastic recycling.