Polystyrene-degrading bacteria in the gut microbiome of marine benthic polychaetes support enhanced digestion of plastic fragments

This study investigates the digestion and degradation of polystyrene foam debris by the benthic clamworm *Perinereis vancaurica*. Analysis of excreted fragments reveals evidence of polystyrene digestion, leading to microplastic formation. 16S rRNA gene sequencing identified a diverse gut microbiome dominated by *Acinetobacter* and *Ruegeria*. Gut isolates of *Acinetobacter johnsonii*, *Brevibacterium casei*, and *Ruegeria arenilitoris* demonstrated polystyrene degradation in vitro, exhibiting slight weight loss, chemical group changes, and the production of metabolic intermediates over 30 days. The findings suggest that polystyrene-degrading bacteria in the clamworm gut influence plastic fragmentation and degradation in marine ecosystems.

Sufang Zhao, Renju Liu, Shiwei Lv, Benjuan Zhang, Juan Wang, Zongze Shao