Polymer type drives successional structural and functional organization of plastisphere microbial networks

Plastics provide novel niches for diverse microbial communities, collectively known as the plastisphere. However, the successional structural and functional patterns of these microbial communities remain poorly understood. Here, we investigated microbial assemblages colonizing three biodegradable (PBAT, PBSJ, PBSM) and two non-biodegradable (PET, PS) polymers through an eight-week time-series in situ incubation in coastal seawater. Distinct microbial communities developed across polymer types, revealing clear polymer-driven differentiation within the plastisphere. Co-occurrence network analysis further showed that these communities were organized into modular structures representing ecologically distinct niches. Each module tracked successional transitions over time and exhibited specialized functional characteristics. Together, these findings demonstrate that polymer type strongly governs both the structural and functional organization of plastisphere microbial communities, providing new insights into their ecological and biogeochemical roles in marine environments.