Construction of an efficient polystyrene-degrading microbial consortium based on degrading and non-degrading bacteria predominant in biofilms of marine plastic debris

Expanded polystyrene (EPS) has caused significant pollution in marine environments, with potential EPS-degrading bacteria identified on long-term floating EPS biofilms. However, studies on bacterial interactions and consortium reconstruction based on in-situ bacterial diversity remain limited. Marine EPS wastes of different sizes were collected from subtropical coast of Xiamen island, and subjected to bacterial diversity analyses. Co-occurrence network and bacterial characterization revealed that Rhodobacterales and Rhizobiales play important roles in polystyrene (PS) degradation. Bacterial isolation characterization confirmed that Fulvimarina pelagi , Pseudosulfitobacter pseudonitzschiae , Devosia nitrariae , Cytobacillus kochii , and Cytobacillus oceanisediminis as novel PS-degraders. Based on their abundance in situ and PS degradation activity, a consortium was constructed, constituted of F. pelagi , P. halotolerans . and O. granulosus , showed a high degradation capability with PS weight loss by 18.9% in 45 days. These results contribute to marine plastic pollution remediation and resources recycling.