fig7

Figure 7. SEM images of PS MP surfaces after 30 days under different conditions. (A) Control PS surface showing smooth, unaltered morphology in the absence of bacterial treatment; (B) PS surface inoculated with bacteria, exhibiting dense biofilm formation with EPS aggregates indicating active microbial colonization. A magnified image at 5 μm is also shown; (C) PS surface after biofilm removal, displaying visible surface degradation such as cracks, pits, and erosion, signifying post-biofilm structural alterations caused by bacterial activity. SEM: Scanning electron microscopy; PS: polystyrene; MP: microplastic; EPS: extracellular polymeric substance.