Metaproteomic profiling of a granule-forming Ca. Accumulibacter enrichment

Extracellular proteins play key roles in microbial biofilm and aggregate formation, yet remain poorly understood. Using two advanced metaproteomic techniques, this study identified and classified 387 extracellular proteins potentially involved in aggregate formation, including filamentous and cell surface proteins from various organisms. The findings suggest that diverse proteins from multiple organisms support the granular biofilm formation in the investigated Ca. Accumulibacter enrichment, providing a valuable resource for studying the scope of extracellular proteins.