Biofilm induction and tolerance to invasion of marine bacterial communities

Background Marine microorganisms form highly diverse microbial ecosystems that play critical roles in surface colonization and biofouling dynamics. Traditional antifouling approaches largely rely on chemical coatings, raising environmental concerns particularly in aquatic ecosystems. This work aims to explore the emergent properties of natural marine multispecies communities to develop stable underwater biofilms tolerant to external microbial invasion, as a foundation for future biofilm-based antifouling approaches. Results Using a bottom-up assembly approach, we constructed multispecies biofilm communities from 161 marine bacterial isolates. Initial high-throughput screening on treated and untreated polystyrene material identified top biofilm formers in monoculture, which were further validated on the PSX700-coated surfaces, a polysiloxane material widely used on underwater vehicles and other marine, underwater infrastructures. Selected isolates were combined into multispecies communities and tested for biofilm biomass, community stability, and extent of invasion by Pseudoalteromonas tunicata . Several multispecies communities exhibited significant biofilm induction and compositional stability compared to their component species. Furthermore, communities assembled with tolerant isolates showed strong tolerance to P. tunicata invasion, suggesting that community-level invasion tolerance may be associated with the component species. Conclusion Together, these findings demonstrate that rational assembly of marine bacterial communities can generate stable, invasion-tolerant biofilms. This study provides a foundation for the potential of targeted biofilm assembly toward environmentally friendly, biofilm-based living coatings for marine applications.