Directed assembly of biofilm communities for marine biofouling prevention.

Bio-based solutions depend on the application of living organisms to combat current challenges, including marine biofouling, which is characterized by the adhesion and growth of organisms on surfaces at sea. Such solutions traditionally involve single bacterial strains with specific, desirable activities or properties, thereby omitting the advantages conferred by the community context. We propose a novel approach, whereby desirable emergent properties of multispecies communities can be selected, such as those producing a thick and robust biofilm that is impenetrable to settling larvae. Here, bacterial biofilms from natural and artificial marine surfaces were studied, focusing on their adhesion, cohesion, stability, and antifouling properties both as single isolates and in multispecies communities. Using bottom-up assembly, we identified multispecies biofilm communities that exhibited greater tolerance to temperature variations compared to the component species. Additionally, some isolates, alone or as multispecies biofilms, prevented the settlement of barnacle larvae in short-term laboratory biofouling experiments. Broadly, our findings highlight the complexity of bacterial interactions within biofilms, revealing competition with occasional cooperation. More specifically, we present the possibility of a novel approach to biofouling control, whereby communities of marine isolates produce biofilms with the physical properties of a protective coating and, thus, move the industry a step toward environmentally friendly, regenerative antifouling coatings.IMPORTANCEMarine biofouling poses a significant challenge to maritime industries, resulting in lower efficiency, higher maintenance costs, environmental impact and structural damage. Marine antifouling coatings are the first line of defense against biofouling and their biocidal mechanism of action has remained largely unchanged for decades. Although the concept of "living coatings" has been mooted previously, we take a novel approach. By exploiting useful emergent properties from multispecies communities, we propose that the resulting biofilms will be more environmentally stable than single-species biofilms, allow departure from a focus on active protection via toxic metabolites, and will eventually enable the development of biological coatings with desirable physical properties. By highlighting the competitive and cooperative dynamics within biofilms, the research identifies microbial communities that reduce barnacle larval settlement while tolerating environmental stressors like temperature variation. These findings are a first step towards eco-friendly, biofilm-based antifouling strategies that are both self-regenerating and environmentally compatible.