A seasonal assessment of in situ marine fungal biofilm communities on artificial reefs

This study was the first characterization of natural mixed-species fungal biofilm communities on artificial reefs in the marine environment. Previous fungal biofilm studies have failed to observe the naturally occurring biodiversity in coastal areas, which are the most utilized zone of the marine environment. Fungi have evolved to form biofilms for protection, to communicate via quorum sensing, to gain access to nutrients, and to exchange genetic information. Furthermore, these communities fuel many primary consumers that support artificial reef habitats. Fungi, along with bacteria, archaea, protists, algae, and diatoms, quickly form a complex biofilm on immersed surfaces in seawater. This settlement and succession calls for further examination, given the major trophic implications therein, as properties of this biofilm will influence future establishment of other marine organisms. For this study, an optimized extraction technique for fungal DNA from biofilm was developed. The fungal biofilm communities were characterized by morphological identification, ITS T-RFLP analysis, and by ITS gene sequencing. The role of seasonality and other abiotic factors in structuring these communities are also being examined. Fungal biodiversity in these biofilms is high, spanning over 25 genera, including species from the Ascomycetes, Zygomycetes, and potential novel yeast species. This assessment of fungal biofilm communities yields insight into artificial reef microbial succession and functionality.