Peacock's tail with a fungal cocktail: first assessment of the mycobiota associated with the brown alga Padina pavonica

The microbial diversity of the Mediterranean Sea is still poorly investigated, and a greater effort is needed to reveal marine fungal biodiversity associated with algal substrates. This study is the first description of the cultivable mycobiota associated with the calcareous brown alga Padina pavonica. Twenty algal thalli were analysed with a polyphasic approach, combining morphological and molecular data for fungal identification. Our data reveal a surprising richness of fungal species associated with a single brown alga: 268 isolates belonging to 134 taxa ascribable to Ascomycota (95.3%), Basidiomycota (5.2%), and Mucoromycota (0.7%) were retrieved. Twenty-nine species were reported for the first time from a marine environment. The analyses of the fungal community revealed possible substrate specificity. In addition, a number of sterile strains form separate clusters within the Diaporthales, Hypocreales, and Pleosporales, indicating that putative new lineages may arise from the marine environment.