Endophytic Fungi Isolated from the Brown Alga Sargassum thunbergii in Coastal Korea.

Endophytic fungi associated with seaweeds have increasingly attracted attention due to their ecological roles and potential as biological resources. In this study, fungal endophytes were isolated from the brown alga Sargassum thunbergii, collected in intertidal habitats of Seongsan-eup, Jeju-do and Buan-gun, Jeollabuk-do, Korea. Identification was carried out using an integrative approach that combined morphological characterization with multilocus phylogenetic analyses of ITS, LSU, SSU, TUB2, RPB2, and CaM sequences. Six fungal taxa were identified as new records for Korea: Botryotrichum murorum, Hypomontagnella spongiphila, Subramaniula cristata, Parachaetomium perlucidum, Palmiascoma acericola, and Aspergillus clavatophorus. Detailed morphological descriptions and phylogenetic analysis supporting the identification of these species are provided. These findings expand our knowledge of fungal diversity associated with S. thunbergii and highlights the ecological importance and potential applications of seaweed-associated endophytes in Korea.