Talaromyces marinus (Eurotiales, Trichocomaceae): A new marine fungus from the Red Sea, Egypt, with distinguished enzymatic capabilities

Background Talaromyces is a large and taxonomically important genus within Ascomycota, established to accommodate the teleomorphs of certain Penicillium species and now recognized as a monophyletic lineage distinct from Penicillium . Multigene analyses demonstrated that species formerly placed in Penicillium subgenus Biverticillium belong within Talaromyces , leading to their reclassification under the single-name nomenclature system. Currently, the genus comprises 237 species arranged into nine sections supported by multilocus phylogeny. Species of Talaromyces are cosmopolitan, occurring in diverse habitats and substrates. It is notable for their medical, industrial, and ecological significance. In Egypt, several species of Talaromyces have been reported from a variety of substrates, highlighting the regional diversity and ecological relevance of the genus. Results A new marine taxon, Talaromyces marinus is recorded from decaying woody samples of Avicennia marina , collected from Wadi El-Jimal area, Red Sea Governorate, Egypt. Multi-locus analyses of the combined ITS (internal transcribed spacers of rDNA), LSU (nuclear large subunit rDNA), BenA (β-tubulin), and RPB2 (RNA polymerase II second largest subunit) sequences dataset placed the new species within Talaromyces section Trachyspermi series Diversi but distinct from previously described species. The new taxon is characterized by restricted growth on different media, long stipes, biverticillate penicilli, the shortest acerose phialides in series Diversi , globose to subglobose or ellipsoidal, smooth-walled conidia, acid production, and soluble pigments. Conclusion Talaromyces marinus sp. nov. is described, illustrated, phylogenetically analyzed, and its enzymatic potential is evaluated, it also compared with other species in the section Trachyspermi series Diversi .