Diversity and novel lineages of black yeasts in from freshwater sediments in Spain.

Black yeasts comprise a group of of the order with highly variable morphology, a great diversity of ecological niches and life cycles. Despite the ubiquity of these fungi, their diversity in freshwater sediments is still poorly understood. During a survey of culturable from river and stream sediments in various sampling sites in Spain, we obtained 47 isolates of black yeasts by using potato dextrose agar supplemented with cycloheximide. A preliminary morphological study and sequence analyses of the internal transcribed spacer region (ITS) and the large subunit (LSU) of the nuclear rDNA revealed that most of the isolates belonged to the family . We have confidently identified 30 isolates representing the following species: , , , , , and . However, we encountered difficulty in assigning 17 cultures to any known species within . Combining phenotypic and multi-locus phylogenetic analyses based on the ITS, LSU, β-tubulin (2) and translation elongation factor 1-α (1-α) gene markers, we propose the new genus in the to accommodate the novel species . Other novel species in this family include , , , , , , and . The new species , closely related to , is described, and the phylogeny of the genus in the family is discussed. By utilizing these four markers, we were able to strengthen the phylogenetic resolution and provide more robust taxonomic assessments within the studied group. Our findings indicate that freshwater sediments may serve as a reservoir for intriguing black yeasts, which warrant further investigation to address gaps in phylogenetic relationships, particularly within . : Torres-Garcia D, García D, Réblová M, et al. 2023. Diversity and novel lineages of black yeasts in Chaetothyriales from freshwater sediments in Spain. Persoonia 51: 194-228. doi: 10.3767/persoonia.2023.51.05.