Publication Date:
2024-03-06
Description:
Black yeasts comprise a group of Ascomycota of the order Chaetothyriales with highly variable morphology,
\na great diversity of ecological niches and life cycles. Despite the ubiquity of these fungi, their diversity in freshwater
\nsediments is still poorly understood. During a survey of culturable Ascomycota from river and stream sediments
\nin 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
\nspacer region (ITS) and the large subunit (LSU) of the nuclear rDNA revealed that most of the isolates belonged
\nto the family Herpotrichiellaceae. We have confidently identified 30 isolates representing the following species:
\nCapronia pulcherrima, Cladophialophora emmonsii, Exophiala equina, Exophiala pisciphila, Exophiala radicis, and
\nPhialophora americana. However, we encountered difficulty in assigning 17 cultures to any known species within
\nChaetothyriales. Combining phenotypic and multi-locus phylogenetic analyses based on the ITS, LSU, \xce\xb2-tubulin
\n(tub2) and translation elongation factor 1-\xce\xb1 (tef1-\xce\xb1) gene markers, we propose the new genus Aciculomyces in the
\nHerpotrichiellaceae to accommodate the novel species Aciculomyces restrictus. Other novel species in this family
\ninclude Cladophialophora denticulata, Cladophialophora heterospora, Cladophialophora irregularis, Exophiala
\ncandelabrata, Exophiala dehoogii, Exophiala ramosa, Exophiala verticillata and Phialophora submersa. The new
\nspecies Cyphellophora spiralis, closely related to Cyphellophora suttonii, is described, and the phylogeny of the
\ngenus Anthopsis in the family Cyphellophoraceae is discussed. By utilizing these four markers, we were able to
\nstrengthen the phylogenetic resolution and provide more robust taxonomic assessments within the studied group.
\nOur findings indicate that freshwater sediments may serve as a reservoir for intriguing black yeasts, which warrant
\nfurther investigation to address gaps in phylogenetic relationships, particularly within Herpotrichiellaceae.
Keywords:
Ascomycota
;
biodiversity
;
Cyphellophoraceae
;
fluvial sediments
;
Herpotrichiellaceae
;
new taxa
;
phylogeny
;
taxonomy
Repository Name:
National Museum of Natural History, Netherlands
Type:
info:eu-repo/semantics/article
Format:
application/pdf
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