Exophiala crusticola anam. nov. (affinity Herpotrichiellaceae), a novel black yeast from biological soil crusts in the Western United States.

A novel black yeast-like fungus, Exophiala crusticola, is described based on two closely related isolates from biological soil crust (BSC) samples collected on the Colorado Plateau (Utah) and in the Great Basin desert (Oregon), USA. Their morphology places them in the anamorphic genus Exophiala, having affinities to the family Herpotrichiellaceae (Ascomycota). Phylogenetic analysis of their D1/D2 large subunit nuclear ribosomal RNA (LSU nrRNA) gene sequences suggests that they represent a distinct species. The closest known putative relative to Exophiala crusticola is Capronia coronata Samuels, isolated from decorticated wood in Westland County, New Zealand. The holotype for Exophiala crusticola anam. nov. is UAMH 10686 and the type strain is CP141bT (=ATCC MYA-3639T=CBS 119970T=DSM 16793T). Dark-pigmented fungi appear to constitute an important heterotrophic component of soil crusts and Exophiala crusticola represents the first description of a dematiaceous fungus isolated from BSCs.