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

Abstract

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.

Floral and Foliar Source Affect the Bee Nest Microbial Community

“…Specifically, when comparing the fungi found in alfalfa versus Phacelia treatments, we found differentially abundant ESVs including Alternaria, which are saprophytic fungi that are commonly found in soil and on decaying plants and can act as major plant pathogens causing blight in multiple crops [61] and have been previously identified in M. rotundata larval guts [ 6 2 ] . A b u n d a n t f u n g a l r e a d s c o r r e s p o n d i n g t o Golovinomyces (one of the causative agents of powdery mildew) [63] were found in our samples, as well as Phaeococcomyces (a genus of potentially pathogenic black yeast) [64], the mild plant pathogen Pezicula heterochroma [65], an ESV of Ustilago smut fungus [66], of which this taxon has been previously found in M. rotundata [62], an ESV of the leaf spot disease agent Stemphylium eturmiunum [67], the pink rot fungus Trichothecium roseum [68], and the widespread putative opportunistic bee pathogen Aspergillus niger [23,62]. We found many other genera and unique ESVs in lesser abundance including the chalkbrood-causing fungus Ascosphaera aggregata [3], Debaryomyces hansenii, which has been previously isolated from stingless bees [69], and Colletotrichum trifolii, an important pathogen of alfalfa.…”

A culture‐independent study of free‐living fungi in biological soil crusts of the Colorado Plateau: their diversity and relative contribution to microbial biomass

“…In any event, these phylotypes were neither widespread nor abundant. Although potentially crust‐specific fungi have been discovered, namely Exophiala crusticola (Bates et al ., 2006), renewed cultivation efforts will be needed before the function and identities of these sort of fungi can be elucidated. Further analysis of additional sites, across a larger geographic range, with better phylogenetic resolution, and with polyphasic approaches that can match phylotypes directly to isolates, will also be necessary before the presence of BSC‐exclusive fungal flora can be properly addressed.…”

Fungal communities of lichen-dominated biological soil crusts: Diversity, relative microbial biomass, and their relationship to disturbance and crust cover

“…Although yeast have been reported in other crust surveys (States and Christensen, 2001), this study is the first to suggest that they may be among the more prominent members of some arid land BSC fungal communities. A novel crustdwelling black yeast, Exophiala crusticola, has also been isolated from two geographically distant western BSC sites (Bates et al, 2006). E. crusticola has the ability to survive on cyanobacterial exudates, which likewise points to the fact that yeasts may be an integral component of BSCs.…”