Xerotolerant fungi in house dust: taxonomy of Spiromastix, Pseudospiromastix and Sigleria gen. nov. in Spiromastigaceae (Onygenales, Eurotiomycetes)

Abstract

During a global investigation of fungi in house dust, we isolated six novel arthroconidial fungi. Phylogenies from combined analysis of nuc rDNA 18S, 28S and internal transcribed spacers sequences demonstrated that these fungi and two species preserved in culture collections represent undescribed species of Spiromastigaceae, Onygenales. Seven of the eight species lacked sexual states and only characters of asexual states and growth rates on different media could be used to characterize them. The eighth species produced ascomata only on water agar. We introduce six new species and one new combination in Spiromastix and validate the recently proposed family Spiromastigaceae, genus Pseudospiromastix and combination Ps. tentaculata. The new genus Sigleria is proposed for two new species that differ from Spiromastix by conidiophore branching patterns, slower growth and a limited ability to utilize nitrate as a sole N source. A key to the three genera of Spiromastigaceae, Spiromastix, Pseudospiromastix and Sigleria, is provided. Phylogenetic analyses support the placement of Spiromastigaceae within Onygenales.

AspergillussubgenusPolypaecilumfrom the built environment

“…Xerophilic Aspergillus species are common in the built environment, especially members of sections Aspergillus and Restricti ( Samson et al., 2010 , Chen et al, 2017 , Sklenář et al, 2017 , Visagie et al., 2017 ). One of our two primary isolation media was MEA20S, a reduced a w medium that favors the isolation of moderately xerotolerant species ( Visagie et al., 2014 , Hirooka et al., 2016 ), some of which conform with Pitt's (1975) definition as true xerophiles. The results presented demonstrate the presence of xerotolerant and halotolerant species of subgenus Polypaecilum from indoor dust, with seven species isolated.…”

“…2015 ). The genus Sigleria was described by Hirooka et al. (2016) for two moderately xerotolerant species, S. amend and S. carmichaelii , isolated from the Mexican, Micronesian, and Thai dust samples.…”

“…Research on the mycobiota of the built environment traditionally focused on mesophilic fungi, especially in the context of mouldy buildings and human health. However, the incorporation of low water activity (a w ) media in some culture-dependent studies revealed an abundance of xerophilic fungi indoors ( Udagawa, 1994 , Beguin, 1995 , Takahashi, 1997 , Takatori et al., 2001 , Micheluz et al., 2015 , Hirooka et al., 2016 , Rocchi et al., 2017 , Visagie et al., 2017 ). Although scant, culture-independent studies incorporating species-rank resolution also corroborate observations on the abundance of known xerophiles in the built environment ( Amend et al., 2010 , Nonnenmann et al., 2012 , Adams et al., 2013a ).…”

A new family and genus in Dothideales for Aureobasidium-like species isolated from house dust

“…2015 , Nguyen et al . 2015 ), Spiromastix, Pseudospiromastix, Sigleria ( Hirooka et al . 2016 ), and Myrmecridium ( Crous et al 2016 ).…”

Fungal Planet description sheets: 558–624

“… Sigler et al (2013) investigated taxonomic position of the strain UAMH 3124 and classified it as an undetermined fungus at generic as well as species level, which belonged to the phylogenetic lineage of Arachnotheca glomerata . We used the LSU sequence dataset of onygenalean fungi published by Hirooka et al (2016) to assess the phylogenetic position of M. cremea (data not shown). The fungus was resolved as a member of the family Onygenaceae and clustered with members of the ‘ Onygenaceae 3’ clade together with Arachnotheca glomerata UAMH 3551 (NR_111884) with 94 % sequence similarity (553/591).…”