Da Vinci's yeast: Blastobotrys davincii f.a., sp. nov

A new species of the yeast genus Blastobotrys was discovered during a worldwide survey of culturable xerophilic fungi in house dust. Several culture-dependent and independent studies from around the world detected the same species from a wide range of substrates including indoor air, cave wall paintings, bats, mummies, and the iconic self-portrait of Leonardo da Vinci from ca 1512. However, none of these studies identified their strains, clones, or OTUs as Blastobotrys. We introduce the new species as Blastobotrys davincii f.a., sp. nov. (holotype CBS H-24879) and delineate it from other species using morphological, phylogenetic, and physiological characters. The new species of asexually (anamorphic) budding yeast is classified in Trichomonascaceae and forms a clade along with its associated sexual state genus Trichomonascus. Despite the decade-old requirement to use a single generic name for fungi, both names are still used. Selection of the preferred name awaits a formal nomenclatural proposal. We present arguments for adopting Blastobotrys over Trichomonascus and introduce four new combinations as Blastobotrys allociferrii (equivalent to Candida allociferrii), B. fungorum (equivalent to Sporothrix fungorum), B. mucifer (equivalent to Candida mucifera), and Blastobotrys vanleenenianus (equivalent to Trichomonascus vanleenenianus). We provide a nomenclatural review and an accepted species list for the 37 accepted species in the Blastobotrys/Trichomonascus clade. Finally, we discuss the identity of the DNA clones detected on the da Vinci portrait, and the importance of using appropriate media to isolate xerophilic or halophilic fungi.

Automated summary

A new species of the yeast genus Blastobotrys was discovered in house dust, with similar species detected globally in various substrates. The new species, Blastobotrys davincii, was classified based on morphological, phylogenetic, and physiological characters. The preferred name for the new species is still under debate, but Blastobotrys is argued to be more suitable than Trichomonascus. A nomenclatural review and accepted species list for Blastobotrys/Trichomonascus clade were also provided.