On the reclassification of species assigned to Candida and other anamorphic ascomycetous yeast genera based on phylogenetic circumscription

Abstract

Multigene phylogenies have been instrumental in revising the classification of ascosporic (teleomorph) yeasts in a natural system based on lines of descent. Although many taxonomic changes have already been implemented for teleomorph taxa, this is not yet the case for the large genus Candida and smaller anascosporic (anamorph) genera. In view of the recently introduced requirement that a fungal species or higher taxon be assigned only a single valid name under the new International Code of Nomenclature for algae, fungi, and plants (Melbourne Code), the current species of Candida and other anamorph yeast genera must undergo revision to make genus membership consistent with phylogenetic affinities. A review of existing data and analyses shows that certain Candida species may be assigned to teleomorph genera with high confidence using multigene phylogenies. Candida species that form well-circumscribed phylogenetic clades without any teleomorph member justify the creation of new genera. However, a considerable number of Candida species sit at the end of isolated and often long branches, and hence cannot be assigned to larger species groups. They should be maintained in Candida sensu lato until studied by multigene analyses in datasets with comprehensive taxon sampling. The principle of name stability has to be honoured to the largest extent compatible with a natural classification of Candida species.

Yamadazyma kitorensis f.a., sp. nov. and Zygoascus biomembranicola f.a., sp. nov., novel yeasts from the stone chamber interior of the Kitora tumulus, and five novel combinations in Yamadazyma and Zygoascus for species of Candida

“…In addition to proposing two novel species of the Yamadazyma and Zygoascus clades, we also propose the reassignment of the five known species Candida olivae, Candida takamatsuzukensis, Candida tumulicola, Candida polysorbophila and Candida bituminiphila to the genus Yamadazyma or Zygoascus as new combinations. Our transfer of these five species to the genera Yamadazyma and Zygoascus is consistent with the placement suggested by Daniel et al (2014). Reclassifications of other species of Candida shown in the trees may be made according to the 'one fungus5one name' principle of the current International Code of Nomenclature of Algae, Fungi, and Plants (Melbourne Code) (McNeill et al, 2012; Norvell, 2011).…”

“…Species of the C. membranifaciens clade have been suggested to be assigned to the genus Yamadazyma (Daniel et al, 2014). On the other hand, two isolates placed in the Zygoascus clade (Kurtzman & Robnett, 2007) were also found among the minority yeast isolates from both tumuli.…”

Fungal DNA barcoding

“…With the availability of rapidly expanding public sequence databases and DNA sequencing facilities, it is now possible to process a large number of samples within a week. Indeed, coupled with the development of efficient yeast species identification has been a rapid increase in the number of published new yeast species, species name revisions, and a wealth of their ecological data over the last decade (Kurtzman et al 2011;Daniel et al 2014).…”

Starmerella syriaca f.a., sp. nov., an osmotolerant yeast species isolated from flowers in Syria

“…As C. magnoliae, C. sorbosivorans and C. vaccinii had been placed in the Starmerella clade of Saccharomycotina by previous D1/D2 analyses Daniel et al 2014), the close relationship revealed among their D1/D2 sequences and that of the Syrian isolates suggested that the latter can also be assigned to this group. Because of this relationship, the name Starmerella syriaca f.a., sp.…”

“…The Starmerella clade includes yeasts predominantly isolated from bees and their environment (reviewed in Rosa et al 2003, Daniel et al 2014. As bees visit flowers, members of the clade can frequently be encountered in flowers (e.g.…”