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Candida is a polyphyletic genus of sexually reproducing yeasts in the Saccharomycotina with more than 400 species that occur in almost all families of the subclass and its name is strongly connected with the infectious disease candidiasis. During the last two decades, approximately half of the Candida species have been reassigned into more than 36 already existing genera and 14 newly proposed genera, but the polyphyletic feature of the genus largely remained. Candida auris is an important, globally emerging opportunistic pathogen that has caused life-threatening outbreaks in healthcare facilities worldwide. This species belongs to the Candida auris - Candida haemuli (CAH) clade in the Metschnikowiaceae, a clade that contains multidrug-resistant clinically relevant species, but also species isolated from natural environments. The clade is phylogenetically positioned remotely from the type species of the genus Candida that is Candida vulgaris (currently interpreted as a synonym of Candida tropicalis) and belongs to the family Debaryomycetaceae. Although previous phylogenetic and phylogenomic studies confirmed the position of C. auris in the Metschnikowiaceae, these analyses failed to resolve the position of the CAH clade within the family and its delimitation from the genera Clavispora and Metschnikowia. To resolve the position of the CAH clade, phylogenomic and comparative genomics analyses were carried out to address the phylogenetic position of C. auris and related species in the Metschnikowiaceae using several metrics, such as the average amino acid identity (AAI) values, the percentage of conserved proteins (POCP), and the presence-absence patterns of orthologs (PAPO).Based on those approaches, 13 new genera are proposed for various Candida and Hyphopichia species, including members of the CAH clade in the Metschnikowiaceae. As a result, C. auris and related species are reassigned to the genus Candidozyma. Fifty-five new combinations and nine new species are intr

A correct classification of fungi, including yeasts, is of prime importance to understand fungal biodiversity and to communicate about this diversity. Fungal genera are mainly defined based on phenotypic characteristics and the results of single or multigene-based phylogenetic analyses. However, because yeasts often have less phenotypic characters, their classification experienced a strong move towards DNA-based data, from short ribosomal sequences to multigene phylogenies and more recently to phylogenomics. Here, we explore the usefulness of various genomics-based parameters to circumscribe fungal genera more correctly taking the yeast domain as an example. Therefore, we compared the results of a phylogenomic analysis, average amino acid identity (AAI) values, the presence of conserved signature indels (CSIs), the percentage of conserved proteins (POCP) and the presence- absence patterns of orthologs (PAPO). These genome-based metrics were used to investigate their usefulness in demarcating 13 hitherto relatively well accepted genera in Saccharomycetaceae, namely Eremothecium, Grigorovia, Kazachstania, Kluyveromyces, Lachancea, Nakaseomyces, Naumovozyma, Saccharomyces, Tetrapisispora, Torulaspora, Vanderwaltozyma, Zygosaccharomyces and Zygotorulaspora. As a result, most of these genera are supported by the genomics-based metrics, but the genera Kazachstania , Nakaseomyces and Tetrapisispora were shown to be genetically highly diverse based on the above listed analyses. Considering the results obtained for the presently recognized genera, a range of 80–92% POCP values and a range of 60–70 % AAI values might be valuable thresholds to discriminate genera in Saccharomycetaceae. Furthermore, the genus-specific genes identified in the PAPO analysis and the CSIs were found to be useful as synapomorphies to characterize and define genera in Saccharomycetaceae. Our results indicate that the combined monophyly-based phylogenomic analysis together with genomic relatedness ind

The subphylum Ustilaginomycotina (Basidiomycota, Fungi) comprises mainly plant pathogenic fungi (smuts). Some of the lineages possess cultivable unicellular stages that are usually classified as yeast or yeast-like species in a largely artificial taxonomic system which is independent from and largely incompatible with that of the smut fungi. Here we performed phylogenetic analyses based on seven genes including three nuclear ribosomal RNA genes and four protein coding genes to address the molecular phylogeny of the ustilaginomycetous yeast species and their filamentous counterparts. Taxonomic revisions were proposed to reflect this phylogeny and to implement the ‘One Fungus = One Name’ principle. The results confirmed that the yeast-containing classes Malasseziomycetes, Moniliellomycetes and Ustilaginomycetes are monophyletic, whereas Exobasidiomycetes in the current sense remains paraphyletic. Four new genera, namely Dirkmeia gen. nov., Kalmanozyma gen. nov., Golubevia gen. nov. and Robbauera gen. nov. are proposed to accommodate Pseudozyma and Tilletiopsis species that are distinct from the other smut taxa and belong to clades that are separate from those containing type species of the hitherto described genera. Accordingly, new orders Golubeviales ord. nov. with Golubeviaceae fam. nov. and Robbauerales ord. nov. with Robbaueraceae fam. nov. are proposed to accommodate the sisterhood of Golubevia gen. nov. and Robbauera gen. nov. with other orders of Exobasidiomycetes. The majority of the remaining anamorphic yeast species are transferred to corresponding teleomorphic genera based on strongly supported phylogenetic affinities, resulting in the proposal of 28 new combinations. The taxonomic status of a few Pseudozyma species remains to be determined because of their uncertain phylogenetic positions. We propose to use the term pro tempore or pro tem. in abbreviation to indicate the single-species lineages that are temporarily maintained.

Families and genera assigned to Tremellomycetes have been mainly circumscribed by morphology and for the yeasts also by biochemical and physiological characteristics. This phenotype-based classification is largely in conflict with molecular phylogenetic analyses. Here a phylogenetic classification framework for the Tremellomycetes is proposed based on the results of phylogenetic analyses from a seven-genes dataset covering the majority of tremellomycetous yeasts and closely related filamentous taxa. Circumscriptions of the taxonomic units at the order, family and genus levels recognised were quantitatively assessed using the phylogenetic rank boundary optimisation (PRBO) and modified general mixed Yule coalescent (GMYC) tests. In addition, a comprehensive phylogenetic analysis on an expanded LSU rRNA (D1/D2 domains) gene sequence dataset covering as many as available teleomorphic and filamentous taxa within Tremellomycetes was performed to investigate the relationships between yeasts and filamentous taxa and to examine the stability of undersampled clades. Based on the results inferred from molecular data and morphological and physiochemical features, we propose an updated classification for the Tremellomycetes. We accept five orders, 17 families and 54 genera, including seven new families and 18 new genera. In addition, seven families and 17 genera are emended and one new species name and 185 new combinations are proposed. We propose to use the term pro tempore or pro tem. in abbreviation to indicate the species names that are temporarily maintained.

Most small genera containing yeast species in the Pucciniomycotina (Basidiomycota, Fungi) are monophyletic, whereas larger genera including Bensingtonia, Rhodosporidium, Rhodotorula, Sporidiobolus and Sporobolomyces are polyphyletic. With the implementation of the “One Fungus = One Name” nomenclatural principle these polyphyletic genera were revised. Nine genera, namely Bannoa, Cystobasidiopsis, Colacogloea, Kondoa, Erythrobasidium, Rhodotorula, Sporobolomyces, Sakaguchia and Sterigmatomyces, were emended to include anamorphic and teleomorphic species based on the results obtained by a multi-gene phylogenetic analysis, phylogenetic network analyses, branch length-based methods, as well as morphological, physiological and biochemical comparisons. A new class Spiculogloeomycetes is proposed to accommodate the order Spiculogloeales. The new families Buckleyzymaceae with Buckleyzyma gen. nov., Chrysozymaceae with Chrysozyma gen. nov., Microsporomycetaceae with Microsporomyces gen. nov., Ruineniaceae with Ruinenia gen. nov., Symmetrosporaceae with Symmetrospora gen. nov., Colacogloeaceae and Sakaguchiaceae are proposed. The new genera Bannozyma, Buckleyzyma, Fellozyma, Hamamotoa, Hasegawazyma, Jianyunia, Rhodosporidiobolus, Oberwinklerozyma, Phenoliferia, Pseudobensingtonia, Pseudohyphozyma, Sampaiozyma, Slooffia, Spencerozyma, Trigonosporomyces, Udeniozyma, Vonarxula, Yamadamyces and Yunzhangia are proposed to accommodate species segregated from the genera Bensingtonia, Rhodosporidium, Rhodotorula, Sporidiobolus and Sporobolomyces. Ballistosporomyces is emended and reintroduced to include three Sporobolomyces species of the sasicola clade. A total of 111 new combinations are proposed in this study.

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