Dénes Dlauchy

Bandoniozyma gen. nov., a Genus of Fermentative and Non-Fermentative Tremellaceous Yeast Species

Background Independent surveys across the globe led to the proposal of a new basidiomycetous yeast genus within the Bulleromyces clade of the Tremellales, Bandoniozyma gen. nov., with seven new species. Methodology/Principal Findings The species were characterized by multiple methods, including the analysis of D1/D2 and ITS nucleotide sequences, and morphological and physiological/biochemical traits. Most species can ferment glucose, which is an unusual trait among basidiomycetous yeasts. Conclusions/Significance In this study we propose the new yeast genus Bandoniozyma, with seven species Bandoniozyma noutii sp. nov. (type species of genus; CBS 8364T u200a=u200a DBVPG 4489T), Bandoniozyma aquatica sp. nov. (UFMG-DH4.20T u200a=u200a CBS 12527T u200a=u200a ATCC MYA-4876T), Bandoniozyma complexa sp. nov. (CBS 11570T u200a=u200a ATCC MYA-4603T u200a=u200a MA28aT), Bandoniozyma fermentans sp. nov. (CBS 12399T u200a=u200a NU7M71T u200a=u200a BCRC 23267T), Bandoniozyma glucofermentans sp. nov. (CBS 10381T u200a=u200a NRRL Y-48076T u200a=u200a ATCC MYA-4760T u200a=u200a BG 02-7-15-015A-1-1T), Bandoniozyma tunnelae sp. nov. (CBS 8024T u200a=u200a DBVPG 7000T), and Bandoniozyma visegradensis sp. nov. (CBS 12505T u200a=u200a NRRL Y-48783T u200a=u200a NCAIM Y.01952T).

Candida ogatae sp. nov., an anamorphic member of the Kuraishia clade

Three methanol-assimilating yeast strains representing a hitherto undescribed species were isolated from rotten wood and freshwater samples collected in Hungary. Analysis of the D1/D2 large subunit rRNA gene sequences placed the strains in the Kuraishia clade; however, no ascospore formation was observed. These strains differ from Candida hungarica, the genetically most closely related recognized species, by four and five substitutions in D1/D2 and by >1% and 4% differences in the internal transcribed spacer and in the mitochondrial small subunit rRNA gene regions, respectively. Some phenotypic differences were also observed. Candida ogatae, a novel yeast species, is proposed to accommodate these isolates. The type culture is NCAIM Y.01845(T) (CBS 10924, NRRL Y-48474).

Spencermartinsiella europaea gen. nov., sp. nov., a new member of the family Trichomonascaceae

Ten strains of a novel heterothallic yeast species were isolated from rotten wood collected at different locations in Hungary. Analysis of gene sequences for the D1/D2 domain of the large subunit rRNA, as well as analysis of concatenated gene sequences for the nearly complete nuclear large subunit rRNA, nuclear small subunit rRNA and translation elongation factor 1-α, placed the novel species in the family Trichomonascaceae, but showed that it was distinct from all currently recognized genera. The name Spencermartinsiella europaea gen. nov., sp. nov. is proposed to accommodate the new genus and novel species. The novel species could be distinguished from recognized species of neighbouring genera on the basis of standard phenotypic characteristics. The type and isotype strains of Spencermartinsiella europaea are NCAIM Y.01817(T) (u200a=u200aNRRL Y-48265(T)u200a=u200a CBS 11730(T)) and NCAIM Y.01819(I) (u200a=u200aNRRL Y-48266(I)u200a=u200aCBS 11731(I)), respectively.

Ogataea allantospora sp. nov., an ascomycetous yeast species from phylloplane

Following a two-step enrichment in methanol containing broth, methylotrophic yeast strains were isolated from about 45% of the leaf samples collected from broad leafed deciduous trees and from herbs in Hungary. During the enrichment process protists predating the yeasts were observed. Based on standard phenotypical tests and the D1/D2 domain sequences of the large subunit (26S) rDNA of the yeast strains recovered from the phylloplane, some of them represent previously unknown species. The description of a new methylotrophic yeast species, Ogataea allantospora [type strain: NCAIM Y.01822T (CBS 10576, NRRL Y-48267)], isolated from phylloplane is given. The proposed new species is the first member of the genus which forms allantoid ascospores, therefore the emendation of the diagnosis of the genus Ogataea Yamada, Maeda & Mikata is proposed.

Yarrowia porcina sp. nov. and Yarrowia bubula f.a. sp. nov., two yeast species from meat and river sediment

Eleven yeast strains representing two hitherto undescribed species were isolated from different kinds of meat samples in Hungary and one from the sediment of a tropical freshwater river in Southeastern Brazil. The analysis of the sequences of their large subunit rRNA gene D1/D2 domain and the internal transcribed spacer (ITS) regions placed the two new species in the Yarrowia clade. Some of the seven strains representing the first new species can mate and give rise to asci and form ascospores embedded in capsular material, which qualifies it as the third teleomorph species of the Yarrowia clade. The name Yarrowia porcina sp. nov. (type strain: NCAIM Y.02100Txa0=xa0CBS 12935Txa0=xa0NRRL Y-63669T, allotype strain UFMG-RD131Axa0=xa0CBS 12932A) is proposed for this new yeast species, which, based on physiological characters, is indistinguishable from Yarrowia lipolytica and some other species of the genus. Considerable intraspecific variability was detected among the sequences of the large subunit rRNA gene D1/D2 domains of the seven strains. The variability among the D1/D2 sequences exceeded the divergence observed among the ITS sequences and in some cases more than 1xa0% substitution among the D1/D2 sequences was detected. The conspecificity of these strains was supported by the low (0–3 substitutions) sequence divergence among their ITS sequences, the result of a parsimony network analysis utilizing the concatenated ITS and D1/D2 sequences and also by the fingerprint patterns generated by microsatellite primed PCR. No ascospore formation was observed in the group of the other five strains representing the second new species. These strains shared identical D1/D2 and ITS sequences. Yarrowia bubula f.a., sp. nov. (type strain: NCAIM Y.01998Txa0=xa0CBS 12934Txa0=xa0NRRL Y-63668T) is proposed to accommodate these strains.

Yarrowia divulgata f.a., sp. nov., a yeast species from animal-related and marine sources

Five yeast strains, phenotypically indistinguishable from Yarrowia lipolytica and Yarrowia deformans, were recovered from different animal-related samples. One strain was isolated from a bacon processing plant in Denmark, two strains from chicken liver in the USA, one strain from chicken breast in Hungary and one from minced beef in Hungary. Comparisons of the sequences of their large subunit rRNA gene D1/D2 domain and the internal transcribed spacer (ITS) regions revealed that, despite their phenotypic similarity, they represent a novel yeast species of the Yarrowia clade with Y. deformans being the genotypically closest relative (LSU rRNA gene D1/D2 and ITS region similarity of 97.0 and 93.7u200a%, respectively). Yarrowia divulgata f.a., sp. nov. is proposed to accommodate these strains with F6-17(T) (u200a=u200aCBS 11013(T)u200a=u200aCCUG 56725(T)) as the type strain. Some D1/D2 sequences of yeasts from marine habitats were found in the GenBank database that were identical to those of the strains of Y. divulgata f.a., sp. nov. Unfortunately, these strains were not available for our study.

Ogataea nitratoaversa sp. nov., a methylotrophic yeast species from temperate forest habitats

Three methanol-assimilating, nitrate-negative yeast strains representing a hitherto undescribed species, were isolated from leaf and rotten wood samples collected in temperate forests in Hungary. Analysis of the D1/D2 large subunit ribosomal RNA gene sequences placed the strains in the Ogataea clade. The three strains share identical D1/D2 and ITS sequences and significantly differ from the genetically most closely related species, Pichia pilisensis. Five substitutions in D1/D2 and more than 10% difference in the ITS regions were detected. A novel yeast species, Ogataea nitratoaversa, is proposed to accommodate these isolates. The type culture is NCAIM Y.01837T (CBS 10796, NRRL Y-48449). As the current description of the genus does not allow the inclusion of nitrate negative species, the emendation of the diagnosis of the genus Ogataea Yamada, Maeda and Mikata is proposed.

Ogataea populialbae sp. nov., a yeast species from white poplar

During a survey of methylotrophic yeasts in natural habitats in Hungary, the yeast community associated with the exudates of white poplar (Populus alba) was found to be unique among the tree exudates hitherto investigated. Nineteen methanol-assimilating yeast strains representing an undescribed ascomycetous species were isolated from tree exudates of P. alba collected at different locations in Hungary. Analysis of the D1/D2 large subunit rRNA gene sequences placed the strains in the Ogataea clade and the new species is described as Ogataea populialbae. The type culture is NCAIM Y.01853(T) (CBS 11363, NRRL Y-48632).

Zygosaccharomyces favi sp. nov., an obligate osmophilic yeast species from bee bread and honey

Five yeast strains representing a hitherto undescribed yeast species were isolated from bee bread and honey in Hungary. They are obligate osmophilic, i.e. they are unable to grow in/on high water activity culture media. Following isogamous conjugation, they form 1–4 spheroid or subspheroid ascospores in persistent asci. The analysis of the sequences of their large subunit rRNA gene D1/D2 domain placed the new species in the Zygosaccharomyces clade. In terms of pairwise sequence similarity, Zygosaccharomyces gambellarensis is the most closely related species. Comparisons of D1/D2, internal transcribed spacer and translation elongation factor-1α (EF-1α) gene sequences of the five strains with that of the type strain of Z. gambellarensis revealed that they represent a new yeast species. The name Zygosaccharomyces favi sp. nov. (type strain: NCAIM Y.01994Txa0=xa0CBS 13653Txa0=xa0NRRL Y-63719Txa0=xa0ZIM 2551T) is proposed for this new yeast species, which based on phenotype can be distinguished from related Zygosaccharomyces species by its obligate osmophilic nature. Some intragenomic sequence variability, mainly indels, was detected among the ITS copies of the strains of the new species.

Ogataea kolombanensis sp. nov., Ogataea histrianica sp. nov. and Ogataea deakii sp. nov., three novel yeast species from plant sources

Nine methanol-assimilating yeast strains isolated from olive oil sediments in Slovenia, extra virgin olive oil from Italy and rotten wood collected in Hungary were found to form three genetically separated groups, distinct from the currently recognized yeast species. Sequence analysis from genes of the small subunit (SSU) rRNA, internal transcribed spacer region/5.8S rRNA, large subunit (LSU) rRNA D1/D2 domains and translational elongation factor-1α (EF-1α) revealed that the three closely related groups represent three different undescribed yeast species. Sequence analysis of the LSU rRNA gene D1/D2 domains placed the novel species in the Ogataea clade. The three novel species are designated as Ogataea kolombanensis sp. nov. (type strain: ZIM 2322(T) = CBS 12778(T) = NRRL Y-63657(T)), Ogataea histrianica sp. nov. (type strain: ZIM 2463(T) = CBS 12779(T) = NRRL Y-63658(T)) and Ogataea deakii sp. nov. (type strain: NCAIM Y.01896(T) = CBS 12735(T) = NRRL Y-63656(T)).