Nearly 500 basidiomycetous yeast species were accepted in the latest edition of The Yeasts: A Taxonomic Study published in 2011. However, this number presents only the tip of the iceberg of yeast ...species diversity in nature. Possibly more than 99 % of yeast species, as is true for many groups of fungi, are yet unknown and await discovery. Over the past two decades nearly 200 unidentified isolates were obtained during a series of environmental surveys of yeasts in phyllosphere and soils, mainly from China. Among these isolates, 107 new species were identified based on the phylogenetic analyses of nuclear ribosomal DNA (rDNA) D1/D2 domains of the large subunit (LSU), the small subunit (SSU), and the internal transcribed spacer region including the 5.8S rDNA (ITS) and protein-coding genes both subunits of DNA polymerase II (RPB1 and RPB2), the translation elongation factor 1-α (TEF1) and the mitochondrial gene cytochrome b (CYTB), and physiological comparisons. Forty-six of these belong to 16 genera in the Tremellomycetes (Agaricomycotina). The other 61 are distributed in 26 genera in the Pucciniomycotina. Here we circumscribe eight new genera, three new families and two new orders based on the multi-locus phylogenetic analyses combined with the clustering optimisation analysis and the predicted similarity thresholds for yeasts and filamentous fungal delimitation at genus and higher ranks. Additionally, as a result of these analyses, three new combinations are proposed and 66 taxa are validated.
Full text
Available for:
GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
B Fungsin, M Hamamoto, V Arunpairojana, J Sukhumavasi, P Atthasampunna and T Nakase
Japan Collection of Microorganisms, RIKEN, Wako, Saitama 351--0198, Japan
Ten strains which were characterized by ...the formation of ballistoconidia,
the absence of xylose in whole-cell hydrolysates, the presence of Q-9 as
the major ubiquinone isoprenologue, the inability to ferment sugars and
positive diazonium blue B and urease reactions were isolated from plant
samples collected in Thailand. These isolates were closely related to
Bensingtonia phyllada based on the analysis of 18S rDNA sequences. On the
basis of the morphological, physiological and chemotaxonomic properties,
the 10 isolates were assigned to the genus Bensingtonia. DNA
complementarity showed that these isolates were genetically distinct from
known species of the genus Bensingtonia. The isolates are described as
Bensingtonia thailandica sp. nov. The type strain is strain TY-138(T) (=JCM
10651(T)).
Seven strains of ballistoconidiogenous yeasts that contain xylose, form Q-10 ubiquinone, propagate by budding and don't produce stalk conidia were isolated from plant leaves collected in Thailand and ...were found to represent two new species. The taxonomic properties of the two species coincided with the genus Bullera so they are described as Bullera koratensis sp. nov. and Bullera lagerstroemiae sp. nov. In phylogenetic trees based on the nucleotide sequences of 18S ribosomal DNA and the D1/D2 domain of 26S rDNA, these two species are located in the Trichosporonales clade (Cryptococcus humicola-Trichosporon lineage).
One hundred and thirty-six strains of ballistoconidium-forming yeasts were isolated from 54 plant samples collected in Thailand in 1987 and 1990. They were identified as 21 species in the genera ...Bensingtonia Bullera, Kockovaella, Sporidiobolus, Sporobolomyces, and Tilletiopsis. Twelve of them were found to represent hitherto undescribed species. Strains assigned to undescribed species occupied 22.8% of the isolates. Only 8 species, including 2 new ones, were commonly isolated in 1987 and 1990. This clearly suggests that many undescribed ballistoconidium-forming yeasts are living in the phyllosphere of Thailand. In the isolation study in 1987, yeasts were isolated at 23 deg C and 30 deg C and identified as 16 species. The number of isolated species was higher at 23 deg C than at 30 deg C, i.e., 12 at 23 deg C and 8 at 30 deg C, though Thailand is located in the tropical region, and the atmospheric temperature was more than 35 deg C in the daytime, and 24 deg C was the minimum from midnight to dawn, during the period of collection of plant materials from which yeasts were isolated.
Several independent surveys of yeasts associated with different plant materials and soil led to the proposal of a novel yeast species belonging to the Tremellales clade (Agaricomycotina, ...Basidiomycota). Analysis of the sequences of the D1/D2 domains and internal transcribed spacer region of the large subunit of the rRNA gene suggested affinity to a phylogenetic lineage that includes Hannaella coprosmaensis, Hannaella oryzae and Hannaella sinensis. Thirty-two isolates were obtained from different sources, including bromeliads, nectar of Heliconia psittacorum (Heliconiaceae), flowers of Pimenta dioica (Myrtaceae), roots and leaves of sugar cane (Saccharum spp.) in Brazil, leaves of Cratoxylum maingayi, Arundinaria pusilla and Vitis vinifera in Thailand, soil samples in Taiwan, and prairie soil in the USA. Sequence analysis of the D1/D2 domains of the large subunit of the rRNA gene showed that the novel species differs from Hannaella coprosmaensis and Hannaella oryzae by 36 and 46 nt substitutions, respectively. A novel species is suggested to accommodate these isolates, for which the name Hannaella pagnoccae sp. nov. is proposed. The type strain is BI118T ( = CBS 11142T = ATCC MYA-4530T).
PDF
