Hannaella phyllophila sp. nov., a basidiomycetous yeast species associated with plants in Thailand and Taiwan.

Five strains representing one novel anamorphic yeast species were isolated from plant leaves collected in Thailand (strains DMKU-SP186(T), ST-111 and ST-201) and Taiwan (strains FN20L02 and SM13L16). On the basis of morphological, biochemical, physiological and chemotaxonomic characteristics and sequence analysis of the D1/D2 region of the large subunit (LSU) rRNA gene and the internal transcribed spacer (ITS) region, they were assigned to a single novel species of the genus Hannaella. The sequences of the D1/D2 regions of the LSU rRNA genes of four of the strains (DMKU-SP186(T), ST-111, FN20L02 and SM13L16) were identical, while differing from strain ST-201 by 2 substitutions and 2 gaps. The nucleotide sequence of the ITS regions of the five strains differed from each other by between 0 and 3 nucleotide substitutions. The novel species was most closely related to Hannaella luteola, but showed 1.0-1.3% nucleotide substitutions (between 6 substitutions out of 568-606 nt and 8 substitutions, and 2 gaps out of 597 nt) in the D1/D2 region of the LSU rRNA gene and 1.4-2.0% nucleotide substitutions (6-9 substitutions out of 435 nt) in the ITS region. Ballistospores were produced by three of the strains on cornmeal agar at 15 and 20 °C after 4 weeks, while H. luteola did not produce ballistospores. The name Hannaella phyllophila sp. nov. is proposed. The type strain is DMKU-SP186(T) ( = BCC 69500(T) = NBRC 110428(T) = CBS 13921(T)).

Hannaella pagnoccae sp. nov., a tremellaceous yeast species isolated from plants and soil.

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 BI118(T) ( = CBS 11142(T) = ATCC MYA-4530(T)).

Wickerhamomyces tratensis sp. nov. and Candida namnaoensis sp. nov., two novel ascomycetous yeast species in the Wickerhamomyces clade found in Thailand.

Two closely related yeast strains, ST-382 and ST-392, isolated in Thailand showed intermediate relatedness in the DNA-DNA hybridization experiment suggesting that the two strains represent closely related distinct species. In the tree based on the D1/D2 domain sequences of the large subunit rRNA gene, the two strains are located in a subclade in the Wickerhamomyces clade with high bootstrap support. In the D1/D2 domain, the two strains differed by two nucleotides and are assumed to be very closely related. Strain ST-392(T) (=BCC 15102(T) = NBRC 107799(T) = CBS 12176(T) forming hat-shaped ascospores is described as Wickerhamomyces tratensis sp. nov. and strain ST-382(T) (= BCC 15093(T) = NBRC 107800(T) = CBS 12175(T) is described as Candida namnaoensis sp. nov. because ascospores are not found in this strain. In phenotypic characteristics, W. tratensis and C. namnaoensis are discriminated by the ability of alcoholic fermentation and the assimilation of galactose, D-xylose and D-gluconic acid.

Candida sirachaensis sp. nov. and Candida sakaeoensis sp. nov. two anamorphic yeast species from phylloplane in Thailand.

Three strains (LM008(T), LM068 and LM078(T)), representing two novel yeast species were isolated from the phylloplane of three plant species by an enrichment technique. On the basis of morphological, biochemical, physiological and chemotaxonomic characteristics, and the sequence analysis of the D1/D2 domain of the large subunit rRNA gene and the internal spacer region, the three strains were assigned as two novel Candida species. Strain LM008(T) was assigned to be Candida sirachaensis sp. nov. (type strain LM008(T) = BCC 47628(T) = NBRC 108605(T) CBS 12094(T)) in the Starmerella clade. Two strains (LM068 and LM078(T)) represent a single species in the Lodderomyces-Spathaspora clade for which the name Candida sakaeoensis sp. nov. is proposed with the type strain LM078(T) = BCC 47632(T) = NBRC 108895(T) = CBS 12318(T).

Candida wangnamkhiaoensis sp. nov., an anamorphic yeast species in the Hyphopichia clade isolated in Thailand.

Two strains representing a single novel yeast species were isolated from a flower of Calycoopteris floribunda Lame (SK170(T)) and insect frass (ST-122) collected in Thailand. On the basis of morphological, biochemical, physiological and chemotaxonomic characteristics, and the sequence analysis of the D1/D2 domain of the large subunit rRNA gene and the internal transcribed spacer region, the two strains were assigned as a single novel Candida species in the Hyphopichia clade for which the name Candida wangnamkhiaoensis sp. nov. is proposed. The type strain is SK170(T)=BCC 39604(T)=NBRC 106724(T)=CBS 11695(T)).

Four novel species of the anamorphic yeast genus Candida found in Thailand and Taiwan.

Four strains of yeasts isolated in Thailand and Taiwan were found to represent four distinct novel species of the ascomycetous anamorphic yeast genus Candida. These strains are located in the Clavispora-Metschnikowia clade in a phylogenetic tree based on the D1/D2 domain sequences of the large subunit rRNA genes. Together with Candida picinguabensis and Candida saopaulonensis, the four novel species constitute a well-separated subclade from other species of the Clavispora-Metschnikowia clade. Three species from Thailand are described as Candida bambusicola sp. nov. (type strain, ST-50(T) = BCC 7750(T) = NBRC 106734(T) = CBS 11723(T)), Candida nongkhaiensis sp. nov. (type strain, ST-95(T) = BCC 8331(T) = NBRC 105874(T) =CBS 11724(T)) and Candida succicola sp. nov. (type strain, ST-631(T) = BCC 15314(T) = NBRC 106736(T) = CBS 11726(T)), respectively, and the species from Taiwan is described as Candida touchengensis sp. nov. (type strain, SY4S03(T) = NBRC 102647(T) = BCRC 23097(T) = CBS 10585(T)).

Three novel species of the anamorphic yeast genus Candida in the Candida intermedia clade found in Japan, Thailand and Taiwan.

Four strains of yeasts isolated in Japan, Thailand and Taiwan were found to represent three novel species of the genus Candida. The three species are located in a clade including Candida tsuchiyae, Candida thailandica and Candida akabanensis in a tree based on the D1/D2 domain sequences of the large subunit rRNA genes but clearly differentiated from these relative species. Three novel species are proposed for these strains, i. e., Candida berkhoutiae sp. nov., for strains ST-49(T) (=BCC 7749(T)=NBRC 106733(T)=CBS 11722(T)) isolated from insect frass in Thailand and SA13S01 (=NBRC 106053) isolated from soil in Taiwan, Candida ezoensis sp. nov., for strain Y07-1601-2(T) (=NBRC 105019(T)=CBS 11753(T)) isolated from forest soil in Japan, and Candida inulinophila sp. nov., for ST-369(T) (=BCC 15081(T)=NBRC 106735(T)=CBS 11725(T)) isolated from an unidentified wild mushroom from Thailand.

Candida uthaithanina sp. nov., an anamorphic yeast species in Nakaseomyces clade isolated in Thailand.

Three yeast stains were isolated from two unknown fruits (strains DD2-22-1(T) and SK44) and moss (strain ST-449) in Thailand. Analysis of the D1/D2 domain of the large subunit (LSU) rRNA gene sequences of the three strains revealed that they belonged to the same species. In terms of pairwise sequence similarity, Candida cf. glabrata UWO(PS) 98-110.4 and Candida nivariensis were the closest undescribed and recognized taxa, but the levels of nucleotide substitutions were 1.7-1.9% and 2.0-2.2%, respectively. The levels of nucleotide substitutions were sufficient to justify the description of a separate species of Candida. In the phylogenetic tree based on the D1/D2 domain of the LSU rRNA gene the three strains were placed in a separate branch in the Nakaseomyces clade with C. cf. glabrata UWO(PS)98-110.4, C. nivariensis, Candida glabrata, Candida bracarensis, Candida kungkrabaensis and Nakaseomyces delphensis. Phenotypic characteristics of the three strains were similar which included proliferation by multilateral budding, absence of ascospores, arthrospores or ballistospores; negative for Diazonium blue B and urease tests. The major ubiquinone was Q-6. On the basis of the above findings, the three strains were assigned to a single novel species of Candida, for which the name Candida uthaithanina sp. nov is proposed. The type strain is DD2-22-1(T) (= BCC 29899(T) = NBRC 104876(T) = CBS 10932(T)).

Proposal of Mingxiaea gen. nov. for the anamorphic basidiomycetous yeast species in the Bulleribasidium clade (Tremellales) based on molecular phylogenetic analysis, with six new combinations and four novel species.

The distinction and monophyletic property of the basidiomycetous yeast species in the Bulleribasidium clade of the order Tremellales was resolved by molecular phylogenetic analysis based on the combined sequences of the 18S rRNA gene, internal transcribed spacer (ITS) region including 5.8S rRNA gene and 26S rRNA gene D1/D2 domain. The addition to the clade of new anamorphic species identified among ballistoconidium-forming yeasts isolated from China confirmed and strengthened the separation of this clade from other clades or lineages in the order Tremellales. A new anamorphic genus, Mingxiaea gen. nov. (type species Mingxiaea variabilis comb. nov.) is therefore proposed to accommodate the anamorphic species in the Bulleribasidium clade. Six new combinations are proposed for the described species of this clade which were formerly assigned to the genus Bullera. Four novel species in the new genus were identified among 16 ballistoconidium-forming yeast strains isolated from plant leaves collected in Hainan province, southern China, by D1/D2 and ITS sequence analyses. The novel species are described as Mingxiaea sanyaensis sp. nov. (type strain SY-3.23(T) =AS 2. 3623(T) =CBS 11408(T)), Mingxiaea hainanensis (type strain WZS-8.13(T) =AS 2.4161(T) =CBS 11409(T)), Mingxiaea foliicola (type strain WZS-8.14(T) =AS 2.3518(T) =CBS 11407(T)) and Mingxiaea wuzhishanensis (type strain WZS-29.8(T) =AS 2.4163(T) =CBS 11411(T)).

Candida xylanilytica sp. nov., a xylan-degrading yeast species isolated from Thailand.

Xylan is a major component of hemicellulose, which constitutes about 40 % of plant biomass. Hydrolysis of xylan into simple sugars is one of the important steps in the conversion of lignocellulosic material to value-added products. During an investigation of cellulose- and xylan-degrading yeasts, two yeast strains that were able to use cellulose and xylan as sole carbon source were found to represent a phylogenetically distinct species in the Spathaspora clade. The closest species in terms of pairwise sequence similarity in the D1/D2 domain of the LSU rRNA gene was Candida subhashii. The novel species can be distinguished from the other species in the Spathaspora clade based on the ability to assimilate methanol and raffinose, growth in medium containing 60 % glucose, and growth at 42 °C. It ferments glucose but not other carbohydrates. The name Candida xylanilytica sp. nov. is proposed for this species. The type strain is KU-Xn11(T) ( = NBRC 106499(T)  = BCC 34694(T)  = CBS 11761(T)).

Pichia porticicola sp. nov., a novel ascomycetous yeast related to Pichia acaciae isolated from galleries of ambrosia beetles in Japan.

Eleven strains of yeasts, isolated from galleries of ambrosia beetles in Japan, formerly identified as Pichia acaciae were found to have different sequences in the D1/D2 domain of the large subunit (LSU) rRNA gene. After detailed taxonomic studies including a DNA-DNA reassociation experiment, 11 strains were found to represent a novel species of the genus Pichia. It is described as Pichia porticicola sp. nov. (type strain NBRC 100302(T) = CBS 11715(T)). The eleven strains were isolated from various samples associated with different kinds of insects and trees which were collected in 11 prefectures, from the north to the south of Japan. This species might be a common species in galleries of ambrosia beetles in Japan.

Candida potacharoeniae sp. nov. and Candida spenceri sp. nov., two novel galactose-containing ascomycetous anamorphic yeast species isolated in Thailand.

Fifteen strains of anamorphic yeasts isolated from various natural substrates collected in various places in Thailand were found to represent two novel species of anamorphic yeast genus Candida based on the sequence analysis of the D1/D2 domain of the large subunit rRNA genes, chemotaxonomic and conventional properties used for the classification of yeasts. These strains are located in the clade including Candida etchellsii and Candida magnoliae. Fourteen strains represented by ST-490(T) (BCC 15176(T)=NBRC 106439(T)= CBS 11674(T)) are closely related to Candida sorbosivorans in the D1/D2 sequences but 11 nucleotides (2.4%) were substituted. The remaining strain, ST-594(T) (=BCC 15278(T)=NBRC 106446(T)=CBS 11673(T)) showed a close relationship to Candida geochares but 21 nucleotides (4.7%) were substituted. Apparently, these strains represent two novel Candida species of the Starmerella clade. The two species are described as Candida potacharoeniae sp. nov. and Candida spenceri sp. nov. in the present paper. Like the most species of this clade, the two species contain galactose in the cells in addition to glucose and mannose and have high mol% G + C of 54.4-55.9 and 54.9, respectively.

Candida asiatica sp. nov., an anamorphic ascomycetous yeast species isolated from natural samples from Thailand, Taiwan, and Japan.

Six yeast strains of a novel anamorphic yeast species were isolated from natural samples collected in Thailand (RV60(T) and LYSM9), Taiwan (SC5L04 and GE19S05), and Japan (JCM 11058 and JCM 11059). Analysis of the D1/D2 domain of the large subunit rRNA gene sequences revealed that the sequences of five strains (LYSM9, SC5L04, GE19S05, JCM 11058, and JCM 11059) were identical and differed from the sequence of strain RV60(T) by only one nucleotide substitution. The closest recognized species in terms of pairwise sequence similarity was Candida abiesophila, but the level of nucleotide substitution (14.2-14.3%) was sufficient to justify the description of a separate species. Phenotypic characteristics of the six strains were almost the same except for two strains from Japan, which showed the ability to ferment glucose and grew in the presence of 10% NaCl and 5% glucose while the others did not. The phenotypic characteristics of the six strains included proliferation by multilateral budding, absence of ascospores, arthrospores, and ballistospores, and negative Diazonium blue B and urease tests. The major ubiquinone was Q-7. On the basis of the above findings, the six strains were assigned to a single novel species of Candida, for which the name Candida asiatica sp. nov. is proposed. The type strain is RV60(T) (BCC 25966(T) = NBRC 103863(T) = CBS 10863(T)).

Vanderwaltozyma tropicalis sp. nov., a novel ascomycetous yeast species found in Thailand.

Two strains of yeasts isolated in Thailand were found to represent a novel species of the genus Vanderwaltozyma. These strains are close to V. verrucispora but differ by 13 nucleotides (2.3%) in the D1/D2 domain of the LSU rRNA gene. This difference clearly suggests that the two strains represent a distinct species. It is described as Vanderwaltozyma tropicalis sp. nov. Vanderwaltozyma tropicalis is distinguished from V. verrucispora by the assimilation of trehalose, inability to grow in 0.1% cycloheximide and by higher maximum growth temperature.

A new Barnettozyma species forming hat-shaped ascospores isolated from soil in Japan.

In the course of a study on yeast diversity in Japan, we isolated 331 yeast strains from natural substrates in Rishiri Island, which belongs to the subarctic zone. Among the isolates from soil, two strains produced hat-shaped ascorspores and showed that reproduction occurred by conjugation of a larger cell and a smaller one. We surveyed strains preserved in our culture collection, NBRC, and found one Barnettozyma strain; thus we examined these three strains. A phylogenetic tree based on the D1/D2 domain of 26S rDNA (D1/D2) shows that these strains are included in the Barnettozyma clade, but clearly separated from the known Barnettozyma and Candida species within the clade. This group is distinguishable from B. vustinii by the ability to assimilate sucrose and maltose, and from B. populi by the ability to ferment glucose and to assimilate L-sorbose, sucrose, maltose, α-methyl-D-glucoside, and salicin. We propose that the group represent a new species, B. sucrosica sp. nov. (NBRC 105021(T)=CBS 11512(T), Mycobank no. MB515733).

Candida golubevii sp. nov., an asexual yeast related to Metschnikowia lunata.

Two strains of a novel yeast species were isolated from insect frass and a flower in Thailand and Brazil, respectively. The strain from Thailand was isolated from insect frass collected in Than-Tong waterfall, Nong Khai Province, whereas the strain from Brazil was recovered from a flower of Ipomoea sp. collected on the banks of the Paraguai River in the state of Mato Grosso do Sul. The sequences of the D1/D2 domains of the large subunit of the rDNA of both strains were identical. This novel species belonged to the Metschnikowia clade and was related to Metschnikowia lunata. No signs of sporulation were observed for the two strains on various culture media. The novel species, Candida golubevii sp. nov., is proposed to accommodate these isolates. The type strain is BCC 8332(T) (=CBS 11362(T)=NBRC 105679(T)).