Debaryomyces singareniensis sp. nov., a novel yeast species isolated from a coal mine soil in India

Three strains (AP19, AP19-4 and AP19-6) of a novel yeast species were isolated from soil from the Singareni coal mines, Andhra Pradesh, India. They were morphologically, physiologically and phylogenetically identical and produced one to four spherical ascospores per ascus. Phylogenetic analysis using the D1/D2 variable domain of the large-subunit rRNA gene indicated that the closest relative of these strains is Debaryomyces etchellsii (2.6% divergence). Other species related to these strains are D. mycophilus (5.1% divergence) and species of the D. hansenii cluster (4.9-5.6% divergence). The novel species differs by 20 and 15 physiological tests from D. etchellsii and D. mycophilus, respectively. Phylogenetic analysis of the internal transcribed spacer (ITS) region also indicated that strains of the new species are related to D. etchellsii (7.7% divergence), followed by species of the D. hansenii cluster (9-10% divergence). In the small-subunit rRNA gene sequences, they differed from D. etchellsii by seven substitutions and one insertion or deletion of a base in a sequence (indel) and from D. mycophilus by 17 substitutions and 1 indel. The physiological, biochemical and molecular data suggest that these strains belong to a novel species, for which we propose the name Debaryomyces singareniensis sp. nov. The type strain of AP19(T) (=MTCC 7061(T)=CBS 10405(T)). The Mycobank number of the new species is MB510046.     

Torulaspora maleeae sp. nov., a novel ascomycetous yeast species from Japan and Thailand

Nine strains of a new Torulaspora species were isolated from natural samples collected in Japan and Thailand including one strain obtained from a leaf of Rhizophora stylosa (NBRC 11061T), one strain from soil (NBRC 11062), six strains from mosses (ST-14, ST-266, ST-510, ST-511, ST-513 and ST-581) and one strain from sediment in mangrove forest (RV-51). On the basis of morphological, biochemical, physiological and chemotaxonomic characteristics, and the sequence analyses of the D1/D2 domain of the large subunit (LSU) rRNA gene and the internal transcribed spacer (ITS) (ITS1-5.8S rRNA gene-ITS2) region, the nine strains were found to represent a single novel species of the genus Torulaspora, which were named Torulaspora maleeae sp. nov. The type strain is NBRC 11061T (BCC 25515T=CBS 10694T). In the phylogenetic trees based on the sequences of the D1/D2 domain of the LSU rRNA gene, T. maleeae showed a close relationship with the five recognized species of the genus Torulaspora, Torulaspora delbrueckii, Torulaspora franciscae, Torulaspora globosa, Torulaspora microellipsoides and Torulaspora pretoriensis. Torulaspora maleeae differed from the five recognized species of the genus Torulaspora by six to 12 nucleotide substitutions (1.1-2.1%) in the D1/D2 domain of the LSU rRNA gene and by 6.4-11.7% nucleotide substitutions in the ITS (ITS1-5.8S rRNA gene-ITS2) region.     

Vanderwaltozyma verrucispora sp. nov., a new ascomycetous yeast species

A new yeast species, Vanderwaltozyma verrucispora , is proposed in this study based on two strains isolated from partially decayed leaves in Japan and one strain from soil in Taiwan. The species is characterized by the fermentation of glucose and galactose, formation of one to four spheroidal to ellipsoidal ascospores with warty surfaces in each ascus, and assimilation of a few carbon and nitrogen compounds. Genus assignment and distinction of the species from the other two recognized species of Vanderwaltozyma is based on the morphological and physiological characteristics, and phylogenetic analysis of nucleotide sequences of the D1/D2 domains of the large subunit (LSU) rRNA gene. From these comparisons, the name V. verrucispora sp. nov. is proposed. Sequence analysis of the D1/D2 domains of the LSU rRNA gene reveals that the phylogenetically closest relative of V. verrucispora is Vanderwaltozyma yarrowii . The type strain of the new species, which was isolated from a partially decayed leaf in Kagoshima Prefecture, Japan, is NBRC 1884^T (=CBS 10887^T=BCRC 23141^T).     

Blastobotrys serpentis sp. nov., isolated from the intestine of a Trinket snake (Elaphe sp., Colubridae)

Asporogenus yeast strains W113AT and W113B were isolated from the intestine of a dead Trinket snake. The two isolates showed 100% sequence similarity in the D1/D2 domain of the large-subunit (LSU) rRNA gene, internal transcribed spacer (ITS) 1-5.8S rRNA gene-ITS2 region and mitochondrial small-subunit rRNA gene and the cytochrome oxidase II gene sequence and also showed similar phenotypic characteristics. The nearest phylogenetic neighbors of W113AT and W113B based on the sequence of the D1/D2 domain of the LSU rRNA gene were Blastobotrys chiropterorum NRRL Y-17017T and Blastobotrys terrestris NRRL Y-17704T with about 98% similarity. The close affiliation of W113AT and W113B with B. chiropterorum NRRL Y-17017T and B. terrestris NRRL Y-17704T was also evident from the high similarity observed in the nucleotide sequences of the mitochondrial small subunit rRNA (96-97.8%) and the cytochrome oxidase II (95.5-95.6%) genes. In the neighbor-joining phylogenetic trees constructed based on the D1/D2 domain or cytochrome oxidase gene, the isolates clustered with the above-mentioned species. However, the isolates showed a number of differences in their phenotypic properties with B. chiropterorum NRRL Y-17017T and B. terrestris NRRL Y-17704T and hence are regarded as representing a novel member of the genus Blastobotrys, for which the name Blastobotrys serpentis sp. nov. is proposed.     

Polyphasic identification of yeasts isolated from bark of cork oak during the manufacturing process of cork stoppers

A two-step protocol was used for the identification of 52 yeasts isolated from bark of cork oak at initial stages of the manufacturing process of cork stoppers. The first step in the identification was the separation of the isolates into groups by their physiological properties and RFLPs of the ITS-5.8S rRNA gene. The second step was the sequencing of the D1/D2 domains of the 26S rRNA gene of selected isolates representing the different groups. The results revealed a predominance of basidiomycetous yeasts (11 species), while only two species represented the ascomycetous yeasts. Among the basidiomycetous yeasts, members representing the species Rhodosporidium kratochvilovae and Rhodotorula nothofagi, that have been previously isolated from plant material, were the most abundant. Yeasts pertaining to the species Debaryomyces hansenii var. fabryii, Rhodotorula mucilaginosa and Trichosporon mucoides were isolated in small numbers.     

Prototheca tumulicola sp. nov., a novel achlorophyllous,yeast-like microalga isolated from the stone chamber interior of the Takamatsuzuka Tumulus

Two achlorophyllous microalgal strains were isolated from the soil and white moldy colony collected inside the stone chamber of the Takamatsuzuka Tumulus in Japan. Phylogenetic analyses of the small subunit ribosomal RNA (SSU rRNA) and Dl/D2 large subunit ribosomal RNA (LSU rRNA) gene sequences, and concatenated gene sequences of the SSU and D1/D2 LSU rRNA genes indicated that our two isolates were the members of the non-photosynthetic, yeast-like microalgal Chlorellaceous genus Prototheca (Chlorellales, Trebouxiophyceae, Chlorophyta) but well distinguished from known species. Based on phenotypic and genotypic characteristics, isolates T6713-13-10^T and T61213-7-11 are proposed to represent a novel species in Prototheca, P. tumulicola, with the type strain JCM 31123^T (isolate T6713-13-10^T).     

Candida dajiaensis sp. nov., Candida yuanshanicus sp. nov., Candida jianshihensis sp. nov., and Candida sanyiensis sp. nov., four anamorphic, ascomycetous yeast species isolated from soil in Taiwan

Nine anamorphic, ascomycetous yeast strains belonging to the Pichia anomala clade were recovered from forest soil in 2006 in Taiwan. The nine yeast strains represent four novel yeast species based on the sequences of their D1/D2 domain of the large subunit (LSU) rRNA gene and their physiological characteristics. The scientific names of Candida dajiaensis sp. nov., Candida yuanshanicus sp. nov., Candida jianshihensis sp. nov., and Candida sanyiensis sp. nov. are proposed for these novel yeast species. The type strains are C. dajiaensis SM11S03(T) (=CBS 10590(T)=BCRC 23099(T)), C. yuanshanicus SY3S02(T) (=CBS 10589(T)=BCRC 23100(T)), C. jianshihensis SM8S04(T) (=CBS 10591(T)=BCRC 23096(T)), and C. sanyiensis SA1S06(T) (=CBS 10592(T)=BCRC 23094(T)). Sequence analysis of the D1/D2 of the LSU rRNA gene revealed that the three species, C. dajiaensis, C. yuanshanicus and Pichia onychis, shared a separate branch in the phylogenetic tree, C. jianshihensis is phylogenetically related to Candida ulmi and Pichia alni, and the phylogenetically closest relative of C. sanyiensis is Pichia populi.     

Application of SSCP-PCR fingerprinting to profile the yeast community in raw milk Salers cheeses

Bacteria and yeasts are important sensory factors of raw-milk cheeses as they contribute to the sensory richness and diversity of these products. The diversity and succession of yeast populations in three traditional Registered Designation of Origin (R.D.O.) Salers cheeses have been determined by using phenotypic diagnoses and Single-Strand Conformation Polymorphism (SSCP) analysis. Isolates were identified by phenotypic tests and the sequencing of the D1-D2 domains of the 26S rRNA gene. Ninety-two percent of the isolates were identified as the same species in both tests. Yeast-specific primers were designed to amplify the V4 region of the 18S rRNA gene for SSCP analysis. The yeast species most frequently encountered in the three cheeses were Kluyveromyces lactis, Kluyveromyces marxianus, Saccharomyces cerevisiae, Candida zeylanoides and Debaryomyces hansenii. Detection of less common species, including Candida parapsilosis, Candida silvae, Candida intermedia, Candida rugosa, Saccharomyces unisporus, and Pichia guilliermondii was more efficient with the conventional method. SSCP analysis was accurate and could be used to rapidly assess the proportions and dynamics of the various species during cheese ripening. Each cheese was clearly distinguished by its own microbial community dynamics.     

Differential detection of Debaryomyces hansenii isolated from intermediate-moisture foods by PCR-RFLP of the IGS region of rDNA

The amplification by PCR of the Intergenic Spacer region (IGS) of rDNA followed by Restriction Fragment Length Polymorphism (RFLP) analysis was evaluated as a potential method for the identification of Debaryomyces hansenii among other yeast species that frequently contaminate Intermediate-Moisture Foods (IMFs). For a first rapid differentiation at the species level, the determination of the IGS-PCR fragment size was found to be a useful approach. The digestion of this region with the enzymes HhaI, HapII and MboI resulted in specific patterns that permit the identification of D. hansenii among other yeast species. This method also permitted the discrimination between the D. hansenii varieties (var. hansenii and var. fabryi) as well as the differentiation of D. hansenii from other species of the genus, such as Debaryomyces pseudopolymorphus or Debaryomyces polymorphus var. polymorphus. The IGS-PCR RFLP method was assayed for the differential detection of D. hansenii in contaminated or spoiled IMF products and compared with traditional identification procedures, resulting in a 100% detection rate for D. hansenii.     

Candida carvajalis sp. nov., an ascomycetous yeast species from the Ecuadorian Amazon jungle

In the course of a yeast biodiversity survey of different ecological habitats found in Ecuador, two yeast strains (CLQCA 20-011^T and CLQCA20-014) were isolated from samples of rotten wood and fallen leaf debris collected at separate sites in the central region of the Ecuadorian Amazonia. These strains were found to represent a novel yeast species based on the sequences of their D1/D2 domain of the large-subunit (LSU) rRNA gene and their physiological characteristics. Phylogenetic analysis based on LSU D1/D2 sequences revealed this novel species to be most closely related to Candida asparagi, Candida fructus, Candida musae and two as yet undescribed Candida species, with the six yeast taxa collectively forming a distinct species group within the Clavispora clade. The species name of Candida carvajalis sp. nov. is proposed to accommodate these strains, with CLQCA 20-011^T (NCYC 3509^T, CBS 11361^T) designated as the type strain.     

<Emphasis Type="Italic">Kazachstania wufongensis</Emphasis> sp. nov., an ascosporogenous yeast isolated from soil in Taiwan

A new yeast species, Kazachstania wufongensis, is proposed in this paper based on six strains isolated from soil in Taiwan. The species may produce one to four ellipsoidal ascospores in each ascus, directly transformed from diploid cells. Genus assignment and distinction of the species from other recognized species of Kazachstania is based on morphological and physiological characteristics, and on phylogenetic analysis of nucleotide sequences of the D1/D2 domains of the large subunit (LSU) rRNA gene. Sequence analysis of the D1/D2 domains of the LSU rRNA gene reveals that K. wufongensis is a member of the Kazachstania exigua complex, and its phylogenetically closest relatives are K. exigua, K. barnettii, K. bulderi, and K. turicensis. The species can be further differentiated from the other phylogenetically related species based on internal transcribed spacer sequence and electrophoretic karyotype. Therefore, the new species Kazachstania wufongensis sp. nov. is proposed. The type strain of this new species, which was isolated from forest soil in Wufong, Hsinchu, Taiwan, is FN21S03^T (=CBS 10886^T = BCRC 23138^T).     

Citeromyces cibodasensis sp. nov., a novel yeast species isolated from leaf litter in Indonesia

A novel yeast species was isolated from leaf litter of Macropanax dispermus obtained from the Cibodas Botanical Garden, West Java, Indonesia. The two strains of the species displayed typical characteristics of the genus Citeromyces. Phylogenetic analysis based on the gene sequences of the D1/D2 domains of large subunit (LSU) rDNA, internal transcribed spacer (ITS) including 5.8S rDNA, mitochondrial small-subunit rRNA gene (MtSm), and translation elongation factor-1α (EF-1α) showed that the novel strains were clearly separated from the other four existing species of the genus Citeromyces. Therefore, the two strains were proposed to represent a novel species within the genus Citeromyces, for which the name Citeromyces cibodasensis is proposed; the type strain is NBRC 110244^T (= CBS 14272^T?=?InaCCY703^T?=?AK 01).     

Wickerhamomyces edaphicus sp. nov. and Pichia jaroonii sp. nov., two ascomycetous yeast species isolated from forest soil in Thailand

Four yeast strains were isolated from soil in a mixed deciduous forest in Amphoe Wang Nam Khiao, Nakhon Ratchasima province, Thailand. On the basis of morphological, biochemical, physiological and chemotaxonomic characteristics, and the sequence analyses of the D1/D2 domain of the large-subunit (LSU) rRNA gene, small-subunit rRNA gene and internal transcribed spacer (ITS) region, the three strains (S-29, S-63 and S-80) were found to represent a single species of the genus Wickerhamomyces , which were named Wickerhamomyces edaphicus sp. nov. The type strain is S-29^T (BCC 21231^T=NBRC 101969^T=CBS 10408^T). Strain S-75 represented a novel species of the genus Pichia on the basis of morphological, biochemical, physiological and chemotaxonomic characteristics, and the sequence analyses of the D1/D2 domain of the LSU rRNA gene, for which the name Pichia jaroonii sp. nov. is proposed. The type strain is S-75^T (BCC 23061^T, NRBC 102180^T=CBS 10930^T).     

<Emphasis Type="Italic">Ogataea saltuana</Emphasis> sp. nov., a novel methanol-assimilating yeast species

Four ascosporulating strains of an undescribed methanol-assimilating yeast species were isolated from forest habitats in Hungary. Three were recovered from rotten wood and one from leaves of a sessile oak (Quercus petraea). An additional isolate of the undescribed species sharing similar phenotypic characters with the above-noted strains was recovered from the gut of an unidentified beetle collected from under the bark of a coniferous tree in Bulgaria. A closely related, but somewhat divergent strain was recovered from insect frass in a Ponderosa pine (Pinus ponderosa) collected in New Mexico, USA. Analysis of the D1/D2 sequences of the LSU rRNA gene placed the new species in the Ogataea clade. The ITS and the D1/D2 LSU sequences of the rRNA gene repeats were compared for the above-noted strains and that of the type strain of Ogataea zsoltii, the closest neighbour among currently recognized Ogataea species. Their relatedness was investigated by parsimony network analysis as well. As a result of the sequence analysis, it was concluded that the six strains isolated from tree associated habitats represent a single new yeast species. Ogataea saltuana sp. nov. is proposed to accommodate these strains. The type strain NCAIM Y.01833^T (CBS 10795^T, NRRL Y-48448^T) was recovered from rotten wood of Scotch pine (Pinus silvestris) in Hungary. The GenBank accession number for the D1/D2 domain nuclear large subunit rRNA gene sequence of strain NCAIM Y.01833^T (CBS 10795^T, NRRL Y-48448^T) is EU327033. The MycoBank number of the new species is MB 519966.     

我国代表地区须癣毛癣菌复合体的分子鉴定与分型研究

目的对我国代表地区的须癣毛癣菌菌株进行分子再鉴定和分型研究。方法选取我国南北方8个省市地区经表型鉴定的须癣毛癣菌菌株47株,通过再培养形态观察、生理试验;PCR扩增核糖体DNA(rDNA)的内转录间隔区(ITS)和核糖体大亚基(LSU)D1-D2区,测序后利用数据库进行序列比对,对须癣毛癣菌复合体进行再鉴定;PCR扩增rDNA非转录间隔区(NTS)的三个串联重复亚单位S0、S1和S2区,进行种内分型,并比较不同部位来源菌株型别的差异性。结果我国南北方8个省市地区47株须癣毛癣菌中3株鉴定为断发毛癣菌,6株鉴定为无性型苯海姆节皮菌,其余均鉴定为万博节皮菌中的亲人型趾间毛癣菌;三对不同引物扩增38株趾间型毛癣菌和2株苯海姆节皮菌NTS区,共产生28种特征性带型。带型和菌株来源及发生部位无相关性。结论我国分离自人类须癣毛癣菌复合体的主要组成菌种为趾间毛癣菌;ITS区结合LSU D1-D2区测序有助于鉴定须癣毛癣菌复合体至种水平;NTS区的三个串联重复亚单位所产生的特征性指纹图提供了一种快速、稳定的分子生物学种内分型方法,可应用于趾间毛癣菌感染的流行病学研究。     

Impairment of cobalt-induced riboflavin biosynthesis in a Debaryomyces hansenii mutant

Flavinogenic yeasts such as Debaryomyces hansenii overproduce riboflavin (RF) in the presence of heavy metals. Growth and RF production were compared between wild-type D. hansenii and a RF production-impaired metal-tolerant ura3 mutant in the presence of sublethal cobalt(II) concentrations. Debaryomyces hansenii (wild type) exhibits an extended lag phase with an increase in RF synthesis. Supplementation of exogenous uracil shortened the lag phase at the highest concentration of cobalt(II) used, suggesting that uracil has a possible role in metal acclimation. The D. hansenii ura3 mutant isolated by chemical mutagenesis exhibited a higher level of metal tolerance, no extended lag phase, and no marked increase in RF synthesis. Transformation of the mutant with the URA3 gene isolated from Saccharyomyces cerevisiae or D. hansenii did not restore wild-type characteristics, suggesting a second mutation that impairs RF oversynthesis. Our results demonstrate that growth, metal sensitivity, and RF biosynthesis are linked.