<Emphasis Type="Italic">Saturnispora serradocipensis</Emphasis> sp. nov. and <Emphasis Type="Italic">Saturnispora gosingensis</Emphasis> sp. nov., two ascomycetous yeasts from ephemeral habitats

Two novel ascomycetous yeast species, Saturnispora serradocipensis and Saturnispora gosingensis, were isolated from leaf detritus in a tropical stream of Southeastern Brazil and a mushroom collected in Taiwan, respectively. Analysis of the D1/D2 domains of the large-subunit of the rRNA gene of these strains showed that these species are related to Saturnispora hagleri, their closest relative. Saturnispora serradocipensis and S. gosingensis differed from S. hagleri, respectively, by seven nucleotide substitutions and two indels and three nucleotide substitutions and three indels in D1/D2 rRNA sequences. The two new species differ from each another by four nucleotide substitutions and one indel in D1/D2 rRNA sequences. However, the ITS sequences of S. serradocipensis, S. gosingensis and S. hagleri were quite divergent, showing that they are genetically separate species. The type strain of S. serradocipensis is UFMG-DC-198^T (=CBS 11756^T = NRRL Y-48717^T), and of S. gosingensis GA4M05^T is (CBS 11755^T = NRRL Y-48718^T).     

<Emphasis Type="Italic">Ogataea cecidiorum</Emphasis> sp. nov., a methanol-assimilating yeast isolated from galls on willow leaves

Ten strains of a new endophytic ascospore-forming, methanol-assimilating yeast were isolated from the galls induced by sawflies on the leaves of willows in the Losiny Ostrov National Park (Moscow region). Standard phenotypical tests and phylogenetic analyses of 18S rRNA gene, 5.8S-ITS gene region and 26S rRNA gene (D1/D2 domains) sequences showed that the species belongs to the genus Ogataea. We describe it as Ogataea cecidiorum and designate type culture KBP Y-3846 (= CBS 11522^T = VKM Y-2982^T = VKPM Y-3482^T = MUCL 52544^T = NCAIM Y.01965^T) as the type strain. The new species was registered in MycoBank under MB 515233.     

Candida chanthaburiensis sp. nov., Candida kungkrabaensis sp. nov. and Candida suratensis sp. nov., three novel yeast species from decaying plant materials submerged in water of mangrove forests

In a taxonomic study of yeasts isolated from decaying plant materials submerged in water of mangrove forests in Thailand, three strains isolated from tree bark (EM33^T), a fallen leaf (EM40^T) and a detached branch (SM56^T) were found to represent three novel yeast species. On the basis of morphological, biochemical, physiological and chemotaxonomic characteristics, the sequence analysis of the D1/D2 domain of the large subunit (LSU) rRNA gene, and the phylogenetic analysis, the three strains were assigned as three novel Candida species. They were named as Candida chanthaburiensis sp. nov. (type strain EM33^T = BCC 23057^T = NBRC 102176^T = CBS 10926^T), Candida kungkrabaensis sp. nov. (type strain EM40^T = BCC 23060^T = NBRC 102179^T = CBS 10927^T), and Candida suratensis sp. nov. (type strain SM56^T = BCC 25961^T = NBRC 103858^T = CBS 10928^T).     

<Emphasis Type="Italic">Candida neustonensis</Emphasis> sp. nov., a novel ascomycetous yeast isolated from the sea surface microlayer in Taiwan

A new ascomycetous yeast species, Candida neustonensis is proposed in this study based on four strains (SN92^T, SN47, SJ22, SJ25) isolated from sea surface microlayer in Taiwan. These four yeast strains were morphologically, physiologically and phylogenetically identical to each other. No sexual reproduction was observed on 5% malt extract agar, corn meal agar, V8 agar, McClary’s acetate agar and potato-dextrose agar. Phylogenetic analysis of the sequences of the D1/D2 domain of the large subunit (LSU) rRNA gene places C. neustonensis as a member of the Pichia guilliermondii clade, it also reveals that the phylogenetically closest relatives of C. neustonensis are C. fukuyamaensis (4.4% divergence), C. xestobii (4.4% divergence) and P. guilliermondii (4.5% divergence). C. neustonensis also is clearly distinguished from other known species in the P. guilliermondii clade based on the results of physiology tests. From these comparison analyses, the following novel yeast species is proposed: Candida neustonensis sp. nov., with strain SN92^T (= BCRC 23108^T = JCM 14892^T = CBS 11061^T) as the type strain.     

Two new species of the genus Candida in the Zygoascus clade, Candida lundiana sp. nov. and Candida suthepensis sp. nov., isolated from raw honey in Thailand

During a survey of yeasts associated with raw honey collected in Thailand, two strains of the Zygoascus clade were isolated from the Asian cavity-nesting honeybee Apis cerana and the stingless bee Homotrigona fimbriata. Phylogeny based on 26S rDNA D1/D2 sequences placed these yeasts as members of a clade including Candida bituminiphila, Candida patagonica and Candida polysorbophila. The strains of the two novel species, CBS 12271^T and CBS 12270^T, respectively, could be unquestionably distinguished from their relatives by rDNA sequences and other taxonomic characteristics. Therefore, the novel anamorphic species, Candida lundiana sp. nov. (type strain CBS 12271^T = JCM 16823^T) and Candida suthepensis sp. nov. (type strain CBS 12270^T = JCM 16822^T) are described.     

Three new asexual arthroconidial yeasts, Geotrichum carabidarum sp. nov., Geotrichum histeridarum sp. nov., and Geotrichum cucujoidarum sp. nov., isolated from the gut of insects

Twenty arthroconidial yeasts were isolated from the digestive tract of basidiome-feeding beetles and lepidopteran larvae. All of the yeasts reproduced only asexually by arthroconidia and some by endo- or blastoconidia as well. Based on the comparisons of sequences in ribosomal RNA genes and other taxonomic characteristics, the yeasts were identified as three unknown Geotrichum species. The three new species are described as Geotrichum carabidarum (NRRL Y-27727^T), G. histeridarum (NRRL Y-27729^T), and G. cucujoidarum (NRRL Y-27731^T). Phylogenetic analyses from ribosomal DNA sequences showed that members of the genus Geotrichum and related arthroconidial yeast taxa were divided into two major clades: (1) Dipodascus and Galactomyces with Geotrichum anamorphs including all the new species; and (2) Magnusiomyces with Saprochaete anamorphs. G. cucujoidarum formed a subclade with G. fermentans and Geotrichum sp. Y-5419, while the two closely related species, G. carabidarum and G. histeridarum, represent a new basal subclade in the clade of Geotrichum and its teleomorphs.     

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.     

Yeasts of the White Sea intertidal zone and description of Glaciozyma litorale sp. nov.

The intertidal yeast communities inhabiting various environments in the territories of the White Sea Biological Station “Kartesh” (WSBS ZIN RAS) and the N.A. Pertsov White Sea Biological Station (WSBS MSU) were studied. A total of 31 yeast species were isolated using a conventional plating technique and identified using molecular methods. The yeast community of the White Sea intertidal zone consists of members that are typical for marine substrates, ubiquist species that are common in water and in low-temperature terrestrial environments, and a group of species that was isolated from marine substrates for the first time. The most diverse yeast communities formed on the surface of marine algae and in silt. Metschnikowia zobellii, which is a typical inhabitant of northern seas, was the most abundant yeast on algae from both biological stations. A new basidiomycetous yeast species, which was described in this work as Glaciozyma litorale sp. nov., dominated in the silt samples. The type strain of this new species is K94b^T (=KBP 4246^T = VKPM Y-3850^T = PYCC 6252^T = CBS 12957^T = DSM 28204^T); MycoBank registration number is MB 805475.     

<Emphasis Type="Italic">Ogataea phyllophila</Emphasis> sp. nov., <Emphasis Type="Italic">Candida chumphonensis</Emphasis> sp. nov. and <Emphasis Type="Italic">Candida mattranensis</Emphasis> sp. nov., three methylotrophic yeast species from phylloplane in Thailand

Five strains (LN12, LN14^T, LN15^T, LN16 and LN17^T) representing three novel methylotrophic yeast species were isolated from the external surface of plant leaves by three-consecutive enrichments. On the basis of morphological, biochemical, physiological and chemotaxonomic characteristics, the sequence analysis of the D1/D2 domain of the large subunit (LSU) rRNA gene and the phylogenetic analysis, the five strains were assigned to be one novel Ogataea species and two novel Candida species. Three strains (LN12, LN14^T and LN16) represent a single novel species of the genus Ogataea, for which the name Ogataea phyllophila sp. nov. is proposed. The type strain is LN14^T (= BCC 42666^T = NBRC 107780^T = CBS 12095^T). Strain LN15^T was assigned to be Candida chumphonensis sp. nov. (type strain LN15^T = BCC 42667^T = NBRC 107781^T = CBS 12096^T). Strain LN17^T represented another novel species of Candida that was named Candida mattranensis sp. nov. (type strain LN17^T = BCC 42668^T = NBRC 107782^T = CBS 12097^T).     

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 8364^T  =  DBVPG 4489^T), Bandoniozyma aquatica sp. nov. (UFMG-DH4.20^T  =  CBS 12527^T  =  ATCC MYA-4876^T), Bandoniozyma complexa sp. nov. (CBS 11570^T  =  ATCC MYA-4603^T  =  MA28a^T), Bandoniozyma fermentans sp. nov. (CBS 12399^T  =  NU7M71^T  =  BCRC 23267^T), Bandoniozyma glucofermentans sp. nov. (CBS 10381^T  =  NRRL Y-48076^T  =  ATCC MYA-4760^T  =  BG 02-7-15-015A-1-1^T), Bandoniozyma tunnelae sp. nov. (CBS 8024^T  =  DBVPG 7000^T), and Bandoniozyma visegradensis sp. nov. (CBS 12505^T  =  NRRL Y-48783^T  =  NCAIM Y.01952^T).     

Selenium Tolerance of Yeasts

Selenium tolerance of yeasts widely varies: the growth of some yeasts can be inhibited by a selenium concentration as low as 10^–4 M, whereas others can grow in the presence of 10^–1 M selenium. Homogeneous yeast taxa are characterized by a certain level of selenium tolerance, and heterogeneous taxa show a variable level of tolerance to selenium. In general, ascomycetous yeasts are more tolerant to selenium than basidiomycetous yeasts. Among the ascomycetous yeasts, the genera Dekkera and Schizosaccharomyces exhibited the lowest and the species Candida maltosa, Hanseniaspora valbyensis, Kluyveromyces marxianus, and Yarrowia lipolytica the highest tolerance to selenium. Among the basidiomycetous yeasts, the genera Bullera, Cryptococcusand Holtermannia showed the lowest and the species Cryptococcus curvatus, Cr. humicola, and Trichosporon spp. the highest tolerance to selenium. The selenium tolerance of yeasts depends on the composition of the growth medium, in particular, on the presence of sulfate, sulfur-containing amino acids, and glutamine in the medium.     

Characterization of yeast groupings in the phyllosphere of <Emphasis Type="Italic">Sphagnum</Emphasis> mosses

Significant differences were revealed in the taxonomic structure of the epiphytic yeast communities formed on Sphagnum mosses and on the leaves of vascular plants. On mosses, low abundance of red yeasts was found (the most typical epiphytes on vascular plant leaves), along with a relatively high content and diversity of nonpigmented dimorphic basidiomycetes related to the order Leucosporidiales. The species composition of epiphytic yeasts from mosses is different from that of both forest and meadow grasses and of the parts of vascular plants submerged in the turf. The specific composition of the Sphagnum mosses yeast community is probably determined by the biochemical characteristics of this environment, rather than by the hydrothermal regime in the turf.     

<Emphasis Type="Italic">Kazachstania intestinalis</Emphasis> sp. nov., an ascosporogenous yeast from the gut of passalid beetle <Emphasis Type="Italic">Odontotaenius disjunctus</Emphasis>

Three ascosporogenous yeast strains were isolated from the gut of the passalid beetle, Odontotaenius disjunctus, inhabiting on rotten oak trees. DNA sequence comparison and other taxonomic characteristics identified the strains as a novel species in the genus Kazachstania. The name Kazachstania intestinalis sp. nov. (type strain EH085^T = ATCC MYA-4658^T = CBS 11839^T) is proposed for the strains. The yeast is homothallic, producing persistent asci with 1–4 spheroidal ascospores. Molecular phylogeny from ribosomal RNA gene sequences placed this novel species on the basal lineage of a clade including Kazachstania lodderae, Kazachstania exigua, Kazachstania martiniae, and other related Kazachstania spp., but none of those species was a close sister to K. intestinalis.     

Trichosporon vanderwaltii sp. nov., an asexual basidiomycetous yeast isolated from soil and beetles

During a survey of unidentified yeast isolates deposited in the UNESCO-MIRCEN Biotechnological Yeast Culture Collection housed at the Department of Microbial, Biochemical and Food Biotechnology of the University of the Free State, one isolate obtained from soil in South Africa showed 100 % identity in D1/D2 rDNA sequence with undescribed basidiomycetous yeasts isolated from the gut of beetles from the United States of America and forest soil from Taiwan in the NCBI sequence database. Phylogenetic analyses using sequences of the D1/D2 rDNA and ITS regions indicated that all these isolates form a well-supported sub-clade that is the sister clade to the Brassicae plus Porosum clades of Trichosporon in the order Trichosporonales. Subsequent phenotypic tests revealed that asexual reproduction by budding is rare but dominated by arthroconidia resulting from segmentation of hyphae and that fusiform giant cells are characterized by budding from a broad base. These findings further suggest that these isolates belong to a single tremellomycetous yeast species for which the name Trichosporon vanderwaltii CBS 12124^T (=NRRL Y-48732^T, =UOFS Y-1920^T) is proposed.     

The use of parsimony network analysis for the formal delineation of phylogenetic species of yeasts: Candida apicola, Candida azyma, and Candida parazyma sp. nov., cosmopolitan yeasts associated with floricolous insects

Parsimony network analysis of rDNA sequences was used to delimit phylogenetic species of yeasts in an objective, formal manner. Many strains assigned to Candida apicola (Starmerella clade), when compared to the type, fell outside the inclusion limits proposed by Kurtzman and Robnett (1998) based on a pair-wise comparison of the large subunit rRNA gene D1/D2 domains. However, when these sequences were analyzed jointly with ITS rDNA sequences by parsimony network analysis, 28 of the 30 strains formed a cohesive set. Two strains, MUCL 45721 and CBS 4353, were excluded from the species, but there was no evident justification to subdivide the rest. A similar analysis of 81 isolates originally assigned to Candida azyma (Wickerhamiella clade) yielded dramatically different results, giving rise to six independent networks corresponding to Candida azyma sensu stricto (18 strains), Candida azymoides (2 strains), a pair of isolates from Australian hibiscus flowers, a single isolate from the same substrate, a single isolate from Malaysian bertam palm nectar, and 57 isolates that are assigned to the new species Candida parazyma (type = UWOPS 91-652.1^T = CBS 11563^T = NRRL Y-48669^T). The strains retained in C. azyma sensu stricto differed from one another by up to four substitutions in their D1/D2 sequences, but their polymorphism at the level of the ITS was considerable and suggested a history of divergence resulting from dispersal. Strains of C. parazyma fell into seven variant haplotypes based on sequences of the rDNA ITS and D1/D2 regions. The most abundant haplotype occurred across the global range of the species. Others were either endemic to Belize, Costa Rica, Rarotonga, or Tennessee, suggestive of vicariance, or occurred across remote localities, offering partial support to the notion of rapid dispersal.     

Torulaspora indica a novel yeast species isolated from coal mine soils

Four yeast strains (APSS 805, APSS 806, APSS 815 and AP-18) belonging to a novel Torulaspora species were isolated from coal mine soils of Singareni in Andhra Pradesh state, India. Another strain (PBA-22) was isolated from agricultural field soil from Gujarat state, India. The vegetative cells of all these strains were round, haploid and produced asci by conjugation between independent cells or mother cell and bud, with rough ascospores, suggesting their possible relation to ascomycetous yeast genus Torulaspora. Phylogenetic analysis of the D1/D2 domain of the large subunit (LSU) rRNA gene and Internal Transcribed Spacer (ITS) regions revealed that, among the five strains, three viz. APSS 805, APSS 806 and APSS 815 have identical sequences. The other two strains (AP-18 and PBA-22) differed from the other three strains in less than 1% nucleotide substitutions in the combined D1/D2 domain and ITS sequences, indicating that all of them (five strains) may belong to the same species. These five strains were closely related to Torulaspora globosa, but showed more than 3–7% sequence divergence from T. globosa and all other species in the genus Torulaspora in the combined sequence analysis of D1/D2 domain and ITS region of rRNA gene. In addition, these strains also showed distinct microsatellite finger-printing pattern from related species and differed in several physiological responses suggesting that these strains belong to a novel species of Torulaspora. We propose to name these strains as Torulaspora indica sp. nov., and designate APSS 805^T = MTCC 9772 ^T = CBS 12408 ^T as the type strain of this novel species. The Mycobank number of the novel species is MB 563738.     

Community Structure of Yeast Fungi in Forest Biogeocenoses

The results of longterm studies of yeasts inhabiting soil, plant surfaces, and plant residues in typical subboreal forests of the European part of Russia are summarized. The cell number and species diversity of yeast communities in the array of substrates corresponding to succession stages in plant residue decomposition are shown to steadily decline. Each stage is characterized by its specific set of dominating species. The yeast diversity in forest biogeocenoses is shown to surpass that in other geographic zones. This manifests itself in a greater number of species occurring in similar arrays of substrates, in the absence of conspicuous dominants on the biogeocenotic level, and in a higher differentiation of the yeast population with respect to its habitat type. The forest yeast populations are also characterized by a high diversity of yeasts of ascomycetous affinity and of the anamorphic stages of Taphrinales and Tremellales and by the presence of typical pedobiont species (except Lipomyces spp.).     

Metschnikowia noctiluminum sp. nov., Metschnikowia corniflorae sp. nov., and Candida chrysomelidarum sp. nov., isolated from green lacewings and beetles

Fourteen yeast isolates belonging to the Metschnikowia clade were isolated from the digestive tracts of lacewings (Neuroptera: Chrysopidae), soldier beetles and leaf beetles (Coleoptera: Cantharidae and Chrysomelidae), and a caddisfly (Trichoptera: Hydropsychidae). The insect hosts were associated with sugary substances of plants, a typical habitat for yeasts in this clade. Based on DNA sequence comparisons and phenetic characters, the yeasts were identified as Candida picachoensis, Candida pimensis, and four undescribed taxa. Among the undescribed taxa, three yeasts were distinguished from one another and from other described taxa by nucleotide differences in the ribosomal DNA repeat, which were sufficient to consider them as new species. Two of the novel yeast species are described as Metschnikowia noctiluminum (NRRL Y-27753^T) and M. corniflorae spp. nov. (NRRL Y-27750^T) based in part on production of needle-shaped ascospores, which are found in most Metschnikowia species. Sexual reproduction was not observed in the third new yeast, Candida chrysomelidarum sp. nov. (NRRL Y-27749^T). A fourth isolate, NRRL Y-27752, was not significantly distinct from Metschnikowia viticola and Candida kofuensis to be described as a new species. Phylogenetic analysis of the D1/D2 loop sequences placed M. noctiluminum within the M. viticola clade, while C. chrysomelidarum was a sister taxon of Candida rancensis. Metschnikowia corniflorae was phylogenetically distinct from other new species and fell outside of the large-spored Metschnikowia group.     

<Emphasis Type="Italic">Rhodotorula taiwanensis</Emphasis> sp. nov., a novel yeast species from a plant in Taiwan

A novel anamorphic yeast strain, A1-01^T, belonging to the genus Rhodotorula was isolated from a plant in Taiwan and analysed morphologically, physiologically and phylogenetically. Neither ballistoconidia nor sexual reproduction was observed. Sequence analysis of the 26S rRNA gene and the ITS region indicate that Rhodosporidium sphaerocarpum is the most closely related species, with 14 and 24 nucleotide substitutions, respectively. The novel species differed physiologically from R. sphaerocarpum in its ability to assimilate ethylamine and cadaverine, its inability to assimilate ethanol and nitrite. From these comparative analyses, the following novel yeast species is proposed: Rhodotorula taiwanensis sp. nov. with the type strain of A1-01^T (BCRC 23118^T = CBS 11729^T).     

Yeasts in an industrial malting ecosystem

The malting ecosystem consists of two components: the germinating cereal grains and the complex microbial community. Yeasts and yeast-like fungi are an important part of this ecosystem, but the composition and the effects of this microbial group have been largely unknown. In this study we surveyed the development of yeasts and yeast-like fungi in four industrial scale malting processes. A total of 136 malting process samples were collected and examined for the presence of yeasts growing at 15, 25 and 37°C. More than 700 colonies were isolated and characterized. The isolates were discriminated by PCR-fingerprinting with microsatellite primer (M13). Yeasts representing different fingerprint types were identified by sequence analysis of the D1/D2 domain of the 26S rRNA gene. Furthermore, identified yeasts were screened for the production of α-amylase, β-glucanase, cellulase and xylanase. A numerous and diverse yeast community consisting of both ascomycetous (25) and basidiomycetous (18) species was detected in the various stages of the malting process. The most frequently isolated ascomycetous yeasts belonged to the genera Candida, Clavispora, Galactomyces, Hanseniaspora, Issatchenkia, Pichia, Saccharomyces and Williopsis and the basidiomycetous yeasts to Bulleromyces, Filobasidium, Cryptococcus, Rhodotorula, Sporobolomyces and Trichosporon. In addition, two ascomycetous yeast-like fungi (black yeasts) belonging to the genera Aureobasidium and Exophiala were commonly detected. Yeasts and yeast-like fungi produced extracellular hydrolytic enzymes with a potentially positive contribution to the malt enzyme spectrum. Knowledge of the microbial diversity provides a basis for microflora management and understanding of the role of microbes in the cereal germination process.