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Sample records for anamorphic yeast species

  1. Candida bituminiphila, a novel anamorphic species of yeast.

    PubMed

    Robert, V; Bonjean, B; Karutz, M; Paschold, H; Peeters, W; Wubbolts, M G

    2001-11-01

    A novel anamorphic species of yeast belonging to the genus Candida was isolated from tar in Canada. Morphological and physiological observations, as well as phylogenetic analyses, were performed. Conidiophores were produced, were usually short and had sympodial growth, numerous bud scars and a rachis-like structure. They bore one or more conidia. Pseudomycelium was scarcely produced and true mycelium was sparse. No sexual reproduction was observed on corn meal, malt, Gorodkowa, Dextrose Yeast Peptone or V8 agars. Zygoascus hellenicus was physiologically the most closely related species, but it differed from the novel species by its ability to assimilate D-galacturonate and L-rhamnose, ferment sucrose and grow at 37 degrees C. From sequence analysis of the 26S rDNA D1/D2 region, Z. hellenicus and Candida bertae var. bertae were the closest species with 54 and 56 bp substitutions, respectively. Similar results have been obtained from analysis of the 18S rDNA. All these data support the hypothesis that the yeast, named Candida bituminiphila, is a novel species closely related to Z. hellenicus. The holotype and only isolate of C. bituminiphila is strain CBS 8813T (= MUCL 41424T). PMID:11760960

  2. Pseudozyma vetiver sp. nov., a novel anamorphic ustilaginomycetous yeast species isolated from the phylloplane in Thailand.

    PubMed

    Chamnanpa, Thunnicha; Limtong, Pitayakon; Srisuk, Nantana; Limtong, Savitree

    2013-11-01

    Three strains representing one novel yeast species were isolated from the phylloplanes of the vetiver grasses (DMKU-LV90 and DMKU-LV99(T)) and sugarcane (DMKU-SP260) collected in Thailand by leaf washing followed by a plating technique. On the basis of morphological, biochemical, physiological and chemotaxonomic characteristics and the sequence analysis of the D1/D2 region of the large subunit (LSU) rRNA gene and the internal transcribed spacer region (ITS), the three strains were found to represent a single novel anamorphic ustilaginomycetous yeast species in the genus Pseudozyma. The name Pseudozyma vetiver sp. nov. is proposed for this novel species. The type strain is DMKU-LV99(T) (BCC 61021 = CBS 12824). The novel species showed phylogenetic relationships to the other members of the genus Pseudozyma and to teleomorphic fungal genera, namely Ustilago, Sporisorium and Anomalomyces in Ustilaginaceae, Ustilaginales. The three strains showed identical sequences both in the D1/D2 and ITS regions. The Pseudozyma species closest to the novel species in terms of pairwise sequence similarity in the D1/D2 region was Pseudozyma pruni but with 2.3 % nucleotide substitutions (14 nucleotide substitutions and no gaps out of 606 nt). The novel species and P. pruni differed by 10.9 % nucleotide substitutions (75 nucleotide substitutions and 31 gaps out of 691 nt) in the ITS region. The phylogenetic analysis based on the combined sequences of the ITS region and the D1/D2 region of the LSU rRNA gene showed that the novel species was found to be most closely related to Pseudozyma fusiformata but with 2.9 % nucleotide substitutions in the D1/D2 region and 7.4 % nucleotide substitutions in the ITS region. PMID:23877892

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

    PubMed

    Limtong, Savitree; Kaewwichian, Rungluk; Jindamorakot, Sasitorn; Yongmanitchai, Wichien; Nakase, Takashi

    2012-06-01

    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)). PMID:22331449

  4. Starmerella caucasica sp. nov., a novel anamorphic yeast species isolated from flowers in the Caucasus.

    PubMed

    Sipiczki, Matthias

    2013-01-01

    Taxonomic analysis of budding yeast strains isolated from flowers of Wisteria sinensis (Fabales, Fabaceae) abundantly visited by flying insects, mainly bees in city parks of Baku is described. The isolates forming slightly pink colonies and propagating by budding represent a hitherto unknown yeast species for which the name Starmerella caucasica is proposed. The sequences of the D1/D2 domains of the large subunit rRNA genes and the ITS1-5.8S-ITS2 regions were highly similar in the isolates and indicated a close relationship with Candida kuoi and Starmerella bombicola in the phylogenetic analysis. S. caucasica can be separated from these species by its growth on glucosamine and D-tryptophan, in vitamin-free medium and at 37°C, and its inability to grow on citrate, ethylamine, cadaverine and in media supplemented with 0.01% of cycloheximide. The type strain is 11-1071.1(T). It has been deposited in Centralbureau voor Schimmelcultures (Utrecht, the Netherlands) as CBS 12650(T), the National Collection of Agricultural and Industrial Microorganisms (Budapest, Hungary) as NCAIM Y.02030(T) and the Culture Collection of Yeasts (Bratislava, Slovakia) as CCY 90-1-1(T). The GenBank accession numbers for nucleotide sequences of S. caucasica are JX112043 (D1/D2 domain of the 26S rRNA gene) and JX112044 (ITS1-5.8S-ITS2). Mycobank: MB 800536. PMID:23518520

  5. Candida kuoi sp. nov., a new anamorphic species of the Starmerella yeast clade that synthesizes sophorolipids

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Candida kuoii sp. nov. (NRRL Y-27208T, CBS 7267T, type strain) is described from a strain isolated from concentrated grape juice in Cape Province, South Africa. Analysis of sequences from the D1/D2 domains of the nuclear large subunit rRNA gene separated the proposed new species from Starmerella bom...

  6. Candida digboiensis sp. nov., a novel anamorphic yeast species from an acidic tar sludge-contaminated oilfield.

    PubMed

    Prasad, G S; Mayilraj, S; Sood, Nitu; Singh, Vijeyta; Biswas, Kakoli; Lal, Banwari

    2005-03-01

    Two strains (TERI-6(T) and TERI-7) of a novel yeast species were isolated from acidic tar sludge-contaminated soil samples collected from Digboi Refinery, Assam, India. These two yeast strains were morphologically, physiologically and phylogenetically identical to each other. No sexual reproduction was observed on corn meal, malt, Gorodkowa, YM or V8 agars. Physiologically, the novel isolates were most closely related to Candida blankii, but differed in eight physiological tests. The prominent differences were the ability of the isolates to assimilate melibiose and inulin and their inability to assimilate d-glucuronate, succinate and citrate. Phylogenetic analysis using the D1/D2 variable domain showed that the closest relative of these strains is C. blankii (2.8 % divergence). Other related species are Zygoascus hellenicus and Candida bituminiphila. The isolates differed from C. blankii by 11 base substitutions in the 18S rRNA gene sequence and by 58 base substitutions in the internal transcribed spacer sequences. The physiological, biochemical and molecular data support the contention that strains TERI-6(T) and TERI-7 represent a novel species, for which the name Candida digboiensis sp. nov. is proposed. The type strain is TERI-6(T) (=MTCC 4371(T)=CBS 9800(T)=JCM 12300(T)). PMID:15774693

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

    PubMed

    Nakase, Takashi; Jindamorakot, Sasitorn; Am-In, Somit; Lee, Ching-Fu; Imanishi, Yumi; Limtong, Savitree

    2011-01-01

    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. PMID:21606608

  8. On the reclassification of species assigned to Candida and other anamorphic ascomycetous yeast genera based on phylogenetic circumscription

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Multigene phylogenies have been instrumental in revising the classification of ascosporic (teleomorph) yeasts in a natural system based on lines of decent. Although many taxonomic changes have already been implemented for teleomorph taxa, this is not yet the case for the large genus Candida and smal...

  9. Blastobotrys americana sp. nov., B. illinoisensis sp. nov., B. malaysiensis sp. nov., B. muscicola sp. nov., B. peoriensis sp. nov. and B. raffinofermentans sp. nov., six anamorphic yeast species

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The genus Blastobotrys, which now includes species previously assigned to the synonymous genera Arxula and Sympodiomyces, represents the anamorph of the ascosporogenous genus Trichomonascus. Six new species are proposed for assignment to Blastobotrys and were detected from their unique nucleotide s...

  10. Calonectria species and their Cylindrocladium anamorphs: species with clavate vesicles

    PubMed Central

    Crous, Pedro W.; Groenewald, Johannes Z.; Risède, Jean-Michel; Simoneau, Philippe; Hyde, Kevin D.

    2006-01-01

    The present study compares all known species of Cylindrocladium that have clavate vesicles. Several isolates were obtained from baited soils collected in various parts of the world, while others were associated with leaf litter or symptomatic plant hosts. Isolates were compared based on morphology, as well as DNA sequence data from their β-tubulin and histone gene H3 regions. Cylindrocladium australiense and Cy. ecuadoriae, are described as new species, a decision based on morphology and molecular data. A group of isolates associated with toppling disease of banana in the West Indies is identified as Cy. flexuosum. An epitype is designated for Cy. ilicicola, and a new name, Curvicladiella, proposed to replace the anamorphic genus Curvicladium, which is a homonym. PMID:18490981

  11. New anamorphic yeast species: Candida infanticola sp. nov., Candida polysorbophila sp. nov., Candida transvaalensis sp. nov., and Trigonopsis californica sp. nov.

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Three new species of Candida and a new species of Trigonopsis are described based on their recognition from phylogenetic analysis of gene sequences from large subunit ribosomal RNA, ITS1/ITS2 rRNA, mitochondrial small subunit rRNA and cytochrome oxidase II. Candida infanticola sp. nov. (type strain...

  12. Taxonomy and phylogenetic relationships of nine species of Hypocrea with anamorphs assignable to Trichoderma section Hypocreanum

    PubMed Central

    Overton, Barrie E.; Stewart, Elwin L.; Geiser, David M.

    2006-01-01

    Morphological studies and phylogenetic analyses of DNA sequences from the internal transcribed spacer (ITS) regions of the nuclear ribosomal gene repeat, a partial sequence of RNA polymerase II subunit (rpb2), and a partial sequence of the large exon of tef1 (LEtef1) were used to investigate the taxonomy and systematics of nine Hypocrea species with anamorphs assignable to Trichoderma sect. Hypocreanum. Hypocrea corticioides and H. sulphurea are reevaluated. Their Trichoderma anamorphs are described and the phylogenetic positions of these species are determined. Hypocrea sulphurea and H. subcitrina are distinct species based on studies of the type specimens. Hypocrea egmontensis is a facultative synonym of the older name H. subcitrina. Hypocrea with anamorphs assignable to Trichoderma sect. Hypocreanum formed a well-supported clade. Five species with anamorphs morphologically similar to sect. Hypocreanum, H. avellanea, H. parmastoi, H. megalocitrina, H. alcalifuscescens, and H. pezizoides, are not located in this clade. Protocrea farinosa belongs to Hypocrea s.s. PMID:18490989

  13. Taxonomy and phylogenetic relationships of nine species of Hypocrea with anamorphs assignable to Trichoderma section Hypocreanum.

    PubMed

    Overton, Barrie E; Stewart, Elwin L; Geiser, David M

    2006-01-01

    Morphological studies and phylogenetic analyses of DNA sequences from the internal transcribed spacer (ITS) regions of the nuclear ribosomal gene repeat, a partial sequence of RNA polymerase II subunit (rpb2), and a partial sequence of the large exon of tef1 (LEtef1) were used to investigate the taxonomy and systematics of nine Hypocrea species with anamorphs assignable to Trichoderma sect. Hypocreanum. Hypocrea corticioides and H. sulphurea are reevaluated. Their Trichoderma anamorphs are described and the phylogenetic positions of these species are determined. Hypocrea sulphurea and H. subcitrina are distinct species based on studies of the type specimens. Hypocrea egmontensis is a facultative synonym of the older name H. subcitrina. Hypocrea with anamorphs assignable to Trichoderma sect. Hypocreanum formed a well-supported clade. Five species with anamorphs morphologically similar to sect. Hypocreanum, H. avellanea, H. parmastoi, H. megalocitrina, H. alcalifuscescens, and H. pezizoides, are not located in this clade. Protocrea farinosa belongs to Hypocrea s.s. PMID:18490989

  14. Discussion of teleomorphic and anamorphic Ascomycetous yeasts and yeast-like taxa

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The relationship of ascomycetous yeasts with other members of the ascomycete fungi (Ascomycota) has been controversial for over 100 years. Because yeasts are morphologically simple, it was proposed that they represent primitive forms of ascomycetes (e.g., Guilliermond 1912). Alternatively, the ide...

  15. Taxonomy and phylogeny of the ascomycetous yeast genus Zygoascus, with proposal of Zygoascus meyerae sp. nov. and related anamorphic varieties.

    PubMed

    Smith, Maudy Th; Robert, V; Poot, G A; Epping, Wendy; de Cock, A W A M

    2005-05-01

    Physiological characters, mating compatibility, PCR-RAPD fingerprints, mol% G + C content, DNA-DNA relatedness, and large-subunit and internal transcribed spacer rRNA gene sequences of strains assigned to the genus Zygoascus were re-examined. On the basis of those data, and after phylogenetic analyses, an emendation of Zygoascus hellenicus (type material is a cross of CBS 6736(T) x CBS 5839(T)) is proposed, comprising two novel anamorphic varieties, Candida steatolytica var. steatolytica (CBS 6736(T)) and C. steatolytica var. inositophila (CBS 5839(T)). A novel teleomorphic species, Zygoascus meyerae sp. nov. (type material is a cross of CBS 4099(T) x CBS 7521(T)) is described, together with two novel anamorphic varieties corresponding to it, Candida hellenica var. hellenica (CBS 4099(T)) and C. hellenica var. acidophila (CBS 7115(T)). PMID:15879282

  16. Molecular studies on terricolous microfungi reveal novel anamorphs of two Tuber species.

    PubMed

    Urban, Alexander; Neuner-Plattner, Isabell; Krisai-Greilhuber, Irmgard; Haselwandter, Kurt

    2004-07-01

    This study reports novel terricolous mitosporic fungal morphs nested in the genus Tuber according to molecular phylogenetic analysis. Fungal DNA was amplified directly from field-collected anamorph samples. Nuclear ribosomal DNA (nrDNA) sequences including the ITS regions and the D1 and D2 domains of the LSU identify the anamorphs as mitosporic Tuber borchii and Tuber oligospermum. The link of the novel anamorphs to the genus Tuber is confirmed by the comparative analysis of five collections from four sampling sites. Ectomycorrhizas with characteristic features of Tuber borchii ectomycorrhizas were found in the soil volume collected with one of the mitosporic T. borchii collections. A nrDNA sequence amplified from these ectomycorrhizae is identical with the corresponding anamorph sequence. The possible role of the newly discovered anamorphs in the Tuber life-cycle and the potential significance of anamorphs for the propagation of ectomycorrhizal fungi are discussed. PMID:15446707

  17. Analysis of expressed sequence tags from the anamorphic basidiomycetous yeast, Pseudozyma antarctica, which produces glycolipid biosurfactants, mannosylerythritol lipids.

    PubMed

    Morita, Tomotake; Konishi, Masaaki; Fukuoka, Tokuma; Imura, Tomohiro; Kitamoto, Dai

    2006-07-15

    Pseudozyma antarctica T-34 secretes a large amount of biosurfactants (BS), mannosylerythritol lipids (MEL), from different carbon sources such as hydrocarbons and vegetable oils. The detailed biosynthetic pathway of MEL remained unknown due to lack of genetic information on the anamorphic basidiomycetous yeasts, including the genus Pseudozyma. Here, in order to obtain genetic information on P. antarctica T-34, we constructed a cDNA library from yeast cells producing MEL from soybean oil and identified the genes expressed through the creation of an expressed sequence tags (EST) library. We generated 398 ESTs, assembled into 146 contiguous sequences. Based upon a BLAST search similarity cut-off of E

  18. Anamorphic Art

    ERIC Educational Resources Information Center

    Foster, Colin

    2006-01-01

    During the 17th century, Baroque decoration used anamorphism to combine actual architectural elements with illusionistic painting. When viewed from a particular point in space, the architecture blends with painting to form a combined image. In this article, Julian Beever, a leading anamorphic pavement artist, explains to the author the principles…

  19. A revision of Cyanonectria and Geejayessia gen. nov., and related species with Fusarium-like anamorphs

    PubMed Central

    Schroers, H.-J.; Gräfenhan, T.; Nirenberg, H.I.; Seifert, K.A.

    2011-01-01

    A revision of Fusarium-like species associated with the plant genus Buxus led to a reconsideration of generic concepts in the Fusarium clade of the Nectriaceae. Phylogenetic analyses of the partial second largest subunit of the RNA polymerase II (rpb2) and the larger subunit of the ATP citrate lyase (acl1) gene exons confirm the existence of a clade, here called the terminal Fusarium clade, that includes genera such as Fusarium sensu stricto (including its Gibberella teleomorphs), Albonectria, Cyanonectria, “Haematonectria”, the newly described genus Geejayessia, and “Nectria” albida. Geejayessia accommodates five species. Four were previously classified in Nectria sensu lato, namely the black perithecial, KOH–species G. atrofusca and the orange or reddish, KOH+ G. cicatricum, G. desmazieri and G. zealandica. Geejayessia celtidicola is newly described. Following our phylogenetic analyses showing its close relationship with Cyanonectria cyanostoma, the former Gibbera buxi is recombined as the second species of Cyanonectria. A three gene phylogenetic analysis of multiple strains of each morphological species using translation elongation factor 1 α (tef-1), rpb2 and acl1 gene exons and introns confirms their status as distinct phylogenetic species. Internal transcribed spacer of the ribosomal RNA gene cluster and nuclear large ribosomal subunit sequences were generated as additional DNA barcodes for selected strains. The connection of Fusarium buxicola, often erroneously reported as the anamorph of G. desmazieri, with the bluish black and KOH+ perithecial species C. buxi is reinstated. Most Cyanonectria and Geejayessia species exhibit restricted host ranges on branches or twigs of Buxus species, Celtis occidentalis, or Staphylea trifolia. Their perithecia form caespitose clusters on well-developed, mostly erumpent stromata on the bark or outer cortex of the host and are relatively thin-walled, mostly smooth, and therefore reminiscent of the more or less

  20. A revision of Cyanonectria and Geejayessia gen. nov., and related species with Fusarium-like anamorphs.

    PubMed

    Schroers, H-J; Gräfenhan, T; Nirenberg, H I; Seifert, K A

    2011-01-01

    A revision of Fusarium-like species associated with the plant genus Buxus led to a reconsideration of generic concepts in the Fusarium clade of the Nectriaceae. Phylogenetic analyses of the partial second largest subunit of the RNA polymerase II (rpb2) and the larger subunit of the ATP citrate lyase (acl1) gene exons confirm the existence of a clade, here called the terminal Fusarium clade, that includes genera such as Fusariumsensu stricto (including its Gibberella teleomorphs), Albonectria, Cyanonectria, "Haematonectria", the newly described genus Geejayessia, and "Nectria" albida. Geejayessia accommodates five species. Four were previously classified in Nectria sensu lato, namely the black perithecial, KOH-species G. atrofusca and the orange or reddish, KOH+ G. cicatricum, G. desmazieri and G. zealandica.Geejayessia celtidicola is newly described. Following our phylogenetic analyses showing its close relationship with Cyanonectria cyanostoma, the former Gibbera buxi is recombined as the second species of Cyanonectria. A three gene phylogenetic analysis of multiple strains of each morphological species using translation elongation factor 1 α (tef-1), rpb2 and acl1 gene exons and introns confirms their status as distinct phylogenetic species. Internal transcribed spacer of the ribosomal RNA gene cluster and nuclear large ribosomal subunit sequences were generated as additional DNA barcodes for selected strains. The connection of Fusarium buxicola, often erroneously reported as the anamorph of G. desmazieri, with the bluish black and KOH+ perithecial species C. buxi is reinstated. Most Cyanonectria and Geejayessia species exhibit restricted host ranges on branches or twigs of Buxus species, Celtisoccidentalis, or Staphyleatrifolia. Their perithecia form caespitose clusters on well-developed, mostly erumpent stromata on the bark or outer cortex of the host and are relatively thin-walled, mostly smooth, and therefore reminiscent of the more or less astromatous

  1. Eighteen new oleaginous yeast species.

    PubMed

    Garay, Luis A; Sitepu, Irnayuli R; Cajka, Tomas; Chandra, Idelia; Shi, Sandy; Lin, Ting; German, J Bruce; Fiehn, Oliver; Boundy-Mills, Kyria L

    2016-07-01

    Of 1600 known species of yeasts, about 70 are known to be oleaginous, defined as being able to accumulate over 20 % intracellular lipids. These yeasts have value for fundamental and applied research. A survey of yeasts from the Phaff Yeast Culture Collection, University of California Davis was performed to identify additional oleaginous species within the Basidiomycota phylum. Fifty-nine strains belonging to 34 species were grown in lipid inducing media, and total cell mass, lipid yield and triacylglycerol profiles were determined. Thirty-two species accumulated at least 20 % lipid and 25 species accumulated over 40 % lipid by dry weight. Eighteen of these species were not previously reported to be oleaginous. Triacylglycerol profiles were suitable for biodiesel production. These results greatly expand the number of known oleaginous yeast species, and reveal the wealth of natural diversity of triacylglycerol profiles within wild-type oleaginous Basidiomycetes. PMID:27072563

  2. Candida lignophila sp. nov., a new basidiomycetous yeast anamorph from rotting wood of Drimys winteri.

    PubMed

    Dill, I; Ramírez, C; González, A

    1984-01-01

    Two strains of an undescribed Candida species were isolated from samples of a rotting trunk of Drimys winteri collected on the isle of Chiloé in South Chile. A description of the new species Candida lignophila is given and its relationship to other species is discussed with particular emphasis on its typical basidiomycetous properties as well as on its ecological habitat. PMID:6541456

  3. Cryptococcus anemochoreius sp. nov., a novel anamorphic basidiomycetous yeast isolated from the atmosphere in central South Africa.

    PubMed

    Pohl, Carolina H; Kock, Johan L F; van Wyk, Pieter W J; Albertyn, Jacobus

    2006-11-01

    A novel yeast strain, CBS 10258T, was isolated from the atmosphere in central South Africa. Sequence analysis of the D1/D2 domain and internal transcribed spacer region of the novel strain indicates that it represents a novel species within the Cryptococcus laurentii complex. Phylogenetic analyses based on the D1/D2 domain revealed that the novel strain occupies a relatively isolated position within this complex with Papiliotrema bandonii, Cryptococcus perniciosus, Cryptococcus nemorosus and Cryptococcus sp. CBS 8363 being the closest relatives. However, the novel strain could be distinguished from related species by standard physiological tests including the inability to assimilate rhamnose, methyl alpha-d-glucoside, salicin, lactose, erythritol, ribitol, xylitol, citrate and ethanol. In addition, no extracellular starch production was observed and the isolate was able to grow in the absence of additional vitamins. On the basis of these results, we suggest that the new strain represents a novel species for which the name Cryptococcus anemochoreius sp. nov. is proposed [type strain CBS 10258T (=NRRL Y-27920T)]. PMID:17082415

  4. Candida patagonica sp. nov., a new species of yeast from cellar surfaces.

    PubMed

    Sangorrín, Marcela P; Lopes, Christian A; Belloch, Carmela; Querol, Amparo; Caballero, Adriana C

    2007-07-01

    A novel anamorphic yeast species belonging to the genus Candida has been isolated from cellar surfaces in North Patagonia. Morphological and physiological observation and phylogenetic analysis were performed. Pseudomycelium was plentifully produced. No sexual reproduction was observed. From sequence analysis of the 26S rDNA D1/D2 region, Candida bituminiphila and Zygoascus hellenicus were the closest species with 40 and 79 bp substitutions, respectively. C. bituminiphila differed physiologically from the novel species in its ability to assimilate sucrose and erythritol, in not fermenting any sugars, in growing without some vitamin compounds, and in growing at 40 degrees C. All these data support the hypothesis that the new yeast, named Candida patagonica, is a novel species related to C. bituminiphila. The type strain is UNCOMA 159.5 (= CECT 12029 = CBS 10443). PMID:17265102

  5. Cryptococcus randhawai sp. nov., a novel anamorphic basidiomycetous yeast isolated from tree trunk hollow of Ficus religiosa (peepal tree) from New Delhi, India.

    PubMed

    Khan, Zia U; Ahmad, Suhail; Hagen, Ferry; Fell, Jack W; Kowshik, Tusharantak; Chandy, Rachel; Boekhout, Teun

    2010-03-01

    A novel anamorphic Cryptococcus species is described, which was isolated in New Delhi (India) from decaying wood of a tree trunk hollow of Ficus religiosa. On the basis of sequence analysis of the D1/D2 domains of the 26S rRNA gene and the internally transcribed spacer (ITS)-1 and ITS-2 region sequences, the isolate belonged to the Cryptococcus albidus cluster (Filobasidiales, Tremellomycetes) and was closely related to Cryptococcus saitoi, Cryptococcus cerealis and Cryptococcus friedmannii with 98% sequence identity. Phenotypically, the species differed from C. saitoi with respect to growth temperature (up to 37degrees C), presence of a thin capsule, ability to grow in the absence of vitamins, and inability to assimilate citrate and ethylamine. With respect to C. friedmannii, it differed in growth temperature, ability to assimilate lactose, raffinose, L: -rhamnose, myo-inositol, and inability to utilize citrate. Furthermore, our isolate also differed from C. cerealis in growth temperature, presence of capsule and inability to assimilate L: -sorbose. In view of the above phenotypic differences and unique rDNA sequences, we consider that our isolate represents a new species of Cryptococcus, and therefore, a new species, Cryptococcus randhawai is proposed for this taxon. The type strain J11/2002 has been deposited in the culture collection of the Centraalbureau voor Schimmelcultures (CBS10160) and CABI Biosciences (IMI 393306). PMID:20091225

  6. Description of Kuraishia piskuri f.a., sp. nov., a new methanol assimilating yeast and transfer of phylogenetically related Candida species to the genera Kuraishia and Nakazawaea as new combinations

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The new anamorphic yeast Kuraishia piskuri, f.a., sp. nov. is described for three strains that were isolated from insect frass from trees growing in Florida, USA (type strain, NRRL YB-2544, CBS 13714). Species placement was based on phylogenetic analysis of nuclear gene sequences for the D1/D2 domai...

  7. The anamorphic universe

    NASA Astrophysics Data System (ADS)

    Ijjas, Anna; Steinhardt, Paul J.

    2015-10-01

    We introduce ``anamorphic'' cosmology, an approach for explaining the smoothness and flatness of the universe on large scales and the generation of a nearly scale-invariant spectrum of adiabatic density perturbations. The defining feature is a smoothing phase that acts like a contracting universe based on some Weyl frame-invariant criteria and an expanding universe based on other frame-invariant criteria. An advantage of the contracting aspects is that it is possible to avoid the multiverse and measure problems that arise in inflationary models. Unlike ekpyrotic models, anamorphic models can be constructed using only a single field and can generate a nearly scale-invariant spectrum of tensor perturbations. Anamorphic models also differ from pre-big bang and matter bounce models that do not explain the smoothness. We present some examples of cosmological models that incorporate an anamorphic smoothing phase.

  8. Cordyceps bassiana and production of stromata in vitro showing Beauveria anamorph in Korea

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A Cordyceps species was found with Beauveria anamorph state on larval insect cadavers on Obong Mountsin in Gangwon Pronvince, Republic of Korea. Cultures from discharged ascospores formed an anamorph identifiable as Beauveria bassiana. This teleomorph-anamorph connection was also confirmed by the in...

  9. The Secret of Anamorphic Art.

    ERIC Educational Resources Information Center

    Johnson, Art; Martin, Joan D.

    1998-01-01

    Defines and discusses anamorphic art and describes an anamorphic art activity using the reflection of mirrored cylinders through a grid system. Particularly suitable for algebra or geometry classes. Requires some minimal skills from coordinate geometry and spatial visualization. (AIM)

  10. Phylogeny and systematics of the anamorphic, entomopathogenic genus Beauveria

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Beauveria is a cosmopolitan anamorph genus of arthropod pathogens that includes the agronomically important species B. bassiana and B. brongniartii, which are used as mycoinsecticides for the biological control of pest insects. Recent phylogenetic evidence demonstrates that Beauveria is monophyletic...

  11. Description of Kuraishia piskuri f.a., sp. nov., a new methanol assimilating yeast and transfer of phylogenetically related Candida species to the genera Kuraishia and Nakazawaea as new combinations.

    PubMed

    Kurtzman, Cletus P; Robnett, Christie J

    2014-11-01

    The new anamorphic yeast Kuraishia piskuri, f.a., sp. nov. is described for three strains that were isolated from insect frass from trees growing in Florida, USA (type strain, NRRL YB-2544, CBS 13714). Species placement was based on phylogenetic analysis of nuclear gene sequences for the D1/D2 domains of large subunit rRNA, small subunit rRNA, translation elongation factor-1α, and subunits B1 and B2 of RNA polymerase II B. From this analysis, the anamorphic species Candida borneana, Candida cidri, Candida floccosa, Candida hungarica, and Candida ogatae were transferred to the genus Kuraishia as new combinations and Candida anatomiae, Candida ernobii, Candida ishiwadae, Candida laoshanensis, Candida molendini-olei, Candida peltata, Candida pomicola, Candida populi, Candida wickerhamii, and Candida wyomingensis were transferred to the genus Nakazawaea. PMID:25132542

  12. Drosophila-associated yeast species in vineyard ecosystems.

    PubMed

    Lam, Samuel S T H; Howell, Kate S

    2015-10-01

    Yeast activity during wine fermentation directly contributes to wine quality, but the source and movement of yeasts in vineyards and winery environments have not been resolved. Here, we investigate the yeast species associated with the Drosophila insect vector to help understand yeast dispersal and persistence. Drosophila are commonly found in vineyards and are known to have a mutualistic relationship with yeasts in other ecosystems. Drosophilids were collected from vineyards, grape waste (marc) piles and wineries during grape harvest. Captured flies were identified morphologically, and their associated yeasts were identified. Drosophila melanogaster/D. simulans, D. hydei and Scaptodrosophila lativittata were identified in 296 captured Drosophila flies. These flies were associated with Metschnikowia pulcherrima, Hanseniaspora uvarum, Torulaspora delbrueckii and H. valbyensis yeasts. Yeast and Drosophila species diversity differed between collection locations (vineyard and marc: R = 0.588 for Drosophila and R = 0.644 for yeasts). Surprisingly, the primary wine fermentation yeast, Saccharomyces cerevisiae, was not isolated. Drosophila flies are preferentially associated with different yeast species in the vineyard and winery environments, and this association may help the movement and dispersal of yeast species in the vineyard and winery ecosystem. PMID:26391524

  13. Occultifur tropicalis f.a., sp. nov., a novel cystobasidiomycetous yeast species isolated from tropical regions.

    PubMed

    Khunnamwong, Pannida; Surussawadee, Janjira; Jindamorakot, Sasitorn; Ribeiro, José R A; Hagler, Allen N; Limtong, Savitree

    2015-05-01

    Five strains representing a single novel anamorphic yeast species were isolated from sugar cane. Two strains were from tissue (DMKU-SE38, DMKU-SE59(T)) and two from the external surface (DMKU-SP385, DMKU-SP403) of leaves collected in Thailand and the fifth (IMUFRJ 52020) from the rhizoplane of sugar cane in an organically cultivated field in Brazil. On the basis of sequence analysis of the D1/D2 region of the large subunit (LSU) rRNA gene and the internal transcribed spacer (ITS) region, they were classified as representing a single species of the genus Occultifur. The sequences of the D1/D2 region of the LSU rRNA genes and the ITS regions of the five strains were either identical or differed from each other by only one nucleotide substitution. The novel species was related most closely to Occultifur brasiliensis f.a. CBS 12687(T) but with 0.7-1.0% nucleotide substitutions (4-6 nt) in the D1/D2 region of the LSU rRNA gene and 2.5-2.7% nucleotide substitutions (14-15 nt) in the ITS region. The name Occultifur tropicalis f.a., sp. nov. is proposed. The type strain is DMKU-SE59(T) ( =BCC 61184(T) =NBRC 109696(T) =CBS 13389 (T)). PMID:25713048

  14. Glucosylation and other biotransformations of T-2 toxin by yeasts of the Trichomonascus clade

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Twenty-five yeasts assigned to the Trichomonascus clade (Saccharomycotina, Ascomycota), including three Trichomonascus species and 22 anamorphic species presently classified in Blastobotrys, were tested for their ability to convert T-2 toxin, a Fusarium trichothecene mycotoxin, to less toxic product...

  15. Recognition of Yeast Species from Gene Sequence Comparisons

    Technology Transfer Automated Retrieval System (TEKTRAN)

    This review discusses recognition of yeast species from gene sequence comparisons, which have been responsible for doubling the number of known yeasts over the past decade. The resolution provided by various single gene sequences is examined for both ascomycetous and basidiomycetous species, and th...

  16. THE PRACTICALITIES OF INTEGRATING ANAMORPH AND TELEOMORPH TAXONOMIES

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Article 59 of the International Code of Botanical Nomenclature enshrines a system that biases naming of pleomorphic fungi in favor of the teleomorph. The system maintains artificial separation of teleomorph and anamorph taxonomy resulting in loss of information and confusion in understanding species...

  17. Pleospora species with Stemphylium anamorphs: a four locus phylogeny resolves new lineages yet does not distinguish among species in the Pleospora herbarum clade.

    PubMed

    Inderbitzin, Patrik; Mehta, Yeshwant R; Berbee, Mary L

    2009-01-01

    Stemphylium is a genus of plant pathogens and saprobes in the Pleosporaceae (Pleosporales, Dothideomycetes, Ascomycetes). The teleomorphs of Stemphylium, where known, are in Pleospora, with Pleospora herbarum as the type. The goal of this study was to present a rigorous phylogenetic analysis of the relationships among Stemphylium isolates with particular emphasis on species delimitation in the P. herbarum clade, on possible new species and on the relationship of clades to cultures from type specimens. Our taxon sampling comprised 110 Stemphylium strains collected worldwide from various hosts and DNA sequences from four loci, from the ITS, the protein encoding GPD and EF-1 alpha genes and the intergenic spacer between vmaA and vpsA. A large EF-1 alpha intron delimited by noncanonical splice sites and encoding putative proteins was present in three unrelated isolates and was excluded from analyses. Isolates comprised 23 representatives derived from type strains, compared to type strains or otherwise connected to type material, 40 unnamed strains morphologically similar to the type P. herbarum, four strains from an outbreak of Stemphylium leaf blight of cotton in Brazil and eight strains collected in British Columbia mainly from nonagricultural hosts. Our findings provided strong support for the main groupings of Stemphylium obtained earlier and also revealed six possible new species. Other variation within morphological species might point to additional cryptic species. On the other hand, even with four loci, cultures ex-type of five species including P. herbarum were inseparable. We speculate that being self-fertile the clade including P. herbarum might represent a group of highly inbred, morphologically distinct lineages that have yet to accumulate detectable species-specific sequence variation. The lack of variation in P. herbarum clade contrasts with many other a priori defined morphological species where multigene phylogenetic analyses revealed new cryptic

  18. Isolation of Pseudozyma churashimaensis sp. nov., a novel ustilaginomycetous yeast species as a producer of glycolipid biosurfactants, mannosylerythritol lipids.

    PubMed

    Morita, Tomotake; Ogura, Yuki; Takashima, Masako; Hirose, Naoto; Fukuoka, Tokuma; Imura, Tomohiro; Kondo, Yukishige; Kitamoto, Dai

    2011-08-01

    An ustilaginomycetous anamorphic yeast species isolated from the leaves of Saccharum officinarum (sugarcane) in Okinawa, Japan, was identified as a novel Pseudozyma species based on morphological and physiological aspects and molecular taxonomic analysis using the D1/D2 domains of the large subunit (26S) rRNA gene and the internal transcribed spacer 1 (ITS1)-5.8S-ITS2 regions. The name Pseudozyma churashimaensis sp. nov. was proposed for the novel species, with JCM 16988(T) as the type strain. Interestingly, P. churashimaensis was found to produce glycolipid biosurfactants, a mixture of mannosylerythritol lipids (MELs), including a novel tri-acetylated derivative (MEL-A2), from glucose. The observed critical micelle concentration (CMC) and the surface tension at CMC of MEL-A2 were 1.7 × 10⁻⁶ M and 29.2 mN/m, respectively. Moreover, on a water-penetration scan, MEL-A2 efficiently formed different lyotropic liquid crystalline phases, including the lamella phase at a wide range of concentrations, indicating its excellent surface-active and self-assembling properties. The novel strain of the genus Pseudozyma should thus facilitate the application of glycolipid biosurfactants in combination with other MEL producers. PMID:21606002

  19. Species composition of Malassezia yeasts in dogs in Slovakia.

    PubMed

    Sihelská, Zuzana; Váczi, Peter; Conková, Eva

    2016-01-01

    Malassezia (M.) pachydermatis is the lipophilic yeast, which is normally present on the skin and in the ear canal of dogs but under certain conditions it may cause dermatitis and otitis. There is less known about the occurrence of lipid-dependent Malassezia species in dogs. The aim of this study was to detect whether lipid-dependent yeasts are part of the normal microflora in dogs. Two groups of animals were selected for comparison. The group of healthy dogs contained samples of 118 individuals and the group of dogs with cutaneous lesions or otitis externa comprised 328 dogs. The isolates of Malassezia were identified by using genotypic methods that allow the precise identification. M. pachydermatis was the most frequently isolated species in this study (121 isolates). Only four isolates were identified as M. furfur and one isolate was identified as M. nana. PMID:27529998

  20. Candida pseudorugosa sp. nov., a Novel Yeast Species from Sputum▿

    PubMed Central

    Li, Juan; Xu, Ying-Chun; Bai, Feng-Yan

    2006-01-01

    Two yeast strains, strains XH 1026 and XH 1164, isolated from the sputum of an intensive care unit patient with acute pneumonia, were originally identified as Candida albicans and C. tropicalis, respectively. Sequence analysis of the 26S rRNA gene D1/D2 domain and the internal transcribed spacer (ITS) region indicated that the two strains represent a novel yeast species closely related to C. rogusa. The name Candida pseudorugosa sp. nov. is therefore proposed (type strain, AS 2.3107 [CBS 10433]). The new species is able to grow at 42°C and is resistant or insusceptible to amphotericin B (MIC, 2 μg/ml), caspofungin (MIC, 64 μg/ml), itraconazole (MIC, 1 μg/ml), and nystatin (MIC, 16 μg/ml); dose-dependent susceptible to fluconazole (MIC, 16 μg/ml); and susceptible to flucytosine (MIC, 0.125 μg/ml) and voriconazole (MIC, 0.125 to 0.25 μg/ml). The code for C. pseudorugosa sp. nov. provided by the API 20C AUX system is identical to that for C. rugosa. The colonies of the new species on CHROMagar Candida appear blue-green, similar to those of C. albicans. In addition to the molecular method based on D1/D2 domain or ITS region sequencing, use of the combination of the API system and CHROMagar Candida is helpful for the correct identification of C. pseudorugosa sp. nov. PMID:17021068

  1. Candida spencermartinsiae sp. nov., Candida taylorii sp. nov. and Pseudozyma abaconensis sp. nov., novel yeasts from mangrove and coral reef ecosystems.

    PubMed

    Statzell-Tallman, Adele; Scorzetti, Gloria; Fell, Jack W

    2010-08-01

    Three species of yeasts are taxonomically described for strains isolated from marine environments. Candida spencermartinsiae sp. nov. (type strain CBS 10894T =NRRL Y-48663T) and Candida taylorii sp. nov. (type strain CBS 8508T =NRRL Y-27213T) are anamorphic ascomycetous yeasts in a phylogenetic cluster of marine yeasts in the Debaryomyces/Lodderomyces clade of the Saccharomycetales. The two species were isolated from multiple locations among coral reefs and mangrove habitats. Pseudozyma abaconensis sp. nov. (type strain CBS 8380T =NRRL Y-17380T) is an anamorphic basidiomycete that is related to the smut fungi of the genus Ustilago in the Ustilaginales. P. abaconensis was collected from waters adjacent to a coral reef. PMID:19783617

  2. Cryptococcus friedmannii, a new species of yeast from the Antarctic

    NASA Technical Reports Server (NTRS)

    Vishniac, H. S.

    1985-01-01

    Cryptococcus friedmannii Vishniac sp. nov. from an Antarctic cryptoendolithic community is a psychrophilic basidioblastomycete characterized by cream-colored colonies of cells with smooth, layered walls, budding monopolarly, producing amylose and extracellular proteinase, utilizing nitrate and D-alanine (inter alia) as nitrogen sources and L-arabinose, arbutin, cellobiose, D-glucuronate, maltose, melezitose, salicin, soluble starch, trehalose, and D-xylose as carbon sources. This species differs from all other basidiomycetous yeasts in possessing the following combination of characters: amylose production (positive), assimilation of cellobiose (positive), D-galactose (negative), myo-inositol (negative), D-mannitol (negative), and sucrose (negative).

  3. Rapid Identification of Candida Species and Other Clinically Important Yeast Species by Flow Cytometry†

    PubMed Central

    Page, Brent T.; Kurtzman, Cletus P.

    2005-01-01

    Two rapid diagnostic assays, utilizing two different Luminex flow cytometry methods, were developed for identification of clinically important ascomycetous yeast species. Direct hybridization and allele-specific primer extension methods were both successful in establishing a DNA-based assay that can rapidly and accurately identify Candida albicans, Candida krusei, Candida parapsilosis, Candida glabrata, and Candida tropicalis as well as other clinical species. The direct hybridization assay was designed to identify a total of 19 ascomycetous yeast species, and the allele-specific primer extension assay was designed to identify a total of 34 species. Probes were validated against 438 strains representing 303 species. From culture to identification, the allele-specific primer extension method takes 8 h and the direct hybridization method takes less than 5 h to complete. These assays represent comprehensive, rapid tests that are well suited for the clinical laboratory. PMID:16145099

  4. Evolution of Phosphoregulation: Comparison of Phosphorylation Patterns across Yeast Species

    PubMed Central

    Beltrao, Pedro; Trinidad, Jonathan C.; Fiedler, Dorothea; Roguev, Assen; Lim, Wendell A.; Shokat, Kevan M.; Burlingame, Alma L.; Krogan, Nevan J.

    2009-01-01

    The extent by which different cellular components generate phenotypic diversity is an ongoing debate in evolutionary biology that is yet to be addressed by quantitative comparative studies. We conducted an in vivo mass-spectrometry study of the phosphoproteomes of three yeast species (Saccharomyces cerevisiae, Candida albicans, and Schizosaccharomyces pombe) in order to quantify the evolutionary rate of change of phosphorylation. We estimate that kinase–substrate interactions change, at most, two orders of magnitude more slowly than transcription factor (TF)–promoter interactions. Our computational analysis linking kinases to putative substrates recapitulates known phosphoregulation events and provides putative evolutionary histories for the kinase regulation of protein complexes across 11 yeast species. To validate these trends, we used the E-MAP approach to analyze over 2,000 quantitative genetic interactions in S. cerevisiae and Sc. pombe, which demonstrated that protein kinases, and to a greater extent TFs, show lower than average conservation of genetic interactions. We propose therefore that protein kinases are an important source of phenotypic diversity. PMID:19547744

  5. Raman Spectroscopy and Chemometrics for Identification and Strain Discrimination of the Wine Spoilage Yeasts Saccharomyces cerevisiae, Zygosaccharomyces bailii, and Brettanomyces bruxellensis

    PubMed Central

    Thornton, Mark A.; Thornton, Roy J.

    2013-01-01

    The yeasts Zygosaccharomyces bailii, Dekkera bruxellensis (anamorph, Brettanomyces bruxellensis), and Saccharomyces cerevisiae are the major spoilage agents of finished wine. A novel method using Raman spectroscopy in combination with a chemometric classification tool has been developed for the identification of these yeast species and for strain discrimination of these yeasts. Raman spectra were collected for six strains of each of the yeasts Z. bailii, B. bruxellensis, and S. cerevisiae. The yeasts were classified with high sensitivity at the species level: 93.8% for Z. bailii, 92.3% for B. bruxellensis, and 98.6% for S. cerevisiae. Furthermore, we have demonstrated that it is possible to discriminate between strains of these species. These yeasts were classified at the strain level with an overall accuracy of 81.8%. PMID:23913433

  6. Anamorphic Imaging with Three Mirrors: A Survey

    NASA Technical Reports Server (NTRS)

    Howard, Joseph M.; Stone, Bryan D.

    2010-01-01

    Design methods are described for unobstructed, plane-symmetric, anamorphic systems composed of three mirrors. Low order imaging constraints are used to reduce the dimensionality of the configuration space. Examples are presented from a specific class of systems with fixed packaging constraints.

  7. Cyberlindnera xylolytica sp. nov., a xylitol-producing yeast species isolated from lignocellulosic materials

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Independent surveys of yeasts associated with lignocellulosic-related materials led to the discovery of a novel yeast species belonging to the Cyberlindnera clade (Saccharomycotina, Ascomycota). Analysis of the sequences of the internal transcribed spacer (ITS) region and the D1/D2 domains of the la...

  8. Carbon source utilization and inhibitor tolerance of 45 oleaginous yeast species

    PubMed Central

    Sitepu, Irnayuli; Selby, Tylan; Lin, Ting; Zhu, Shirley; Boundy-Mills, Kyria

    2014-01-01

    Conversion of lignocellulosic hydrolysates to lipids using oleaginous (high lipid) yeasts requires alignment of the hydrolysate composition with the characteristics of the yeast strain, including ability to utilize certain nutrients, ability to grow independently of costly nutrients such as vitamins, and ability to tolerate inhibitors. Some combination of these characteristics may be present in wild strains. In this study, 48 oleaginous yeast strains belonging to 45 species were tested for ability to utilize carbon sources associated with lignocellulosic hydrolysates, tolerate inhibitors, and grow in medium without supplemented vitamins. Some well-studied oleaginous yeast species, as well as some that have not been frequently utilized in research or industrial production, emerged as promising candidates for industrial use due to ability to utilize many carbon sources, including Cryptococcus aureus, Cryptococcus laurentii, Hanaella aff. zeae, Tremella encephala, and Trichosporon coremiiforme. Other species excelled in inhibitor tolerance, including Candida aff. tropicalis, Cyberlindnera jadinii, Metschnikowia pulcherrima Schwanniomyces occidentalis and Wickerhamomyces ciferii. No yeast tested could utilize all carbon sources and tolerate all inhibitors tested. These results indicate that yeast strains should be selected based on characteristics compatible with the composition of the targeted hydrolysate. Other factors to consider include the production of valuable co-products such as carotenoids, availability of genetic tools, biosafety level, and flocculation of the yeast strain. The data generated in this study will aid in aligning yeasts with compatible hydrolysates for conversion of carbohydrates to lipids to be used for biofuels and other oleochemicals. PMID:24818698

  9. Delimitation of Neonectria and Cylindrocarpon (Nectriaceae, Hypocreales, Ascomycota) and related genera with Cylindrocarpon-like anamorphs.

    PubMed

    Chaverri, P; Salgado, C; Hirooka, Y; Rossman, A Y; Samuels, G J

    2011-01-01

    Neonectria is a cosmopolitan genus and it is, in part, defined by its link to the anamorph genus Cylindrocarpon. Neonectria has been divided into informal groups on the basis of combined morphology of anamorph and teleomorph. Previously, Cylindrocarpon was divided into four groups defined by presence or absence of microconidia and chlamydospores. Molecular phylogenetic analyses have indicated that Neonectriasensu stricto and Cylindrocarponsensu stricto are phylogenetically congeneric. In addition, morphological and molecular data accumulated over several years have indicated that Neonectria sensu lato and Cylindrocarponsensu lato do not form a monophyletic group and that the respective informal groups may represent distinct genera. In the present work, a multilocus analysis (act, ITS, LSU, rpb1, tef1, tub) was applied to representatives of the informal groups to determine their level of phylogenetic support as a first step towards taxonomic revision of Neonectriasensu lato. Results show five distinct highly supported clades that correspond to some extent with the informal Neonectria and Cylindrocarpon groups that are here recognised as genera: (1) N. coccinea-group and Cylindrocarpon groups 1 & 4 (Neonectria/Cylindrocarponsensu stricto); (2) N.rugulosa-group (Rugonectria gen. nov.); (3) N. mammoidea/N. veuillotiana-groups and Cylindrocarpon group 2 (Thelonectria gen. nov.); (4) N. radicicola-group and Cylindrocarpon group 3 (Ilyonectria gen. nov.); and (5) anamorph genus Campylocarpon. Characteristics of the anamorphs and teleomorphs correlate with the five genera, three of which are newly described. New combinations are made for species where their classification is confirmed by phylogenetic data. PMID:21523189

  10. Compact Reflective Imaging Spectrometer Design Utilizing An Immersed Grating And Anamorphic Mirror

    DOEpatents

    Lerner, Scott A.

    2006-01-10

    A compact imaging spectrometer comprising an entrance slit, an anamorphic mirror, a grating, and a detector array. The entrance slit directs light to the anamorphic mirror. The anamorphic mirror receives the light and directs the light to the grating. The grating receives the light from the anamorphic mirror and defracts the light back onto the anamorphic mirror. The anamorphic mirror focuses the light onto a detector array.

  11. Barcode Identifiers as a Practical Tool for Reliable Species Assignment of Medically Important Black Yeast Species

    PubMed Central

    Heinrichs, Guido; de Hoog, G. Sybren

    2012-01-01

    Herpotrichiellaceous black yeasts and relatives comprise severe pathogens flanked by nonpathogenic environmental siblings. Reliable identification by conventional methods is notoriously difficult. Molecular identification is hampered by the sequence variability in the internal transcribed spacer (ITS) domain caused by difficult-to-sequence homopolymeric regions and by poor taxonomic attribution of sequences deposited in GenBank. Here, we present a potential solution using short barcode identifiers (27 to 50 bp) based on ITS2 ribosomal DNA (rDNA), which allows unambiguous definition of species-specific fragments. Starting from proven sequences of ex-type and authentic strains, we were able to describe 103 identifiers. Multiple BLAST searches of these proposed barcode identifiers in GenBank revealed uniqueness for 100 taxonomic entities, whereas the three remaining identifiers each matched with two entities, but the species of these identifiers could easily be discriminated by differences in the remaining ITS regions. Using the proposed barcode identifiers, a 4.1-fold increase of 100% matches in GenBank was achieved in comparison to the classical approach using the complete ITS sequences. The proposed barcode identifiers will be made accessible for the diagnostic laboratory in a permanently updated online database, thereby providing a highly practical, reliable, and cost-effective tool for identification of clinically important black yeasts and relatives. PMID:22785187

  12. A survey of yeasts in traditional sausages of southern Italy.

    PubMed

    Gardini, F; Suzzi, G; Lombardi, A; Galgano, F; Crudele, M A; Andrighetto, C; Schirone, M; Tofalo, R

    2001-07-01

    The evolution of the yeast population during manufacturing and ripening of 'salsiccia sotto sugna', a typical salami of the Lucania region (southern Italy), was investigated. Four different batches, produced in four farms in Lucania, were studied. Each batch showed a specific yeast population, and the most frequently isolated yeasts belonged to Debaryomyces hansenii and its anamorph Candida famata, and Rhodotorula mucilaginosa. Yarrowia lipolytica was isolated from three sausage batches. The Y. lipolytica isolates were further characterised, in particular for their lipolytic activity on pork fat. Lipolytic activity was maximal at pH 5.5, with oleic and palmitic acids as major free fatty acids produced. The use of randomly amplified polymorphic DNA-polymerase chain reaction allowed the detection of a high genetic heterogeneity among the isolates phenotypically assigned to the species Y. lipolytica. PMID:12702361

  13. Species level identification and antifungal susceptibility of yeasts isolated from various clinical specimens and evaluation of Integral System Yeasts Plus.

    PubMed

    Bicmen, Can; Doluca, Mine; Gulat, Sinem; Gunduz, Ayriz T; Tuksavul, Fevziye

    2012-07-01

    It is essential to use easy, standard, cost-effective and accurate methods for identification and susceptibility testing of yeasts in routine practice. This study aimed to establish the species distribution and antifungal susceptibility of yeast isolates and also to evaluate the performance of the colorimetric and commercially available Integral System Yeasts Plus (ISYP). Yeast isolates (n=116) were identified by conventional methods and ISYP. Antifungal susceptibility testing was performed by the microdilution method according to the standards of CLSI M27-A3 and ISYP. Candida albicans (50%) was the most common species isolated, followed by C. parapsilosis (25%) (mostly in blood samples). According to the CLSI M27-S3 criteria, resistance rates for amphotericin B, flucytosine, fluconazole, itraconazole, and voriconazole were 0%, 0%, 4.6%, 4.5% and 1.8%, respectively. Resistance for miconazole (MIC >1 mg/L) was found as 17.9%. Sixty-two (53.4%) of the isolates which were analyzed by ISYP showed disagreement with those identified by the conventional methods and API ID 32C identification kit or a specific identification code could not be assigned by ISYP. The performance of ISYP could be indicated as low for all antifungal drugs tested according to the ROC analysis (AUC: 0.28-0.56). As the current version of ISYP displays a poor performance, it is recommended to use the other commercial systems whose results are approved as reliable and in agreement with those of the reference methods in identification and susceptibility testing of yeasts. PMID:22842602

  14. Genetically modified yeast species and fermentation processes using genetically modified yeast

    SciTech Connect

    Rajgarhia, Vineet; Koivuranta, Kari; Penttila, Merja; Ilmen, Marja; Suominen, Pirkko; Aristidou, Aristos; Miller, Christopher Kenneth; Olson, Stacey; Ruohonen, Laura

    2011-05-17

    Yeast cells are transformed with an exogenous xylose isomerase gene. Additional genetic modifications enhance the ability of the transformed cells to ferment xylose to ethanol or other desired fermentation products. Those modifications', include deletion of non-specific or specific aldose reductase gene(s), deletion of xylitol dehydrogenase gene(s) and/or overexpression of xylulokinase.

  15. Genetically modified yeast species, and fermentation processes using genetically modified yeast

    SciTech Connect

    Rajgarhia, Vineet; Koivuranta, Kari; Penttila, Merja; Ilmen, Marja; Suominen, Pirkko; Aristidou, Aristos; Miller, Christopher Kenneth; Olson, Stacey; Ruohonen, Laura

    2014-01-07

    Yeast cells are transformed with an exogenous xylose isomerase gene. Additional genetic modifications enhance the ability of the transformed cells to ferment xylose to ethanol or other desired fermentation products. Those modifications include deletion of non-specific aldose reductase gene(s), deletion of xylitol dehydrogenase gene(s) and/or overexpression of xylulokinase.

  16. Genetically modified yeast species, and fermentation processes using genetically modified yeast

    SciTech Connect

    Rajgarhia, Vineet; Koivuranta, Kari; Penttila, Merja; Ilmen, Marja; Suominen, Pirkko; Aristidou, Aristos; Miller, Christopher Kenneth; Olson, Stacey; Ruohonen, Laura

    2013-05-14

    Yeast cells are transformed with an exogenous xylose isomerase gene. Additional genetic modifications enhance the ability of the transformed cells to ferment xylose to ethanol or other desired fermentation products. Those modifications include deletion of non-specific or specific aldose reductase gene(s), deletion of xylitol dehydrogenase gene(s) and/or overexpression of xylulokinase.

  17. Genetically modified yeast species, and fermentation processes using genetically modified yeast

    DOEpatents

    Rajgarhia, Vineet; Koivuranta, Kari; Penttila, Merja; Ilmen, Marja; Suominen, Pirkko; Aristidou, Aristos; Miller, Christopher Kenneth; Olson, Stacey; Ruohonen, Laura

    2016-08-09

    Yeast cells are transformed with an exogenous xylose isomerase gene. Additional genetic modifications enhance the ability of the transformed cells to ferment xylose to ethanol or other desired fermentation products. Those modifications include deletion of non-specific or specific aldose reductase gene(s), deletion of xylitol dehydrogenase gene(s) and/or overexpression of xylulokinase.

  18. A monograph of the entomopathogenic genera Hypocrella, Moelleriella, and Samuelsia gen. nov. (Ascomycota, Hypocreales, Clavicipitaceae), and their aschersonia-like anamorphs in the Neotropics

    PubMed Central

    Chaverri, P.; Liu, M.; Hodge, K.T.

    2008-01-01

    The present taxonomic revision deals with Neotropical species of three entomopathogenic genera that were once included in Hypocrella s. l.: Hypocrella s. str. (anamorph Aschersonia), Moelleriella (anamorph aschersonia-like), and Samuelsia gen. nov (anamorph aschersonia-like). Species of Hypocrella, Moelleriella, and Samuelsia are pathogens of scale insects (Coccidae and Lecaniidae, Homoptera) and whiteflies (Aleyrodidae, Homoptera) and are common in tropical regions. Phylogenetic analyses of DNA sequences from nuclear ribosomal large subunit (28S), translation elongation factor 1-α (TEF 1-α), and RNA polymerase II subunit 1 (RPB1) and analyses of multiple morphological characters demonstrate that the three segregated genera can be distinguished by the disarticulation of the ascospores and shape and size of conidia. Moelleriella has filiform multi-septate ascospores that disarticulate at the septa within the ascus and aschersonia-like anamorphs with fusoid conidia. Hypocrella s. str. has filiform to long-fusiform ascospores that do not disarticulate and Aschersonia s. str. anamorphs with fusoid conidia. The new genus proposed here, Samuelsia, has filiform to long-fusiform ascospores that do not disarticulate and aschersonia-like anamorphs with small allantoid conidia. In addition, the present study presents and discusses the evolution of species, morphology, and ecology in Hypocrella, Moelleriella, and Samuelsia based on multigene phylogenetic analyses. PMID:18490956

  19. Genetically modified yeast of the species Issatchenkia orientalis and closely relates species, and fermentation processes using same

    SciTech Connect

    Suominen, Pirkko; Aristidou, Aristos; Pentilla, Merja; Ilmen, Marja; Ruohonen, Laura; Koivuranta, Kari; Roberg-Perez, Kevin

    2012-01-17

    Cells of the species Issatchenkia orientalis and closely related yeast species are transformed with a vector to introduce an exogenous lactate dehydrogenase gene. The cells produce lactic acid efficiently and are resistant at low pH, high lactate titer conditions.

  20. Species identification of invasive yeasts including Candida in Pakistan: limitations of phenotypic methods

    PubMed Central

    Farooqi, Joveria; Jabeen, Kauser; Saeed, Noureen; Zafar, Afia; Brandt, Mary Eleanor; Hasan, Rumina

    2015-01-01

    Objective To compare phenotypic and genotypic methods of yeast identification. Methods The in-vitro cross-sectional study was conducted from January 2006 to May 2009. Invasive yeasts isolated at the clinical microbiology laboratory at the Aga Khan University (AKU), Karachi, Pakistan, were identified. Speciation by phenotypic and molecular methods was compared. All yeasts isolated during the study period from blood and other invasive sites were identified using standard methods. Isolates were shipped to Mycotic Diseases Branch, Centres for Disease Control and Prevention, Atlanta, Georgia, USA, for identification by Luminex flow cytometric multianalyte profiling (xMAP) system. Ribosomal ITS2 DNA sequencing was performed on isolates not identified by Luminex. Result Of the 214 invasive yeasts evaluated, Candida species were 209 (97.7%) while the frequency of non-Candida species was 5 (2.3%). Overall agreement between phenotypic and molecular identification was 81.3%, 90.3% amongst the more common Candida species, and only 38.8% amongst the uncommon yeasts. Conclusion Phenotypic methods of identification proved adequate for common Candida species, but were deficient in recognising rare Candida and non-Candida yeasts, highlighting the importance of molecular methods for identification. PMID:23866432

  1. Phylogeny and systematics of the anamorphic, entomopathogenic genus Beauveria.

    PubMed

    Rehner, Stephen A; Minnis, Andrew M; Sung, Gi-Ho; Luangsa-ard, J Jennifer; Devotto, Luis; Humber, Richard A

    2011-01-01

    Beauveria is a cosmopolitan anamorphic genus of arthropod pathogens that includes the agronomically important species, B. bassiana and B. brongniartii, which are used as mycoinsecticides for the biological control of pest insects. Recent phylogenetic evidence demonstrates that Beauveria is monophyletic within the Cordycipitaceae (Hypocreales), and both B. bassiana and B. brongniartii have been linked developmentally and phylogenetically to Cordyceps species. Despite recent interest in the genetic diversity and molecular ecology of Beauveria, particularly as it relates to their role as pathogens of insects in natural and agricultural environments, the genus has not received critical taxonomic review for several decades. A multilocus phylogeny of Beauveria based on partial sequences of RPB1, RPB2, TEF and the nuclear intergenic region, Bloc, is presented and used to assess diversity within the genus and to evaluate species concepts and their taxonomic status. B. bassiana and B. brongniartii, both which represent species complexes and which heretofore have lacked type specimens, are redescribed and types are proposed. In addition six new species are described including B. varroae and B. kipukae, which form a biphyletic, morphologically cryptic sister lineage to B. bassiana, B. pseudobassiana, which also is morphologically similar to but phylogenetically distant from B. bassiana, B. asiatica and B. australis, which are sister lineages to B. brongniartii, and B. sungii, an Asian species that is linked to an undetermined species of Cordyceps. The combination B. amorpha is validly published and an epitype is designated. PMID:21482632

  2. Evaluation of Different Yeast Species for Improving In vitro Fermentation of Cereal Straws

    PubMed Central

    Wang, Zuo; He, Zhixiong; Beauchemin, Karen A.; Tang, Shaoxun; Zhou, Chuanshe; Han, Xuefeng; Wang, Min; Kang, Jinhe; Odongo, Nicholas E.; Tan, Zhiliang

    2016-01-01

    Information on the effects of different yeast species on ruminal fermentation is limited. This experiment was conducted in a 3×4 factorial arrangement to explore and compare the effects of addition of three different live yeast species (Candida utilis 1314, Saccharomyces cerevisiae 1355, and Candida tropicalis 1254) at four doses (0, 0.25×107, 0.50×107, and 0.75×107 colony-forming unit [cfu]) on in vitro gas production kinetics, fiber degradation, methane production and ruminal fermentation characteristics of maize stover, and rice straw by mixed rumen microorganisms in dairy cows. The maximum gas production (Vf), dry matter disappearance (IVDMD), neutral detergent fiber disappearance (IVNDFD), and methane production in C. utilis group were less (p<0.01) than other two live yeast supplemented groups. The inclusion of S. cerevisiae reduced (p<0.01) the concentrations of ammonia nitrogen (NH3-N), isobutyrate, and isovalerate compared to the other two yeast groups. C. tropicalis addition generally enhanced (p<0.05) IVDMD and IVNDFD. The NH3-N concentration and CH4 production were increased (p<0.05) by the addition of S. cerevisiae and C. tropicalis compared with the control. Supplementation of three yeast species decreased (p<0.05) or numerically decreased the ratio of acetate to propionate. The current results indicate that C. tropicalis is more preferred as yeast culture supplements, and its optimal dose should be 0.25×107 cfu/500 mg substrates in vitro. PMID:26732448

  3. Production of sophorolipids biosurfactants by multiple species of the Starmerella (Candida) bombicola yeast clade

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Sophorolipid production was tested for 26 strains representing 19 species of the Starmerella yeast clade, including S. bombicola and Candida apicola, which were previously reported to produce sophorolipids. Five of the 19 species tested showed significant production of sophorolipids: S. bombicola, ...

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

    PubMed

    Čadež, Neža; Fülöp, László; Dlauchy, Dénes; Péter, Gábor

    2015-03-01

    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.01994(T) = CBS 13653(T) = NRRL Y-63719(T) = ZIM 2551(T)) 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. PMID:25528339

  5. Phylogeny and taxonomic revision of the Planistromellaceae including its coelomycetous anamorphs: contributions towards a monograph of the genus Kellermania

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The core species of the family Planistromellaceae are included in the teleomorphic genera Planistroma and Planistromella and their anamorphic, coelomycetous genera Alpakesa, Kellermania, and Piptarthron. These genera have been defined primarily on the basis of ascospore septation or number of conidi...

  6. Non-conventional Yeast Species for Lowering Ethanol Content of Wines

    PubMed Central

    Ciani, Maurizio; Morales, Pilar; Comitini, Francesca; Tronchoni, Jordi; Canonico, Laura; Curiel, José A.; Oro, Lucia; Rodrigues, Alda J.; Gonzalez, Ramon

    2016-01-01

    Rising sugar content in grape must, and the concomitant increase in alcohol levels in wine, are some of the main challenges affecting the winemaking industry nowadays. Among the several alternative solutions currently under study, the use of non-conventional yeasts during fermentation holds good promise for contributing to relieve this problem. Non-Saccharomyces wine yeast species comprise a high number or species, so encompassing a wider physiological diversity than Saccharomyces cerevisiae. Indeed, the current oenological interest of these microorganisms was initially triggered by their potential positive contribution to the sensorial complexity of quality wines, through the production of aroma and other sensory-active compounds. This diversity also involves ethanol yield on sugar, one of the most invariant metabolic traits of S. cerevisiae. This review gathers recent research on non-Saccharomyces yeasts, aiming to produce wines with lower alcohol content than those from pure Saccharomyces starters. Critical aspects discussed include the selection of suitable yeast strains (considering there is a noticeable intra-species diversity for ethanol yield, as shown for other fermentation traits), identification of key environmental parameters influencing ethanol yields (including the use of controlled oxygenation conditions), and managing mixed fermentations, by either the sequential or simultaneous inoculation of S. cerevisiae and non-Saccharomyces starter cultures. The feasibility, at the industrial level, of using non-Saccharomyces yeasts for reducing alcohol levels in wine will require an improved understanding of the metabolism of these alternative yeast species, as well as of the interactions between different yeast starters during the fermentation of grape must. PMID:27199967

  7. Non-conventional Yeast Species for Lowering Ethanol Content of Wines.

    PubMed

    Ciani, Maurizio; Morales, Pilar; Comitini, Francesca; Tronchoni, Jordi; Canonico, Laura; Curiel, José A; Oro, Lucia; Rodrigues, Alda J; Gonzalez, Ramon

    2016-01-01

    Rising sugar content in grape must, and the concomitant increase in alcohol levels in wine, are some of the main challenges affecting the winemaking industry nowadays. Among the several alternative solutions currently under study, the use of non-conventional yeasts during fermentation holds good promise for contributing to relieve this problem. Non-Saccharomyces wine yeast species comprise a high number or species, so encompassing a wider physiological diversity than Saccharomyces cerevisiae. Indeed, the current oenological interest of these microorganisms was initially triggered by their potential positive contribution to the sensorial complexity of quality wines, through the production of aroma and other sensory-active compounds. This diversity also involves ethanol yield on sugar, one of the most invariant metabolic traits of S. cerevisiae. This review gathers recent research on non-Saccharomyces yeasts, aiming to produce wines with lower alcohol content than those from pure Saccharomyces starters. Critical aspects discussed include the selection of suitable yeast strains (considering there is a noticeable intra-species diversity for ethanol yield, as shown for other fermentation traits), identification of key environmental parameters influencing ethanol yields (including the use of controlled oxygenation conditions), and managing mixed fermentations, by either the sequential or simultaneous inoculation of S. cerevisiae and non-Saccharomyces starter cultures. The feasibility, at the industrial level, of using non-Saccharomyces yeasts for reducing alcohol levels in wine will require an improved understanding of the metabolism of these alternative yeast species, as well as of the interactions between different yeast starters during the fermentation of grape must. PMID:27199967

  8. Emulation of anamorphic imaging on the SHARP EUV mask microscope

    NASA Astrophysics Data System (ADS)

    Benk, Markus P.; Wojdyla, Antoine; Chao, Weilun; Salmassi, Farhad; Oh, Sharon; Wang, Yow-Gwo; Miyakawa, Ryan H.; Naulleau, Patrick P.; Goldberg, Kenneth A.

    2016-03-01

    The SHARP High numerical aperture Actinic Reticle review Project is a synchrotron-based, extreme ultraviolet (EUV) microscope dedicated to photomask research. SHARP emulates the illumination and imaging conditions of current EUV lithography scanners and several generations into the future. An anamorphic imaging optic with increased mask side-NA in the horizontal and increased demagnification in the vertical direction has been proposed to overcome limitations of current multilayer coatings and extend EUV lithography beyond 0.33 NA.1 Zoneplate lenses with an anamorphic 4x/8x NA of 0.55 are fabricated and installed in the SHARP microscope to emulate anamorphic imaging. SHARP's Fourier synthesis illuminator with a range of angles exceeding the collected solid angle of the newly designed elliptical zoneplates can produce arbitrary angular source spectra, matched to anamorphic imaging. A target with anamorphic dense features down to 50-nm critical dimension is fabricated using 40-nm of nickel as the absorber. In a demonstration experiment anamorphic imaging at 0.55 4x/8xNA and 6° central ray angle is compared to conventional imaging at 0.5 4xNA and 8° central ray angle. A significant contrast loss in horizontal features is observed in the conventional images. The anamorphic images show the same image quality in the horizontal and vertical directions.

  9. [Isolated yeast species in urine samples in a Spanish regional hospital].

    PubMed

    Heras-Cañas, Victor; Ros, Luis; Sorlózano, Antonio; Gutiérrez-Soto, Blanca; Navarro-Marí, José María; Gutiérrez-Fernández, José

    2015-01-01

    Candiduria detection in hospitalized or immunocompromised patients is of great clinical significance. The aim of our study was to describe the isolation frequency of significant species of yeasts in urine samples processed in our hospital during the period 2010- 2013, and to analyze their susceptibility to commonly used antifungal agents. Species identification was performed by seeding on a chromogenic medium, the filamentation test and automated systems (ASM Vitek and MALDI Biotyper), while susceptibility was determined using the ASM Vitek system. Of the 632 yeast isolates in urine, 371 were Candida albicans species and 261 non-C. albicans Candida spp. The species with the highest number of resistant isolates were Candida glabrata and Candida krusei. Based on the results obtained, we believe that species identification and the susceptibility study should be current practice in the laboratories when species other than C. albicans are isolated. PMID:26507634

  10. Two yeast species Cystobasidium psychroaquaticum f.a. sp. nov. and Cystobasidium rietchieii f.a. sp. nov. isolated from natural environments, and the transfer of Rhodotorula minuta clade members to the genus Cystobasidium.

    PubMed

    Yurkov, A M; Kachalkin, A V; Daniel, H M; Groenewald, M; Libkind, D; de Garcia, V; Zalar, P; Gouliamova, D E; Boekhout, T; Begerow, D

    2015-01-01

    Many species of dimorphic basidiomycetes are known only in their asexual phase and typically those pigmented in different hues of red have been classified in the large polyphyletic genus Rhodotorula. These yeasts are ubiquitous and include a few species of some clinical relevance. The phylogenetic distribution of Rhodotorula spans three classes: Microbotryomycetes, Cystobasidiomycetes and Exobasidiomycetes. Here, the presented multi-gene analyses resolved phylogenetic relationships between the second largest group of Rhodotorula and the mycoparasite Cystobasidium fimetarium (Cystobasidiales, Cystobasidiomycetes, Pucciniomycotina). Based on the results, we propose the transfer of nine species belonging to the Rhodotorula minuta clade into the genus Cystobasidium. As a result, the clinically relevant species R. minuta will be renamed Cystobasidium minutum. This proposal follows ongoing reassessments of the anamorphic genus Rhodotorula reducing the polyphyly of this genus. The delimitation of the R. minuta clade from Rhodotorula species comprised in Sporidiobolales including the type species Rhodotorula glutinis is an important step to overcome obsolete generic placements of asexual basidiomycetous yeasts. Our proposal will also help to distinguish most common red yeasts from clinical samples such as members of Sporidiobolales and Cystobasidiales. The diagnosis of the genus Cystobasidium is amended by including additional characteristics known for the related group of species. The taxonomic change enables us to classify two novel species with the phylogenetically related members of the R. minuta clade in Cystobasidium. The recently from natural environments isolated species are described here as Cystobasidium psychroaquaticum f.a. sp. nov. (K-833(T) = KBP 3881(T) = VKPM Y-3653(T) = CBS 11769(T) = MUCL 52875(T) = DSM 27713(T)) and Cystobasidium rietchiei f.a. sp. nov. (K-780(T) = KBP 4220(T) = VKPM Y-3658(T) = CBS 12324(T) = MUCL 53589(T

  11. Biotransformation of volatile fatty acids by oleaginous and non-oleaginous yeast species.

    PubMed

    Kolouchová, Irena; Schreiberová, Olga; Sigler, Karel; Masák, Jan; Řezanka, Tomáš

    2015-11-01

    The possibility of utilizing volatile fatty acids (VFA)-containing waste substrates from biotechnological and industrial processes was investigated by cultivating both oleaginous (Candida sp., Rhodotorula glutinis, Trichosporon cutaneum, Yarrowia lipolytica) and non-oleaginous (Kluyveromyces polysporus, Saccharomyces cerevisiae, Torulaspora delbrueckii) yeast species on acetic acid, propionic acid and a combination of either acid with glucose as carbon and energy sources. Both oleaginous and non-oleaginous yeasts grew on VFA. Oleaginous yeasts accumulated lipids to 15-48% of dry cell weight, non-oleaginous yeasts also grew on VFA and showed comparable biomass yields but the lipid content was only 2-5%. Biomass and lipid yield increased in cultivations on VFA plus glucose. The lipid composition was comparable to plant-derived oils and therefore might be exploitable in biodiesel production; nearly all species, when cultured on propionate, showed a high content of the desirable odd-chain unsaturated FA, especially 17:1 acid. This study points at the wide array of possible applications of many yeasts, even non-oleaginous strains, for biovalorization of industrial wastes. Despite their low lipid content these species are useful because they can readily utilize VFA from waste products and, since they are not biologically hazardous, their biomass can be afterwards used, e.g. as livestock fodder. PMID:26323601

  12. Evolution of ecological dominance of yeast species in high-sugar environments

    PubMed Central

    Williams, Kathryn M.; Liu, Ping; Fay, Justin C.

    2016-01-01

    In budding yeasts, fermentation in the presence of oxygen evolved around the time of a whole genome duplication (WGD) and is thought to confer dominance in high-sugar environments because ethanol is toxic to many species. While there are many fermentative yeast species, only Saccharomyces cerevisiae consistently dominates wine fermentations. In this study, we use co-culture experiments and intrinsic growth rate assays to examine the relative fitness of non-WGD and WGD yeast species across environments to assess when S. cerevisiae’s ability to dominate high-sugar environments arose. We show that S. cerevisiae dominates nearly all other non-WGD and WGD species except for its sibling species S. paradoxus in both grape juice and a high-sugar rich medium. Of the species we tested, S. cerevisiae and S. paradoxus have evolved the highest ethanol tolerance and intrinsic growth rate in grape juice. However, the ability of S. cerevisiae and S. paradoxus to dominate certain species depends on the temperature and the type of high-sugar environment. Our results indicate that dominance of high-sugar environments evolved much more recently than the WGD, most likely just prior to or during the differentiation of Saccharomyces species, and that evolution of multiple traits contributes to S. cerevisiae’s ability to dominate wine fermentations. PMID:26087012

  13. Evolution of ecological dominance of yeast species in high-sugar environments.

    PubMed

    Williams, Kathryn M; Liu, Ping; Fay, Justin C

    2015-08-01

    In budding yeasts, fermentation in the presence of oxygen evolved around the time of a whole genome duplication (WGD) and is thought to confer dominance in high-sugar environments because ethanol is toxic to many species. Although there are many fermentative yeast species, only Saccharomyces cerevisiae consistently dominates wine fermentations. In this study, we use coculture experiments and intrinsic growth rate assays to examine the relative fitness of non-WGD and WGD yeast species across environments to assess when S. cerevisiae's ability to dominate high-sugar environments arose. We show that S. cerevisiae dominates nearly all other non-WGD and WGD species except for its sibling species S. paradoxus in both grape juice and a high-sugar rich medium. Of the species we tested, S. cerevisiae and S. paradoxus have evolved the highest ethanol tolerance and intrinsic growth rate in grape juice. However, the ability of S. cerevisiae and S. paradoxus to dominate certain species depends on the temperature and the type of high-sugar environment. Our results indicate that dominance of high-sugar environments evolved much more recently than the WGD, most likely just prior to or during the differentiation of Saccharomyces species, and that evolution of multiple traits contributes to S. cerevisiae's ability to dominate wine fermentations. PMID:26087012

  14. Occurrence and dominance of yeast species in naturally fermented milk from the Tibetan Plateau of China.

    PubMed

    Bai, Mei; Qing, Manjun; Guo, Zhuang; Zhang, Yong; Chen, Xia; Bao, Qiuhua; Zhang, Heping; Sun, Tian-Song

    2010-09-01

    To determine which yeasts are present in the naturally fermented milks of China, 69 samples made by the nomads of Tibet were collected from the Tibetan Plateau in China. From these samples, 225 strains of yeast were isolated and identified using conventional microbiological analysis and gene sequencing analysis of the D1/D2 domain of the large subunit (26S) ribosomal DNA. The results showed that the total concentration of yeasts in these samples ranged from 5.01 to 8.97 log10 colony-forming units (CFU)/mL (6.91 ± 1.02 log10 CFU/mL; mean ± SD). The number of cultivable yeasts was higher in the samples from Qinghai (7.55 ± 0.75 log10 CFU/mL) than those from Tibet (6.21 ± 0.79 log10 CFU/mL, P < 0.05). Moreover, there were 15 phylotypes in these 69 samples. Among these phylotypes, Kluyveromyces marxianus (49.3%, frequency percentage), Saccharomyces cerevisiae (62.3%), and Pichia fermentans (46.4%) appeared frequently and can be considered the most common culturable species in naturally fermented milk products. Traditional fermented Mongolian cow milk featured a wide diversity of yeast species, including Issatchenkia orientalis, Kazachstania unisporus, Rhodotorula mucilaginosa, Candida pararugosa, Torulaspora delbrueckii, Geotrichum sp., Kazachstania unisporus, Geotrichum fragrans, Debaryomyces hansenii, Yarrowia lipolytica, Trichosporon gracile, and Pichia membranifaciens. This study provides new data on yeast composition in naturally fermented milk and shows the yeast biodiversity of fermented milk products from the Tibetan Plateau of China. PMID:20921981

  15. Diddensiella caesifluorescens gen. nov., sp. nov., a riboflavin-producing yeast species of the family Trichomonascaceae

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Four strains of a novel heterothallic yeast species were isolated from rotten wood collected in or near the Pilis Mountains in Hungary. The strains produced riboflavin in liquid culture. Analysis of gene sequences for the D1/D2 domains of the large subunit nuclear ribosomal RNA (rRNA), as well as an...

  16. Ogataea saltuana sp. nov., a novel methanol-assimilating yeast species

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Four ascosporulating strains of an undescribed methanol-assimilating yeast species were isolated from forest habitats in Hungary. Three of them were recovered from rotten wood and one from leaves of a sessile oak. A closely related, but somewhat divergent strain was recovered from insect frass in a ...

  17. Gene sequence analyses and other DNA-based methods for yeast species recognition

    Technology Transfer Automated Retrieval System (TEKTRAN)

    DNA sequence analyses, as well as other DNA-based methodologies, have transformed the way in which yeasts are identified. The focus of this chapter will be on the resolution of species using various types of DNA comparisons. In other chapters in this book, Rozpedowska, Piškur and Wolfe discuss mul...

  18. Differences in environmental stress response among yeasts is consistent with species-specific lifestyles

    PubMed Central

    Brion, Christian; Pflieger, David; Souali-Crespo, Sirine; Friedrich, Anne; Schacherer, Joseph

    2016-01-01

    Defining how organisms respond to environmental change has always been an important step toward understanding their adaptive capacity and physiology. Variation in transcription during stress has been widely described in model species, especially in the yeast Saccharomyces cerevisiae, which helped to shape general rules regarding how cells cope with environmental constraints, as well as to decipher the functions of many genes. Comparison of the environmental stress response (ESR) across species is essential to obtaining better insight into the common and species-specific features of stress defense. In this context, we explored the transcriptional landscape of the yeast Lachancea kluyveri (formerly Saccharomyces kluyveri) in response to diverse stresses, using RNA sequencing. We investigated variation in gene expression and observed a link between genetic plasticity and environmental sensitivity. We identified the ESR genes in this species and compared them to those already found in S. cerevisiae. We observed common features between the two species, as well as divergence in the regulatory networks involved. Of interest, some changes were related to differences in species lifestyle. Thus we were able to decipher how adaptation to stress has evolved among different yeast species. Finally, by analyzing patterns of coexpression, we were able to propose potential biological functions for 42% of genes and also annotate 301 genes for which no function could be assigned by homology. This large data set allowed for the characterization of the evolution of gene regulation and provides an efficient tool for assessing gene function. PMID:27009200

  19. Delimitation of Neonectria and Cylindrocarpon (Nectriaceae, Hypocreales, Ascomycota) and related genera with Cylindrocarpon-like anamorphs

    PubMed Central

    Chaverri, P.; Salgado, C.; Hirooka, Y.; Rossman, A.Y.; Samuels, G.J.

    2011-01-01

    Neonectria is a cosmopolitan genus and it is, in part, defined by its link to the anamorph genus Cylindrocarpon. Neonectria has been divided into informal groups on the basis of combined morphology of anamorph and teleomorph. Previously, Cylindrocarpon was divided into four groups defined by presence or absence of microconidia and chlamydospores. Molecular phylogenetic analyses have indicated that Neonectria sensu stricto and Cylindrocarpon sensu stricto are phylogenetically congeneric. In addition, morphological and molecular data accumulated over several years have indicated that Neonectria sensu lato and Cylindrocarpon sensu lato do not form a monophyletic group and that the respective informal groups may represent distinct genera. In the present work, a multilocus analysis (act, ITS, LSU, rpb1, tef1, tub) was applied to representatives of the informal groups to determine their level of phylogenetic support as a first step towards taxonomic revision of Neonectria sensu lato. Results show five distinct highly supported clades that correspond to some extent with the informal Neonectria and Cylindrocarpon groups that are here recognised as genera: (1) N. coccinea-group and Cylindrocarpon groups 1 & 4 (Neonectria/Cylindrocarpon sensu stricto); (2) N. rugulosa-group (Rugonectria gen. nov.); (3) N. mammoidea/N. veuillotiana-groups and Cylindrocarpon group 2 (Thelonectria gen. nov.); (4) N. radicicola-group and Cylindrocarpon group 3 (Ilyonectria gen. nov.); and (5) anamorph genus Campylocarpon. Characteristics of the anamorphs and teleomorphs correlate with the five genera, three of which are newly described. New combinations are made for species where their classification is confirmed by phylogenetic data. PMID:21523189

  20. A monograph of Allantonectria, Nectria, and Pleonectria (Nectriaceae, Hypocreales, Ascomycota) and their pycnidial, sporodochial, and synnematous anamorphs

    PubMed Central

    Hirooka, Y.; Rossman, A.Y.; Samuels, G.J.; Lechat, C.; Chaverri, P.

    2012-01-01

    Although Nectria is the type genus of Nectriaceae (Hypocreales, Sordariomycetes, Pezizomycotina, Ascomycota), the systematics of the teleomorphic and anamorphic state of Nectria sensu Rossman has not been studied in detail. The objectives of this study are to 1) provide a phylogenetic overview to determine if species of Nectria with Gyrostroma, Tubercularia, and Zythiostroma anamorphs form a monophyletic group; 2) define Nectria, segregate genera, and their species using morphologically informative characters of teleomorphic and anamorphic states; and 3) provide descriptions and illustrations of these genera and species. To accomplish these objectives, results of phylogenetic analyses of DNA sequence data from six loci (act, ITS, LSU, rpb1, tef1 and tub), were integrated with morphological characterisations of anamorphs and teleomorphs. Results from the phylogenetic analyses demonstrate that species previously regarded as the genus Nectria having Gyrostroma, Tubercularia, and Zythiostroma anamorphs belong in two major paraphyletic clades. The first major clade regarded as the genus Pleonectria contains 26 species with ascoconidia produced by ascospores in asci, perithecial walls having bright yellow scurf, and immersed or superficial pycnidial anamorphs (Zythiostroma = Gyrostroma). A lineage basal to the Pleonectria clade includes Nectria miltina having very small, aseptate ascospores, and trichoderma-like conidiophores and occurring on monocotyledonous plants. These characteristics are unusual in Pleonectria, thus we recognise the monotypic genus Allantonectria with Allantonectria miltina. The second major clade comprises the genus Nectria sensu stricto including the type species, N. cinnabarina, and 28 additional species. Within the genus Nectria, four subclades exist. One subclade includes species with sporodochial anamorphs and another with synnematous anamorphs. The other two paraphyletic subclades include species that produce abundant stromata in which the

  1. Saturnispora quitensis sp. nov., a yeast species isolated from the Maquipucuna cloud forest reserve in Ecuador.

    PubMed

    James, Stephen A; Cadet, Geneviève M; Barriga, Enrique Javier Carvajal; Barahona, Patricia Portero; Cross, Kathryn; Bond, Christopher J; Roberts, Ian N

    2011-12-01

    A single strain, CLQCA-10-114(T), representing a novel yeast species belonging to the genus Saturnispora was isolated from the fruit of an unidentified species of bramble (Rubus sp.), collected from the Maquipucuna cloud forest reserve, near Quito, in Ecuador. Sequence analyses of the D1/D2 domains of the large-subunit rRNA gene and ribosomal internal transcribed spacer region indicated that the novel species is most closely related to the recently described species Saturnispora gosingensis, isolated from the fruiting body of a mushroom collected in Taiwan, and Saturnispora hagleri, a Drosophila-associated yeast found in Brazil. The name Saturnispora quitensis sp. nov. is proposed to accommodate this strain; the type strain is CLQCA-10-114(T) (=CBS 12184(T)=NCYC 3744(T)). PMID:21335499

  2. Evaluation of Different Yeast Species for Improving In vitro Fermentation of Cereal Straws.

    PubMed

    Wang, Zuo; He, Zhixiong; Beauchemin, Karen A; Tang, Shaoxun; Zhou, Chuanshe; Han, Xuefeng; Wang, Min; Kang, Jinhe; Odongo, Nicholas E; Tan, Zhiliang

    2016-02-01

    Information on the effects of different yeast species on ruminal fermentation is limited. This experiment was conducted in a 3×4 factorial arrangement to explore and compare the effects of addition of three different live yeast species (Candida utilis 1314, Saccharomyces cerevisiae 1355, and Candida tropicalis 1254) at four doses (0, 0.25×10(7), 0.50×10(7), and 0.75×10(7) colony-forming unit [cfu]) on in vitro gas production kinetics, fiber degradation, methane production and ruminal fermentation characteristics of maize stover, and rice straw by mixed rumen microorganisms in dairy cows. The maximum gas production (Vf), dry matter disappearance (IVDMD), neutral detergent fiber disappearance (IVNDFD), and methane production in C. utilis group were less (p<0.01) than other two live yeast supplemented groups. The inclusion of S. cerevisiae reduced (p<0.01) the concentrations of ammonia nitrogen (NH3-N), isobutyrate, and isovalerate compared to the other two yeast groups. C. tropicalis addition generally enhanced (p<0.05) IVDMD and IVNDFD. The NH3-N concentration and CH4 production were increased (p<0.05) by the addition of S. cerevisiae and C. tropicalis compared with the control. Supplementation of three yeast species decreased (p<0.05) or numerically decreased the ratio of acetate to propionate. The current results indicate that C. tropicalis is more preferred as yeast culture supplements, and its optimal dose should be 0.25×10(7) cfu/500 mg substrates in vitro. PMID:26732448

  3. The Prevalence and Species Composition of Malassezia yeasts in Patients with Clinically Suspected Onychomycosis

    PubMed Central

    Prohic, Asja; Kuskunovic-Vlahovljak, Suada; Sadikovic, Tamara Jovovic; Cavaljuga, Semra

    2015-01-01

    Introduction: There are limited numbers of studies which focused on the identification of Malassezia yeasts to a species level in onychomycosis. Therefore, the aim of our study was to determine the prevalence and species composition of Malassezia yeasts in patients with clinically suspected onychomycosis and to examine if the range of species varies with patient gender, age, site of involvement and clinical pattern of onychomycosis. Methods: Specimens were taken from 785 patients presenting signs of onychomycosis and then incubated on Sabouraud dextrose agar and modified Dixon agar. The yeasts isolated were identified according to their macroscopic and microscopic features and physiological characteristics. Results: Malassezia species were diagnosed both by microscopy and culture in fourteen (1.8%) patients. M. globosa was the predominant, if not only, species identified from nail samples. Mixed cultures were observed in five cases: in 4 cases Malassezia was co-isolated with Candida albicans and in one case with dermatophyte. Fingernails were affected more frequently than toenails (85.7%) and distolateral subungual onychomycosis was the most common clinical type (78.6%). Conclusion: No significant differences were found in the distribution of Malassezia species isolated according to demographic parameters. PMID:26005253

  4. Identification of Malassezia yeast species isolated from patients with pityriasis versicolor.

    PubMed

    Petry, Vanessa; Tanhausen, Fernanda; Weiss, Luciana; Milan, Thais; Mezzari, Adelina; Weber, Magda Blessmann

    2011-01-01

    Pityriasis versicolor (PV) is a disease with worldwide distribution. Twelve different species of Malassezia yeast have been described. The objective of this study was to determine which species of Malassezia are more prevalent in patients with pityriasis versicolor. Samples were collected by scraping the lesions of 87 patients with a clinical suspicion of pityriasis versicolor. The samples were then submitted to fungal microscopy and culture to identify the species. The species found were: Malassezia sympodialis (30%), Malassezia furfur (25.7%), Malassezia globosa (22.7%), Malassezia restricta (12.1%), Malassezia obtusa (7.6%) and Malassezia slooffiae (1.5%). PMID:21987156

  5. Dissection of quantitative traits by bulk segregant mapping in a protoploid yeast species.

    PubMed

    Sigwalt, Anastasie; Caradec, Claudia; Brion, Christian; Hou, Jing; de Montigny, Jacky; Jung, Paul; Fischer, Gilles; Llorente, Bertrand; Friedrich, Anne; Schacherer, Joseph

    2016-08-01

    Since more than a decade ago, Saccharomyces cerevisiae has been used as a model to dissect complex traits, revealing the genetic basis of a large number of traits in fine detail. However, to have a more global view of the genetic architecture of traits across species, the examination of the molecular basis of phenotypes within non-conventional species would undoubtedly be valuable. In this respect, the Saccharomycotina yeasts represent ideal and potential non-model organisms. Here we sought to assess the feasibility of genetic mapping by bulk segregant analysis in the protoploid Lachancea kluyveri (formerly S. kluyveri) yeast species, a distantly related species to S. cerevisiae For this purpose, we designed a fluorescent mating-type marker, compatible with any mating-competent strains representative of this species, to rapidly create a large population of haploid segregants (>10(5) cells). Quantitative trait loci can be mapped by selecting and sequencing an enriched pool of progeny with extreme phenotypic values. As a test bed, we applied this strategy and mapped the causal loci underlying halotolerance phenotypes in L. kluyveri Overall, this study demonstrates that bulk segregant mapping is a powerful way for investigating the genetic basis of natural variations in non-model yeast organisms and more precisely in L. kluyveri. PMID:27371856

  6. Pseudozyma pruni sp. nov., a novel ustilaginomycetous anamorphic fungus from flowers in Taiwan.

    PubMed

    Liou, Guey-Yuh; Wei, Yu-Hui; Lin, Shie-Jea; Wen, Chiou-Yen; Lee, Fwu-Ling

    2009-07-01

    Two ustilaginomycetous anamorphic strains were isolated from flowers in Taiwan. Phylogenetic analysis based on the combined rRNA gene sequence of internal transcribed spacer 1 (ITS1)-5.8S-ITS2 and large-subunit D1/D2 domains indicated that the closest recognized species was Pseudozyma fusiformata. The results of DNA-DNA hybridization and physiological characteristics showed that the two strains represent a novel species within the genus Pseudozyma. The name Pseudozyma pruni sp. nov. is proposed, with FIRDI 005(T) (=BCRC 34227(T) =CBS 10937(T)) as the type strain. PMID:19542121

  7. Identification of Medically Important Yeast Species by Sequence Analysis of the Internal Transcribed Spacer Regions

    PubMed Central

    Leaw, Shiang Ning; Chang, Hsien Chang; Sun, Hsiao Fang; Barton, Richard; Bouchara, Jean-Philippe; Chang, Tsung Chain

    2006-01-01

    Infections caused by yeasts have increased in previous decades due primarily to the increasing population of immunocompromised patients. In addition, infections caused by less common species such as Pichia, Rhodotorula, Trichosporon, and Saccharomyces spp. have been widely reported. This study extensively evaluated the feasibility of sequence analysis of the rRNA gene internal transcribed spacer (ITS) regions for the identification of yeasts of clinical relevance. Both the ITS1 and ITS2 regions of 373 strains (86 species), including 299 reference strains and 74 clinical isolates, were amplified by PCR and sequenced. The sequences were compared to reference data available at the GenBank database by using BLAST (basic local alignment search tool) to determine if species identification was possible by ITS sequencing. Since the GenBank database currently lacks ITS sequence entries for some yeasts, the ITS sequences of type (or reference) strains of 15 species were submitted to GenBank to facilitate identification of these species. Strains producing discrepant identifications between the conventional methods and ITS sequence analysis were further analyzed by sequencing of the D1-D2 domain of the large-subunit rRNA gene for species clarification. The rates of correct identification by ITS1 and ITS2 sequence analysis were 96.8% (361/373) and 99.7% (372/373), respectively. Of the 373 strains tested, only 1 strain (Rhodotorula glutinis BCRC 20576) could not be identified by ITS2 sequence analysis. In conclusion, identification of medically important yeasts by ITS sequencing, especially using the ITS2 region, is reliable and can be used as an accurate alternative to conventional identification methods. PMID:16517841

  8. Redisposition of phoma-like anamorphs in Pleosporales

    PubMed Central

    de Gruyter, J.; Woudenberg, J.H.C.; Aveskamp, M.M.; Verkley, G.J.M.; Groenewald, J.Z.; Crous, P.W.

    2013-01-01

    The anamorphic genus Phoma was subdivided into nine sections based on morphological characters, and included teleomorphs in Didymella, Leptosphaeria, Pleospora and Mycosphaerella, suggesting the polyphyly of the genus. Recent molecular, phylogenetic studies led to the conclusion that Phoma should be restricted to Didymellaceae. The present study focuses on the taxonomy of excluded Phoma species, currently classified in Phoma sections Plenodomus, Heterospora and Pilosa. Species of Leptosphaeria and Phoma section Plenodomus are reclassified in Plenodomus, Subplenodomus gen. nov., Leptosphaeria and Paraleptosphaeria gen. nov., based on the phylogeny determined by analysis of sequence data of the large subunit 28S nrDNA (LSU) and Internal Transcribed Spacer regions 1 & 2 and 5.8S nrDNA (ITS). Phoma heteromorphospora, type species of Phoma section Heterospora, and its allied species Phoma dimorphospora, are transferred to the genus Heterospora stat. nov. The Phoma acuta complex (teleomorph Leptosphaeria doliolum), is revised based on a multilocus sequence analysis of the LSU, ITS, small subunit 18S nrDNA (SSU), β-tubulin (TUB), and chitin synthase 1 (CHS-1) regions. Species of Phoma section Pilosa and allied Ascochyta species were determined to belong to Pleosporaceae based on analysis of actin (ACT) sequence data. Anamorphs that are similar morphologically to Phoma and described in Ascochyta, Asteromella, Coniothyrium, Plectophomella, Pleurophoma and Pyrenochaeta are included in this study. Phoma-like species, which grouped outside the Pleosporineae based on a LSU sequence analysis, are transferred to the genera Aposphaeria, Paraconiothyrium and Westerdykella. The genera Medicopsis gen. nov. and Nigrograna gen. nov. are introduced to accommodate the medically important species formerly known as Pyrenochaeta romeroi and Pyrenochaeta mackinnonii, respectively. Taxonomic novelties: New genera: Medicopsis Gruyter, Verkley & Crous, Nigrograna Gruyter, Verkley & Crous

  9. Performance of CHROMAGAR candida and BIGGY agar for identification of yeast species

    PubMed Central

    Yücesoy, Mine; Marol, Serhat

    2003-01-01

    Background The importance of identifying the pathogenic fungi rapidly has encouraged the development of differential media for the presumptive identification of yeasts. In this study two differential media, CHROMagar Candida and bismuth sulphite glucose glycine yeast agar, were evaluated for the presumptive identification of yeast species. Methods A total number of 270 yeast strains including 169 Candida albicans, 33 C. tropicalis, 24 C. glabrata, 18 C. parapsilosis, 12 C. krusei, 5 Trichosporon spp., 4 C. kefyr, 2 C. lusitaniae, 1 Saccharomyces cerevisiae and 1 Geotrichum candidum were included. The strains were first identified by germ tube test, morphological characteristics on cornmeal tween 80 agar and Vitek 32 and API 20 C AUX systems. In parallel, they were also streaked onto CHROMagar Candida and bismuth sulphite glucose glycine yeast agar plates. The results were read according to the color, morphology of the colonies and the existance of halo around them after 48 hours of incubation at 37°C. Results The sensitivity and specificity values for C. albicans strains were found to be 99.4, 100% for CHROMagar Candida and 87.0, 75.2% for BiGGY agar, respectively. The sensitivity of CHROMagar Candida to identify C. tropicalis, C. glabrata and C. krusei ranged between 90.9 and 100% while the specificity was 100%. The sensitivity rates for BiGGY agar were 66.6 and 100% while the specificity values were found to be 95.4 and 100% for C. tropicalis and C. krusei, respectively. Conclusions It can be concluded that the use of CHROMagar Candida is an easy and reliable method for the presumptive identification of most commonly isolated Candida species especially C. albicans, C. tropicalis and C. krusei. The lower sensitivity and specificity of BiGGY agar to identify commonly isolated Candida species potentially limits the clinical usefulness of this agar. PMID:14613587

  10. Microjet printing of anamorphic microlens arrays

    NASA Astrophysics Data System (ADS)

    Cox, Weldon R.; Chen, Ting; Ussery, Daryl W.; Hayes, Donald J.; Hoenigman, R. F.; MacFarlane, Duncan L.; Rabinovich, Emmanuil M.

    1996-03-01

    The microjet printing method of micro-optical element fabrication is being used to make arrays of high-performance hemi-elliptical and hemi-cylindrical microlenses for potential use in applications such as collimation of edge-emitting diode laser array beams. The printing method enables both the fabrication of very fast (e.g., f/0.75) microlenses and the potential for reducing costs and increasing flexibility in micro-optics manufacture. The process for fabricating anamorphic microlenses, including those of square or rectangular shape, involves the dispensing and placing of precisely sized microdroplets of optical material onto optical substrates, and then controlling their coalescence and solidification. By varying the number, diameter and spacing of adjacent microdroplets of optical materials deposited at elevated temperatures onto heated substrate, both the dimensional aspect ratios and the ratio of `fast'- to-`slow' focal lengths of a printed hemi-elliptical microlens may be varied over a very wide range. Arrays of hemi-elliptical and hemi-cylindrical microlenses on the order of 100 - 300 micrometers in width and 150 micrometers to 20 mm long, with focal length ratios (fast/slow) from 1 (circular) to 0 (cylindrical), have been printed. A model for predicting printed hemi-elliptical microlens focal lengths from printed lenslet geometry is illustrated, along with an interferometric method of detecting lenslet defects and aberrations.

  11. Yeast species associated with orange juice: evaluation of different identification methods.

    PubMed

    Arias, Covadonga R; Burns, Jacqueline K; Friedrich, Lorrie M; Goodrich, Renee M; Parish, Mickey E

    2002-04-01

    Five different methods were used to identify yeast isolates from a variety of citrus juice sources. A total of 99 strains, including reference strains, were identified using a partial sequence of the 26S rRNA gene, restriction pattern analysis of the internal transcribed spacer region (5.8S-ITS), classical methodology, the RapID Yeast Plus system, and API 20C AUX. Twenty-three different species were identified representing 11 different genera. Distribution of the species was considerably different depending on the type of sample. Fourteen different species were identified from pasteurized single-strength orange juice that had been contaminated after pasteurization (PSOJ), while only six species were isolated from fresh-squeezed, unpasteurized orange juice (FSOJ). Among PSOJ isolates, Candida intermedia and Candida parapsilosis were the predominant species. Hanseniaspora occidentalis and Hanseniaspora uvarum represented up to 73% of total FSOJ isolates. Partial sequence of the 26S rRNA gene yielded the best results in terms of correct identification, followed by classical techniques and 5.8S-ITS analysis. The commercial identification kits RapID Yeast Plus system and API 20C AUX were able to correctly identify only 35 and 13% of the isolates, respectively. Six new 5.8S-ITS profiles were described, corresponding to Clavispora lusitaniae, Geotrichum citri-aurantii, H. occidentalis, H. vineae, Pichia fermentans, and Saccharomycopsis crataegensis. With the addition of these new profiles to the existing database, the use of 5.8S-ITS sequence became the best tool for rapid and accurate identification of yeast isolates from orange juice. PMID:11916718

  12. Identification and distribution of a novel Malassezia species yeast on normal equine skin.

    PubMed

    Nell, A; James, S A; Bond, C J; Hunt, B; Herrtage, M E

    2002-03-30

    This study aimed to investigate the distribution of Malassezia species yeasts on the skin of healthy horses. Acetate tape samples were obtained from the lip, axilla, interbulbar region, groin and anus of 12 healthy horses. The samples were stained and examined microscopically and sites harbouring yeast-like organisms were identified. Contact plates were applied to the skin at these sites and cultured at 26 degrees C and 32 degrees C. No growth was obtained on horse blood, Sabouraud's dextrose or modified Dixon's agar. A pure growth of a Malassezia-type organism was obtained on Sabouraud's dextrose agar enriched with oleic acid when it was incubated at 30 degrees C. It was identified by 26S ribosomal DNA D1/D2 sequence analysis as a member of the genus Malassezia, and most closely related to Malassezia sympodialis. However, the level of sequence divergence indicated that it was a novel species. PMID:11999275

  13. Whole-Genome Sequencing and Intraspecific Analysis of the Yeast Species Lachancea quebecensis

    PubMed Central

    Freel, Kelle C.; Friedrich, Anne; Sarilar, Véronique; Devillers, Hugo; Neuvéglise, Cécile; Schacherer, Joseph

    2016-01-01

    The gold standard in yeast population genomics has been the model organism Saccharomyces cerevisiae. However, the exploration of yeast species outside the Saccharomyces genus is essential to broaden the understanding of genome evolution. Here, we report the analyses of whole-genome sequences of nineisolates from the recently described yeast species Lachancea quebecensis. The genome of one isolate was assembled and annotated, and the intraspecific variability within L. quebecensis was surveyed by comparing the sequences from the eight other isolates to this reference sequence. Our study revealed that these strains harbor genomes with an average nucleotide diversity of π = 2 × 10−3 which is slightly lower, although on the same order of magnitude, as that previously determined for S. cerevisiae (π = 4 × 10−3). Our results show that even though these isolates were all obtained from a relatively isolated geographic location, the same ecological source, and represent a smaller sample size than is available for S. cerevisiae, the levels of divergence are similar to those observed in this model species. This divergence is essentially linked to the presence of two distinct clusters delineated according to geographic location. However, even with relatively similar ranges of genome divergence, L. quebecensis has an extremely low global phenotypic variance of 0.062 compared with 0.59 previously determined in S. cerevisiae. PMID:26733577

  14. Yeast species and genetic heterogeneity within Debaryomyces hansenii along the ripening process of traditional ewes' and goats' cheeses.

    PubMed

    Padilla, Beatriz; Manzanares, Paloma; Belloch, Carmela

    2014-04-01

    The yeasts present during the ripening process of ewes' and goats' cheeses produced in a small traditional dairy in Mediterranean Spain were isolated and identified. Five hundred and thirty strains pertaining to eleven yeast species representing eight genera were identified using molecular methods. Debaryomyces hansenii was the yeast species most frequently isolated in all cheeses. Other yeast species commonly found in dairy products were present at the first maturing weeks. Two yeast species Trichosporon coremiiforme and Trichosporon domesticum have been reported in cheeses for the first time, and Meyerozyma guilliermondii has been newly isolated from goats' cheeses. Yeast species composition changed greatly along the process; although, D. hansenii dominated at the end of ripening in all cheeses. Most yeast isolates were able to hydrolyze casein and fatty acid esters. One hundred and eighty seven D. hansenii isolates were genotyped by PCR amplification of M13 satellites and an UPGMA dendrogram was constructed. The majority of isolates were grouped in 5 clusters while 7 profiles were represented by 1-3 isolates. These results demonstrate the genetic heterogeneity present in D. hansenii strains isolated from raw milk cheeses. PMID:24290639

  15. Strain conformation controls the specificity of cross-species prion transmission in the yeast model.

    PubMed

    Grizel, Anastasia V; Rubel, Aleksandr A; Chernoff, Yury O

    2016-07-01

    Transmissible self-assembled fibrous cross-β polymer infectious proteins (prions) cause neurodegenerative diseases in mammals and control non-Mendelian heritable traits in yeast. Cross-species prion transmission is frequently impaired, due to sequence differences in prion-forming proteins. Recent studies of prion species barrier on the model of closely related yeast species show that colocalization of divergent proteins is not sufficient for the cross-species prion transmission, and that an identity of specific amino acid sequences and a type of prion conformational variant (strain) play a major role in the control of transmission specificity. In contrast, chemical compounds primarily influence transmission specificity via favoring certain strain conformations, while the species origin of the host cell has only a relatively minor input. Strain alterations may occur during cross-species prion conversion in some combinations. The model is discussed which suggests that different recipient proteins can acquire different spectra of prion strain conformations, which could be either compatible or incompatible with a particular donor strain. PMID:27565563

  16. Candida materiae sp. nov., a yeast species isolated from rotting wood in the Atlantic Rain Forest.

    PubMed

    Barbosa, Anne C; Cadete, Raquel M; Gomes, Fátima C O; Lachance, Marc-André; Rosa, Carlos A

    2009-08-01

    Three strains of a novel yeast species, Candida materiae sp. nov., were isolated from rotting wood in an Atlantic rain forest site in Brazil. Analysis of the sequences of the D1/D2 domains of the large-subunit rDNA showed that this species belonged to the Spathaspora clade and was related to Candida jeffriesii and Spathaspora passalidarum. Unlike C. jeffriesii and S. passalidarum, C. materiae sp. nov. did not ferment xylose. The type strain of C. materiae sp. nov. is UFMG-07-C15.1BT (=CBS 10975T=CBMAI 956T). PMID:19605715

  17. Yeast biogeography and the effects of species recognition approaches: the case study of widespread basidiomycetous species from birch forests in Russia.

    PubMed

    Yurkov, Andrey; Inácio, João; Chernov, Ivan Yu; Fonseca, Álvaro

    2015-04-01

    Understanding diversity and distribution patterns of fungi, including yeasts, ultimately depends on accuracy of species recognition. However, different approaches to yeast species recognition often result in different entities or operational taxonomic units. We studied the effects of using different yeast species recognition approaches, namely morphological species recognition (MSR) and phylogenetic species recognition (PSR), on the distribution patterns of widespread basidiomycetous yeasts. Hence, we have revised a collection of yeast fungi isolated from spatially remote birch forests in the Moscow Region and Western Siberia with molecular typing and identification tools. PCR fingerprinting and rDNA sequencing analyses of strains of nine species previously identified on the basis of morphological and physiological tests (MSR) yielded 21 phylogenetic species (PSR), including three currently undescribed taxa. The number of distinct phylogenetic species comprised within a single morphospecies ranged from one to seven. A total of ten species were found in both regions, whereas the distribution of 11 yeasts was restricted to a single region only. Both geographical region and type of substrate (plant or soil) influence yeast distribution. Cryptococcus wieringae, C. victoriae, C. magnus, and Leucosporidium scottii were frequently found on plant substrates, whereas C. terricola and C. podzolicus were associated to soil substrates. Occurrence of C. magnus, C. albidus and Sporobolomyces roseus was found to depend on the geographical region. Microsatellite-PCR fingerprinting, MSP-PCR, applied to studying yeast intraspecific variability revealed three different types of distribution: (a) variability that depends on geographical factors (Curvibasidium cygneicollum, C. podzolicus, C. victoriae), (b) genetic identity irrespectively of the region of isolation (Rhodotorula pinicola, C. terricola), and (c) high degree of genetic variability that did not correlate with region of

  18. Differential identification of Candida species and other yeasts by analysis of (/sup 35/S)methionine-labeled polypeptide profiles

    SciTech Connect

    Shen, H.D.; Choo, K.B.; Tsai, W.C.; Jen, T.M.; Yeh, J.Y.; Han, S.H.

    1988-12-01

    This paper describes a scheme for differential identification of Candida species and other yeasts based on autoradiographic analysis of protein profiles of (/sup 35/S)methionine-labeled cellular proteins separated by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. Using ATCC strains as references, protein profile analysis showed that different Candida and other yeast species produced distinctively different patterns. Good agreement in results obtained with this approach and with other conventional systems was observed. Being accurate and reproducible, this approach provides a basis for the development of an alternative method for the identification of yeasts isolated from clinical specimens.

  19. Diddensiella caesifluorescens gen. nov., sp. nov., a riboflavin-producing yeast species of the family Trichomonascaceae.

    PubMed

    Péter, Gábor; Dlauchy, Dénes; Price, Neil P J; Kurtzman, Cletus P

    2012-12-01

    Four strains of a novel heterothallic yeast species were isolated from rotten wood collected in or near the Pilis Mountains in Hungary. The strains produced riboflavin in liquid culture. Analysis of gene sequences for the D1/D2 domains of the LSU nuclear rRNA, as well as analysis of concatenated gene sequences for the D1/D2 nuclear LSU rRNA, mitochondrial SSU rRNA and cytochrome oxidase II placed the novel species in a small clade including only two recognized species, Candida santjacobensis and Candida transvaalensis, in the family Trichomonascaceae. DNA sequence analyses demonstrated that the novel species was distinct from all currently recognized teleomorphic yeast genera. The name Diddensiella caesifluorescens gen nov., sp. nov. is proposed to accommodate the novel genus and species. The new genus proposed here can be recognized only from gene sequence analysis, because the characters of its asexual reproduction and ascospore formation are shared by several members of the genera Trichomonascus, Sugiyamaella and Spencermartinsiella. The type and isotype strains of D. caesifluorescens are NCAIM Y.01949(T) ( = NRRL Y-48781(T) = CBS 12613(T)) and NCAIM Y.01956(I) ( = NRRL Y-48782(I) = CBS 12614(I)), respectively. In view of their close relatedness to D. caesifluorescens, C. santjacobensis and C. transvaalensis are transferred to the genus Diddensiella as new combinations in accordance with changes in the International Code of Nomenclature for algae, fungi and plants. PMID:22843712

  20. Wickerhamiella slavikovae sp. nov. and Wickerhamiella goesii sp. nov., two yeast species isolated from natural substrates.

    PubMed

    Hagler, Allen N; Ribeiro, José R A; Pinotti, T; Brandão, Luciana R; Pimenta, Raphael S; Lins, U; Lee, Ching-Fu; Hsieh, Chin-Wen; Lachance, Marc-André; Rosa, Carlos A

    2013-08-01

    Two novel yeast species were isolated during three independent studies of yeasts associated with natural substrates in Brazil and Taiwan. Analysis of the sequences of the D1/D2 domains of the large subunit rRNA gene showed that these novel species belong to the Wickerhamiella clade. The first was isolated from freshwater and a leaf of sugar cane (Saccharum officinarum) in Brazil and from leaves of Wedelia biflora in Taiwan. Described here as Wickerhamiella slavikovae sp. nov., it differs by 56 nucleotide substitutions and 19 gaps in the D1/D2 region of the large subunit rRNA gene from Candida sorbophila, the least divergent species. The second species, named Wickerhamiella goesii sp. nov., was isolated from leaves and the rhizosphere of sugar cane collected in Rio de Janeiro, Brazil. The species differs by 54 nucleotide substitutions and nine gaps in the D1/D2 domains from Candida drosophilae, its least divergent relative. The type strains are Wickerhamiella slavikovae sp. nov. IMUFRJ 52096(T) (= CBS 12417(T) = DBVPG 8032(T)) and Wickerhamiella goesii sp. nov. IMUFRJ 52102(T) (= CBS 12419(T) = DBVPG 8034(T)). PMID:23710055

  1. Bullera vrieseae sp. nov., a tremellaceous yeast species isolated from bromeliads.

    PubMed

    Landell, Melissa Fontes; Brandão, Luciana R; Safar, Silvana V B; Gomes, Fatima C O; Félix, Ciro R; Santos, Ana Raquel O; Pagani, Danielle M; Ramos, Jesus P; Broetto, Leonardo; Mott, Tamí; Vainstein, Marilene H; Valente, Patricia; Rosa, Carlos A

    2015-08-01

    Two independent surveys of yeasts associated with different bromeliads in different Brazilian regions led to the proposal of a novel yeast species, Bullera vrieseae sp. nov., belonging to the Tremellales clade (Agaricomycotina, Basidiomycota). Analysis of the sequences in the internal transcribed spacer (ITS) region and D1/D2 domain of the LSU rRNA gene suggested affinity to a phylogenetic lineage that includes Bullera miyagiana and Bullera sakaeratica. Six isolates of the novel species were obtained from different bromeliads and regions in Brazil. Sequence analysis of the D1/D2 domains of the large subunit of the rRNA gene showed that the novel species differs from B. miyagiana and B. sakaeratica by 85 and 64 nt substitutions, respectively and by more than 75 nt substitutions in the ITS region. Phenotypically, Bullera vrieseae sp. nov. can be distinguished from both species based on the assimilation of meso-erythritol, which was negative for B. vrieseae sp. nov. but positive for the others, assimilation of d-glucosamine, which was positive for B. vrieseae sp. nov. but negative for B. miyagiana and of l-sorbose, which was negative for B. vrieseae sp. nov. but positive for B. sakaeratica. The novel species Bullera vrieseae sp. nov. is proposed to accommodate these isolates. The type strain of Bullera vrieseae sp. nov. is UFMG-CM-Y379T (BRO443T; ex-type CBS 13870T). PMID:25911536

  2. A novel flucytosine-resistant yeast species, Candida pseudoaaseri, causes disease in a cancer patient.

    PubMed

    Pfüller, Roland; Gräser, Yvonne; Erhard, Marcel; Groenewald, Marizeth

    2011-12-01

    Some members of the genus Candida are among the most common human fungal pathogens and cause serious diseases especially in immunocompromised people. A yeast was isolated from a blood culture from an immunocompromised cancer patient who suffered from acute pneumonia. The growth characteristics of the yeast on CHROMagar Candida were similar to those of Candida tropicalis, whereas the API ID 32C system identified the yeast as Candida silvicola. On the basis of the nucleotide divergence in the D1/D2 domain of the 26S nuclear rRNA (nrRNA) gene, as well as the internal transcribed spacer (ITS) domain of the nrRNA gene region, a new species, Candida pseudoaaseri sp. nov. with type strain VK065094 (CBS 11170(T)), which was found to be closely related to Candida aaseri, is proposed. While C. aaseri strains were susceptible to all tested antifungals, the new species is resistant to flucytosine and may also be distinguished from C. aaseri by its ability to assimilate l-rhamnose, whereas its colony morphology on CHROMagar Candida may be helpful for differentiation. PMID:21976765

  3. A Novel Flucytosine-Resistant Yeast Species, Candida pseudoaaseri, Causes Disease in a Cancer Patient ▿

    PubMed Central

    Pfüller, Roland; Gräser, Yvonne; Erhard, Marcel; Groenewald, Marizeth

    2011-01-01

    Some members of the genus Candida are among the most common human fungal pathogens and cause serious diseases especially in immunocompromised people. A yeast was isolated from a blood culture from an immunocompromised cancer patient who suffered from acute pneumonia. The growth characteristics of the yeast on CHROMagar Candida were similar to those of Candida tropicalis, whereas the API ID 32C system identified the yeast as Candida silvicola. On the basis of the nucleotide divergence in the D1/D2 domain of the 26S nuclear rRNA (nrRNA) gene, as well as the internal transcribed spacer (ITS) domain of the nrRNA gene region, a new species, Candida pseudoaaseri sp. nov. with type strain VK065094 (CBS 11170T), which was found to be closely related to Candida aaseri, is proposed. While C. aaseri strains were susceptible to all tested antifungals, the new species is resistant to flucytosine and may also be distinguished from C. aaseri by its ability to assimilate l-rhamnose, whereas its colony morphology on CHROMagar Candida may be helpful for differentiation. PMID:21976765

  4. Diversity of yeast and mold species from a variety of cheese types.

    PubMed

    Banjara, Nabaraj; Suhr, Mallory J; Hallen-Adams, Heather E

    2015-06-01

    To generate a comprehensive profile of viable fungi (yeasts and molds) on cheese as it is purchased by consumers, 44 types of cheese were obtained from a local grocery store from 1 to 4 times each (depending on availability) and sampled. Pure cultures were obtained and identified by DNA sequence of the ITS region, as well as growth characteristics and colony morphology. The yeast Debaryomyces hansenii was the most abundant fungus, present in 79 % of all cheeses and 63 % of all samples. Penicillium roqueforti was the most common mold, isolated from a variety of cheeses in addition to the blue cheeses. Eighteen other fungal species were isolated, ten from only one sample each. Most fungi isolated have been documented from dairy products; a few raise potential food safety concerns (i.e. Aspergillus flavus, isolated from a single sample and capable of producing aflatoxins; and Candida parapsilosis, an emerging human pathogen isolated from three cheeses). With the exception of D. hansenii (present in most cheese) and P. roqueforti (a necessary component of blue cheese), no strong correlation was observed between cheese type, manufacturer, or sampling time with the yeast or mold species composition. PMID:25694357

  5. Distinct Signaling Roles of Ceramide Species in Yeast Revealed Through Systematic Perturbation and Systems Biology Analyses

    PubMed Central

    Montefusco, David J.; Chen, Lujia; Matmati, Nabil; Lu, Songjian; Newcomb, Benjamin; Cooper, Gregory F.; Hannun, Yusuf A.; Lu, Xinghua

    2014-01-01

    Ceramide, the central molecule of sphingolipid metabolism, is an important bioactive molecule participating in cellular regulatory events and having implications for disease. A challenge in deciphering ceramide signaling emanates from the myriad of ceramide species that exist and the possibility that many of them may have distinct functions. Here, we applied systems biology and molecular approaches to perturb ceramide metabolism in the yeast (Saccharomyces cerevisiae) and inferred causal relationships between ceramide species and their potential targets by combining lipidomic, genomic, and transcriptomic analyses. We find that during heat stress distinct metabolic mechanisms control the abundance of different groups of ceramide species. Additionally, distinct groups of ceramide species regulated different sets of functionally related genes, indicating that specific sub-groups of lipids participated in different regulatory pathways. These results indicate a previously unrecognized complexity and versatility of lipid-mediated cell regulation. PMID:24170935

  6. Large-Scale Survey of Intraspecific Fitness and Cell Morphology Variation in a Protoploid Yeast Species

    PubMed Central

    Jung, Paul P.; Sigwalt, Anastasie; Ohnuki, Shinsuke; de Montigny, Jacky; Ohya, Yoshikazu; Schacherer, Joseph

    2016-01-01

    It is now clear that the exploration of the genetic and phenotypic diversity of nonmodel species greatly improves our knowledge in biology. In this context, we recently launched a population genomic analysis of the protoploid yeast Lachancea kluyveri (formerly Saccharomyces kluyveri), highlighting a broad genetic diversity (π = 17 × 10−3) compared to the yeast model organism, S. cerevisiae (π = 4 × 10−3). Here, we sought to generate a comprehensive view of the phenotypic diversity in this species. In total, 27 natural L. kluyveri isolates were subjected to trait profiling using the following independent approaches: (i) analyzing growth in 55 growth conditions and (ii) investigating 501 morphological changes at the cellular level. Despite higher genetic diversity, the fitness variance observed in L. kluyveri is lower than that in S. cerevisiae. However, morphological features show an opposite trend. In addition, there is no correlation between the origins (ecological or geographical) of the isolate and the phenotypic patterns, demonstrating that trait variation follows neither population history nor source environment in L. kluyveri. Finally, pairwise comparisons between growth rate correlation and genetic diversity show a clear decrease in phenotypic variability linked to genome variation increase, whereas no such a trend was identified for morphological changes. Overall, this study reveals for the first time the phenotypic diversity of a distantly related species to S. cerevisiae. Given its genetic properties, L. kluyveri might be useful in further linkage mapping analyses of complex traits, and could ultimately provide a better insight into the evolution of the genotype–phenotype relationship across yeast species. PMID:26888866

  7. Population genomic analysis reveals highly conserved mitochondrial genomes in the yeast species Lachancea thermotolerans.

    PubMed

    Freel, Kelle C; Friedrich, Anne; Hou, Jing; Schacherer, Joseph

    2014-10-01

    The increasing availability of mitochondrial (mt) sequence data from various yeasts provides a tool to study genomic evolution within and between different species. While the genomes from a range of lineages are available, there is a lack of information concerning intraspecific mtDNA diversity. Here, we analyzed the mt genomes of 50 strains from Lachancea thermotolerans, a protoploid yeast species that has been isolated from several locations (Europe, Asia, Australia, South Africa, and North / South America) and ecological sources (fruit, tree exudate, plant material, and grape and agave fermentations). Protein-coding genes from the mtDNA were used to construct a phylogeny, which reflected a similar, yet less resolved topology than the phylogenetic tree of 50 nuclear genes. In comparison to its sister species Lachancea kluyveri, L. thermotolerans has a smaller mt genome. This is due to shorter intergenic regions and fewer introns, of which the latter are only found in COX1. We revealed that L. kluyveri and L. thermotolerans share similar levels of intraspecific divergence concerning the nuclear genomes. However, L. thermotolerans has a more highly conserved mt genome with the coding regions characterized by low rates of nonsynonymous substitution. Thus, in the mt genomes of L. thermotolerans, stronger purifying selection and lower mutation rates potentially shape genome diversity in contract to what was found for L. kluyveri, demonstrating that the factors driving mt genome evolution are different even between closely related species. PMID:25212859

  8. Cyberlindnera xylosilytica sp. nov., a xylitol-producing yeast species isolated from lignocellulosic materials.

    PubMed

    Cadete, Raquel M; Cheab, Monaliza A M; Santos, Renata O; Safar, Silvana V B; Zilli, Jerri E; Vital, Marcos J S; Basso, Luiz C; Lee, Ching-Fu; Kurtzman, Cletus P; Lachance, Marc-André; Rosa, Carlos A

    2015-09-01

    Independent surveys of yeasts associated with lignocellulosic-related materials led to the discovery of a novel yeast species belonging to the Cyberlindnera clade (Saccharomycotina, Ascomycota). Analysis of the sequences of the internal transcribed spacer (ITS) region and the D1/D2 domains of the large subunit rRNA gene showed that this species is related to C. japonica, C. maesa and C. easanensis. Six isolates were obtained from different sources, including rotting wood, tree bark and sugar cane filter cake in Brazil, frass from white oak in the USA and decayed leaf in Taiwan. A novel species is suggested to accommodate these isolates, for which the name C. xylosilytica sp. nov. is proposed. The type strain of C. xylosilytica sp. nov. is NRRL YB-2097(T) ( = CBS 13984(T) = UFMG-CM-Y347(T)) and the allotype is UFMG-CM-Y409 ( = CBS 14083). The novel species is heterothallic and complementary mating types are represented by the type and allotype strains. The MycoBank number is MB 811428. PMID:26025941

  9. Species Accumulation Curves and Incidence-Based Species Richness Estimators to Appraise the Diversity of Cultivable Yeasts from Beech Forest Soils

    PubMed Central

    Yurkov, Andrey M.; Kemler, Martin; Begerow, Dominik

    2011-01-01

    Background Yeast-like fungi inhabit soils throughout all climatic zones in a great abundance. While recent estimations predicted a plethora of prokaryotic taxa in one gram of soil, similar data are lacking for fungi, especially yeasts. Methodology/Principal Findings We assessed the diversity of soil yeasts in different forests of central Germany using cultivation-based techniques with subsequent identification based on rDNA sequence data. Based on experiments using various pre-cultivation sample treatment and different cultivation media we obtained the highest number of yeasts by analysing mixed soil samples with a single nutrient-rich medium. Additionally, several species richness estimators were applied to incidence-based data of 165 samples. All of them predicted a similar range of yeast diversity, namely 14 to 16 species. Randomized species richness curves reached saturation in all applied estimators, thus indicating that the majority of species is detected after approximately 30 to 50 samples analysed. Conclusions/Significance In this study we demonstrate that robust species identification as well as mathematical approaches are essential to reliably estimate the sampling effort needed to describe soil yeast communities. This approach has great potential for optimisation of cultivation techniques and allows high throughput analysis in the future. PMID:21858201

  10. Torulaspora indica a novel yeast species isolated from coal mine soils.

    PubMed

    Saluja, Puja; Yelchuri, R K; Sohal, Satinder K; Bhagat, Geetika; Paramjit; Prasad, G S

    2012-05-01

    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. PMID:22200779

  11. Nakazawaea siamensis f.a., sp. nov., a yeast species isolated from phylloplane.

    PubMed

    Kaewwichian, Rungluk; Limtong, Savitree

    2014-01-01

    Strain DMKU-RK467(T), representing a novel yeast species, was isolated from the external surface of sugar cane leaves collected in Thailand. On the basis of morphological, biochemical, physiological and chemotaxonomic characteristics, and sequence analysis of the D1/D2 region of the LSU rRNA gene and the internal transcribed spacer (ITS) region, strain DMKU-RK467(T) was assigned to a novel species of the genus Nakazawaea. The novel species was related most closely to the type strain of Candida wickerhamii but they differed by 1.9 % nucleotide substitutions in the D1/D2 region of the LSU rRNA gene and by 5.2 % nucleotide substitutions in the ITS region. The name Nakazawaea siamensis f.a., sp. nov. is proposed (type strain DMKU-RK467(T) = BCC 50734(T) = NBRC 108903(T) = CBS 12569(T)). PMID:24052626

  12. Wickerhamomyces siamensis sp. nov., a novel yeast species isolated from the phylloplane in Thailand.

    PubMed

    Kaewwichian, Rungluk; Kawasaki, Hiroko; Limtong, Savitree

    2013-04-01

    Strain DMKU-RK359(T), representing a novel yeast species, was isolated from the external surface of a sugar-cane leaf collected in Thailand. On the basis of morphological, biochemical, physiological and chemotaxonomic characteristics, sequence analysis of the D1/D2 region of the large-subunit (LSU) rRNA gene and the internal transcribed spacer (ITS) region, strain DMKU-RK359(T) was assigned to a novel Wickerhamomyces species. The novel species was closest to Wickerhamomyces ciferrii, but differed from it by 0.7 % nucleotide substitutions in the D1/D2 region of the LSU rRNA gene and 6 % nucleotide substitutions in the ITS region. The name Wickerhamomyces siamensis sp. nov. is proposed (type strain DMKU-RK359(T)  = BCC 50732(T)  = NBRC 108900(T)  = CBS 12570(T)). PMID:23396723

  13. Phylogenetic placement of the lichenicolous, anamorphic genus Lichenodiplis and its connection to Muellerella-like teleomorphs.

    PubMed

    Muggia, Lucia; Kopun, Theodora; Ertz, Damien

    2015-11-01

    Lichenicolous fungi are a specialized group of taxa which inhabit lichens and develop diverse degrees of specificity and parasitic behaviour towards their hosts. They are recognized only by their phenotypic symptoms and sexual or asexual spore-producing structures on the lichen thalli. Only recently, molecular data and culture dependent approaches have helped in uncovering the species diversity and in verifying the phylogenetic position and anamorph-teleomorph relationships of some taxa. Here, we studied the phylogenetic placement of representative taxa of two lichenicolous genera, the coelomycete Lichenodiplis and the ascomycete Muellerella. We obtained molecular data for three nuclear and mitochondrial loci (28S, 18S, and 16S), both from fresh collected specimens and culture isolates. Our multilocus phylogeny places Lichenodiplis and Muellerella samples in one monophyletic, fully supported clade, sister to Epibryon (Epibryaceae) in Chaetothyriales (Eurotiomycetes). Morphological analyses of axenically cultured fungi show the formation of conidiomata and conidiospores in both Lichenodiplis and Muellerella isolates. We suggest that the species Lichenodiplis lecanorae and Muellerella atricola represent, respectively, the anamorphic and teleomorphic stages of the same fungus and discuss their relationships with the other fungal families in Chaetothyriomycetidae. PMID:26466884

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

    PubMed

    Landell, Melissa Fontes; Brandão, Luciana R; Barbosa, Anne C; Ramos, Jesus P; Safar, Silvana V B; Gomes, Fatima C O; Sousa, Francisca M P; Morais, Paula B; Broetto, Leonardo; Leoncini, Orílio; Ribeiro, José Roberto; Fungsin, Bundit; Takashima, Masako; Nakase, Takashi; Lee, Ching-Fu; Vainstein, Marilene H; Fell, Jack W; Scorzetti, Gloria; Vishniac, Helen S; Rosa, Carlos A; Valente, Patricia

    2014-06-01

    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)). PMID:24614844

  15. Phylogenetic reassessment of Mycosphaerella spp. and their anamorphs occurring on Eucalyptus. II.

    PubMed Central

    Crous, Pedro W.; Wingfield, Michael J.; Mansilla, J. Pedro; Alfenas, Acelino C.; Groenewald, Johannes Z.

    2006-01-01

    Species of Eucalyptus are widely planted as exotics in the tropics and Southern Hemisphere and to some extent in southern Europe, for timber and fibre production. Species of Mycosphaerella are commonly associated with leaves and twigs of Eucalyptus and can result in defoliation, dieback, and even tree death. In the present study, numerous isolates of Mycosphaerella species were collected from leaf litter, living leaves exhibiting leaf spot symptoms or severe Mycosphaerella leaf blotch symptoms. Isolates were compared based on DNA sequence data for the internal transcribed spacer region (ITS1 & ITS2) and the 5.8S gene. These data, together with characteristics of the fungal growth on three different media, morphology of the anamorph and teleomorph structures as well as ascospore germination patterns were used to describe 21 new species. PMID:18490974

  16. Evaluation of Automated Yeast Identification System

    NASA Technical Reports Server (NTRS)

    McGinnis, M. R.

    1996-01-01

    One hundred and nine teleomorphic and anamorphic yeast isolates representing approximately 30 taxa were used to evaluate the accuracy of the Biolog yeast identification system. Isolates derived from nomenclatural types, environmental, and clinica isolates of known identity were tested in the Biolog system. Of the isolates tested, 81 were in the Biolog database. The system correctly identified 40, incorrectly identified 29, and was unable to identify 12. Of the 28 isolates not in the database, 18 were given names, whereas 10 were not. The Biolog yeast identification system is inadequate for the identification of yeasts originating from the environment during space program activities.

  17. Ogataea saltuana sp. nov., a novel methanol-assimilating yeast species.

    PubMed

    Péter, Gábor; Dlauchy, Dénes; Tornai-Lehoczki, Judit; Gouliamova, Dilnora; Kurtzman, Cletus P

    2011-10-01

    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. PMID:21618050

  18. Issatchenkia hanoiensis, a new yeast species isolated from frass of the litchi fruit borer Conopomorpha cramerella Snellen.

    PubMed

    Vu, Nguyen Vu; Dao, Anh Hai; Lachance, Marc-André

    2003-10-01

    The new ascogenous yeast species Issatchenkia hanoiensis was discovered in the frass of the litchi fruit borer Conopomorpha cramerella Snellen. The yeast forms unconjugated persistent asci containing one to two roughened ascospores. The yeast has a CoQ-7 system, which is typical for the genus Issatchenkia. The closest species to I. hanoiensis as indicated by analysis of the partial ribosomal DNA large-subunit (D1/D2) sequence is the asexual species Candida pseudolambica. The two share 94.2% similarity in the sequenced region. Other species of Issatchenkia were also among the closest relatives of I. hanoiensis, the level of similarity ranging from 89.8% to 94.1%. The type culture is strain HB1.3.13=CBS 9198=NRRL Y-27509. PMID:14554203

  19. Honey Bees Avoid Nectar Colonized by Three Bacterial Species, But Not by a Yeast Species, Isolated from the Bee Gut

    PubMed Central

    Good, Ashley P.; Gauthier, Marie-Pierre L.; Vannette, Rachel L.; Fukami, Tadashi

    2014-01-01

    The gut microflora of the honey bee, Apis mellifera, is receiving increasing attention as a potential determinant of the bees’ health and their efficacy as pollinators. Studies have focused primarily on the microbial taxa that appear numerically dominant in the bee gut, with the assumption that the dominant status suggests their potential importance to the bees’ health. However, numerically minor taxa might also influence the bees’ efficacy as pollinators, particularly if they are not only present in the gut, but also capable of growing in floral nectar and altering its chemical properties. Nonetheless, it is not well understood whether honey bees have any feeding preference for or against nectar colonized by specific microbial species. To test whether bees exhibit a preference, we conducted a series of field experiments at an apiary using synthetic nectar inoculated with specific species of bacteria or yeast that had been isolated from the bee gut, but are considered minor components of the gut microflora. These species had also been found in floral nectar. Our results indicated that honey bees avoided nectar colonized by the bacteria Asaia astilbes, Erwinia tasmaniensis, and Lactobacillus kunkeei, whereas the yeast Metschnikowia reukaufii did not affect the feeding preference of the insects. Our results also indicated that avoidance of bacteria-colonized nectar was caused not by the presence of the bacteria per se, but by the chemical changes to nectar made by the bacteria. These findings suggest that gut microbes may not only affect the bees’ health as symbionts, but that some of the microbes may possibly affect the efficacy of A. mellifera as pollinators by altering nectar chemistry and influencing their foraging behavior. PMID:24466119

  20. Preparation of species-specific murine monoclonal antibodies against the yeast phase of Paracoccidioides brasiliensis.

    PubMed Central

    Figueroa, J I; Hamilton, A J; Bartholomew, M A; Harada, T; Fenelon, L; Hay, R J

    1990-01-01

    A panel of four murine monoclonal antibodies showing species specificity for the yeast phase of the pathogenic dimorphic fungus Paracoccidioides brasiliensis was produced by using a modification of the standard monoclonal antibody technology. This involved the use of the immunosuppressive drug cyclophosphamide to suppress the immune response of test animals to fungi showing cross-reactivity, i.e., to Histoplasma capsulatum. One monoclonal antibody, P4, which had a high titer by enzyme-linked immunosorbent assay, was shown to recognize a linear antigenic epitope of P. brasiliensis at a molecular size of 70,000 to 75,000 daltons by Western blot (immunoblot) analysis. The potential use of these monoclonal antibodies, which are the first species-specific probes to P. brasiliensis that have been produced, in the field of serodiagnosis is discussed. Images PMID:2394802

  1. The anamorphic genus Monotosporella (Ascomycota) from Eocene amber and from modern Agathis resin.

    PubMed

    Sadowski, Eva-Maria; Beimforde, Christina; Gube, Matthias; Rikkinen, Jouko; Singh, Hukam; Seyfullah, Leyla J; Heinrichs, Jochen; Nascimbene, Paul C; Reitner, Joachim; Schmidt, Alexander R

    2012-10-01

    The anamorphic fungal genus Monotosporella (Ascomycota, Sordariomycetes) has been reco-vered from a piece of Early Eocene Indian amber, as well as from the surface of extant resin flows in New Caledonia. The fossil fungus was obtained from the Tarkeshwar Lignite Mine of Gujarat State, western India, and was part of the biota of an early tropical angiosperm rainforest. The amber inclusion represents the second fossil record of Sordariomycetes, as well as the first fossil of its particular order (either Savoryellales or Chaetosphaeriales). The fossil fungus is distinguished from extant representatives by possessing both short conidiophores and small two-septate pyriform conidia, and is described as Monotosporella doerfeltii sp. nov. Inside the amber, the anamorph is attached to its substrate, which is likely the degraded thallus of a cladoniform lichen. The extant New Caledonian species is assigned to Monotosporella setosa. It was found growing on semi-solidified resin flows of Agathis ovata (Araucariaceae), and is the first record of Monotosporella from modern resin substrates. PMID:23063189

  2. Manipulation of culture conditions alters lipid content and fatty acid profiles of a wide variety of known and new oleaginous yeasts species

    PubMed Central

    Sitepu, Irnayuli R.; Sestric, Ryan; Ignatia, Laura; Levin, David; German, J. Bruce; Gillies, Laura A.; Almada, Luis A.G.; Boundy-Mills, Kyria L.

    2013-01-01

    Oleaginous yeasts have been studied for oleochemical production for over 80 years. Only a few species have been studied intensely. To expand the diversity of oleaginous yeasts available for lipid research, we surveyed a broad diversity of yeasts with indicators of oleaginicity including known oleaginous clades, and buoyancy. Sixty-nine strains representing 17 genera and 50 species were screened for lipid production. Yeasts belonged to Ascomycota families, Basidiomycota orders, and the yeast-like algal genus Prototheca. Total intracellular lipids and fatty acid composition were determined under different incubation times and nitrogen availability. Thirteen new oleaginous yeast species were discovered, representing multiple ascomycete and basidiomycete clades. Nitrogen starvation generally increased intracellular lipid content. The fatty acid profiles varied with the growth conditions regardless of taxonomic affiliation. The dominant fatty acids were oleic acid, palmitic acid, linoleic acid, and stearic acid. Yeasts and culture conditions that produced fatty acids appropriate for biodiesel were identified. PMID:23891835

  3. Osmotolerant yeast species differ in basic physiological parameters and in tolerance of non-osmotic stresses.

    PubMed

    Bubnová, Michala; Zemančíková, Jana; Sychrová, Hana

    2014-08-01

    Osmotolerance is the ability to grow in an environment with a high osmotic pressure. In this study we compared the physiological parameters and tolerance to osmotic and non-osmotic stresses of three osmotolerant yeast species, Debaryomyces hansenii, Pichia farinosa (sorbitophila) and Zygosaccharomyces rouxii, with those of wild-type Saccharomyces cerevisiae. Although the osmotolerant species did not differ significantly in their basic parameters, such as cell size or growth capacity, they had different abilities to survive anhydrobiosis, potassium limitation or the presence of toxic cationic drugs. When their osmotolerance was compared, the results revealed that some of the species isolated as sugar/polyol-tolerant (e.g.  P. farinosa) are also highly tolerant to salts and, vice versa, some strains isolated from an environment with high concentration of salt (e.g. Z. rouxii ATCC 42981) tolerate high concentrations of sugars. None of the tested strains and species was osmophilic. Taken together, our results showed that P. farinosa (sorbitophila) is the most robust species when coping with various stresses, while Z. rouxii CBS 732, although osmotolerant in general, is not specifically salt-tolerant and is quite sensitive to most of the tested stress conditions. PMID:24962688

  4. Existence and expression of photoreactivation repair genes in various yeast species.

    PubMed

    Yasui, A; Eker, A P; Koken, M

    1989-01-01

    Photoreactivation repair (Phr) activities in cell extracts of 13 different yeast species were measured by the Haemophilus influenzae transformation assay. Five species including Schizosaccharomyces pombe showed no or low enzymatic activity. In contrast to the other species, chromosomal DNAs of these 5 species did not show detectable hybridization using a DNA fragment of the photolyase PHR1 gene of Saccharomyces cervisiae as a probe even at a low stringency condition. When the PHR1 gene was attached to the 5'-flanking sequence of the iso-1-cytochrome c (CYC-1) gene of S. cerevisiae and introduced into S. pombe cells, the transformants acquired a high Phr activity, indicating that the PHR1 gene alone can provide a Phr-negative species with this repair activity and the light-absorbing cofactor(s) must be present in S. pombe. Our results also demonstrated that the 5'-flanking sequence of the S. cerevisiae CYC-1 gene works in S. pombe as a regulatory element. PMID:2911265

  5. Candida species and other yeasts in the oral cavities of type 2 diabetic patients in Cali, Colombia

    PubMed Central

    Álvarez, María Inés; de Bernal, Matilde; Collazos, Andrés

    2013-01-01

    Objective: To determine the prevalence of Candida species and to study factors associated to oral cavity colonization in patients with type 2 diabetes mellitus. Methods: A total of 107 diabetics were classified into controlled and uncontrolled according to glycosylated hemoglobin values. Each patient was assessed for stimulated salivary flow rates, pH, and an oral rinse to search for yeast. The study also determined the state of oral health via Klein and Palmer CPO indexes for permanent dentition, dental plaque by O'Leary, and a periodontal chart. Results: We found yeasts in 74.8% of the patients. A total of 36 of the 52 subjects with controlled diabetes presented yeasts and 44 in the uncontrolled; no significant differences (p = 0.2) were noted among the presence of yeasts and the control of blood glucose. The largest number of isolates corresponded to C. albicans, followed by C. parapsilosis. Uncontrolled individuals presented a significantly higher percentage of yeast different from C. albicans (p = 0.049). Conclusions: We found a high percentage of Candida colonization and uncontrolled individuals had greater diversity of species. The wide range of CFU/mL found both in patients with oral candidiasis, as well as in those without it did not permit distinguishing between colonization and disease. We only found association between isolation of yeasts and the low rate of salivary flow. PMID:24892318

  6. Taxonomy and physiological characterisation of Scheffersomyces titanus sp. nov., a new D-xylose-fermenting yeast species from China

    PubMed Central

    Liu, Xiao-Jing; Cao, Wan-Nan; Ren, Yong-Cheng; Xu, Long-Long; Yi, Ze-Hao; Liu, Zheng; Hui, Feng-Li

    2016-01-01

    Three strains of a d-xylose-fermenting yeast species were isolated from the host beetle Dorcus titanus collected from two different localities in Henan Province, Central China. These strains formed two hat-shaped ascospores in conjugated and deliquescent asci. Multilocus phylogenetic analysis that included the nearly complete small subunit (SSU), the internal transcribed spacer (ITS) region and the D1/D2 domains of the large subunit (LSU) rDNAs, as well as RNA polymerase II largest subunit (RPB1) gene demonstrated that these strains represent a novel yeast species belonging to the genus Scheffersomyces. The phylogenetic analysis based on the nucleotide sequences of the xylose reductase (XYL1) gene supported the view that the new strains could be grouped as a unique species. Although this new species is highly similar to Scheffersomyces stipitis-like yeasts in terms of nrDNA sequences and morphological and physiological characteristics, the species can be clearly differentiated from its close relatives on the basis of the sequences of XYL1 and RPB1. Therefore, a novel yeast species, Scheffersomyces titanus sp. nov., is proposed to accommodate these strains. The type strain is NYNU 14712T (CICC 33061T = CBS 13926T). PMID:27558134

  7. Taxonomy and physiological characterisation of Scheffersomyces titanus sp. nov., a new D-xylose-fermenting yeast species from China.

    PubMed

    Liu, Xiao-Jing; Cao, Wan-Nan; Ren, Yong-Cheng; Xu, Long-Long; Yi, Ze-Hao; Liu, Zheng; Hui, Feng-Li

    2016-01-01

    Three strains of a d-xylose-fermenting yeast species were isolated from the host beetle Dorcus titanus collected from two different localities in Henan Province, Central China. These strains formed two hat-shaped ascospores in conjugated and deliquescent asci. Multilocus phylogenetic analysis that included the nearly complete small subunit (SSU), the internal transcribed spacer (ITS) region and the D1/D2 domains of the large subunit (LSU) rDNAs, as well as RNA polymerase II largest subunit (RPB1) gene demonstrated that these strains represent a novel yeast species belonging to the genus Scheffersomyces. The phylogenetic analysis based on the nucleotide sequences of the xylose reductase (XYL1) gene supported the view that the new strains could be grouped as a unique species. Although this new species is highly similar to Scheffersomyces stipitis-like yeasts in terms of nrDNA sequences and morphological and physiological characteristics, the species can be clearly differentiated from its close relatives on the basis of the sequences of XYL1 and RPB1. Therefore, a novel yeast species, Scheffersomyces titanus sp. nov., is proposed to accommodate these strains. The type strain is NYNU 14712(T) (CICC 33061(T) = CBS 13926(T)). PMID:27558134

  8. Starmerella orientalis f.a., sp. nov., an ascomycetous yeast species isolated from flowers.

    PubMed

    Alimadadi, Nayyereh; Soudi, Mohammad Reza; Wang, Shi-An; Wang, Qi-Ming; Talebpour, Zahra; Bai, Feng-Yan

    2016-03-01

    Four strains of a novel ascomycetous yeast species were isolated from flowers in Iran and China. Phylogenetic analysis of the sequences of the ITS region (including 5.8S rRNA gene) and the LSU rRNA gene D1/D2 domains indicated that these strains belong to the Starmerella clade and show divergence from previously described species in this clade. Growth reactions on carbon and nitrogen sources were similar to those observed in related species of the Starmerella clade. Sexual reproduction was not observed after mating tests on different sporulation media. Based on physiological characteristics and phylogeny of rRNA gene sequences, the novel species is most closely related to Candida (iter. nom. Starmerella) powellii and Candida (iter. nom. Starmerella) floricola. It is therefore assigned to the genus Starmerella and described as Starmerella orientalis f.a., sp. nov. The type strain is SAM09T ( = IBRC-M 30204T = CBS 14142T). The MycoBank accession number is MB 814379. PMID:26780917

  9. Unraveling the Enzymatic Basis of Wine "Flavorome": A Phylo-Functional Study of Wine Related Yeast Species.

    PubMed

    Belda, Ignacio; Ruiz, Javier; Alastruey-Izquierdo, Ana; Navascués, Eva; Marquina, Domingo; Santos, Antonio

    2016-01-01

    Non-Saccharomyces yeasts are a heterogeneous microbial group involved in the early stages of wine fermentation. The high enzymatic potential of these yeasts makes them a useful tool for increasing the final organoleptic characteristics of wines in spite of their low fermentative power. Their physiology and contribution to wine quality are still poorly understood, with most current knowledge being acquired empirically and in most cases based in single species and strains. This work analyzed the metabolic potential of 770 yeast isolates from different enological origins and representing 15 different species, by studying their production of enzymes of enological interest and linking phylogenetic and enzymatic data. The isolates were screened for glycosidase enzymes related to terpene aroma release, the β-lyase activity responsible for the release of volatile thiols, and sulfite reductase. Apart from these aroma-related activities, protease, polygalacturonase and cellulase activities were also studied in the entire yeast collection, being related to the improvement of different technological and sensorial features of wines. In this context, and in terms of abundance, two different groups were established, with α-L-arabinofuranosidase, polygalacturonase and cellulase being the less abundant activities. By contrast, β-glucosidase and protease activities were widespread in the yeast collection studied. A classical phylogenetic study involving the partial sequencing of 26S rDNA was conducted in conjunction with the enzymatic profiles of the 770 yeast isolates for further typing, complementing the phylogenetic relationships established by using 26S rDNA. This has rendered it possible to foresee the contribution different yeast species make to wine quality and their potential applicability as pure inocula, establishing species-specific behavior. These consistent results allowed us to design future targeted studies on the impact different non-Saccharomyces yeast species

  10. Unraveling the Enzymatic Basis of Wine “Flavorome”: A Phylo-Functional Study of Wine Related Yeast Species

    PubMed Central

    Belda, Ignacio; Ruiz, Javier; Alastruey-Izquierdo, Ana; Navascués, Eva; Marquina, Domingo; Santos, Antonio

    2016-01-01

    Non-Saccharomyces yeasts are a heterogeneous microbial group involved in the early stages of wine fermentation. The high enzymatic potential of these yeasts makes them a useful tool for increasing the final organoleptic characteristics of wines in spite of their low fermentative power. Their physiology and contribution to wine quality are still poorly understood, with most current knowledge being acquired empirically and in most cases based in single species and strains. This work analyzed the metabolic potential of 770 yeast isolates from different enological origins and representing 15 different species, by studying their production of enzymes of enological interest and linking phylogenetic and enzymatic data. The isolates were screened for glycosidase enzymes related to terpene aroma release, the β-lyase activity responsible for the release of volatile thiols, and sulfite reductase. Apart from these aroma-related activities, protease, polygalacturonase and cellulase activities were also studied in the entire yeast collection, being related to the improvement of different technological and sensorial features of wines. In this context, and in terms of abundance, two different groups were established, with α-L-arabinofuranosidase, polygalacturonase and cellulase being the less abundant activities. By contrast, β-glucosidase and protease activities were widespread in the yeast collection studied. A classical phylogenetic study involving the partial sequencing of 26S rDNA was conducted in conjunction with the enzymatic profiles of the 770 yeast isolates for further typing, complementing the phylogenetic relationships established by using 26S rDNA. This has rendered it possible to foresee the contribution different yeast species make to wine quality and their potential applicability as pure inocula, establishing species-specific behavior. These consistent results allowed us to design future targeted studies on the impact different non-Saccharomyces yeast species

  11. Candida queiroziae sp. nov., a cellobiose-fermenting yeast species isolated from rotting wood in Atlantic Rain Forest.

    PubMed

    Santos, Renata O; Cadete, Raquel M; Badotti, Fernanda; Mouro, Adriane; Wallheim, Daniela O; Gomes, Fátima C O; Stambuk, Boris U; Lachance, Marc-André; Rosa, Carlos A

    2011-03-01

    Eight strains of a novel yeast species were isolated from rotting wood and wood-boring insects in Atlantic Rain Forest ecosystems in Brazil. Sequences of the D1/D2 domains of the large subunit of the rRNA gene showed that the yeast belongs to the Scheffersomyces clade and that it is related to Candida lignicola and Candida coipomoensis. The new species was isolated from rotting wood of three different localities and a wood-boring insect suggesting that these substrates are its ecological niche. This new yeast species is able to assimilate cellobiose and other compounds related to rotting wood. Strong fermentation of cellobiose in Durham tubes was observed for the strains of this new yeast. The new species produced an intracellular β-glucosidase responsible for cellobiose hydrolysis. The novel species, Candida queiroziae sp. nov., is proposed to accommodate these isolates. The type strain of C. queiroziae is UFMG-CLM 5.1(T) (=CBS 11853(T) = NRRL Y-48722(T)). PMID:21136162

  12. Candida flosculorum sp. nov. and Candida floris sp. nov., two yeast species associated with tropical flowers.

    PubMed

    Rosa, Carlos A; Pagnocca, Fernando C; Lachance, Marc-André; Ruivo, Carla C C; Medeiros, Adriana O; Pimentel, Mariana R C; Fontenelle, Julio C R; Martins, Rogério P

    2007-12-01

    Two ascomycetous yeast species, Candida flosculorum sp. nov. and Candida floris sp. nov., were isolated from tropical flowers and their associated insects. C. flosculorum was isolated from flower bracts of Heliconia velloziana and Heliconia episcopalis (Heliconiaceae) collected from two Atlantic rain forest sites in Brazil. C. floris was isolated from flowers of Ipomoea sp. (Convolvulaceae) growing on the banks of the river Paraguai in the pantanal ecosystem in Brazil and from an adult of the stingless bee Trigona sp. and a flower of Merremia quinquefolia (Convolvulaceae) in Costa Rica. C. flosculorum belongs to the Metschnikowiaceae clade and C. floris belongs to the Starmerella clade. The type strain of C. flosculorum is UFMG-JL13(T) (=CBS 10566(T)=NRRL Y-48258(T)) and the type strain of C. floris is UWO(PS) 00-226.2(T) (=CBS 10593(T)=NRRL Y-48255(T)). PMID:18048759

  13. Molecular Phylogeny and Taxonomy of Yamadazyma dushanensis f.a., sp. nov., a Cellobiose-Fermenting Yeast Species from China.

    PubMed

    Wang, Yun; Ren, Yong-Cheng; Li, Ying; Hui, Feng-Li

    2015-08-01

    Three yeast strains of Yamadazyma dushanensis f.a., sp. nov. were isolated from rotten wood samples collected in the Dushan Forest Park, Nanyang, Henan Province, China. Sequence analyses of the D1/D2 domains of the large subunit rRNA gene and the internal transcribed spacer (ITS) regions revealed that this new species is located in the Yamadazyma clade (Debaryomycetaceae and Saccharomycetales), with three closely related species, namely, Yamadazyma terventina, Yamadazyma mexicana and Candida trypodendroni. The novel species differed from these three described species by 5-6 nt substitutions in the D1/D2 sequences. However, the ITS sequences of the new species were quite divergent from those of Y. terventina, Y. mexicana and C. trypodendroni with 12-18 nt substitutions. This new yeast species could assimilate cellobiose and other compounds related to rotting wood. The fermentation of cellobiose in Durham tubes was observed for the strains of this new yeast. The new species could also be distinguished from its closely related species, Y. terventina, Y. mexicana and C. trypodendroni, based on a number of morphological and physiological characteristics. The type strain is Y. dushanensis sp. nov. NYNU 14668 (T) (=CICC 33051(T) = CBS 13914(T)). PMID:26037380

  14. Species-wide survey reveals the various flavors of intraspecific reproductive isolation in yeast.

    PubMed

    Hou, Jing; Fournier, Téo; Schacherer, Joseph

    2016-08-01

    Exploring the origin and extent of reproductive isolation within the same species is valuable to capture early events to the onset of speciation. In multiple genetic models, reproductive isolation was recently observed at the intraspecific scale, indicating that the raw potential for speciation segregates readily within populations, which could be a rule rather than an exception in a broad context. We briefly recapitulate the molecular evidence of intrinsic post-zygotic isolation in major model organisms including Arabidopsis thaliana, Caenorhabditis elegans, Drosophila melanogaster and their close relatives. We then focus on recent advances in yeast and review the genetic basis of post-zygotic isolation within and between multiple members of the Saccharomyces genus, especially in Saccharomyces cerevisiae We discuss the role of various mechanisms involved in the onset of reproductive isolation including DNA sequence divergence, chromosomal rearrangement, cytonuclear as well as nuclear-nuclear genetic incompatibilities and provide a comparative view along a continuum of genetic differentiation, which encompasses intraspecific populations, recent delineating nascent species as well as closely related sister species in the same subphylum. PMID:27288348

  15. Candida funiuensi sp. nov., a cellobiose-fermenting yeast species isolated from rotten wood.

    PubMed

    Wang, Yun; Ren, Yong-Cheng; Zhang, Zheng-Tian; Wu, Fu-Hua; Ke, Tao; Hui, Feng-Li

    2015-06-01

    Two strains of an asexual cellobiose-fermenting yeast species were isolated from rotten wood samples collected in Funiu Mountain Nature Reserve in Henan Province, central China. Molecular phylogenetic analysis that included the nearly complete small subunit (SSU), the internal transcribed spacer (ITS) region and the D1/D2 domains of the large subunit (LSU) rDNA showed that these strains belonged to the Candida kruisii clade, with Candida kruisii and Candida cretensis as their closest phylogenetic neighbours. The nucleotide differences between the novel strains and the type strains of C. kruisii and C. cretensis were 30 and 36 substitutions, respectively, in the D1/D2 LSU rDNA, 40 and 44 substitutions, respectively, in the ITS region and 19 and 23 substitutions, respectively, in the SSU rDNA. The novel strains can also be distinguished from their closest described species, C. kruisii and C. cretensis, by a number of physiological characteristics, and represent a novel species of the genus Candida, for which the name Candida funiuensis sp. nov. is proposed. The type strain is NYNU 14625T ( = CICC 33050T = CBS 13911T). The Mycobank number is MB 811503. PMID:25740930

  16. Candida pruni sp. nov. is a new yeast species with antagonistic potential against brown rot of peaches.

    PubMed

    Zhang, Dian-peng; Lu, Cai-ge; Zhang, Tao-tao; Spadaro, Davide; Liu, De-wen; Liu, Wei-cheng

    2014-07-01

    Brown rot caused by Monilinia spp. is among the most important postharvest diseases of commercially grown stone fruits, and application of antagonistic yeasts to control brown rot is one promising strategy alternative to chemical fungicides. In this research, new yeast strains were isolated and tested for their activity against peach brown rot caused by Monilinia fructicola. Three yeast strains were originally isolated from the surface of plums (cv Chinese Angelino) collected in the north of China. In artificially wounded inoculation tests, the yeast reduced the brown rot incidence to 20 %. The population of the yeast within inoculated wounds on peaches significantly increased at 25 °C from an initial level of 5.0×10(6) to 4.45×10(7) CFU per wound after 1 day. The antagonistic strains were belonging to a new species of the genus Candida by sequence comparisons of 26 S rDNA D1/D2 domain and internal transcribed spacer region. The strains are most closely related to C. asparagi, C. musae and C. fructus on the basis of the phylogenetic trees based on the D1/D2 region of 26S rDNA. However, the strains are notably different from C. asparagi, C. musae and C. fructus, in morphological and physiological characteristics. Therefore, the name Candida pruni is proposed for the novel species, with sp-Quan (=CBS12814T=KCTC 27526T=GCMC 6582T) as the type strain. Our study showed that Candida pruni is a novel yeast species with potential biocontrol against brown rot caused by M. fructicola on peaches. PMID:24908073

  17. Pathogenicity and drug resistance in Candida albicans and other yeast species. A review.

    PubMed

    Mishra, Nagendra Nath; Prasad, Tulika; Sharma, Neeraj; Payasi, Anurag; Prasad, Rajendra; Gupta, Dwijendra K; Singh, Randhir

    2007-09-01

    Pathogenic yeasts from the genus Candida can cause serious infection in humans particularly, in immunocompromised patients and are now recognized as major agents of hospital acquired (nosocomial) infections. In the recent years, there has been a marked increase in the incidence of treatment failures in candidiasis patients receiving long-term antifungal therapy, which has posed a serious problem in its successful use in chemotherapy. Candida cells acquire drug resistance (MDR) during the course of the treatment. The mechanisms of resistance to azole antifungal agents have been elucidated in Candida species and can be mainly categorized as (i) changes in the cell wall or plasma membrane, which lead to impaired drug (azole) uptake; (ii) alterations in the affinity of the drug target Erg11p (lanosterol 14alpha-demethylase) especially to azoles or in the cellular content of Erg11p due to target site mutation or overexpression of the ERG11 gene; and (iii) the efflux of drugs mediated by membrane transport proteins belonging to the ATP-binding cassette (ABC) transporters, namely CDR1 and CDR2 or to the major facilitator superfamily (MFS) transporter, CaMDR1. Many such manifestations are associated with the formation of Candida biofilms including those occurring on devices like indwelling intravascular catheters. Biofilm-associated Candida show uniform resistance to a wide spectrum of antifungal drugs. A combination of different resistance mechanisms is responsible for drug resistance in clinical isolates of Candida species. PMID:17896473

  18. Delimitation of Neonectria and Cylindrocarpon (Nectriaceae, Hypocreales, Ascomycota) and related genera with Cylindrocarpon-like anamorphs

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Neonectria is a cosmopolitan genus and it is, in part, defined by its link to the anamorph genus Cylindrocarpon. Neonectria has been divided into informal groups on the basis of combined morphology of anamorph and teleomorph. Forty years ago Booth divided Cylindrocarpon into four groups defined by p...

  19. Multigene phylogeny and taxonomic revision of yeasts and related fungi in the Ustilaginomycotina.

    PubMed

    Wang, Q-M; Begerow, D; Groenewald, M; Liu, X-Z; Theelen, B; Bai, F-Y; Boekhout, T

    2015-06-01

    The subphylum Ustilaginomycotina (Basidiomycota, Fungi) comprises mainly plant pathogenic fungi (smuts). Some of the lineages possess cultivable unicellular stages that are usually classified as yeast or yeast-like species in a largely artificial taxonomic system which is independent from and largely incompatible with that of the smut fungi. Here we performed phylogenetic analyses based on seven genes including three nuclear ribosomal RNA genes and four protein coding genes to address the molecular phylogeny of the ustilaginomycetous yeast species and their filamentous counterparts. Taxonomic revisions were proposed to reflect this phylogeny and to implement the 'One Fungus = One Name' principle. The results confirmed that the yeast-containing classes Malasseziomycetes, Moniliellomycetes and Ustilaginomycetes are monophyletic, whereas Exobasidiomycetes in the current sense remains paraphyletic. Four new genera, namely Dirkmeia gen. nov., Kalmanozyma gen. nov., Golubevia gen. nov. and Robbauera gen. nov. are proposed to accommodate Pseudozyma and Tilletiopsis species that are distinct from the other smut taxa and belong to clades that are separate from those containing type species of the hitherto described genera. Accordingly, new orders Golubeviales ord. nov. with Golubeviaceae fam. nov. and Robbauerales ord. nov. with Robbaueraceae fam. nov. are proposed to accommodate the sisterhood of Golubevia gen. nov. and Robbauera gen. nov. with other orders of Exobasidiomycetes. The majority of the remaining anamorphic yeast species are transferred to corresponding teleomorphic genera based on strongly supported phylogenetic affinities, resulting in the proposal of 28 new combinations. The taxonomic status of a few Pseudozyma species remains to be determined because of their uncertain phylogenetic positions. We propose to use the term pro tempore or pro tem. in abbreviation to indicate the single-species lineages that are temporarily maintained. PMID:26955198

  20. Multigene phylogeny and taxonomic revision of yeasts and related fungi in the Ustilaginomycotina

    PubMed Central

    Wang, Q.-M.; Begerow, D.; Groenewald, M.; Liu, X.-Z.; Theelen, B.; Bai, F.-Y.; Boekhout, T.

    2015-01-01

    The subphylum Ustilaginomycotina (Basidiomycota, Fungi) comprises mainly plant pathogenic fungi (smuts). Some of the lineages possess cultivable unicellular stages that are usually classified as yeast or yeast-like species in a largely artificial taxonomic system which is independent from and largely incompatible with that of the smut fungi. Here we performed phylogenetic analyses based on seven genes including three nuclear ribosomal RNA genes and four protein coding genes to address the molecular phylogeny of the ustilaginomycetous yeast species and their filamentous counterparts. Taxonomic revisions were proposed to reflect this phylogeny and to implement the ‘One Fungus = One Name’ principle. The results confirmed that the yeast-containing classes Malasseziomycetes, Moniliellomycetes and Ustilaginomycetes are monophyletic, whereas Exobasidiomycetes in the current sense remains paraphyletic. Four new genera, namely Dirkmeia gen. nov., Kalmanozyma gen. nov., Golubevia gen. nov. and Robbauera gen. nov. are proposed to accommodate Pseudozyma and Tilletiopsis species that are distinct from the other smut taxa and belong to clades that are separate from those containing type species of the hitherto described genera. Accordingly, new orders Golubeviales ord. nov. with Golubeviaceae fam. nov. and Robbauerales ord. nov. with Robbaueraceae fam. nov. are proposed to accommodate the sisterhood of Golubevia gen. nov. and Robbauera gen. nov. with other orders of Exobasidiomycetes. The majority of the remaining anamorphic yeast species are transferred to corresponding teleomorphic genera based on strongly supported phylogenetic affinities, resulting in the proposal of 28 new combinations. The taxonomic status of a few Pseudozyma species remains to be determined because of their uncertain phylogenetic positions. We propose to use the term pro tempore or pro tem. in abbreviation to indicate the single-species lineages that are temporarily maintained. PMID:26955198

  1. Influence of nitrogen sources on growth and fermentation performance of different wine yeast species during alcoholic fermentation.

    PubMed

    Kemsawasd, Varongsiri; Viana, Tiago; Ardö, Ylva; Arneborg, Nils

    2015-12-01

    In this study, the influence of twenty different single (i.e. 19 amino acids and ammonium sulphate) and two multiple nitrogen sources (N-sources) on growth and fermentation (i.e. glucose consumption and ethanol production) performance of Saccharomyces cerevisiae and of four wine-related non-Saccharomyces yeast species (Lachancea thermotolerans, Metschnikowia pulcherrima, Hanseniaspora uvarum and Torulaspora delbrueckii) was investigated during alcoholic fermentation. Briefly, the N-sources with beneficial effects on all performance parameters (or for the majority of them) for each yeast species were alanine, arginine, asparagine, aspartic acid, glutamine, isoleucine, ammonium sulphate, serine, valine and mixtures of 19 amino acids and of 19 amino acids plus ammonium sulphate (for S. cerevisiae), serine (for L. thermotolerans), alanine (for H. uvarum), alanine and asparagine (for M. pulcherrima), arginine, asparagine, glutamine, isoleucine and mixture of 19 amino acids (for T. delbrueckii). Furthermore, our results showed a clear positive effect of complex mixtures of N-sources on S. cerevisiae and on T. delbrueckii (although to a lesser extent) as to all performance parameters studied, whereas for L. thermotolerans, H. uvarum and M. pulcherrima, single amino acids affected growth and fermentation performance to the same extent as the mixtures. Moreover, we found groups of N-sources with similar effects on the growth and/or fermentation performance of two or more yeast species. Finally, the influences of N-sources observed for T. delbrueckii and H. uvarum resembled those of S. cerevisiae the most and the least, respectively. Overall, this work contributes to an improved understanding of how different N-sources affect growth, glucose consumption and ethanol production of wine-related yeast species under oxygen-limited conditions, which, in turn, may be used to, e.g. optimize growth and fermentation performance of the given yeast upon N-source supplementation during

  2. An improved high-throughput Nile red fluorescence assay for estimating intracellular lipids in a variety of yeast species

    PubMed Central

    Sitepu, I.R.; Ignatia, L.; Franz, A. K.; Wong, D. M.; Faulina, S.A.; Tsui, M.; Kanti, A.; Boundy-Mills, K.

    2012-01-01

    A rapid and inexpensive method for estimating lipid content of yeasts is needed for screening large numbers of yeasts samples. Nile red is a fluorescent lipophilic dye used for detection and quantification of intracellular lipid droplets in various biological system including algae, yeasts and filamentous fungi. However, a published assay for yeast is affected by variable diffusion across the cell membrane, and variation in the time required to reach maximal fluorescence emission. In this study, parameters that may influence the emission were varied to determine optimal assay conditions. An improved assay with a high-throughput capability was developed that includes the addition of dimethyl sulfoxide (DMSO) solvent to improve cell permeability, elimination of the washing step, the reduction of Nile red concentration, kinetic readings rather than single time-point reading, and utilization of a black 96-well microplate. The improved method was validated by comparison to gravimetric determination of lipid content of a broad variety of ascomycete and basidiomycete yeast species. PMID:22985718

  3. Description of Scheffersomyces henanensis sp. nov., a New D-Xylose-Fermenting Yeast Species Isolated from Rotten Wood

    PubMed Central

    Ren, Yongcheng; Chen, Liang; Niu, Qiuhong; Hui, Fengli

    2014-01-01

    Two strains of a D-xylose-fermenting yeast species were isolated from rotten wood samples collected from the Baotianman Nature Reserve in Henan Province, central China. These strains formed hat-shaped ascospores in conjugated and deliquescent asci. Multilocus phylogenetic analysis that included the nearly complete small subunit (SSU), the internal transcribed spacer (ITS) region and the D1/D2 domain of the large subunit (LSU) rRNA genes, as well as RNA polymerase II largest subunit (RPB1) gene demonstrated that the two strains represent a novel yeast species closely related to Scheffersomyces segobiensis. A sequence comparison of xylose reductase (XYL1) gene, which was recently recommended for rapid identification of cryptic species in the Scheffersomyces clade, revealed a significant sequence divergence of 25 nucleotides between the novel strains and their closest relative S. segobiensis, supporting their classification as a distinct species. Furthermore, these new strains can be clearly distinguished from S. segobiensis by a number of morphological and physiological characteristics. Therefore, a novel yeast species, Scheffersomyces henanensis sp. nov., is proposed to accommodate these strains. The type strain is BY-41T ( =  CICC 1974T  =  CBS 12475T). PMID:24647466

  4. Description of Scheffersomyces henanensis sp. nov., a new D-xylose-fermenting yeast species isolated from rotten wood.

    PubMed

    Ren, Yongcheng; Chen, Liang; Niu, Qiuhong; Hui, Fengli

    2014-01-01

    Two strains of a D-xylose-fermenting yeast species were isolated from rotten wood samples collected from the Baotianman Nature Reserve in Henan Province, central China. These strains formed hat-shaped ascospores in conjugated and deliquescent asci. Multilocus phylogenetic analysis that included the nearly complete small subunit (SSU), the internal transcribed spacer (ITS) region and the D1/D2 domain of the large subunit (LSU) rRNA genes, as well as RNA polymerase II largest subunit (RPB1) gene demonstrated that the two strains represent a novel yeast species closely related to Scheffersomyces segobiensis. A sequence comparison of xylose reductase (XYL1) gene, which was recently recommended for rapid identification of cryptic species in the Scheffersomyces clade, revealed a significant sequence divergence of 25 nucleotides between the novel strains and their closest relative S. segobiensis, supporting their classification as a distinct species. Furthermore, these new strains can be clearly distinguished from S. segobiensis by a number of morphological and physiological characteristics. Therefore, a novel yeast species, Scheffersomyces henanensis sp. nov., is proposed to accommodate these strains. The type strain is BY-41T ( =  CICC 1974T  =  CBS 12475T). PMID:24647466

  5. Use of PCR-restriction fragment length polymorphism analysis for identification of yeast species isolated from bovine intramammary infection.

    PubMed

    Fadda, M E; Pisano, M B; Scaccabarozzi, L; Mossa, V; Deplano, M; Moroni, P; Liciardi, M; Cosentino, S

    2013-01-01

    This study reports a rapid PCR-based technique using a one-enzyme RFLP for discrimination of yeasts isolated from bovine clinical and subclinical mastitis milk samples. We analyzed a total of 1,486 milk samples collected over 1 yr in south Sardinia and northern Italy, and 142 yeast strains were preliminarily grouped based on their cultural morphology and physiological characteristics. Assimilation tests were conducted using the identification kit API ID 32C and APILAB Plus software (bioMérieux, Marcy l'Etoile, France). For PCR-RFLP analysis, the 18S-ITS1-5.8S ribosomal(r)DNA region was amplified and then digested with HaeIII, and dendrogram analysis of RFLP fragments was carried out. Furthermore, within each of the groups identified by the API or PCR-RFLP methods, the identification of isolates was confirmed by sequencing of the D1/D2 region using an ABI Prism 310 automatic sequencer (Applied Biosystems, Foster City, CA). The combined phenotypic and molecular approach enabled the identification of 17 yeast species belonging to the genera Candida (47.9%), Cryptococcus (21.1%), Trichosporon (19.7%), Geotrichum (7.1%), and Rhodotorula (4.2%). All Candida species were correctly identified by the API test and their identification confirmed by sequencing. All strains identified with the API system as Geotrichum candidum, Cryptococcus uniguttulatus, and Rhodotorula glutinis also produced characteristic restriction patterns and were confirmed as Galactomyces geotrichum (a teleomorph of G. candidum), Filobasidium uniguttulatum (teleomorph of Crypt. uniguttulatus), and R. glutinis, respectively, by D1/D2 rDNA sequencing. With regard to the genus Trichosporon, preliminary identification by API was problematic, whereas the RFLP technique used in this study gave characteristic restriction profiles for each species. Moreover, sequencing of the D1/D2 region allowed not only successful identification of Trichosporon gracile where API could not, but also correct identification of

  6. Three common bryophilous fungi with meristematic anamorphs and phylogenetic alliance to Teratosphaeriaceae, Capnodiales.

    PubMed

    Wäli, Pauliina P; Huhtinen, Seppo; Pino-Bodas, Raquel; Stenroos, Soili

    2014-12-01

    Bryophilous ascomycetes are an overlooked and poorly known fungal group. In this study, the extreme and small-sized niche of Polytrichum piliferum hyaline leaf tips was screened for the presence of these fungi in Finland. Three closely related species were found. Bryochiton perpusillus and Bryochiton monascus were identified from several samples, and DNA isolations revealed a third closely related species, Bryochiton sp. In addition, melanised hyphae, typical to the Bryochiton species, were present in all the samples. According to phylogenetic analyses consisting of combined small subunit (SSU), large subunit (LSU), and 5.8S rDNA sequences, and internal transcribed spacer (ITS) rDNA sequences, the species showed affinity with Teratosphaeriaceae within Capnodiales, and especially with black, meristematic species often inhabiting rock substrate in extreme environments. The connection was supported by meristematic growth of the Bryochiton species in culture. Bryochiton is the second sexual genus associated within the family Teratosphaeriaceae, and B. perpusillus, and B. monascus constitute examples of teleomorphs within a group of meristematic anamorphs. These findings emphasize the multiform diversity underlying poorly researched fungal groups, such as the bryophilous fungi. PMID:25457943

  7. Action of reactive oxygen species in the antifungal mechanism of gemini-pyridinium salts against yeast.

    PubMed

    Shirai, Akihiro; Ueta, Shouko; Maseda, Hideaki; Kourai, Hiroki; Omasa, Takeshi

    2012-06-01

    We previously found that the gemini quaternary salt (gemini-QUAT) containing two pyridinium residues per molecule, 3,3'- (2,7-dioxaoctane) bis (1-decylpyridinium bromide) (3DOBP-4,10) , exerted fungicidal activity against Saccharomyces cerevisiae and caused respiration inhibition and the cytoplasmic leakage of ATP, magnesium, and potassium ions. Here, we investigated how the gemini-QUAT, 3DOBP-4,10, exerts more powerful antimicrobial activity than the mono-QUAT N-cetylpyridinium chloride (CPC) and examined the association between reactive oxygen species (ROS) and the antimicrobial mechanism. Antifungal assays showed that the activity of 3DOBP-4,10 against two yeasts, S. cerevisiae and Candida albicans, was significantly elevated under aerobic conditions, and largely reduced under anaerobic conditions (nitrogen atmosphere) . Adding radical scavengers such as superoxide dismutase, catalase and potassium iodide (KI) also decreased the fungicidal activity of 3DOBP-4,10 but negligibly affected that of CPC. We measured survival under static conditions and found that the rapid fungicidal profile of 3DOBP-4,10 was lost, whereas that of CPC was slightly affected in the presence of KI. Our results suggest that 3DOBP-4,10 exerts powerful antimicrobial activity by penetrating the cell wall and membrane, which then allows oxygen to enter the cells, where it participates in the generation of intracellular ROS. The activity could thus be attributable to a synergic antimicrobial combination of the disruption of organelle membranes by the QUAT and oxidative stress imposed by ROS. PMID:22790843

  8. Prevalence and Dynamics of Ribosomal DNA Micro-heterogeneity Are Linked to Population History in Two Contrasting Yeast Species.

    PubMed

    James, Stephen A; West, Claire; Davey, Robert P; Dicks, Jo; Roberts, Ian N

    2016-01-01

    Despite the considerable number and taxonomic breadth of past and current genome sequencing projects, many of which necessarily encompass the ribosomal DNA, detailed information on the prevalence and evolutionary significance of sequence variation in this ubiquitous genomic region are severely lacking. Here, we attempt to address this issue in two closely related yet contrasting yeast species, the baker's yeast Saccharomyces cerevisiae and the wild yeast Saccharomyces paradoxus. By drawing on existing datasets from the Saccharomyces Genome Resequencing Project, we identify a rich seam of ribosomal DNA sequence variation, characterising 1,068 and 970 polymorphisms in 34 S. cerevisiae and 26 S. paradoxus strains respectively. We discover the two species sets exhibit distinct mutational profiles. Furthermore, we show for the first time that unresolved rDNA sequence variation resulting from imperfect concerted evolution of the ribosomal DNA region follows a U-shaped allele frequency distribution in each species, similar to loci that evolve under non-concerted mechanisms but arising through rather different evolutionary processes. Finally, we link differences between the shapes of these allele frequency distributions to the two species' contrasting population histories. PMID:27345953

  9. Dual Double-Wedge Pseudo-Depolarizer with Anamorphic PSF

    NASA Technical Reports Server (NTRS)

    Hill, Peter; Thompson, Patrick

    2012-01-01

    A polarized scene, which may occur at oblique illumination angles, creates a radiometric signal that varies as a function of viewing angle. One common optical component that is used to minimize such an effect is a polarization scrambler or depolarizer. As part of the CLARREO mission, the SOLARIS instrument project at Goddard Space Flight Center has developed a new class of polarization scramblers using a dual double-wedge pseudo-depolarizer that produces an anamorphic point spread function (PSF). The SOLARIS instrument uses two Wollaston type scramblers in series, each with a distinct wedge angle, to image a pseudo-depolarized scene that is free of eigenstates. Since each wedge is distinct, the scrambler is able to produce an anamorphic PSF that maintains high spatial resolution in one dimension by sacrificing the spatial resolution in the other dimension. This scrambler geometry is ideal for 1-D imagers, such as pushbroom slit spectrometers, which require high spectral resolution, high spatial resolution, and low sensitivity to polarized light. Moreover, the geometry is applicable to a wide range of scientific instruments that require both high SNR (signal-to-noise ratio) and low sensitivity to polarized scenes

  10. Moniliella carnis sp. nov. and Moniliella dehoogii sp. nov., two novel species of black yeasts isolated from meat processing environments.

    PubMed

    Thanh, Vu Nguyen; Hai, Dao Anh; Hien, Dinh Duc; Takashima, Masako; Lachance, Marc-André

    2012-12-01

    Thirteen strains of yeasts typical of the genus Moniliella were isolated from fermenting meat and meat processing tools in Vietnam. PCR fingerprints generated by primer (GAC)(5) subdivided the strains into two distinctive genetic groups. In a phylogenetic tree based on D1/D2 large subunit rRNA gene sequences, the strains formed a well-supported clade with Moniliella spathulata and Moniliella suaveolens but represented two new lineages. The names Moniliella carnis sp. nov. and Moniliella dehoogii sp. nov. are proposed. The two novel species can be distinguished from each other and from known species of Moniliella based on phenotypic characteristics. It is assumed that the yeasts were associated with fatty substances that contaminated the meat processing tools. The type strain of Moniliella carnis is KFP 246(T) ( = CBS 126447(T) = NRRL Y-48681(T)) and the type strain of Moniliella dehoogii is KFP 211(T) ( = CBS 126564(T) = NRRL Y-48682(T)). PMID:22863989

  11. Looking beyond Saccharomyces: the potential of non-conventional yeast species for desirable traits in bioethanol fermentation.

    PubMed

    Radecka, Dorota; Mukherjee, Vaskar; Mateo, Raquel Quintilla; Stojiljkovic, Marija; Foulquié-Moreno, María R; Thevelein, Johan M

    2015-09-01

    Saccharomyces cerevisiae has been used for millennia in the production of food and beverages and is by far the most studied yeast species. Currently, it is also the most used microorganism in the production of first-generation bioethanol from sugar or starch crops. Second-generation bioethanol, on the other hand, is produced from lignocellulosic feedstocks that are pretreated and hydrolyzed to obtain monomeric sugars, mainly D-glucose, D-xylose and L-arabinose. Recently, S. cerevisiae recombinant strains capable of fermenting pentose sugars have been generated. However, the pretreatment of the biomass results in hydrolysates with high osmolarity and high concentrations of inhibitors. These compounds negatively influence the fermentation process. Therefore, robust strains with high stress tolerance are required. Up to now, more than 2000 yeast species have been described and some of these could provide a solution to these limitations because of their high tolerance to the most predominant stress conditions present in a second-generation bioethanol reactor. In this review, we will summarize what is known about the non-conventional yeast species showing unusual tolerance to these stresses, namely Zygosaccharomyces rouxii (osmotolerance), Kluyveromyces marxianus and Ogataea (Hansenula) polymorpha (thermotolerance), Dekkera bruxellensis (ethanol tolerance), Pichia kudriavzevii (furan derivatives tolerance) and Z. bailii (acetic acid tolerance). PMID:26126524

  12. Prevalence and Dynamics of Ribosomal DNA Micro-heterogeneity Are Linked to Population History in Two Contrasting Yeast Species

    PubMed Central

    James, Stephen A.; West, Claire; Davey, Robert P.; Dicks, Jo; Roberts, Ian N.

    2016-01-01

    Despite the considerable number and taxonomic breadth of past and current genome sequencing projects, many of which necessarily encompass the ribosomal DNA, detailed information on the prevalence and evolutionary significance of sequence variation in this ubiquitous genomic region are severely lacking. Here, we attempt to address this issue in two closely related yet contrasting yeast species, the baker’s yeast Saccharomyces cerevisiae and the wild yeast Saccharomyces paradoxus. By drawing on existing datasets from the Saccharomyces Genome Resequencing Project, we identify a rich seam of ribosomal DNA sequence variation, characterising 1,068 and 970 polymorphisms in 34 S. cerevisiae and 26 S. paradoxus strains respectively. We discover the two species sets exhibit distinct mutational profiles. Furthermore, we show for the first time that unresolved rDNA sequence variation resulting from imperfect concerted evolution of the ribosomal DNA region follows a U-shaped allele frequency distribution in each species, similar to loci that evolve under non-concerted mechanisms but arising through rather different evolutionary processes. Finally, we link differences between the shapes of these allele frequency distributions to the two species’ contrasting population histories. PMID:27345953

  13. High-throughput fluorescence screening assay for the identification and comparison of antimicrobial peptides' activity on various yeast species.

    PubMed

    Kodedová, Marie; Sychrová, Hana

    2016-09-10

    New antifungal compounds that circumvent the resistance of the pathogen by directly damaging yeast cell surface structures are promising agents for the treatment of fungal infections, due to their different mechanism of action from current clinically used antifungal drugs. We present here a rapid and cost-effective fluorescence method suitable for identifying new potent drugs that directly target yeast cell surface structures, causing cell permeabilization and thus bypassing the multidrug resistance mechanisms of pathogens. The fluorescence assay enabled us to detect with high sensitivity damage to the Candida plasma membrane (its hyperpolarization and permeabilization) as a result of short-term exposure to the antifungal compounds. Results can be obtained in 1-2h with minimal effort and consumption of the tested compounds, also 96 samples can be analysed simultaneously. We used this method to study antimicrobial peptides isolated from the venom of bees and their synthetic analogs, compare the potency of the peptides and determine their minimal effective concentrations. The antimicrobial peptides were able to kill yeast cells at low concentrations within a 15-min treatment, the LL-III peptide exhibited a broad spectrum of antifungal activity on various Saccharomyces, pathogenic Candida and osmotolerant yeast species. PMID:27369550

  14. Development of two molecular approaches for differentiation of clinically relevant yeast species closely related to Candida guilliermondii and Candida famata.

    PubMed

    Feng, Xiaobo; Wu, Jingsong; Ling, Bo; Yang, Xianwei; Liao, Wanqing; Pan, Weihua; Yao, Zhirong

    2014-09-01

    The emerging pathogens Candida palmioleophila, Candida fermentati, and Debaryomyces nepalensis are often misidentified as Candida guilliermondii or Candida famata in the clinical laboratory. Due to the significant differences in antifungal susceptibilities and epidemiologies among these closely related species, a lot of studies have focused on the identification of these emerging yeast species in clinical specimens. Nevertheless, limited tools are currently available for their discrimination. Here, two new molecular approaches were established to distinguish these closely related species. The first approach differentiates these species by use of restriction fragment length polymorphism analysis of partial internal transcribed spacer 2 (ITS2) and large subunit ribosomal DNA with the enzymes BsaHI and XbaI in a double digestion. The second method involves a multiplex PCR based on the intron size differences of RPL18, a gene coding for a protein component of the large (60S) ribosomal subunit, and species-specific amplification. These two methods worked well in differentiation of these closely related yeast species and have the potential to serve as effective molecular tools suitable for laboratory diagnoses and epidemiological studies. PMID:24951804

  15. Spathaspora allomyrinae sp. nov., a d-xylose-fermenting yeast species isolated from a scarabeid beetle Allomyrina dichotoma.

    PubMed

    Wang, Yun; Ren, Yong-Cheng; Zhang, Zheng-Tian; Ke, Tao; Hui, Feng-Li

    2016-05-01

    During an investigation of yeasts associated with insects, three strains of a d-xylose-fermenting yeast species were isolated from the gut of the host beetles Allomyrina dichotoma (Coleoptera: Scarabeidae) collected on the Baotianman National Nature Reserve, Nanyan, Henan Province, China. These strains formed two elongated ascospores, which were tapered and curved at the ends in persistent asci. Sequence analyses of the D1/D2 domains of the large subunit (LSU) and small subunit (SSU) rRNA genes showed that these new strains represent a phylogenetically distinct species in the Spathaspora clade. This novel species differed from the closest species, Candida lyxosophila NRRL Y-17539T, by a 6.7 % sequence divergence (31 substitutions and 7 gaps) in the D1/D2 LSU rRNA gene and a 1.2 % divergence (17 substitutions, 4 gaps) in the SSU rRNA gene. The novel species can also be distinguished from C. lyxosophila NRRL Y-17539T in terms of the ability to assimilate myo-inositol and to grow in the presence of 0.1 % cycloheximide, as well as the inability to assimilate citrate. The name Spathaspora allomyrinae sp. nov. is proposed for this species. The type strain is NYNU 1495T ( = CICC 33057T = CBS 13924T). The MycoBank number is MB 815071. PMID:26895992

  16. Taxonomy, nomenclature and phylogeny of three cladosporium-like hyphomycetes, Sorocybe resinae, Seifertia azaleae and the Hormoconis anamorph of Amorphotheca resinae

    PubMed Central

    Seifert, K.A.; Hughes, S.J.; Boulay, H.; Louis-Seize, G.

    2007-01-01

    Using morphological characters, cultural characters, large subunit and internal transcribed spacer rDNA (ITS) sequences, and provisions of the International Code of Botanical Nomenclature, this paper attempts to resolve the taxonomic and nomenclatural confusion surrounding three species of cladosporium-like hyphomycetes. The type specimen of Hormodendrum resinae, the basis for the use of the epithet resinae for the creosote fungus {either as Hormoconis resinae or Cladosporium resinae) represents the mononematous synanamorph of the synnematous, resinicolous fungus Sorocybe resinae. The phylogenetic relationships of the creosote fungus, which is the anamorph of Amorphotheca resinae, are with the family Myxotrichaceae, whereas S. resinae is related to Capronia (Chaetothyriales, Herpotrichiellaceae). Our data support the segregation of Pycnostysanus azaleae, the cause of bud blast of rhododendrons, in the recently described anamorph genus Seifertia, distinct from Sorocybe; this species is related to the Dothideomycetes but its exact phylogenetic placement is uncertain. To formally stabilize the name of the anamorph of the creosote fungus, conservation of Hormodendrum resinae with a new holotype should be considered. The paraphyly of the family Myxotrichaceae with the Amorphothecaceae suggested by ITS sequences should be confirmed with additional genes. PMID:18491002

  17. Lipolytic activity of the yeast species associated with the fermentation/storage phase of ripe olive processing.

    PubMed

    Rodríguez-Gómez, F; Arroyo-López, F N; López-López, A; Bautista-Gallego, J; Garrido-Fernández, A

    2010-08-01

    Ripe olives account for ca. 30% of the world's table olive production. Fruits intended for this type of product are preserved in an aqueous solution (acidic water or brine) for several months, where they may undergo a spontaneous fermentation. Enterobacteriaceae and lactic acid bacteria were not detected in the present survey during storage. Thus, the work focused on studying the yeast microflora associated with the ripe olive storage of Manzanilla and Hojiblanca cultivars in acidified brines. A total of 90 yeast isolates were identified by means of molecular methods using RFLP analysis of the 5.8S-ITS rDNA region and sequencing of the D1/D2 domains of the 26S rDNA gene. The two most important species identified in both cultivars were Saccharomyces cerevisiae and Pichia galeiformis, which were present throughout the storage period, while Candida boidinii was detected during the later stages of the process. The species Pichia membranifaciens was detected only in the early stages of the Hojiblanca cultivar. The lipase assays performed with both extracellular and whole cell fractions of the yeast isolates showed that neither of the S. cerevisiae and P. galeiformis species had lipase activity, while the P. membranifaciens isolates showed a weak activity. On the contrary, all C. boidinii isolates gave a strong lipase activity. Change in olive fat acidity was markedly higher in the presence of the yeast population than in sterile storage, indicating that lipases produced by these microorganisms modify the characteristics of the fat in the fruit. PMID:20510778

  18. Yamadazyma insecticola f.a., sp. nov. and Yamadazyma epiphylla f.a., sp. nov., two novel yeast species.

    PubMed

    Jindamorakot, Sasitorn; Am-In, Somjit; Kaewwichian, Rungluk; Limtong, Savitree

    2015-04-01

    Two yeast strains representing two novel yeast species were isolated from frass of an unidentified insect (ST-78(T)) and the external surfaces of rice leaves (YE170(T)) collected in Thailand. The two strains were genetically, morphologically and phenotypically distinct from recognized species and were found to represent two novel species of the genus Yamadazyma although formation of ascospores was not observed. In terms of pairwise sequence similarity of the D1/D2 region of the large subunit rRNA gene, the closest relative of strain ST-78(T) was Candida lessepsii CBS 9941(T) but with 3.8% nucleotide substitutions, while the closest relative of strain YE170(T) was strain ST-78(T) but with 4.3% nucleotide substitutions. Analysis of the sequences of the internal transcribed spacer 1 and 2 (ITS1-2) regions revealed that strain ST-78 differed from C. lessepsii CBS 9941(T) by 8.8% nucleotide substitutions and from strain YE170(T) by 9.4% nucleotide substitutions. The result of pairwise sequence similarity of the D1/D2 and ITS1-2 regions together with phylogenetic analysis indicated that strains ST-78(T) and YE170(T) represented two novel species within the Yamadazyma clade. The names Yamadazyma insecticola f.a., sp. nov. (type strain ST-78(T) = BCC 8314(T) = NBRC 110421(T) = CBS 13382(T); MycoBank no. MB810546) and Yamadazyma epiphylla f.a., sp. nov. (type strain YE170(T) = BCC 63466(T) = NBRC 110423(T) = CBS 13384(T); MycoBank no. MB810547) are proposed for the two novel yeast species. PMID:25644483

  19. Measurement of steep aspheric surfaces using an anamorphic probe

    NASA Astrophysics Data System (ADS)

    Biswas, Amiya; Coupland, Jeremy

    2008-04-01

    Synthetic aperture interferometry has been previously proposed as a possible in-process method to measure aspheric form (R. Tomlinson, Appl. Opt.42, 701, 2003.APOPAI0003-693510.1364/AO.42.000701). Preliminary demonstration utilized a scanning probe consisting of a pair of bare single mode fibers to perform source and receive functions. It was found that this probe did not have sufficient numerical aperture (NA) to measure steep surfaces and that simply increasing the NA decreases the light gathering efficiency substantially. In this paper, we introduce supplementary optics to increase the NA, and the light gathering efficiency has been increased by adopting an anamorphic design. A spherical test optic of known form is measured to demonstrate the capability of the new probe design.

  20. Anamorphic transformation and its application to time-bandwidth compression.

    PubMed

    Asghari, Mohammad H; Jalali, Bahram

    2013-09-20

    A general method for compressing the modulation time-bandwidth product of analog signals is introduced. As one of its applications, this physics-based signal grooming, performed in the analog domain, allows a conventional digitizer to sample and digitize the analog signal with variable resolution. The net result is that frequency components that were beyond the digitizer bandwidth can now be captured and, at the same time, the total digital data size is reduced. This compression is lossless and is achieved through a feature selective reshaping of the signal's complex field, performed in the analog domain prior to sampling. Our method is inspired by operation of Fovea centralis in the human eye and by anamorphic transformation in visual arts. The proposed transform can also be performed in the digital domain as a data compression algorithm to alleviate the storage and transmission bottlenecks associated with "big data." PMID:24085172

  1. Spathaspora arborariae sp. nov., a d-xylose-fermenting yeast species isolated from rotting wood in Brazil.

    PubMed

    Cadete, Raquel M; Santos, Renata O; Melo, Monaliza A; Mouro, Adriane; Gonçalves, Davi L; Stambuk, Boris U; Gomes, Fátima C O; Lachance, Marc-André; Rosa, Carlos A

    2009-12-01

    Four strains of a new yeast species were isolated from rotting wood from two sites in an Atlantic Rain Forest and a Cerrado ecosystem in Brazil. The analysis of the sequences of the D1/D2 domains of the large-subunit rRNA gene showed that this species belongs to the Spathaspora clade. The new species ferments D-xylose efficiently and is related to Candida jeffriesii and Spathaspora passalidarum, both of which also ferment D-xylose. Similar to S. passalidarum, the new species produces unconjugated asci with a single greatly elongated ascospore with curved ends. The type strain of Spathaspora arborariae sp. nov. is UFMG-HM19.1A(T) (=CBS11463(T)=NRRL Y-48658(T)). PMID:19840117

  2. Phylogenetic classification of yeasts and related taxa within Pucciniomycotina.

    PubMed

    Wang, Q-M; Yurkov, A M; Göker, M; Lumbsch, H T; Leavitt, S D; Groenewald, M; Theelen, B; Liu, X-Z; Boekhout, T; Bai, F-Y

    2015-06-01

    Most small genera containing yeast species in the Pucciniomycotina (Basidiomycota, Fungi) are monophyletic, whereas larger genera including Bensingtonia, Rhodosporidium, Rhodotorula, Sporidiobolus and Sporobolomyces are polyphyletic. With the implementation of the "One Fungus = One Name" nomenclatural principle these polyphyletic genera were revised. Nine genera, namely Bannoa, Cystobasidiopsis, Colacogloea, Kondoa, Erythrobasidium, Rhodotorula, Sporobolomyces, Sakaguchia and Sterigmatomyces, were emended to include anamorphic and teleomorphic species based on the results obtained by a multi-gene phylogenetic analysis, phylogenetic network analyses, branch length-based methods, as well as morphological, physiological and biochemical comparisons. A new class Spiculogloeomycetes is proposed to accommodate the order Spiculogloeales. The new families Buckleyzymaceae with Buckleyzyma gen. nov., Chrysozymaceae with Chrysozyma gen. nov., Microsporomycetaceae with Microsporomyces gen. nov., Ruineniaceae with Ruinenia gen. nov., Symmetrosporaceae with Symmetrospora gen. nov., Colacogloeaceae and Sakaguchiaceae are proposed. The new genera Bannozyma, Buckleyzyma, Fellozyma, Hamamotoa, Hasegawazyma, Jianyunia, Rhodosporidiobolus, Oberwinklerozyma, Phenoliferia, Pseudobensingtonia, Pseudohyphozyma, Sampaiozyma, Slooffia, Spencerozyma, Trigonosporomyces, Udeniozyma, Vonarxula, Yamadamyces and Yunzhangia are proposed to accommodate species segregated from the genera Bensingtonia, Rhodosporidium, Rhodotorula, Sporidiobolus and Sporobolomyces. Ballistosporomyces is emended and reintroduced to include three Sporobolomyces species of the sasicola clade. A total of 111 new combinations are proposed in this study. PMID:26951631

  3. Phylogenetic classification of yeasts and related taxa within Pucciniomycotina

    PubMed Central

    Wang, Q.-M.; Yurkov, A.M.; Göker, M.; Lumbsch, H.T.; Leavitt, S.D.; Groenewald, M.; Theelen, B.; Liu, X.-Z.; Boekhout, T.; Bai, F.-Y.

    2016-01-01

    Most small genera containing yeast species in the Pucciniomycotina (Basidiomycota, Fungi) are monophyletic, whereas larger genera including Bensingtonia, Rhodosporidium, Rhodotorula, Sporidiobolus and Sporobolomyces are polyphyletic. With the implementation of the “One Fungus = One Name” nomenclatural principle these polyphyletic genera were revised. Nine genera, namely Bannoa, Cystobasidiopsis, Colacogloea, Kondoa, Erythrobasidium, Rhodotorula, Sporobolomyces, Sakaguchia and Sterigmatomyces, were emended to include anamorphic and teleomorphic species based on the results obtained by a multi-gene phylogenetic analysis, phylogenetic network analyses, branch length-based methods, as well as morphological, physiological and biochemical comparisons. A new class Spiculogloeomycetes is proposed to accommodate the order Spiculogloeales. The new families Buckleyzymaceae with Buckleyzyma gen. nov., Chrysozymaceae with Chrysozyma gen. nov., Microsporomycetaceae with Microsporomyces gen. nov., Ruineniaceae with Ruinenia gen. nov., Symmetrosporaceae with Symmetrospora gen. nov., Colacogloeaceae and Sakaguchiaceae are proposed. The new genera Bannozyma, Buckleyzyma, Fellozyma, Hamamotoa, Hasegawazyma, Jianyunia, Rhodosporidiobolus, Oberwinklerozyma, Phenoliferia, Pseudobensingtonia, Pseudohyphozyma, Sampaiozyma, Slooffia, Spencerozyma, Trigonosporomyces, Udeniozyma, Vonarxula, Yamadamyces and Yunzhangia are proposed to accommodate species segregated from the genera Bensingtonia, Rhodosporidium, Rhodotorula, Sporidiobolus and Sporobolomyces. Ballistosporomyces is emended and reintroduced to include three Sporobolomyces species of the sasicola clade. A total of 111 new combinations are proposed in this study. PMID:26951631

  4. Detection of yeast species also occurring in substrates associated with animals and identification of a novel dimorphic species in Verbascum flowers from Georgia.

    PubMed

    Sipiczki, Matthias

    2013-03-01

    The molecular taxonomic analysis of yeasts isolated from Verbascum flowers collected in central Georgia identified strains that could be assigned to the species Cryptococcus adeliensis, Cryptococcus magnus and Moniliella megachiliensis detected previously also in substrates associated with insects and other animals and a hitherto undescribed species for which the name Candida verbasci is proposed. The new species forms slightly pink colonies, propagates by mostly unipolar budding, forms invasive pseudomycelium, and the sequences of its D1/D2 LSU rRNA genes and ITS1-5.8S-ITS2 regions indicate close phylogenetic relationship with a group of species that form a cluster basal to the Candida albicans/Lodderomyces elongisporus clade. The type strain is 11-1055(T). It has been deposited in Centralbureau voor Schimmelcultures (Utrecht, the Netherlands) as CBS 12699(T), the National Collection of Agricultural and Industrial Microorganisms (Budapest, Hungary) as NCAIM Y.02048(T) and the Culture Collection of Yeasts (Bratislava, Slovakia) as CCY 29-185-1(T). The GenBank accession numbers for nucleotide sequences of the C. verbasci type strain are: JX515981 (D1/D2 domain of the 26S rRNA gene) and JX515982 (ITS1-5.8S-ITS2). Mycobank: MB 801391. PMID:23114573

  5. Structural characterization of novel sophorolipid biosurfactants from a newly-identified species of Candida yeast

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The sophorolipids are a group of O-acylsophorose-based biosurfactants produced by several yeasts of the Starmerella clade. The known sophorolipids are typically partially acetylated 2-O-ß-D-glucopyranosyl-D-glucopyranose (sophorose) ß-O-glycosidically-linked to 17-L-hydroxy-delta-9-octadecenoic aci...

  6. Evaluation of PNA FISH® Yeast Traffic Light in identification of Candida species from blood and non-blood culture specimens.

    PubMed

    Radic, Marina; Goic-Barisic, Ivana; Novak, Anita; Rubic, Zana; Tonkic, Marija

    2016-08-01

    PNA FISH(®) (peptide nucleic acid fluorescent in situ hybridization) Yeast Traffic Light (PNA FISH(®) YTL) assay is a commercially avaliable method for rapid identification of Candida spp. directly from positive blood cultures. This report provides a one-year experience in identification of yeasts from 25 specimens (15 positive blood cultures and 10 other clinically significant specimens) using PNA FISH(®) YTL and comparing it to VITEK 2 System. Overall, assay identification compatibility with VITEK 2 System was found among 21/25 (84%) isolates tested. Only 3/25 (12%) of the isolates were not identified, and one isolate was misidentified by the PNA FISH(®) YTL assay. Our results show that the assay is a reliable method in identification of Candida spp. not only from blood cultures, but even from other clinically significant specimens (urine cultures, catheter tip cultures, peritoneal fluid cultures) when compared to automated method like VITEK 2 System. This novel application of the PNA FISH(®) YTL assay could therefore contribute to cost savings and significant benefit to patients, as rapid information about isolated yeast species is provided. PMID:27067303

  7. Rhodotorula svalbardensis sp. nov., a novel yeast species isolated from cryoconite holes of Ny-Ålesund, Arctic.

    PubMed

    Singh, Purnima; Singh, Shiv M; Tsuji, Masaharu; Prasad, Gandham S; Hoshino, Tamotsu

    2014-02-01

    A psychrophilic yeast species was isolated from glacier cryoconite holes of Svalbard. Nucleotide sequences of the strains were studied using D1/D2 domain, ITS region and partial sequences of mitochondrial cytochrome b gene. The strains belonged to a clade of psychrophilic yeasts, but showed marked differences from related species in the D1/D2 domain and biochemical characters. Effects of temperature, salt and media on growth of the cultures were also studied. Screening of the cultures for amylase, cellulase, protease, lipase, urease and catalase activities was carried out. The strains expressed high amylase and lipase activities. Freeze tolerance ability of the isolates indicated the formation of unique hexagonal ice crystal structures due to presence of 'antifreeze proteins' (AFPs). FAME analysis of cultures showed a unique trend of increase in unsaturated fatty acids with decrease in temperature. The major fatty acids recorded were oleic acid, linoleic acid, linolenic acid, palmitic acid, stearic acid, myristic acid and pentadecanoic acid. Based on sequence data and, physiological and morphological properties of the strains, we propose a novel species, Rhodotorula svalbardensis and designate strains MLB-I (CCP-II) and CRY-YB-1 (CBS 12863, JCM 19699, JCM 19700, MTCC 10952) as its type strains (Etymology: sval.bar.den'sis. N.L. fem. adj. svalbardensis pertaining to Svalbard). PMID:24463093

  8. Malassezia arunalokei sp. nov., a Novel Yeast Species Isolated from Seborrheic Dermatitis Patients and Healthy Individuals from India.

    PubMed

    Honnavar, Prasanna; Prasad, Gandham S; Ghosh, Anup; Dogra, Sunil; Handa, Sanjeev; Rudramurthy, Shivaprakash M

    2016-07-01

    The majority of species within the genus Malassezia are lipophilic yeasts that colonize the skin of warm-blooded animals. Two species, Malassezia globosa and Malassezia restricta, are implicated in the causation of seborrheic dermatitis/dandruff (SD/D). During our survey of SD/D cases, we isolated several species of Malassezia and noticed vast variations within a few lipid-dependent species. Variations observed in the phenotypic characteristics (colony morphology, absence of catalase activity, growth at 37°C, and precipitation surrounding wells containing Tween 20 or Cremophor EL) suggested the possible presence of a novel species. Sequence divergence observed in the internal transcribed spacer (ITS) region, the D1/D2 domain, and the intergenic spacer 1 (IGS1) region of rDNA and the TEF1 gene, PCR-restriction fragment length polymorphism (RFLP) analysis of the ITS2 region, and fluorescent amplified fragment length polymorphism analysis support the existence of a novel species. Based on phenotypic and molecular characterization of these strains, we propose a new species, namely, M. arunalokei sp. nov., and we designate NCCPF 127130 (= MTCC 12054 = CBS 13387) as the type strain. PMID:27147721

  9. Evolution and Ecophysiology of the Industrial Producer Hypocrea jecorina (Anamorph Trichoderma reesei) and a New Sympatric Agamospecies Related to It

    PubMed Central

    Druzhinina, Irina S.; Komoń-Zelazowska, Monika; Atanasova, Lea; Seidl, Verena; Kubicek, Christian P.

    2010-01-01

    Background Trichoderma reesei, a mitosporic green mould, was recognized during the WW II based on a single isolate from the Solomon Islands and since then used in industry for production of cellulases. It is believed to be an anamorph (asexual stage) of the common pantropical ascomycete Hypocrea jecorina. Methodology/Principal Findings We combined molecular evolutionary analysis and multiple methods of phenotype profiling in order to reveal the genetic relationship of T. reesei to H. jecorina. The resulting data show that the isolates which were previously identified as H. jecorina by means of morphophysiology and ITS1 and 2 (rRNA gene cluster) barcode in fact comprise several species: i) H. jecorina/T. reesei sensu stricto which contains most of the teleomorphs (sexual stages) found on dead wood and the wild-type strain of T. reesei QM 6a; ii) T. parareesei nom. prov., which contains all strains isolated as anamorphs from soil; iii) and two other hypothetical new species for which only one or two isolates are available. In silico tests for recombination and in vitro mating experiments revealed a history of sexual reproduction for H. jecorina and confirmed clonality for T. parareesei nom. prov. Isolates of both species were consistently found worldwide in pantropical climatic zone. Ecophysiological comparison of H. jecorina and T. parareesei nom. prov. revealed striking differences in carbon source utilization, conidiation intensity, photosensitivity and mycoparasitism, thus suggesting adaptation to different ecological niches with the high opportunistic potential for T. parareesei nom. prov. Conclusions Our data prove that T. reesei belongs to a holomorph H. jecorina and displays a history of worldwide gene flow. We also show that its nearest genetic neighbour - T. parareesei nom. prov., is a cryptic phylogenetic agamospecies which inhabits the same biogeographic zone. These two species thus provide a so far rare example of sympatric speciation within saprotrophic

  10. Sequencer-Based Capillary Gel Electrophoresis (SCGE) Targeting the rDNA Internal Transcribed Spacer (ITS) Regions for Accurate Identification of Clinically Important Yeast Species

    PubMed Central

    Chen, Sharon C.-A.; Wang, He; Zhang, Li; Fan, Xin; Xu, Zhi-Peng; Cheng, Jing-Wei; Kong, Fanrong; Zhao, Yu-Pei; Xu, Ying-Chun

    2016-01-01

    Accurate species identification of Candida, Cryptococcus, Trichosporon and other yeast pathogens is important for clinical management. In the present study, we developed and evaluated a yeast species identification scheme by determining the rDNA internal transcribed spacer (ITS) region length types (LTs) using a sequencer-based capillary gel electrophoresis (SCGE) approach. A total of 156 yeast isolates encompassing 32 species were first used to establish a reference SCGE ITS LT database. Evaluation of the ITS LT database was then performed on (i) a separate set of (n = 97) clinical isolates by SCGE, and (ii) 41 isolates of 41 additional yeast species from GenBank by in silico analysis. Of 156 isolates used to build the reference database, 41 ITS LTs were identified, which correctly identified 29 of the 32 (90.6%) species, with the exception of Trichosporon asahii, Trichosporon japonicum and Trichosporon asteroides. In addition, eight of the 32 species revealed different electropherograms and were subtyped into 2–3 different ITS LTs each. Of the 97 test isolates used to evaluate the ITS LT scheme, 96 (99.0%) were correctly identified to species level, with the remaining isolate having a novel ITS LT. Of the additional 41 isolates for in silico analysis, none was misidentified by the ITS LT database except for Trichosporon mucoides whose ITS LT profile was identical to that of Trichosporon dermatis. In conclusion, yeast identification by the present SCGE ITS LT assay is a fast, reproducible and accurate alternative for the identification of clinically important yeasts with the exception of Trichosporon species. PMID:27105313

  11. Molecular taxonomy of bambusicolous fungi: Tetraplosphaeriaceae, a new pleosporalean family with Tetraploa-like anamorphs

    PubMed Central

    Tanaka, K.; Hirayama, K.; Yonezawa, H.; Hatakeyama, S.; Harada, Y.; Sano, T.; Shirouzu, T.; Hosoya, T.

    2009-01-01

    A new pleosporalean family Tetraplosphaeriaceae is established to accommodate five new genera; 1) Tetraplosphaeria with small ascomata and anamorphs belonging to Tetraploa s. str., 2) Triplosphaeria characterised by hemispherical ascomata with rim-like side walls and anamorphs similar to Tetraploa but with three conidial setose appendages, 3) Polyplosphaeria with large ascomata surrounded by brown hyphae and anamorphs producing globose conidia with several setose appendages, 4) Pseudotetraploa, an anamorphic genus, having obpyriform conidia with pseudosepta and four to eight setose appendages, and 5) Quadricrura, an anamorphic genus, having globose conidia with one or two long setose appendages at the apex and four to five short setose appendages at the base. Fifteen new taxa in these genera mostly collected from bamboo are described and illustrated. They are linked by their Tetraploa s. l. anamorphs. To infer phylogenetic placement in the Pleosporales, analyses based on a combined dataset of small- and large-subunit nuclear ribosomal DNA (SSU+LSU nrDNA) was carried out. Tetraplosphaeriaceae, however, is basal to the main pleosporalean clade and therefore its relationship with other existing families was not completely resolved. To evaluate the validity of each taxon and to clarify the phylogenetic relationships within this family, further analyses using sequences from ITS-5.8S nrDNA (ITS), transcription elongation factor 1-α (TEF), and β-tubulin (BT), were also conducted. Monophyly of the family and that of each genus were strongly supported by analyses based on a combined dataset of the three regions (ITS+TEF+BT). Our results also suggest that Tetraplosphaeria (anamorph: Tetraploa s. str.) is an ancestral lineage within this family. Taxonomic placement of the bambusicolous fungi in Astrosphaeriella, Kalmusia, Katumotoa, Massarina, Ophiosphaerella, Phaeosphaeria, Roussoella, Roussoellopsis, and Versicolorisporium, are also discussed based on the SSU

  12. Determination and differentiation of triacylglycerol molecular species in Antarctic and non-Antarctic yeasts by atmospheric pressure-chemical ionization-mass spectrometry.

    PubMed

    Bhuiyan, Mohammad; Tucker, David; Watson, Kenneth

    2013-09-01

    Yeast, particularly Saccharomyces cerevisiae, has long served as a model eukaryotic system for studies on the regulation of lipid metabolism. We developed a high performance liquid chromatography-atmospheric pressure chemical ionization-mass spectrometry method for the detailed analysis of triacylglycerols (TAGs) in 14 species of yeast consisting of seven Antarctic yeasts (grown at 15°C and 5°C) and seven non-Antarctic yeasts (grown at 25°C and 15°C), the latter including 3 strains of S. cerevisiae. Analysis of TAG molecular species established that the sn-2 position was invariably occupied by an unsaturated fatty acyl moiety. In S. cerevisiae the preference was for oleic acid 18:1>palmitoleic acid 16:1, in Candida albicans, Cryptococcus humicolus and Rhodotorula mucilaginosa 18:1>linoleic acid 18:2 and in Zygosaccharomyces rouxii 18:2>18:1. In the Antarctic yeasts (Cryptococcus watticus, Cryptococcus victoriae, Cryptococcus nyarrowii, Leucosporidium antarcticum, Leucosporidium fellii, Candida psychrophila and Rhodotorula mucilaginosa) the general pattern was for the sn-2 position to be occupied by 18:1, 18:2 or linolenic acid 18:3. A trend towards synthesis of increased unsaturated fatty acid in TAGs was observed as the growth temperature was lowered. The application of principal component analysis demonstrated that the yeasts were differentiated into three distinct groups. One group consisted of the three S. cerevisiae strains, a second the other four non-Antarctic yeasts and the third the seven Antarctic yeasts. The data for the Antarctic yeasts, to the best of our knowledge, have not been previously reported. PMID:23831436

  13. Rapid Differentiation of Aspergillus Species from Other Medically Important Opportunistic Molds and Yeasts by PCR-Enzyme Immunoassay

    PubMed Central

    de Aguirre, Liliana; Hurst, Steven F.; Choi, Jong Soo; Shin, Jong Hee; Hinrikson, Hans Peter; Morrison, Christine J.

    2004-01-01

    We developed a PCR-based assay to differentiate medically important species of Aspergillus from one another and from other opportunistic molds and yeasts by employing universal, fungus-specific primers and DNA probes in an enzyme immunoassay format (PCR-EIA). Oligonucleotide probes, directed to the internal transcribed spacer 2 region of ribosomal DNA from Aspergillus flavus, Aspergillus fumigatus, Aspergillus nidulans, Aspergillus niger, Aspergillus terreus, Aspergillus ustus, and Aspergillus versicolor, differentiated 41 isolates (3 to 9 each of the respective species; P < 0.001) in a PCR-EIA detection matrix and gave no false-positive reactions with 33 species of Acremonium, Exophiala, Candida, Fusarium, Mucor, Paecilomyces, Penicillium, Rhizopus, Scedosporium, Sporothrix, or other aspergilli tested. A single DNA probe to detect all seven of the most medically important Aspergillus species (A. flavus, A. fumigatus, A. nidulans, A. niger, A. terreus, A. ustus, and A. versicolor) was also designed. Identification of Aspergillus species was accomplished within a single day by the PCR-EIA, and as little as 0.5 pg of fungal DNA could be detected by this system. In addition, fungal DNA extracted from tissues of experimentally infected rabbits was successfully amplified and identified using the PCR-EIA system. This method is simple, rapid, and sensitive for the identification of medically important Aspergillus species and for their differentiation from other opportunistic fungi. PMID:15297489

  14. Use of the VITEK 2 system to identify and test the antifungal susceptibility of clinically relevant yeast species.

    PubMed

    Melhem, M S C; Bertoletti, A; Lucca, H R L; Silva, R B O; Meneghin, F A; Szeszs, M W

    2013-12-01

    Eleven quality control isolates (Candida albicans ATCC 64548, C. tropicalis ATCC 200956, C. glabrata ATCC 90030, C. lusitaniae ATCC 200951, C. parapsilosis ATCC 22019, C. krusei ATCC 6258, C. dubliniensis ATCC 6330, Saccharomyces cerevisiae ATCC 9763, Cryptococcus neoformans ATCC 90012, C. gattii FIOCRUZ-CPF 60, and Trichosporon mucoides ATCC 204094) and 32 bloodstream isolates, including C. albicans, C. tropicalis, C. parapsilosis, C. glabrata, C. krusei, C. guilliermondii, C. pelliculosa (Pichia anomala), C. haemulonii, C. lusitaniae, and C. kefyr were identified at the species level by the VITEK 2 system. A set of clinical isolates (32 total) were used as challenge strains to evaluate the ability of the VITEK 2 system to determine the antifungal susceptibility of yeasts compared with the CLSI and EUCAST BMD reference standards. The VITEK 2 system correctly identified 100% of the challenge strains. The identification of yeast species and the evaluation of their susceptibility profiles were performed in an automated manner by the VITEK 2 system after approximately 15 h of growth for most species of Candida. The VITEK 2 system ensures that each test is performed in a standardized manner and provides quantitative MIC results that are reproducible and accurate when compared with the BMD reference methods. This system was able to determine the MICs of amphotericin B, flucytosine, voriconazole, and fluconazole in 15 h or less for the most common clinically relevant Candida species. In addition, the VITEK 2 system could reliably identify resistance to flucytosine, voriconazole, and fluconazole and exhibits excellent quantitative and qualitative agreement with the CLSI or EUCAST broth microdilution reference methods. PMID:24688520

  15. Use of the VITEK 2 system to identify and test the antifungal susceptibility of clinically relevant yeast species

    PubMed Central

    Melhem, MSC; Bertoletti, A; Lucca, HRL; Silva, RBO; Meneghin, FA; Szeszs, MW

    2013-01-01

    Eleven quality control isolates (Candida albicans ATCC 64548, C. tropicalis ATCC 200956, C. glabrata ATCC 90030, C. lusitaniae ATCC 200951, C. parapsilosis ATCC 22019, C. krusei ATCC 6258, C. dubliniensis ATCC 6330, Saccharomyces cerevisiae ATCC 9763, Cryptococcus neoformans ATCC 90012, C. gattii FIOCRUZ-CPF 60, and Trichosporon mucoides ATCC 204094) and 32 bloodstream isolates, including C. albicans, C. tropicalis, C. parapsilosis, C. glabrata, C. krusei, C. guilliermondii, C. pelliculosa (Pichia anomala), C. haemulonii, C. lusitaniae, and C. kefyr were identified at the species level by the VITEK 2 system. A set of clinical isolates (32 total) were used as challenge strains to evaluate the ability of the VITEK 2 system to determine the antifungal susceptibility of yeasts compared with the CLSI and EUCAST BMD reference standards. The VITEK 2 system correctly identified 100% of the challenge strains. The identification of yeast species and the evaluation of their susceptibility profiles were performed in an automated manner by the VITEK 2 system after approximately 15 h of growth for most species of Candida. The VITEK 2 system ensures that each test is performed in a standardized manner and provides quantitative MIC results that are reproducible and accurate when compared with the BMD reference methods. This system was able to determine the MICs of amphotericin B, flucytosine, voriconazole, and fluconazole in 15 h or less for the most common clinically relevant Candida species. In addition, the VITEK 2 system could reliably identify resistance to flucytosine, voriconazole, and fluconazole and exhibits excellent quantitative and qualitative agreement with the CLSI or EUCAST broth microdilution reference methods. PMID:24688520

  16. Morphological and physiological features of Arthroderma benhamiae anamorphs isolated in northern Germany.

    PubMed

    Brasch, Jochen; Wodarg, Svea

    2015-02-01

    The anamorph of Arthroderma benhamiae is an upcoming zoophilic dermatophyte that only in recent years has gained importance as a cause of tinea in humans. Its identification by conventional methods can cause problems. In this study we have subjected seven genetically confirmed strains of A. benhamiae anamorphs from northern Germany recently identified in our laboratory to a comprehensive assessment. Their macroscopic and microscopic morphology was checked on various agars and enzyme release stimulated by substrates with keratin, hair perforation and other physiological characteristics were tested. All strains were related to the previously described yellow phenotype of the A. benhamiae anamorph and showed a high resemblance among themselves. Coherent features were their uniform thallus morphology on Sabouraud glucose agar with yellow pigmentation, the formation of circuit-like hyphal structures and hyphal connections that had not been described previously, a lack of conidia, thiamine dependence, the spectrum of released enzymes and a good growth on human stratum corneum. With exception of the latter two these criteria are suggested for the identification of this anamorph phenotype that should be evaluated by future observations. Different phenotypes of the A. benhamiae anamorph may prevail in other geographic regions. PMID:25530423

  17. Deep fungal dermatitis caused by the Chrysosporium anamorph of Nannizziopsis vriesii in captive coastal bearded dragons (Pogona barbata).

    PubMed

    Johnson, R S P; Sangster, C R; Sigler, L; Hambleton, S; Paré, J A

    2011-12-01

    Deep fungal dermatitis caused by the Chrysosporium anamorph of Nannizziopsis vriesii (CANV) was diagnosed in a group of coastal bearded dragons (Pogona barbata). The outbreak extended over a 6-month period, with four of six lizards from the same zoological outdoor enclosure succumbing to infection. A fifth case of dermatomycosis was identified in a pet lizard originally sourced from the wild. Diagnosis of infection with the CANV was based on similar clinical signs and histopathology in all animals and confirmed by culture and sequencing of the fungus from one animal. This is the first report of the CANV causing disease in a terrestrial reptile species in Australia and the first in the coastal bearded dragon. PMID:22103953

  18. AFLP fingerprinting for identification of infra-species groups of Rhizoctonia solani and Waitea circinata

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Patch diseases caused by Thanatephorus cucumeris and Waitea circinata varieties (anamorphs: Rhizoctonia species) pose a serious threat to successful maintenance of several important turfgrass species. Reliance on field symptoms to identify Rhizoctonia causal agents can be difficult and misleading. D...

  19. Enhanced Longevity by Ibuprofen, Conserved in Multiple Species, Occurs in Yeast through Inhibition of Tryptophan Import

    PubMed Central

    He, Chong; Tsuchiyama, Scott K.; Nguyen, Quynh T.; Plyusnina, Ekaterina N.; Terrill, Samuel R.; Sahibzada, Sarah; Patel, Bhumil; Faulkner, Alena R.; Shaposhnikov, Mikhail V.; Tian, Ruilin; Tsuchiya, Mitsuhiro; Kaeberlein, Matt; Moskalev, Alexey A.; Kennedy, Brian K.; Polymenis, Michael

    2014-01-01

    The common non-steroidal anti-inflammatory drug ibuprofen has been associated with a reduced risk of some age-related pathologies. However, a general pro-longevity role for ibuprofen and its mechanistic basis remains unclear. Here we show that ibuprofen increased the lifespan of Saccharomyces cerevisiae, Caenorhabditis elegans and Drosophila melanogaster, indicative of conserved eukaryotic longevity effects. Studies in yeast indicate that ibuprofen destabilizes the Tat2p permease and inhibits tryptophan uptake. Loss of Tat2p increased replicative lifespan (RLS), but ibuprofen did not increase RLS when Tat2p was stabilized or in an already long-lived strain background impaired for aromatic amino acid uptake. Concomitant with lifespan extension, ibuprofen moderately reduced cell size at birth, leading to a delay in the G1 phase of the cell cycle. Similar changes in cell cycle progression were evident in a large dataset of replicatively long-lived yeast deletion strains. These results point to fundamental cell cycle signatures linked with longevity, implicate aromatic amino acid import in aging and identify a largely safe drug that extends lifespan across different kingdoms of life. PMID:25521617

  20. Yeast diversity in a traditional French cheese "Tomme d'orchies" reveals infrequent and frequent species with associated benefits.

    PubMed

    Ceugniez, Alexandre; Drider, Djamel; Jacques, Philippe; Coucheney, Françoise

    2015-12-01

    This study is aimed at unrevealing the yeast diversity of handmade cheese, Tomme d'orchies, produced and marketed in the north of France. A total of 185 yeast colonies were isolated from the surface and core of this cheese. From these, 80 morphologically different colonies were selected and subjected to rep-PCR analysis. The isolates were clustered into six distinct groups based on their DNA fingerprints. From each group, at least 30% of isolates were selected and identified to species level by biochemical characteristics (ID32C Api system) and sequencing of the ITS1-5.8S-ITS2 and 26S rDNA regions. The isolates belonged to Yarrowia lipolytica, Debaryomyces hansenii, Kluyveromyces lactis and Kluyveromyces marxianus, frequently isolated, and less frequently isolated Saturnispora mendoncae and Clavispora lusitaniae. Two isolates designated as Kluyveromyces lactis (isolate S-3-05) and Kluyveromyces marxianus (isolate S-2-05) were non-hemolytic, sensitive to antifungal compounds and able to inhibit the growth of pathogens including Candida albicans, Listeria monocytogenes and some bacilli. PMID:26338133

  1. Yeasts isolated from Algerian infants's feces revealed a burden of Candida albicans species, non-albicans Candida species and Saccharomyces cerevisiae.

    PubMed

    Seddik, Hamza Ait; Ceugniez, Alexandre; Bendali, Farida; Cudennec, Benoit; Drider, Djamel

    2016-01-01

    This study aimed at showing the yeast diversity in feces of Algerian infants, aged between 1 and 24 months, hospitalized at Bejaia hospital (northeast side of the country). Thus, 20 colonies with yeast characteristics were isolated and identified using biochemical (ID32C Api system) and molecular (sequencing of ITS1-5.8S-ITS2 region) methods. Almost all colonies isolated (19 strains) were identified as Candida spp., with predominance of Candida albicans species, and one strain was identified as Saccharomyces cerevisiae. Screening of strains with inhibitory activities unveiled the potential of Candida parapsilosis P48L1 and Candida albicans P51L1 to inhibit the growth of Escherichia coli ATCC 25922 and Staphylococcus aureus ATCC 25923. Further studies performed with these two Candida strains revealed their susceptibility to clinically used antifungal compounds and were then characterized for their cytotoxicity and hemolytic properties. On the other hand, Saccharomyces cerevisiae P9L1 isolated as well in this study was shown to be devoid of antagonism but resulted safe and overall usable as probiotic. PMID:26404657

  2. ChIPseq in Yeast Species: From Chromatin Immunoprecipitation to High-Throughput Sequencing and Bioinformatics Data Analyses.

    PubMed

    Lelandais, Gaëlle; Blugeon, Corinne; Merhej, Jawad

    2016-01-01

    Chromatin immunoprecipitation (ChIP) followed by high-throughput sequencing (ChIPseq) is a powerful technique for the genome-wide location of protein DNA-binding sites. The ChIP experiment consists in treating living cells with a cross-linking agent to bind proteins to their DNA substrates. After fragmentation of DNA, specific fractions associated with a particular protein of interest are purified by immunoaffinity. They are next sequenced and identified on the reference genome using dedicated bioinformatics programs. Several technical aspects are important to obtain high-quality ChIPseq results. This includes the quality of antibodies, the sequencing protocols, the use of accurate controls and the careful choice of bioinformatics tools. We present here a general protocol to perform ChIPseq analyses in yeast species. This protocol has been optimized to identify target genes of specific transcription factors but can be used for any other DNA binding proteins. PMID:26483023

  3. Direct identification and recognition of yeast species from clinical material by using albicans ID and CHROMagar Candida plates.

    PubMed Central

    Baumgartner, C; Freydiere, A M; Gille, Y

    1996-01-01

    Two chromogenic media, Albicans ID and CHROMagar Candida agar plates, were compared with a reference medium, Sabouraud-chloramphenicol agar, and standard methods for the identification of yeast species. This study involved 951 clinical specimens. The detection rates for the two chromogenic media for polymicrobial specimens were 20% higher than that for the Sabouraud-chloramphenicol agar plates. The rates of identification of Candida albicans for Albicans ID and CHROMagar Candida agar plates were, respectively, 37.0 and 6.0% after 24 h of incubation and 93.6 and 92.2% after 72 h of incubation, with specificities of 99.8 and 100%. Furthermore, CHROMagar Candida plates identified 13 of 14 Candida tropicalis and 9 of 12 Candida krusei strains after 48 h of incubation. PMID:8789038

  4. Phylogeny of tremellomycetous yeasts and related dimorphic and filamentous basidiomycetes reconstructed from multiple gene sequence analyses

    PubMed Central

    Liu, X.-Z.; Wang, Q.-M.; Theelen, B.; Groenewald, M.; Bai, F.-Y.; Boekhout, T.

    2015-01-01

    The Tremellomycetes (Basidiomycota) contains a large number of unicellular and dimorphic fungi with stable free-living unicellular states in their life cycles. These fungi have been conventionally classified as basidiomycetous yeasts based on physiological and biochemical characteristics. Many currently recognised genera of these yeasts are mainly defined based on phenotypical characters and are highly polyphyletic. Here we reconstructed the phylogeny of the majority of described anamorphic and teleomorphic tremellomycetous yeasts using Bayesian inference, maximum likelihood, and neighbour-joining analyses based on the sequences of seven genes, including three rRNA genes, namely the small subunit of the ribosomal DNA (rDNA), D1/D2 domains of the large subunit rDNA, and the internal transcribed spacer regions (ITS 1 and 2) of rDNA including 5.8S rDNA; and four protein-coding genes, namely the two subunits of the RNA polymerase II (RPB1 and RPB2), the translation elongation factor 1-α (TEF1) and the mitochondrial gene cytochrome b (CYTB). With the consideration of morphological, physiological and chemotaxonomic characters and the congruence of phylogenies inferred from analyses using different algorithms based on different data sets consisting of the combined seven genes, the three rRNA genes, and the individual protein-coding genes, five major lineages corresponding to the orders Cystofilobasidiales, Filobasidiales, Holtermanniales, Tremellales, and Trichosporonales were resolved. A total of 45 strongly supported monophyletic clades with multiple species and 23 single species clades were recognised. This phylogenetic framework will be the basis for the proposal of an updated taxonomic system of tremellomycetous yeasts that will be compatible with the current taxonomic system of filamentous basidiomycetes accommodating the ‘one fungus, one name’ principle. PMID:26955196

  5. The Interaction between Saccharomyces cerevisiae and Non-Saccharomyces Yeast during Alcoholic Fermentation Is Species and Strain Specific.

    PubMed

    Wang, Chunxiao; Mas, Albert; Esteve-Zarzoso, Braulio

    2016-01-01

    The present study analyzes the lack of culturability of different non-Saccharomyces strains due to interaction with Saccharomyces cerevisiae during alcoholic fermentation. Interaction was followed in mixed fermentations with 1:1 inoculation of S. cerevisiae and ten non-Saccharomyces strains. Starmerella bacillaris, and Torulaspora delbrueckii indicated longer coexistence in mixed fermentations compared with Hanseniaspora uvarum and Metschnikowia pulcherrima. Strain differences in culturability and nutrient consumption (glucose, alanine, ammonium, arginine, or glutamine) were found within each species in mixed fermentation with S. cerevisiae. The interaction was further analyzed using cell-free supernatant from S. cerevisiae and synthetic media mimicking both single fermentations with S. cerevisiae and using mixed fermentations with the corresponding non-Saccharomyces species. Cell-free S. cerevisiae supernatants induced faster culturability loss than synthetic media corresponding to the same fermentation stage. This demonstrated that some metabolites produced by S. cerevisiae played the main role in the decreased culturability of the other non-Saccharomyces yeasts. However, changes in the concentrations of main metabolites had also an effect. Culturability differences were observed among species and strains in culture assays and thus showed distinct tolerance to S. cerevisiae metabolites and fermentation environment. Viability kit and recovery analyses on non-culturable cells verified the existence of viable but not-culturable status. These findings are discussed in the context of interaction between non-Saccharomyces and S. cerevisiae. PMID:27148191

  6. The Interaction between Saccharomyces cerevisiae and Non-Saccharomyces Yeast during Alcoholic Fermentation Is Species and Strain Specific

    PubMed Central

    Wang, Chunxiao; Mas, Albert; Esteve-Zarzoso, Braulio

    2016-01-01

    The present study analyzes the lack of culturability of different non-Saccharomyces strains due to interaction with Saccharomyces cerevisiae during alcoholic fermentation. Interaction was followed in mixed fermentations with 1:1 inoculation of S. cerevisiae and ten non-Saccharomyces strains. Starmerella bacillaris, and Torulaspora delbrueckii indicated longer coexistence in mixed fermentations compared with Hanseniaspora uvarum and Metschnikowia pulcherrima. Strain differences in culturability and nutrient consumption (glucose, alanine, ammonium, arginine, or glutamine) were found within each species in mixed fermentation with S. cerevisiae. The interaction was further analyzed using cell-free supernatant from S. cerevisiae and synthetic media mimicking both single fermentations with S. cerevisiae and using mixed fermentations with the corresponding non-Saccharomyces species. Cell-free S. cerevisiae supernatants induced faster culturability loss than synthetic media corresponding to the same fermentation stage. This demonstrated that some metabolites produced by S. cerevisiae played the main role in the decreased culturability of the other non-Saccharomyces yeasts. However, changes in the concentrations of main metabolites had also an effect. Culturability differences were observed among species and strains in culture assays and thus showed distinct tolerance to S. cerevisiae metabolites and fermentation environment. Viability kit and recovery analyses on non-culturable cells verified the existence of viable but not-culturable status. These findings are discussed in the context of interaction between non-Saccharomyces and S. cerevisiae. PMID:27148191

  7. Pseudozyma brasiliensis sp. nov., a xylanolytic, ustilaginomycetous yeast species isolated from an insect pest of sugarcane roots.

    PubMed

    Oliveira, Juliana Velasco de Castro; Borges, Thuanny A; Corrêa dos Santos, Renato Augusto; Freitas, Larissa F D; Rosa, Carlos Augusto; Goldman, Gustavo Henrique; Riaño-Pachón, Diego Mauricio

    2014-06-01

    A novel ustilaginomycetous yeast isolated from the intestinal tract of an insect pest of sugarcane roots in Ribeirão Preto, São Paulo State, Brazil, represents a novel species of the genus Pseudozyma based on molecular analyses of the D1/D2 rDNA large subunit and the internal transcribed spacer (ITS1+ITS2) regions. The name Pseudozyma brasiliensis sp. nov. is proposed for this species, with GHG001(T) ( = CBS 13268(T) = UFMG-CM-Y307(T)) as the type strain. P. brasiliensis sp. nov. is a sister species of Pseudozyma vetiver, originally isolated from leaves of vetiver grass and sugarcane in Thailand. P. brasiliensis sp. nov. is able to grow well with xylan as the sole carbon source and produces high levels of an endo-1,4-xylanase that has a higher specific activity in comparison with other eukaryotic xylanases. This enzyme has a variety of industrial applications, indicating the great biotechnological potential of P. brasiliensis. PMID:24682702

  8. Wickerhamiella siamensis f.a., sp. nov., an endophytic and epiphytic yeast species isolated from sugar cane leaf.

    PubMed

    Khunnamwong, Pannida; Surussawadee, Janjira; Jindamorakot, Sasitorn; Limtong, Savitree

    2014-11-01

    Six strains representing a novel yeast species were isolated from tissue (DMKU-SE106(T), DMKU-SE110, DMKU-SE112 and DMKU-SE132) and the external surface (DMKU-SP335 and DMKU-SP406) of sugar cane leaves collected in Thailand. On the basis of morphological, biochemical, physiological and chemotaxonomic characteristics, and sequence analysis of the D1/D2 region of the LSU rRNA gene and the internal transcribed spacer (ITS) region, the six strains were found to represent a single novel species of the genus Wickerhamiella although the formation of ascospores was not observed. The sequences of the D1/D2 region of the LSU rRNA gene and ITS region of the six strains differed from each other by 0-2 and 2-3 nt substitutions, respectively. The novel species was related most closely to Candida infanticola but with 4.5-4.6% nucleotide substitutions in the D1/D2 region of the LSU rRNA gene and 6.6-7.1% nucleotide substitutions in the ITS region. The name Wickerhamiella siamensis f.a., sp. nov. is proposed. The type strain is DMKU-SE106(T) ( =BCC 61185(T) =NBRC 109697(T) =CBS 13331(T)). PMID:25168613

  9. Kazachstania yasuniensis sp. nov., an ascomycetous yeast species found in mainland Ecuador and on the Galápagos.

    PubMed

    James, Stephen A; Carvajal Barriga, Enrique Javier; Portero Barahona, Patricia; Nueno-Palop, Carmen; Cross, Kathryn; Bond, Christopher J; Roberts, Ian N

    2015-04-01

    Seven strains representing a novel yeast species belonging to the genus Kazachstania were found at several collection sites on both mainland Ecuador (Yasuní National Park) and the Galápagos (Santa Cruz Island). Two strains (CLQCA 20-132(T) and CLQCA 24SC-045) were isolated from rotten wood samples, two further strains (CLQCA 20-280 and CLQCA 20-348) were isolated from soil samples, and three strains (CLQCA 20-198, CLQCA 20-374 and CLQCA 20-431) were isolated from decaying fruits. Sequence analyses of the D1/D2 domains of the LSU rRNA gene and ribosomal internal transcribed spacer (ITS) region indicated that the novel species is most closely related to Kazachstania servazzii and Kazachstania unispora. Although the strains could not be distinguished from one another based upon their differing geographical origins, they could be differentiated according to their isolation source (fruit, soil or wood) by ITS sequencing. The species name Kazachstania yasuniensis sp. nov. is proposed to accommodate these strains, with CLQCA 20-132(T) ( = CBS 13946(T) = NCYC 4008(T)) designated the type strain. PMID:25644482

  10. Candida baotianmanensis sp. nov. and Candida pseudoviswanathii sp. nov., two ascosporic yeast species isolated from the gut of beetles.

    PubMed

    Ren, Yong-Cheng; Xu, Long-Long; Zhang, Lin; Hui, Feng-Li

    2015-10-01

    Four yeast strains were isolated from the gut of beetles collected on Baotianman Mountain and People's Park of Nanyang in Henan Province, China. These strains produced unconjugated asci with one or two ellipsoidal to elongate ascospores in a persistent ascus. Phylogenetic analysis of the D1/D2 domains of the LSU rRNA gene sequences indicated that the isolates represent two novel sexual species in the Candida/Lodderomyces clade. Candida baotianmanensis sp. nov. was located in a statistically well-supported branch together with Candida maltosa. Candida pseudoviswanathii sp. nov. formed a subclade with its closest relative Candida viswanathii supported by a strong bootstrap value. The two novel species were distinguished from their most closely related described species, Candida maltosa and Candida viswanathii, in the D1/D2 LSU rRNA gene and internal transcribed spacer (ITS) sequences and in phenotypic traits. The type strain of Candida baotianmanensis sp. nov. is NYNU 14719T ( = CBS 13915T = CICC 33052T), and the type strain of Candida pseudoviswanathii sp. nov. is NYNU 14772T ( = CBS 13916T = CICC 33053T). The MycoBank numbers for Candida baotianmanensis sp. nov. and Candida pseudoviswanathii sp. nov. are MB 812621 and MB 812622. PMID:26297152

  11. Yamadazyma ubonensis f.a., sp. nov., a novel xylitol-producing yeast species isolated in Thailand.

    PubMed

    Junyapate, Keeratichaiyanan; Jindamorakot, Sasitorn; Limtong, Savitree

    2014-03-01

    Three hundred and thirty-seven xylose-utilizing yeast strains were isolated from various natural samples. Among these, 68 strains produced xylitol in the range of 0.1-0.69 g xylitol/g xylose. Thirty-nine xylitol-producing strains were identified to be Candida tropicalis. Ten strains were found belonging to 14 known species in the genus Candida, Cyberlindnera, Meyerozyma, Pichia, Wickerhamomyces, Yamadazyma and Cryptococcus. Two strains were identified to be two Candida species and two strains (DMKU-XE142(T) and DMKU-XE332) were found to be a novel species. Strain DMKU-XE142(T) was isolated from tree bark and DMKU-XE332 was obtained from decaying plant leaf collected in Thailand. On the basis of morphological, biochemical, physiological and chemotaxonomic characteristics and sequence analysis of the D1/D2 region of the large subunit rRNA gene (LSU) and the internal transcribed spacer (ITS) region, the two strains were determined to represent a novel Yamadazyma species although formation of ascospores was not observed. The sequences of the D1/D2 region of the LSU rRNA gene and the ITS region of the two strains were identical but differed from Yamadazyma phyllophila, the closest species in terms of pairwise sequence similarity of the D1/D2 region, by 1.7 % nucleotide substitutions and 3.5 % nucleotide substitutions in the ITS region. The name Yamadazyma ubonensis f.a., sp. nov. is proposed (type strain is DMKU-XE142(T) = BCC 61020(T) = CBS 12859(T)). PMID:24346846

  12. Pichia dushanensis sp. nov. and Hyphopichia paragotoi sp. nov., two sexual yeast species associated with insects and rotten wood.

    PubMed

    Ren, Yong-Cheng; Liu, Si-Tong; Li, Ying; Hui, Feng-Li

    2015-09-01

    Seven yeast strains were isolated from the gut of insect larvae and decayed wood, which were collected from three localities near Nanyang, Henan Province, China. These strains were identified as two novel species through comparison of sequences in the D1/D2 domains of the large subunit (LSU) rRNA gene and other taxonomic characteristics. Pichia dushanensis sp. nov. was closely related to species in the Pichia clade and produced one to four spheroid ascospores in a deliquescent ascus. The D1/D2 sequence of P. dushanensis sp. nov. differed from its closest relative, Issatchenkia (Pichia) sp. NRRL Y-12824, by 3.6% sequence divergence (16 substitutions and 4 gaps). The species also differed from its four closest known species, Candida rugopelliculosa, Pichia occidentalis, Pichia exigua and Candida phayaonensis, by 4.1-4.4% sequence divergence (22-24 substitutions and 0-2 gaps) in the D1/D2 sequences. Hyphopichia paragotoi sp. nov. belonged to the Hyphopichia clade, and its nearest phylogenetic neighbours were Candida gotoi, Candida pseudorhagii, Candida rhagii and Hyphopichia heimii with 3.2-4.2% sequence divergence (16-21 substitutions and 1 gap) in the D1/D2 sequences. In comparison with previously established species, H. paragotoi sp. nov. formed one hat-shaped ascospore in a persistent ascus. The type strain of P. dushanensis sp. nov. is NYNU 14658(T) ( = CICC 33049(T) = CBS 13912(T)), and the type strain of H. paragotoi sp. nov. is NYNU 14666(T) ( = CICC 33048(T) = CBS 13913(T)). PMID:25999593

  13. Calcium and reactive oxygen species in regulation of the mitochondrial permeability transition and of programmed cell death in yeast.

    PubMed

    Carraro, Michela; Bernardi, Paolo

    2016-08-01

    Mitochondria-dependent programmed cell death (PCD) in yeast shares many features with the intrinsic apoptotic pathway of mammals. With many stimuli, increased cytosolic [Ca(2+)] and ROS generation are the triggering signals that lead to mitochondrial permeabilization and release of proapoptotic factors, which initiates yeast PCD. While in mammals the permeability transition pore (PTP), a high-conductance inner membrane channel activated by increased matrix Ca(2+) and oxidative stress, is recognized as part of this signaling cascade, whether a similar process occurs in yeast is still debated. The potential role of the PTP in yeast PCD has generally been overlooked because yeast mitochondria lack the Ca(2+) uniporter, which in mammals allows rapid equilibration of cytosolic Ca(2+) with the matrix. In this short review we discuss the nature of the yeast permeability transition and reevaluate its potential role in the effector phase of yeast PCD triggered by Ca(2+) and oxidative stress. PMID:26995056

  14. An Effective Big Data Supervised Imbalanced Classification Approach for Ortholog Detection in Related Yeast Species.

    PubMed

    Galpert, Deborah; Del Río, Sara; Herrera, Francisco; Ancede-Gallardo, Evys; Antunes, Agostinho; Agüero-Chapin, Guillermin

    2015-01-01

    Orthology detection requires more effective scaling algorithms. In this paper, a set of gene pair features based on similarity measures (alignment scores, sequence length, gene membership to conserved regions, and physicochemical profiles) are combined in a supervised pairwise ortholog detection approach to improve effectiveness considering low ortholog ratios in relation to the possible pairwise comparison between two genomes. In this scenario, big data supervised classifiers managing imbalance between ortholog and nonortholog pair classes allow for an effective scaling solution built from two genomes and extended to other genome pairs. The supervised approach was compared with RBH, RSD, and OMA algorithms by using the following yeast genome pairs: Saccharomyces cerevisiae-Kluyveromyces lactis, Saccharomyces cerevisiae-Candida glabrata, and Saccharomyces cerevisiae-Schizosaccharomyces pombe as benchmark datasets. Because of the large amount of imbalanced data, the building and testing of the supervised model were only possible by using big data supervised classifiers managing imbalance. Evaluation metrics taking low ortholog ratios into account were applied. From the effectiveness perspective, MapReduce Random Oversampling combined with Spark SVM outperformed RBH, RSD, and OMA, probably because of the consideration of gene pair features beyond alignment similarities combined with the advances in big data supervised classification. PMID:26605337

  15. An Effective Big Data Supervised Imbalanced Classification Approach for Ortholog Detection in Related Yeast Species

    PubMed Central

    Galpert, Deborah; del Río, Sara; Herrera, Francisco; Ancede-Gallardo, Evys; Antunes, Agostinho; Agüero-Chapin, Guillermin

    2015-01-01

    Orthology detection requires more effective scaling algorithms. In this paper, a set of gene pair features based on similarity measures (alignment scores, sequence length, gene membership to conserved regions, and physicochemical profiles) are combined in a supervised pairwise ortholog detection approach to improve effectiveness considering low ortholog ratios in relation to the possible pairwise comparison between two genomes. In this scenario, big data supervised classifiers managing imbalance between ortholog and nonortholog pair classes allow for an effective scaling solution built from two genomes and extended to other genome pairs. The supervised approach was compared with RBH, RSD, and OMA algorithms by using the following yeast genome pairs: Saccharomyces cerevisiae-Kluyveromyces lactis, Saccharomyces cerevisiae-Candida glabrata, and Saccharomyces cerevisiae-Schizosaccharomyces pombe as benchmark datasets. Because of the large amount of imbalanced data, the building and testing of the supervised model were only possible by using big data supervised classifiers managing imbalance. Evaluation metrics taking low ortholog ratios into account were applied. From the effectiveness perspective, MapReduce Random Oversampling combined with Spark SVM outperformed RBH, RSD, and OMA, probably because of the consideration of gene pair features beyond alignment similarities combined with the advances in big data supervised classification. PMID:26605337

  16. Shared Physiological Traits of Exophiala Species in Cold-Blooded Vertebrates, as Opportunistic Black Yeasts.

    PubMed

    do Nascimento, Mariana Machado Fidelis; de Hoog, G Sybren; Gomes, Renata Rodrigues; Furuie, Jason Lee; Gelinski, Jane Mary Lafayette; Najafzadeh, Mohammad Javad; Boeger, Walter Antonio Pereira; Vicente, Vania Aparecida

    2016-06-01

    Several species of the genus Exophiala are found as opportunistic pathogens on humans, while others cause infections in cold-blooded waterborne vertebrates. Opportunism of these fungi thus is likely to be multifactorial. Ecological traits [thermotolerance and pH tolerance, laccase activity, assimilation of mineral oil, and decolorization of Remazol Brilliant Blue R (RBBR)] were studied in a set of 40 strains of mesophilic Exophiala species focused on the salmonis-clade mainly containing waterborne species. Thermophilic species and waterborne species outside the salmonis-clade were included for comparison. Strains were able to tolerate a wide range of pHs, although optimal growth was observed between pH 4.0 and 5.5. All strains tested were laccase positive. Strains were able to grow in the presence of the compounds (mineral oil and RBBR) with some differences in assimilation patterns between strains tested and also were capable of degrading the main chromophore of RBBR. The study revealed that distantly related mesophilic species behave similarly, and no particular trend in evolutionary adaptation was observed. PMID:27028446

  17. Genomics and the making of yeast biodiversity

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Yeasts are unicellular fungi that do not form fruiting bodies. Although the yeast lifestyle has evolved multiple times, most known species belong to the subphylum Saccharomycotina (syn. Hemiascomycota, hereafter yeasts). This diverse group includes the premier eukaryotic model system, Saccharomyces ...

  18. Cyanonectria, a new genus for “Nectria” cyanostoma and its Fusarium anamorph

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The new genus Cyanonectria is proposed for Nectria cyanostoma (= Cyanonectria cyanostoma comb. nov.). This genus is characterized by Nectria-like, red perithecia that have a bluish-purple papilla and a Fusarium anamorph. DNA sequences (large subunit and internal transcribed spacers of the nuclear rD...

  19. The Visual Journal as an Image Sphere: Interpreting Artworks with an Anamorphic Perspective

    ERIC Educational Resources Information Center

    Sinner, Anita

    2011-01-01

    During a 1-year study, the visual journal of a preservice teacher was explored as an image sphere, or "bildraum", in relation to teacher culture. Artworks created in the visual journal offered an anamorphic perspective on the materiality of teacher culture, tracing the lived experiences of a student of art in the process of becoming an art teacher…

  20. Importance of low-oligomeric-weight species for prion propagation in the yeast prion system Sup35/Hsp104

    PubMed Central

    Narayanan, Saravanakumar; Bösl, Benjamin; Walter, Stefan; Reif, Bernd

    2003-01-01

    The [PSI+] determinant of Saccharomyces cerevisiae, consisting of the cytosolic translation termination factor Sup35, is a prion-type genetic element that induces an inheritable conformational change and converts the Sup35 protein into amyloid fibers. The molecular chaperone Hsp104 is required to maintain self-replication of [PSI+]. We observe in vitro that addition of catalytic amounts of Hsp104 to the prion-determining region of the NM domain of Sup35, Sup355–26, results in the dissociation of oligomeric Sup35 into monomeric species. Several intermediates of Sup355–26 could be detected during this process. Strong interactions are found between Hsp104 and hexameric/tetrameric Sup355–26, whereas the intermediate and monomeric “release” forms show a decreased affinity with respect to Hsp104, as monitored by saturation transfer difference and diffusion-ordered NMR spectroscopic experiments. Interactions are mediated mostly by the side chains of Gln, Asn, and Tyr residues in Sup355–26. No interaction can be detected between Hsp104 and higher oligomeric states (≥8) of Sup355–26. Taking into account the fact that Hsp104 is required for maintenance of [PSI+], we suggest that low-oligomeric-weight species of Sup35 are important for prion propagation in yeast. PMID:12876196

  1. Starmerella meliponinorum sp. nov., a novel ascomycetous yeast species associated with stingless bees.

    PubMed

    Teixeira, Ana C P; Marini, Marjorie M; Nicoli, Jacques R; Antonini, Yasmine; Martins, Rogerio P; Lachance, Marc-André; Rosa, Carlos A

    2003-01-01

    Thirty-two strains of the novel species Starmerella meliponinorum sp. nov. were isolated from various substrates associated with three stingless bee species (tribe Meliponini) in Brazil and one in Costa Rica. The strains were found in garbage pellets (faecal material, discarded pollen or food, etc.), pollen provisions, adult bees, honey and propolis of Tetragonisca angustula, in honey from Melipona quadritasciata and in adults of Melipona rufiventris and Trigona fulviventris. The sequence of the D1/D2 domains of the large-subunit rDNA showed that the novel species belongs to the Starmerella clade and is most closely related to Candida etchellsii, although the two differ in their sequences by 7% base substitutions. S. meliponinorum is homothallic and assimilates few carbon sources. Nitrate is utilized as a sole nitrogen source. The type strain of S. meliponinorum is strain UFMG-01-J26.1T (=CBS 9117T). PMID:12656193

  2. Identification of Medically Relevant Species of Arthroconidial Yeasts by Use of Matrix-Assisted Laser Desorption Ionization–Time of Flight Mass Spectrometry

    PubMed Central

    Kolecka, Anna; Khayhan, Kantarawee; Groenewald, Marizeth; Theelen, Bart; Arabatzis, Michael; Velegraki, Aristea; Kostrzewa, Markus; Mares, Mihai; Taj-Aldeen, Saad J.

    2013-01-01

    Matrix-assisted laser desorption ionization–time of flight mass spectrometry (MALDI-TOF MS) was used for an extensive identification study of arthroconidial yeasts, using 85 reference strains from the CBS-KNAW yeast collection and 134 clinical isolates collected from medical centers in Qatar, Greece, and Romania. The test set included 72 strains of ascomycetous yeasts (Galactomyces, Geotrichum, Saprochaete, and Magnusiomyces spp.) and 147 strains of basidiomycetous yeasts (Trichosporon and Guehomyces spp.). With minimal preparation time, MALDI-TOF MS proved to be an excellent diagnostic tool that provided reliable identification of most (98%) of the tested strains to the species level, with good discriminatory power. The majority of strains were correctly identified at the species level with good scores (>2.0) and seven of the tested strains with log score values between 1.7 and 2.0. The MALDI-TOF MS results obtained were consistent with validated internal transcribed spacer (ITS) and/or large subunit (LSU) ribosomal DNA sequencing results. Expanding the mass spectrum database by increasing the number of reference strains for closely related species, including those of nonclinical origin, should enhance the usefulness of MALDI-TOF MS-based diagnostic analysis of these arthroconidial fungi in medical and other laboratories. PMID:23678074

  3. Yeasts Occurring in Surface and Mouth Cavity of Two Chelonian Species, Podocnemis expansa Schweigger and P. unifilis Troschel (Reptilia: Chelonia: Pelomedusidae), in the Javaés River Border of Araguaia National Park in Brazil

    PubMed Central

    de Morais, Paula Benevides; Pimenta, Raphael Sanzio; Tavares, Inara Brito; de Garcia, Virginia; Rosa, Carlos Augusto

    2010-01-01

    Thirty-eight specimens of free-ranging Podocnemis expansa (Amazon turtle) and 22 of P. unifilis (Tracajá) were screened for yeast isolation from surface (plastron, skin, and nails), eye, and mouth cavity. A hundred and eighteen yeast isolates belonging to 39 species were obtained. Debaryomyces hansenii, Candida galli, C. sake, and Rhodotorula mucilaginosa were the most frequent species isolated from these chelonians. Species diversity measured by Shannon's index was shown to be low and a degree of dominance could be detected as species known as potential pathogens were commonly isolated. The effective number of species in plastron of P. expansa was higher than in mouth samples, but not in P. unifilis probably due to dietary factors. P. expansa animals were captured on the beaches, and the superficial yeast populations may include terrestrial species. P. unifilis animals were captured in the water and the yeasts from superficial sites may represent species from river water. PMID:20936145

  4. A phylogenetic study on galactose-containing Candida species based on 18S ribosomal DNA sequences.

    PubMed

    Suzuki, Motofumi; Suh, Sung-Oui; Sugita, Takashi; Nakase, Takashi

    1999-10-01

    Phylogenetic relationships of 33 Candida species containing galactose in the cells were investigated by using 18S ribosomal DNA sequence analysis. Galactose-containing Candida species and galactose-containing species from nine ascomycetous genera were a heterogeneous assemblage. They were divided into three clusters (II, III, and IV) which were phylogenetically distant from cluster I, comprising 9 galactose-lacking Candida species, C. glabrata, C. holmii, C. krusei, C. tropicalis (the type species of Candida), C. albicans, C. viswanathii, C. maltosa, C. parapsilosis, C. guilliermondii, and C. lusitaniae, and 17 related ascomycetous yeasts. These three clusters were also phylogenetically distant from Schizosaccharomyces pombe, which contains galactomannan in its cell wall. Cluster II comprised C. magnoliae, C. vaccinii, C. apis, C. gropengiesseri, C. etchellsii, C. floricola, C. lactiscondensi, Wickerhamiella domercqiae, C. versatilis, C. azyma, C. vanderwaltii, C. pararugosa, C. sorbophila, C. spandovensis, C. galacta, C. ingens, C. incommunis, Yarrowia lipolytica, Galactomyces geotrichum, and Dipodascus albidus. Cluster III comprised C. tepae, C. antillancae and its synonym C. bondarzewiae, C. ancudensis, C. petrohuensis, C. santjacobensis, C. ciferrii (anamorph of Stephanoascus ciferrii), Arxula terrestris, C. castrensis, C. valdiviana, C. paludigena, C. blankii, C. salmanticensis, C. auringiensis, C. bertae, and its synonym C. bertae var. chiloensis, C. edax (anamorph of Stephanoascus smithiae), Arxula adeninivorans, and C. steatolytica (synonym of Zygoascus hellenicus). Cluster IV comprised C. cantarellii, C. vinaria, Dipodascopsis uninucleata, and Lipomyces lipofer. Two galactose-lacking and Q-8-forming species, C. stellata and Pichia pastoris, and 5 galactose-lacking and Q-9-forming species, C. apicola, C. bombi, C. bombicola, C. geochares, and C. insectalens, were included in Cluster II. Two galactose-lacking and Q-9-forming species, C. drimydis and C

  5. Species-specific PCR primers for the rapid identification of yeasts of the genus Zygosaccharomyces.

    PubMed

    Harrison, Elizabeth; Muir, Alastair; Stratford, Malcolm; Wheals, Alan

    2011-06-01

    Species-specific primer pairs that produce a single band of known product size have been developed for members of the Zygosaccharomyces clade including Zygosaccharomyces bailii, Zygosaccharomyces bisporus, Zygosaccharomyces kombuchaensis, Zygosaccharomyces lentus, Zygosaccharomyces machadoi, Zygosaccharomyces mellis and Zygosaccharomyces rouxii. An existing primer pair for the provisional new species Zygosaccharomyces pseudorouxii has been confirmed as specific. The HIS3 gene, encoding imidazole-glycerolphosphate dehydratase, was used as the target gene. This housekeeping gene evolves slowly and is thus well conserved among different isolates, but shows a significant number of base pair changes between even closely related species, sufficient for species-specific primer design. The primers were tested on type and wild strains of the genus Zygosaccharomyces and on members of the Saccharomycetaceae. Sequencing of the D1/D2 region of rDNA was used to confirm the identification of all nonculture collection isolates. This approach used extracted genomic DNA, but in practice, it can be used efficiently with a rapid colony PCR protocol. The method also successfully detected known and new hybrid strains of Z. rouxii and Z. pseudorouxii. The method is rapid, robust and inexpensive. It requires little expertise by the user and is thus useful for preliminary, large-scale screens. PMID:21332639

  6. A new putative Zygosaccharomyces yeast species isolated from traditional balsamic vinegar.

    PubMed

    Solieri, Lisa; Cassanelli, Stefano; Giudici, Paolo

    2007-05-01

    The taxonomic status and species number of the genus Zygosaccharomyces have rapidly changed in the last years. In this study, two new osmotolerant Zygosaccharomyces strains isolated from traditional balsamic vinegar, viz. ABT301 and ABT601, were investigated to elucidate their taxonomic relationships with Zygosaccharomyces rouxii species. A multi-gene sequence approach was employed, including regions of the rDNA repeat [5.8S, two internal transcribed spacers (ITS) and the 26S D1/D2 domain], COX2 mitochondrial gene and two nuclear genes (SOD2 and HIS3). Cloning and sequence analysis of 5.8S-ITS rDNA revealed that these strains bear an unusual polymorphism for this region. Three highly divergent 5.8S-ITS sequences were detected, one identical to Z. rouxii, the other two showing some relatedness to Z. mellis. Sequence and gene number polymorphism was also observed for the protein-encoding nuclear genes SOD2 and HIS3, as two copies for each gene different from those found in Z. rouxii were detected. Analysis of the D1/D2 26S domain showed that ABT301 and ABT601 have only one type of D1/D2 sequence statistically different from that of Z. rouxii. The findings obtained in this work suggest that the genomic background of strains ABT301 and ABT601 is different from the other Zygosaccharomyces species. We speculated that they could belong to a new putative species related to Z. rouxii. PMID:17366521

  7. Formation of In Vitro Mixed-Species Biofilms by Lactobacillus pentosus and Yeasts Isolated from Spanish-Style Green Table Olive Fermentations.

    PubMed

    León-Romero, Ángela; Domínguez-Manzano, Jesús; Garrido-Fernández, Antonio; Arroyo-López, Francisco Noé; Jiménez-Díaz, Rufino

    2016-01-01

    The present work details the in vitro interactions between Lactobacillus pentosus and yeast strains isolated from table olive processing to form mixed biofilms. Among the different pairs assayed, the strongest biofilms were obtained from L. pentosus and Candida boidinii strain cocultures. However, biofilm formation was inhibited in the presence of d-(+)-mannose. In addition, biofilm formation by C. boidinii monoculture was stimulated in the absence of cell-cell contact with L. pentosus. Scanning electron microscopy revealed that a sort of "sticky" material formed by the yeasts contributed to substrate adherence. Hence, the data obtained in this work suggest that yeast-lactobacilli biofilms may be favored by the presence of a specific mate of yeast and L. pentosus, and that more than one mechanism might be implicated in the biofilm formation. This knowledge will help in the design of appropriate mixed starter cultures of L. pentosus-yeast species pairs that are able to improve the quality and safety of Spanish-style green table olive processing. PMID:26567305

  8. Formation of In Vitro Mixed-Species Biofilms by Lactobacillus pentosus and Yeasts Isolated from Spanish-Style Green Table Olive Fermentations

    PubMed Central

    León-Romero, Ángela; Domínguez-Manzano, Jesús; Garrido-Fernández, Antonio; Arroyo-López, Francisco Noé

    2015-01-01

    The present work details the in vitro interactions between Lactobacillus pentosus and yeast strains isolated from table olive processing to form mixed biofilms. Among the different pairs assayed, the strongest biofilms were obtained from L. pentosus and Candida boidinii strain cocultures. However, biofilm formation was inhibited in the presence of d-(+)-mannose. In addition, biofilm formation by C. boidinii monoculture was stimulated in the absence of cell-cell contact with L. pentosus. Scanning electron microscopy revealed that a sort of “sticky” material formed by the yeasts contributed to substrate adherence. Hence, the data obtained in this work suggest that yeast-lactobacilli biofilms may be favored by the presence of a specific mate of yeast and L. pentosus, and that more than one mechanism might be implicated in the biofilm formation. This knowledge will help in the design of appropriate mixed starter cultures of L. pentosus-yeast species pairs that are able to improve the quality and safety of Spanish-style green table olive processing. PMID:26567305

  9. Molecular comparisons for identification of food spoilage yeasts and prediction of species that may develop in different food products

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Spoilage of foods and beverages by yeasts is often characterized by objectionable odors, appearance, taste, texture or build-up of gas in packaging containers, resulting in loss of the product. Seldom is human health compromised by products spoiled by yeasts even though some spoilage is caused by sp...

  10. Papiliotrema siamense f.a., sp. nov., a yeast species isolated from plant leaves.

    PubMed

    Surussawadee, Janjira; Khunnamwong, Pannida; Srisuk, Nantana; Limtong, Savitree

    2014-09-01

    Two strains representing a novel species were isolated from the external surface of a sugar cane leaf (DMKU-SP85(T)) and tissue of a rice leaf (DMKU-RE97) collected in Thailand. 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, the two strains were determined to represent a novel species of the genus Papiliotrema although sexual reproduction was not observed. The sequences of the D1/D2 region of the LSU rRNA gene and ITS region of the two strains were identical, but differed from those of the type strain of Cryptococcus nemorosus by 0.6 % nucleotide substitutions (four nucleotide substitutions out of 597 nucleotides) in the D1/D2 region of the LSU rRNA gene and 1.8 % nucleotide substitutions (nine nucleotide substitutions out of 499 nucleotides) in the ITS region. The name Papiliotrema siamense f.a., sp. nov. is proposed. The type strain is DMKU-SP85(T)( = BCC 69499(T) = CBS 13330(T)). PMID:24925598

  11. Pichia anomala, a new species of yeast-like endosymbionts and its variation in small brown planthopper (Laodelphax striatellus).

    PubMed

    Cao, Wei; Ma, Zheng; Chen, Yolanda H; Yu, Xiaoping

    2015-06-01

    Yeast-like symbionts (YLS) are endosymbionts that promote the growth of delphacid planthoppers (Hemiptera: Delphacidae), some of which are pests on cultivated rice. Identification and characterization of YLS growth can be helpful for pest control, because it has been demonstrated that there is a variety of YLS in rice planthopper and they affected the planthopper's growth and virulence to plant hosts. So, elucidation of the species of YLS in planthopper is crucial for exploiting a new way to control planthopper. In this study, a new isolated of YLS was obtained from the small brown planthopper, Laodelphax striatellus, which was cultured in vitro, simultaneously identified as Pichia anomala based on its phylogenetic analysis. In order to confirm the existence of P. anomala in the L. striatellus body, we used the denaturing gradient gel electrophoresis (DGGE) to identify the YLS and obtain the specific bands for P. anomala. The quantification and localization of P. anomala in L. striatellus samples were determined by fluorescent in situ hybridization (FISH) using genus-specific 18S rDNA targeted probe. The result confirmed that a certain number of P. anomala exist in L. striatellus's abdomen. Subsequently, the variation and copy number of P. anomala in different L. striatellus instars was measured by using absolute quantitative real-time PCR (qPCR), the results indicated that the new isolated strain was closely related to the developmental process of L. striatellus. PMID:25499750

  12. Nonminimally coupled inflation with initial conditions from a preinflation anamorphic contracting era

    NASA Astrophysics Data System (ADS)

    McDonald, John

    2016-08-01

    Inflation due to a nonminimally coupled scalar field, as first proposed by Salopek, Bardeen and Bond (SBB), is in good agreement with the observed value of the spectral index and constraints on the tensor-to-scalar ratio. Here we explore the possibility that SBB inflation represents the late stage of a Universe which emerges from an early contracting era. We present a model in which the Universe smoothly transitions from an anamorphic contracting era to late-time SBB inflation without encountering a singular bounce. This corresponds to a continuous expansion in the Einstein frame throughout. We show that the anamorphic contracting era is able to provide the smooth superhorizon initial conditions necessary for subsequent SBB inflation to occur. The model predicts corrections to the nonminimal coupling, kinetic term and potential of SBB inflation which can observably increase the spectral index relative to its SBB prediction.

  13. Identification of cultured isolates of clinically important yeast species using fluorescent fragment length analysis of the amplified internally transcribed rRNA spacer 2 region

    PubMed Central

    De Baere, Thierry; Claeys, Geert; Swinne, Danielle; Massonet, Caroline; Verschraegen, Gerda; Muylaert, An; Vaneechoutte, Mario

    2002-01-01

    Background The number of patients with yeast infection has increased during the last years. Also the variety of species of clinical importance has increased. Correct species identification is often important for efficient therapy, but is currently mostly based on phenotypic features and is sometimes time-consuming and depends largely on the expertise of technicians. Therefore, we evaluated the feasibility of PCR-based amplification of the internally transcribed spacer region 2 (ITS2), followed by fragment size analysis on the ABI Prism 310 for the identification of clinically important yeasts. Results A rapid DNA-extraction method, based on simple boiling-freezing was introduced. Of the 26 species tested, 22 could be identified unambiguously by scoring the length of the ITS2-region. No distinction could be made between the species Trichosporon asteroides and T. inkin or between T. mucoides and T. ovoides. The two varieties of Cryptococcus neoformans (var. neoformans and var. gattii) could be differentiated from each other due to a one bp length difference of the ITS2 fragment. The three Cryptococcus laurentii isolates were split into two groups according to their ITS2-fragment lengths, in correspondence with the phylogenetic groups described previously. Since the obtained fragment lengths compare well to those described previously and could be exchanged between two laboratories, an internationally usable library of ITS2 fragment lengths can be constructed. Conclusions The existing ITS2 size based library enables identification of most of the clinically important yeast species within 6 hours starting from a single colony and can be easily updated when new species are described. Data can be exchanged between laboratories. PMID:12139769

  14. Temperature Sensitivity Conferred by ligA Alleles from Psychrophilic Bacteria upon Substitution in Mesophilic Bacteria and a Yeast Species

    PubMed Central

    Pankowski, Jarosław A.; Puckett, Stephanie M.

    2016-01-01

    We have assembled a collection of 13 psychrophilic ligA alleles that can serve as genetic elements for engineering mesophiles to a temperature-sensitive (TS) phenotype. When these ligA alleles were substituted into Francisella novicida, they conferred a TS phenotype with restrictive temperatures between 33 and 39°C. When the F. novicida ligA hybrid strains were plated above their restrictive temperatures, eight of them generated temperature-resistant variants. For two alleles, the mutations that led to temperature resistance clustered near the 5′ end of the gene, and the mutations increased the predicted strength of the ribosome binding site at least 3-fold. Four F. novicida ligA hybrid strains generated no temperature-resistant variants at a detectable level. These results suggest that multiple mutations are needed to create temperature-resistant variants of these ligA gene products. One ligA allele was isolated from a Colwellia species that has a maximal growth temperature of 12°C, and this allele supported growth of F. novicida only as a hybrid between the psychrophilic and the F. novicida ligA genes. However, the full psychrophilic gene alone supported the growth of Salmonella enterica, imparting a restrictive temperature of 27°C. We also tested two ligA alleles from two Pseudoalteromonas strains for their ability to support the viability of a Saccharomyces cerevisiae strain that lacked its essential gene, CDC9, encoding an ATP-dependent DNA ligase. In both cases, the psychrophilic bacterial alleles supported yeast viability and their expression generated TS phenotypes. This collection of ligA alleles should be useful in engineering bacteria, and possibly eukaryotic microbes, to predictable TS phenotypes. PMID:26773080

  15. Temperature Sensitivity Conferred by ligA Alleles from Psychrophilic Bacteria upon Substitution in Mesophilic Bacteria and a Yeast Species.

    PubMed

    Pankowski, Jarosław A; Puckett, Stephanie M; Nano, Francis E

    2016-01-01

    We have assembled a collection of 13 psychrophilic ligA alleles that can serve as genetic elements for engineering mesophiles to a temperature-sensitive (TS) phenotype. When these ligA alleles were substituted into Francisella novicida, they conferred a TS phenotype with restrictive temperatures between 33 and 39°C. When the F. novicida ligA hybrid strains were plated above their restrictive temperatures, eight of them generated temperature-resistant variants. For two alleles, the mutations that led to temperature resistance clustered near the 5' end of the gene, and the mutations increased the predicted strength of the ribosome binding site at least 3-fold. Four F. novicida ligA hybrid strains generated no temperature-resistant variants at a detectable level. These results suggest that multiple mutations are needed to create temperature-resistant variants of these ligA gene products. One ligA allele was isolated from a Colwellia species that has a maximal growth temperature of 12°C, and this allele supported growth of F. novicida only as a hybrid between the psychrophilic and the F. novicida ligA genes. However, the full psychrophilic gene alone supported the growth of Salmonella enterica, imparting a restrictive temperature of 27°C. We also tested two ligA alleles from two Pseudoalteromonas strains for their ability to support the viability of a Saccharomyces cerevisiae strain that lacked its essential gene, CDC9, encoding an ATP-dependent DNA ligase. In both cases, the psychrophilic bacterial alleles supported yeast viability and their expression generated TS phenotypes. This collection of ligA alleles should be useful in engineering bacteria, and possibly eukaryotic microbes, to predictable TS phenotypes. PMID:26773080

  16. The diversity and extracellular enzymatic activities of yeasts isolated from water tanks of Vriesea minarum, an endangered bromeliad species in Brazil, and the description of Occultifur brasiliensis f.a., sp. nov.

    PubMed

    Gomes, Fátima C O; Safar, Silvana V B; Marques, Andrea R; Medeiros, Adriana O; Santos, Ana Raquel O; Carvalho, Cláudia; Lachance, Marc-André; Sampaio, José Paulo; Rosa, Carlos A

    2015-02-01

    The diversity of yeast species collected from the bromeliad tanks of Vriesea minarum, an endangered bromeliad species, and their ability to produce extracellular enzymes were studied. Water samples were collected from 30 tanks of bromeliads living in a rupestrian field site located at Serrada Piedade, Minas Gerais state, Brazil, during both the dry and rainy seasons. Thirty-six species were isolated, representing 22 basidiomycetous and 14 ascomycetous species. Occultifur sp., Cryptococcus podzolicus and Cryptococcus sp. 1 were the prevalent basidiomycetous species. The yeast-like fungus from the order Myriangiales, Candida silvae and Aureobasidium pullulans were the most frequent ascomycetous species. The diversity of the yeast communities obtained between seasons was not significantly different, but the yeast composition per bromeliad was different between seasons. These results suggest that there is significant spatial heterogeneity in the composition of populations of the yeast communities within bromeliad tanks, independent of the season. Among the 352 yeast isolates tested, 282 showed at least one enzymatic activity. Protease activity was the most widely expressed extracellular enzymatic activity, followed by xylanase, amylase, pectinase and cellulase activities. These enzymes may increase the carbon and nitrogen availability for the microbial food web in the bromeliad tank of V. minarum. Sequence analyses revealed the existence of 10 new species, indicating that bromeliad tanks are important sources of new yeasts. The novel species Occultifur brasiliensis, f.a., sp. nov., is proposed to accommodate the most frequently isolated yeast associated with V. minarum. The type strain of O. brasiliensis, f.a., sp. nov. is UFMG-CM-Y375(T) (= CBS 12687(T)). The Mycobank number is MB 809816. PMID:25515414

  17. Endomelanconiopsis, a new anamorph genus in the Botryosphaeriaceae

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The new species Endomelanconium endphyticum was common among endophytes isolated from healthy leaves of Theobroma cacao (cacao, Malvaceae) and Heisteria concinna (Oleaceae) in Panama. A total of fifteen endophytic cultures representing both hosts were selected for sequencing and morphological chara...

  18. A laboratory-based study on patients with Parkinson’s disease and seborrheic dermatitis: the presence and density of Malassezia yeasts, their different species and enzymes production

    PubMed Central

    2014-01-01

    Background Seborrheic dermatitis (SD) and Parkinson’s disease (PD) are frequently associated conditions. Aims of this study were: to determine severity of SD, presence of different species and density of Malassezia yeasts; to assess yeast lipases and phosphatases production in vitro and to compare these results between SD patients with and without PD. Methods This case–control prospective study was conducted at the Dermatology and Neurology Units, Clinical Centre of Serbia and at the National Medical Mycology Reference Laboratory, University of Belgrade Medical School, Serbia. A total of 90 patients and 70 healthy controls (HC) were investigated: 60 patients with SD (SDN) and 30 patients with SD and PD (SDP). Culture-based mycological examination was carried out on lesional skin (LS) and non-lesional skin (NLS). A yeasts density was determined by counting the Malassezia colony forming units per tape (CFU/tape). Enzymes production by isolated Malassezia was investigated. Results The most patients with SD were male (76.7%; SDP and 63.3%; SDN) and the intensity of SD was dominantly severe or moderate (76.7%; SDP and 75%; SDN). The presence of Malasseziа was high on LS in both groups (87.3%; SDP and 86.7%; SDN) (p=0.667). The highest yeasts density (mean CFU/tape=67.8) was detected on LS in 53% of SDP group and in 21.7% of SDN group (mean CFU/tape=31.9) (p < 0.01). The presence of negative cultures was lower in SDP group (13.3%) in comparison to HC and SDN groups (37% and 31.7%, respectively). Malassezia density on NLS in SDP group (mean CFU/tape=44.3) was significantly higher in comparison to SDN and HC (p=0.018). M. globosa was the most abundant species identified amongst isolates from the SDP group (42.3%) and exhibited high production of phosphatase and lipase in vitro. Conclusion From this laboratory-based study a positive correlation between SD, PD, M. globosa incidence, high yeast density and high phosphatase and lipase activity was established. Our data

  19. Cytological Characterization of Anamorphic Fungus Lecanicillium pui and Its Relationship with Chinese Caterpillar Mushroom, Ophiocordyceps sinensis (Ascomycetes).

    PubMed

    Lei, Wei; Zhang, Guren; Wu, Guangguo; Liu, Xin

    2016-01-01

    Ophiocordyceps sinensis (syn. Cordyceps sinensis), one of the most valuable medicinal mushrooms, has great economic importance on the Tibetan Plateau. We isolated an anamorphic fungus Lecanicillium pui from natural O. sinensis specimens and found that the optimal temperature for its culture on potato dextrose agar media was 25°C. Cell ultrastructure in L. pui hyphae and spores was characterized by transmission electron microscopy, and it was observed that some primary organelles showed the typical fungal features. Five chemical elements were determined in this fungus and niobium was discovered for the first time even with trace amounts. A species-specific method, nested polymerase chain reaction, was established to investigate the colonization of this fungus. Thus, the extensive distribution of L. pui on O. sinensis, in the shape of hyphae or mycelia, suggested that it may have subtle and chronic effects on the growth of the O. sinensis teleomorphic stage. These findings provide a potential reference, in the view of microbial ecology, for the study on the occurrence and mechanism of development of O. sinensis. PMID:27279447

  20. Role of the yeast acetyltransferase Mpr1 in oxidative stress: regulation of oxygen reactive species caused by a toxic proline catabolism intermediate.

    PubMed

    Nomura, Michiyo; Takagi, Hiroshi

    2004-08-24

    The MPR1 gene, which is found in the Sigma1278b strain but is not present in the sequenced laboratory strain S288C, of the budding yeast Saccharomyces cerevisiae encodes a previously uncharacterized N-acetyltransferase that detoxifies the proline analogue azetidine-2-carboxylate (AZC). However, it is unlikely that AZC is a natural substrate of Mpr1 because AZC is found only in some plant species. In our search for the physiological function of Mpr1, we found that mpr1-disrupted cells were hypersensitive to oxidative stresses and contained increased levels of reactive oxygen species (ROS). In contrast, overexpression of MPR1 leads to an increase in cell viability and a decrease in ROS level after oxidative treatments. These results indicate that Mpr1 can reduce intracellular oxidation levels. Because put2-disrupted yeast cells lacking Delta(1)-pyrroline-5-carboxylate (P5C) dehydrogenase have increased ROS, we examined the role of Mpr1 in put2-disrupted strains. When grown on media containing urea and proline as the nitrogen source, put2-disrupted cells did not grow as well as WT cells and accumulated intracellular levels of P5C that were first detected in yeast cells and ROS. On the other hand, put2-disrupted cells that overexpressed MPR1 had considerably lower ROS levels. In vitro studies with bacterially expressed Mpr1 demonstrated that Mpr1 can acetylate P5C, or, more likely, its equilibrium compound glutamate-gamma-semialdehyde, at neutral pH. These results suggest that the proline catabolism intermediate P5C is toxic to yeast cells because of the formation of ROS, and Mpr1 regulates the ROS level under P5C-induced oxidative stress. PMID:15308773

  1. Electrospray ionization-tandem mass spectrometry analysis of phospholipid molecular species from Antarctic and non-Antarctic yeasts.

    PubMed

    Bhuiyan, Mohammad; Tucker, David; Watson, Kenneth

    2014-10-01

    High performance liquid chromatography-electrospray ionization tandem mass spectrometry was applied to the comprehensive analysis of phospholipids from seven Antarctic and seven non-Antarctic yeasts. Identification of specific fatty acyl moieties to the sn-1 and sn-2 positions of phosphatidylethanolamine (PE), phosphatidylcholine (PC), phosphatidylserine (PS) and phosphatidylinositol (PI) were determined by relative abundance of fragment ions associated with formation of carboxylate anions and loss of fragment ions as free fatty carboxylic acid and ketene. Modulations with growth temperature in fatty acyl moieties in the sn-1 and sn-2 positions were characterized. Principal component analysis demonstrated that PE, PC and to a lesser extent PS, but not PI, were grouped into three distinct clusters consisting of seven Antarctic yeasts (Cryptococcus victoriae, Holtermanniella wattica, H. nyarrowii, Candida psychrophila, Leucosporidium fellii, Glaciozyma antarctica, Rhodotorula mucilaginosa), four non-Antarctic yeasts (C. albicans, Zygosaccharomyces rouxii, Cr. humicolus, R. mucilaginosa) and three strains of Saccharomyces cerevisiae. PMID:25019517

  2. Design of anamorphic magnification high-numerical aperture objective for extreme ultraviolet lithography by curvatures combination method.

    PubMed

    Liu, Yan; Li, Yanqiu; Cao, Zhen

    2016-06-20

    An anamorphic magnification extreme ultraviolet (EUV) lithographic objective could increase the size of the exposure field at a wafer in the orthogonal scanning direction to improve the throughput of the lithographic system. In this paper, we present a curvatures combination method for an anamorphic magnification EUV lithographic objective with high numerical aperture (NA). This method achieves an anamorphic magnification initial structure by use of the double-curvature surfaces, which are formed by combining the curvatures of the corresponding surfaces into two coaxial spherical systems. A series of control measures is taken to design the two coaxial spherical systems for ensuring the rationalities of the initial structure and the surfaces after combining. The image quality of the anamorphic initial structure is optimized by a gradual optimization process. Finally, as an example, we design an Mx1/4 and My1/8 anamorphic magnification EUV lithographic objective with the presented design method. This objective achieves 0.5 NA and a 26  mm×16.5  mm exposure field at the wafer. The wavefront error RMS reaches 0.06λ (λ=13.5  nm), and the distortion is less than 2.8 nm. The design result proves the availability of the curvatures combination method. PMID:27409118

  3. Hypocrea britdaniae and H. foliicola: two remarkable new European species

    PubMed Central

    Jaklitsch, Walter M.; Voglmayr, Hermann

    2014-01-01

    Two new species of Hypocrea are added here to the European funga. Hypocrea britdaniae, a fungus with unknown anamorph and large, conspicuous stromata resembling basidiomata of a corticiaceous fungus, is a sister species to the Longibrachiatum clade, while H. foliicola, a leaf-dwelling species that forms pulvinate stromata, is recognized as an additional member of the pachybasium core group. Hypocrea foliicola sporulates in culture in a reduced verticillium-like manner, while it produces a white, typical pachybasium-like anamorph in nature. Ecologically H. foliicola is remarkable in inhabiting leaves, a substrate rarely recorded for Hypocrea. All relevant morphological teleomorphic and anamorphic traits are given. The phylogenetic placement of the new species within Hypocrea/Trichoderma was determined with combined analyses of rpb2 and tef1 exon sequences. PMID:22505436

  4. The Evaluation of the Distribution of Yeast like Fungi 'Candida Species' at a Tertiary Care Center in Western Turkey

    PubMed Central

    Ece, Gulfem; Samlioglu, Pinar; Akkoclu, Gulgun; Atalay, Sabri; Kose, Sukran

    2012-01-01

    Objective: Candida infections have increased due to transplant patients, prolonged ICU stay and invasive procedures. The most common isolated strain is C. albicans. The aim of this study was to evaluate the distribution of Candida isolates at Tepecik Education and Research Hospital. Materials and Methods: Yeast like fungi were isolated between 13.01.2010 and 19.08.2011 at Mycology Laboratory. The identification was done by conventional methods and carbohydrate assimilation profile using the ID32C identification system (Biomerieux, France). Results: Yeast like fungi were isolated from 337 clinical specimens. They consisted of urine, blood culture, respiratory specimen and wound. The most isolated yeast strains were C.albicans (38.6%), C.tropicalis (13.9%), C. parapsilosis (28.4%), C.glabrata (7.4%), C.krusei (3.8%). Conclusion: Recently there is an increment in Candida infections. In this study the most common strain was C.albicans and the rate C. glabrata and C. krusei isolates were lower than expected. C. parapsilosis was the most isolated strain in blood cultures and this may be due to invasive procedures and the use of indwelling catheters. PMID:23028245

  5. An isolate of Arthroderma benhamiae with Trichophyton mentagrophytes var. erinacei anamorph isolated from a four-toed hedgehog (Atelerix albiventris) in Japan.

    PubMed

    Takahashi, Yoko; Haritani, Kuniko; Sano, Ayako; Takizawa, Kayoko; Fukushima, Kazutaka; Miyaji, Makoto; Nishimura, Kazuko

    2002-01-01

    A female four-toed hedgehog probably imported from Africa and kept as a pet by a family suffered from depilation and mite (Caparinia tripilis) infection. Depilated quills were inoculated on a commercially available medium and an isolate of the dermatophytes was obtained. A giant colony after 14 days incubation on yeast extract Sabourauds agar had a central umbo with white granular surface and a yellow pigment ring in the reverse. The hedgehog isolate produced numerous elongated microconidia singly attached along the sides of hyphae. Macroconidia were somewhat irregular in shape and size and 2-6 septa. Abundant intermediate sized spores between micro- and macro conidia and few spirals were observed. Hair perforation and urease activity tests were positive. Maximum growth temperature was 40 C. In the mating tests using the tester strains of both African and Americano-European races of Arthroderma benhamiae, the strain produced numerous gymnothecia only when paired with the African race mating type minus(-). In addition, 591 bases of the internal transcribed spacer region of the ribosomal RNA gene including the 5.8S region (ITS1-5.8S-ITS2) were sequenced and corresponded to those of T. mentagrophytes var. erinacei (DDBJ/EMBL/GenBank accession numbers Z97996 and Z97997) by more than 99.7%. Therefore, our case is the first isolation of A. benhamiae with T. mentagrophytes var. erinacei anamorph in Japan. PMID:12402026

  6. Identification of three yeast species using the conventional and internal transcribed spacer region sequencing methods as first or second global record from human superficial infections.

    PubMed

    Abdel-Sater, Mohamed Ahmed; Moubasher, Abdel-Aal Hassan; Soliman, Zeinab

    2016-10-01

    During the mycological analysis of skin and nail samples taken from patients with onychomycosis and tineas in Assiut city, it is interesting to report that yeast fungi were the main causal agents being cultured from 45.79% of total cases. In general, 21 species of yeast were isolated. Some of these are reported for the first time from clinical specimens. From the literature available up-to-date around the world, this study reports for the first time Saccharomycopsis fibuligera as the causal agent of four clinical cases: two onychomycoses, one tinea capitis and one tinea amiantacea. Also, it is reported here the second record for Trichosporon dohaense from a case of onychomycosis of a 40-year-old woman (after its original description in 2009 by Taj-Aldeen et al. J Clin Microbiol 47: 1791). Candida galli was also reported for the first time from clinical specimen (tinea unguium) in 2014 by Galán-Sánchez et al. Mycopathol 178: 303, and this study reports the second case of onychomycosis by C. galli. These strains were identified on the basis of their phenotypic, biochemical, physiological and genotypic features. Strains and internal transcribed spacer (ITS) gene sequences of these species are deposited at Assiut University Mycological Center Culture Collection (AUMC) and National Center for Biotechnological Information (NCBI) respectively. PMID:27392537

  7. Lachancea quebecensis sp. nov., a yeast species consistently isolated from tree bark in the Canadian province of Québec.

    PubMed

    Freel, Kelle C; Charron, Guillaume; Leducq, Jean-Baptiste; Landry, Christian R; Schacherer, Joseph

    2015-10-01

    A thorough sampling of maple, oak, birch, and apple tree bark in North America yielded a set of isolates that represent a yeast species not yet formally described. The strains obtained were all isolated from the Canadian province of Québec. These four isolates have identical electrophoretic karyotypes, distinct from other species of the genus Lachancea, and are most closely related to the formally recognized species Lachancea thermotolerans according to the D1/D2 domain of the LSU rDNA gene and 5.8S–ITS region. Previous studies revealed the existence of a population of strains closely related to L. thermotolerans, with unique D1/D2 sequences and the ability to grow on melibiose, which is also true for these isolates. The sequences obtained here (for the D1/D2, and 5.8S–ITS region) are identical among the four strains, and in a phylogenetic analysis of the D1/D2 region, the strains form a distinct clade with the previously described population closely related to L. thermotolerans, composed of isolates from Japan, as well as from the provinces of Ontario and Québec in Canada. On the basis of select physiological and phylogenetic characteristics, a novel ascosporogenous yeast species, Lachancea quebecensis sp. nov., is proposed. The type strain LL11_022T ( = CBS 14138T = CLIB 1763T = UCDFST 15-106T) was isolated from maple tree bark in the Station Duchesnay, QC region of Québec, Canada. The MycoBank number is MB811749. PMID:26297665

  8. Yeast Infections

    MedlinePlus

    ... antibiotics, it can multiply and cause an infection. Yeast infections affect different parts of the body in different ways: Thrush is a yeast infection that causes white patches in your mouth Candida ...

  9. Stray light characterization of an InGaAs anamorphic hyperspectral imager.

    PubMed

    Lin, Mike; Swanson, Rand; Moon, Thomas; Smith, Casey; Kehoe, Michael; Brown, Steven W; Lykke, Keith R

    2010-08-01

    Compact hyperspectral sensors potentially have a wide range of applications, including machine vision, quality control, and surveillance from small Unmanned Aerial Vehicles (UAVs). With the development of Indium Gallium Arsenide (InGaAs) focal plane arrays, much of the Short Wave Infra-Red (SWIR) spectral regime can be accessed with a small hyperspectral imaging system, thereby substantially expanding hyperspectral sensing capabilities. To fully realize this potential, system performance must be well-understood. Here, stray light characterization of a recently-developed push-broom hyperspectral sensor sensitive in the 1 microm -1.7 microm spectral regime is described. The sensor utilizes anamorphic fore-optics that partially decouple image formation along the spatial and spectral axes of the instrument. This design benefits from a reduction in complexity over standard high-performance spectrometer optical designs while maintaining excellent aberration control and spatial and spectral distortion characteristics. The stray light performance characteristics of the anamorphic imaging spectrometer were measured using the spectral irradiance and radiance responsivity calibrations using uniform sources (SIRCUS) facility at the National Institute of Standards and Technology (NIST). A description of the measurements and results are presented. Additionally, a stray-light matrix was assembled for the instrument to improve the instrument's spectral accuracy. Transmittance of a silicon wafer was measured to validate this approach. PMID:20721136

  10. Isaria takamizusanensis is the anamorph of Cordyceps ryogamimontana, warranting a new combination, Purpureocillium takamizusanense comb. nov.

    PubMed

    Ban, Sayaka; Azuma, Yuta; Sato, Hiroki; Suzuki, Ken-Ichiro; Nakagiri, Akira

    2015-08-01

    The entomogenous anamorphic fungus Isaria takamizusanensis has not been resolved clearly in its teleomorphic state. We succeeded in inducing ascostroma formation by incubating conidiomata of I. takamizusanensis on cicada adults in a moist chamber. We observed the ascostroma and conducted a phylogenetic analysis based on ITS rDNA and EF-1α genes. The morphology of the ascostroma was identical to that of Cordyceps ryogamimontana. In the phylogenetic tree inferred from EF-1α, the isolate from the partspores grouped with nine strains derived from conidia of I. takamizusanensis, which was distinct from a clade including Purpureocillium lilacinum. Moreover, a conidial structure identical to that of I. takamizusanensis was rediscovered on the holotype specimen of C. ryogamimontana. As a result, we propose a new name, Purpureocillium takamizusanense, which is a combination of the teleomorph-anamorph connection of C. ryogamimontana-I. takamizusanensis, in accordance with the 'one fungus, one name' concept of the International Code of Nomenclature for Algae, Fungi, and Plants (ICN). PMID:25911534

  11. Image slicing with a twist: spatial and spectral Nyquist sampling without anamorphic optics

    NASA Astrophysics Data System (ADS)

    Tecza, Matthias

    2014-07-01

    Integral field spectrographs have become mainstream instruments at modern telescopes because of their efficient way of collecting data-cubes. Image slicer based integral field spectrographs achieve the highest fill-factor on the detector, but due to the need to Nyquist-sample the spectra, their spatial sampling on the sky is rectangular. Using anamorphic pre-optics before the image slicer overcomes this effect further maximising the fill-factor, but introduces optical aberrations, throughput losses, and additional alignment and calibration requirements, compromising overall instrument performance. In this paper I present a concept for an image-slicer that achieves both spatial and spectral Nyquist-sampling without anamorphic pre-optics. Rotating each slitlet by 45° with respect to the dispersion direction, and arranging them into a saw-tooth pseudo-slit, leads to a lozenge shaped sampling element on the sky, however, the centres of the lozenges lie on a regular and square grid, satisfying the Nyquist sampling criterion in both spatial directions.

  12. PHYLOGENETICS OF SACCHAROMYCETALES, THE ASCOMYCETE YEASTS

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Ascomycete yeasts (Phylum Ascomycota: Subphylum Saccharomycotina: Class Saccharomycetes: Order Saccharomycetales) comprise a monophyletic lineage with a single order of about 1000 known species. These yeasts live as saprobes, often in association with plants, animals, and their interfaces. A few s...

  13. Activity Profile In Vitro of Micafungin against Spanish Clinical Isolates of Common and Emerging Species of Yeasts and Molds▿

    PubMed Central

    Cuenca-Estrella, Manuel; Gomez-Lopez, Alicia; Mellado, Emilia; Monzon, Araceli; Buitrago, Maria J.; Rodriguez-Tudela, Juan L.

    2009-01-01

    A collection of 2,278 isolates belonging to 86 different fungal species was tested with micafungin and eight other drugs using the EUCAST procedures. Micafungin was active against species of Candida and Aspergillus (even azole-resistant species) as well as Penicillium spp., Scedosporium apiospermum, and Acremonium spp. It was inactive for species of Basidiomycota and Mucorales and for multiresistant species such as those of Fusarium. PMID:19223630

  14. Comparative physiology and fermentation performance of Saaz and Frohberg lager yeast strains and the parental species Saccharomyces eubayanus.

    PubMed

    Gibson, Brian R; Storgårds, Erna; Krogerus, Kristoffer; Vidgren, Virve

    2013-07-01

    Two distinct genetic groups (Saaz and Frohberg) exist within the hybrid Saccharomyces pastorianus (S. cerevisiae × S. eubayanus) taxon. However, physiological/technological differences that exist between the two groups are not known. Fermentative capability of the parental S. eubayanus has likewise never been studied. Here, 58 lager strains were screened to determine which hybrid group they belonged to, and selected strains were characterized to determine salient characteristics. In 15 °P all-malt wort fermentations at 22 °C, Frohberg strains showed greater growth and superior fermentation (80% apparent attenuation, 6.5% alcohol by volume in 3-4 days) compared to all other strains and maintained highest viability values (>93%). Fermentation with S. eubayanus was poor at the same temperature (33% apparent attenuation, 2.7% alcohol by volume at 6 days and viability reduced to 75%). Saaz strains and S. eubayanus were the least sensitive to cold (10 °C), though this did not translate to greater fermentation performance. Fermentation with S. eubayanus was poor at 10 °C but equal to or greater than that of the Saaz strains. Performance of Saaz yeast/S. eubayanus was limited by an inability to use wort maltotriose. [(14)C]-Maltotriose transport assays also showed negligible activity in these strains (≤0.5 µmol min(-1) g(-1) dry yeast). Beers from Saaz fermentations were characterized by two- to sixfold lower production of the flavour compounds methyl butanol, ethyl acetate and 3-methylbutyl acetate compared to Frohberg strains. Higher alcohol and ester production by S. eubayanus was similar to that of Frohberg strains. PMID:23695993

  15. Formic Acid-Based Direct, On-Plate Testing of Yeast and Corynebacterium Species by Bruker Biotyper Matrix-Assisted Laser Desorption Ionization–Time of Flight Mass Spectrometry

    PubMed Central

    Theel, Elitza S.; Schmitt, Bryan H.; Hall, Leslie; Cunningham, Scott A.; Walchak, Robert C.; Patel, Robin

    2012-01-01

    An on-plate testing method using formic acid was evaluated on the Bruker Biotyper matrix-assisted laser desorption ionization–time of flight (MALDI-TOF) mass spectrometry system using 90 yeast and 78 Corynebacterium species isolates, and 95.6 and 81.1% of yeast and 96.1 and 92.3% of Corynebacterium isolates were correctly identified to the genus and species levels, respectively. The on-plate method using formic acid yielded identification percentages similar to those for the conventional but more laborious tube-based extraction. PMID:22760034

  16. Lactic Acid Bacterium and Yeast Microbiotas of 19 Sourdoughs Used for Traditional/Typical Italian Breads: Interactions between Ingredients and Microbial Species Diversity

    PubMed Central

    Minervini, Fabio; Di Cagno, Raffaella; Lattanzi, Anna; Antonielli, Livio; Cardinali, Gianluigi; Cappelle, Stefan; Gobbetti, Marco

    2012-01-01

    The study of the microbiotas of 19 Italian sourdoughs used for the manufacture of traditional/typical breads allowed the identification, through a culture-dependent approach, of 20 and 4 species of lactic acid bacteria (LAB) and yeasts, respectively. Numerically, the most frequent LAB isolates were Lactobacillus sanfranciscensis (ca. 28% of the total LAB isolates), Lactobacillus plantarum (ca. 16%), and Lactobacillus paralimentarius (ca. 14%). Saccharomyces cerevisiae was identified in 16 sourdoughs. Candida humilis, Kazachstania barnettii, and Kazachstania exigua were also identified. As shown by principal component analysis (PCA), a correlation was found between the ingredients, especially the type of flour, the microbial community, and the biochemical features of sourdoughs. Triticum durum flours were characterized by the high level of maltose, glucose, fructose, and free amino acids (FAA) correlated with the sole or main presence of obligately heterofermentative LAB, the lowest number of facultatively heterofermentative strains, and the low cell density of yeasts in the mature sourdoughs. This study highlighted, through a comprehensive and comparative approach, the dominant microbiotas of 19 Italian sourdoughs, which determined some of the peculiarities of the resulting traditional/typical Italian breads. PMID:22156414

  17. Volatile flavour profile of reduced alcohol wines fermented with the non-conventional yeast species Metschnikowia pulcherrima and Saccharomyces uvarum.

    PubMed

    Varela, C; Sengler, F; Solomon, M; Curtin, C

    2016-10-15

    Production of quality wines with decreased alcohol concentration continues to be one of the major challenges facing wine producers. Therefore, there is considerable interest in the isolation or generation of wine yeasts less efficient at transforming grape sugars into ethanol. We recently demonstrated that Metschnikowia pulcherrima AWRI1149 and Saccharomyces uvarum AWRI2846 were both able to produce reduced alcohol wine when used in sequential inoculation with Saccharomyces cerevisiae. This effect is additive when both strains are co-inoculated in grape must. Here we describe the volatile flavour profile of Chardonnay and Shiraz wines produced with these two strains. Wines fermented with M. pulcherrima showed concentrations of ethyl acetate likely to affect negatively wine aroma. Wines fermented with S. uvarum and with a combination of M. pulcherrima and S. uvarum were characterised by increased concentrations of 2-phenyl ethanol and 2-phenylethyl acetate, both associated with positive sensory attributes. PMID:27173534

  18. Full-parallax 360 degrees horizontal viewing integral imaging using anamorphic optics

    NASA Astrophysics Data System (ADS)

    Erdenebat, Munkh-Uchral; Baasantseren, Ganbat; Park, Jae-Hyeung; Kim, Nam; Kwon, Ki-Chul; Jang, Young-Hee; Yoo, Kwan-Hee

    2011-03-01

    We propose full-parallax integral imaging display with 360 degree horizontal viewing angle. Two-dimensional (2D) elemental images are projected by a high-speed DMD projector and integrated into three-dimensional (3D) image by a lens array. The anamorphic optic system tailors the horizontal and vertical viewing angles of the integrated 3D images in order to obtain high angular ray density in horizontal direction and large viewing angle in vertical direction. Finally, the mirror screen that rotates in synchronization with the DMD projector presents the integrated 3D images to desired direction accordingly. Full-parallax and 360 degree horizontal viewing angle 3D images with both of monocular and binocular depth cues can be achieved by the proposed method.

  19. Oxygen requirements of yeasts.

    PubMed Central

    Visser, W; Scheffers, W A; Batenburg-van der Vegte, W H; van Dijken, J P

    1990-01-01

    Type species of 75 yeast genera were examined for their ability to grow anaerobically in complex and mineral media. To define anaerobic conditions, we added a redox indicator, resazurin, to the media to determine low redox potentials. All strains tested were capable of fermenting glucose to ethanol in oxygen-limited shake-flask cultures, even those of species generally regarded as nonfermentative. However, only 23% of the yeast species tested grew under anaerobic conditions. A comparative study with a number of selected strains revealed that Saccharomyces cerevisiae stands out as a yeast capable of rapid growth at low redox potentials. Other yeasts, such as Torulaspora delbrueckii and Candida tropicalis, grew poorly mu max, 0.03 and 0.05 h-1, respectively) under anaerobic conditions in mineral medium supplemented with Tween 80 and ergosterol. The latter organisms grew rapidly under oxygen limitation and then displayed a high rate of alcoholic fermentation. It can be concluded that these yeasts have hitherto-unidentified oxygen requirements for growth. Images PMID:2082825

  20. Microbiota-Gut-Brain Axis: Yeast Species Isolated from Stool Samples of Children with Suspected or Diagnosed Autism Spectrum Disorders and In Vitro Susceptibility Against Nystatin and Fluconazole.

    PubMed

    Kantarcioglu, A Serda; Kiraz, Nuri; Aydin, Ahmet

    2016-02-01

    Autism spectrum disorder (ASD) is a general term for a group of complex neurodevelopmental disorders of brain development that limits a person's ability to function normally. Etiology has not been clearly defined up to date. However, gut microbiota and the bidirectional communication between the gastrointestinal tract and brain, the so-called microbiota-gut-brain axis, are hypothesized, which may be involved in the etiology of several mental disorders. Recent reports suggest that Candida, particularly Candida albicans, growth in intestines may cause lower absorption of carbohydrates and minerals and higher toxin levels which are thought to contribute autistic behaviors. The aim of this study was to identify the 3-year deposited yeasts isolated from stool samples of children with diagnosed or suspected ASD and to determine in vitro activity of nystatin and fluconazole against these isolates using Clinical Laboratory Standards Institute M27-A3 guidelines. A 17-year retrospective assessment was also done using our laboratory records. Among the species identified, intrinsically fluconazole-resistant Candida krusei (19.8 %) and Candida glabrata (14.8 %) with elevated MICs were remarkable. Overall, C. albicans (57.4 %) was the most commonly isolated species in 17 years. The species identification and/or antifungal susceptibility tests have to be performed using the strain isolated from stool sample, to select the appropriate antifungal agent, if antimycotic therapy is needed. PMID:26442855

  1. Extracellular Polysaccharides Produced by Yeasts and Yeast-Like Fungi

    NASA Astrophysics Data System (ADS)

    van Bogaert, Inge N. A.; de Maeseneire, Sofie L.; Vandamme, Erick J.

    Several yeasts and yeast-like fungi are known to produce extracellular polysaccharides. Most of these contain D-mannose, either alone or in combination with other sugars or phosphate. A large chemical and structural variability is found between yeast species and even among different strains. The types of polymers that are synthesized can be chemically characterized as mannans, glucans, phosphoman-nans, galactomannans, glucomannans and glucuronoxylomannans. Despite these differences, almost all of the yeast exopolysaccharides display some sort of biological activity. Some of them have already applications in chemistry, pharmacy, cosmetics or as probiotic. Furthermore, some yeast exopolysaccharides, such as pullulan, exhibit specific physico-chemical and rheological properties, making them useful in a wide range of technical applications. A survey is given here of the production, the characteristics and the application potential of currently well studied yeast extracellular polysaccharides.

  2. Insights into the Life Cycle of Yeasts from the CTG Clade Revealed by the Analysis of the Millerozyma (Pichia) farinosa Species Complex

    PubMed Central

    Jacques, Noémie; Leh-Louis, Véronique; Sacerdot, Christine; Casaregola, Serge

    2012-01-01

    Among ascomycetous yeasts, the CTG clade is so-called because its constituent species translate CTG as serine instead of leucine. Though the biology of certain pathogenic species such as Candida albicans has been much studied, little is known about the life cycles of non-pathogen species of the CTG clade. Taking advantage of the recently obtained sequence of the biotechnological Millerozyma (Pichiasorbitophila) farinosa strain CBS 7064, we used MLST to better define phylogenic relationships between most of the Millerozyma farinosa strains available in public collections. This led to the constitution of four phylogenetic clades diverging from 8% to 15% at the DNA level and possibly constituting a species complex (M. farinosa) and to the proposal of two new species:Millerozyma miso sp. nov. CBS 2004T ( = CLIB 1230T) and Candida pseudofarinosa sp. nov.NCYC 386T( = CLIB 1231T).Further analysis showed that M. farinosa isolates exist as haploid and inter-clade hybrids. Despite the sequence divergence between the clades, secondary contacts after reproductive isolation were evidenced, as revealed by both introgression and mitochondria transfer between clades. We also showed that the inter-clade hybrids do sporulate to generate mainly viable vegetative diploid spores that are not the result of meiosis, and very rarely aneuploid spores possibly through the loss of heterozygosity during sporulation. Taken together, these results show that in this part of the CTG clade, non-Mendelian genetic exchanges occur at high rates through hybridization between divergent strainsfrom distinct clades and subsequent massive loss of heterozygosity. This combination of mechanisms could constitute an alternative sexuality leading to an unsuspected biodiversity. PMID:22574125

  3. YEASTS FROM THE NORTH SEA AND AMOCO CADIZ OIL

    EPA Science Inventory

    The species and densities of yeasts isolated from North Sea waters before and after the production of oil were compared. Debaryomyces hansenii was the predominant species, but after oil production, Candida guillieromondii, a hydrocarbonoclastic yeast, was more commonly isolated a...

  4. Neonectria and Cylindrocarpon: the Nectria mammoidea group and species lacking microconidia.

    PubMed

    Brayford, David; Honda, Barry M; Mantiri, Feky R; Samuels, Gary J

    2004-01-01

    Neonectria (Hypocreales: Nectriaceae) species having Cylindrocarpon anamorphs that lack microconidia and chlamydospores include: Neo. discophora var. discophora, Neo. discophora var. rubi, stat nov. et comb. nov., Neo. lucida, comb. nov., Neo. viridispora, sp. nov. and Neo. westlandica, comb. nov. Perithecia of these species are red and perithecial anatomyis of the N. mammoidea type, with a palisade of hypha-like cells in the outer perithecial wall. These species occur on recently dead or dying trees. Perithecia of Neo. betulae, sp. nov and Neo. dumontii, sp. nov. are anatomically and biologically similar to those of Neo. discophora. The only known culture of Neo. betulae remained sterile, while Neo. dumontii has not been cultured; their anamorphs are presumed to be Cylindrocarpon. Analyses of mit ssu rDNA sequences indicate that Neonectria/Cylindrocarpon is monophyletic. Within the genus, species having N. mammoidea type perithecia are paraphyletic. Most species cluster with Neo. discophora, but Neo. westlandica and Neo. trachosa are basal to a clade that includes species that do not have a N. mammoidea-type perithecium. Nectria fuckeliana clusters independently of Neonectria and Nectria. Although reported to have a Cylindrocarpon anamorph, fresh ascospore isolates of N. fuckeliana did not produce Cylindrocarpon macroconidia but produced acremonium- or verticillium-like anamorphs. A key to nectriaceous species of Neonectria that have Cylindrocarpon anamorphs that lack microconidia and chlamydospores and/or that have a N. mammoidea type perithecial wall anatomy is presented. New combinations are proposed for other species formerly included in Nectria that have non-microconidial Cylindrocarpon anamorphs: Neonectria cinnamomea, Neo. jungneri, Neo. platycephala, Neo. phaeodisca and Neo. verrucospora. PMID:21148879

  5. New and emerging yeast pathogens.

    PubMed Central

    Hazen, K C

    1995-01-01

    The most common yeast species that act as agents of human disease are Candida albicans, Candida tropicalis, Candida glabrata, Candida parapsilosis, and Cryptococcus neoformans. The incidence of infections by other yeasts has increased during the past decade. The most evident emerging pathogens are Malassezia furfur, Trichosporon beigelii, Rhodotorula species, Hansenula anomala, Candida lusitaniae, and Candida krusei. Organisms once considered environmental contaminants or only industrially important, such as Candida utilis and Candida lipolytica, have now been implicated as agents of fungemia, onychomycosis, and systemic disease. The unusual yeasts primarily infect immunocompromised patients, newborns, and the elderly. The role of central venous catheter removal and antifungal therapy in patient management is controversial. The antibiograms of the unusual yeasts range from resistant to the most recent azoles and amphotericin B to highly susceptible to all antifungal agents. Current routine methods for yeast identification may be insufficient to identify the unusual yeasts within 2 days after isolation. The recognition of unusual yeasts as agents of sometimes life-threatening infection and their unpredictable antifungal susceptibilities increase the burden on the clinical mycology laboratory to pursue complete species identification and MIC determinations. Given the current and evolving medical practices for management of seriously ill patients, further evaluations of the clinically important data about these yeasts are needed. PMID:8665465

  6. Multigene Assessment of the Species Boundaries and Sexual Status of the Basidiomycetous Yeasts Cryptococcus flavescens and C. terrestris (Tremellales)

    PubMed Central

    Sharma, Lav; Carvalho, Cláudia; Fonseca, Álvaro

    2015-01-01

    Cryptococcus flavescens and C. terrestris are phenotypically indistinguishable sister species that belong to the order Tremellales (Tremellomycetes, Basidiomycota) and which may be mistaken for C. laurentii based on phenotype. Phylogenetic separation between C. flavescens and C. terrestris was based on rDNA sequence analyses, but very little is known on their intraspecific genetic variability or propensity for sexual reproduction. We studied 59 strains from different substrates and geographic locations, and used a multilocus sequencing (MLS) approach complemented with the sequencing of mating type (MAT) genes to assess genetic variation and reexamine the boundaries of the two species, as well as their sexual status. The following five loci were chosen for MLS: the rDNA ITS-LSU region, the rDNA IGS1 spacer, and fragments of the genes encoding the largest subunit of RNA polymerase II (RPB1), the translation elongation factor 1 alpha (TEF1) and the p21-activated protein kinase (STE20). Phylogenetic network analyses confirmed the genetic separation of the two species and revealed two additional cryptic species, for which the names Cryptococcus baii and C. ruineniae are proposed. Further analyses of the data revealed a high degree of genetic heterogeneity within C. flavescens as well as evidence for recombination between lineages detected for this species. Strains of C. terrestris displayed higher levels of similarity in all analysed genes and appear to make up a single recombining group. The two MAT genes (STE3 and SXI1/SXI2) sequenced for C. flavescens strains confirmed the potential for sexual reproduction and suggest the presence of a tetrapolar mating system with a biallelic pheromone/receptor locus and a multiallelic HD locus. In C. terrestris we could only sequence STE3, which revealed a biallelic P/R locus. In spite of the strong evidence for sexual recombination in the two species, attempts at mating compatible strains of both species on culture media were

  7. Molecular Characterization of Reptile Pathogens Currently Known as Members of the Chrysosporium Anamorph of Nannizziopsis vriesii Complex and Relationship with Some Human-Associated Isolates

    PubMed Central

    Hambleton, Sarah; Paré, Jean A.

    2013-01-01

    In recent years, the Chrysosporium anamorph of Nannizziopsis vriesii (CANV), Chrysosporium guarroi, Chrysosporium ophiodiicola, and Chrysosporium species have been reported as the causes of dermal or deep lesions in reptiles. These infections are contagious and often fatal and affect both captive and wild animals. Forty-nine CANV isolates from reptiles and six isolates from human sources were compared with N. vriesii based on their cultural characteristics and DNA sequence data. Analyses of the sequences of the internal transcribed spacer and small subunit of the nuclear ribosomal gene revealed that the reptile pathogens and human isolates belong in well-supported clades corresponding to three lineages that are distinct from all other taxa within the family Onygenaceae of the order Onygenales. One lineage represents the genus Nannizziopsis and comprises N. vriesii, N. guarroi, and six additional species encompassing isolates from chameleons and geckos, crocodiles, agamid and iguanid lizards, and humans. Two other lineages comprise the genus Ophidiomyces, with the species Ophidiomyces ophiodiicola occurring only in snakes, and Paranannizziopsis gen. nov., with three new species infecting squamates and tuataras. The newly described species are Nannizziopsis dermatitidis, Nannizziopsis crocodili, Nannizziopsis barbata, Nannizziopsis infrequens, Nannizziopsis hominis, Nannizziopsis obscura, Paranannizziopsis australasiensis, Paranannizziopsis californiensis, and Paranannizziopsis crustacea. Chrysosporium longisporum has been reclassified as Paranannizziopsis longispora. N. guarroi causes yellow fungus disease, a common infection in bearded dragons and green iguanas, and O. ophiodiicola is an emerging pathogen of captive and wild snakes. Human-associated species were not recovered from reptiles, and reptile-associated species were recovered only from reptiles, thereby mitigating concerns related to zoonosis. PMID:23926168

  8. Molecular characterization of reptile pathogens currently known as members of the chrysosporium anamorph of Nannizziopsis vriesii complex and relationship with some human-associated isolates.

    PubMed

    Sigler, Lynne; Hambleton, Sarah; Paré, Jean A

    2013-10-01

    In recent years, the Chrysosporium anamorph of Nannizziopsis vriesii (CANV), Chrysosporium guarroi, Chrysosporium ophiodiicola, and Chrysosporium species have been reported as the causes of dermal or deep lesions in reptiles. These infections are contagious and often fatal and affect both captive and wild animals. Forty-nine CANV isolates from reptiles and six isolates from human sources were compared with N. vriesii based on their cultural characteristics and DNA sequence data. Analyses of the sequences of the internal transcribed spacer and small subunit of the nuclear ribosomal gene revealed that the reptile pathogens and human isolates belong in well-supported clades corresponding to three lineages that are distinct from all other taxa within the family Onygenaceae of the order Onygenales. One lineage represents the genus Nannizziopsis and comprises N. vriesii, N. guarroi, and six additional species encompassing isolates from chameleons and geckos, crocodiles, agamid and iguanid lizards, and humans. Two other lineages comprise the genus Ophidiomyces, with the species Ophidiomyces ophiodiicola occurring only in snakes, and Paranannizziopsis gen. nov., with three new species infecting squamates and tuataras. The newly described species are Nannizziopsis dermatitidis, Nannizziopsis crocodili, Nannizziopsis barbata, Nannizziopsis infrequens, Nannizziopsis hominis, Nannizziopsis obscura, Paranannizziopsis australasiensis, Paranannizziopsis californiensis, and Paranannizziopsis crustacea. Chrysosporium longisporum has been reclassified as Paranannizziopsis longispora. N. guarroi causes yellow fungus disease, a common infection in bearded dragons and green iguanas, and O. ophiodiicola is an emerging pathogen of captive and wild snakes. Human-associated species were not recovered from reptiles, and reptile-associated species were recovered only from reptiles, thereby mitigating concerns related to zoonosis. PMID:23926168

  9. Comparison of the processes involved in reduction by the substrate for two homologous flavocytochromes b2 from different species of yeast.

    PubMed Central

    Capeillère-Blandin, C; Barber, M J; Bray, R C

    1986-01-01

    A detailed study of the electron exchanges involved between FMN and haem b2 groups within flavocytochrome b2 of yeast Hansenula anomala (H-enzyme) was performed. The results were compared with those for the homologous enzyme of yeast Saccharomyces cerevisiae (Sx-enzyme) re-investigated at 5 degrees C. The mid-point reduction potentials of FMN and haem were determined by two complementary methods: potentiometric titration with substrate, L-lactate, in the presence of dye mediators with quantification of the reduced species performed by spectrophotometry at suitable wavelengths; anaerobic titration of the enzyme by its substrate by monitoring the e.p.r. signals of the semiquinone and Fe3+ species. Values of Em,7 = -19, -23 and -45 V were determined respectively from the data for the three redox systems Ho/Hr, Fo/Fsq and Fsq/Fr in the H-enzyme instead of +6, -44 and -57 mV respectively in the Sx-enzyme [Capeillère-Blandin, Bray, Iwatsubo & Labeyrie (1975) Eur. J. Biochem. 54, 549-566]. Parallel e.p.r rapid-freezing and absorbance stopped-flow studies allowed determination of the time courses of the various redox species during their reduction by L-lactate. The flavin and the haem reduction time courses were biphasic. In the initial fast phase the reduction of flavin monitored by absorbance measurements is accomplished with a rate constant kF = 360 s-1. The reduction of the haem lags the reduction of flavin with a rate constant kH = 170 s-1. The appearance of flavin free radical is slower than the reduction in flavin absorbance and occurs with a rate constant close to that of the reduction of the haem. At saturating L-lactate concentration the initial rapid phase (up to 15 ms) involved in the overall turnover can be adequately simulated with a two-step reaction scheme. The main difference between the enzymes lies especially at the level of the first step of electron exchange between bound lactate and flavin, which for the H-enzyme is no longer the rate-limiting step

  10. Molecular and Genetic Evidence for a Tetrapolar Mating System in the Basidiomycetous Yeast Kwoniella mangrovensis and Two Novel Sibling Species

    PubMed Central

    Guerreiro, Marco A.; Springer, Deborah J.; Rodrigues, Joana A.; Rusche, Laura N.; Findley, Keisha; Heitman, Joseph

    2013-01-01

    Kwoniella mangrovensis has been described as a sexual species with a bipolar mating system. Phylogenetic analysis of multiple genes places this species together with Kwoniella heveanensis in the Kwoniella clade, a sister clade to that containing two pathogenic species of global importance, Cryptococcus neoformans and Cryptococcus gattii, within the Tremellales. Recent studies defining the mating type loci (MAT) of species in these clades showed that, with the exception of C. neoformans and C. gattii, which are bipolar with a single biallelic multigene MAT locus, several other species feature a tetrapolar mating system with two unlinked loci (homeodomain [HD] and pheromone/receptor [P/R] loci). We characterized several strains from the original study describing K. mangrovensis; two MAT regions were amplified and sequenced: the STE20 gene (P/R locus) and the divergently transcribed SXI1 and SXI2 genes (HD locus). We identified five different mating types with different STE20/SXI allele combinations that together with results of mating experiments demonstrate that K. mangrovensis is not bipolar but instead has a tetrapolar mating system. Sequence and gene analysis for a 43-kb segment of the K. mangrovensis type strain MAT locus revealed remarkable synteny with the homologous K. heveanensis MAT P/R region, providing new insights into slower evolution of MAT loci in the Kwoniella compared to the Cryptococcus clade of the Tremellales. The study of additional isolates from plant substrates in Europe and Botswana using a combination of multilocus sequencing with MAT gene analysis revealed two novel sibling species that we name Kwoniella europaea and Kwoniella botswanensis and which appear to also have tetrapolar mating systems. PMID:23524993

  11. Onychomycosis caused by Scytalidium dimidiatum. Report of two cases. Review of the taxonomy of the synanamorph and anamorph forms of this coelomycete.

    PubMed

    Lacaz, C S; Pereira, A D; Heins-Vaccari, E M; Cucé, L C; Benatti, C; Nunes, R S; de Melo, N T; de Freitas-Leite, R S; Hernández-Arriagada, G L

    1999-01-01

    The authors report two cases of onychomycosis in the dystrophic form, one of them involving an HIV-positive patient, provoked by Scytalidium dimidiatum, previously called Scytalidium lignicola. The subject is reviewed from the taxonomic viewpoint, considering the anamorph Hendersonula toruloidea as a synonym of Nattrassia mangiferae, and having Scytalidium dimidiatum as the major synanamorph. According to many mycologists, Scytalidium hyalinum may be a separate species or a hyaline mutant of Scytalidium dimidiatum. Scytalidium lignicola Pesante 1957 was considered to be the type-species of the genus by ELLIS (1971)13 and later to be a "conidial state" of Hendersonula toruloidea by the same author, today known as Nattrassia mangiferae. The microorganism lives only on the roots of certain plants (mainly Platanus and Pinus). It produces pycnidia and is not considered to be a pathogen, although it is considered as a possible emerging agent capable of provoking opportunistic fungal lesions. The importance of this topic as one of the most outstanding in fungal taxonomy, so likely to be modified over time, as well as its interest in the field of dermatologic mycology, are emphasized. PMID:10602547

  12. Lager Yeast Comes of Age

    PubMed Central

    2014-01-01

    Alcoholic fermentations have accompanied human civilizations throughout our history. Lager yeasts have a several-century-long tradition of providing fresh beer with clean taste. The yeast strains used for lager beer fermentation have long been recognized as hybrids between two Saccharomyces species. We summarize the initial findings on this hybrid nature, the genomics/transcriptomics of lager yeasts, and established targets of strain improvements. Next-generation sequencing has provided fast access to yeast genomes. Its use in population genomics has uncovered many more hybridization events within Saccharomyces species, so that lager yeast hybrids are no longer the exception from the rule. These findings have led us to propose network evolution within Saccharomyces species. This “web of life” recognizes the ability of closely related species to exchange DNA and thus drain from a combined gene pool rather than be limited to a gene pool restricted by speciation. Within the domesticated lager yeasts, two groups, the Saaz and Frohberg groups, can be distinguished based on fermentation characteristics. Recent evidence suggests that these groups share an evolutionary history. We thus propose to refer to the Saaz group as Saccharomyces carlsbergensis and to the Frohberg group as Saccharomyces pastorianus based on their distinct genomes. New insight into the hybrid nature of lager yeast will provide novel directions for future strain improvement. PMID:25084862

  13. Taxonomy and Phylogeny of the Fusarium dimerum Species Group

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The morphospecies Fusarium dimerum, known only from its anamorph, comprises at least 12 phylogenetically distinct species. Analyses of the large subunit ribosomal DNA (LSU rDNA) show they are taxa of the Nectriaceae (Hypocreales) and form a phylogenetically distinct clade within Fusarium. Accordin...

  14. Nomenclatural realignment of Neotyphodium species with genus Epichloe

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Nomenclatural rule changes in the International Code of Nomenclature for algae, fungi and plants made at the 18th International Botanical Congress in Melbourne, Australia in 2011 require that a single name is used for all fungi. Since the anamorphic stages of Epichloë species have been classified i...

  15. Observations on Neobarya, including new species and new combinations

    Technology Transfer Automated Retrieval System (TEKTRAN)

    New combinations and new species are proposed in Neobarya: N. aurantiaca comb. nov., N. byssicola comb. nov., N. lichenicola comb. nov., N. lutea sp. nov., N. peltigerae sp. nov., N. xylariicola sp. nov. Neobarya agaricicola, and N. parasitica are redescribed. Anamorphs associated with N. agaricico...

  16. Strain typing of Zygosaccharomyces yeast species using a single molecular method based on polymorphism of the intergenic spacer region (IGS).

    PubMed

    Wrent, Petra; Rivas, Eva-María; Peinado, José M; de Silóniz, María-Isabel

    2010-08-15

    Unlike previously reported methods that need a combination of several typing techniques, we have developed a single method for strain typing of the Zygosaccharomyces bailii, Z. mellis and Z. rouxii spoilage species. Strains belonging to other species have also been included for comparison. We have demonstrated that the IGS-PCR RFLP method has a high discriminative power. Considering the three endonucleases used in this work, we have obtained a variability of 100% for Z. mellis and Z. rouxii strains and up to 70% for Z. bailii. We have also detected two misidentified Z. mellis strains (CBS 711 and CBS 7412) which have RFLP patterns with a set of bands characteristic of Z. rouxii strains. Sequencing of 26S rDNA D1/D2 domains and the 5.8-ITS rDNA region confirmed these strains as Z. rouxii. The method also groups three certified hybrid strains of Zygosaccharomyces in a separate cluster. PMID:20619910

  17. The Production of Reactive Oxygen Species Is a Universal Action Mechanism of Amphotericin B against Pathogenic Yeasts and Contributes to the Fungicidal Effect of This Drug

    PubMed Central

    Mesa-Arango, Ana Cecilia; Trevijano-Contador, Nuria; Román, Elvira; Sánchez-Fresneda, Ruth; Casas, Celia; Herrero, Enrique; Argüelles, Juan Carlos; Pla, Jesús; Cuenca-Estrella, Manuel

    2014-01-01

    Amphotericin B (AMB) is an antifungal drug that binds to ergosterol and forms pores at the cell membrane, causing the loss of ions. In addition, AMB induces the accumulation of reactive oxygen species (ROS), and although these molecules have multiple deleterious effects on fungal cells, their specific role in the action mechanism of AMB remains unknown. In this work, we studied the role of ROS in the action mechanism of AMB. We determined the intracellular induction of ROS in 44 isolates of different pathogenic yeast species (Candida albicans, Candida parapsilosis, Candida glabrata, Candida tropicalis, Candida krusei, Cryptococcus neoformans, and Cryptococcus gattii). We also characterized the production of ROS in AMB-resistant isolates. We found that AMB induces the formation of ROS in all the species tested. The inhibition of the mitochondrial respiratory chain by rotenone blocked the induction of ROS by AMB and provided protection from the killing action of the antifungal. Moreover, this phenomenon was absent in strains that displayed resistance to AMB. These strains showed an alteration in the respiration rate and mitochondrial membrane potential and also had higher catalase activity than that of the AMB-susceptible strains. Consistently, AMB failed to induce protein carbonylation in the resistant strains. Our data demonstrate that the production of ROS by AMB is a universal and important action mechanism that is correlated with the fungicidal effect and might explain the low rate of resistance to the molecule. Finally, these data provide an opportunity to design new strategies to improve the efficacy of this antifungal. PMID:25155595

  18. The production of reactive oxygen species is a universal action mechanism of Amphotericin B against pathogenic yeasts and contributes to the fungicidal effect of this drug.

    PubMed

    Mesa-Arango, Ana Cecilia; Trevijano-Contador, Nuria; Román, Elvira; Sánchez-Fresneda, Ruth; Casas, Celia; Herrero, Enrique; Argüelles, Juan Carlos; Pla, Jesús; Cuenca-Estrella, Manuel; Zaragoza, Oscar

    2014-11-01

    Amphotericin B (AMB) is an antifungal drug that binds to ergosterol and forms pores at the cell membrane, causing the loss of ions. In addition, AMB induces the accumulation of reactive oxygen species (ROS), and although these molecules have multiple deleterious effects on fungal cells, their specific role in the action mechanism of AMB remains unknown. In this work, we studied the role of ROS in the action mechanism of AMB. We determined the intracellular induction of ROS in 44 isolates of different pathogenic yeast species (Candida albicans, Candida parapsilosis, Candida glabrata, Candida tropicalis, Candida krusei, Cryptococcus neoformans, and Cryptococcus gattii). We also characterized the production of ROS in AMB-resistant isolates. We found that AMB induces the formation of ROS in all the species tested. The inhibition of the mitochondrial respiratory chain by rotenone blocked the induction of ROS by AMB and provided protection from the killing action of the antifungal. Moreover, this phenomenon was absent in strains that displayed resistance to AMB. These strains showed an alteration in the respiration rate and mitochondrial membrane potential and also had higher catalase activity than that of the AMB-susceptible strains. Consistently, AMB failed to induce protein carbonylation in the resistant strains. Our data demonstrate that the production of ROS by AMB is a universal and important action mechanism that is correlated with the fungicidal effect and might explain the low rate of resistance to the molecule. Finally, these data provide an opportunity to design new strategies to improve the efficacy of this antifungal. PMID:25155595

  19. Counting Yeast.

    ERIC Educational Resources Information Center

    Bealer, Jonathan; Welton, Briana

    1998-01-01

    Describes changes to a traditional study of population in yeast colonies. Changes to the procedures include: (1) only one culture per student team; (2) cultures are inoculated only once; and (3) the same tube is sampled daily. (DDR)

  20. Ghost reflections of Gaussian beams in anamorphic optical systems with an application to Michelson interferometer.

    PubMed

    Abd El-Maksoud, Rania H

    2016-02-20

    In this paper, a methodology is developed to model and analyze the effect of undesired (ghost) reflections of Gaussian beams that are produced by anamorphic optical systems. The superposition of these beams with the nominal beam modulates the nominal power distribution at the recording plane. This modulation may cause contrast reduction, veiling parts of the nominal image, and/or the formation of spurious interference fringes. The developed methodology is based on synthesizing the beam optical paths into nominal and ghost optical beam paths. Similar to the nominal beam, we present the concept that each ghost beam is characterized by a beam size, wavefront radius of curvature, and Gouy phase in the paraxial regime. The nominal and ghost beams are sequentially traced through the system and formulas for estimating the electric field magnitude and phase of each ghost beam at the recording plane are presented. The effective electric field is the addition of the individual nominal and ghost electric fields. Formulas for estimating Gouy phase, the shape of the interference fringes, and the central interference order are introduced. As an application, the theory of the formation of the interference fringes by Michelson interferometer is presented. This theory takes into consideration the ghost reflections that are formed by the beam splitter. To illustrate the theory and to show its wide applicability, simulation examples that include a Mangin mirror, a Michelson interferometer, and a black box optical system are provided. PMID:26906582

  1. Implications of Planck2015 for inflationary, ekpyrotic and anamorphic bouncing cosmologies

    NASA Astrophysics Data System (ADS)

    Ijjas, Anna; Steinhardt, Paul J.

    2016-02-01

    The results from Planck2015, when combined with earlier observations from the Wilkinson Microwave Anisotropy Probe, Atacama Cosmology Telescope, South Pole Telescope and other experiments, were the first observations to disfavor the ‘classic’ inflationary paradigm. To satisfy the observational constraints, inflationary theorists have been forced to consider plateau-like inflaton potentials that introduce more parameters and more fine-tuning, problematic initial conditions, multiverse-unpredictability issues, and a new ‘unlikeliness problem’. Some propose turning instead to a ‘postmodern’ inflationary paradigm in which the cosmological properties in our observable Universe are only locally valid and set randomly, with completely different properties (and perhaps even different physical laws) existing in most regions outside our horizon. By contrast, the new results are consistent with the simplest versions of ekpyrotic cyclic models in which the Universe is smoothed and flattened during a period of slow contraction followed by a bounce, and another promising bouncing theory, anamorphic cosmology, has been proposed that can produce distinctive predictions.

  2. NOX4 in Mitochondria: Yeast Two-Hybrid-Based Interaction with Complex I Without Relevance for Basal Reactive Oxygen Species?

    PubMed Central

    Hirschhäuser, Christine; Bornbaum, Julia; Reis, Anna; Böhme, Sabrina; Kaludercic, Nina; Menabò, Roberta; Di Lisa, Fabio; Boengler, Kerstin; Shah, Ajay M.

    2015-01-01

    Abstract NADPH oxidases (NOXs) represent the only known dedicated source of reactive oxygen species (ROS) and thus a prime therapeutic target. Type 4 NOX is unique as it produces H2O2, is constitutively active, and has been suggested to localize to cardiac mitochondria, thus possibly linking mitochondrial and NOX-derived ROS formation. The aim of this study was to identify NOX4-binding proteins and examine the possible physiological localization of NOX4 to mitochondria and its impact on mitochondrial ROS formation. We here provide evidence that NOX4 can, in principle, enter protein–protein interactions with mitochondrial complex I NADH dehydrogenase subunits, 1 and 4L. However, under physiological conditions, NOX4 protein was neither detectable in the kidney nor in cardiomyocyte mitochondria. The NOX inhibitor, GKT136901, slightly reduced ROS formation in cardiomyocyte mitochondria, but this effect was observed in both wild-type and Nox4−/− mice. NOX4 may thus associate with mitochondrial complex I proteins, but in cardiac and renal mitochondria under basal conditions, expression is beyond our detection limits and does not contribute to ROS formation. Antioxid. Redox Signal. 23, 1106–1112. PMID:26237157

  3. Drosophila Regulate Yeast Density and Increase Yeast Community Similarity in a Natural Substrate

    PubMed Central

    Stamps, Judy A.; Yang, Louie H.; Morales, Vanessa M.; Boundy-Mills, Kyria L.

    2012-01-01

    Drosophila melanogaster adults and larvae, but especially larvae, had profound effects on the densities and community structure of yeasts that developed in banana fruits. Pieces of fruit exposed to adult female flies previously fed fly-conditioned bananas developed higher yeast densities than pieces of the same fruits that were not exposed to flies, supporting previous suggestions that adult Drosophila vector yeasts to new substrates. However, larvae alone had dramatic effects on yeast density and species composition. When yeast densities were compared in pieces of the same fruits assigned to different treatments, fruits that developed low yeast densities in the absence of flies developed significantly higher yeast densities when exposed to larvae. Across all of the fruits, larvae regulated yeast densities within narrow limits, as compared to a much wider range of yeast densities that developed in pieces of the same fruits not exposed to flies. Larvae also affected yeast species composition, dramatically reducing species diversity across fruits, reducing variation in yeast communities from one fruit to the next (beta diversity), and encouraging the consistent development of a yeast community composed of three species of yeast (Candida californica, C. zemplinina, and Pichia kluvyeri), all of which were palatable to larvae. Larvae excreted viable cells of these three yeast species in their fecal pools, and discouraged the growth of filamentous fungi, processes which may have contributed to their effects on the yeast communities in banana fruits. These and other findings suggest that D. melanogaster adults and their larval offspring together engage in ‘niche construction’, facilitating a predictable microbial environment in the fruit substrates in which the larvae live and develop. PMID:22860093

  4. Yeasts in floral nectar: a quantitative survey

    PubMed Central

    Herrera, Carlos M.; de Vega, Clara; Canto, Azucena; Pozo, María I.

    2009-01-01

    Background and Aims One peculiarity of floral nectar that remains relatively unexplored from an ecological perspective is its role as a natural habitat for micro-organisms. This study assesses the frequency of occurrence and abundance of yeast cells in floral nectar of insect-pollinated plants from three contrasting plant communities on two continents. Possible correlations between interspecific differences in yeast incidence and pollinator composition are also explored. Methods The study was conducted at three widely separated areas, two in the Iberian Peninsula (Spain) and one in the Yucatán Peninsula (Mexico). Floral nectar samples from 130 species (37–63 species per region) in 44 families were examined microscopically for the presence of yeast cells. For one of the Spanish sites, the relationship across species between incidence of yeasts in nectar and the proportion of flowers visited by each of five major pollinator categories was also investigated. Key Results Yeasts occurred regularly in the floral nectar of many species, where they sometimes reached extraordinary densities (up to 4 × 105 cells mm−3). Depending on the region, between 32 and 44 % of all nectar samples contained yeasts. Yeast cell densities in the order of 104 cells mm−3 were commonplace, and densities >105 cells mm−3 were not rare. About one-fifth of species at each site had mean yeast cell densities >104 cells mm−3. Across species, yeast frequency and abundance were directly correlated with the proportion of floral visits by bumble-bees, and inversely with the proportion of visits by solitary bees. Conclusions Incorporating nectar yeasts into the scenario of plant–pollinator interactions opens up a number of intriguing avenues for research. In addition, with yeasts being as ubiquitous and abundant in floral nectars as revealed by this study, and given their astounding metabolic versatility, studies focusing on nectar chemical features should carefully control for the presence

  5. Yeast Droplets

    NASA Astrophysics Data System (ADS)

    Nguyen, Baochi; Upadhyaya, Arpita; van Oudenaarden, Alexander; Brenner, Michael

    2002-11-01

    It is well known that the Young's law and surface tension govern the shape of liquid droplets on solid surfaces. Here we address through experiments and theory the shape of growing aggregates of yeast on agar substrates, and assess whether these ideas still hold. Experiments are carried out on Baker's yeast, with different levels of expressions of an adhesive protein governing cell-cell and cell-substrate adhesion. Changing either the agar concentration or the expression of this protein modifies the local contact angle of a yeast droplet. When the colony is small, the shape is a spherical cap with the contact angle obeying Young's law. However, above a critical volume this structure is unstable, and the droplet becomes nonspherical. We present a theoretical model where this instability is caused by bulk elastic effects. The model predicts that the transition depends on both volume and contact angle, in a manner quantitatively consistent with our experiments.

  6. Mycotoxins - prevention and decontamination by yeasts.

    PubMed

    Pfliegler, Walter P; Pusztahelyi, Tünde; Pócsi, István

    2015-07-01

    The application of yeasts has great potential in reducing the economic damage caused by toxigenic fungi in the agriculture. Some yeasts may act as biocontrol agents inhibiting the growth of filamentous fungi. These species may also gain importance in the preservation of agricultural products and in the reduction of their mycotoxin contamination, yet the extent of mycotoxin production in the presence of biocontrol agents is relatively less understood. The application of yeasts in various technological processes may have a direct inhibitory effect on the toxin production of certain molds, which is independent of their growth suppressing effect. Furthermore, several yeast species are capable of accumulating mycotoxins from agricultural products, thereby effectively decontaminating them. Probiotic yeasts or products containing yeast cell wall are also applied to counteract mycotoxicosis in livestock. Several yeast strains are also able to degrade toxins to less-toxic or even non-toxic substances. This intensively researched field would greatly benefit from a deeper knowledge on the genetic and molecular basis of toxin degradation. Moreover, yeasts and their biotechnologically important enzymes may exhibit sensitivity to certain mycotoxins, thereby mounting a considerable problem for the biotechnological industry. It is noted that yeasts are generally regarded as safe; however, there are reports of toxin degrading species that may cause human fungal infections. The aspects of yeast-mycotoxin relations with a brief consideration of strain improvement strategies and genetic modification for improved detoxifying properties and/or mycotoxin resistance are reviewed here. PMID:25682759

  7. Evaluation of the Uni-Yeast-Tek kit for the identification of medically important yeasts.

    PubMed Central

    Bowman, P I; Ahearn, D G

    1975-01-01

    The Uni-Yeast-Tek system, a commercially prepared kit and scheme for the rapid identification of medically important yeasts (Corning Medical), was evaluated in comparison with a conventional procedure in the identification of 623 yeasts. The system permitted the presumptive identification of 99.8% of 436 isolates representing 16 common species commonly isolated in the clinical laboratory. Correct biochemical and morphological analyses were obtained with 48 other species, but their specific identification required additional data. Images PMID:1102563

  8. Tropical species of Cladobotryum and Hypomyces producing red pigments

    PubMed Central

    Põldmaa, Kadri

    2011-01-01

    Twelve species of Hypomyces/Cladobotryum producing red pigments are reported growing in various tropical areas of the world. Ten of these are described as new, including teleomorphs for two previously known anamorphic species. In two species the teleomorph has been found in nature and in three others it was obtained in culture; only anamorphs are known for the rest. None of the studied tropical collections belongs to the common temperate species H. rosellus and H. odoratus to which the tropical teleomorphic collections had previously been assigned. Instead, taxa encountered in the tropics are genetically and morphologically distinct from the nine species of Hypomyces/Cladobotryum producing red pigments known from temperate regions. Besides observed host preferences, anamorphs of several species can spread fast on soft ephemeral agaricoid basidiomata but the slower developing teleomorphs are mostly found on polyporoid basidiomata or bark. While a majority of previous records from the tropics involve collections from Central America, this paper also reports the diversity of these fungi in the Paleotropics. Africa appears to hold a variety of taxa as five of the new species include material collected in scattered localities of this mostly unexplored continent. In examining distribution patterns, most of the taxa do not appear to be pantropical. Some species are known only from the Western Hemisphere, while others have a geographic range from southeastern Asia to Africa or Australia. The use of various morphological characters of anamorphs and teleomorphs as well as culture characteristics in species delimitation is evaluated. For detecting genetic segregation, partial sequences of the two largest subunits of the ribosomal polymerase perform the best in terms of providing informative sites and the number of well-supported groups recognised in the phylogenies. These are followed by the sequence data of the translation-elongation factor 1-alpha, while the ribosomal DNA

  9. Evaluation of the Viabilities and Stabilities of Pathogenic Mold and Yeast Species Using Three Different Preservation Methods Over a 12-Year Period Along with a Review of Published Reports.

    PubMed

    Karabıçak, Nilgün; Karatuna, Onur; Akyar, Işın

    2016-06-01

    Serious mycological work requires a reliable source of cultures that are maintained under safe long-term storage. In this study, 1186 clinical fungal isolates consisting of molds (20 species in 11 genera) and yeasts (21 species in seven genera) maintained in water, under mineral oil at room temperature and cryopreserved at -80 °C for periods ranging from 1 to 12 years, were evaluated for their viabilities and stabilities. The strains were subcultured onto either Sabouraud dextrose agar or potato dextrose agar to determine the viabilities and purities. The stabilities of the dermatophytes were investigated using urease test medium, the Trichophyton agar test and morphological examination. The stabilities of yeasts were evaluated by microscopic morphology and by determining the antifungal susceptibilities of random samples of yeasts (n = 120). Additionally, 365 strains (dermatophytes, n = 115; yeasts, n = 250) were further characterized by "matrix-assisted laser desorption/ionization time-of-flight mass spectrometry." After 12 years of preservation, the survival rates with the three different preservation techniques, i.e., in water, under mineral oil and by freezing, were assessed as 94.7, 82.0 and 97.4 %, respectively. Viability was generally unrelated to the duration of storage. More stable and consistent growth was achieved after storage in water and freezing compared with mineral oil preservation. Our results demonstrate that the procedure for maintaining fungal cultures in water is a simple and inexpensive method, next to cryopreservation, and that both can be reliably used for the long-term preservation of most fungal isolates. PMID:26864747

  10. The Yeast Sphingolipid Signaling Landscape

    PubMed Central

    Montefusco, David J.; Matmati, Nabil

    2014-01-01

    Sphingolipids are recognized as signaling mediators in a growing number of pathways, and represent potential targets to address many diseases. The study of sphingolipid signaling in yeast has created a number of breakthroughs in the field, and has the potential to lead future advances. The aim of this article is to provide an inclusive view of two major frontiers in yeast sphingolipid signaling. In the first section, several key studies in the field of sphingolipidomics are consolidated to create a yeast sphingolipidome that ranks nearly all known sphingolipid species by their level in a resting yeast cell. The second section presents an overview of most known phenotypes identified for sphingolipid gene mutants, presented with the intention of illuminating not yet discovered connections outside and inside of the field. PMID:24220500

  11. [Yeast Communities of Formica aquilonia Colonies].

    PubMed

    Maksimova, A; Glushakova, A M; Kachalkin, A V; Chernov, I Yu; Panteleeva, S N; Reznikova, Zh I

    2016-01-01

    Yeast abundance and species diversity in the colonies of Formica aquilonia ants in birch-pine forbs forest, Novosibirsk oblast, Russia, was studied. The average yeast number in the anthill material was 10³-10⁴CFU/g, reaching 10⁵ CFU/g in the hatching chambers. Typical litter species (Trichosporon monilfiforme and Cystofilobasidium capitatum) were predominant in soil and litter around the anthills. Apart from these species, ascomycete species of the family Debaryomycetaceae, Debaryomyces hansenii and Schwanniomyces vanrijiae, were predominant in the anthill material. Yeast population of the ants consisted exclusively of the members of these two species. Thus, highly specific yeast communities formed in the colonies of Formica aquilonia ants differ from the communities of surrounding soil. These differences are an instance of environment-forming activity of the ants. PMID:27301134

  12. Selective media for detecting and enumerating foodborne yeasts.

    PubMed

    Beuchat, L R

    1993-06-25

    No one medium is satisfactory for detecting, isolating and enumerating all yeasts in all foods. Antibiotic-supplemented media such as dichloran rose Bengal chloramphenicol agar, tryptone glucose yeast extract chloramphenicol agar, oxytetracycline glucose yeast extract agar and rose Bengal chloramphenicol agar are superior to acidified potato dextrose agar and other acidified media for enumeration of the vast majority of spoilage yeasts. Dichloran glycerol (18%) agar performs well for enumerating moderately xerotolerant yeasts. Malt extract yeast extract glucose (up to 60%) can be used for detecting and enumerating moderate and extreme xerophiles. These media also support the growth of moulds. Lysine agar, Schwarz differential agar and Lin's wild yeast differential agar are used by the brewing industry to differentiate wild yeasts from brewer's strains. Lysine agar is selective for apiculate yeasts and ethanol sulfite yeast extract agar is selective for Saccharomyces. Both have application in wineries. Modified molybdate agar can be used to selectively isolate yeasts from tropical fruits. Preservative-resistant yeasts can be detected on malt acetic agar. The recommended incubation temperature is 25 degrees C, but incubation time between plating and counting colonies ranges from 5 days for determination of general populations of yeasts to 10 days for more for xerotolerant yeasts. There is need for new and improved media for selectively isolating various groups, genera, species and strains of yeasts capable of growing only under specific environmental conditions in specific types of foods and beverages. PMID:8357752

  13. European species of Hypocrea Part I. The green-spored species

    PubMed Central

    Jaklitsch, Walter M.

    2009-01-01

    At present 75 species of Hypocrea have been identified in temperate Europe. Nineteen green-spored species and their Trichoderma asexual states are here described in detail. Extensive searches for Hypocrea teleomorphs in 14 European countries, with emphasis on Central Europe, yielded more than 620 specimens within five years. The morphology of fresh and dry stromata was studied. In addition, available types of species described from Europe were examined. Cultures were prepared from ascospores and used to study the morphology of cultures and anamorphs, to determine growth rates, and to extract DNA that was used for amplification and sequencing of three genetic markers. ITS was used for identification, while RNA polymerase II subunit b (rpb2) and translation elongation factor 1 alpha (tef1) were analyzed for phylogenetic reconstruction of the genus. Several unexpected findings resulted from this project: 1) The previous view that only a small number of Trichoderma species form a teleomorph is erroneous. 2) All expectations concerning the number of species in Europe are by far exceeded. Seventy-five species of Hypocrea, two species of Protocrea, and Arachnocrea stipata, are herein identified in temperate Europe, based on the ITS identification routine using fresh material, on species described earlier without molecular data and on species recently described but not collected during this project. 3) Current data suggest that the biodiversity of Hypocrea / Trichoderma above soil exceeds the number of species isolated from soil. 4) The number of Trichoderma species forming hyaline conidia has been considered a small fraction. In Europe, 26 species of those forming teleomorphs produce hyaline conidia, while 42 green-conidial species are known. Three of the detected Hypocrea species do not form an anamorph in culture, while the anamorph is unknown in four species, because they have never been cultured. This work is a preliminary account of Hypocrea and their Trichoderma

  14. Biotechnological Applications of Dimorphic Yeasts

    NASA Astrophysics Data System (ADS)

    Doiphode, N.; Joshi, C.; Ghormade, V.; Deshpande, M. V.

    The dimorphic yeasts have the equilibrium between spherical growth (budding) and polarized (hyphal or pseudohyphal tip elongation) which can be triggered by change in the environmental conditions. The reversible growth phenomenon has made dimorphic yeasts as an useful model to understand fungal evolution and fungal differentiation, in general. In nature dimorphism is clearly evident in plant and animal fungal pathogens, which survive and most importantly proliferate in the respective hosts. However, number of organisms with no known pathogenic behaviour also show such a transition, which can be exploited for the technological applications due to their different biochemical make up under different morphologies. For instance, chitin and chitosan production using dimorphic Saccharomyces, Mucor, Rhizopus and Benjaminiella, oil degradation and biotransformation with yeast-form of Yarrowia species, bioremediation of organic pollutants, exopolysac-charide production by yeast-phase of Aureobasidium pullulans, to name a few. Myrothecium verrucaria can be used for seed dressing in its yeast form and it produces a mycolytic enzyme complex in its hyphal-form for the biocontrol of fungal pathogens, while Beauveria bassiana and other entomopathogens kill the insect pest by producing yeast- like cells in the insect body. The form-specific expression of protease, chitinase, lipase, ornithine decarboxylase, glutamate dehydrogenases, etc. make Benjaminiella poitrasii, Basidiobolus sp., and Mucor rouxii strains important in bioremediation, nanobiotechnology, fungal evolution and other areas.

  15. Yeast community survey in the Tagus estuary.

    PubMed

    de Almeida, João M G C F

    2005-07-01

    The yeast community in the waters of the Tagus estuary, Portugal, was followed for over a year in order to assess its dynamics. Yeast occurrence and incidence were measured and this information was related to relevant environmental data. Yeast occurrence did not seem to depend upon tides, but river discharge had a dramatic impact both on the density and diversity of the community. The occurrence of some yeasts was partially correlated with faecal pollution indicators. Yeast isolates were characterized by microsatellite primed PCR (MSP-PCR) fingerprinting and rRNA gene sequencing. The principal species found were Candida catenulata, C. intermedia, C. parapsilosis, Clavispora lusitaniae, Debaryomyces hansenii, Pichia guilliermondii, Rhodotorula mucilaginosa and Rhodosporidium diobovatum. The incidence of these species was evaluated against the environmental context of the samples and the current knowledge about the substrates from which they are usually isolated. PMID:16329949

  16. Anthraquinone dyes decolorization capacity of anamorphic Bjerkandera adusta CCBAS 930 strain and its HRP-like negative mutants.

    PubMed

    Korniłłowicz-Kowalska, Teresa; Rybczyńska, Kamila

    2014-06-01

    Cultures of the anamorphic fungus Bjerkandera adusta CCBAS 930 decolorizing, in stationary cultures, 0.01 % solutions of carminic acid and Poly R-478, were characterised by a strong increase in the activity of the horseradish peroxidase (HRP-like) and manganese-dependent peroxidase (MnP) at a low activity of lignin peroxidase. Genotypically modified mutants of B. adusta CCBAS 930: 930-5 and 930-14, with total or partial loss of decolorization capabilities relative to anthraquinonic dyes, showed inhibition of the activity of HRP-like peroxidase and MnP. Whereas, compared to the parental strain, in the mutant cultures there was an increase in the activity of lignin peroxidase and laccase. The paper presents a discussion of the role of the studied enzymatic activities in the process of decolorization of anthraquinonic dyes by the strain B. adusta CCBAS 930. PMID:24415463

  17. Vertical viewing angle enhancement for the 360  degree integral-floating display using an anamorphic optic system.

    PubMed

    Erdenebat, Munkh-Uchral; Kwon, Ki-Chul; Yoo, Kwan-Hee; Baasantseren, Ganbat; Park, Jae-Hyeung; Kim, Eun-Soo; Kim, Nam

    2014-04-15

    We propose a 360 degree integral-floating display with an enhanced vertical viewing angle. The system projects two-dimensional elemental image arrays via a high-speed digital micromirror device projector and reconstructs them into 3D perspectives with a lens array. Double floating lenses relate initial 3D perspectives to the center of a vertically curved convex mirror. The anamorphic optic system tailors the initial 3D perspectives horizontally and vertically disperse light rays more widely. By the proposed method, the entire 3D image provides both monocular and binocular depth cues, a full-parallax demonstration with high-angular ray density and an enhanced vertical viewing angle. PMID:24978984

  18. Anthracnose disease of centipedegrass turf caused by Colletotrichum eremochloae, a new fungal species closely related to Colletotrichum sublineola

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Colletotrichum is a cosmopolitan anamorphic fungal genus responsible for anthracnose disease in hundreds of plant species worldwide, including members of the grass family Poaceae. Anthracnose disease of the widely planted, non-native, warm-season lawn grass, Eremochloa ophiuroides (centipedegrass),...

  19. HYPOCREA RUFA/TRICHODERMA VIRIDE: A REASSESSMENT, AND DESCRIPTION OF THREE CLOSELY RELATED SPECIES WITH AND WITHOUT WARTED CONIDIA

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The type species of the genus Hypocrea (Hypocreaceae, Hypocreales, Ascomycota, Fungi), H. rufa, is re-defined and epitypified using a combination of phenotype (morphology of teleomorphs and anamorphs, and characteristics in culture) and phylogenetic analyses of the translation-elongation factor 1' g...

  20. Yeasts that utilize lactose in sweet whey

    SciTech Connect

    Gholson, J.H.; Gough, R.H.

    1980-01-01

    Since processing costs are usually higher for whey than for other available food or feed nutrients, only about one-third of whey produced in the US is used by food and feed industries. As a result whey disposal costs are a problem. Further; when whey is disposed of through municipal sewerage systems, the lactose present is changed by bacteria to lactic acid which tends to act as a preservative and retards further oxidation of whey constituents. This article describes a method of utilizing lactose-fermenting yeasts to produce large quantities of yeast cells, single-cell protein. Kluveromyces fragilis was found to be the most effective yeast species and the yeast cells produced could be used as a natural food or feed additive. Results of this study determined that certain methods and yeast strains could reduce whey-related pollution and thus help reduce costs of whey disposal.

  1. Fermentation studies using Saccharomyces diastaticus yeast strains

    SciTech Connect

    Erratt, J.A.; Stewart, G.G.

    1981-01-01

    The yeast species, Saccharomyces diastaticus, has the ability to ferment starch and dextrin, because of the extracellular enzyme, glucoamylase, which hydrolyzes the starch/dextrin to glucose. A number of nonallelic genes--DEX 1, DEX 2, and dextrinase B which is allelic to STA 3--have been isolated, which impart to the yeast the ability to ferment dextrin. Various diploid yeast strains were constructed, each being either heterozygous or homozygous for the individual dextrinase genes. Using 12 (sup 0) plato hopped wort (30% corn adjunct) under agitated conditions, the fermentation rates of the various diploid yeast strains were monitored. A gene-dosage effect was exhibited by yeast strains containing DEX 1 or DEX 2, however, not with yeast strains containing dextrinase B (STA 3). The fermentation and growth rates and extents were determined under static conditions at 14.4 C and 21 C. With all yeast strains containing the dextrinase genes, both fermentation and growth were increased at the higher incubation temperature. Using 30-liter fermentors, beer was produced with the various yeast strains containing the dextrinase genes and the physical and organoleptic characteristics of the products were determined. The concentration of glucose in the beer was found to increase during a 3-mo storage period at 21 C, indicating that the glucoamylase from Saccharomyces diastaticus is not inactivated by pasteurization. (Refs. 36).

  2. The wine and beer yeast Dekkera bruxellensis

    PubMed Central

    Schifferdecker, Anna Judith; Dashko, Sofia; Ishchuk, Olena P; Piškur, Jure

    2014-01-01

    Recently, the non-conventional yeast Dekkera bruxellensis has been gaining more and more attention in the food industry and academic research. This yeast species is a distant relative of Saccharomyces cerevisiae and is especially known for two important characteristics: on the one hand, it is considered to be one of the main spoilage organisms in the wine and bioethanol industry; on the other hand, it is 'indispensable' as a contributor to the flavour profile of Belgium lambic and gueuze beers. Additionally, it adds to the characteristic aromatic properties of some red wines. Recently this yeast has also become a model for the study of yeast evolution. In this review we focus on the recently developed molecular and genetic tools, such as complete genome sequencing and transformation, to study and manipulate this yeast. We also focus on the areas that are particularly well explored in this yeast, such as the synthesis of off-flavours, yeast detection methods, carbon metabolism and evolutionary history. © 2014 The Authors. Yeast published by John Wiley & Sons, Ltd. PMID:24932634

  3. Genomics and the making of yeast biodiversity.

    PubMed

    Hittinger, Chris Todd; Rokas, Antonis; Bai, Feng-Yan; Boekhout, Teun; Gonçalves, Paula; Jeffries, Thomas W; Kominek, Jacek; Lachance, Marc-André; Libkind, Diego; Rosa, Carlos A; Sampaio, José Paulo; Kurtzman, Cletus P

    2015-12-01

    Yeasts are unicellular fungi that do not form fruiting bodies. Although the yeast lifestyle has evolved multiple times, most known species belong to the subphylum Saccharomycotina (syn. Hemiascomycota, hereafter yeasts). This diverse group includes the premier eukaryotic model system, Saccharomyces cerevisiae; the common human commensal and opportunistic pathogen, Candida albicans; and over 1000 other known species (with more continuing to be discovered). Yeasts are found in every biome and continent and are more genetically diverse than angiosperms or chordates. Ease of culture, simple life cycles, and small genomes (∼10-20Mbp) have made yeasts exceptional models for molecular genetics, biotechnology, and evolutionary genomics. Here we discuss recent developments in understanding the genomic underpinnings of the making of yeast biodiversity, comparing and contrasting natural and human-associated evolutionary processes. Only a tiny fraction of yeast biodiversity and metabolic capabilities has been tapped by industry and science. Expanding the taxonomic breadth of deep genomic investigations will further illuminate how genome function evolves to encode their diverse metabolisms and ecologies. PMID:26649756

  4. Genomic Evolution of the Ascomycete Yeasts

    SciTech Connect

    Riley, Robert; Haridas, Sajeet; Salamov, Asaf; Boundy-Mills, Kyria; Goker, Markus; Hittinger, Chris; Klenk, Hans-Peter; Lopes, Mariana; Meir-Kolthoff, Jan P.; Rokas, Antonis; Rosa, Carlos; Scheuner, Carmen; Soares, Marco; Stielow, Benjamin; Wisecaver, Jennifer H.; Wolfe, Ken; Blackwell, Meredith; Kurtzman, Cletus; Grigoriev, Igor; Jeffries, Thomas

    2015-03-16

    Yeasts are important for industrial and biotechnological processes and show remarkable metabolic and phylogenetic diversity despite morphological similarities. We have sequenced the genomes of 16 ascomycete yeasts of taxonomic and industrial importance including members of Saccharomycotina and Taphrinomycotina. Phylogenetic analysis of these and previously published yeast genomes helped resolve the placement of species including Saitoella complicata, Babjeviella inositovora, Hyphopichia burtonii, and Metschnikowia bicuspidata. Moreover, we find that alternative nuclear codon usage, where CUG encodes serine instead of leucine, are monophyletic within the Saccharomycotina. Most of the yeasts have compact genomes with a large fraction of single exon genes, and a tendency towards more introns in early-diverging species. Analysis of enzyme phylogeny gives insights into the evolution of metabolic capabilities such as methanol utilization and assimilation of alternative carbon sources.

  5. Phage and Yeast Display.

    PubMed

    Sheehan, Jared; Marasco, Wayne A

    2015-02-01

    Despite the availability of antimicrobial drugs, the continued development of microbial resistance--established through escape mutations and the emergence of resistant strains--limits their clinical utility. The discovery of novel, therapeutic, monoclonal antibodies (mAbs) offers viable clinical alternatives in the treatment and prophylaxis of infectious diseases. Human mAb-based therapies are typically nontoxic in patients and demonstrate high specificity for the intended microbial target. This specificity prevents negative impacts on the patient microbiome and avoids driving the resistance of nontarget species. The in vitro selection of human antibody fragment libraries displayed on phage or yeast surfaces represents a group of well-established technologies capable of generating human mAbs. The advantage of these forms of microbial display is the large repertoire of human antibody fragments present during a single selection campaign. Furthermore, the in vitro selection environments of microbial surface display allow for the rapid isolation of antibodies--and their encoding genes--against infectious pathogens and their toxins that are impractical within in vivo systems, such as murine hybridomas. This article focuses on the technologies of phage display and yeast display, as these strategies relate to the discovery of human mAbs for the treatment and vaccine development of infectious diseases. PMID:26104550

  6. Vaginal Yeast Infections (For Parents)

    MedlinePlus

    ... Can I Help a Friend Who Cuts? Vaginal Yeast Infections KidsHealth > For Teens > Vaginal Yeast Infections Print ... side effect of taking antibiotics. What Is a Yeast Infection? A yeast infection is a common infection ...

  7. 25S ribosomal RNA homologies of basidiomycetous yeasts: taxonomic and phylogenetic implications

    NASA Technical Reports Server (NTRS)

    Baharaeen, S.; Vishniac, H. S.

    1984-01-01

    Genera, families, and possibly orders of basidiomycetous yeasts can be defined by 25S rRNA homology and correlated phenotypic characters. The teleomorphic genera Filobasidium, Leucosporidium, and Rhodosporidium have greater than 96 relative binding percent (rb%) intrageneric 25S rRNA homology and significant intergeneric separation from each other and from Filobasidiella. The anamorphic genus Cryptococcus can be defined by morphology (monopolar budding), colony color, and greater than 75 rb% intrageneric homology; Vanrija is heterogeneous. Agaricostilbum (Phragmobasidiomycetes, Auriculariales), Hansenula (Ascomycotera, Endomycota), Tremella (Phragmobasidiomycetes, Tremellales), and Ustilago (Ustomycota, Ustilaginales) appear equally unrelated to the Cryptococcus, Filobasidiella, and Rhodosporidium spp. used as probes. The Filobasidiaceae and Sporidiaceae, Filobasidiales and Sporidiales, form coherent homology groups which appear to have undergone convergent 25S rRNA evolution, since their relatedness is much greater than that indicated by 5S rRNA homology. Ribosomal RNA homologies do not appear to measure evolutionary distance.

  8. Vaginal Yeast Infection

    MedlinePlus

    ... t diagnose this condition by a person’s medical history and physical examination. They usually diagnose yeast infection by examining vaginal secretions under a microscope for evidence of yeast. Treatment Various antifungal vaginal ...

  9. Vaginal yeast infection

    MedlinePlus

    Yeast infection - vagina; Vaginal candidiasis; Monilial vaginitis ... Most women have a vaginal yeast infection at some time. Candida albicans is a common type of fungus. It is often found in small amounts in the vagina , ...

  10. Vaginal yeast infection

    MedlinePlus

    Yeast infection - vagina; Vaginal candidiasis; Monilial vaginitis ... Most women have a vaginal yeast infection at some time. Candida albicans is a common type of fungus. It is often found in small amounts in the ...

  11. Overwintering of Vineyard Yeasts: Survival of Interacting Yeast Communities in Grapes Mummified on Vines

    PubMed Central

    Sipiczki, Matthias

    2016-01-01

    The conversion of grape must into wine involves the development and succession of yeast populations differing in species composition. The initial population is formed by vineyard strains which are washed into the must from the crushed grapes and then completed with yeasts coming from the cellar environment. As the origin and natural habitat of the vineyard yeasts are not fully understood, this study addresses the possibility, that grape yeasts can be preserved in berries left behind on vines at harvest until the spring of the next year. These berries become mummified during the winter on the vines. To investigate whether yeasts can survive in these overwintering grapes, mummified berries were collected in 16 localities in the Tokaj wine region (Hungary-Slovakia) in early March. The collected berries were rehydrated to recover viable yeasts by plating samples onto agar plates. For the detection of minority species which would not be detected by direct plating, an enrichment step repressing the propagation of alcohol-sensitive yeasts was also included in the process. The morphological, physiological, and molecular analysis identified 13 basidiomycetous and 23 ascomycetous species including fermentative yeasts of wine-making relevance among the 3879 isolates. The presence of viable strains of these species demonstrates that the grapes mummified on the vine can serve as a safe reservoir of yeasts, and may contribute to the maintenance of grape-colonizing yeast populations in the vineyard over years, parallel with other vectors and habitats. All basidiomycetous species were known phylloplane yeasts. Three Hanseniaspora species and pigmented Metschnikowia strains were the most frequent ascomycetes. Other fermentative yeasts of wine-making relevance were detected only in the enrichment cultures. Saccharomyces (S. paradoxus, S. cerevisiae, and S. uvarum) were recovered from 13% of the samples. No Candida zemplinina was found. The isolates with Aureobasidium morphology

  12. The transition from a phytopathogenic smut ancestor to an anamorphic biocontrol agent deciphered by comparative whole-genome analysis.

    PubMed

    Lefebvre, François; Joly, David L; Labbé, Caroline; Teichmann, Beate; Linning, Rob; Belzile, François; Bakkeren, Guus; Bélanger, Richard R

    2013-06-01

    Pseudozyma flocculosa is related to the model plant pathogen Ustilago maydis yet is not a phytopathogen but rather a biocontrol agent of powdery mildews; this relationship makes it unique for the study of the evolution of plant pathogenicity factors. The P. flocculosa genome of ~23 Mb includes 6877 predicted protein coding genes. Genome features, including hallmarks of pathogenicity, are very similar in P. flocculosa and U. maydis, Sporisorium reilianum, and Ustilago hordei. Furthermore, P. flocculosa, a strict anamorph, revealed conserved and seemingly intact mating-type and meiosis loci typical of Ustilaginales. By contrast, we observed the loss of a specific subset of candidate secreted effector proteins reported to influence virulence in U. maydis as the singular divergence that could explain its nonpathogenic nature. These results suggest that P. flocculosa could have once been a virulent smut fungus that lost the specific effectors necessary for host compatibility. Interestingly, the biocontrol agent appears to have acquired genes encoding secreted proteins not found in the compared Ustilaginales, including necrosis-inducing-Phytophthora-protein- and Lysin-motif- containing proteins believed to have direct relevance to its lifestyle. The genome sequence should contribute to new insights into the subtle genetic differences that can lead to drastic changes in fungal pathogen lifestyles. PMID:23800965

  13. Associations of Yeasts with Spotted-Wing Drosophila (Drosophila suzukii; Diptera: Drosophilidae) in Cherries and Raspberries

    PubMed Central

    Hernández, Alejandro; Zalom, Frank G.

    2012-01-01

    A rich history of investigation documents various Drosophila-yeast mutualisms, suggesting that Drosophila suzukii similarly has an association with a specific yeast species or community. To discover candidate yeast species, yeasts were isolated from larval frass, adult midguts, and fruit hosts of D. suzukii. Terminal restriction fragment length polymorphism (TRFLP) technology and decimal dilution plating were used to identify and determine the relative abundance of yeast species present in fruit juice samples that were either infested with D. suzukii or not infested. Yeasts were less abundant in uninfested than infested samples. A total of 126 independent yeast isolates were cultivated from frass, midguts, and fruit hosts of D. suzukii, representing 28 species of yeasts, with Hanseniaspora uvarum predominating. This suggests an association between D. suzukii and H. uvarum that could be utilized for pest management of the highly pestiferous D. suzukii. PMID:22582060

  14. Associations of yeasts with spotted-wing Drosophila (Drosophila suzukii; Diptera: Drosophilidae) in cherries and raspberries.

    PubMed

    Hamby, Kelly A; Hernández, Alejandro; Boundy-Mills, Kyria; Zalom, Frank G

    2012-07-01

    A rich history of investigation documents various Drosophila-yeast mutualisms, suggesting that Drosophila suzukii similarly has an association with a specific yeast species or community. To discover candidate yeast species, yeasts were isolated from larval frass, adult midguts, and fruit hosts of D. suzukii. Terminal restriction fragment length polymorphism (TRFLP) technology and decimal dilution plating were used to identify and determine the relative abundance of yeast species present in fruit juice samples that were either infested with D. suzukii or not infested. Yeasts were less abundant in uninfested than infested samples. A total of 126 independent yeast isolates were cultivated from frass, midguts, and fruit hosts of D. suzukii, representing 28 species of yeasts, with Hanseniaspora uvarum predominating. This suggests an association between D. suzukii and H. uvarum that could be utilized for pest management of the highly pestiferous D. suzukii. PMID:22582060

  15. Production of serpins using yeast expression systems.

    PubMed

    Pemberton, Philip A; Bird, Phillip I

    2004-02-01

    Serpins occupy a unique niche in the field of biology. As more of them are discovered, the need to produce sufficient quantities of each to aid experimental and therapeutic research increases. Yeast expression systems are well suited for the production of recombinant serpins. The genetics of many yeast species is well understood and readily manipulated to induce the targeted over-production of many different serpins. In addition, protease-deficient strains of certain species are available and a few species carry out post-translational modifications resembling those of humans. Yeasts are easy to grow and multiply readily in simple culture media hence the cost of production is low, while the scale of production can be small or large. The disadvantages are the inability of most yeast(s) to perform complex post-translational modifications and a lower product yield of secreted protein compared to intracellular protein production. However, for the intracellular production of serpins, in particular the clade B serpins that do not have complex post-translational modifications, yeast expression systems should be among the first systems considered. PMID:14698631

  16. The wine and beer yeast Dekkera bruxellensis.

    PubMed

    Schifferdecker, Anna Judith; Dashko, Sofia; Ishchuk, Olena P; Piškur, Jure

    2014-09-01

    Recently, the non-conventional yeast Dekkera bruxellensis has been gaining more and more attention in the food industry and academic research. This yeast species is a distant relative of Saccharomyces cerevisiae and is especially known for two important characteristics: on the one hand, it is considered to be one of the main spoilage organisms in the wine and bioethanol industry; on the other hand, it is 'indispensable' as a contributor to the flavour profile of Belgium lambic and gueuze beers. Additionally, it adds to the characteristic aromatic properties of some red wines. Recently this yeast has also become a model for the study of yeast evolution. In this review we focus on the recently developed molecular and genetic tools, such as complete genome sequencing and transformation, to study and manipulate this yeast. We also focus on the areas that are particularly well explored in this yeast, such as the synthesis of off-flavours, yeast detection methods, carbon metabolism and evolutionary history. PMID:24932634

  17. Superoxide anion and hydrogen peroxide in the yeast antagonist-fruit interaction: a new role for reactive oxygen species in postharvest biocontrol?

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The importance of reactive oxygen species (ROS) in plant defense responses against certain pathogens is well documented. There is some evidence that microbial biocontrol agents also induce a transient production of ROS in a host plant which triggers local and systemic defense responses to pathogens....

  18. Four novel yeasts species from decaying organic matter: Blastobotrys robertii sp. nov., Candida cretensis sp. nov., Candida scorzettiae sp. nov. and Candida vadensis sp. nov

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Four novel Candida species are described, two from decaying mushrooms, viz. Candida cretensis and C. vadensis, and two from rotten wood, viz. C. robertii and C. scorzettiae. Accession numbers for the CBS and ARS culture collections, and GenBank accession numbers for the D1/D2 region of the large su...

  19. Hypocrea/Trichoderma: species with conidiophore elongations and green conidia.

    PubMed

    Chaverri, Priscila; Castlebury, Lisa A; Overton, Barrie E; Samuels, Gary J

    2003-01-01

    Species of Trichoderma and Hypocrea that have green conidia and sterile or fertile elongations of their conidiophores are described or redescribed and their phylogenetic position explored. The described species include T. crassum, T. fasciculatum, T. fertile, T. hamatum, T. longipile, T. oblongisporum, T. pubescens, T. spirale, T. strictipile, T. strigosum, T. stromaticum, T. tomentosum, Hypocrea aureoviridis f. macrospora, H. ceramica. and H. semiorbis. Trichoderma fasciculatum originally was described from cultures from ascospores of an unidentified Hypocrea specimen; it is considered to be a synonym of T. strictipile. The remaining species of Trichoderma considered here have not been linked to teleomorphs, and the Trichoderma anamorphs of H. aureoviridis f. macrospora and H. semiorbis have not been named. Five new species of Hypocrea are described, viz. H. cremea, H. cuneispora, H. estonica, H. strictipilosa and H. surrotunda. The phylogenetic relationships of these species were inferred based on partial RPB2 and EF-1α DNA sequence data and phenotypic characteristics, including teleomorph, anamorph, colony and growth rates. Trichoderma crassum was found to be a sister species to T. virens, based on molecular sequences and phenotypic data. Hypocrea surrotunda and H. cremea, H. cuneispora and T. longipile, T. fertile and T. oblongisporum, T. tomentosum and H. atrogelatinosa, and T. hamatum and T. pubescens, respectively, were found to be closely related phylogenetically, based on RPB2 and EF-1α gene genealogies. Anamorph and teleomorph phenotype, including conidiophore elongations, phialide morphology, conidial morphology, stroma anatomy and ascospore morphology are not useful predictors of relationships. Despite the shared phenotypic characters of these Trichoderma and Hypocrea species, they are distributed between two major clades of Trichoderma/Hypocrea. Redescriptions and a key to species of Hypocrea/Trichoderma with green conidia and conidiophore

  20. Epidemiological Cutoff Values for Fluconazole, Itraconazole, Posaconazole, and Voriconazole for Six Candida Species as Determined by the Colorimetric Sensititre YeastOne Method

    PubMed Central

    Pemán, Javier; Iñiguez, Carmen; Hervás, David; Lopez-Hontangas, Jose L.; Pina-Vaz, Cidalia; Camarena, Juan J.; Campos-Herrero, Isolina; García-García, Inmaculada; García-Tapia, Ana M.; Guna, Remedios; Merino, Paloma; Pérez del Molino, Luisa; Rubio, Carmen; Suárez, Anabel

    2013-01-01

    In the absence of clinical breakpoints (CBP), epidemiological cutoff values (ECVs) are useful to separate wild-type (WT) isolates (without mechanisms of resistance) from non-WT isolates (those that can harbor some resistance mechanisms), which is the goal of susceptibility tests. Sensititre YeastOne (SYO) is a widely used method to determine susceptibility of Candida spp. to antifungal agents. The CLSI CBP have been established, but not for the SYO method. The ECVs for four azoles, obtained using MIC distributions determined by the SYO method, were calculated via five methods (three statistical methods and based on the MIC50 and modal MIC). Respectively, the median ECVs (in mg/liter) of the five methods for fluconazole, itraconazole, posaconazole, and voriconazole (in parentheses: the percentage of isolates inhibited by MICs equal to or less than the ECVs; the number of isolates tested) were as follows: 2 (94.4%; 944), 0.5 (96.7%; 942), 0.25 (97.6%; 673), and 0.06 (96.7%; 849) for Candida albicans; 4 (86.1%; 642), 0.5 (99.4%; 642), 0.12 (93.9%; 392), and 0.06 (86.9%; 559) for C. parapsilosis; 8 (94.9%; 175), 1 (93.7%; 175), 2 (93.6%; 125), and 0.25 (90.4%; 167) for C. tropicalis; 128 (98.6%; 212), 4 (95.8%; 212), 4 (96.0%; 173), and 2 (98.5; 205) for C. glabrata; 256 (100%; 53), 1 (98.1%; 53), 1 (100%; 33), and 1 (97.9%; 48) for C. krusei; 4 (89.2%; 93), 0.5 (100%; 93), 0.25 (100%; 33), and 0.06 (87.7%; 73) for C. orthopsilosis. All methods included ≥94% of isolates and yielded similar ECVs (within 1 dilution). These ECVs would be suitable for monitoring emergence of isolates with reduced susceptibility by using the SYO method. PMID:23761155

  1. Yeast diversity in hypersaline habitats.

    PubMed

    Butinar, L; Santos, S; Spencer-Martins, I; Oren, A; Gunde-Cimerman, N

    2005-03-15

    Thus far it has been considered that hypersaline natural brines which are subjected to extreme solar heating, do not contain non-melanized yeast populations. Nevertheless we have isolated yeasts in eight different salterns worldwide, as well as from the Dead Sea, Enriquillo Lake (Dominican Republic) and the Great Salt Lake (Utah). Among the isolates obtained from hypersaline waters, Pichia guilliermondii, Debaryomyces hansenii, Yarrowia lipolytica and Candida parapsilosis are known contaminants of low water activity food, whereas Rhodosporidium sphaerocarpum, R. babjevae, Rhodotorula laryngis, Trichosporon mucoides, and a new species resembling C. glabrata were not known for their halotolerance and were identified for the first time in hypersaline habitats. Moreover, the ascomycetous yeast Metschnikowia bicuspidata, known to be a parasite of the brine shrimp, was isolated as a free-living form from the Great Salt Lake brine. In water rich in magnesium chloride (bitterns) from the La Trinitat salterns (Spain), two new species provisionally named C. atmosphaerica - like and P. philogaea - like were discovered. PMID:15766773

  2. [Invasive yeast infections in neutropenic patients].

    PubMed

    Ruiz Camps, Isabel; Jarque, Isidro

    2016-01-01

    Invasive fungal diseases caused by yeasts still play an important role in the morbidity and mortality in neutropenic patients with haematological malignancies. Although the overall incidence of invasive candidiasis has decreased due to widespread use of antifungal prophylaxis, the incidence of non-Candida albicans Candida species is increasing compared with that of C.albicans, and mortality of invasive candidiasis continues to be high. In addition, there has been an increase in invasive infections caused by an array of uncommon yeasts, including species of the genus Malassezia, Rhodotorula, Trichosporon and Saprochaete, characterised by their resistance to echinocandins and poor prognosis. PMID:27395023

  3. Schizosaccharomyces japonicus: the fission yeast is a fusion of yeast and hyphae.

    PubMed

    Niki, Hironori

    2014-03-01

    The clade of Schizosaccharomyces includes 4 species: S. pombe, S. octosporus, S. cryophilus, and S. japonicus. Although all 4 species exhibit unicellular growth with a binary fission mode of cell division, S. japonicus alone is dimorphic yeast, which can transit from unicellular yeast to long filamentous hyphae. Recently it was found that the hyphal cells response to light and then synchronously activate cytokinesis of hyphae. In addition to hyphal growth, S. japonicas has many properties that aren't shared with other fission yeast. Mitosis of S. japonicas is referred to as semi-open mitosis because dynamics of nuclear membrane is an intermediate mode between open mitosis and closed mitosis. Novel genetic tools and the whole genomic sequencing of S. japonicas now provide us with an opportunity for revealing unique characters of the dimorphic yeast. PMID:24375690

  4. Occurrence of yeasts in faecal samples from Antarctic and South American seabirds.

    PubMed

    Chryssanthou, E; Wennberg, H; Bonnedahl, J; Olsen, B

    2011-11-01

    During an expedition to the Southern Argentinean town of Ushuaia, the Antarctic Peninsula, Antarctic Islands and the Falkland Islands, we collected 94 faecal specimens from wild birds to screen for yeast within the different bird species. The yeast species were identified by morphological features and commercial characterisation kits. From 54% of the specimens, we isolated 122 strains representing 29 yeast species. Debaryomyces hansenii, Candida lambica and Candida krusei were the most frequently isolated species. We found a plethora of yeasts in birds living in proximity to humans, whereas birds living in more remote areas were colonised with a lower number of fungal species. PMID:21672044

  5. Analysis of the RNA Content of the Yeast "Saccharomyces Cerevisiae"

    ERIC Educational Resources Information Center

    Deutch, Charles E.; Marshall, Pamela A.

    2008-01-01

    In this article, the authors describe an interconnected set of relatively simple laboratory experiments in which students determine the RNA content of yeast cells and use agarose gel electrophoresis to separate and analyze the major species of cellular RNA. This set of experiments focuses on RNAs from the yeast "Saccharomyces cerevisiae", a…

  6. Pexophagy in yeasts.

    PubMed

    Oku, Masahide; Sakai, Yasuyoshi

    2016-05-01

    Pexophagy, selective degradation of peroxisomes via autophagy, is the main system for reducing organelle abundance. Elucidation of the molecular machinery of pexophagy has been pioneered in studies of the budding yeast Saccharomyces cerevisiae and the methylotrophic yeasts Pichia pastoris and Hansenula polymorpha. Recent analyses using these yeasts have elucidated the molecular machineries of pexophagy, especially in terms of the interactions and modifications of the so-called adaptor proteins required for guiding autophagic membrane biogenesis on the organelle surface. Based on the recent findings, functional relevance of pexophagy and another autophagic pathway, mitophagy (selective autophagy of mitochondria), is discussed. We also discuss the physiological importance of pexophagy in these yeast systems. PMID:26409485

  7. Effects of yeast subcomponent diet supplements on growth, stress resistance and immune response in Nile tilapia

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Yeast cells contain glucan and mannan subcomponents which have been reported to boost immunity in several fish species. We prepared diets using a commercial feed supplemented with 4 different yeast or yeast subcomponents obtained from commercial sources. These were added at rates recommended by supp...

  8. Yeast Genomics for Bread, Beer, Biology, Bucks and Breath

    NASA Astrophysics Data System (ADS)

    Sakharkar, Kishore R.; Sakharkar, Meena K.

    The rapid advances and scale up of projects in DNA sequencing dur ing the past two decades have produced complete genome sequences of several eukaryotic species. The versatile genetic malleability of the yeast, and the high degree of conservation between its cellular processes and those of human cells have made it a model of choice for pioneering research in molecular and cell biology. The complete sequence of yeast genome has proven to be extremely useful as a reference towards the sequences of human and for providing systems to explore key gene functions. Yeast has been a ‘legendary model’ for new technologies and gaining new biological insights into basic biological sciences and biotechnology. This chapter describes the awesome power of yeast genetics, genomics and proteomics in understanding of biological function. The applications of yeast as a screening tool to the field of drug discovery and development are highlighted and the traditional importance of yeast for bakers and brewers is discussed.

  9. Detection of amphotericin B resistance in Candida haemulonii and closely related species by use of the Etest, Vitek-2 yeast susceptibility system, and CLSI and EUCAST broth microdilution methods.

    PubMed

    Shin, Jong Hee; Kim, Mi-Na; Jang, Sook Jin; Ju, Min Young; Kim, Soo Hyun; Shin, Myung Geun; Suh, Soon Pal; Ryang, Dong Wook

    2012-06-01

    The emerging fungal pathogens Candida haemulonii and Candida pseudohaemulonii often show high-level resistance to amphotericin B (AMB). We compared the utilities of five antifungal susceptibility testing methods, i.e., the Etest using Mueller-Hinton agar supplemented with glucose and methylene blue (Etest-MH), the Etest using RPMI agar supplemented with glucose (Etest-RPG), the Vitek-2 yeast susceptibility system, and the Clinical and Laboratory Standards Institute (CLSI) and European Committee on Antimicrobial Susceptibility Testing (EUCAST) broth microdilution methods, for the detection of AMB-resistant isolates of C. haemulonii and closely related species. Thirty-eight clinical isolates (8 C. haemulonii, 10 C. pseudohaemulonii, and 20 Candida auris isolates) were analyzed. Of the 18 C. haemulonii and C. pseudohaemulonii isolates, 18, 15, 18, 10, and 9 exhibited AMB MICs of >1 μg/ml by the Etest-MH, Etest-RPG, Vitek-2, CLSI, and EUCAST methods, respectively. All 20 C. auris isolates showed AMB MICs of ≤1 μg/ml by all five methods. Of the methods, the Etest-MH generated the broadest distribution of AMB MICs for all 38 isolates and showed the best discrimination between the C. haemulonii and C. pseudohaemulonii isolates (4 to 32 μg/ml) and those of C. auris (0.125 to 0.5 μg/ml). Taking the Etest-MH as the reference method, the essential agreements (within two dilutions) for the Etest-RPG, Vitek-2, CLSI, and EUCAST methods were 84, 92, 55, and 55%, respectively; the categorical agreements were 92, 92, 79, and 76%, respectively. This study provides the first data on the efficacy of the Etest-MH and its excellent agreement with Vitek-2 for discriminating AMB-resistant from AMB-susceptible isolates of these Candida species. PMID:22442324

  10. Utilization of xylan by yeasts and its conversion to ethanol by Pichia stipitis strains. [Cryptococcus; Pichia stipitis; Candida shehatae

    SciTech Connect

    Lee, H.; Biely, P.; Latta, R.K.; Barbosa, M.F.S.; Schneider, H.

    1986-08-01

    Yeasts able to grow on D-xylose were screened for the ability to hydrolyze xylan. Xylanase activity was found to be rare; a total of only 19 of more than 250 strains yielded a positive test result. The activity was localized largely in the genus Cryptococcus and in Pichia stipitis and its anamorph Candida shehatae. The ability to hydrolyze xylan was generally uncoupled from that to hydrolyze cellulose; only three of the xylan-positive strains also yielded a positive test for cellulolytic activity. Of the 19 xylanolytic strains. 2. P. stipitis CBS 5773 and CBS 5775, converted xylan into ethanol, with about 60% of a theoretical yield computed on the basis of the amount of D-xylose present originally that could be released by acid hydrolysis.

  11. Fe(III) mineral reduction followed by partial dissolution and reactive oxygen species generation during 2,4,6-trinitrotoluene transformation by the aerobic yeast Yarrowia lipolytica.

    PubMed

    Ziganshin, Ayrat M; Ziganshina, Elvira E; Byrne, James; Gerlach, Robin; Struve, Ellen; Biktagirov, Timur; Rodionov, Alexander; Kappler, Andreas

    2015-01-01

    Understanding the factors that influence pollutant transformation in the presence of ferric (oxyhydr)oxides is crucial to the efficient application of different remediation strategies. In this study we determined the effect of goethite, hematite, magnetite and ferrihydrite on the transformation of 2,4,6-trinitrotoluene (TNT) by Yarrowia lipolytica AN-L15. The presence of ferric (oxyhydr)oxides led to a small decrease in the rate of TNT removal. In all cases, a significant release of NO2 (-) from TNT and further NO2 (-) oxidation to NO3 (-) was observed. A fraction of the released NO2 (-) was abiotically decomposed to NO and NO2, and then NO was likely oxidized abiotically to NO2 by O2. ESR analysis revealed the generation of superoxide in the culture medium; its further protonation at low pH resulted in the formation of hydroperoxyl radical. Presumably, a fraction of NO released during TNT degradation reacted with superoxide and formed peroxynitrite, which was further rearranged to NO3 (-) at the acidic pH values observed in this study. A transformation and reduction of ferric (oxyhydr)oxides followed by partial dissolution (in the range of 7-86% of the initial Fe(III)) were observed in the presence of cells and TNT. Mössbauer spectroscopy showed some minor changes for goethite, magnetite and ferrihydrite samples during their incubation with Y. lipolytica and TNT. This study shows that i) reactive oxygen and nitrogen species generated during TNT transformation by Y. lipolytica participate in the abiotic conversion of TNT and ii) the presence of iron(III) minerals leads to a minor decrease in TNT transformation. PMID:25852985

  12. Detection and identification of wild yeast contaminants of the industrial fuel ethanol fermentation process.

    PubMed

    Basílio, A C M; de Araújo, P R L; de Morais, J O F; da Silva Filho, E A; de Morais, M A; Simões, D A

    2008-04-01

    Monitoring for wild yeast contaminants is an essential component of the management of the industrial fuel ethanol manufacturing process. Here we describe the isolation and molecular identification of 24 yeast species present in bioethanol distilleries in northeast Brazil that use sugar cane juice or cane molasses as feeding substrate. Most of the yeast species could be identified readily from their unique amplification-specific polymerase chain reaction (PCR) fingerprint. Yeast of the species Dekkera bruxellensis, Candida tropicalis, Pichia galeiformis, as well as a species of Candida that belongs to the C. intermedia clade, were found to be involved in acute contamination episodes; the remaining 20 species were classified as adventitious. Additional physiologic data confirmed that the presence of these major contaminants cause decreased bioethanol yield. We conclude that PCR fingerprinting can be used in an industrial setting to monitor yeast population dynamics to early identify the presence of the most important contaminant yeasts. PMID:18188645

  13. Effect of fungicides on epiphytic yeasts associated with strawberry

    PubMed Central

    Debode, Jane; Van Hemelrijck, Wendy; Creemers, Piet; Maes, Martine

    2013-01-01

    We studied the effect of two commonly used fungicides on the epiphytic yeast community of strawberry. Greenhouse and field experiments were conducted applying Switch (cyprodinil plus fludioxonil) or Signum (boscalid plus pyraclostrobin) to strawberry plants. Yeasts on leaves and fruits were assessed on treated and untreated plants at several time points via plating and denaturing gradient gel electrophoresis (DGGE) analysis. The yeast counts on plates of the treated plants were similar to the control plants. Unripe fruits had 10 times larger yeast concentrations than ripe fruits or leaves. Some dominant yeast types were isolated and in vitro tests showed that they were at least 10 times less sensitive to Switch and Signum as compared with two important fungal strawberry pathogens Botrytis cinerea and Colletotrichum acutatum, which are the targets for the fungicide control. DGGE analysis showed that the applied fungicides had no effect on the composition of the yeast communities, while the growing system, strawberry tissue, and sampling time did affect the yeast communities. The yeast species most commonly identified were Cryptococcus, Rhodotorula, and Sporobolomyces. These results point toward the potential applicability of natural occurring yeast antagonists into an integrated disease control strategy for strawberry diseases.

  14. How to Anamorph

    ERIC Educational Resources Information Center

    Sharp, John

    2010-01-01

    Art uses mathematics in many ways. The author's teaching and involvement with mathematics and art in the Bridges Conference connecting the two have convinced him more and more that concepts for understanding mathematics can be achieved by the use of art. The author states that one reason he believes in teaching mathematics through art is that it…

  15. The influence of Aster x salignus Willd. Invasion on the diversity of soil yeast communities

    NASA Astrophysics Data System (ADS)

    Glushakova, A. M.; Kachalkin, A. V.; Chernov, I. Yu.

    2016-07-01

    The annual dynamics of yeast communities were studied in the soddy-podzolic soil under the thickets of Aster x salignus Willd., one of the widespread invasive plant species in central Russia. Yeast groups in the soils under continuous aster thickets were found to differ greatly from the yeast communities in the soils under the adjacent indigenous meadow vegetation. In both biotopes the same species ( Candida vartiovaarae, Candida sake, and Cryptococcus terreus) are dominants. However, in the soils under indigenous grasses, eurybiontic yeasts Rhodotorula mucilaginosa, which almost never occur in the soil under aster, are widespread. In the soil under aster, the shares of other typical epiphytic and pedobiontic yeast fungi (ascomycetic species Wickerhamomyces aniomalus, Barnettozyma californica and basidiomycetic species Cystofilobasidium macerans, Guehomyces pullulans) significantly increase. Thus, the invasion of Aster x salignus has a clear effect on soil yeast complexes reducing their taxonomic and ecological diversity.

  16. Yeast identification in routine clinical microbiology laboratory and its clinical relevance.

    PubMed

    Agarwal, S; Manchanda, V; Verma, N; Bhalla, P

    2011-01-01

    Rapid identification of yeast infections is helpful in prompt appropriate antifungal therapy. In the present study, the usefulness of chromogenic medium, slide culture technique and Vitek2 Compact (V2C) has been analysed. A total of 173 clinical isolates of yeast species were included in the study. An algorithm to identify such isolates in routine clinical microbiology laboratory was prepared and followed. Chromogenic medium was able to identify Candida albicans, C. tropicalis, C. krusei, C. parapsilosis and Trichosporon asahii. Chromogenic medium was also helpful in identifying "multi-species" yeast infections. The medium was unable to provide presumptive identification of C. pelliculosa, C. utilis, C. rugosa, C. glabrata and C. hemulonii. Vitek 2 compact (V2C) differentiated all pseudohypae non-producing yeast species. The algorithm followed was helpful in timely presumptive identification and final diagnosis of yeast infections, including multi-species yeast infections. PMID:21654115

  17. Yeast Interactions in Inoculated Wine Fermentation

    PubMed Central

    Ciani, Maurizio; Capece, Angela; Comitini, Francesca; Canonico, Laura; Siesto, Gabriella; Romano, Patrizia

    2016-01-01

    The use of selected starter culture is widely diffused in winemaking. In pure fermentation, the ability of inoculated Saccharomyces cerevisiae to suppress the wild microflora is one of the most important feature determining the starter ability to dominate the process. Since the wine is the result of the interaction of several yeast species and strains, many studies are available on the effect of mixed cultures on the final wine quality. In mixed fermentation the interactions between the different yeasts composing the starter culture can led the stability of the final product and the analytical and aromatic profile. In the present review, we will discuss the recent developments regarding yeast interactions in pure and in mixed fermentation, focusing on the influence of interactions on growth and dominance in the process. PMID:27148235

  18. Rapid methods for identification of yeasts.

    PubMed Central

    Huppert, M; Harper, G; Sun, S H; Delanerolle, V

    1975-01-01

    Opportunistic infections by yeasts have been implicated as one of the major causes of complications in the compromised patient. Rapid recognition and identification of these yeasts is essential for patient management, but conventional liquid medium methods for completing identification tests are cumbersome and time consuming. Rapid tests have been devised based on modifications of methods commonly used in bacteriology. These rapid methods included tests for carbohydrate and nitrate assimilation, fermentation, and urease production. These were compared with several current methods for accuracy of results, for time to final identification, and for economy of time and reagents. In addition, the usual tests for pseudogerm tube formation, for production of hyphae or pseudohyphae, and for growth temperatures were included. The rapid tests achieved 96% or better accuracy compared with expected results, and 46 species of yeasts were identified in 1 to 2 days compared with the 10 to 14 days required by conventional liquid culture methods. Images PMID:1241586

  19. Introducing a New Breed of Wine Yeast: Interspecific Hybridisation between a Commercial Saccharomyces cerevisiae Wine Yeast and Saccharomyces mikatae

    PubMed Central

    Bellon, Jennifer R.; Schmid, Frank; Capone, Dimitra L.; Dunn, Barbara L.; Chambers, Paul J.

    2013-01-01

    Interspecific hybrids are commonplace in agriculture and horticulture; bread wheat and grapefruit are but two examples. The benefits derived from interspecific hybridisation include the potential of generating advantageous transgressive phenotypes. This paper describes the generation of a new breed of wine yeast by interspecific hybridisation between a commercial Saccharomyces cerevisiae wine yeast strain and Saccharomyces mikatae, a species hitherto not associated with industrial fermentation environs. While commercially available wine yeast strains provide consistent and reliable fermentations, wines produced using single inocula are thought to lack the sensory complexity and rounded palate structure obtained from spontaneous fermentations. In contrast, interspecific yeast hybrids have the potential to deliver increased complexity to wine sensory properties and alternative wine styles through the formation of novel, and wider ranging, yeast volatile fermentation metabolite profiles, whilst maintaining the robustness of the wine yeast parent. Screening of newly generated hybrids from a cross between a S. cerevisiae wine yeast and S. mikatae (closely-related but ecologically distant members of the Saccharomyces sensu stricto clade), has identified progeny with robust fermentation properties and winemaking potential. Chemical analysis showed that, relative to the S. cerevisiae wine yeast parent, hybrids produced wines with different concentrations of volatile metabolites that are known to contribute to wine flavour and aroma, including flavour compounds associated with non-Saccharomyces species. The new S. cerevisiae x S. mikatae hybrids have the potential to produce complex wines akin to products of spontaneous fermentation while giving winemakers the safeguard of an inoculated ferment. PMID:23614011

  20. Species concepts and biodiversity in Trichoderma and Hypocrea: from aggregate species to species clusters?*

    PubMed Central

    Druzhinina, Irina; Kubicek, Christian P

    2005-01-01

    Trichoderma/Hypocrea is a genus of soil-borne or wood-decaying fungi containing members important to mankind as producers of industrial enzymes and biocontrol agents against plant pathogens, but also as opportunistic pathogens of immunocompromised humans. Species identification, while essential in view of the controversial properties of taxa of this genus, has been problematic by traditional methods. Here we will present a critical survey of the various identification methods in use. In addition, we will present an update on the taxonomy and phylogeny of the 88 taxa (which occur as 14 holomorphs, 49 teleomorphs and 25 anamorphs in nature) of Trichoderma/Hypocrea that have been confirmed by a combination of morphological, physiological and genetic approaches. PMID:15633245

  1. Freeze-drying of yeast cultures.

    PubMed

    Bond, Chris

    2007-01-01

    A method is described that allows yeast species to be stored using a variation on the standard freeze-drying method, which employs evaporative cooling in a two-stage process. Yeast cultures are placed in glass ampoules after having been mixed with a lyoprotectant. Primary drying is carried out using a centrifuge head connected to a standard freeze-dryer. Once the centrifuge head is running, air is removed and evaporated liquid is captured in the freeze-dryer. Centrifugation continues for 15 min and primary drying for a further 3 h. The ampoules are constricted using a glass blowing torch. They are then placed on the freeze-dryer manifold for secondary drying under vacuum overnight, using phosphorus pentoxide as a desiccant. The ampoules are sealed and removed from the manifold by melting the constricted section. Although the process causes an initial large drop in viability, further losses after storage are minimal. Yeast strains have remained viable for more than 30 yr when stored using this method and sufficient cells are recovered to produce new working stocks. Although survival rates are strain specific, nearly all National Collection of Yeast Cultures strains covering most yeast genera, have been successfully stored with little or no detectable change in strain characteristics. PMID:18080464

  2. Influence of pesticides on yeasts colonizing leaves.

    PubMed

    Vadkertiová, Renata; Sláviková, Elena

    2011-01-01

    The effect of nine different pesticides on the growth of yeasts isolated from the leaves of fruit and forest trees was investigated. Four insecticides (with the active ingredients: thiacloprid, deltamethrin, lambdacyhalothrin, and thiamethoxam) and five fungicides (with the effective substances: bitertanol, kresoxim-methyl, mancozeb, trifloxystrobin, and cupric oxychloride) were tested. The concentrations of chemicals were those recommended by the manufacturers for the spraying of trees. The yeast strains isolated from the leaves of fruit trees were not sensitive to any of the insecticides. The majority of yeast strains isolated from the leaves of forest trees were either not sensitive or only to a small extent. While Rhodotorula mucilaginosa and Pichia anomala were not affected by any insecticide, the strains of Cryptococcus laurentii and Rhodotorula glutinis showed the highest sensitivity. The effects of fungicides on the growth of isolated yeasts were more substantial. The fungicide Dithane DG (mancozeb) completely inhibited the growth of all yeasts. All strains isolated from fruit tree leaves were more resistant to the tested fungicides than those isolated from the leaves of forest trees. The most resistant strains from the leaves of fruit trees belonged to the species Metschnikowia pulcherrima, Pichia anomala, and Saccharomyces cerevisiae, whereas Cryptococcus albidus and C. laurentii, originating from the leaves of forest trees, showed the highest sensitivity to fungicides. PMID:22351984

  3. Nitrile Metabolizing Yeasts

    NASA Astrophysics Data System (ADS)

    Bhalla, Tek Chand; Sharma, Monica; Sharma, Nitya Nand

    Nitriles and amides are widely distributed in the biotic and abiotic components of our ecosystem. Nitrile form an important group of organic compounds which find their applications in the synthesis of a large number of compounds used as/in pharmaceutical, cosmetics, plastics, dyes, etc>. Nitriles are mainly hydro-lyzed to corresponding amide/acid in organic chemistry. Industrial and agricultural activities have also lead to release of nitriles and amides into the environment and some of them pose threat to human health. Biocatalysis and biotransformations are increasingly replacing chemical routes of synthesis in organic chemistry as a part of ‘green chemistry’. Nitrile metabolizing organisms or enzymes thus has assumed greater significance in all these years to convert nitriles to amides/ acids. The nitrile metabolizing enzymes are widely present in bacteria, fungi and yeasts. Yeasts metabolize nitriles through nitrilase and/or nitrile hydratase and amidase enzymes. Only few yeasts have been reported to possess aldoxime dehydratase. More than sixty nitrile metabolizing yeast strains have been hither to isolated from cyanide treatment bioreactor, fermented foods and soil. Most of the yeasts contain nitrile hydratase-amidase system for metabolizing nitriles. Transformations of nitriles to amides/acids have been carried out with free and immobilized yeast cells. The nitrilases of Torulopsis candida>and Exophiala oligosperma>R1 are enantioselec-tive and regiospecific respectively. Geotrichum>sp. JR1 grows in the presence of 2M acetonitrile and may have potential for application in bioremediation of nitrile contaminated soil/water. The nitrilase of E. oligosperma>R1 being active at low pH (3-6) has shown promise for the hydroxy acids. Immobilized yeast cells hydrolyze some additional nitriles in comparison to free cells. It is expected that more focus in future will be on purification, characterization, cloning, expression and immobilization of nitrile metabolizing

  4. Catalytic activity of baker's yeast in a mediatorless microbial fuel cell.

    PubMed

    Sayed, Enas Taha; Tsujiguchi, Takuya; Nakagawa, Nobuyoshi

    2012-08-01

    The catalytic activity of baker's yeast, Saccharomyces cerevisiae, as a biocatalyst was investigated in a mediatorless microbial fuel cell. The yeast cells that adhered on the anode surface were the active biocatalyst for glucose oxidation in a mediatorless biofuel cell, suggesting that the electron transfer took place through the surface confined species. The species in the anolyte solution including the dispersed yeast cells did not take a part in the electron transfer and thus in the power generation. PMID:22357359

  5. Forces in yeast flocculation

    PubMed Central

    El-Kirat-Chatel, Sofiane; Beaussart, Audrey; Vincent, Stéphane P.; Flos, Marta Abellán; Hols, Pascal; Lipke, Peter N.; Dufrêne, Yves F.

    2014-01-01

    In the baker's yeast Saccharomyces cerevisiae, cell-cell adhesion (“flocculation”) is conferred by a family of lectin-like proteins known as the flocculin (Flo) proteins. Knowledge of the adhesive and mechanical properties of flocculins is important for understanding the mechanisms of yeast adhesion, and may help controlling yeast behaviour in biotechnology. We use single-molecule and single-cell atomic force microscopy (AFM) to explore the nanoscale forces engaged in yeast flocculation, focusing on the role of Flo1 as a prototype of flocculins. Using AFM tips labelled with mannose, we detect single flocculins on Flo1-expressing cells, showing they are widely exposed on the cell surface. When subjected to force, individual Flo1 proteins display two distinct force responses, i.e. weak lectin binding forces and strong unfolding forces reflecting the force-induced extension of hydrophobic tandem repeats. We demonstrate that cell-cell adhesion bonds also involve multiple weak lectin interactions together with strong unfolding forces, both associated with Flo1 molecules. Single-molecule and single-cell data correlate with microscale cell adhesion behaviour, suggesting strongly that Flo1 mechanics is critical for yeast flocculation. These results favour a model in which not only weak lectin-sugar interactions are involved in yeast flocculation but also strong hydrophobic interactions resulting from protein unfolding. PMID:25515338

  6. Forces in yeast flocculation

    NASA Astrophysics Data System (ADS)

    El-Kirat-Chatel, Sofiane; Beaussart, Audrey; Vincent, Stéphane P.; Abellán Flos, Marta; Hols, Pascal; Lipke, Peter N.; Dufrêne, Yves F.

    2015-01-01

    In the baker's yeast Saccharomyces cerevisiae, cell-cell adhesion (``flocculation'') is conferred by a family of lectin-like proteins known as the flocculin (Flo) proteins. Knowledge of the adhesive and mechanical properties of flocculins is important for understanding the mechanisms of yeast adhesion, and may help controlling yeast behaviour in biotechnology. We use single-molecule and single-cell atomic force microscopy (AFM) to explore the nanoscale forces engaged in yeast flocculation, focusing on the role of Flo1 as a prototype of flocculins. Using AFM tips labelled with mannose, we detect single flocculins on Flo1-expressing cells, showing they are widely exposed on the cell surface. When subjected to force, individual Flo1 proteins display two distinct force responses, i.e. weak lectin binding forces and strong unfolding forces reflecting the force-induced extension of hydrophobic tandem repeats. We demonstrate that cell-cell adhesion bonds also involve multiple weak lectin interactions together with strong unfolding forces, both associated with Flo1 molecules. Single-molecule and single-cell data correlate with microscale cell adhesion behaviour, suggesting strongly that Flo1 mechanics is critical for yeast flocculation. These results favour a model in which not only weak lectin-sugar interactions are involved in yeast flocculation but also strong hydrophobic interactions resulting from protein unfolding.

  7. Anti-Candida activity and biofilm inhibitory effects of secreted products of tropical environmental yeasts.

    PubMed

    Tan, H W; Tay, S T

    2011-04-01

    This study describes the killer phenotypes of tropical environmental yeasts and the inhibition effects of the culture filtrates on the biofilm of Candida albicans. A total of 26 (10.5%) of 258 yeast isolates obtained from an environmental sampling study demonstrated killer activity to Candida species. The killer yeasts were identified as species belonging to the genus Aureobasidium, Pseudozyma, Ustilago and Candida based on sequence analysis of the ITS1-5.8S-ITS2 region of the yeasts. Pseudozyma showed the broadest killing effects against sensitive strains of Candida. New species of Ustilago and Pseudozyma demonstrating killer phenotypes were identified in this study. Interestingly, more than 50% reduction in the metabolic activity of Candida albicans biofilm was noted after exposure to the culture filtrates of the nine killer yeasts. Purification and characterization of toxin and metabolites are essential for understanding the yeast killing effects. PMID:21602784

  8. Improving industrial yeast strains: exploiting natural and artificial diversity.

    PubMed

    Steensels, Jan; Snoek, Tim; Meersman, Esther; Picca Nicolino, Martina; Voordeckers, Karin; Verstrepen, Kevin J

    2014-09-01

    Yeasts have been used for thousands of years to make fermented foods and beverages, such as beer, wine, sake, and bread. However, the choice for a particular yeast strain or species for a specific industrial application is often based on historical, rather than scientific grounds. Moreover, new biotechnological yeast applications, such as the production of second-generation biofuels, confront yeast with environments and challenges that differ from those encountered in traditional food fermentations. Together, this implies that there are interesting opportunities to isolate or generate yeast variants that perform better than the currently used strains. Here, we discuss the different strategies of strain selection and improvement available for both conventional and nonconventional yeasts. Exploiting the existing natural diversity and using techniques such as mutagenesis, protoplast fusion, breeding, genome shuffling and directed evolution to generate artificial diversity, or the use of genetic modification strategies to alter traits in a more targeted way, have led to the selection of superior industrial yeasts. Furthermore, recent technological advances allowed the development of high-throughput techniques, such as 'global transcription machinery engineering' (gTME), to induce genetic variation, providing a new source of yeast genetic diversity. PMID:24724938

  9. Improving industrial yeast strains: exploiting natural and artificial diversity

    PubMed Central

    Steensels, Jan; Snoek, Tim; Meersman, Esther; Nicolino, Martina Picca; Voordeckers, Karin; Verstrepen, Kevin J

    2014-01-01

    Yeasts have been used for thousands of years to make fermented foods and beverages, such as beer, wine, sake, and bread. However, the choice for a particular yeast strain or species for a specific industrial application is often based on historical, rather than scientific grounds. Moreover, new biotechnological yeast applications, such as the production of second-generation biofuels, confront yeast with environments and challenges that differ from those encountered in traditional food fermentations. Together, this implies that there are interesting opportunities to isolate or generate yeast variants that perform better than the currently used strains. Here, we discuss the different strategies of strain selection and improvement available for both conventional and nonconventional yeasts. Exploiting the existing natural diversity and using techniques such as mutagenesis, protoplast fusion, breeding, genome shuffling and directed evolution to generate artificial diversity, or the use of genetic modification strategies to alter traits in a more targeted way, have led to the selection of superior industrial yeasts. Furthermore, recent technological advances allowed the development of high-throughput techniques, such as ‘global transcription machinery engineering’ (gTME), to induce genetic variation, providing a new source of yeast genetic diversity. PMID:24724938

  10. Diversity of soil yeasts isolated from South Victoria Land, Antarctica

    USGS Publications Warehouse

    Connell, L.; Redman, R.; Craig, S.; Scorzetti, G.; Iszard, M.; Rodriguez, R.

    2008-01-01

    Unicellular fungi, commonly referred to as yeasts, were found to be components of the culturable soil fungal population in Taylor Valley, Mt. Discovery, Wright Valley, and two mountain peaks of South Victoria Land, Antarctica. Samples were taken from sites spanning a diversity of soil habitats that were not directly associated with vertebrate activity. A large proportion of yeasts isolated in this study were basidiomycetous species (89%), of which 43% may represent undescribed species, demonstrating that culturable yeasts remain incompletely described in these polar desert soils. Cryptococcus species represented the most often isolated genus (33%) followed by Leucosporidium (22%). Principle component analysis and multiple linear regression using stepwise selection was used to model the relation between abiotic variables (principle component 1 and principle component 2 scores) and yeast biodiversity (the number of species present at a given site). These analyses identified soil pH and electrical conductivity as significant predictors of yeast biodiversity. Species-specific PCR primers were designed to rapidly discriminate among the Dioszegia and Leucosporidium species collected in this study. ?? 2008 Springer Science+Business Media, LLC.

  11. Mapping Yeast Transcriptional Networks

    PubMed Central

    Hughes, Timothy R.; de Boer, Carl G.

    2013-01-01

    The term “transcriptional network” refers to the mechanism(s) that underlies coordinated expression of genes, typically involving transcription factors (TFs) binding to the promoters of multiple genes, and individual genes controlled by multiple TFs. A multitude of studies in the last two decades have aimed to map and characterize transcriptional networks in the yeast Saccharomyces cerevisiae. We review the methodologies and accomplishments of these studies, as well as challenges we now face. For most yeast TFs, data have been collected on their sequence preferences, in vivo promoter occupancy, and gene expression profiles in deletion mutants. These systematic studies have led to the identification of new regulators of numerous cellular functions and shed light on the overall organization of yeast gene regulation. However, many yeast TFs appear to be inactive under standard laboratory growth conditions, and many of the available data were collected using techniques that have since been improved. Perhaps as a consequence, comprehensive and accurate mapping among TF sequence preferences, promoter binding, and gene expression remains an open challenge. We propose that the time is ripe for renewed systematic efforts toward a complete mapping of yeast transcriptional regulatory mechanisms. PMID:24018767

  12. Yeasts in spa establishments.

    PubMed

    Svorcová, L

    1982-05-01

    It was investigated occurrence of yeasts on bathsurfaces, in sauna rooms, in swimming and therapeutic pool water. The number of yeasts decreased depending on patients age, if the rooms were furnished with bath. The lowest contamination was found after bath of 40-60 years-old women. In the saunas were yeasts not found on the upper benches with temperature above 55 degrees C. Much higher counts on lower benches and wood mats with temperature 35-40 degrees C, on basin walls and bottom-up to 10(4)-10(6)/100 cm2. It was isolated 172 yeast strains. The occurrence of some selected strains is given in Table 7, with the toxic effect of disinfectants. The most strains were resistant to Peracetic acid and Chloramin B. Since most of the isolated and determinated strains were found in contaminated environment or during various diseases, the yeasts of the genus Cryptococcus, Candida, Rhodotorula, Torulopsis and Metschnikowia should not occur in bath establishment, and should be classified among indicators of contamination of environment including water. PMID:7124167

  13. Occurrence and diversity of marine yeasts in Antarctica environments

    NASA Astrophysics Data System (ADS)

    Zhang, Xue; Hua, Mingxia; Song, Chunli; Chi, Zhenming

    2012-03-01

    A total of 28 yeast strains were obtained from the sea sediment of Antarctica. According to the results of routine identification and molecular characterization, the strains belonged to species of Yarrowia lipolytica, Debaryomyces hansenii, Rhodotorula slooffiae, Rhodotorula mucilaginosa, Sporidiobolus salmonicolor, Aureobasidium pullulans, Mrakia frigida and Guehomyces pullulans, respectively. The Antarctica yeasts have wide potential applications in biotechnology, for some of them can produce β-galactosidase and killer toxins.

  14. Yeast killer systems.

    PubMed Central

    Magliani, W; Conti, S; Gerloni, M; Bertolotti, D; Polonelli, L

    1997-01-01

    The killer phenomenon in yeasts has been revealed to be a multicentric model for molecular biologists, virologists, phytopathologists, epidemiologists, industrial and medical microbiologists, mycologists, and pharmacologists. The surprisingly widespread occurrence of the killer phenomenon among taxonomically unrelated microorganisms, including prokaryotic and eukaryotic pathogens, has engendered a new interest in its biological significance as well as its theoretical and practical applications. The search for therapeutic opportunities by using yeast killer systems has conceptually opened new avenues for the prevention and control of life-threatening fungal diseases through the idiotypic network that is apparently exploited by the immune system in the course of natural infections. In this review, the biology, ecology, epidemiology, therapeutics, serology, and idiotypy of yeast killer systems are discussed. PMID:9227858

  15. [Fructose transporter in yeasts].

    PubMed

    Lazar, Zbigniew; Dobrowolski, Adam; Robak, Małgorzata

    2014-01-01

    Study of hexoses transporter started with discovery of galactose permease in Saccharomyces cerevisiae. Glucose, fructose and mannose assimilation is assumed by numerous proteins encoded by different genes. To date over 20 hexoses transporters, belonging to Sugar Porter family and to Major Facilitator Superfamily, were known. Genome sequence analysis of Candida glabrata, Kluyveromyces lactis, Yarrowia lipolytica, S. cerevisaie and Debaryomyces hansenii reveled potential presence of 17-48 sugar porter proteins. Glucose transporters in S. cerevisiae have been already characterized. In this paper, hexoses transporters, responsible for assimilation of fructose by cells, are presented and compared. Fructose specific transporter are described for yeasts: Zygosaccharomyces rouxii, Zygosaccharomyces bailli, K. lactis, Saccharomyces pastorianus, S. cerevisiae winemaking strain and for fungus Botritys cinerea and human (Glut5p). Among six yeasts transporters, five are fructose specific, acting by facilitated diffusion or proton symport. Yeasts monosaccharides transporter studies allow understanding of sugars uptake and metabolism important aspects, even in higher eukaryotes cells. PMID:25033548

  16. Recent Taxonomic Developments with Candida and Other Opportunistic Yeasts

    PubMed Central

    Lockhart, Shawn R.

    2015-01-01

    Increases in susceptible patient populations and advances in identification methods have resulted in the continued recognition of novel yeasts as agents of human infection. Most of these agents are members of the well-recognized genera Candida, Cryptococcus, Trichosporon, and Rhodotorula. Some of these agents are “cryptic species,” members of species complexes, and may not be detectable using classical carbohydrate assimilation-based methods of yeast identification. Such species require DNA- or MALDI-based methods for correct identification, although sporadic isolates may not routinely require delineation to the individual species level. The coming end of the fungal taxonomy rules requiring separate names for sexual and asexual forms of the same fungus will hopefully allow greater clarity, as names for medically important yeast can now be based on the needs of the medical mycology community and the common goal of better communication between laboratory and clinician. PMID:26526658

  17. Evolutionary history of Ascomyceteous Yeasts

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Yeasts are important for many industrial and biotechnological processes and show remarkable diversity despite morphological similarities. We have sequenced the genomes of 20 ascomyceteous yeasts of taxonomic and industrial importance including members of Saccharomycotina and Taphrinomycotina. A comp...

  18. Extracellular enzymatic activities and physiological profiles of yeasts colonizing fruit trees.

    PubMed

    Molnárová, Jana; Vadkertiová, Renáta; Stratilová, Eva

    2014-07-01

    Yeasts form a significant and diverse part of the phyllosphere microbiota. Some yeasts that inhabit plants have been found to exhibit extracellular enzymatic activities. The aim of the present study was to investigate the ability of yeasts isolated from leaves, fruits, and blossoms of fruit trees cultivated in Southwest Slovakia to produce extracellular enzymes, and to discover whether the yeasts originating from these plant organs differ from each other in their physiological properties. In total, 92 strains belonging to 29 different species were tested for: extracellular protease, β-glucosidase, lipase, and polygalacturonase activities; fermentation abilities; the assimilation of xylose, saccharose and alcohols (methanol, ethanol, glycerol); and for growth in a medium with 33% glucose. The black yeast Aureobasidium pullulans showed the largest spectrum of activities of all the species tested. Almost 70% of the strains tested demonstrated some enzymatic activity, and more than 90% utilized one of the carbon compounds tested. Intraspecies variations were found for the species of the genera Cryptococcus and Pseudozyma. Interspecies differences of strains exhibiting some enzymatic activities and utilizing alcohols were also noted. The largest proportion of the yeasts exhibited β-glucosidase activity and assimilated alcohols independently of their origin. The highest number of strains positive for all activities tested was found among the yeasts associated with leaves. Yeasts isolated from blossoms assimilated saccharose and D-xylose the most frequently of all the yeasts tested. The majority of the fruit-inhabiting yeasts grew in the medium with higher osmotic pressure. PMID:23744750

  19. Evidence for a Far East Asian origin of lager beer yeast.

    PubMed

    Bing, Jian; Han, Pei-Jie; Liu, Wan-Qiu; Wang, Qi-Ming; Bai, Feng-Yan

    2014-05-19

    Lager-brewing arose in 15th century Bavaria [1] and is nowadays the most popular technique for alcoholic beverage production in the world. The technique is characterized by low temperature fermentation using the domesticated yeast Saccharomyces pastorianus (synonym S. carlsbergensis). It has been clear that the lager yeast is a hybrid with one portion of its genome having originated from S. cerevisiae ale yeast [2]. However, the source of the non-ale subgenome, which endows lager yeast with cold tolerance, had been a matter of debate [3]. Recently, a Patagonian origin hypothesis of lager yeast has been proposed based on the discovery of a new cryotolerant Saccharomyces species from Patagonian native forests of Argentina [4]. This yeast, named S. eubayanus, exhibited the closest known match (99.56%) to the non-ale portion of lager yeast and, thus, was believed to be its progenitor. However, we now show that this yeast species is likely native to the Tibetan Plateau. One of the Tibetan populations of the species exhibits closer affinity with lager yeast than the Patagonian population as inferred from population genetics and genome sequence analyses. We thus provide strong evidence for a Far East Asian origin hypothesis of lager yeast, which apparently corresponds better with geography and world trade history. PMID:24845661

  20. Microarray technology for yeast identification directly from positive blood cultures. A multicenter Italian experience.

    PubMed

    Farina, Claudio; Russello, Giuseppe; Andreoni, Stefano; Bonetti, Cristina; Conte, Marco; Fazi, Paolo; Lombardi, Gianluigi; Luzzaro, Francesco; Manso, Esther; Marone, Piero; Passera, Marco; Rocchetti, Andrea; Sanna, Silvana; Viganò, Egidio Franco

    2012-07-01

    The authors evaluated the performance of the MycArray™ Yeast ID (Myconostica Ltd, UK) assay in the identification of a total of 88 yeast isolates recovered in culture as compared to that obtained through routine methods. The turn-around time for species identification directly from cultures by the MycArray was 6 hours, much quicker than classical methods and all yeasts were correctly identified. In two cases a double identification including Saccharomyces cerevisiae was noted, but it was not confirmed by culture. The results show that MycArray Yeast ID can be a potential tool for rapid detection and identification of Candida species. PMID:22217211

  1. Genetics of Yeasts

    NASA Astrophysics Data System (ADS)

    Querol, Amparo; Fernández-Espinar, M. Teresa; Belloch, Carmela

    The use of yeasts in biotechnology processes dates back to ancient days. Before 7000 BC, beer was produced in Sumeria. Wine was made in Assyria in 3500 BC, and ancient Rome had over 250 bakeries, which were making leavened bread by 100 BC. And milk has been made into Kefyr and Koumiss in Asia for many centuries (Demain, Phaff, & Kurtzman, 1999). However, the importance of yeast in the food and beverage industries was only realized about 1860, when their role in food manufacturing became evident.

  2. L-arabinose fermenting yeast

    DOEpatents

    Zhang, Min; Singh, Arjun; Knoshaug, Eric; Franden, Mary Ann; Jarvis, Eric; Suominen, Pirkko

    2010-12-07

    An L-arabinose utilizing yeast strain is provided for the production of ethanol by introducing and expressing bacterial araA, araB and araD genes. L-arabinose transporters are also introduced into the yeast to enhance the uptake of arabinose. The yeast carries additional genomic mutations enabling it to consume L-arabinose, even as the only carbon source, and to produce ethanol. Methods of producing ethanol include utilizing these modified yeast strains. ##STR00001##

  3. Yeast diversity on grapes in two German wine growing regions.

    PubMed

    Brysch-Herzberg, Michael; Seidel, Martin

    2015-12-01

    The yeast diversity on wine grapes in Germany, one of the most northern wine growing regions of the world, was investigated by means of a culture dependent approach. All yeast isolates were identified by sequence analysis of the D1/D2 domain of the 26S rDNA and the ITS region. Besides Hanseniaspora uvarum and Metschnikowia pulcherrima, which are well known to be abundant on grapes, Metschnikowia viticola, Rhodosporidium babjevae, and Curvibasidium pallidicorallinum, as well as two potentially new species related to Sporidiobolus pararoseus and Filobasidium floriforme, turned out to be typical members of the grape yeast community. We found M. viticola in about half of the grape samples in high abundance. Our data strongly suggest that M. viticola is one of the most important fermenting yeast species on grapes in the temperate climate of Germany. The frequent occurrence of Cu. pallidicorallinum and strains related to F. floriforme is a new finding. The current investigation provides information on the distribution of recently described yeast species, some of which are known from a very few strains up to now. Interestingly yeasts known for their role in the wine making process, such as Saccharomyces cerevisiae, Saccharomyces bayanus ssp. uvarum, Torulaspora delbrueckii, and Zygosaccharomyces bailii, were not found in the grape samples. PMID:26292165

  4. Yeasts associated to Traditional Balsamic Vinegar: ecological and technological features.

    PubMed

    Solieri, L; Giudici, P

    2008-06-30

    Traditional Balsamic Vinegar (TBV) is an Italian homemade vinegar made with cooked grape must through a three-step process: conversion of sugars to ethanol by naturally occurring yeasts; oxidation of ethanol to acetic acid by acetic acid bacteria (AAB); and, finally, at least 12-years ageing. The cooked must is a selective and stressful medium for yeasts growth, due to its high sugar content and low pH values. Recent studies have shown that a large number of yeast species are involved in the fermentation, among them there are Zygosaccharomyces bailii, Zygosaccharomyces rouxii, Zygosaccharomyces pseudorouxii, Zygosaccharomyces mellis, Zygosaccharomyces bisporus, Zygosaccharomyces lentus, Hanseniaspora valbyensis, Hanseniaspora osmophila, Candida lactis-condensi, Candida stellata, Saccharomycodes ludwigii and Saccharomyces cerevisiae. Nevertheless, the TBV-associated yeast population could be even more complex and many other slow-growing or poorly cultivable species might contribute to cooked must fermentation. In this review the main TBV yeast species are described, pointing out their role in TBV production and their influence on final product quality. Finally, both future developments in TBV yeast community studies (culture-independent and metagenomic techniques) and technological advances in TBV making (use of starter culture) are discussed. PMID:17900732

  5. Modeling competition between yeast strains

    NASA Astrophysics Data System (ADS)

    de Gee, Maarten; van Mourik, Hilda; de Visser, Arjan; Molenaar, Jaap

    2016-04-01

    We investigate toxin interference competition between S. cerevisiae colonies grown on a solid medium. In vivo experiments show that the outcome of this competition depends strongly on nutrient availability and cell densities. Here we present a new model for S. cerevisiae colonies, calculating the local height and composition of the colonies. The model simulates yeast colonies that show a good fit to experimental data. Simulations of colonies that start out with a homogeneous mixture of toxin producing and toxin sensitive cells can display remarkable pattern formation, depending on the initial ratio of the strains. Simulations in which the toxin producing and toxin sensitive species start at nearby positions clearly show that toxin production is advantageous.

  6. Conversion of pentoses by yeasts

    SciTech Connect

    Gong, C.S.; Claypool, T.A.; Maun, C.M.; Mccracken, L.D.; Tsao, G.T.; Ueng, P.P.

    1983-01-01

    The utilization and conversion of D-xylose, D-xyulose, L-arabinose, and xylitol by yeast strains have been investigated with the following results: 1) The majority of yeasts tested utilize D-xylose and produce polyols, ethanol, and organic acids. The type and amount of products formed varies with the yeast strains used. The most commonly detected product is xylitol. 2) The majority of yeasts tested utilize D-xylulose aerobically and fermentatively to produce ethanol, xylitol D-arabitol, and organic acids. The type and amount of products varies depending upon the yeast strains used. 3) Xylitol is a poor carbon and energy source for most yeasts tested. Some yeast strains produce small amounts of ethanol from xylitol. 4) Most yeast strains utilize L-arabinose, and L-arabitol is the common product. Small amounts of ethanol are also produced by some yeast strains. 5) Of the four substrates examined, D-xylulose was the preferred substrate, followed by D-xylose, L-arabinose, and xylitol. 6) Mutant yeast strains that exhibit different metabolic product patterns can be induced and isolated from Candida sp. Saccharomyces cerevisiae, and other yeasts. These mutant strains can be used for ethanol production from D-xylose as well as for the study of metabolic regulation of pentose utilization in yeasts.

  7. Lipid raft involvement in yeast cell growth and death

    PubMed Central

    Mollinedo, Faustino

    2012-01-01

    The notion that cellular membranes contain distinct microdomains, acting as scaffolds for signal transduction processes, has gained considerable momentum. In particular, a class of such domains that is rich in sphingolipids and cholesterol, termed as lipid rafts, is thought to compartmentalize the plasma membrane, and to have important roles in survival and cell death signaling in mammalian cells. Likewise, yeast lipid rafts are membrane domains enriched in sphingolipids and ergosterol, the yeast counterpart of mammalian cholesterol. Sterol-rich membrane domains have been identified in several fungal species, including the budding yeast Saccharomyces cerevisiae, the fission yeast Schizosaccharomyces pombe as well as the pathogens Candida albicans and Cryptococcus neoformans. Yeast rafts have been mainly involved in membrane trafficking, but increasing evidence implicates rafts in a wide range of additional cellular processes. Yeast lipid rafts house biologically important proteins involved in the proper function of yeast, such as proteins that control Na+, K+, and pH homeostasis, which influence many cellular processes, including cell growth and death. Membrane raft constituents affect drug susceptibility, and drugs interacting with sterols alter raft composition and membrane integrity, leading to yeast cell death. Because of the genetic tractability of yeast, analysis of yeast rafts could be an excellent model to approach unanswered questions of mammalian raft biology, and to understand the role of lipid rafts in the regulation of cell death and survival in human cells. A better insight in raft biology might lead to envisage new raft-mediated approaches to the treatment of human diseases where regulation of cell death and survival is critical, such as cancer and neurodegenerative diseases. PMID:23087902

  8. Enumeration and rapid identification of yeasts during extraction processes of extra virgin olive oil in Tuscany.

    PubMed

    Mari, Eleonora; Guerrini, Simona; Granchi, Lisa; Vincenzini, Massimo

    2016-06-01

    The aim of this study was to evaluate the occurrence of yeast populations during different olive oil extraction processes, carried out in three consecutive years in Tuscany (Italy), by analysing crushed pastes, kneaded pastes, oil from decanter and pomaces. The results showed yeast concentrations ranging between 10(3) and 10(5) CFU/g or per mL. Seventeen dominant yeast species were identified by random amplified polymorphic DNA with primer M13 and their identification was confirmed by restriction fragments length polymorphism of ribosomal internal transcribed spacer and sequencing rRNA genes. The isolation frequencies of each species in the collected samples pointed out that the occurrence of the various yeast species in olive oil extraction process was dependent not only on the yeasts contaminating the olives but also on the yeasts colonizing the plant for oil extraction. In fact, eleven dominant yeast species were detected from the washed olives, but only three of them were also found in oil samples at significant isolation frequency. On the contrary, the most abundant species in oil samples, Yamadazyma terventina, did not occur in washed olive samples. These findings suggest a phenomenon of contamination of the plant for oil extraction that selects some yeast species that could affect the quality of olive oil. PMID:27116959

  9. Yeast diversity associated to sediments and water from two Colombian artificial lakes

    PubMed Central

    Silva-Bedoya, L.M.; Ramírez-Castrillón, M.; Osorio-Cadavid, E.

    2014-01-01

    In Colombia, knowledge of the yeast and yeast-like fungi community is limited because most studies have focused on species with clinical importance. Sediments and water represent important habitats for the study of yeast diversity, especially for yeast species with industrial, biotechnological, and bioremediation potential. The main purpose of this study was to identify and compare the diversity of yeast species associated with sediment and water samples from two artificial lakes in Universidad del Valle (Cali-Colombia). Yeast samplings were performed from fifteen sediment samples and ten water samples. Grouping of similar isolates was initially based on colony and cell morphology, which was then complemented by micro/mini satellite primed PCR banding pattern analysis by using GTG5 as single primer. A representative isolate for each group established was chosen for D1/D2 domain sequencing and identification. In general, the following yeast species were identified: Candida albicans, Candida diversa, Candida glabrata, Candida pseudolambica, Cryptococcus podzolicus, Cryptococcus rajasthanensis, Cryptococcus laurentii, Williopsis saturnus, Hanseniaspora thailandica, Hanseniaspora uvarum, Rhodotorula mucilaginosa, Saccharomyces cerevisiae, Torulaspora delbrueckii, Torulaspora pretoriensis, Tricosporon jirovecii, Trichosporon laibachii and Yarrowia lypolitica. Two possible new species were also found, belonging to the Issatchenkia sp. and Bullera sp. genera. In conclusion, the lakes at the Universidad del Valle campus have significant differences in yeast diversity and species composition between them. PMID:24948924

  10. Antarctic Yeasts: Biodiversity and Potential Applications

    NASA Astrophysics Data System (ADS)

    Shivaji, S.; Prasad, G. S.

    This review is an attempt in cataloguing the diversity of yeasts in Antarctica, highlight their biotechnological potential and understand the basis of adaptation to low temperature. As of now several psychrophilic and psychrotolerant yeasts from Antarctic soils and marine waters have been characterized with respect to their growth characteristics, ecological distribution and taxonomic significance. Interestingly most of these species belonged to basidiomycetous yeasts which as a group are known for their ability to circumvent and survive under stress conditions. Simultaneously their possible role as work horses in the biotechnological industry was recognized due to their ability to produce novel enzymes and biomolecules such as agents for the breakdown of xenobiotics, and novel pharmaceutical chemi cals. The high activity of psychrophilic enzymes at low and moderate temperatures offers potential economic benefits. As of now lipases from Pseudozyma antarctica have been extensively studied to understand their unique thermal stability at 90°C and also because of its use in the pharmaceutical, agriculture, food, cosmetics and chemical industry. A few of the other enzymes which have been studied include extracellular alpha-amylase and glucoamylase from the yeast Pseudozyma antarctica (Candida antarctica), an extra-cellular protease from Cryptococcus humicola, an aspartyl proteinase from Cryptococcus humicola, a novel extracellular subtilase from Leucosporidium antarcticum, and a xylanase from Cryptococcus adeliensis

  11. Evaluation of the VITEK 2 system for rapid identification of yeasts and yeast-like organisms.

    PubMed

    Graf, B; Adam, T; Zill, E; Göbel, U B

    2000-05-01

    The new VITEK 2 system is a fully automated system dedicated to the identification and susceptibility testing of microorganisms. In conjunction with the VITEK ID-YST card the VITEK 2 system allows the identification of clinically important yeasts and yeast-like organisms in 15 h due to a sensitive fluorescence-based technology. The ID-YST card consists of 47 biochemical reactions. The database comprises 51 taxa, including newly described species. In this study we evaluated the reliability of the VITEK ID-YST card for the identification of yeasts and yeast-like organisms encountered in a clinical microbiology laboratory. A total of 241 strains representing 21 species were studied. The strains were isolated from clinical samples within a period of 60 days prior to the identification. The tests were performed using 24-h to 55-h subcultures on Sabouraud-gentamicin-chloramphenicol agar. Each strain was tested in parallel using the ID 32C strip as a comparison method combined with microscopic morphology and an agglutination test for C. krusei. Overall, 222 strains (92.1%) were unequivocally identified including 11 isolates (4.6%) identified with low discrimination resolved by simple additional tests. Ten strains (4. 1%) for which results were given with low discrimination could not be unequivocally identified with supplemental tests, 4 strains (1. 7%) were misidentified and 5 strains (2.1%) could not be identified. In conclusion, we found that the VITEK 2 system is a rapid and accurate method for the identification of medically important yeasts and yeast-like organisms. PMID:10790099

  12. Opportunistic Pathogenic Yeasts

    NASA Astrophysics Data System (ADS)

    Banerjee, Uma

    Advances in medical research, made during the last few decades, have improved the prophylactic, diagnostic and therapeutic capabilities for variety of infections/diseases. However, many of the prophylactic and therapeutic procedures have been seen in many instances to exact a price of host-vulnerability to an expanding group of opportunistic pathogens and yeasts are one of the important members in it. Fortunately amongst the vast majority of yeasts present in nature only few are considered to have the capability to cause infections when certain opportunities predisposes and these are termed as ‘opportunistic pathogenic yeasts.’ However, the term ‘pathogenic’ is quite tricky, as it depends of various factors of the host, the ‘bug’ and the environment to manifest the clinical infection. The borderline is expanding. In the present century with unprecedented increase in number of immune-compromised host in various disciplines of health care settings, where any yeast, which has the capability to grow at 37 ° C (normal body temperature of human), can be pathogenic and cause infection in particular situation

  13. Sirococcus conigenus, Sirococcus piceicola, sp. nov. and Sirococcus tsugae sp. nov. on conifers: anamorphic fungi in the Gnomoniaceae, Diaporthales

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Sirococcus is a genus of asexually reproducing fungi that includes important pathogens causing shoot blight and tip dieback of conifers. In this paper the type species of Sirococcus, S. conigenus, is redescribed, illustrated, and an epitype designated. In addition, two new species are recognized....

  14. Yeast Modulation of Human Dendritic Cell Cytokine Secretion: An In Vitro Study

    PubMed Central

    Smith, Ida M.; Christensen, Jeffrey E.; Arneborg, Nils; Jespersen, Lene

    2014-01-01

    Probiotics are live microorganisms which when administered in adequate amounts confer a health benefit on the host. The concept of individual microorganisms influencing the makeup of T cell subsets via interactions with intestinal dendritic cells (DCs) appears to constitute the foundation for immunoregulatory effects of probiotics, and several studies have reported probiotic strains resulting in reduction of intestinal inflammation through modulation of DC function. Consequent to a focus on Saccharomyces boulardii as the fundamental probiotic yeast, very little is known about hundreds of non-Saccharomyces yeasts in terms of their interaction with the human gastrointestinal immune system. The aim of the present study was to evaluate 170 yeast strains representing 75 diverse species for modulation of inflammatory cytokine secretion by human DCs in vitro, as compared to cytokine responses induced by a S. boulardii reference strain with probiotic properties documented in clinical trials. Furthermore, we investigated whether cytokine inducing interactions between yeasts and human DCs are dependent upon yeast viability or rather a product of membrane interactions regardless of yeast metabolic function. We demonstrate high diversity in yeast induced cytokine profiles and employ multivariate data analysis to reveal distinct clustering of yeasts inducing similar cytokine profiles in DCs, highlighting clear species distinction within specific yeast genera. The observed differences in induced DC cytokine profiles add to the currently very limited knowledge of the cross-talk between yeasts and human immune cells and provide a foundation for selecting yeast strains for further characterization and development toward potentially novel yeast probiotics. Additionally, we present data to support a hypothesis that the interaction between yeasts and human DCs does not solely depend on yeast viability, a concept which may suggest a need for further classifications beyond the current

  15. Yeast modulation of human dendritic cell cytokine secretion: an in vitro study.

    PubMed

    Smith, Ida M; Christensen, Jeffrey E; Arneborg, Nils; Jespersen, Lene

    2014-01-01

    Probiotics are live microorganisms which when administered in adequate amounts confer a health benefit on the host. The concept of individual microorganisms influencing the makeup of T cell subsets via interactions with intestinal dendritic cells (DCs) appears to constitute the foundation for immunoregulatory effects of probiotics, and several studies have reported probiotic strains resulting in reduction of intestinal inflammation through modulation of DC function. Consequent to a focus on Saccharomyces boulardii as the fundamental probiotic yeast, very little is known about hundreds of non-Saccharomyces yeasts in terms of their interaction with the human gastrointestinal immune system. The aim of the present study was to evaluate 170 yeast strains representing 75 diverse species for modulation of inflammatory cytokine secretion by human DCs in vitro, as compared to cytokine responses induced by a S. boulardii reference strain with probiotic properties documented in clinical trials. Furthermore, we investigated whether cytokine inducing interactions between yeasts and human DCs are dependent upon yeast viability or rather a product of membrane interactions regardless of yeast metabolic function. We demonstrate high diversity in yeast induced cytokine profiles and employ multivariate data analysis to reveal distinct clustering of yeasts inducing similar cytokine profiles in DCs, highlighting clear species distinction within specific yeast genera. The observed differences in induced DC cytokine profiles add to the currently very limited knowledge of the cross-talk between yeasts and human immune cells and provide a foundation for selecting yeast strains for further characterization and development toward potentially novel yeast probiotics. Additionally, we present data to support a hypothesis that the interaction between yeasts and human DCs does not solely depend on yeast viability, a concept which may suggest a need for further classifications beyond the current

  16. L-arabinose fermenting yeast

    SciTech Connect

    Zhang, Min; Singh, Arjun; Suominen, Pirkko; Knoshaug, Eric; Franden, Mary Ann; Jarvis, Eric

    2014-09-23

    An L-arabinose utilizing yeast strain is provided for the production of ethanol by introducing and expressing bacterial araA, araB and araD genes. L-arabinose transporters are also introduced into the yeast to enhance the uptake of arabinose. The yeast carries additional genomic mutations enabling it to consume L-arabinose, even as the only carbon source, and to produce ethanol. A yeast strain engineered to metabolize arabinose through a novel pathway is also disclosed. Methods of producing ethanol include utilizing these modified yeast strains.

  17. L-arabinose fermenting yeast

    SciTech Connect

    Zhang, Min; Singh, Arjun; Suominen, Pirkko; Knoshaug, Eric; Franden, Mary Ann; Jarvis, Eric

    2013-02-12

    An L-arabinose utilizing yeast strain is provided for the production of ethanol by introducing and expressing bacterial araA, araB and araD genes. L-arabinose transporters are also introduced into the yeast to enhance the uptake of arabinose. The yeast carries additional genomic mutations enabling it to consume L-arabinose, even as the only carbon source, and to produce ethanol. A yeast strain engineered to metabolize arabinose through a novel pathway is also disclosed. Methods of producing ethanol include utilizing these modified yeast strains.

  18. Yeast Biomass Production in Brewery's Spent Grains Hemicellulosic Hydrolyzate

    NASA Astrophysics Data System (ADS)

    Duarte, Luís C.; Carvalheiro, Florbela; Lopes, Sónia; Neves, Ines; Gírio, Francisco M.

    Yeast single-cell protein and yeast extract, in particular, are two products which have many feed, food, pharmaceutical, and biotechnological applications. However, many of these applications are limited by their market price. Specifically, the yeast extract requirements for culture media are one of the major technical hurdles to be overcome for the development of low-cost fermentation routes for several top value chemicals in a biorefinery framework. A potential biotechnical solution is the production of yeast biomass from the hemicellulosic fraction stream. The growth of three pentose-assimilating yeast cell factories, Debaryomyces hansenii, Kluyveromyces marxianus, and Pichia stipitis was compared using non-detoxified brewery's spent grains hemicellulosic hydrolyzate supplemented with mineral nutrients. The yeasts exhibited different specific growth rates, biomass productivities, and yields being D. hansenii as the yeast species that presented the best performance, assimilating all sugars and noteworthy consuming most of the hydrolyzate inhibitors. Under optimized conditions, D. hansenii displayed a maximum specific growth rate, biomass yield, and productivity of 0.34 h-1, 0.61 g g-1, and 0.56 g 1-1 h-1, respectively. The nutritional profile of D. hansenii was thoroughly evaluated, and it compares favorably to others reported in literature. It contains considerable amounts of some essential amino acids and a high ratio of unsaturated over saturated fatty acids.

  19. Yeasts Associated with Culex pipiens and Culex theileri Mosquito Larvae and the Effect of Selected Yeast Strains on the Ontogeny of Culex pipiens.

    PubMed

    Steyn, A; Roets, F; Botha, A

    2016-04-01

    The success of mosquitoes in nature has been linked to their microbiota and bacteria in particular. Yet, knowledge on their symbioses with yeasts is lacking. To explore possible associations, culturable yeasts were isolated from wild larvae of Culex pipiens and Culex theileri. These yeasts were classified using restriction fragment length polymorphism (RFLP) analyses and identified by sequencing the D1/D2 region of the 26S rRNA gene. Representative strains of Candida, Cryptococcus, Galactomyces, Hannaella, Meyerozyma, Pichia, Rhodosporidium, Rhodotorula, Trichosporon and Wickerhamomyces were isolated. Our results provide, to our knowledge, the first records of the yeast microbiota from wild mosquito larvae and show that they may harbour potential clinically relevant yeast species, including the well-known opportunistic human pathogen Candida albicans. Also, diminished numbers of yeast isolates originating from adults, compared to larvae, support the hypothesis of microbial reduction/elimination during adult emergence and extend it to include yeasts. In addition, strains of Candida albicans, Candida glabrata, Candida pseudolambica, Cryptococcus gattii, Metschnikowia bicuspidata, Saccharomyces cerevisiae and Wickerhamomyces anomalus were tested as sole feed during a 21-day feeding experiment wherein cumulative larval growth, survival and pupation of Cx. pipiens were recorded. Although most yeasts supported larval growth in a similar manner to the positive control S. cerevisiae strain, the different yeast strains impacted differently on Culex pipiens ontogeny. Notably, survival and pupation of larvae were negatively impacted by a representative strain of the primary pathogen C. gattii - signifying some yeasts to be natural antagonists of mosquitoes. PMID:26573833

  20. Scheffersomyces cryptocercus: a new xylose-fermenting yeast associated with the gut of wood roaches and new combinations in the Sugiyamaella yeast clade.

    PubMed

    Urbina, Hector; Frank, Robert; Blackwell, Meredith

    2013-01-01

    The gut of wood-feeding insects is a microhabitat for a specialized community of microbes, including bacteria and several groups of eukaryotes such as nematodes, parabasalids and fungi. The characterization of gut yeast communities from a variety of insects has shown that certain yeasts often are associated with the insects. The gut of wood-feeding insects is rich in ascomycete yeasts and in particular xylose-fermenting (X-F) and assimilating yeasts have been consistently present in the gut of lignicolous insects. The objective of this study was the characterization of the yeast flora from the gut of the wood roach Cryptocercus sp. (Blattodea: Cryptocercidae). Five wood roaches were collected along the Appalachian Trail near the border between Tennessee and North Carolina, USA. We isolated 18 yeast strains from the wood roaches identified as Sugiyamaella paludigena and Sugiyamaella lignohabitans, xylose-assimilating yeasts, and Scheffersomyces cryptocercus (NRRL Y-48824(T) = CBS 12658) a new species of X-F yeast. The presence of X-F and certain non X-F yeasts in the gut of the subsocial wood roach Cryptocercus sp. extends the previous findings of associations between certain ascomycete yeasts and lignicolous insects. New combinations were made for 13 asexual members of the Sugiyamaella clade. PMID:23233509

  1. Responses of Yeast Biocontrol Agents to Environmental Stress

    PubMed Central

    Sui, Yuan; Wisniewski, Michael; Droby, Samir

    2015-01-01

    Biological control of postharvest diseases, utilizing wild species and strains of antagonistic yeast species, is a research topic that has received considerable attention in the literature over the past 30 years. In principle, it represents a promising alternative to chemical fungicides for the management of postharvest decay of fruits, vegetables, and grains. A yeast-based biocontrol system is composed of a tritrophic interaction between a host (commodity), a pathogen, and a yeast species, all of which are affected by environmental factors such as temperature, pH, and UV light as well as osmotic and oxidative stresses. Additionally, during the production process, biocontrol agents encounter various severe abiotic stresses that also impact their viability. Therefore, understanding the ecological fitness of the potential yeast biocontrol agents and developing strategies to enhance their stress tolerance are essential to their efficacy and commercial application. The current review provides an overview of the responses of antagonistic yeast species to various environmental stresses, the methods that can be used to improve stress tolerance and efficacy, and the related mechanisms associated with improved stress tolerance. PMID:25710368

  2. Biodiversity of cold-adapted yeasts from glacial meltwater rivers in Patagonia, Argentina.

    PubMed

    de García, Virginia; Brizzio, Silvia; Libkind, Diego; Buzzini, Pietro; van Broock, María

    2007-02-01

    The occurrence of culturable yeasts in glacial meltwater from the Frías, Castaño Overo and Río Manso glaciers, located on Mount Tronador in the Nahuel Huapi National Park (Northwestern Patagonia, Argentina) is presented. Subsurface water samples were filtered for colony counting and yeast isolation. The total yeast count ranged between 6 and 360 CFU L(-1). Physiologic and molecular methods were employed to identify 86 yeast isolates. In agreement with yeast diversity data from studies for Antarctic and Alpine glaciers, the genera Cryptococcus, Leucosporidiella, Dioszegia, Rhodotorula, Rhodosporidium, Mrakia, Sporobolomyces, Udeniomyces and Candida were found. Cryptococcus and Leucosporidiella accounted for 50% and 20% of the total number of strains, respectively. Among 21 identified yeast species, Cryptococcus sp. 1 and Leucosporidiella fragaria were the most frequent. The typically psychrophilic Mrakia yeast strain and three new yeast species, yet to be described, were also isolated. All yeast strains were able to grow at 5, 10, and 15 degrees C. Among yeast strains expressing extracellular enzymatic activity, higher proteolytic and lipolytic activities were obtained at 4 degrees C than at 20 degrees C. PMID:17313582

  3. Yeast succession in the Amazon fruit Parahancornia amapa as resource partitioning among Drosophila spp.

    PubMed Central

    Morais, P B; Martins, M B; Klaczko, L B; Mendonça-Hagler, L C; Hagler, A N

    1995-01-01

    The succession of yeasts colonizing the fallen ripe amapa fruit, from Parahancornia amapa, was examined. The occupation of the substrate depended on both the competitive interactions of yeast species, such as the production of killer toxins, and the selective dispersion by the drosophilid guild of the amapa fruit. The yeast community associated with this Amazon fruit differed from those isolated from other fruits in the same forest. The physiological profile of these yeasts was mostly restricted to the assimilation of a few simple carbon sources, mainly L-sorbose, D-glycerol, DL-lactate, cellobiose, and salicin. Common fruit-associated yeasts of the genera Kloeckera and Hanseniaspora, Candida guilliermondii, and Candida krusei colonized fruits during the first three days after the fruit fell. These yeasts were dispersed and served as food for the invader Drosophila malerkotliana. The resident flies of the Drosophila willistoni group fed selectively on patches of yeasts colonizing fruits 3 to 10 days after the fruit fell. The killer toxin-producing yeasts Pichia kluyveri var. kluyveri and Candida fructus were probably involved in the exclusion of some species during the intermediate stages of fruit deterioration. An increase in pH, inhibiting toxin activity and the depletion of simple sugars, may have promoted an increase in yeast diversity in the later stages of decomposition. The yeast succession provided a patchy environment for the drosophilids sharing this ephemeral substrate. PMID:8534092

  4. Yeast Associated with the Ambrosia Beetle, Platypus koryoensis, the Pest of Oak Trees in Korea

    PubMed Central

    Yun, Yeo Hong; Suh, Dong Yeon; Yoo, Hun Dal; Oh, Man Hwan

    2015-01-01

    Oak tree death caused by symbiosis of an ambrosia beetle, Platypus koryoensis, and an ophiostomatoid filamentous fungus, Raffaelea quercus-mongolicae, has been a nationwide problem in Korea since 2004. In this study, we surveyed the yeast species associated with P. koryoensis to better understand the diversity of fungal associates of the beetle pest. In 2009, a total of 195 yeast isolates were sampled from larvae and adult beetles (female and male) of P. koryoensis in Cheonan, Goyang, and Paju; 8 species were identified by based on their morphological, biochemical and molecular analyses. Meyerozyma guilliermondii and Candida kashinagacola were found to be the two dominant species. Among the 8 species, Candida homilentoma was a newly recorded yeast species in Korea, and thus, its mycological characteristics were described. The P. koryoensis symbiont R. quercusmongolicae did not show extracelluar CM-cellulase, xylanase and avicelase activity that are responsible for degradation of wood structure; however, C. kashinagacola and M. guilliermondii did show the three extracellular enzymatic activities. Extracelluar CM-cellulase activity was also found in Ambrosiozyma sp., C. homilentoma, C. kashinagacola, and Candida sp. Extracelluar pectinase activity was detected in Ambrosiozyma sp., C. homilentoma, Candida sp., and M. guilliermondii. All the 8 yeast species displayed compatible relationships with R. quercus-mongolicae when they were co-cultivated on yeast extract-malt extract plates. Overall, our results demonstrated that P. koryoensis carries the yeast species as a symbiotic fungal associate. This is first report of yeast diversity associated with P. koryoensis. PMID:26839506

  5. Yeast Associated with the Ambrosia Beetle, Platypus koryoensis, the Pest of Oak Trees in Korea.

    PubMed

    Yun, Yeo Hong; Suh, Dong Yeon; Yoo, Hun Dal; Oh, Man Hwan; Kim, Seong Hwan

    2015-12-01

    Oak tree death caused by symbiosis of an ambrosia beetle, Platypus koryoensis, and an ophiostomatoid filamentous fungus, Raffaelea quercus-mongolicae, has been a nationwide problem in Korea since 2004. In this study, we surveyed the yeast species associated with P. koryoensis to better understand the diversity of fungal associates of the beetle pest. In 2009, a total of 195 yeast isolates were sampled from larvae and adult beetles (female and male) of P. koryoensis in Cheonan, Goyang, and Paju; 8 species were identified by based on their morphological, biochemical and molecular analyses. Meyerozyma guilliermondii and Candida kashinagacola were found to be the two dominant species. Among the 8 species, Candida homilentoma was a newly recorded yeast species in Korea, and thus, its mycological characteristics were described. The P. koryoensis symbiont R. quercusmongolicae did not show extracelluar CM-cellulase, xylanase and avicelase activity that are responsible for degradation of wood structure; however, C. kashinagacola and M. guilliermondii did show the three extracellular enzymatic activities. Extracelluar CM-cellulase activity was also found in Ambrosiozyma sp., C. homilentoma, C. kashinagacola, and Candida sp. Extracelluar pectinase activity was detected in Ambrosiozyma sp., C. homilentoma, Candida sp., and M. guilliermondii. All the 8 yeast species displayed compatible relationships with R. quercus-mongolicae when they were co-cultivated on yeast extract-malt extract plates. Overall, our results demonstrated that P. koryoensis carries the yeast species as a symbiotic fungal associate. This is first report of yeast diversity associated with P. koryoensis. PMID:26839506

  6. Oxidative Stress and Programmed Cell Death in Yeast

    PubMed Central

    Farrugia, Gianluca; Balzan, Rena

    2012-01-01

    Yeasts, such as Saccharomyces cerevisiae, have long served as useful models for the study of oxidative stress, an event associated with cell death and severe human pathologies. This review will discuss oxidative stress in yeast, in terms of sources of reactive oxygen species (ROS), their molecular targets, and the metabolic responses elicited by cellular ROS accumulation. Responses of yeast to accumulated ROS include upregulation of antioxidants mediated by complex transcriptional changes, activation of pro-survival pathways such as mitophagy, and programmed cell death (PCD) which, apart from apoptosis, includes pathways such as autophagy and necrosis, a form of cell death long considered accidental and uncoordinated. The role of ROS in yeast aging will also be discussed. PMID:22737670

  7. Biodiversity of brewery yeast strains and their fermentative activities.

    PubMed

    Berlowska, Joanna; Kregiel, Dorota; Rajkowska, Katarzyna

    2015-01-01

    We investigated the genetic, biochemical, fermentative and physiological characteristics of brewery yeast strains and performed a hierarchical cluster analysis to evaluate their similarity. We used five different ale and lager yeast strains, originating from different European breweries and deposited at the National Collection of Yeast Cultures (UK). Ale and lager strains exhibited different genomic properties, but their assimilation profiles and pyruvate decarboxylase activities corresponded to their species classifications. The activity of another enzyme, succinate dehydrogenase, varied between different brewing strains. Our results confirmed that ATP and glycogen content, and the activity of the key metabolic enzymes succinate dehydrogenase and pyruvate decarboxylase, may be good general indicators of cell viability. However, the genetic properties, physiology and fermentation capacity of different brewery yeasts are unique to individual strains. PMID:25267007

  8. The Trichoderma koningii aggregate species

    PubMed Central

    Samuels, Gary J.; Dodd, Sarah L.; Lu, Bing-Sheng; Petrini, Orlando; Schroers, Hans-Josef; Druzhinina, Irina S.

    2006-01-01

    The morphological concept of Trichoderma koningii is found to include several species that differ from each other in details of phenotype (including conidium morphology, growth rate) and biogeography. Phylogenetic analysis utilizing partial sequences of the translation-elongation factor 1 alpha (tef1), as well as fragments of actin and calmodulin genes, indicate that phenotypic characters typical of T. koningii evolved independently in three well-separated main lineages. Combined molecular and phenotype data lead to the development of a taxonomy with the recognition of twelve taxonomic species and one variety within the three lineages. These lineages include: (1) T. koningii and T. ovalisporum and the new species T. caribbaeum var. caribbaeum, T. caribbaeum var. aequatoriale, T. dorotheae, T. dingleyae, T. intricatum, T. koningiopsis, T. petersenii and T. taiwanense; (2) the new species T. rogersonii and T. austrokoningii, and (3) the new anamorph T. stilbohypoxyli. Trichoderma koningii s. str. is an uncommon species restricted to Europe and eastern North America; T. caribbaeum var. aequatoriale, T. koningiopsis, and T. ovalisporum were isolated as endophytes of trunks of Theobroma species in tropical America, and T. ovalisporum from the woody liana Banisteropsis caapi in Ecuador; T. koningiopsis is common in tropical America but was isolated also from natural substrata in East Africa, Europe and Canada, and from ascospores in eastern North America, and as an endophyte in Theobroma species; T. stilbohypoxyli, originally described as a parasite of Stilbohypoxylon species in Puerto Rico, is found to be more common in the tropics, besides an endophytic isolate from Fagus in U.K. The additional new species are known almost exclusively from their teleomorphs. Isolates of T. ovalisporum and T. koningiopsis may have biological control potential. A morphophenetic key and a set of tools for molecular species identification were developed. PMID:18490990

  9. Botryosphaeria species from Eucalyptus in Australia are pleoanamorphic, producing dichomera synanamorphs in culture.

    PubMed

    Barber, Paul A; Burgess, Treena J; Hardy, Giles E St J; Slippers, Bernard; Keane, Philip J; Wingfield, Michael J

    2005-12-01

    Species within the genus Botryosphaeria include some of the most widespread and important pathogens of woody plants, and have been the focus of numerous taxonomic studies in recent years. It is currently accepted that anamorphs of Botryosphaeria belong to two distinct genera, Fusicoccum and Diplodia. Species within the genus Fusicoccum commonly produce aseptate, hyaline conidia. In the present study, fungi were isolated from foliage and wood of Eucalyptus in native forests and plantations in Australia. Although these fungi produced Dichomera anamorphs in culture, they clustered within the Fusicoccum clade of Botryosphaeria based on their ITS sequence data. Four species, Botryosphaeria dothidea, B. parva, B. ribis and B. australis produced Dichomera conidia in culture. The Dichomera synanamorphs are described for these four species of Botryosphaeria. In addition, falling within the Fusicoccum clade of Botryosphaeria, two species were found to be distinct from previously described Botryosphaeria spp. based on their ITS sequences, but synonymous with D. versiformis and D. eucalypti. These observations are currently unique to isolates from host trees within the genus Eucalyptus in Australia, and the pleoanamorphic nature of these species is discussed. PMID:16353635

  10. Interactions between Drosophila and its natural yeast symbionts-Is Saccharomyces cerevisiae a good model for studying the fly-yeast relationship?

    PubMed

    Hoang, Don; Kopp, Artyom; Chandler, James Angus

    2015-01-01

    Yeasts play an important role in the biology of the fruit fly, Drosophila melanogaster. In addition to being a valuable source of nutrition, yeasts affect D. melanogaster behavior and interact with the host immune system. Most experiments investigating the role of yeasts in D. melanogaster biology use the baker's yeast, Saccharomyces cerevisiae. However, S. cerevisiae is rarely found with natural populations of D. melanogaster or other Drosophila species. Moreover, the strain of S. cerevisiae used most often in D. melanogaster experiments is a commercially and industrially important strain that, to the best of our knowledge, was not isolated from flies. Since disrupting natural host-microbe interactions can have profound effects on host biology, the results from D. melanogaster-S. cerevisiae laboratory experiments may not be fully representative of host-microbe interactions in nature. In this study, we explore the D. melanogaster-yeast relationship using five different strains of yeast that were isolated from wild Drosophila populations. Ingested live yeasts have variable persistence in the D. melanogaster gastrointestinal tract. For example, Hanseniaspora occidentalis persists relative to S. cerevisiae, while Brettanomyces naardenensis is removed. Despite these differences in persistence relative to S. cerevisiae, we find that all yeasts decrease in total abundance over time. Reactive oxygen species (ROS) are an important component of the D. melanogaster anti-microbial response and can inhibit S. cerevisiae growth in the intestine. To determine if sensitivity to ROS explains the differences in yeast persistence, we measured yeast growth in the presence and absence of hydrogen peroxide. We find that B. naardenesis is completely inhibited by hydrogen peroxide, while H. occidentalis is not, which is consistent with yeast sensitivity to ROS affecting persistence within the D. melanogaster gastrointestinal tract. We also compared the feeding preference of D

  11. Diversity of yeasts associated with the sea surface microlayer and underlying water along the northern coast of Taiwan.

    PubMed

    Chang, Chin-Feng; Lee, Ching-Fu; Lin, Kao-Yung; Liu, Shiu-Mei

    2016-01-01

    Yeast communities inhabiting the sea surface microlayer (SSML) on the northern coast of Taiwan were examined using a cultivation method and compared with those inhabiting the underlying water (UW) at a 50-cm depth. Culturable yeasts were recovered from the SSML and UW samples collected in the morning during 4 field campaigns, and 420 strains were isolated. The 420 isolates were grouped into 43 species using a polyphasic molecular approach, including sequence analysis of the 26S rDNA D1/D2 domain and 5.8S-ITS region. From the SSML samples, 12 genera and 39 species, including 7 new species of Cryptococcus sp. (1), Candida spp. (4), and Rhodotorula spp. (2), were isolated. From the UW samples, 10 genera and 21 species, including one new species of Rhodotorula sp. (1), were isolated. Rhodotorula mucilaginosa was the most abundant species present in the yeast community in SSML (37.6%) and UW (21.6%) samples. Basidiomycetous yeasts (63.6%) and pigmented yeasts (64.5%) comprised the major yeast population. The yeast community in the SSML had a higher species number and abundance than the UW. Moreover, although the majority of yeast community species were from the SSML, individual species distribution in the SSML was unequal. PMID:26343982

  12. Iron toxicity in yeast.

    PubMed

    Wiśnicka, R; Krzepiłko, A; Wawryn, J; Biliński, T

    1997-01-01

    It has been found that yeast cells are sensitive to iron overload only when grown on glucose as a carbon source. Effective concentration of ferrous iron is much higher than that found in natural environments. Effects of ferrous iron are strictly oxygen dependent, what suggest that the formation of hydroxyl radicals in the Fenton reaction is a cause of the toxicity. Respiratory deficiency and pretreatment of cells with antimycin A prevent toxic effects in the late exponential phase of growth, whereas uncouplers and 2mM magnesium salts completely protect even the most vulnerable exponential cells. Generally, toxic effects correlate with the ability of cells to take up this metal. The results presented suggest that during ferrous iron overload iron is transported through the unspecific divalent cation uptake system which is known in fungi. The data suggest that recently described high and low affinity systems of iron uptake in yeast are the only source of iron in natural environments. PMID:9516981

  13. Water Transport in Yeasts.

    PubMed

    Sabir, Farzana; Prista, Catarina; Madeira, Ana; Moura, Teresa; Loureiro-Dias, Maria C; Soveral, Graça

    2016-01-01

    Water moves across membranes through the lipid bilayer and through aquaporins, in this case in a regulated manner. Aquaporins belong to the MIP superfamily and two subfamilies are represented in yeasts: orthodox aquaporins considered to be specific water channels and aquaglyceroporins (heterodox aquaporins). In Saccharomyces cerevisiae genome, four aquaporin isoforms were identified, two of which are genetically close to orthodox aquaporins (ScAqy1 and ScAqy2) and the other two are more closely related to the aquaglyceroporins (ScFps1 and ScAqy3). Advances in the establishment of water channels structure are reviewed in this chapter in relation with the mechanisms of selectivity, conductance and gating. Aquaporins are important for key aspects of yeast physiology. They have been shown to be involved in sporulation, rapid freeze-thaw tolerance, osmo-sensitivity, and modulation of cell surface properties and colony morphology, although the underlying exact mechanisms are still unknown. PMID:26721272

  14. Chromium(VI)-resistant yeast isolated from a sewage treatment plant receiving tannery wastes.

    PubMed Central

    Baldi, F; Vaughan, A M; Olson, G J

    1990-01-01

    A Cr(VI)-resistant yeast, designated strain DBVPG 6502, was isolated from a sewage treatment plant receiving wastes from tannery industries in Italy. The strain was tentatively identified as a species of Candida based on morphological and physiological analyses. This strain was highly resistant to Cr(VI) when compared with eight other yeast species, growing at Cr(VI) concentrations of up to 500 micrograms/ml (10 mM). This resistance was constitutive. The Cr(VI)-resistant yeast did not reduce Cr(VI) to Cr(III) species under aerobic conditions. The yeast showed very little accumulation of Cr(VI). Consequently, the mechanism of resistance of the yeast to Cr(VI) appears to involve reduced accumulation of Cr, as has been shown in Cr(VI)-resistant bacteria. Images PMID:2339879

  15. Bread, beer and wine: yeast domestication in the Saccharomyces sensu stricto complex.

    PubMed

    Sicard, Delphine; Legras, Jean-Luc

    2011-03-01

    Yeasts of the Saccharomyces sensu stricto species complex are able to convert sugar into ethanol and CO(2) via fermentation. They have been used for thousands years by mankind for fermenting food and beverages. In the Neolithic times, fermentations were probably initiated by naturally occurring yeasts, and it is unknown when humans started to consciously add selected yeast to make beer, wine or bread. Interestingly, such human activities gave rise to the creation of new species in the Saccharomyces sensu stricto complex by interspecies hybridization or polyploidization. Within the S. cerevisiae species, they have led to the differentiation of genetically distinct groups according to the food process origin. Although the evolutionary history of wine yeast populations has been well described, the histories of other domesticated yeasts need further investigation. PMID:21377618

  16. Chromium(VI)-resistant yeast isolated from a sewage treatment plant receiving tannery wastes

    SciTech Connect

    Baldi, F.; Vaughan, A.M.; Olson, G.J. )

    1990-04-01

    A Cr(VI)-resistant yeast, designated strain DBVPG 6502, was isolated from a sewage treatment plant receiving wastes from tannery industries in Italy. The strain was tentatively identified as a species of Candida based on morphological and physiological analyses. This strain was highly resistant to Cr(VI) when compared with eight other yeast species, growing at Cr(VI) concentrations of up to 500 micrograms/ml (10 mM). This resistance was constitutive. The Cr(VI)-resistant yeast did not reduce Cr(VI) to Cr(III) species under aerobic conditions. The yeast showed very little accumulation of Cr(VI). Consequently, the mechanism of resistance of the yeast to Cr(VI) appears to involve reduced accumulation of Cr, as has been shown in Cr(VI)-resistant bacteria.

  17. Yeasts associated with fresh and frozen pulps of Brazilian tropical fruits.

    PubMed

    Trindade, Rita C; Resende, Maria Aparecida; Silva, Claudia M; Rosa, Carlos A

    2002-08-01

    The occurrence of yeasts on ripe fruits and frozen pulps of pitanga (Eugenia uniflora L), mangaba (Hancornia speciosa Gom.), umbu (Spondias tuberosa Avr. Cam.), and acerola (Malpighia glaba L) was verified. The incidence of proteolytic, pectinolytic, and mycocinogenic yeasts on these communities was also determined. A total of 480 colonies was isolated and grouped in 405 different strains. These corresponded to 42 ascomycetous and 28 basidiomycetous species. Candida sorbosivorans, Pseudozyma antarctica, C. spandovensis-like, C. spandovensis, Kloeckera apis, C. parapsilosis, Rhodotorula graminis, Kluyveromyces marxianus, Cryptococcus laurentii, Metchnikowia sp (isolated only from pitanga ripe fruits), Issatchenkia occidentalis and C. krusei (isolated only from mangaba frozen pulps), were the most frequent species. The yeast communities from pitanga ripe fruits exhibited the highest frequency of species, followed by communities from acerola ripe fruits and mangaba frozen pulps. Yeast communities from frozen pulp and ripe fruits of umbu had the lowest number of species. Except the yeasts from pitanga, yeast communities from frozen pulp exhibited higher number of yeasts than ripe fruit communities. Mycocinogenic yeasts were found in all of the substrates studied except in communities from umbu ripe fruits and pitanga frozen pulps. Most of the yeasts found to produce mycocins were basidiomycetes and included P. antarctica, Cryptococcus albidus, C. bhutanensis-like, R. graminis and R. mucilaginosa-like from pitanga ripe fruits as well as black yeasts from pitanga and acerola ripe fruits. The umbu frozen pulps community had the highest frequency of proteolytic species. Yeasts able to hydrolyse casein at pH 5.0 represented 38.5% of the species isolated. Thirty-seven percent of yeast isolates were able to hydrolyse casein at pH 7.0. Pectinolytic yeasts were found in all of the communities studied, excepted for those of umbu frozen pulps. The highest frequency of

  18. Yeast Biodiversity from DOQ Priorat Uninoculated Fermentations.

    PubMed

    Padilla, Beatriz; García-Fernández, David; González, Beatriz; Izidoro, Iara; Esteve-Zarzoso, Braulio; Beltran, Gemma; Mas, Albert

    2016-01-01

    Climate, soil, and grape varieties are the primary characteristics of terroir and lead to the definition of various appellations of origin. However, the microbiota associated with grapes are also affected by these conditions and can leave a footprint in a wine that will be part of the characteristics of terroir. Thus, a description of the yeast microbiota within a vineyard is of interest not only to provide a better understanding of the winemaking process, but also to understand the source of microorganisms that maintain a microbial footprint in wine from the examined vineyard. In this study, two typical grape varieties, Grenache and Carignan, have been sampled from four different vineyards in the DOQ Priorat winegrowing region. Afterward, eight spontaneous alcoholic fermentations containing only grapes from one sampling point and of one variety were conducted at laboratory scale. The fermentation kinetics and yeast population dynamics within each fermentation experiment were evaluated. Yeast identification was performed by RFLP-PCR of the 5.8S-ITS region and by sequencing D1/D2 of the 26S rRNA gene of the isolates. The fermentation kinetics did not indicate clear differences between the two varieties of grapes or among vineyards. Approximately 1,400 isolates were identified, exhibiting high species richness in some fermentations. Of all the isolates studied, approximately 60% belong to the genus Hanseniaspora, 16% to Saccharomyces, and 11% to Candida. Other minor genera, such as Hansenula, Issatchenkia, Kluyveromyces, Saccharomycodes, and Zygosaccharomyces, were also found. The distribution of the identified yeast throughout the fermentation process was studied, and Saccharomyces cerevisiae was found to be present mainly at the end of the fermentation process, while Aureobasidium pullulans was isolated primarily during the first days of fermentation in three of the eight spontaneous fermentations. This work highlights the complexity and diversity of the vineyard

  19. Yeast Biodiversity from DOQ Priorat Uninoculated Fermentations

    PubMed Central

    Padilla, Beatriz; García-Fernández, David; González, Beatriz; Izidoro, Iara; Esteve-Zarzoso, Braulio; Beltran, Gemma; Mas, Albert

    2016-01-01

    Climate, soil, and grape varieties are the primary characteristics of terroir and lead to the definition of various appellations of origin. However, the microbiota associated with grapes are also affected by these conditions and can leave a footprint in a wine that will be part of the characteristics of terroir. Thus, a description of the yeast microbiota within a vineyard is of interest not only to provide a better understanding of the winemaking process, but also to understand the source of microorganisms that maintain a microbial footprint in wine from the examined vineyard. In this study, two typical grape varieties, Grenache and Carignan, have been sampled from four different vineyards in the DOQ Priorat winegrowing region. Afterward, eight spontaneous alcoholic fermentations containing only grapes from one sampling point and of one variety were conducted at laboratory scale. The fermentation kinetics and yeast population dynamics within each fermentation experiment were evaluated. Yeast identification was performed by RFLP-PCR of the 5.8S-ITS region and by sequencing D1/D2 of the 26S rRNA gene of the isolates. The fermentation kinetics did not indicate clear differences between the two varieties of grapes or among vineyards. Approximately 1,400 isolates were identified, exhibiting high species richness in some fermentations. Of all the isolates studied, approximately 60% belong to the genus Hanseniaspora, 16% to Saccharomyces, and 11% to Candida. Other minor genera, such as Hansenula, Issatchenkia, Kluyveromyces, Saccharomycodes, and Zygosaccharomyces, were also found. The distribution of the identified yeast throughout the fermentation process was studied, and Saccharomyces cerevisiae was found to be present mainly at the end of the fermentation process, while Aureobasidium pullulans was isolated primarily during the first days of fermentation in three of the eight spontaneous fermentations. This work highlights the complexity and diversity of the vineyard

  20. Combining mutualistic yeast and pathogenic virus - a novel method for control for codling moth control

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Studies evaluated the lethal effectiveness of combining yeasts isolated from larvae of codling moth, Cydia pomonella (L.) with the codling moth granulosis virus (CpGV). Apples were treated with CpGV and three yeast species, including Metschnikowia pulcherrima Pitt and Miller, Cryptococcus tephrensis...

  1. Effect of heat shock treatment on stress tolerance and biocontrol efficacy of biocontrol yeasts

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Several different species of yeasts have been used as biocontrol agents against postharvest diseases of fruits and vegetables. Our current research is directed to develop a better understanding of yeast biology in relation to biocontrol activity and to develop strategies to improve the efficacy of ...

  2. Oropharyngeal Colonization of HIV-Infected Outpatients in Taiwan by Yeast Pathogens▿

    PubMed Central

    Yang, Yun-Liang; Hung, Chien-Ching; Wang, An-Huei; Tseng, Fan-Chen; Leaw, Shiang Ning; Tseng, Yu-Tzu; Su, Chia-Li; Chen, Hui-Ting; Lauderdale, Tsai-Ling; Lo, Hsiu-Jung

    2010-01-01

    Among 234 isolates comprising 26 different Candida species colonizing the oropharynx of 181 (54.3% of 399 surveyed) HIV-infected outpatients, 27 (11.7%) were fluconazole resistant. Antibacterial treatment was associated with increased rates of yeast colonization, while antiretroviral therapy and pneumococcal vaccination protected patients from yeast colonization. PMID:20444970

  3. Oxygen requirements of yeasts. [Saccharomyces cerevisiae; Candida tropicalis

    SciTech Connect

    Visser, W.; Scheffers, W.A.; Batenburg-Van Der Vegte, W.H.; Van Dijken, J.P. )

    1990-12-01

    Type species of 75 yeast genera were examined for their ability to grow anaerobically in complex and mineral media. To define anaerobic conditions, we added a redox indicator, resazurin, to the media to determine low redox potentials. All strains tested were capable of fermenting glucose to ethanol in oxygen-limited shake-flask cultures, even those of species generally regarded as nonfermentative. However, only 23% of the yeast species tested grew under anaerobic conditions. A comparative study with a number of selected strains revealed that Saccharomyces cerevisiae stands out as a yeast capable of rapid growth at low redox potentials. Other yeasts, such as Torulaspora delbrueckii and Candida tropicalis, grew poorly ({mu}{sub max}, 0.03 and 0.05 h{sup {minus}1}, respectively) under anaerobic conditions in mineral medium supplemented with Tween 80 and ergosterol. The latter organisms grew rapidly under oxygen limitation and then displayed a high rate of alcoholic fermentation. It can be concluded that these yeasts have hitherto-unidentified oxygen requirements for growth.

  4. Amplistroma gen. nov. and its relation to Wallrothiella, two genera with globose ascospores and acrodontium-like anamorphs

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Amplistroma is described as a new genus for A. caroliniana, A. diminuspora, A. guianensis, A. hallingii, A. rava, A. tartarea, and A. xylarioides. Species of Amplistroma are distinguished by large stromata of textura intricata with polystichous ascomata and long necks that are either erumpent from t...

  5. Repeat-Associated Fission Yeast-Like Regional Centromeres in the Ascomycetous Budding Yeast Candida tropicalis.

    PubMed

    Chatterjee, Gautam; Sankaranarayanan, Sundar Ram; Guin, Krishnendu; Thattikota, Yogitha; Padmanabhan, Sreedevi; Siddharthan, Rahul; Sanyal, Kaustuv

    2016-02-01

    The centromere, on which kinetochore proteins assemble, ensures precise chromosome segregation. Centromeres are largely specified by the histone H3 variant CENP-A (also known as Cse4 in yeasts). Structurally, centromere DNA sequences are highly diverse in nature. However, the evolutionary consequence of these structural diversities on de novo CENP-A chromatin formation remains elusive. Here, we report the identification of centromeres, as the binding sites of four evolutionarily conserved kinetochore proteins, in the human pathogenic budding yeast Candida tropicalis. Each of the seven centromeres comprises a 2 to 5 kb non-repetitive mid core flanked by 2 to 5 kb inverted repeats. The repeat-associated centromeres of C. tropicalis all share a high degree of sequence conservation with each other and are strikingly diverged from the unique and mostly non-repetitive centromeres of related Candida species--Candida albicans, Candida dubliniensis, and Candida lusitaniae. Using a plasmid-based assay, we further demonstrate that pericentric inverted repeats and the underlying DNA sequence provide a structural determinant in CENP-A recruitment in C. tropicalis, as opposed to epigenetically regulated CENP-A loading at centromeres in C. albicans. Thus, the centromere structure and its influence on de novo CENP-A recruitment has been significantly rewired in closely related Candida species. Strikingly, the centromere structural properties along with role of pericentric repeats in de novo CENP-A loading in C. tropicalis are more reminiscent to those of the distantly related fission yeast Schizosaccharomyces pombe. Taken together, we demonstrate, for the first time, fission yeast-like repeat-associated centromeres in an ascomycetous budding yeast. PMID:26845548

  6. A Proteome-wide Fission Yeast Interactome Reveals Network Evolution Principles from Yeasts to Human.

    PubMed

    Vo, Tommy V; Das, Jishnu; Meyer, Michael J; Cordero, Nicolas A; Akturk, Nurten; Wei, Xiaomu; Fair, Benjamin J; Degatano, Andrew G; Fragoza, Robert; Liu, Lisa G; Matsuyama, Akihisa; Trickey, Michelle; Horibata, Sachi; Grimson, Andrew; Yamano, Hiroyuki; Yoshida, Minoru; Roth, Frederick P; Pleiss, Jeffrey A; Xia, Yu; Yu, Haiyuan

    2016-01-14

    Here, we present FissionNet, a proteome-wide binary protein interactome for S. pombe, comprising 2,278 high-quality interactions, of which ∼ 50% were previously not reported in any species. FissionNet unravels previously unreported interactions implicated in processes such as gene silencing and pre-mRNA splicing. We developed a rigorous network comparison framework that accounts for assay sensitivity and specificity, revealing extensive species-specific network rewiring between fission yeast, budding yeast, and human. Surprisingly, although genes are better conserved between the yeasts, S. pombe interactions are significantly better conserved in human than in S. cerevisiae. Our framework also reveals that different modes of gene duplication influence the extent to which paralogous proteins are functionally repurposed. Finally, cross-species interactome mapping demonstrates that coevolution of interacting proteins is remarkably prevalent, a result with important implications for studying human disease in model organisms. Overall, FissionNet is a valuable resource for understanding protein functions and their evolution. PMID:26771498

  7. Scytalidium parasiticum sp. nov., a New Species Parasitizing on Ganoderma boninense Isolated from Oil Palm in Peninsular Malaysia

    PubMed Central

    Goh, Teik Khiang; Marzuki, Nurul Fadhilah; Tung, Hun Jiat; Goh, You Keng; Goh, Kah Joo

    2015-01-01

    A mycoparasite, Scytalidium parasiticum sp. nov., isolated from the basidiomata of Ganoderma boninense causing basal stem rot of oil palm in Johor, Malaysia, is described and illustrated. It is distinct from other Scytalidium species in having smaller asci and ascospores (teleomorphic stage), longer arthroconidia (anamorphic stage), hyaline to yellowish chlamydospores, and producing a fluorescent pigment. The phylogenetic position of S. parasiticum was determined by sequence analyses of the internal transcribed spacers and the small-subunit ribosomal RNA gene regions. A key to identify Scytalidium species with teleomorphic stage is provided. PMID:26190917

  8. Scytalidium parasiticum sp. nov., a New Species Parasitizing on Ganoderma boninense Isolated from Oil Palm in Peninsular Malaysia.

    PubMed

    Goh, Yit Kheng; Goh, Teik Khiang; Marzuki, Nurul Fadhilah; Tung, Hun Jiat; Goh, You Keng; Goh, Kah Joo

    2015-06-01

    A mycoparasite, Scytalidium parasiticum sp. nov., isolated from the basidiomata of Ganoderma boninense causing basal stem rot of oil palm in Johor, Malaysia, is described and illustrated. It is distinct from other Scytalidium species in having smaller asci and ascospores (teleomorphic stage), longer arthroconidia (anamorphic stage), hyaline to yellowish chlamydospores, and producing a fluorescent pigment. The phylogenetic position of S. parasiticum was determined by sequence analyses of the internal transcribed spacers and the small-subunit ribosomal RNA gene regions. A key to identify Scytalidium species with teleomorphic stage is provided. PMID:26190917

  9. Antifungal chitinase against human pathogenic yeasts from Coprinellus congregatus.

    PubMed

    Yoo, Yeeun; Choi, Hyoung T

    2014-05-01

    The inky cap, Coprinellus congregatus, produces mushrooms which become autolyzed rapidly to generate black liquid droplets, in which no cell wall is detected by microscopy. A chitinase (Chi2) which is synthesized during the autolytic phase of C. congregatus inhibits the growths of Candida albicans and Cryptococcus neoformans up to 10% at the concentration of 10 μg/ml, about 50% at concentration of 20 μg/ml, and up to 95% at the concentration of 70 μg/ml. Upon treatment these yeast cells are observed to be severely deformed, with the formation of large holes in the cell wall. The two yeast species show no growth inhibition at the concentration of 5 μg/ml, which means the minimum inhibitory concentrations for both yeast species are 10 μg/ml under these experimental conditions. PMID:24535739

  10. Volatile codes: Correlation of olfactory signals and reception in Drosophila-yeast chemical communication

    PubMed Central

    Scheidler, Nicole H.; Liu, Cheng; Hamby, Kelly A.; Zalom, Frank G.; Syed, Zainulabeuddin

    2015-01-01

    Drosophila have evolved strong mutualistic associations with yeast communities that best support their growth and survival, resulting in the development of novel niches. It has been suggested that flies recognize their cognate yeasts primarily based on the rich repertoire of volatile organic compounds (VOCs) derived from the yeasts. Thus, it remained an exciting avenue to study whether fly spp. detect and discriminate yeast strains based on odor alone, and if so, how such resolution is achieved by the olfactory system in flies. We used two fly species known to exploit different niches and harboring different yeasts, D. suzukii (a pest of fresh fruit) and D. melanogaster (a saprophytic fly and a neurogenetic model organism). We initially established the behavioral preference of both fly species to six Drosophila-associated yeasts; then chemically analyzed the VOC profile of each yeast which revealed quantitative and qualitative differences; and finally isolated and identified the physiologically active constituents from yeast VOCs for each drosophilid that potentially define attraction. By employing chemical, behavioral, and electrophysiological analyses, we provide a comprehensive portrait of the olfactory neuroethological correlates underlying fly-yeast coadaptation in two drosophilids with distinct habitats. PMID:26391997

  11. Volatile codes: Correlation of olfactory signals and reception in Drosophila-yeast chemical communication.

    PubMed

    Scheidler, Nicole H; Liu, Cheng; Hamby, Kelly A; Zalom, Frank G; Syed, Zainulabeuddin

    2015-01-01

    Drosophila have evolved strong mutualistic associations with yeast communities that best support their growth and survival, resulting in the development of novel niches. It has been suggested that flies recognize their cognate yeasts primarily based on the rich repertoire of volatile organic compounds (VOCs) derived from the yeasts. Thus, it remained an exciting avenue to study whether fly spp. detect and discriminate yeast strains based on odor alone, and if so, how such resolution is achieved by the olfactory system in flies. We used two fly species known to exploit different niches and harboring different yeasts, D. suzukii (a pest of fresh fruit) and D. melanogaster (a saprophytic fly and a neurogenetic model organism). We initially established the behavioral preference of both fly species to six Drosophila-associated yeasts; then chemically analyzed the VOC profile of each yeast which revealed quantitative and qualitative differences; and finally isolated and identified the physiologically active constituents from yeast VOCs for each drosophilid that potentially define attraction. By employing chemical, behavioral, and electrophysiological analyses, we provide a comprehensive portrait of the olfactory neuroethological correlates underlying fly-yeast coadaptation in two drosophilids with distinct habitats. PMID:26391997

  12. The dynamics of the yeast community of the Tagus river estuary: testing the hypothesis of the multiple origins of estuarine yeasts.

    PubMed

    Coelho, Marco A; Almeida, João M F; Martins, Inês M; da Silva, A Jorge; Sampaio, José Paulo

    2010-10-01

    Yeasts are common inhabitants of different types of aquatic habitats, including marine and estuarine waters and rivers. Although numerous studies have surveyed yeast occurrence in these habitats, the identification of autochthonous populations has been problematic because several yeast species seem to be very versatile and therefore mere presence is not sufficient to establish an ecological association. In the present study we investigated the dynamics of the yeast community in the Tagus river estuary (Portugal) by combining a microbiological study involving isolation, quantification, and molecular identification of dominant yeast populations with the analysis of hydrological and hydrographical data. We set out to test the hypothesis of the multiple origins of estuarine yeast populations in a transect of the Tagus estuary and we postulate four possible sources: open sea, terrestrial, gastrointestinal and the estuary itself in the case of populations that have become resident. Candida parapsilosis and Pichia guilliermondii were correlated with Escherichia coli, which indicated an intestinal origin. Other cream-colored yeasts like Debaryomyces hansenii and Candida zeylanoides had similar dynamics, but no association with E. coli and quite distinct ecological preferences. They might represent a group of resident estuarine populations whose primary origin is diverse and can include marine, terrestrial, and gastrointestinal habitats. Another major yeast population was represented by Rhodotorula mucilaginosa. The cosmopolitan nature of that species and its moderate association with E. coli point to terrestrial sources as primary habitats. PMID:20422287

  13. Marine yeasts as biocontrol agents and producers of bio-products.

    PubMed

    Chi, Zhen-Ming; Liu, Guanglei; Zhao, Shoufeng; Li, Jing; Peng, Ying

    2010-05-01

    As some species of marine yeasts can colonize intestine of marine animals, they can be used as probiotics. It has been reported that beta-glucans from marine yeast cells can be utilized as immuno-stimulants in marine animals. Some siderophores or killer toxins produced by marine yeasts have ability to inhibit growth of pathogenic bacteria or kill pathogenic yeasts in marine animals. The virulent factors from marine pathogens can be genetically displayed on marine yeast cells, and the yeast cells displaying the virulent factors can stimulate marine animals to produce specific antibody against the pathogens. Some marine yeast cells are rich in proteins and essential amino acids and can be used in nutrition for marine animals. The marine yeast cells rich in lipid can be used for biodiesel production. Recently, it has been reported that some strains of Yarrowia lipolytica isolated from marine environments can produce nanoparticles. Because many marine yeasts can remove organic pollutants and heavy metals, they can be applied to remediation of marine environments. It has been shown that the enzymes produced by some marine yeasts have many unique properties and many potential applications. PMID:20195858

  14. Yeasts in foods and beverages: impact on product quality and safety.

    PubMed

    Fleet, Graham H

    2007-04-01

    The role of yeasts in food and beverage production extends beyond the well-known bread, beer and wine fermentations. Molecular analytical technologies have led to a major revision of yeast taxonomy, and have facilitated the ecological study of yeasts in many other products. The mechanisms by which yeasts grow in these ecosystems and impact on product quality can now be studied at the level of gene expression. Their growth and metabolic activities are moderated by a network of strain and species interactions, including interactions with bacteria and other fungi. Some yeasts have been developed as agents for the biocontrol of food spoilage fungi, and others are being considered as novel probiotic organisms. The association of yeasts with opportunistic infections and other adverse responses in humans raises new issues in the field of food safety. PMID:17275276

  15. Yeast and yeast-like fungi associated with dry indehiscent fruits of Nothofagus nervosa in Patagonia, Argentina.

    PubMed

    Fernández, Natalia V; Mestre, M Cecilia; Marchelli, Paula; Fontenla, Sonia B

    2012-04-01

    Nothofagus nervosa (Raulí) is a native tree species that yields valuable timber. It was overexploited in the past and is currently included in domestication and conservation programs. Several research programs have focused on the characterization of epiphytic microorganisms because it has been demonstrated that they can affect plant-pathogen interactions and/or promote plant growth. Although the microbial ecology of leaves has been well studied, less is known about microorganisms occurring on seeds and noncommercial fruits. In this work, we analyzed the yeast and yeast-like fungi present on N. nervosa fruits destined for the propagation of this species, as well as the effects of fruit preservation and seed dormancy-breaking processes on fungal diversity. Morphological and molecular methods were used, and differences between fungal communities were analyzed using a similarity index. A total of 171 isolates corresponding to 17 species were recovered, most of which belong to the phylum Ascomycota. The majority of the species develop mycelia, produce pigments and mycosporines, and these adaptation strategies are discussed. It was observed that the preservation process considerably reduced yeast and yeast-like fungal diversity. This is the first study concerning microbial communities associated with this ecologically and economically important species, and the information presented is relevant to domestication programs. PMID:22224476

  16. Advances in Gene Expression in Non-Conventional Yeasts

    NASA Astrophysics Data System (ADS)

    Nel, Sanet; Labuschagne, Michel; Albertyn, Jacobus

    Yeast has been a favoured lower eukaryotic system for the expression and production of recombinant proteins for both basic research and practical applications, and the demand for foreign-gene expression systems is increasing rapidly. Despite the vast amount of information on the molecular biology and physiology of Saccharomyces cerevisiae, which has consequently been the first choice as host system for recombinant protein production in the past, several limitations have been identified in this expression system. These limitations have recently been relieved by the development of expression systems in other yeast species known as ‘ non-conventional yeasts’ or ‘non-Saccharomyces ’ yeasts. With the increasing interest in the biotechnological applications of these yeasts in applied and fundamental studies and processes, the term ‘ non-conventional ’ yeast may well soon become redundant. As there is no universal expression system for heterologous protein production, it is necessary to recognize the merits and demerits of each system in order to make a right choice. This chapter will evaluate the competitive environment of non-conventional expression platforms represented by some of the best-known alternative yeasts systems including Kluyveromyces lactis, Yarrowia lipolytica, Hansenula polymorpha, Pichia pastoris and more recently, Arxula adeninivorans.

  17. The Fermentative and Aromatic Ability of Kloeckera and Hanseniaspora Yeasts

    NASA Astrophysics Data System (ADS)

    Díaz-Montaño, Dulce M.; de Jesús Ramírez Córdova, J.

    Spontaneous alcoholic fermentation from grape, agave and others musts into an alcoholic beverage is usually characterized by the presence of several non-Saccharomyces yeasts. These genera yeasts are dominant in the early stages of the alcoholic fermentation. However the genera Hanseniaspora and Kloeckera may survive at a significant level during fermentation and can influence the chemical composition of the beverage. Several strains belonging to the species Kloeckera api-culata and Hanseniaspora guilliermondii have been extensively studied in relation to the formation of some metabolic compounds affecting the bouquet of the final product. Indeed some apiculate yeast showed positive oenological properties and their use in the alcoholic fermentations has been suggested to enhance the aroma and flavor profiles. The non- Saccharomyces yeasts have the capability to produce and secrete enzymes in the medium, such as β -glucosidases, which release monoterpenes derived from their glycosylated form. These compounds contribute to the higher fruit-like characteristic of final product. This chapter reviews metabolic activity of Kloeckera and Hanseniaspora yeasts in several aspects: fermentative capability, aromatic compounds production and transformation of aromatic precursor present in the must, also covers the molecular methods for identifying of the yeast

  18. Basic principles of yeast genomics, a personal recollection.

    PubMed

    Dujon, Bernard

    2015-08-01

    The genomes of many yeast species or strain isolates have now been sequenced with an accelerating momentum that quickly relegates initial data to history, albeit that they are less than two decades old. Today, novel yeast genomes are entirely sequenced for a variety of reasons, often only to identify a few expected genes of specific interest, thus providing a wealth of data, heterogenous in quality and completion but informative about the origin and evolution of this heterogeneous collection of unicellular modern fungi. However, how many scientists fully appreciate the important conceptual and technological roles played by yeasts in the extraordinary development of today's genomics? Novel notions of general significance emerged from the very first eukaryote sequenced, Saccharomyces cerevisiae, and were successively refined and extended over time. Tools with general applications were originally developed with this yeast; and surprises emerged from the results. Here, I have tried to recollect the gradual building up of knowledge as yeast genomics developed, and then briefly summarize our present views about the basic nature of yeast genomes, based on the most recent data. PMID:26071597

  19. Zygoascus hellenicus gen. nov., sp. nov., the teleomorph of Candida hellenica (= C. inositophila = C. steatolytica).

    PubMed

    Smith, M T

    1986-01-01

    The anamorphic yeast species Candida hellenica, C. inositophila and C. steatolytica were found to constitute haploid mating types of an undescribed, filamentous heterothallic Endomycete. The new genus Zygoascus is proposed for the teleomorph. Descriptions are given of the genus and type species, Z. hellenicus. PMID:3729369

  20. [Determination of riboflavin kinase activity in yeast].

    PubMed

    Shavlovsky, G M; Kashchenko, V E

    1975-01-01

    It is established that the main reason of the riboflavin kinase (RFK, EC 2.7.1.26) low specific activity in the cell-free extracts of the yeast Pichia guillermondii Wickerham ATCC 9058 is the presence of alkaline phosphatase (EC 3.1.3.1), effectively destructing flaven mononucleotide. By chromatography of the cell-free extracts of P. guillermondii on DEAE-Sephadex A-50, CM-Sphadex C-50, CM-cellulose, Sephadexes G-75 and G-100 RFK and alkaline phosphatase may be separated completely. Any of these procedures results in a several times increase of the RFK activity as compared with the initial preparation. One failed to obtain a similar effect by fractionation of the extracts with amminium sulphate and by hydroxylapatite chromatography. A simple method is developed for determining the activity of RFK in the cell-free extracts of yeast on the basis of negative adsorption of this enzyme on DEAE-Sephadex A-50. A selective inhibition of alkaline phosphatase by ions Be2+ and F- yields a less satisfactory result. The data are presented on the PFK activity of certain species of flavinogenic (Pichia guillermondii, Torulopsis camdida) and non-flavinogenic (Pichia ohmeri, Candida utilis, Saccharomyces cervisiae) yeast. PMID:174262

  1. Polyphenolic substrates and dyes degradation by yeasts from 25 de Mayo/King George Island (Antarctica).

    PubMed

    Rovati, José I; Pajot, Hipólito F; Ruberto, Lucas; Mac Cormack, Walter; Figueroa, Lucía I C

    2013-11-01

    Antarctica offers a range of extreme climatic conditions, such as low temperatures, high solar radiation and low nutrient availability, and constitutes one of the harshest environments on Earth. Despite that, it has been successfully colonized by ’cold-loving’ fungi, which play a key role in decomposition cycles in cold ecosystems. However, knowledge about the ecological role of yeasts in nutrient or organic matter recycling/mineralization remains highly fragmentary. The aim of this work was to study the yeast microbiota in samples collected on 25 de Mayo/King George Island regarding the scope of their ability to degrade polyphenolic substrates such as lignin and azo dyes. Sixty-one yeast isolates were obtained from 37 samples, including soil, rocks, wood and bones. Molecular analyses based on rDNA sequences revealed that 35 yeasts could be identified at the species level and could be classified in the genera Leucosporidiella, Rhodotorula, Cryptococcus, Bullera and Candida. Cryptococcus victoriae was by far the most ubiquitous species. In total, 33% of the yeast isolates examined showed significant activity for dye decolorization, 25% for laccase activity and 38% for ligninolytic activity. Eleven yeasts did not show positive activity in any of the assays performed and no isolates showed positive activity across all tested substrates. A high diversity of yeasts were isolated in this work, possibly including undescribed species and conspicuous Antarctic yeasts, most of them belonging to oligotrophic, slow-growing and metabolically diverse basidiomycetous genera. PMID:24298603

  2. Yeast communities in two Atlantic rain Forest fragments in Southeast Brazil.

    PubMed

    Pimenta, Raphael S; Alves, Priscila D D; Almeida, Gabriel M F; Silva, Juliana F M; Morais, Paula B; Corrêa, Ary; Rosa, Carlos A

    2009-01-01

    We studied the yeast communities associated with fruits, mushrooms, tree exudates, and flies of the genus Drosophila, in two Atlantic Rain Forest fragments in state of Minas Gerais, Brazil. A total of 456 samples were collected from Rio Doce State Park and 142 from Ecological Station of Universidade Federal de Minas Gerais. From these samples, 608 yeast isolates were obtained, belonging to 71 different species. Among the yeasts isolated from Rio Doce State Park, 17 isolates were recovered from fruits, 12 from mushrooms, 13 from tree exudates, and 299 from Drosophila spp. In the Ecological Station of Universidade Federal de Minas Gerais, 24 isolates were recovered from fruits and 243 from Drosophila spp. Distinct communities of yeast were observed in Drosophila flies, fruits, mushrooms and tree exudates. The highest number of yeast species was recovered from Drosophila flies suggesting that flies are the natural vectors of these microorganisms. PMID:24031324

  3. Yeast communities in two Atlantic rain Forest fragments in Southeast Brazil

    PubMed Central

    Pimenta, Raphael S.; Alves, Priscila D. D.; Almeida, Gabriel M. F.; Silva, Juliana F.M; Morais, Paula B.; Corrêa Jr., Ary; Rosa, Carlos A.

    2009-01-01

    We studied the yeast communities associated with fruits, mushrooms, tree exudates, and flies of the genus Drosophila, in two Atlantic Rain Forest fragments in state of Minas Gerais, Brazil. A total of 456 samples were collected from Rio Doce State Park and 142 from Ecological Station of Universidade Federal de Minas Gerais. From these samples, 608 yeast isolates were obtained, belonging to 71 different species. Among the yeasts isolated from Rio Doce State Park, 17 isolates were recovered from fruits, 12 from mushrooms, 13 from tree exudates, and 299 from Drosophila spp. In the Ecological Station of Universidade Federal de Minas Gerais, 24 isolates were recovered from fruits and 243 from Drosophila spp. Distinct communities of yeast were observed in Drosophila flies, fruits, mushrooms and tree exudates. The highest number of yeast species was recovered from Drosophila flies suggesting that flies are the natural vectors of these microorganisms. PMID:24031324

  4. Membrane bioreactor wastewater treatment plants reveal diverse yeast and protist communities of potential significance in biofouling.

    PubMed

    Liébana, Raquel; Arregui, Lucía; Belda, Ignacio; Gamella, Luis; Santos, Antonio; Marquina, Domingo; Serrano, Susana

    2015-01-01

    The yeast community was studied in a municipal full-scale membrane bioreactor wastewater treatment plant (MBR-WWTP). The unexpectedly high diversity of yeasts indicated that the activated sludge formed a suitable environment for them to proliferate, with cellular concentrations of 2.2 ± 0.8 × 10(3) CFU ml(-1). Sixteen species of seven genera were present in the biological reactor, with Ascomycetes being the most prevalent group (93%). Most isolates were able to grow in a synthetic wastewater medium, adhere to polyethylene surfaces, and develop biofilms of variable complexity. The relationship between yeast populations and the protists in the MBR-WWTP was also studied, revealing that some protist species preyed on and ingested yeasts. These results suggest that yeast populations may play a role in the food web of a WWTP and, to some extent, contribute to membrane biofouling in MBR systems. PMID:25588128

  5. Population genomic analysis of outcrossing and recombination in yeast.

    PubMed

    Ruderfer, Douglas M; Pratt, Stephen C; Seidel, Hannah S; Kruglyak, Leonid

    2006-09-01

    The budding yeast Saccharomyces cerevisiae has been used by humans for millennia to make wine, beer and bread. More recently, it became a key model organism for studies of eukaryotic biology and for genomic analysis. However, relatively little is known about the natural lifestyle and population genetics of yeast. One major question is whether genetically diverse yeast strains mate and recombine in the wild. We developed a method to infer the evolutionary history of a species from genome sequences of multiple individuals and applied it to whole-genome sequence data from three strains of Saccharomyces cerevisiae and the sister species Saccharomyces paradoxus. We observed a pattern of sequence variation among yeast strains in which ancestral recombination events lead to a mosaic of segments with shared genealogy. Based on sequence divergence and the inferred median size of shared segments (approximately 2,000 bp), we estimated that although any two strains have undergone approximately 16 million cell divisions since their last common ancestor, only 314 outcrossing events have occurred during this time (roughly one every 50,000 divisions). Local correlations in polymorphism rates indicate that linkage disequilibrium in yeast should extend over kilobases. Our results provide the initial foundation for population studies of association between genotype and phenotype in S. cerevisiae. PMID:16892060

  6. Yeasts in table olive processing: desirable or spoilage microorganisms?

    PubMed

    Arroyo-López, F N; Romero-Gil, V; Bautista-Gallego, J; Rodríguez-Gómez, F; Jiménez-Díaz, R; García-García, P; Querol, A; Garrido-Fernández, A

    2012-11-01

    Yeasts are unicellular eukaryotic microorganisms isolated from many foods, and are commonly found in table olive processing where they can play a double role. On one hand, these microorganisms can produce spoilage of fruits due to the production of bad odours and flavours, the accumulation of CO(2) leading to swollen containers, the clouding of brines, the softening of fruits and the degradation of lactic acid, which is especially harmful during table olive storage and packaging. But on the other hand, fortunately, yeasts also possess desirable biochemical activities (lipase, esterase, β-glucosidase, catalase, production of killer factors, etc.) with important technological applications in this fermented vegetable. Recently, the probiotic potential of olive yeasts has begun to be evaluated because many species are able to resist the passage through the gastrointestinal tract and show beneficial effects on the host. In this way, yeasts may improve consumers' health by decreasing cholesterol levels, inhibiting pathogens, degrading non assimilated compounds, producing antioxidants and vitamins, adhering to intestinal cells or by maintaining epithelial barrier integrity. Many yeast species, usually also found in table olive processing, such as Wicherhamomyces anomalus, Saccharomyces cerevisiae, Pichia membranifaciens and Kluyveromyces lactis, have been reported to exhibit some of these properties. Thus, the selection of the most appropriate strains to be used as starters, alone or in combination with lactic acid bacteria, is a promising research line to develop in a near future which might improve the added value of the commercialized product. PMID:23141644

  7. [Automated method for yeast identification: ATB 32 C].

    PubMed

    Hernández-Molina, J M; Coque, M T; Campos, E; Rando, C; Leiva, E F

    1992-05-01

    The aim of this study was to evaluate the ATB 32 C (API system) automatic medium for identifying yeasts in clinical samples. A total of 101 yeasts strains were studied, representing 8 genera and 18 different species, identified by conventional means. All 32 microdomes of the track, including dehydrated substrates, were inoculated in a semi-solid media (C medium). After their incubation at 30 degrees C for 48 hours, the reading device ATB 1520 and the computer of ATB system the reading and automatic interpretation of the results. Using the ATB method, 85 strains were identified (84%) at species level, 9 at genus level and a non-conclusive or unacceptable profile was recorded in 7 strains. From all clinically important yeasts species, a total of 96% were identified by ATB method according to conventional methods. From all non clinically relevant species, ATB 32 C identified correctly 23 strains (78%). ATB 32 C method is a good alternative approach to conventional techniques for identifying yeasts in clinical samples. PMID:1391001

  8. Reclassification of ascomycetous yeasts from gene sequence analyses

    Technology Transfer Automated Retrieval System (TEKTRAN)

    During the past decade, identification of yeasts and their classification has been based almost exclusively on gene sequence analysis. Primarily as a result of using diagnostic gene sequences, such as D1/D2 LSU and ITS ribosomal RNAs, the number of known species has doubled. With the faster sequen...

  9. Responses of yeast biocontrol agents to environmental stress

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Biological control of postharvest diseases, utilizing wild species and strains of antagonistic yeasts, is a research topic that has received considerable attention in the literature over the past 30 years. In principle, it represents a promising alternative to chemical fungicides for the management...

  10. Trichosporon Species Isolated from Guano Samples Obtained from Bat-Inhabited Caves in Japan

    PubMed Central

    Sugita, Takashi; Kikuchi, Ken; Makimura, Koichi; Urata, Kensaku; Someya, Takashi; Kamei, Katsuhiko; Niimi, Masakazu; Uehara, Yoshimasa

    2005-01-01

    Yeasts from caves have rarely been examined. We examined yeasts collected from bat guano samples from 20 bat-inhabited limestone and volcanic caves located in 11 prefectures in Japan. Of ∼700 yeast-like colonies, nine Trichosporon species were recovered from 15 caves. Two of these were known species, and the remaining seven are potentially novel species, based on molecular phylogenetic analyses. In addition to Trichosporon species, identifiable strains of eight ascomycetous yeasts and one basidiomycetous yeast were recovered at frequencies of 5 to 35%. Our findings suggest that Trichosporon spp. are the major yeast species in bat guano in Japan and that bat guano is a potentially rich source of previously undescribed yeast species. PMID:16269819

  11. Transcriptional activators in yeast

    PubMed Central

    2006-01-01

    Eukaryotic transcription activation domains (ADs) are not well defined on the proteome scale. We systematicallly tested ∼6000 yeast proteins for transcriptional activity using a yeast one-hybrid system and identified 451 transcriptional activators. We then determined their transcription activation strength using fusions to the Gal4 DNA-binding domain and a His3 reporter gene which contained a promoter with a Gal4-binding site. Among the 132 strongest activators 32 are known transcription factors while another 35 have no known function. Although zinc fingers, helix–loop–helix domains and several other domains are highly overrepresented among the activators, only few contain characterized ADs. We also found some striking correlations: the stronger the activation activity, the more acidic, glutamine-rich, proline-rich or asparagine-rich the activators were. About 29% of the activators have been found previously to specifically interact with the transcription machinery, while 10% are known to be components of transcription regulatory complexes. Based on their transcriptional activity, localization and interaction patterns, at least six previously uncharacterized proteins are suggested to be bona fide transcriptional regulators (namely YFL049W, YJR070C, YDR520C, YGL066W/Sgf73, YKR064W and YCR082W/Ahc2). PMID:16464826

  12. The Trichoderma harzianum demon: complex speciation history resulting in coexistence of hypothetical biological species, recent agamospecies and numerous relict lineages

    PubMed Central

    2010-01-01

    Background The mitosporic fungus Trichoderma harzianum (Hypocrea, Ascomycota, Hypocreales, Hypocreaceae) is an ubiquitous species in the environment with some strains commercially exploited for the biological control of plant pathogenic fungi. Although T. harzianum is asexual (or anamorphic), its sexual stage (or teleomorph) has been described as Hypocrea lixii. Since recombination would be an important issue for the efficacy of an agent of the biological control in the field, we investigated the phylogenetic structure of the species. Results Using DNA sequence data from three unlinked loci for each of 93 strains collected worldwide, we detected a complex speciation process revealing overlapping reproductively isolated biological species, recent agamospecies and numerous relict lineages with unresolved phylogenetic positions. Genealogical concordance and recombination analyses confirm the existence of two genetically isolated agamospecies including T. harzianum sensu stricto and two hypothetical holomorphic species related to but different from H. lixii. The exact phylogenetic position of the majority of strains was not resolved and therefore attributed to a diverse network of recombining strains conventionally called 'pseudoharzianum matrix'. Since H. lixii and T. harzianum are evidently genetically isolated, the anamorph - teleomorph combination comprising H. lixii/T. harzianum in one holomorph must be rejected in favor of two separate species. Conclusions Our data illustrate a complex speciation within H. lixii - T. harzianum species group, which is based on coexistence and interaction of organisms with different evolutionary histories and on the absence of strict genetic borders between them. PMID:20359347

  13. [Study of animal viruses in yeast].

    PubMed

    Morikawa, Yuko

    2006-06-01

    Yeast is often considered to be a model eukaryotic organism, in a manner analogous to E. coli as a model prokaryotic organism. Yeast has been extensively characterized and the genomes completely sequenced. Despite the small genome size, yeast displays most of features of higher eukaryotes. The facts that most of cellular machinery is conserved among different eukaryotes and that the powerful technologies of genetics and molecular biology are available have made yeast model eukaryotic cells in biological and biomedical sciences including virology. Cumulative data indicate that yeast can be a host for animal viruses. I briefly describe yeast gene expression and review viral replication in yeast. Great discovery include complete replication of animal viruses and production of virus-like particle vaccines in yeast. Current studies on yeast focus on identification of host factors and machinery used for viral replication. The studies are based on traditional yeast genetics and genome-wide identification using a complete set of yeast deletion strains. PMID:17038807

  14. Yeast dynamics during spontaneous fermentation of mawè and tchoukoutou, two traditional products from Benin.

    PubMed

    Greppi, Anna; Rantisou, Kalliopi; Padonou, Wilfrid; Hounhouigan, Joseph; Jespersen, Lene; Jakobsen, Mogens; Cocolin, Luca

    2013-07-15

    Mawè and tchoukoutou are two traditional fermented foods largely consumed in Benin, West Africa. Their preparations remain as a house art and they are the result of spontaneous fermentation processes. In this study, dynamics of the yeast populations occurring during spontaneous fermentations of mawè and tchoukoutou were investigated using both culture-dependent and -independent approaches. For each product, two productions were followed. Samples were taken at different fermentation times and yeasts were isolated, resulting in the collection of 177 isolates. They were identified by the PCR-DGGE technique followed by the sequencing of the D1/D2 domain of the 26S rRNA gene. The predominant yeast species identified were typed by rep-PCR. Candida krusei was the predominant yeast species in mawè fermentation followed by Candida glabrata and Kluyveromyces marxianus. Other yeast species were detected in lower numbers. The yeast successions that took place during mawè fermentation lead to a final population comprising Saccharomyces cerevisiae, C. krusei and K. marxianus. The yeast populations dominating the fermentation of tchoukoutou were found to consist of S. cerevisiae, almost exclusively. Other yeast species were detected in the early stages of fermentation. For the predominant species a succession of biotypes was demonstrated by rep-PCR for the fermentation of both products. The direct analysis at DNA and RNA levels in the case of mawè did not reveal any other species except those already identified by culture-based analysis. On the other hand, for tchoukoutou, four species were identified that were not detected by the culture-based approach. The spontaneous fermentation of mawè and tchoukoutou in the end were dominated by a few autochthonous species. PMID:23756236

  15. Repeat-Associated Fission Yeast-Like Regional Centromeres in the Ascomycetous Budding Yeast Candida tropicalis

    PubMed Central

    Chatterjee, Gautam; Sankaranarayanan, Sundar Ram; Guin, Krishnendu; Thattikota, Yogitha; Padmanabhan, Sreedevi; Siddharthan, Rahul; Sanyal, Kaustuv

    2016-01-01

    The centromere, on which kinetochore proteins assemble, ensures precise chromosome segregation. Centromeres are largely specified by the histone H3 variant CENP-A (also known as Cse4 in yeasts). Structurally, centromere DNA sequences are highly diverse in nature. However, the evolutionary consequence of these structural diversities on de novo CENP-A chromatin formation remains elusive. Here, we report the identification of centromeres, as the binding sites of four evolutionarily conserved kinetochore proteins, in the human pathogenic budding yeast Candida tropicalis. Each of the seven centromeres comprises a 2 to 5 kb non-repetitive mid core flanked by 2 to 5 kb inverted repeats. The repeat-associated centromeres of C. tropicalis all share a high degree of sequence conservation with each other and are strikingly diverged from the unique and mostly non-repetitive centromeres of related Candida species—Candida albicans, Candida dubliniensis, and Candida lusitaniae. Using a plasmid-based assay, we further demonstrate that pericentric inverted repeats and the underlying DNA sequence provide a structural determinant in CENP-A recruitment in C. tropicalis, as opposed to epigenetically regulated CENP-A loading at centromeres in C. albicans. Thus, the centromere structure and its influence on de novo CENP-A recruitment has been significantly rewired in closely related Candida species. Strikingly, the centromere structural properties along with role of pericentric repeats in de novo CENP-A loading in C. tropicalis are more reminiscent to those of the distantly related fission yeast Schizosaccharomyces pombe. Taken together, we demonstrate, for the first time, fission yeast-like repeat-associated centromeres in an ascomycetous budding yeast. PMID:26845548

  16. Mechanisms of Chromosome Number Evolution in Yeast

    PubMed Central

    Gordon, Jonathan L.; Byrne, Kevin P.; Wolfe, Kenneth H.

    2011-01-01

    The whole-genome duplication (WGD) that occurred during yeast evolution changed the basal number of chromosomes from 8 to 16. However, the number of chromosomes in post-WGD species now ranges between 10 and 16, and the number in non-WGD species (Zygosaccharomyces, Kluyveromyces, Lachancea, and Ashbya) ranges between 6 and 8. To study the mechanism by which chromosome number changes, we traced the ancestry of centromeres and telomeres in each species. We observe only two mechanisms by which the number of chromosomes has decreased, as indicated by the loss of a centromere. The most frequent mechanism, seen 8 times, is telomere-to-telomere fusion between two chromosomes with the concomitant death of one centromere. The other mechanism, seen once, involves the breakage of a chromosome at its centromere, followed by the fusion of the two arms to the telomeres of two other chromosomes. The only mechanism by which chromosome number has increased in these species is WGD. Translocations and inversions have cycled telomere locations, internalizing some previously telomeric genes and creating novel telomeric locations. Comparison of centromere structures shows that the length of the CDEII region is variable between species but uniform within species. We trace the complete rearrangement history of the Lachancea kluyveri genome since its common ancestor with Saccharomyces and propose that its exceptionally low level of rearrangement is a consequence of the loss of the non-homologous end joining (NHEJ) DNA repair pathway in this species. PMID:21811419

  17. Local climatic conditions constrain soil yeast diversity patterns in Mediterranean forests, woodlands and scrub biome.

    PubMed

    Yurkov, Andrey M; Röhl, Oliver; Pontes, Ana; Carvalho, Cláudia; Maldonado, Cristina; Sampaio, José Paulo

    2016-02-01

    Soil yeasts represent a poorly known fraction of the soil microbiome due to limited ecological surveys. Here, we provide the first comprehensive inventory of cultivable soil yeasts in a Mediterranean ecosystem, which is the leading biodiversity hotspot for vascular plants and vertebrates in Europe. We isolated and identified soil yeasts from forested sites of Serra da Arrábida Natural Park (Portugal), representing the Mediterranean forests, woodlands and scrub biome. Both cultivation experiments and the subsequent species richness estimations suggest the highest species richness values reported to date, resulting in a total of 57 and 80 yeast taxa, respectively. These values far exceed those reported for other forest soils in Europe. Furthermore, we assessed the response of yeast diversity to microclimatic environmental factors in biotopes composed of the same plant species but showing a gradual change from humid broadleaf forests to dry maquis. We observed that forest properties constrained by precipitation level had strong impact on yeast diversity and on community structure and lower precipitation resulted in an increased number of rare species and decreased evenness values. In conclusion, the structure of soil yeast communities mirrors the environmental factors that affect aboveground phytocenoses, aboveground biomass and plant projective cover. PMID:26568202

  18. Oleaginous yeasts for biodiesel: current and future trends in biology and production.

    PubMed

    Sitepu, Irnayuli R; Garay, Luis A; Sestric, Ryan; Levin, David; Block, David E; German, J Bruce; Boundy-Mills, Kyria L

    2014-11-15

    Production of biodiesel from edible plant oils is quickly expanding worldwide to fill a need for renewable, environmentally-friendly liquid transportation fuels. Due to concerns over use of edible commodities for fuels, production of biodiesel from non-edible oils including microbial oils is being developed. Microalgae biodiesel is approaching commercial viability, but has some inherent limitations such as requirements for sunlight. While yeast oils have been studied for decades, recent years have seen significant developments including discovery of new oleaginous yeast species and strains, greater understanding of the metabolic pathways that determine oleaginicity, optimization of cultivation processes for conversion of various types of waste plant biomass to oil using oleaginous yeasts, and development of strains with enhanced oil production. This review examines aspects of oleaginous yeasts not covered in depth in other recent reviews. Topics include the history of oleaginous yeast research, especially advances in the early 20th century; the phylogenetic diversity of oleaginous species, beyond the few species commonly studied; and physiological characteristics that should be considered when choosing yeast species and strains to be utilized for conversion of a given type of plant biomass to oleochemicals. Standardized terms are proposed for units that describe yeast cell mass and lipid production. PMID:25172033

  19. Horizontal Transfer of Genetic Material among Saccharomyces Yeasts

    PubMed Central

    Marinoni, Gaelle; Manuel, Martine; Petersen, Randi Føns; Hvidtfeldt, Jeanne; Sulo, Pavol; Piškur, Jure

    1999-01-01

    The genus Saccharomyces consists of several species divided into the sensu stricto and the sensu lato groups. The genomes of these species differ in the number and organization of nuclear chromosomes and in the size and organization of mitochondrial DNA (mtDNA). In the present experiments we examined whether these yeasts can exchange DNA and thereby create novel combinations of genetic material. Several putative haploid, heterothallic yeast strains were isolated from different Saccharomyces species. All of these strains secreted an a- or α-like pheromone recognized by S. cerevisiae tester strains. When interspecific crosses were performed by mass mating between these strains, hybrid zygotes were often detected. In general, the less related the two parental species were, the fewer hybrids they gave. For some crosses, viable hybrids could be obtained by selection on minimal medium and their nuclear chromosomes and mtDNA were examined. Often the frequency of viable hybrids was very low. Sometimes putative hybrids could not be propagated at all. In the case of sensu stricto yeasts, stable viable hybrids were obtained. These contained both parental sets of chromosomes but mtDNA from only one parent. In the case of sensu lato hybrids, during genetic stabilization one set of the parental chromosomes was partially or completely lost and the stable mtDNA originated from the same parent as the majority of the nuclear chromosomes. Apparently, the interspecific hybrid genome was genetically more or less stable when the genetic material originated from phylogenetically relatively closely related parents; both sets of nuclear genetic material could be transmitted and preserved in the progeny. In the case of more distantly related parents, only one parental set, and perhaps some fragments of the other one, could be found in genetically stabilized hybrid lines. The results obtained indicate that Saccharomyces yeasts have a potential to exchange genetic material. If Saccharomyces

  20. Genetic Interactions Between Transcription Factors Cause Natural Variation in Yeast

    PubMed Central

    Gerke, Justin; Lorenz, Kim; Cohen, Barak

    2016-01-01

    Our understanding of the genetic basis of phenotypic diversity is limited by the paucity of examples in which multiple, interacting loci have been identified. We show that natural variation in the efficiency of sporulation, the program in yeast that initiates the sexual phase of the life cycle, between oak tree and vineyard strains is due to allelic variation between four nucleotide changes in three transcription factors: IME1, RME1, and RSF1. Furthermore, we identified that selection has shaped quantitative variation in yeast sporulation between strains. These results illustrate how genetic interactions between transcription factors are a major source of phenotypic diversity within species. PMID:19164747

  1. Fermentation of xylulose to ethanol using xylose isomerase and yeasts

    SciTech Connect

    Jeffries, T.W.

    1981-01-01

    In a survey of 35 organisms, predominantly yeasts, about 40% were capable of fermenting xylulose to ethanol. Two species, Candida tropicalis and Schizosaccharomyces pombe, did so at good rates and without an initial lag. Saccharomyces cerevisiae strains that fermented glucose rapidly fermented xylulose at a slower rate. Ten yeasts and three strains of the bacterium Zymomonas mobilis were weak or negative for xylulose, even though they fermented glucose under the conditions employed. C. tropicalis was able to form 1.0 M ethanol from 1.0 M xylose if the fermentation broth was recycled over immobilized xylose isomerase.

  2. Utilization of hexamethylenetetramine (urotropine) by bacteria and yeasts.

    PubMed

    Middelhoven, Wouter J; van Doesburg, Wim

    2007-02-01

    A slow growing bacterial population able to utilize hexamethylelenetetramine (urotropine) as sole source of carbon, nitrogen and energy was isolated from soil. From this crude enrichment culture two bacteria were isolated and identified as Brevundimonas diminuta and a Phyllobacterium sp. by sequencing of 16S ribosomal DNA. These bacteria also grew on urotropine but at a lower rate than the enrichment culture. Addition of glucose to the latter resulted in growth of some yeasts that overgrew the bacteria. Assimilation of urotropine as sole nitrogen source is very common among yeasts, 46 out of 60 species tested showed this characteristic. PMID:17043911

  3. Interaction Between Yeasts and Zinc

    NASA Astrophysics Data System (ADS)

    Nicola, Raffaele De; Walker, Graeme

    Zinc is an essential trace element in biological systems. For example, it acts as a cellular membrane stabiliser, plays a critical role in gene expression and genome modification and activates nearly 300 enzymes, including alcohol dehydrogenase. The present chapter will be focused on the influence of zinc on cell physiology of industrial yeast strains of Saccharomyces cerevisiae, with special regard to the uptake and subsequent utilisation of this metal. Zinc uptake by yeast is metabolism-dependent, with most of the available zinc translocated very quickly into the vacuole. At cell division, zinc is distributed from mother to daughter cells and this effectively lowers the individual cellular zinc concentration, which may become zinc depleted at the onset of the fermentation. Zinc influences yeast fermentative performance and examples will be provided relating to brewing and wine fermentations. Industrial yeasts are subjected to several stresses that may impair fermentation performance. Such stresses may also impact on yeast cell zinc homeostasis. This chapter will discuss the practical implications for the correct management of zinc bioavailability for yeast-based biotechnologies aimed at improving yeast growth, viability, fermentation performance and resistance to environmental stresses

  4. Yeasts: From genetics to biotechnology

    SciTech Connect

    Russo, S.; Poli, G.; Siman-Tov, R.B.

    1995-12-31

    Yeasts have been known and used in food and alcoholic fermentations ever since the Neolithic Age. In more recent times, on the basis of their peculiar features and history, yeasts have become very important experimental models in both microbiological and genetic research, as well as the main characters in many fermentative production processes. In the last 40 years, advances in molecular biology and genetic engineering have made possible not only the genetic selection of organisms, but also the genetic modification of some of them, especially the simplest of them, such as bacteria and yeasts. These discoveries have led to the availability of new yeast strains fit to fulfill requests of industrial production and fermentation. Moreover, genetically modified and transformed yeasts have been constructed that are able to produce large amounts of biologically active proteins and enzymes. Thus, recombinant yeasts make it easier to produce drugs, biologically active products, diagnostics, and vaccines, by inexpensive and relatively simple techniques. Yeasts are going to become more and more important in the {open_quotes}biotechnological revolution{close_quotes} by virtue of both their features and their very long and safe use in human nutrition and industry. 175 refs., 4 figs., 6 tabs.

  5. Fission yeast septation

    PubMed Central

    Cortés, Juan C. G.; Ramos, Mariona; Osumi, Masako; Pérez, Pilar; Ribas, Juan Carlos

    2016-01-01

    ABSTRACT In animal cells cytokinesis relies on the contraction of an actomyosin ring that pulls the plasma membrane to create a cleavage furrow, whose ingression finally divides the mother cell into two daughter cells. Fungal cells are surrounded by a tough and flexible structure called cell wall, which is considered to be the functional equivalent of the extracellular matrix in animal cells. Therefore, in addition to cleavage furrow ingression, fungal cytokinesis also requires the centripetal formation of a septum wall structure that develops between the dividing cells, whose genesis must be strictly coordinated with both the actomyosin ring closure and plasma membrane ingression. Here we briefly review what is known about the septum structure and composition in the fission yeast Schizosaccharomyces pombe, the recent progress about the relationship between septum biosynthesis and actomyosin ring constriction, and the importance of the septum and ring in the steady progression of the cleavage furrow. PMID:27574536

  6. Fission yeast septation.

    PubMed

    Cortés, Juan C G; Ramos, Mariona; Osumi, Masako; Pérez, Pilar; Ribas, Juan Carlos

    2016-01-01

    In animal cells cytokinesis relies on the contraction of an actomyosin ring that pulls the plasma membrane to create a cleavage furrow, whose ingression finally divides the mother cell into two daughter cells. Fungal cells are surrounded by a tough and flexible structure called cell wall, which is considered to be the functional equivalent of the extracellular matrix in animal cells. Therefore, in addition to cleavage furrow ingression, fungal cytokinesis also requires the centripetal formation of a septum wall structure that develops between the dividing cells, whose genesis must be strictly coordinated with both the actomyosin ring closure and plasma membrane ingression. Here we briefly review what is known about the septum structure and composition in the fission yeast Schizosaccharomyces pombe, the recent progress about the relationship between septum biosynthesis and actomyosin ring constriction, and the importance of the septum and ring in the steady progression of the cleavage furrow. PMID:27574536

  7. Quantifying Variation in the Ability of Yeasts to Attract Drosophila melanogaster

    PubMed Central

    Palanca, Loida; Gaskett, Anne C.; Günther, Catrin S.; Newcomb, Richard D.; Goddard, Matthew R.

    2013-01-01

    Yeasts that invade and colonise fruit significantly enhance the volatile chemical diversity of this ecosystem. These modified bouquets are thought to be more attractive to Drosophila flies than the fruit alone, but the variance of attraction in natural yeast populations is uncharacterised. Here we investigate how a range of yeast isolates affect the attraction of female D. melanogaster to fruit in a simple two choice assay comparing yeast to sterile fruit. Of the 43 yeast isolates examined, 33 were attractive and seven repellent to the flies. The results of isolate-versus-isolate comparisons provided the same relative rankings. Attractiveness varied significantly by yeast, with the strongly fermenting Saccharomyces species generally being more attractive than the mostly respiring non-Saccharomyces species (P = 0.0035). Overall the habitat (fruit or other) from which the isolates were directly sampled did not explain attraction (P = 0.2352). However, yeasts isolated from fruit associated niches were more attractive than those from non-fruit associated niches (P = 0.0188) regardless of taxonomic positioning. These data suggest that while attractiveness is primarily correlated with phylogenetic status, the ability to attract Drosophila is a labile trait among yeasts that is potentially associated with those inhabiting fruit ecosystems. Preliminary analysis of the volatiles emitted by four yeast isolates in grape juice show the presence/absence of ethanol and acetic acid were not likely explanations for the observed variation in attraction. These data demonstrate variation among yeasts for their ability to attract Drosophila in a pattern that is consistent with the hypothesis that certain yeasts are manipulating fruit odours to mediate interactions with their Drosophila dispersal agent. PMID:24086510

  8. Quantifying variation in the ability of yeasts to attract Drosophila melanogaster.

    PubMed

    Palanca, Loida; Gaskett, Anne C; Günther, Catrin S; Newcomb, Richard D; Goddard, Matthew R

    2013-01-01

    Yeasts that invade and colonise fruit significantly enhance the volatile chemical diversity of this ecosystem. These modified bouquets are thought to be more attractive to Drosophila flies than the fruit alone, but the variance of attraction in natural yeast populations is uncharacterised. Here we investigate how a range of yeast isolates affect the attraction of female D. melanogaster to fruit in a simple two choice assay comparing yeast to sterile fruit. Of the 43 yeast isolates examined, 33 were attractive and seven repellent to the flies. The results of isolate-versus-isolate comparisons provided the same relative rankings. Attractiveness varied significantly by yeast, with the strongly fermenting Saccharomyces species generally being more attractive than the mostly respiring non-Saccharomyces species (P = 0.0035). Overall the habitat (fruit or other) from which the isolates were directly sampled did not explain attraction (P = 0.2352). However, yeasts isolated from fruit associated niches were more attractive than those from non-fruit associated niches (P = 0.0188) regardless of taxonomic positioning. These data suggest that while attractiveness is primarily correlated with phylogenetic status, the ability to attract Drosophila is a labile trait among yeasts that is potentially associated with those inhabiting fruit ecosystems. Preliminary analysis of the volatiles emitted by four yeast isolates in grape juice show the presence/absence of ethanol and acetic acid were not likely explanations for the observed variation in attraction. These data demonstrate variation among yeasts for their ability to attract Drosophila in a pattern that is consistent with the hypothesis that certain yeasts are manipulating fruit odours to mediate interactions with their Drosophila dispersal agent. PMID:24086510

  9. 21 CFR 172.896 - Dried yeasts.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 3 2012-04-01 2012-04-01 false Dried yeasts. 172.896 Section 172.896 Food and... Multipurpose Additives § 172.896 Dried yeasts. Dried yeast (Saccharomyces cerevisiae and Saccharomyces fragilis) and dried torula yeast (Candida utilis) may be safely used in food provided the total folic...

  10. 21 CFR 172.896 - Dried yeasts.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 3 2011-04-01 2011-04-01 false Dried yeasts. 172.896 Section 172.896 Food and... Multipurpose Additives § 172.896 Dried yeasts. Dried yeast (Saccharomyces cerevisiae and Saccharomyces fragilis) and dried torula yeast (Candida utilis) may be safely used in food provided the total folic...

  11. 21 CFR 172.896 - Dried yeasts.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Dried yeasts. 172.896 Section 172.896 Food and... Multipurpose Additives § 172.896 Dried yeasts. Dried yeast (Saccharomyces cerevisiae and Saccharomyces fragilis) and dried torula yeast (Candida utilis) may be safely used in food provided the total folic...

  12. 21 CFR 172.896 - Dried yeasts.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 3 2014-04-01 2014-04-01 false Dried yeasts. 172.896 Section 172.896 Food and... PERMITTED FOR DIRECT ADDITION TO FOOD FOR HUMAN CONSUMPTION Multipurpose Additives § 172.896 Dried yeasts. Dried yeast (Saccharomyces cerevisiae and Saccharomyces fragilis) and dried torula yeast (Candida...

  13. 21 CFR 172.896 - Dried yeasts.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 3 2013-04-01 2013-04-01 false Dried yeasts. 172.896 Section 172.896 Food and... Multipurpose Additives § 172.896 Dried yeasts. Dried yeast (Saccharomyces cerevisiae and Saccharomyces fragilis) and dried torula yeast (Candida utilis) may be safely used in food provided the total folic...

  14. Yeast Biodiversity in Vineyard Environments Is Increased by Human Intervention.

    PubMed

    Drumonde-Neves, João; Franco-Duarte, Ricardo; Lima, Teresa; Schuller, Dorit; Pais, Célia

    2016-01-01

    One hundred and five grape samples were collected during two consecutive years from 33 locations on seven oceanic islands of the Azores Archipelago. Grape samples were obtained from vineyards that were either abandoned or under regular cultivation involving common viticultural interventions, to evaluate the impact of regular human intervention on grape yeast biota diversity in vineyards. A total of 3150 yeast isolates were obtained and 23 yeast species were identified. The predominant species were Hanseniaspora uvarum, Pichia terricola, Starmerella bacillaris and Issatchenkia hanoiensis. The species Barnettozyma californica, Candida azymoides and Pichia cecembensis were reported in grapes or wine-associated environments for the first time. A higher biodiversity was found in active vineyards where regular human intervention takes place (Shannon index: 1.89 and 1.53 in the first and second years, respectively) when compared to the abandoned ones (Shannon index: 0.76 and 0.31). This finding goes against the assumptions that human intervention can destroy biodiversity and lead to homogeneity in the environment. Biodiversity indices were considerably lower in the year with the heaviest rainfall. This study is the first to report on the grape yeast communities from several abandoned vineyards that have undergone no human intervention. PMID:27500638

  15. Yeast Biodiversity in Vineyard Environments Is Increased by Human Intervention

    PubMed Central

    Drumonde-Neves, João; Lima, Teresa; Schuller, Dorit; Pais, Célia

    2016-01-01

    One hundred and five grape samples were collected during two consecutive years from 33 locations on seven oceanic islands of the Azores Archipelago. Grape samples were obtained from vineyards that were either abandoned or under regular cultivation involving common viticultural interventions, to evaluate the impact of regular human intervention on grape yeast biota diversity in vineyards. A total of 3150 yeast isolates were obtained and 23 yeast species were identified. The predominant species were Hanseniaspora uvarum, Pichia terricola, Starmerella bacillaris and Issatchenkia hanoiensis. The species Barnettozyma californica, Candida azymoides and Pichia cecembensis were reported in grapes or wine-associated environments for the first time. A higher biodiversity was found in active vineyards where regular human intervention takes place (Shannon index: 1.89 and 1.53 in the first and second years, respectively) when compared to the abandoned ones (Shannon index: 0.76 and 0.31). This finding goes against the assumptions that human intervention can destroy biodiversity and lead to homogeneity in the environment. Biodiversity indices were considerably lower in the year with the heaviest rainfall. This study is the first to report on the grape yeast communities from several abandoned vineyards that have undergone no human intervention. PMID:27500638

  16. The Spontaneous Mutation Rate in the Fission Yeast Schizosaccharomyces pombe.

    PubMed

    Farlow, Ashley; Long, Hongan; Arnoux, Stéphanie; Sung, Way; Doak, Thomas G; Nordborg, Magnus; Lynch, Michael

    2015-10-01

    The rate at which new mutations arise in the genome is a key factor in the evolution and adaptation of species. Here we describe the rate and spectrum of spontaneous mutations for the fission yeast Schizosaccharomyces pombe, a key model organism with many similarities to higher eukaryotes. We undertook an ∼1700-generation mutation accumulation (MA) experiment with a haploid S. pombe, generating 422 single-base substitutions and 119 insertion-deletion mutations (indels) across the 96 replicates. This equates to a base-substitution mutation rate of 2.00 × 10(-10) mutations per site per generation, similar to that reported for the distantly related budding yeast Saccharomyces cerevisiae. However, these two yeast species differ dramatically in their spectrum of base substitutions, the types of indels (S. pombe is more prone to insertions), and the pattern of selection required to counteract a strong AT-biased mutation rate. Overall, our results indicate that GC-biased gene conversion does not play a major role in shaping the nucleotide composition of the S. pombe genome and suggest that the mechanisms of DNA maintenance may have diverged significantly between fission and budding yeasts. Unexpectedly, CpG sites appear to be excessively liable to mutation in both species despite the likely absence of DNA methylation. PMID:26265703

  17. Yeasts associated with an abandoned mining area in Pernek and their tolerance to different chemical elements.

    PubMed

    Vadkertiová, Renáta; Molnárová, Jana; Lux, Alexander; Vaculík, Marek; Lišková, Desana

    2016-05-01

    Four plants, Cirsium arvense (creeping thistle), Equisetum arvense (field horsetail), Oxalis acetosella (wood sorrel) and Phragmites australis (common reed), which grew in an abandoned Sb-mining area in Pernek (Malé Karpaty Mts., Slovakia), were investigated for the yeast species. Yeasts were isolated from both the leaves of the plants and the soil adjacent to the plants. In total, 65 yeast cultures, belonging to 11 ascomycetous and 5 basidiomycetous yeast species, were isolated. The species most frequently isolated from both the soil and leaf samples were Trichosporon porosum, Galactomyces candidus and Candida solani, whereas Aureobasidium pullulans, Candida tsuchiyae and Sporidiobolus metaroseus were isolated exclusively from the plant leaves. All the yeast species isolated were tested for their tolerance to two heavy metals (Cd, Zn) and three metalloids (As, Sb and Si). The yeasts isolated from both the leaves and soils exhibited a high tolerance level to both As and Sb, present in elevated concentrations at the locality. Among the yeast species tested, Cryptococcus musci, a close relative to Cryptococcus humicola, was the species most tolerant to all the chemical elements tested, with the exception of Si. It grew in the presence of 200 mmol/L Zn, 200 mmol/L Cd, 60 mmol/L As and 50 mmol/L Sb, and therefore, it can be considered as a multi-tolerant species. Some of the yeast species were tolerant to the individual chemical elements. The yeast-like species Trichosporon laibachii exhibited the highest tolerance to Si of all yeasts tested, and Cryptococcus flavescens and Lindnera saturnus showed the same tolerance as Cryptococcus musci to Zn and As, respectively. The majority of the yeasts showed a notably low tolerance to Cd (not exceeded 0.5 mmol/L), which was present in small amounts in the soil. However, Candida solani, isolated from the soil, exhibited a higher tolerance to Cd (20 mmol/L) than to As (2 mmol/L). PMID:26358066

  18. Molecular Phylogeny of the Yeasts: Impact on Classification and Prediction of Biotechnological Properties

    Technology Transfer Automated Retrieval System (TEKTRAN)

    DNA sequence analysis and other DNA-based methodologies have transformed the way in which yeasts are identified and classified. Development of species-specific gene sequence databases has provided a barcode system for rapid identification of known species and the recognition of undescribed species. ...

  19. A few shared up-regulated genes may influence conidia to yeast transformation in dimorphic fungal pathogens.

    PubMed

    Kirkland, Theo N

    2016-08-01

    The small number of fungi that commonly cause disease in normal people share the capacity to grow as mycelia in the soil at 25°C and as yeast (or spherules) in mammals at 37°C. This remarkable conversion has long been a topic of interest in medical mycology. The conidia to yeast conversion has been studied by transcription profiling in several fungal species, including Histoplasma capsulatum, Paracoccidioides brasiliensis, Coccidioides spp., Blastomyces dermatitidis, and Talaromyces marneffei One limitation of transcriptional profiling is determining which genes are involved in the process of conversion to yeast as opposed to a result of conversion to yeast. If there are genes that are up-regulated in the yeast phase of more than one dimorphic, pathogenic fungus they might be required for conversion to yeast (or spherules). To address this issue, 24 up-regulated genes common to Coccidioides spp spherules and H. capsulatum yeasts were identified. Four homologs of these genes were also found in P. brasiliensis, B. dermatitidis or T. marneffei genes that were up-regulated in yeast. 4-hydroxyphenylpurvate dioxygenase, a gene involved in tyrosine metabolism and melanin synthesis that has been shown to be required for yeast conversion, is conserved and up-regulated in yeast in all five species. Another up-regulated gene that is conserved in all five species is a MFS sugar porter. These results suggest that a minority of up-regulated yeast (or spherule) genes are conserved across species and raises the possibility that conserved up-regulated genes may be of special interest for differentiation of mycelium into yeast. PMID:27118798

  20. Indole-3-Acetic Acid-Producing Yeasts in the Phyllosphere of the Carnivorous Plant Drosera indica L

    PubMed Central

    Shin, Li-Ying; Wei, Jyuan-Yu; Fu, Shih-Feng; Chou, Jui-Yu

    2014-01-01

    Yeasts are widely distributed in nature and exist in association with other microorganisms as normal inhabitants of soil, vegetation, and aqueous environments. In this study, 12 yeast strains were enriched and isolated from leaf samples of the carnivorous plant Drosera indica L., which is currently threatened because of restricted habitats and use in herbal industries. According to similarities in large subunit and small subunit ribosomal RNA gene sequences, we identified 2 yeast species in 2 genera of the phylum Ascomycota, and 5 yeast species in 5 genera of the phylum Basidiomycota. All of the isolated yeasts produced indole-3-acetic acid (IAA) when cultivated in YPD broth supplemented with 0.1% L-tryptophan. Growth conditions, such as the pH and temperature of the medium, influenced yeast IAA production. Our results also suggested the existence of a tryptophan-independent IAA biosynthetic pathway. We evaluated the effects of various concentrations of exogenous IAA on yeast growth and observed that IAA produced by wild yeasts modifies auxin-inducible gene expression in Arabidopsis. Our data suggest that yeasts can promote plant growth and support ongoing prospecting of yeast strains for inclusion into biofertilizer for sustainable agriculture. PMID:25464336

  1. Indole-3-acetic acid-producing yeasts in the phyllosphere of the carnivorous plant Drosera indica L.

    PubMed

    Sun, Pei-Feng; Fang, Wei-Ta; Shin, Li-Ying; Wei, Jyuan-Yu; Fu, Shih-Feng; Chou, Jui-Yu

    2014-01-01

    Yeasts are widely distributed in nature and exist in association with other microorganisms as normal inhabitants of soil, vegetation, and aqueous environments. In this study, 12 yeast strains were enriched and isolated from leaf samples of the carnivorous plant Drosera indica L., which is currently threatened because of restricted habitats and use in herbal industries. According to similarities in large subunit and small subunit ribosomal RNA gene sequences, we identified 2 yeast species in 2 genera of the phylum Ascomycota, and 5 yeast species in 5 genera of the phylum Basidiomycota. All of the isolated yeasts produced indole-3-acetic acid (IAA) when cultivated in YPD broth supplemented with 0.1% L-tryptophan. Growth conditions, such as the pH and temperature of the medium, influenced yeast IAA production. Our results also suggested the existence of a tryptophan-independent IAA biosynthetic pathway. We evaluated the effects of various concentrations of exogenous IAA on yeast growth and observed that IAA produced by wild yeasts modifies auxin-inducible gene expression in Arabidopsis. Our data suggest that yeasts can promote plant growth and support ongoing prospecting of yeast strains for inclusion into biofertilizer for sustainable agriculture. PMID:25464336

  2. Marine yeast isolation and industrial application

    PubMed Central

    Zaky, Abdelrahman Saleh; Tucker, Gregory A; Daw, Zakaria Yehia; Du, Chenyu

    2014-01-01

    Over the last century, terrestrial yeasts have been widely used in various industries, such as baking, brewing, wine, bioethanol and pharmaceutical protein production. However, only little attention has been given to marine yeasts. Recent research showed that marine yeasts have several unique and promising features over the terrestrial yeasts, for example higher osmosis tolerance, higher special chemical productivity and production of industrial enzymes. These indicate that marine yeasts have great potential to be applied in various industries. This review gathers the most recent techniques used for marine yeast isolation as well as the latest applications of marine yeast in bioethanol, pharmaceutical and enzyme production fields. PMID:24738708

  3. Yeast ABC transporters in lipid trafficking.

    PubMed

    Prasad, Rajendra; Khandelwal, Nitesh Kumar; Banerjee, Atanu

    2016-08-01

    Throughout its evolution, the ATP-binding cassette (ABC) transporter superfamily has experienced a rapid expansion in its substrate repertoire and functions. Of the diverse functions that these pumps offer, their drug transport properties have attracted considerable attention primarily owing to their clinical significance. Despite this fact, emerging evidence suggests that physiological substrates of transporters also affect the overall functioning of an organism. Lipids, as substrates of ABC transporters, constitute one feature found in all representative groups of the living kingdom. Due to the importance of lipid species in the cellular physiology of an organism, their proper distribution within cells is crucial. This fact is well exemplified by the vast number of medical conditions that have been caused as a result of perturbations in ABC transporter-mediated lipid transport in higher organisms. In yeasts, apart from providing transport functions, ABC transporters also coordinate regulatory networks with lipids. This review focuses on yeast ABC transporters involved in the transport of lipids and briefly discusses the integration of their regulatory network with that of the lipid species. PMID:27259587

  4. The seasonal dynamics of yeast communities in the rhizosphere of soddy-podzolic soils

    NASA Astrophysics Data System (ADS)

    Golubtsova, Yu. V.; Glushakova, A. M.; Chernov, I. Yu.

    2007-08-01

    The annual dynamics of the number and taxonomic composition of yeast was studied in the rhizosphere of two plant species (Ajuga reptans L. and Taraxacum officinale Wigg.) in a forb-birch forest on soddy-podzolic soil. Eurybiont phyllobasidial cryptococci and red-pigmented phytobionts Rhodotorula glutinis were found to predominate in the phyllosphere of these plants, whereas the typical pedobionts Cryptococcus terricola and Cr. podzolicus occurred on the surface of roots and in the rhizosphere. The seasonal changes in the number and species composition of the yeast communities in the rhizosphere were more smooth as compared to those in the phyllosphere. In the period of active vegetation of the plants, the phytobiont yeasts develop over their whole surface, including the rhizoplane. Their number on the aboveground parts of the plants was significantly lower than that of the pedobiont forms. Thus, the above-and underground parts of the plants significantly differed in the composition of the dominant species of epiphytic yeasts.

  5. Short Synthetic Terminators for Improved Heterologous Gene Expression in Yeast.

    PubMed

    Curran, Kathleen A; Morse, Nicholas J; Markham, Kelly A; Wagman, Allison M; Gupta, Akash; Alper, Hal S

    2015-07-17

    Terminators play an important role both in completing the transcription process and impacting mRNA half-life. As such, terminators are an important synthetic component considered in applications such as heterologous gene expression and metabolic engineering. Here, we describe a panel of short (35-70 bp) synthetic terminators that can be used for modulating gene expression in yeast. The best of these synthetic terminator resulted in 3.7-fold more fluorescent protein output and 4.4-fold increase in transcript level compared to that with the commonly used CYC1 terminator. These synthetic terminators offer several advantages over native sequences, including an easily synthesized short length, minimal sequence homology to native sequences, and similar or better performance characteristics than those of commonly used longer terminators. Furthermore, the synthetic terminators are highly functional in both Saccharomyces cerevisiae and an alternative yeast, Yarrowia lipolytica, demonstrating that these synthetic designs are transferrable between diverse yeast species. PMID:25686303

  6. Diversity and adaptive evolution of Saccharomyces wine yeast: a review

    PubMed Central

    Marsit, Souhir; Dequin, Sylvie

    2015-01-01

    Saccharomyces cerevisiae and related species, the main workhorses of wine fermentation, have been exposed to stressful conditions for millennia, potentially resulting in adaptive differentiation. As a result, wine yeasts have recently attracted considerable interest for studying the evolutionary effects of domestication. The widespread use of whole-genome sequencing during the last decade has provided new insights into the biodiversity, population structure, phylogeography and evolutionary history of wine yeasts. Comparisons between S. cerevisiae isolates from various origins have indicated that a variety of mechanisms, including heterozygosity, nucleotide and structural variations, introgressions, horizontal gene transfer and hybridization, contribute to the genetic and phenotypic diversity of S. cerevisiae. This review will summarize the current knowledge on the diversity and evolutionary history of wine yeasts, focusing on the domestication fingerprints identified in these strains. PMID:26205244

  7. Debaryomyces hansenii: An Osmotolerant and Halotolerant Yeast

    NASA Astrophysics Data System (ADS)

    Aggarwal, Monika; Mondal, Alok K.

    The yeast Debaryomyces hansenii which was isolated from saline environments such as sea water, concentrated brines, salty food, is one of the most halotolerant species. It can grow in media containing as high as 4 M NaCl, while the growth of Saccharomyces cerevisiae is limited in media with more than 1.7 M NaCl. This species is very important for food industry as it is used for surface ripening of cheese and meat products. In the recent past, there is growing interest in understanding the molecular mechanisms of high halotolerance exhibited by D. hansenii. Availability of genome sequence of D. hansenii has opened up new vistas in this direction

  8. Nectar yeasts in the tall Larkspur Delphinium barbeyi (Ranunculaceae) and effects on components of pollinator foraging behavior.

    PubMed

    Schaeffer, Robert N; Phillips, Cody R; Duryea, M Catherine; Andicoechea, Jonathan; Irwin, Rebecca E

    2014-01-01

    Microorganisms frequently colonize the nectar of angiosperm species. Though capable of altering a suite of traits important for pollinator attraction, few studies exist that test the degree to which they mediate pollinator foraging behavior. The objective of our study was to fill this gap by assessing the abundance and diversity of yeasts associated with the perennial larkspur Delphinium barbeyi (Ranunculaceae) and testing whether their presence affected components of pollinator foraging behavior. Yeasts frequently colonized D. barbeyi nectar, populating 54-77% of flowers examined depending on site. Though common, the yeast community was species-poor, represented by a single species, Metschnikowia reukaufii. Female-phase flowers of D. barbeyi were more likely to have higher densities of yeasts in comparison to male-phase flowers. Pollinators were likely vectors of yeasts, as virgin (unvisited) flowers rarely contained yeasts compared to flowers open to pollinator visitation, which were frequently colonized. Finally, pollinators responded positively to the presence of yeasts. Bombus foragers both visited and probed more flowers inoculated with yeasts in comparison to uninoculated controls. Taken together, our results suggest that variation in the occurrence and density of nectar-inhabiting yeasts have the potential to alter components of pollinator foraging behavior linked to pollen transfer and plant fitness. PMID:25272164

  9. Assessment of endophytic yeast diversity in rice leaves by a culture-independent approach.

    PubMed

    Tantirungkij, Manee; Nasanit, Rujikan; Limtong, Savitree

    2015-09-01

    Endophytic microorganisms inhabit internal plant tissues in the host plant without causing any symptoms or negative effects. Although the diversity of endophytes has been evaluated by both culture-dependent and culture-independent methods, less information is available on yeast communities. Therefore, in this study a culture-independent method was used to examine endophytic yeasts associated with rice leaves based on the large subunit of ribosomal DNA using a semi-nested PCR technique. Sequence analysis indicated that the colonization frequency and the relative species frequency (RF) of endophytic yeast phylotypes were 0.41 and 0.06, respectively, and the majority of the yeast phylotypes were basidiomycetous yeasts. The phylotypes were designated as five known species (Cryptococcus victoriae, Debaryomyces hansenii, Debaryomyces vindobonensis, Meyerozyma guilliermondii and Pseudozyma antarctica), together with seventeen phylotypes closest to Candida metapsilosis, Cryp. foliicola, Cryp. laurentii, Pseudozyma abaconensis, Pseudozyma aphidis and Trichosporon asahii, among which some could be novel species. The most prevalent phylotypes were those closest to Cryp. foliicola (47.5 % RF) followed by D. hansenii (22.8 % RF) and P. antarctica (16.8 % RF). The presence of the phylotypes related to species known for their potential applications as biocontrol agents and plant growth promoting hormone producers suggests that they may have valuable applications. In addition, our findings revealed the occurrence of novel phylotypes at high frequency, which should encourage extensive studies to discover novel yeast species and to understand their roles in the rice leaves. PMID:26122889

  10. Growth and manipulation of yeast.

    PubMed

    Treco, D A; Reynolds, A; Lundblad, V

    2001-05-01

    This unit describes preparation of selected media for growing yeast and also discusses strain storage and revival. Protocols are provided for the assay of beta-galactosidase in liquid culture and for transformation using lithium acetate. PMID:18429086

  11. Persistence of Two Non-Saccharomyces Yeasts (Hanseniaspora and Starmerella) in the Cellar

    PubMed Central

    Grangeteau, Cédric; Gerhards, Daniel; von Wallbrunn, Christian; Alexandre, Hervé; Rousseaux, Sandrine; Guilloux-Benatier, Michèle

    2016-01-01

    Different genera and/or species of yeasts present on grape berries, in musts and wines are widely described. Nevertheless, the community of non-Saccharomyces yeasts present in the cellar is still given little attention. Thus it is not known if the cellar is a real ecological niche for these yeasts or if it is merely a transient habitat for populations brought in by grape berries during the winemaking period. This study focused on three species of non-Saccharomyces yeasts commonly encountered during vinification: Starmerella bacillaris (synonymy with Candida zemplinina), Hanseniaspora guilliermondii and Hanseniaspora uvarum. More than 1200 isolates were identified at the strain level by FT-IR spectroscopy (207 different FTIR strain pattern). Only a small proportion of non-Saccharomyces yeasts present in musts came directly from grape berries for the three species studied. Some strains were found in the must in two consecutive years and some of them were also found in the cellar environment before the arrival of the harvest of second vintage. This study demonstrates for the first time the persistence of non-Saccharomyces yeast strains from year to year in the cellar. Sulfur dioxide can affect yeast populations in the must and therefore their persistence in the cellar environment. PMID:27014199

  12. Uranium bioprecipitation mediated by yeasts utilizing organic phosphorus substrates.

    PubMed

    Liang, Xinjin; Csetenyi, Laszlo; Gadd, Geoffrey Michael

    2016-06-01

    In this research, we have demonstrated the ability of several yeast species to mediate U(VI) biomineralization through uranium phosphate biomineral formation when utilizing an organic source of phosphorus (glycerol 2-phosphate disodium salt hydrate (C3H7Na2O6P·xH2O (G2P)) or phytic acid sodium salt hydrate (C6H18O24P6·xNa(+)·yH2O (PyA))) in the presence of soluble UO2(NO3)2. The formation of meta-ankoleite (K2(UO2)2(PO4)2·6(H2O)), chernikovite ((H3O)2(UO2)2(PO4)2·6(H2O)), bassetite (Fe(++)(UO2)2(PO4)2·8(H2O)), and uramphite ((NH4)(UO2)(PO4)·3(H2O)) on cell surfaces was confirmed by X-ray diffraction in yeasts grown in a defined liquid medium amended with uranium and an organic phosphorus source, as well as in yeasts pre-grown in organic phosphorus-containing media and then subsequently exposed to UO2(NO3)2. The resulting minerals depended on the yeast species as well as physico-chemical conditions. The results obtained in this study demonstrate that phosphatase-mediated uranium biomineralization can occur in yeasts supplied with an organic phosphate substrate as sole source of phosphorus. Further understanding of yeast interactions with uranium may be relevant to development of potential treatment methods for uranium waste and utilization of organic phosphate sources and for prediction of microbial impacts on the fate of uranium in the environment. PMID:26846744

  13. Analysis of the Secretomes of Paracoccidioides Mycelia and Yeast Cells

    PubMed Central

    Weber, Simone Schneider; Parente, Ana Flávia Alves; Borges, Clayton Luiz; Parente, Juliana Alves; Bailão, Alexandre Melo; de Almeida Soares, Célia Maria

    2012-01-01

    Paracoccidioides, a complex of several phylogenetic species, is the causative agent of paracoccidioidomycosis. The ability of pathogenic fungi to develop a multifaceted response to the wide variety of stressors found in the host environment is important for virulence and pathogenesis. Extracellular proteins represent key mediators of the host-parasite interaction. To analyze the expression profile of the proteins secreted by Paracoccidioides, Pb01 mycelia and yeast cells, we used a proteomics approach combining two-dimensional electrophoresis with matrix-assisted laser desorption ionization quadrupole time-of-flight mass spectrometry (MALDI-Q-TOF MS/MS). From three biological replicates, 356 and 388 spots were detected, in mycelium and yeast cell secretomes, respectively. In this study, 160 non-redundant proteins/isoforms were indentified, including 30 and 24 proteins preferentially secreted in mycelia and yeast cells, respectively. In silico analyses revealed that 65% of the identified proteins/isoforms were secreted primarily via non-conventional pathways. We also investigated the influence of protein export inhibition in the phagocytosis of Paracoccidioides by macrophages. The addition of Brefeldin A to the culture medium significantly decreased the production of secreted proteins by both Paracoccidioides and internalized yeast cells by macrophages. In contrast, the addition of concentrated culture supernatant to the co-cultivation significantly increased the number of internalized yeast cells by macrophages. Importantly, the proteins detected in the fungal secretome were also identified within macrophages. These results indicate that Paracoccidioides extracellular proteins are important for the fungal interaction with the host. PMID:23272246

  14. Divergence of iron metabolism in wild Malaysian yeast.

    PubMed

    Lee, Hana N; Mostovoy, Yulia; Hsu, Tiffany Y; Chang, Amanda H; Brem, Rachel B

    2013-12-01

    Comparative genomic studies have reported widespread variation in levels of gene expression within and between species. Using these data to infer organism-level trait divergence has proven to be a key challenge in the field. We have used a wild Malaysian population of S. cerevisiae as a test bed in the search to predict and validate trait differences based on observations of regulatory variation. Malaysian yeast, when cultured in standard medium, activated regulatory programs that protect cells from the toxic effects of high iron. Malaysian yeast also showed a hyperactive regulatory response during culture in the presence of excess iron and had a unique growth defect in conditions of high iron. Molecular validation experiments pinpointed the iron metabolism factors AFT1, CCC1, and YAP5 as contributors to these molecular and cellular phenotypes; in genome-scale sequence analyses, a suite of iron toxicity response genes showed evidence for rapid protein evolution in Malaysian yeast. Our findings support a model in which iron metabolism has diverged in Malaysian yeast as a consequence of a change in selective pressure, with Malaysian alleles shifting the dynamic range of iron response to low-iron concentrations and weakening resistance to extreme iron toxicity. By dissecting the iron scarcity specialist behavior of Malaysian yeast, our work highlights the power of expression divergence as a signpost for biologically and evolutionarily relevant variation at the organismal level. Interpreting the phenotypic relevance of gene expression variation is one of the primary challenges of modern genomics. PMID:24142925

  15. Assessing the potential of wild yeasts for bioethanol production.

    PubMed

    Ruyters, Stefan; Mukherjee, Vaskar; Verstrepen, Kevin J; Thevelein, Johan M; Willems, Kris A; Lievens, Bart

    2015-01-01

    Bioethanol fermentations expose yeasts to a new, complex and challenging fermentation medium with specific inhibitors and sugar mixtures depending on the type of carbon source. It is, therefore, suggested that the natural diversity of yeasts should be further exploited in order to find yeasts with good ethanol yield in stressed fermentation media. In this study, we screened more than 50 yeast isolates of which we selected five isolates with promising features. The species Candida bombi, Wickerhamomyces anomalus and Torulaspora delbrueckii showed better osmo- and hydroxymethylfurfural tolerance than Saccharomyces cerevisiae. However, S. cerevisiae isolates had the highest ethanol yield in fermentation experiments mimicking high gravity fermentations (25 % glucose) and artificial lignocellulose hydrolysates (with a myriad of inhibitors). Interestingly, among two tested S. cerevisiae strains, a wild strain isolated from an oak tree performed better than Ethanol Red, a S. cerevisiae strain which is currently commonly used in industrial bioethanol fermentations. Additionally, a W. anomalus strain isolated from sugar beet thick juice was found to have a comparable ethanol yield, but needed longer fermentation time. Other non-Saccharomyces yeasts yielded lower ethanol amounts. PMID:25413210

  16. Mitochondrial DNA size diversity in the Dekkera/Brettanomyces yeasts.

    PubMed

    McArthur, C R; Clark-Walker, G D

    1983-03-01

    Restriction endonuclease digestion of mitocondrial DNAs from the nine Dekkera/Brettanomyces yeasts have revealed that three separate pairs of species, namely D. bruxellensis/B. lambicus; B. abstinens/B. custersii and B. anomalus/B. clausenii have identical genomes. This observation suggests that such analysis of mtDNA could be an important procedure for yeast taxonomy. Sizes of mtDNAs showed a graded range from the 28 kbp molecule in B. custersianus to the 100 kbp molecule in B. custersii. Furthermore, although the mtDNAs from D. intermedia (72 kbp) and D. bruxellensis (82 kbp) differ in size by 10 kbp the restriction enzyme fragmentation patterns are generally similar. The differences are reminiscent of mtDNA polymorphisms found in strains of Saccharomyces cervisiae which result from insertions or deletions, chiefly within genic sequences. By analogy, the two Dekkera species may, on further analysis, be revealed as variants of a single species. PMID:24173115

  17. A new species of Leucothoid Amphipod, Anamixis bananarama, sp. n., from Shallow Coral Reefs in French Polynesia (Crustacea, Amphipoda, Leucothoidae)

    PubMed Central

    James Darwin, Thomas; Krapp-Schickel, Traudl

    2011-01-01

    Abstract Both leucomorph and anamorph developmental stages of Anamixis bananarama sp. n., are illustrated and described from shallow back reef environments of Moorea, French Polynesia. Distinguished by vestigial first gnathopods that persist in post-transformational adult males, this is the second species in the genus to exhibit this unusual character. In other features such as coxae and second gnathopods Anamixis bananarama sp. n. resembles other Pacific Plate endemics of Anamixis known from the region. Specific host association is not documented but suspected to be small calcareous asconoid sponges associated with coral rubble. PMID:21594109

  18. Attachment of the Yeast Rhodosporidium toruloides Is Mediated by Adhesives Localized at Sites of Bud Cell Development

    PubMed Central

    Buck, James W.; Andrews, John H.

    1999-01-01

    The basidiomycetous yeast Rhodosporidium toruloides (anamorph, Rhodotorula glutinis) is a common phylloplane epiphyte with biocontrol potential. To understand how R. toruloides adheres to plant surfaces, we obtained nonadherent fungal mutants after chemical mutagenesis with methane-sulfonic acid ethyl ester. Sixteen attachment-minus (Att−) mutants were identified by three methods: (i) screening capsule-minus colonies for loss of adhesive ability; (ii) enrichment for mutants unable to attach to polystyrene; and (iii) selection for reduced fluorescence of fluorescein isothiocyanate-concanavalin A (Con A)-stained cells by fluorescence-activated cell sorting. None of the 16 mutants attached to polystyrene or barley leaves. The lectin Con A eliminated adhesion in all of the wild-type isolates tested. Hapten competition assays indicated that Con A bound to mannose residues on the cell surface. Adhesion of wild-type R. toruloides was transient; nonadhesive cells subsequently became adhesive, with bud development. All Att− mutants and nonattaching wild-type cells lacked polar regions that stained intensely with fluorescein isothiocyanate-Con A and India ink. Lectin, enzyme, and chemical treatments showed that the polar regions consisted of alkali-soluble materials, including mannose residues. Tunicamycin treatment reduced wild-type adhesion, indicating that the mannose residues could be associated with glycoproteins. We concluded that compounds, including mannose residues, that are localized at sites of bud development mediate adhesion of R. toruloides to both polystyrene and barley leaf surfaces. PMID:9925569

  19. Riboneogenesis in yeast

    PubMed Central

    Clasquin, Michelle F.; Melamud, Eugene; Singer, Alexander; Gooding, Jessica R.; Xu, Xiaohui; Dong, Aiping; Cui, Hong; Campagna, Shawn R.; Savchenko, Alexei; Yakunin, Alexander F.; Rabinowitz, Joshua D.; Caudy, Amy A.

    2011-01-01

    Summary Gluconeogenesis converts three carbon units into glucose. Here we identify an analogous pathway in Saccharomyces cerevisiae for converting three carbon units into ribose, a component of nucleic acids and nucleotides. This riboneogenic pathway involves the enzyme sedoheptulose-1,7-bisphosphatase (SHB17), whose activity was identified based on accumulation of sedoheptulose-1,7-bisphosphate in the corresponding knockout strain. We determined the crystal structure of Shb17 in complex with sedoheptulose-1,7-bisphosphate, and found that the sugar is bound in the closed furan form in the active site. Like fructose-1,6-bisphosphate, sedoheptulose-1,7-bisphosphate is produced by aldolase, in this case from erythrose 4-phosphate and dihydroxyacetone phosphate. Hydrolysis of sedoheptulose-1,7-bisphosphate by SHB17 provides an energetically favorable input to the non-oxidative pentose phosphate pathway to drive ribose production. Flux through SHB17 is enhanced under conditions when ribose demand is high relative to demand for NADPH, including during ribosome biogenesis in metabolically synchronized yeast cells. Thus, riboneogenesis provides a thermodynamically-driven route of ribose production uncoupled from formation of NADPH. PMID:21663798

  20. Yeast Mitochondrial Transcriptomics

    PubMed Central

    Garcia, Mathilde; Darzacq, Xavier; Devaux, Frederic; Singer, Robert H.; Jacq, Claude

    2016-01-01

    Although 30 years ago it was strongly suggested that some cytoplasmic ribosomes are bound to the surface of yeast mitochondria, the mechanisms and the raison d’ětre of this process are not understood. For instance, it is not perfectly known which of the several hundred nuclearly encoded genes have to be translated to the mitochondrial vicinity to guide the import of the corresponding proteins. One can take advantage of several modern methods to address a number of aspects of the site-specific translation process of messenger ribonucleic acid (mRNA) coding for proteins imported into mitochondria. Three complementary approaches are presented to analyze the spatial distribution of mRNAs coding for proteins imported into mitochondria. Starting from biochemical purifications of mitochondria-bound polysomes, we describe a genomewide approach to classify all the cellular mRNAs according to their physical proximity with mitochondria; we also present real-time quantitative reverse transcription polymerase chain reaction monitoring of mRNA distribution to provide a quantified description of this localization. Finally, a fluorescence microscopy approach on a single living cell is described to visualize the in vivo localization of mRNAs involved in mitochondria biogenesis. PMID:18314748

  1. Synthetic Yeast Cooperation

    NASA Astrophysics Data System (ADS)

    Shou, Wenying; Burton, Justin

    2010-03-01

    Cooperation is wide-spread and has been postulated to drive major transitions in evolution. However, Darwinian selection favors ``cheaters'' that consume benefits without paying a fair cost. How did cooperation evolve against the threat of cheaters? To investigate the evolutionary trajectories of cooperation, we created a genetically tractable system that can be observed as it evolves from inception. The system consists of two engineered yeast strains -- a red-fluorescent strain that requires adenine and releases lysine and a yellow-fluorescent strain that requires lysine and releases adenine. Cells that consume but not supply metabolites would be cheaters. From the properties of two cooperating strains, we calculated and experimentally verified the minimal initial cell densities required for the viability of the cooperative system in the absence of exogenously added adenine and lysine. Strikingly, evolved cooperative systems were viable at 100-fold lower initial cell densities than their ancestors. We are investigating the nature and diversity of pro-cooperation changes, the dynamics of cooperator-cheater cocultures, and the effects of spatial environment on cooperation and cheating.

  2. Metabolic regulation of yeast

    NASA Astrophysics Data System (ADS)

    Fiechter, A.

    1982-12-01

    Metabolic regulation which is based on endogeneous and exogeneous process variables which may act constantly or time dependently on the living cell is discussed. The observed phenomena of the regulation are the result of physical, chemical, and biological parameters. These parameters are identified. Ethanol is accumulated as an intermediate product and the synthesis of biomass is reduced. This regulatory effect of glucose is used for the aerobic production of ethanol. Very high production rates are thereby obtained. Understanding of the regulation mechanism of the glucose effect has improved. In addition to catabolite repression, several other mechanisms of enzyme regulation have been described, that are mostly governed by exogeneous factors. Glucose also affects the control of respiration in a third class of yeasts which are unable to make use of ethanol as a substrate for growth. This is due to the lack of any anaplerotic activity. As a consequence, diauxic growth behavior is reduced to a one-stage growth with a drastically reduced cell yield. The pulse chemostat technique, a systematic approach for medium design is developed and medium supplements that are essential for metabolic control are identified.

  3. Studying Functions of All Yeast Genes Simultaneously

    NASA Technical Reports Server (NTRS)

    Stolc, Viktor; Eason, Robert G.; Poumand, Nader; Herman, Zelek S.; Davis, Ronald W.; Anthony Kevin; Jejelowo, Olufisayo

    2006-01-01

    A method of studying the functions of all the genes of a given species of microorganism simultaneously has been developed in experiments on Saccharomyces cerevisiae (commonly known as baker's or brewer's yeast). It is already known that many yeast genes perform functions similar to those of corresponding human genes; therefore, by facilitating understanding of yeast genes, the method may ultimately also contribute to the knowledge needed to treat some diseases in humans. Because of the complexity of the method and the highly specialized nature of the underlying knowledge, it is possible to give only a brief and sketchy summary here. The method involves the use of unique synthetic deoxyribonucleic acid (DNA) sequences that are denoted as DNA bar codes because of their utility as molecular labels. The method also involves the disruption of gene functions through deletion of genes. Saccharomyces cerevisiae is a particularly powerful experimental system in that multiple deletion strains easily can be pooled for parallel growth assays. Individual deletion strains recently have been created for 5,918 open reading frames, representing nearly all of the estimated 6,000 genetic loci of Saccharomyces cerevisiae. Tagging of each deletion strain with one or two unique 20-nucleotide sequences enables identification of genes affected by specific growth conditions, without prior knowledge of gene functions. Hybridization of bar-code DNA to oligonucleotide arrays can be used to measure the growth rate of each strain over several cell-division generations. The growth rate thus measured serves as an index of the fitness of the strain.

  4. Comparison of Three Statistical Methods for Establishing Tentative Wild-Type Population and Epidemiological Cutoff Values for Echinocandins, Amphotericin B, Flucytosine, and Six Candida Species as Determined by the Colorimetric Sensititre YeastOne Method

    PubMed Central

    Pemán, Javier; Hervás, David; Iñiguez, Carmen; Navarro, David; Echeverría, Julia; Martínez-Alarcón, José; Fontanals, Dionisia; Gomila-Sard, Bárbara; Buendía, Buenaventura; Torroba, Luis; Ayats, Josefina; Bratos, Angel; Sánchez-Reus, Ferran; Fernández-Natal, Isabel

    2012-01-01

    The Sensititre YeastOne (SYO) method is a widely used method to determine the susceptibility of Candida spp. to antifungal agents. CLSI clinical breakpoints (CBP) have been reported for antifungals, but not using this method. In the absence of CBP, epidemiological cutoff values (ECVs) are useful to separate wild-type (WT) isolates (those without mechanisms of resistance) from non-WT isolates (those that can harbor some resistance mechanisms), which is the goal of any susceptibility test. The ECVs for five agents, obtained using the MIC distributions determined by the SYO test, were calculated and contrasted with those for three statistical methods and the MIC50 and modal MIC, both plus 2-fold dilutions. The median ECVs (in mg/liter) (% of isolates inhibited by MICs equal to or less than the ECV; number of isolates tested) of the five methods for anidulafungin, micafungin, caspofungin, amphotericin B, and flucytosine, respectively, were as follows: 0.25 (98.5%; 656), 0.06 (95.1%; 659), 0.25 (98.7%; 747), 2 (100%; 923), and 1 (98.5%; 915) for Candida albicans; 8 (100%; 352), 4 (99.2%; 392), 2 (99.2%; 480), 1 (99.8%; 603), and 0.5 (97.9%; 635) for C. parapsilosis; 1 (99.2%; 123), 0.12 (99.2%; 121), 0.25 (99.2%; 138), 2 (100%; 171), and 0.5 (97.2%; 175) for C. tropicalis; 0.12 (96.6%; 174), 0.06 (96%; 176), 0.25 (98.4%; 188), 2 (100%; 209), and 0.25 (97.6%; 208) for C. glabrata; 0.25 (97%; 33), 0.5 (93.9%; 33), 1 (91.9%; 37), 4 (100%; 51), and 32 (100%; 53) for C. krusei; and 4 (100%; 33), 2 (100%; 33), 2 (100%; 54), 1 (100%; 90), and 0.25 (93.4%; 91) for C. orthopsilosis. The three statistical methods gave similar ECVs (within one dilution) and included ≥95% of isolates. These tentative ECVs would be useful for monitoring the emergence of isolates with reduced susceptibility by use of the SYO method. PMID:23015676

  5. Ecology of cultivable yeasts in pristine forests in northern Patagonia (Argentina) influenced by different environmental factors.

    PubMed

    Mestre, María Cecilia; Fontenla, Sonia; Rosa, Carlos A

    2014-06-01

    Environmental factors influencing the occurrence and community structure of soil yeasts in forests are not well studied. There are few studies dedicated to Southern Hemisphere soil yeasts populations and even fewer focused on temperate forests influenced by volcanic activity. The present work aimed to study the ecology of soil yeast communities from pristine forests influenced by different environmental factors (precipitation, physicochemical properties of soil, tree species, soil region, and season). The survey was performed in 4 northern Patagonian forests: 2 dominated by Nothofagus pumilio and 2 by Nothofagus antarctica. Yeast communities were described with ecological indices and species accumulation curves, and their association with environmental characteristics was assessed using multivariate analysis. Each forest site showed a particular arrangement of species as a result of environmental characteristics, such as dominant plant species, nutrient availability, and climatic characteristics. Cryptococcus podzolicus was most frequently isolated in nutrient-rich soils, Trichosporon porosum dominated cold mountain forests with low nutrient and water availability in soil, and capsulated yeasts such as Cryptococcus phenolicus dominated forest sites with low precipitation. The present work suggests that environmental factors affecting yeast communities may not be the current soil characteristics but the result of complex interactions of factors including natural disturbances like volcanic activity. PMID:24849380

  6. Taxonomic assessment and enzymes production by yeasts isolated from marine and terrestrial Antarctic samples.

    PubMed

    Duarte, A W F; Dayo-Owoyemi, I; Nobre, F S; Pagnocca, F C; Chaud, L C S; Pessoa, A; Felipe, M G A; Sette, L D

    2013-11-01

    The aim of the present study was to investigate the taxonomic identity of yeasts isolated from the Antarctic continent and to evaluate their ability to produce enzymes (lipase, protease and xylanase) at low and moderate temperatures. A total of 97 yeast strains were recovered from marine and terrestrial samples collected in the Antarctica. The highest amount of yeast strains was obtained from marine sediments, followed by lichens, ornithogenic soils, sea stars, Salpa sp., algae, sea urchin, sea squirt, stone with lichens, Nacella concinna, sea sponge, sea isopod and sea snail. Data from polyphasic taxonomy revealed the presence of 21 yeast species, distributed in the phylum Ascomycota (n = 8) and Basidiomycota (n = 13). Representatives of encapsulated yeasts, belonging to genera Rhodotorula and Cryptococcus were recovered from 7 different Antarctic samples. Moreover, Candida glaebosa, Cryptococcus victoriae, Meyerozyma (Pichia) guilliermondii, Rhodotorula mucilaginosa and R. laryngis were the most abundant yeast species recovered. This is the first report of the occurrence of some species of yeasts recovered from Antarctic marine invertebrates. Additionally, results from enzymes production at low/moderate temperatures revealed that the Antarctic environment contains metabolically diverse cultivable yeasts, which could be considered as a target for biotechnological applications. Among the evaluated yeasts in the present study 46.39, 37.11 and 14.43 % were able to produce lipase (at 15 °C), xylanase (at 15 °C) and protease (at 25 °C), respectively. The majority of lipolytic, proteolytic and xylanolytic strains were distributed in the phylum Basidiomycota and were mainly recovered from sea stars, lichens, sea urchin and marine sediments. PMID:24114281

  7. Yeasts found on an ephemeral reproductive caste of the leaf-cutting ant Atta sexdens rubropilosa.

    PubMed

    Arcuri, Silvio Lovato; Pagnocca, Fernando Carlos; Melo, Weilan Gomes da Paixão; Nagamoto, Nilson Satoru; Komura, Dirce Leimi; Rodrigues, Andre

    2014-09-01

    Winged males of leaf-cutting ants are considered an ephemeral reproductive caste only produced before the mating flight season. Although much is known about the yeast diversity found in fungus gardens of attine ants, no study has focused on the yeasts associated with males of leaf-cutting ants. Here, we surveyed the yeasts on the integuments of males of Atta sexdens rubropilosa and assessed their potential role in the attine ant-microbe symbiosis. Using culture-dependent techniques, we found yeasts to be abundant on the integuments of males (54.5 %, n = 200 alates). A total of 242 yeast strains were obtained representing six orders, ten genera and 25 species. Strains of Aureobasidium, Cryptococcus, Hannaella and Rhodotorula were prevalent on the integuments and likely originated from the fungus garden of the parental nest or from the soil. The majority of strains (87.1 %) produced at least one of the evaluated enzymes: pectinase, polygalacturonase, cellulase, xylanase, ligninases and lipase. Aureobasidium pullulans accounted for the highest number of strains that produced all enzymes. In addition, yeasts showed the ability to assimilate the resulting oligosaccharides, supporting observations of other studies that yeasts may be involved in the plant biomass metabolism in the fungus gardens. Because winged males harbor several yeasts with putative functional roles, these fungi may take part and be beneficial in the microbial consortia of the new incipient nest. PMID:25012689

  8. Study on the effects of near-future ocean acidification on marine yeasts: a microcosm approach

    NASA Astrophysics Data System (ADS)

    Krause, Evamaria; Wichels, Antje; Erler, René; Gerdts, Gunnar

    2013-12-01

    Marine yeasts play an important role in biodegradation and nutrient cycling and are often associated with marine flora and fauna. They show maximum growth at pH levels lower than present-day seawater pH. Thus, contrary to many other marine organisms, they may actually profit from ocean acidification. Hence, we conducted a microcosm study, incubating natural seawater from the North Sea at present-day pH (8.10) and two near-future pH levels (7.81 and 7.67). Yeasts were isolated from the initial seawater sample and after 2 and 4 weeks of incubation. Isolates were classified by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) and representative isolates were identified by partial sequencing of the large subunit rRNA gene. From the initial seawater sample, we predominantly isolated a yeast-like filamentous fungus related to Aureobasidium pullulans, Cryptococcus sp., Candida sake, and various cold-adapted yeasts. After incubation, we found more different yeast species at near-future pH levels than at present-day pH. Yeasts reacting to low pH were related to Leucosporidium scottii, Rhodotorula mucilaginosa, Cryptococcus sp., and Debaryomyces hansenii. Our results suggest that these yeasts will benefit from seawater pH reductions and give a first indication that the importance of yeasts will increase in a more acidic ocean.

  9. Dynamics and characterization of yeasts during natural fermentation of Italian sausages.

    PubMed

    Cocolin, Luca; Urso, Rosalinda; Rantsiou, Kalliopi; Cantoni, Carlo; Comi, Giuseppe

    2006-08-01

    A multiphasic approach was used to investigate the yeast ecology in Italian fermented sausages. Culture-dependent and -independent methods were applied to identify the yeast species during the maturation process and to characterize the numerically dominant species. Plating analysis and subsequent molecular identification of the isolates highlighted the dominance of Debaryomyces hansenii, but at least other three yeast species -Candida zeylanoides, Pichia triangularis and Metschnikowia pulcherrima - contributed to the fermentation as well. Direct denaturing gradient gel electrophoresis analysis confirmed that D. hansenii was the main yeast species present and its activity was also demonstrated. No other yeasts species were detected on the direct denaturing gradient gel electrophoresis gels, whereas DNA of Penicillium farinosum, Penicillium viridicatum and Mucor racemosus were present. Molecular characterization by RAPD-PCR analysis of the D. hansenii isolates demonstrated a shift in its population from the beginning to the end of the maturation of the sausages. Strains present during the early stages of the fermentation were grouped in clusters that differed from those isolated in the final phases of the maturation, underlining the genetic differences between these two populations of D. hansenii. However, all the isolates were able to grow in the presence of 3.5% sodium chloride and at 10 degrees C, evidence that these parameters did not select the species present at the end of the maturation period. PMID:16879421

  10. Anamorphic lens for tracking system

    NASA Technical Reports Server (NTRS)

    Burns, R. H.; Schmidt, L. F.

    1976-01-01

    Lens has 2:1 focal-length ratio, consists of three spherical and two cylindrical elements, and is 7.6 cm in length. When used in conjunction with image dissector tube, expected root-mean-square noise equivalent angle is approximately 8 arc seconds.

  11. The assessment of epiphytic yeast diversity in sugarcane phyllosphere in Thailand by culture-independent method.

    PubMed

    Nasanit, Rujikan; Tangwong-O-Thai, Apirat; Tantirungkij, Manee; Limtong, Savitree

    2015-12-01

    The diversity of epiphytic yeasts from sugarcane (Saccharum officinarum Linn.) phyllospheres in Thailand was investigated by culture-independent method based on the analysis of the D1/D2 domains of the large subunit rRNA gene sequences. Forty-five samples of sugarcane leaf were collected randomly from ten provinces in Thailand. A total of 1342 clones were obtained from 45 clone libraries. 426 clones (31.7 %) were closely related to yeast strains in the GenBank database, and they were clustered into 31 operational taxonomic units (OTUs) with a similarity threshold of 99 %. All OTU sequences were classified in phylum Basidiomycota which were closely related to 11 yeast species in seven genera including Cryptococcus flavus, Hannaella coprosmaensis, Rhodotorula taiwanensis, Jaminaea angkoreiensis, Malassezia restricta, Pseudozyma antarctica, Pseudozyma aphidis, Pseudozyma hubeiensis, Pseudozyma prolifica, Pseudozyma shanxiensis, and Sporobolomyces vermiculatus. The most predominant yeasts detected belonged to Ustilaginales with 89.4 % relative frequency and the prevalent yeast genus was Pseudozyma. However, the majority were unable to be identified as known yeast species and these sequences may represent the sequences of new yeast taxa. In addition, The OTU that closely related to P. prolifica was commonly detected in sugarcane phyllosphere. PMID:26615738

  12. Debaryomyces mycophilus sp. nov., a siderophore-dependent yeast isolated from woodlice.

    PubMed

    Thanh, Vu Nguyen; Van Dyk, Martha S; Wingfield, Michael J

    2002-08-01

    Four strains of an ascogenous yeast were isolated from the guts of the woodlice species Armadillidium vulgare (Latreille). This yeast differed from all known yeasts by its inability to grow in culture without the presence of a metabolite produced by some common soil fungi such as Cladosporium cladosporioides, Aspergillus alliaceus, and Penicillium spp. Phylogenetic analysis based on 18S rDNA and 26S rDNA (domain D1/D2) sequences indicated that the yeast represents a new taxon in the genus Debaryomyces. The new species Debaryomyces mycophilus is thus proposed. It was, furthermore, shown that the fungal metabolite necessary for growth of D. mycophilus did not provide the yeast with carbon, nitrogen or vitamins. The active compound was partially purified and it was shown that it is a siderophore used by the yeast as a source of iron. The addition of ferrichrome or high concentrations of FeCl(3) to growth media replaced the obligate dependence on a fungal metabolite. Symbiosis among fungi, based on the availability and utilization of iron, is an aspect of mycology that has not previously been recognized. The addition of chelated iron to isolation media could lead to the discovery of many unknown yeasts and fungi. PMID:12702293

  13. The Genetics of Non-conventional Wine Yeasts: Current Knowledge and Future Challenges

    PubMed Central

    Masneuf-Pomarede, Isabelle; Bely, Marina; Marullo, Philippe; Albertin, Warren

    2016-01-01

    Saccharomyces cerevisiae is by far the most widely used yeast in oenology. However, during the last decade, several other yeasts species has been purposed for winemaking as they could positively impact wine quality. Some of these non-conventional yeasts (Torulaspora delbrueckii, Metschnikowia pulcherrima, Pichia kluyveri, Lachancea thermotolerans, etc.) are now proposed as starters culture for winemakers in mixed fermentation with S. cerevisiae, and several others are the subject of various studies (Hanseniaspora uvarum, Starmerella bacillaris, etc.). Along with their biotechnological use, the knowledge of these non-conventional yeasts greatly increased these last 10 years. The aim of this review is to describe the last updates and the current state-of-art of the genetics of non-conventional yeasts (including S. uvarum, T. delbrueckii, S. bacillaris, etc.). We describe how genomics and genetics tools provide new data into the population structure and biodiversity of non-conventional yeasts in winemaking environments. Future challenges will lie on the development of selection programs and/or genetic improvement of these non-conventional species. We discuss how genetics, genomics and the advances in next-generation sequencing will help the wine industry to develop the biotechnological use of non-conventional yeasts to improve the quality and differentiation of wines. PMID:26793188

  14. Yeast Genetics and Biotechnological Applications

    NASA Astrophysics Data System (ADS)

    Mishra, Saroj; Baranwal, Richa

    Yeast can be recognized as one of the very important groups of microorganisms on account of its extensive use in the fermentation industry and as a basic eukaryotic model cellular system. The yeast Saccharomyces cerevisiae has been extensively used to elucidate the genetics and regulation of several key functions in the cell such as cell mating, electron transport chain, protein trafficking, cell cycle events and others. Even before the genome sequence of the yeast was out, the structural organization and function of several of its genes was known. With the availability of the origin of replication from the 2 μm plasmid and the development of transformation system, it became the host of choice for expression of a number of important proteins. A large number of episomal and integrative shuttle vectors are available for expression of mammalian proteins. The latest developments in genomics and micro-array technology have allowed investigations of individual gene function by site-specific deletion method. The application of metabolic profiling has also assisted in understanding the cellular network operating in this yeast. This chapter is aimed at reviewing the use of this system as an experimental tool for conducting classical genetics. Various vector systems available, foreign genes expressed and the limitations as a host will be discussed. Finally, the use of various yeast enzymes in biotechnology sector will be reviewed.

  15. FYPO: the fission yeast phenotype ontology

    PubMed Central

    Harris, Midori A.; Lock, Antonia; Bähler, Jürg; Oliver, Stephen G.; Wood, Valerie

    2013-01-01

    Motivation: To provide consistent computable descriptions of phenotype data, PomBase is developing a formal ontology of phenotypes observed in fission yeast. Results: The fission yeast phenotype ontology (FYPO) is a modular ontology that uses several existing ontologies from the open biological and biomedical ontologies (OBO) collection as building blocks, including the phenotypic quality ontology PATO, the Gene Ontology and Chemical Entities of Biological Interest. Modular ontology development facilitates partially automated effective organization of detailed phenotype descriptions with complex relationships to each other and to underlying biological phenomena. As a result, FYPO supports sophisticated querying, computational analysis and comparison between different experiments and even between species. Availability: FYPO releases are available from the Subversion repository at the PomBase SourceForge project page (https://sourceforge.net/p/pombase/code/HEAD/tree/phenotype_ontology/). The current version of FYPO is also available on the OBO Foundry Web site (http://obofoundry.org/). Contact: mah79@cam.ac.uk or vw253@cam.ac.uk PMID:23658422

  16. Yeast identification in floral nectar of Mimulus aurantiacus (Invited)

    NASA Astrophysics Data System (ADS)

    Kyauk, C.; Belisle, M.; Fukami, T.

    2009-12-01

    Nectar is such a sugar-rich resource that serves as a natural habitat in which microbes thrive. As a result, yeasts arrive to nectar on the bodies of pollinators such as hummingbirds and bees. Yeasts use the sugar in nectar for their own needs when introduced. This research focuses on the identification of different types of yeast that are found in the nectar of Mimulus aurantiacus (commonly known as sticky monkey-flower). Unopened Mimulus aurantiacus flower buds were tagged at Jasper Ridge and bagged three days later. Floral nectar was then extracted and plated on potato dextrose agar. Colonies on the plates were isolated and DNA was extracted from each sample using QIAGEN DNeasy Plant Mini Kit. The DNA was amplified through PCR and ran through gel electrophoresis. The PCR product was used to clone the nectar samples into an E.coli vector. Finally, a phylogenetic tree was created by BLAST searching sequences in GenBank using the Internal Transcribed Space (ITS) locus. It was found that 18 of the 50 identified species were Candida magnifica, 14 was Candida rancensis, 6 were Crytococcus albidus and there were 3 or less of the following: Starmella bombicola, Candida floricola, Aureobasidium pullulans, Pichia kluyvera, Metschnikowa cibodaserisis, Rhodotorua colostri, and Malassezia globosa. The low diversity of the yeast could have been due to several factors: time of collection, demographics of Jasper Ridge, low variety of pollinators, and sugar concentration of the nectar. The results of this study serve as a necessary first step for a recently started research project on ecological interactions between plants, pollinators, and nectar-living yeast. More generally, this research studies the use of the nectar-living yeast community as a natural microcosm for addressing basic questions about the role of dispersal and competitive and facilitative interactions in ecological succession.

  17. Isolation and Identification of Yeasts from Wild Flowers Collected around Jangseong Lake in Jeollanam-do, Republic of Korea, and Characterization of the Unrecorded Yeast Bullera coprosmaensis

    PubMed Central

    Han, Sang-Min; Hyun, Se-Hee; Lee, Hyang Burm; Lee, Hye Won; Kim, Ha-Kun

    2015-01-01

    Several types of yeasts were isolated from wild flowers around Jangseong Lake in Jeollanam-do, Republic of Korea and identified by comparing the nucleotide sequences of the PCR amplicons for the D1/D2 variable domain of the 26S ribosomal DNA using Basic Local Alignment Search Tool (BLAST) analysis. In total, 60 strains from 18 species were isolated, and Pseudozyma spp. (27 strains), which included Pseudozyma rugulosa (7 strains) and Pseudozyma aphidis (6 strains), was dominant species. Among the 60 strains, Bullera coprosmaensis JS00600 represented a newly recorded yeast strain in Korea, and its microbiological characteristics were investigated. The yeast cell has an oval-shaped morphology measuring 1.4 × 1.7 µm in size. Bullera coprosmaensis JS00600 is an asporous yeast that exhibits no pseudomycelium formation. It grew well in vitamin-free medium as well as in yeast extract-malt extract broth and yeast extract-peptone-dextrose (YPD) broth, and it is halotolerant growing in 10% NaCl-containing YPD broth. PMID:26539042

  18. Isolation and Identification of Yeasts from Wild Flowers Collected around Jangseong Lake in Jeollanam-do, Republic of Korea, and Characterization of the Unrecorded Yeast Bullera coprosmaensis.

    PubMed

    Han, Sang-Min; Hyun, Se-Hee; Lee, Hyang Burm; Lee, Hye Won; Kim, Ha-Kun; Lee, Jong-Soo

    2015-09-01

    Several types of yeasts were isolated from wild flowers around Jangseong Lake in Jeollanam-do, Republic of Korea and identified by comparing the nucleotide sequences of the PCR amplicons for the D1/D2 variable domain of the 26S ribosomal DNA using Basic Local Alignment Search Tool (BLAST) analysis. In total, 60 strains from 18 species were isolated, and Pseudozyma spp. (27 strains), which included Pseudozyma rugulosa (7 strains) and Pseudozyma aphidis (6 strains), was dominant species. Among the 60 strains, Bullera coprosmaensis JS00600 represented a newly recorded yeast strain in Korea, and its microbiological characteristics were investigated. The yeast cell has an oval-shaped morphology measuring 1.4 × 1.7 µm in size. Bullera coprosmaensis JS00600 is an asporous yeast that exhibits no pseudomycelium formation. It grew well in vitamin-free medium as well as in yeast extract-malt extract broth and yeast extract-peptone-dextrose (YPD) broth, and it is halotolerant growing in 10% NaCl-containing YPD broth. PMID:26539042

  19. Simultaneous saccharification and fermentation (SSF) using cellobiose fermenting yeast Brettanomyces custersii

    SciTech Connect

    Spindler, Diane D.; Grohmann, Karel; Wyman, Charles E.

    1992-01-01

    A process for producing ethanol from plant biomass includes forming a substrate from the biomass with the substrate including hydrolysates of cellulose and hemicellulose. A species of the yeast Brettanomyces custersii (CBS 5512), which has the ability to ferment both cellobiose and glucose to ethanol, is then selected and isolated. The substrate is inoculated with this yeast, and the inoculated substrate is then fermented under conditions favorable for cell viability and conversion of hydrolysates to ethanol.

  20. Draft Genome Sequence of Salt-Tolerant Yeast Debaryomyces hansenii var. hansenii MTCC 234

    PubMed Central

    Kumar, Shailesh; Randhawa, Anmoldeep; Ganesan, Kaliannan

    2012-01-01

    Debaryomyces hansenii is one of the most halotolerant species of yeast, and the genome sequence of D. hansenii strain CBS767 is already available. Here we report the 11.46-Mb draft genome of D. hansenii strain MTCC 234, which is even more halotolerant than strain CBS767. Comparative analysis of these sequences would definitely provide further insight into the halotolerance of this yeast. PMID:22744717

  1. Simultaneous saccharification and fermentation (SSF) using cellobiose fermenting yeast Brettanomyces custersii

    DOEpatents

    Spindler, D.D.; Grohmann, K.; Wyman, C.E.

    1992-03-31

    A process for producing ethanol from plant biomass includes forming a substrate from the biomass with the substrate including hydrolysates of cellulose and hemicellulose. A species of the yeast Brettanomyces custersii (CBS 5512), which has the ability to ferment both cellobiose and glucose to ethanol, is then selected and isolated. The substrate is inoculated with this yeast, and the inoculated substrate is then fermented under conditions favorable for cell viability and conversion of hydrolysates to ethanol. 2 figs.

  2. Application of temperature gradient gel electrophoresis to the study of yeast diversity in the estuary of the Tagus river, Portugal.

    PubMed

    Gadanho, Mário; Sampaio, José Paulo

    2004-12-01

    Temperature gradient gel electrophoresis (TGGE) was employed for the assessment of yeast diversity in the estuary of the Tagus river (Portugal). The molecular detection of yeasts was carried out directly from water samples and, in parallel, a cultivation approach by means of an enrichment step was employed. A nested PCR was employed to obtain a fungal amplicon containing the D2 domain of the 26S rRNA gene. For identification the TGGE bands were extracted, re-amplified, and sequenced. Fourteen fungal taxa were detected and all except one were yeasts. Most yeast sequences corresponded to members of the Ascomycota and only three belonged to the Basidiomycota. Five yeasts (four ascomycetes and one basidiomycete) could not be identified to the species level due to the uniqueness of their sequences. The number of species detected after enrichment was higher than the number of taxa found using the direct detection method. This suggests that some yeast populations are present in densities that are below the detection threshold of the method. With respect to the analysis of the yeast community structure, our results indicate that the dominant populations belong to Debaryomyces hansenii, Rhodotorula mucilaginosa, Cryptococcus longus, and to an uncultured basidiomycetous yeast phylogenetically close to Cr. longus. The combined analysis of direct detection and cultivation approaches indicates a similar community structure at the two sampled sites since nine species were present at both localities. PMID:15556087

  3. The mitochondrial permeability transition from yeast to mammals

    PubMed Central

    Azzolin, Luca; von Stockum, Sophia; Basso, Emy; Petronilli, Valeria; Forte, Michael A.; Bernardi, Paolo

    2010-01-01

    Regulated permeability changes have been detected in mitochondria across species. We review here their key features, with the goal of assessing whether a “permeability transition” similar to that observed in higher eukaryotes is present in other species. The recent discoveries (i) that treatment with cyclosporin A unmasks an inhibitory site for Pi [Basso et al. (2008) J. Biol Chem. 283, 26307–26311], the classical inhibitor of the permeability transition of yeast; and (ii) that under proper experimental conditions a matrix Ca2+-dependence can be demonstrated in yeast as well [Yamada et al. (2009) Biochim. Biophys. Acta 1787, 1486–1491] suggest that the mitochondrial permeability transition has been conserved during evolution. PMID:20398660

  4. Genomic evolution of the ascomycetous yeasts

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Yeasts are important for industrial and biotechnological processes and show remarkable metabolic and phylogenetic diversity despite morphological similarities. We have sequenced the genomes of 16 ascomycete yeasts of taxonomic and industrial importance including members of Saccharomycotina and Taphr...

  5. Yeast Can Affect Behavior and Learning.

    ERIC Educational Resources Information Center

    Crook, William G.

    1984-01-01

    A pediatrician recounts his experiences in diagnosing and treating allergies to common yeast germs that may result in behavior and learning problems. He lists characteristics that may predispose children to yeast-connected health problems. (CL)

  6. Pseudohyphal variations of yeasts exposed to specific space flight parameters.

    PubMed

    Volz, P A; Hunter, R L

    1998-01-01

    Phenotypes of Saccharomyces cerevisiae and Rhodotorula rubra exposed to specific parameters of space flight, which were measured both quantitatively and qualitatively, produced variations in pseudohyphal formation. Both the length of the parent and branch psuedohyphal filaments varied according to specific wavelengths and energy levels of UV light exposures when phenotypic isolates were compared with the parent or ground control isolate of each yeast species. PMID:9881461

  7. The Vineyard Yeast Microbiome, a Mixed Model Microbial Map

    PubMed Central

    Setati, Mathabatha Evodia; Jacobson, Daniel; Andong, Ursula-Claire; Bauer, Florian

    2012-01-01

    Vineyards harbour a wide variety of microorganisms that play a pivotal role in pre- and post-harvest grape quality and will contribute significantly to the final aromatic properties of wine. The aim of the current study was to investigate the spatial distribution of microbial communities within and between individual vineyard management units. For the first time in such a study, we applied the Theory of Sampling (TOS) to sample gapes from adjacent and well established commercial vineyards within the same terroir unit and from several sampling points within each individual vineyard. Cultivation-based and molecular data sets were generated to capture the spatial heterogeneity in microbial populations within and between vineyards and analysed with novel mixed-model networks, which combine sample correlations and microbial community distribution probabilities. The data demonstrate that farming systems have a significant impact on fungal diversity but more importantly that there is significant species heterogeneity between samples in the same vineyard. Cultivation-based methods confirmed that while the same oxidative yeast species dominated in all vineyards, the least treated vineyard displayed significantly higher species richness, including many yeasts with biocontrol potential. The cultivatable yeast population was not fully representative of the more complex populations seen with molecular methods, and only the molecular data allowed discrimination amongst farming practices with multivariate and network analysis methods. Importantly, yeast species distribution is subject to significant intra-vineyard spatial fluctuations and the frequently reported heterogeneity of tank samples of grapes harvested from single vineyards at the same stage of ripeness might therefore, at least in part, be due to the differing microbiota in different sections of the vineyard. PMID:23300721

  8. Exploring the yeast biodiversity of green table olive industrial fermentations for technological applications.

    PubMed

    Bautista-Gallego, J; Rodríguez-Gómez, F; Barrio, E; Querol, A; Garrido-Fernández, A; Arroyo-López, F N

    2011-05-27

    In recent years, there has been an increasing interest in identifying and characterizing the yeast populations associated with diverse types of table olive elaborations because of the many desirable technological properties of these microorganisms. In this work, a total of 199 yeast isolates were directly obtained from industrial green table olive fermentations and genetically identified by means of a RFLP analysis of the 5.8S-ITS region and sequencing of the D1/D2 domains of the 26S rDNA gene. Candida diddensiae, Saccharomyces cerevisiae and Pichia membranifaciens were the most abundant yeast species isolated from directly brined Aloreña olives, while for Gordal and Manzanilla cultivars they were Candida tropicalis, Pichia galeiformis and Wickerhamomyces anomalus. In the case of Gordal and Manzanilla green olives processed according to the Spanish style, the predominant yeasts were Debaryomyces etchellsii, C. tropicalis, P. galeiformis and Kluyveromyces lactis. Biochemical activities of technological interest were then qualitatively determined for isolates belonging to all yeast species. This preliminary screening identified two isolates of W. anomalus with interesting properties, such as a strong β-glucosidase and esterase activity, and a moderate catalase and lipolytic activity, which were also confirmed by quantitative assays. The results obtained in this survey show the potential use that some yeast species could have as starters, alone or in combination with lactic acid bacteria, during olive processing. PMID:21497408

  9. Two-dimensional gel analysis of the proteome of lager brewing yeasts.

    PubMed

    Joubert, R; Brignon, P; Lehmann, C; Monribot, C; Gendre, F; Boucherie, H

    2000-04-01

    Modern lager brewing yeasts used in beer production are hybrid strains consisting of at least two different genomes. To obtain information on the identity of the parental strains that gave rise to industrial lager yeasts, we used two-dimensional (2-D) gel electrophoresis and analysed the proteomes of different Saccharomyces species isolated from breweries. We found that the proteome of lager brewing yeasts and of the type strains of S. carlsbergensis, S. monacensis and S. pastorianus can be interpreted as the superimposition of two elementary patterns. One originates from proteins encoded by a S. cerevisiae-like genome. The other corresponds to a divergent Saccharomyces species whose best representative is a particular S. pastorianus strain, NRRL Y-1551. A map of industrial lager brewing yeasts has been established, with the individual origin of proteins and with identification of protein spots by comparison to known S. cerevisiae proteins. This 2-D map can be accessed on the Lager Brewing Yeast Protein Map server through the World Wide Web. This study provides the first example of the use of proteome analysis for investigating taxonomic relationships between divergent yeast species. PMID:10790688

  10. Combinatorial Regulation in Yeast Transcription Networks

    NASA Astrophysics Data System (ADS)

    Li, Hao

    2006-03-01

    Yeast has evolved a complex network to regulate its transcriptional program in response to changes in environment. It is quite common that in response to an external stimulus, several transcription factors will be activated and they work in combinations to control different subsets of genes in the genome. We are interested in how the promoters of genes are designed to integrate signals from multiple transcription factors and what are the functional and evolutionary constraints. To answer how, we have developed a number of computational algorithms to systematically map the binding sites and target genes of transcription factors using sequence and gene expression data. To analyze the functional constraints, we have employed mechanistic models to study the dynamic behavior of genes regulated by multiple factors. We have also developed methods to trace the evolution of transcriptional networks via comparative analysis of multiple species.

  11. Control of maltase synthesis in yeast.

    PubMed

    Needleman, R

    1991-09-01

    Maltose fermentation in Saccharomyces species requires the presence of at least one of five unlinked MAL loci: MAL1, MAL2, MAL3, MAL4 and MAL6. Each MAL locus is complex consisting of at least three genes: a trans-acting activator, a maltose permease, and maltase. All the MAL loci show homology to each other both at the sequence level as determined by Southern transfer analysis and at the functional level as determined by complementation. We describe the organization of the MAL loci in yeast and the basic features of their regulation. The analysis of MAL has contributed to our understanding of the evolution of multigenic families, the global integration of carbohydrate metabolism, and gene regulation. PMID:1766381

  12. Diversity and extracellular enzymatic activities of yeasts isolated from King George Island, the sub-Antarctic region

    PubMed Central

    2012-01-01

    Background Antarctica has been successfully colonized by microorganisms despite presenting adverse conditions for life such as low temperatures, high solar radiation, low nutrient availability and dryness. Although these “cold-loving” microorganisms are recognized as primarily responsible for nutrient and organic matter recycling/mineralization, the yeasts, in particular, remain poorly characterized and understood. The aim of this work was to study the yeast microbiota in soil and water samples collected on King George Island. Results A high number of yeast isolates was obtained from 34 soil and 14 water samples. Molecular analyses based on rDNA sequences revealed 22 yeast species belonging to 12 genera, with Mrakia and Cryptococcus genera containing the highest species diversity. The species Sporidiobolus salmonicolor was by far the most ubiquitous, being identified in 24 isolates from 13 different samples. Most of the yeasts were psychrotolerant and ranged widely in their ability to assimilate carbon sources (consuming from 1 to 27 of the 29 carbon sources tested). All species displayed at least 1 of the 8 extracellular enzyme activities tested. Lipase, amylase and esterase activity dominated, while chitinase and xylanase were less common. Two yeasts identified as Leuconeurospora sp. and Dioszegia fristingensis displayed 6 enzyme activities. Conclusions A high diversity of yeasts was isolated in this work including undescribed species and species not previously isolated from the Antarctic region, including Wickerhamomyces anomalus, which has not been isolated from cold regions in general. The diversity of extracellular enzyme activities, and hence the variety of compounds that the yeasts may degrade or transform, suggests an important nutrient recycling role of microorganisms in this region. These yeasts are of potential use in industrial applications requiring high enzyme activities at low temperatures. PMID:23131126

  13. The environmental and intrinsic yeast diversity of Cuban cocoa bean heap fermentations.

    PubMed

    Fernández Maura, Yurelkys; Balzarini, Tom; Clapé Borges, Pablo; Evrard, Pierre; De Vuyst, Luc; Daniel, H-M

    2016-09-16

    The environmental yeast diversity of spontaneous cocoa bean fermentations in east Cuba was investigated. Seven fermentations, 25 equipment- and handling-related samples, and 115 environmental samples, such as flowers, leaf and cocoa pod surfaces, as well as drosophilid insects, were analysed. The basic fermentation parameters temperature and pH were recorded during five fermentations for at least six days. A total of 435 yeast isolates were identified by a combination of PCR-fingerprinting of genomic DNA with the M13 primer and sequence analysis of DNA from representative isolates, using the internal transcribed spacer region, the D1/D2 region of the large subunit rRNA gene, and an actin gene-encoding fragment, as required. Among 65 yeast species detected, Pichia manshurica and Hanseniaspora opuntiae were the most frequently isolated species, obtained from five and four fermentations, followed in frequency by Pichia kudriavzevii from two fermentations. Saccharomyces cerevisiae was isolated only occasionally. Cocoa fermentation yeast species were also present on processing equipment. The repeated isolation of a preliminarily as Yamadazyma sp. classified species, a group of strains similar to Saccharomycopsis crataegensis from fermentations and equipment, and the isolation of fifteen other potentially novel yeast species in low numbers provides material for further studies. Environmental samples showed higher yeast diversity compared to the fermentations, included the most frequent fermentation species, whereas the most frequently isolated environmental species were Candida carpophila, Candida conglobata, and Candida quercitrusa. Potential selective advantages of the most frequently isolated species were only partly explained by the physiological traits tested. For instance, tolerance to higher ethanol concentrations was more frequent in strains of Pichia spp. and S. cerevisiae compared to Hanseniaspora spp.; the ability to also assimilate ethanol might have

  14. Diversity and molecular determination of wild yeasts in a central Washington vineyard

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Yeasts were isolated from grapes collected from a research vineyard at the WSU IAREC, located at Prosser, WA. Species determination was based on cultural features, microscopic morphology, physiological tests and analysis of ITS and D1/D2 rDNA sequence data. 53 species were found distributed among fi...

  15. Yeast: A Research Organism for Teaching Genetics.

    ERIC Educational Resources Information Center

    Manney, Thomas R.; Manney, Monta L.

    1992-01-01

    Explains why laboratory strains of bakers yeast, Saccharomyces cerevisiae, are particularly suited for classroom science activities. Describes the sexual life cycle of yeast and the genetic system with visible mutations. Presents an overview of activities that can be done with yeast and gives a source for teachers to obtain more information. (PR)

  16. 21 CFR 73.355 - Phaffia yeast.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 1 2011-04-01 2011-04-01 false Phaffia yeast. 73.355 Section 73.355 Food and... ADDITIVES EXEMPT FROM CERTIFICATION Foods § 73.355 Phaffia yeast. (a) Identity. (1) The color additive phaffia yeast consists of the killed, dried cells of a nonpathogenic and nontoxicogenic strain of...

  17. 21 CFR 73.355 - Phaffia yeast.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 1 2014-04-01 2014-04-01 false Phaffia yeast. 73.355 Section 73.355 Food and... ADDITIVES EXEMPT FROM CERTIFICATION Foods § 73.355 Phaffia yeast. (a) Identity. (1) The color additive phaffia yeast consists of the killed, dried cells of a nonpathogenic and nontoxicogenic strain of...

  18. 21 CFR 73.355 - Phaffia yeast.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 1 2010-04-01 2010-04-01 false Phaffia yeast. 73.355 Section 73.355 Food and... ADDITIVES EXEMPT FROM CERTIFICATION Foods § 73.355 Phaffia yeast. (a) Identity. (1) The color additive phaffia yeast consists of the killed, dried cells of a nonpathogenic and nontoxicogenic strain of...

  19. 21 CFR 73.355 - Phaffia yeast.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 1 2012-04-01 2012-04-01 false Phaffia yeast. 73.355 Section 73.355 Food and... ADDITIVES EXEMPT FROM CERTIFICATION Foods § 73.355 Phaffia yeast. (a) Identity. (1) The color additive phaffia yeast consists of the killed, dried cells of a nonpathogenic and nontoxicogenic strain of...

  20. 21 CFR 73.355 - Phaffia yeast.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 1 2013-04-01 2013-04-01 false Phaffia yeast. 73.355 Section 73.355 Food and... ADDITIVES EXEMPT FROM CERTIFICATION Foods § 73.355 Phaffia yeast. (a) Identity. (1) The color additive phaffia yeast consists of the killed, dried cells of a nonpathogenic and nontoxicogenic strain of...