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1.
Article in English | MEDLINE | ID: mdl-38407127

ABSTRACT

Four yeast isolates collected from flowers from different ecosystems in Brazil, one from fruit of Nothofagus alpina in Argentina, three from flowers of Neltuma chilensis in Chile and one obtained from the proventriculus of a female bumblebee in Canada were demonstred, by analysis of the sequences of the internal transcribed spacer (ITS) region and D1/D2 domains of the large subunit rRNA gene, to represent two novel species of the genus Starmerella. These species are described here as Starmerella gilliamiae f.a, sp. nov. (CBS 16166T; Mycobank MB 851206) and Starmerella monicapupoae f.a., sp. nov. (PYCC 8997T; Mycobank MB 851207). The results of a phylogenomic analysis using 1037 single-copy orthogroups indicated that S. gilliamiae is a member of a subclade that contains Starmerella opuntiae, Starmerella aceti and Starmerella apicola. The results also indicated that S. monicapupoae is phylogenetically related to Starmerella riodocensis. The two isolates of S. monicapupoae were obtained from flowers in Brazil and were probably vectored by insects that visit these substrates. Starmerella gilliamiae has a wide geographical distribution having been isolated in flowers from Brazil and Chile, fruit from Argentina and a bumblebee from Canada.


Subject(s)
Ecosystem , Saccharomycetales , Animals , Phylogeny , Sequence Analysis, DNA , RNA, Ribosomal, 16S/genetics , DNA, Bacterial/genetics , Bacterial Typing Techniques , Base Composition , Fatty Acids/chemistry , Saccharomycetales/genetics , Insecta
2.
Int J Syst Evol Microbiol ; 71(11)2021 Nov.
Article in English | MEDLINE | ID: mdl-34726589

ABSTRACT

During studies of yeasts associated with soil in a Cerrado-Atlantic Rain Forest ecotone site in Brazil, three orange-pigmented yeast strains were isolated from samples collected in Minas Gerais state, Brazil. Molecular analyses combining the 26S rRNA gene (D1/D2 domains) and the internal transcribed spacer (ITS) sequences as well as whole-genome sequence data showed that these strains could not be ascribed to any known species in the basidiomycetous genus Phaffia, and thus they are considered to represent a novel species for which the name Phaffia brasiliana sp. nov. is proposed. The holotype is CBS 16121T and the MycoBank number is MB 839315. The occurrence of P. brasiliana in a tropical region is unique for the genus, since all other species occur in temperate regions. Two factors appear to contribute to the distribution of the novel taxon: first, the region where it was found has relatively moderate temperature ranges and, second, an adaptation to grow or withstand temperatures higher than those of the other species in the genus seems to be in place.


Subject(s)
Basidiomycota/classification , Phylogeny , Rainforest , Soil Microbiology , Basidiomycota/isolation & purification , Brazil , DNA, Fungal/genetics , DNA, Ribosomal Spacer/genetics , Mycological Typing Techniques , RNA, Ribosomal, 16S/genetics , Sequence Analysis, DNA
3.
Microbiology (Reading) ; 164(9): 1069-1071, 2018 09.
Article in English | MEDLINE | ID: mdl-30175956

ABSTRACT

Saccharomyces eubayanus was described less than 10 years ago and its discovery settled the long-lasting debate on the origins of the cold-tolerant yeast responsible for lager beer fermentation. The largest share of the genetic diversity of S. eubayanus is located in South America, and strains of this species have not yet been found in Europe. One or more hybridization events between S. eubayanus and S. cerevisiae ale beer strains gave rise to S. pastorianus, the allopolyploid yeasts responsible for lager beer production worldwide. The identification of the missing progenitor of lager yeast opened new avenues for brewing yeast research. It allowed not only the selective breeding of new lager strains, but revealed also a wild yeast with interesting brewing abilities so that a beer solely fermented by S. eubayanus is currently on the market.


Subject(s)
Beer/microbiology , Genetic Variation , Saccharomyces/genetics , Saccharomyces/metabolism , Crosses, Genetic , Fermentation , South America
4.
Int J Syst Evol Microbiol ; 68(6): 1937-1941, 2018 Jun.
Article in English | MEDLINE | ID: mdl-29676729

ABSTRACT

During a survey of the yeast community associated with the phylloplane of corn in Thailand, a basidiomycetous yeast strain belonging to the genus Papiliotrema was isolated. Analyses of the D1/D2 domains of the 26S (LSU) rRNA gene and complete ITS region supported the recognition of a novel species, for which the name Papiliotrema plantarum sp. nov. is proposed (type strain DMKU-CP801T=CBS 15220T=PYCC 7257T). Another strain of P. plantarum sp. nov., isolated in French Guiana, was found to be sexually compatible with the Thai isolate and mycelium with clamp connections, basidia and basidiospores were observed in culture. The basidial morphology of P. plantarum combined features previously observed for Papiliotrema bandonii and Papiliotrema fuscus, which represent the only sexual species hitherto known in the genus, i.e. transversely septate basidia, with sexual structures of the Tremella type.


Subject(s)
Basidiomycota/classification , Phylogeny , Plant Leaves/microbiology , Zea mays/microbiology , Basidiomycota/genetics , Basidiomycota/isolation & purification , DNA, Fungal/genetics , DNA, Ribosomal Spacer/genetics , French Guiana , Mycological Typing Techniques , RNA, Ribosomal/genetics , Sequence Analysis, DNA , Spores, Fungal
5.
Int J Syst Evol Microbiol ; 66(9): 3600-3606, 2016 Sep.
Article in English | MEDLINE | ID: mdl-27306608

ABSTRACT

Two yeast strains that are members of the same species were isolated from different marine habitats, i.e. one from Mid-Atlantic Ridge ocean water samples located in the direct vicinity of black smokers near the Rainbow deep-sea hydrothermal vent and one from Brazilian marine water samples off the Ipanema beach. Strains CLIB 1964T and CLIB 1965 are anamorphic ascomycetous yeasts affiliated to the Yamadazyma clade of Saccharomycetales. Interestingly, these strains were phylogenetically and distinctly positioned into a group of species comprising all species of the genus Yamadazyma isolated from marine habitats including deep-sea hydrothermal vents, i.e.Candida atmosphaerica,C. spencermartinsiae,C. atlantica,C. oceani and C. taylorii. These strains differed significantly in their D1/D2 domain sequences of the LSU rRNA gene from the closely related species mentioned above, by 2.6, 3.0, 3.4, 3.8 and 6.0 %, respectively. Internal transcribed spacer region sequence divergence was also significant and corresponded to 4.6, 4.7, 4.7, 12.0 and 24.7 % with C. atlantica,C. atmosphaerica, C. spencermartinsiae,C. oceani and C. taylorii, respectively. Phenotypically, strains CLIB 1964T and CLIB 1965 could be distinguished from closely related species by their inability to assimilate l-sorbose. CLIB 1964T (=CBS 14301T=UBOCC-A-214001T) is the designated type strain for Yamadazyma barbieri sp. nov. The MycoBank number is MB 815884.


Subject(s)
Hydrothermal Vents/microbiology , Phylogeny , Saccharomycetales/classification , Atlantic Ocean , Brazil , DNA, Fungal/genetics , Mycological Typing Techniques , RNA, Ribosomal/genetics , Saccharomycetales/genetics , Saccharomycetales/isolation & purification , Sequence Analysis, DNA
6.
Genome Biol Evol ; 8(2): 317-29, 2016 Jan 18.
Article in English | MEDLINE | ID: mdl-26782936

ABSTRACT

The natural biology of Saccharomyces cerevisiae, the best known unicellular model eukaryote, remains poorly documented and understood although recent progress has started to change this situation. Studies carried out recently in the Northern Hemisphere revealed the existence of wild populations associated with oak trees in North America, Asia, and in the Mediterranean region. However, in spite of these advances, the global distribution of natural populations of S. cerevisiae, especially in regions were oaks and other members of the Fagaceae are absent, is not well understood. Here we investigate the occurrence of S. cerevisiae in Brazil, a tropical region where oaks and other Fagaceae are absent. We report a candidate natural habitat of S. cerevisiae in South America and, using whole-genome data, we uncover new lineages that appear to have as closest relatives the wild populations found in North America and Japan. A population structure analysis revealed the penetration of the wine genotype into the wild Brazilian population, a first observation of the impact of domesticated microbe lineages on the genetic structure of wild populations. Unexpectedly, the Brazilian population shows conspicuous evidence of hybridization with an American population of Saccharomyces paradoxus. Introgressions from S. paradoxus were significantly enriched in genes encoding secondary active transmembrane transporters. We hypothesize that hybridization in tropical wild lineages may have facilitated the habitat transition accompanying the colonization of the tropical ecosystem.


Subject(s)
Ecosystem , Hybridization, Genetic , Saccharomyces cerevisiae/genetics , Brazil , Fagaceae/microbiology , Genetic Speciation , Genome, Fungal , Membrane Transport Proteins/genetics , Saccharomyces cerevisiae/isolation & purification , Saccharomyces cerevisiae Proteins/genetics
7.
Int J Syst Evol Microbiol ; 65(12): 4474-4478, 2015 Dec.
Article in English | MEDLINE | ID: mdl-26364192

ABSTRACT

Two strains of a novel cactophilic yeast species were isolated from the columnar cactus Pilosocereus arrabidae in a sand dune ecosystem in Rio de Janeiro, Brazil. Phylogenetic analysis of sequences of the large subunit rRNA gene D1/D2 domains showed that the strains represent a sister species to Starmera caribaea, from which it differs by 21 nt substitutions and two indels. The novel species is heterothallic and the asci are deliquescent with the formation of two to four hat-shaped ascospores. The name Starmera pilosocereana sp. nov. is proposed for the species. The type strain is UFMG-CM-Y316T ( = CBS 13266T) and the allotype is UFMG-CM-Y346a ( = CBS 13265). The Mycobank number is MB 810683. In addition, Candida stellimalicola belonging to the Starmera clade, is reassigned to Starmera as a new combination.


Subject(s)
Cactaceae/microbiology , Phylogeny , Saccharomycetales/classification , Brazil , DNA, Fungal/genetics , Ecosystem , Molecular Sequence Data , Mycological Typing Techniques , RNA, Ribosomal/genetics , Saccharomycetales/genetics , Saccharomycetales/isolation & purification , Sequence Analysis, DNA
8.
FEMS Yeast Res ; 15(4): fov019, 2015 Jun.
Article in English | MEDLINE | ID: mdl-25903381

ABSTRACT

Species of Leucosporidiales are a group of psychrotolerant yeasts with biotechnological potential. In the present work, we studied the phenotypic, genetic and sexual characteristics of three species of this genus (Leucosporidium scottii, Leucosporidiella creatinivora and Le. yakutica) to clarify the evolutionary relationship among these closely related taxa. From the results obtained, it becomes clear that these yeasts can interbreed. Although genetic delimitation is possible for the three species, the extent of nucleotide substitutions and phenotypic differences observed between them are lower than that expected for species that have ended the speciation process. Our taxonomic conclusion is to maintain the three taxa until further genomic data are gathered. However, the concept of L. scottii species complex is proposed for this group of species. Finally, we transfer all Leucosporidiella and Mastigobasidium species to Leucosporidium (Leucosporidiales), and, in order to end the polyphyly condition of these taxa, we propose the new genus Pseudoleucosporidium gen. nov. and the new combination Peudoleucosporidium fasciculatum comb. nov.


Subject(s)
Basidiomycota/classification , Cold Temperature , Crosses, Genetic , Basidiomycota/genetics , Basidiomycota/physiology , Cluster Analysis , DNA, Fungal/chemistry , DNA, Fungal/genetics , DNA, Ribosomal/chemistry , DNA, Ribosomal/genetics , DNA, Ribosomal Spacer/chemistry , DNA, Ribosomal Spacer/genetics , Genes, rRNA , Molecular Sequence Data , Phylogeny , RNA, Fungal/genetics , RNA, Ribosomal/genetics , Sequence Analysis, DNA
9.
Antonie Van Leeuwenhoek ; 107(2): 597-611, 2015 Feb.
Article in English | MEDLINE | ID: mdl-25515414

ABSTRACT

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.


Subject(s)
Biodiversity , Bromeliaceae/microbiology , Enzymes/analysis , Yeasts/classification , Yeasts/enzymology , Brazil , DNA, Fungal/chemistry , DNA, Fungal/genetics , Molecular Sequence Data , Seasons , Sequence Analysis, DNA , Spatial Analysis , Yeasts/isolation & purification
10.
Mol Ecol ; 23(8): 2031-45, 2014 Apr.
Article in English | MEDLINE | ID: mdl-24612382

ABSTRACT

Reticulate evolution can be a major driver of diversification into new niches, especially in disturbed habitats and at the edges of ranges. Industrial fermentation strains of yeast provide a window into these processes, but progress has been hampered by a limited understanding of the natural diversity and distribution of Saccharomyces species and populations. For example, lager beer is brewed with Saccharomyces pastorianus, an alloploid hybrid of S. cerevisiae and S. eubayanus, a species only recently discovered in Patagonia, Argentina. Here, we report that genetically diverse strains of S. eubayanus are readily isolated from Patagonia, demonstrating that the species is well established there. Analyses of multilocus sequence data strongly suggest that there are two diverse and highly differentiated Patagonian populations. The low nucleotide diversity found in the S. eubayanus moiety of hybrid European brewing strains suggests that their alleles were drawn from a small subpopulation that is closely related to one of the Patagonian populations. For the first time, we also report the rare isolation of S. eubayanus outside Patagonia, in Wisconsin, USA. In contrast to the clear population differentiation in Patagonia, the North American strains represent a recent and possibly transient admixture of the two Patagonian populations. These complex and varied reticulation events are not adequately captured by conventional phylogenetic methods and required analyses of Bayesian concordance factors and phylogenetic networks to accurately summarize and interpret. These findings show how genetically diverse eukaryotic microbes can produce rare but economically important hybrids with low genetic diversity when they migrate from their natural ecological context.


Subject(s)
Beer/microbiology , Biological Evolution , Genetic Variation , Saccharomyces/genetics , Argentina , Bayes Theorem , Chimera/genetics , DNA, Fungal/genetics , Genetics, Population , Hybridization, Genetic , Molecular Sequence Data , Multilocus Sequence Typing , Mycological Typing Techniques , Phylogeny , Saccharomyces/classification , Wisconsin
11.
Rev. argent. microbiol ; Rev. argent. microbiol;43(3): 198-202, jun.-set. 2011. graf, tab
Article in English | LILACS | ID: lil-634696

ABSTRACT

The occurrence and distribution of Xanthophyllomyces dendrorhous associated with Cyttaria hariotii parasitizing three Nothofagus species (N. dombeyi, N. antarctica and N. pumilio) in northwestern Patagonia (Argentina), as well as the factors that may affect this distribution were herein studied. Between 2000 and 2007, samples were obtained from 18 different locations. Based on physiological tests and morphological characteristics of sexual structures, 72 isolates were identified as X. dendrorhous. Representative strains were studied by MSP-PCR fingerprinting and sequence analysis of the ITS region. MSP-PCR fingerprints were similar for the newly isolated strains, and were also identical to the profiles of the strains previously found in this region. Patagonian strains appear to be a genetically uniform and distinct population, supporting the hypothesis that the association with different host species has determined genetically distinct X. dendrorhous populations worldwide. X. dendrorhous was recovered from N. dombeyi and N. antarctica. Approximately half the sampling sites and samples were positive for X. dendrorhous, but the isolation recovery rate was low. X. dendrorhous was absent in the early stages of ascostromata maturation, becoming more abundant in later stages. The present work represents a step forward in the understanding of the natural distribution and ecology of this biotechnologically relevant yeast.


Xanthophyllomyces dendrorhous (Phaffia rhodozyma) asociado a estromas de Cyttaria hariotii en bosques de Nothofagus en el noroeste de la Patagonia. Se estudió la ocurrencia y la distribución de Xanthophyllomyces dendrorhous asociado a Cyttaria hariotii en tres especies de Nothofagus (N. dombeyi, N. antarctica y N. pumilio) del noroeste de la Patagonia (Argentina), y los factores que podrían afectar esta distribución. El muestreo se realizó entre 2000 y 2007 en 18 sitios diferentes. Según las pruebas fisiológicas y las características morfológicas de las estructuras sexuales, 72 de los aislamientos obtenidos se identificaron como X. dendrorhous. Se estudiaron cepas representativas mediante la técnica de MSP-PCR fingerprinting y secuenciación de la región ITS. Los perfiles de MSP-PCR fueron similares, tanto entre los nuevos aislamientos como entre estos y los de cepas previamente obtenidas en la región. Aparentemente, las cepas patagónicas forman una población genéticamente uniforme y distinta de otras poblaciones. Esto apoya la hipótesis de que la asociación con diferentes especies hospedadoras ha determinado la diferenciación genética de X. dendrorhous en todo el mundo. X. dendrorhous se recuperó de N. dombeyi y de N. antarctica. Aproximadamente la mitad de los sitios de muestreo y de muestras fueron positivos para X. dendrorhous, pero la tasa de aislamiento fue muy baja. X. dendrorhous está ausente en estadios tempranos de maduración de ascostromas y se hace más abundante en estadios más tardíos. El presente trabajo contribuye al mejor entendimiento de la distribución natural y la ecología de esta levadura, de relevancia biotecnológica.


Subject(s)
Ascomycota/isolation & purification , Basidiomycota/isolation & purification , Fagaceae/microbiology , Argentina , Ascomycota/growth & development , Basidiomycota/genetics , Basidiomycota/growth & development , Chile , DNA Fingerprinting , DNA, Fungal/analysis , Ecosystem , Microbial Consortia , Species Specificity , Trees
12.
Proc Natl Acad Sci U S A ; 108(35): 14539-44, 2011 Aug 30.
Article in English | MEDLINE | ID: mdl-21873232

ABSTRACT

Domestication of plants and animals promoted humanity's transition from nomadic to sedentary lifestyles, demographic expansion, and the emergence of civilizations. In contrast to the well-documented successes of crop and livestock breeding, processes of microbe domestication remain obscure, despite the importance of microbes to the production of food, beverages, and biofuels. Lager-beer, first brewed in the 15th century, employs an allotetraploid hybrid yeast, Saccharomyces pastorianus (syn. Saccharomyces carlsbergensis), a domesticated species created by the fusion of a Saccharomyces cerevisiae ale-yeast with an unknown cryotolerant Saccharomyces species. We report the isolation of that species and designate it Saccharomyces eubayanus sp. nov. because of its resemblance to Saccharomyces bayanus (a complex hybrid of S. eubayanus, Saccharomyces uvarum, and S. cerevisiae found only in the brewing environment). Individuals from populations of S. eubayanus and its sister species, S. uvarum, exist in apparent sympatry in Nothofagus (Southern beech) forests in Patagonia, but are isolated genetically through intrinsic postzygotic barriers, and ecologically through host-preference. The draft genome sequence of S. eubayanus is 99.5% identical to the non-S. cerevisiae portion of the S. pastorianus genome sequence and suggests specific changes in sugar and sulfite metabolism that were crucial for domestication in the lager-brewing environment. This study shows that combining microbial ecology with comparative genomics facilitates the discovery and preservation of wild genetic stocks of domesticated microbes to trace their history, identify genetic changes, and suggest paths to further industrial improvement.


Subject(s)
Saccharomyces cerevisiae/genetics , Amino Acid Sequence , Base Sequence , Classification , Ecology , Molecular Sequence Data , Saccharomyces cerevisiae/classification
13.
Yeast ; 28(8): 619-27, 2011 Aug.
Article in English | MEDLINE | ID: mdl-21744380

ABSTRACT

The synthesis of the UV Absorbing compounds named mycosporines (MYCs) has been detected in a few basidiomycetous yeast groups. Conspicuous accumulation of mycosporine-glutaminol-glucoside (MGG) in yeasts requires photo-induction and its photoprotective function has been postulated. The distribution of the ability to produce MYCs appeared to be related to the yeast taxonomic affiliation. In view of the potential significance of MYCs in yeast taxonomy, we here studied the distribution of this trait among dimorphic basidiomycetes of the Pucciniomycotina. Of the 94 fungal species (377 strains and 33 genera) tested, almost half were MYC-positive and MGG was the main compound produced. MGG synthesis was observed for representatives of five of seven Pucciniomycotina classes, indicating that this trait is widely distributed in this group. MGG detection proved useful for the differentiation of species of the polyphyletic genera, such as Rhodotorula and Sporobolomyces, that are phylogenetically separated. MGG quantification and UV tolerance studies in Cystobasidiomycetes supported the idea that the habitat of origin of each strains is important in the level of MGG synthesis and that MYCs have a photoprotective function in yeasts. The taxonomic value of this trait in fungal systematics is discussed.


Subject(s)
Basidiomycota/classification , Basidiomycota/metabolism , Cyclohexanols/metabolism , Glucosides/metabolism , Phylogeny , Basidiomycota/genetics , Basidiomycota/radiation effects , Molecular Sequence Data , Ultraviolet Rays
14.
Rev Argent Microbiol ; 43(3): 226-32, 2011.
Article in English | MEDLINE | ID: mdl-22430994

ABSTRACT

The occurrence and distribution of Xanthophyllomyces dendrorhous associated with Cyttaria hariotii parasitizing three Nothofagus species (N. dombeyi, N. antarctica and N. pumilio) in northwestern Patagonia (Argentina), as well as the factors that may affect this distribution were herein studied. Between 2000 and 2007, samples were obtained from 18 different locations. Based on physiological tests and morphological characteristics of sexual structures, 72 isolates were identified as X. dendrorhous. Representative strains were studied by MSP-PCR fingerprinting and sequence analysis of the ITS region. MSP-PCR fingerprints were similar for the newly isolated strains, and were also identical to the profiles of the strains previously found in this region. Patagonian strains appear to be a genetically uniform and distinct population, supporting the hypothesis that the association with different host species has determined genetically distinct X. dendrorhous populations worldwide. X. dendrorhous was recovered from N. dombeyi and N. antarctica. Approximately half the sampling sites and samples were positive for X. dendrorhous, but the isolation recovery rate was low. X. dendrorhous was absent in the early stages of ascostromata maturation, becoming more abundant in later stages. The present work represents a step forward in the understanding of the natural distribution and ecology of this biotechnologically relevant yeast.


Subject(s)
Ascomycota/isolation & purification , Basidiomycota/isolation & purification , Fagaceae/microbiology , Argentina , Ascomycota/growth & development , Basidiomycota/genetics , Basidiomycota/growth & development , Chile , DNA Fingerprinting , DNA, Fungal/analysis , Ecosystem , Microbial Consortia , Species Specificity , Trees
15.
Int J Syst Evol Microbiol ; 60(Pt 9): 2251-2256, 2010 Sep.
Article in English | MEDLINE | ID: mdl-19880630

ABSTRACT

A basidiomycetous yeast, strain CRUB 1032(T), which formed salmon-pink colonies, was isolated from glacial meltwater in Patagonia, Argentina. Morphological, physiological and biochemical characterization indicated that this strain belonged to the genus Rhodotorula. Molecular taxonomic analysis based on the 26S rDNA D1/D2 domain and internal transcribed spacer region sequences showed that strain CRUB 1032(T) represents an undescribed yeast species, for which the name Rhodotorula meli sp. nov. is proposed (type strain is CRUB 1032(T)=CBS 10797(T)=JCM 15319(T)). Phylogenetic analysis showed that Rhodotorula lamellibrachii was the closest known species, which, together with R. meli, formed a separate cluster related to the Sakaguchia clade within the Cystobasidiomycetes. Additional Patagonian yeast isolates of the class Cystobasidiomycetes are also investigated in the present work.


Subject(s)
Ice Cover/microbiology , Rhodotorula/classification , Rhodotorula/isolation & purification , Argentina , DNA, Fungal/genetics , DNA, Ribosomal Spacer/genetics , Molecular Sequence Data , Mycological Typing Techniques , Phylogeny , RNA, Ribosomal/genetics , Rhodotorula/genetics
16.
FEMS Microbiol Ecol ; 69(3): 353-62, 2009 Sep.
Article in English | MEDLINE | ID: mdl-19624739

ABSTRACT

Mountain lakes located at a high elevation are typically exposed to high UV radiation (UVR). Little is known about the ecology and diversity of yeasts inhabiting these extreme environments. We studied yeast occurrence (with special emphasis on those producing carotenoid pigments) at five high-altitude (>1400 m a.s.l.) water bodies located in the Nahuel Huapi National Park (Bariloche, Argentina). Isolates were identified using a polyphasic approach. Production of photoprotective compounds (carotenoids and mycosporines) by yeast isolates, and UVB resistance of selected species were studied. All water samples contained viable yeast cells in variable numbers, generally ranging from 49 to 209 cells L(-1). A total of 24 yeast species was found; at least four represented novel species. Carotenogenic yeasts prevailed in lakes with low water conductivity and higher transparency and chlorophyll a levels. Apparently, the ability to produce photoprotective compounds in yeasts was related to the transparency of mountain lake waters, and strains from more transparent waters developed increased UVB resistance. Our results indicate that UVR is an important environmental factor affecting the yeast community structure in aquatic habitats.


Subject(s)
Fresh Water/microbiology , Ultraviolet Rays , Water Microbiology , Yeasts/radiation effects , Argentina , Biodiversity , DNA, Fungal/genetics , RNA, Ribosomal/genetics , Yeasts/classification , Yeasts/genetics , Yeasts/isolation & purification
17.
Int J Syst Evol Microbiol ; 59(Pt 3): 622-30, 2009 Mar.
Article in English | MEDLINE | ID: mdl-19244450

ABSTRACT

Here, we report on two novel sexual basidiomycetous red yeast species of the genus Cystofilobasidium. Cystofilobasidium lacus-mascardii sp. nov. is based on sexually compatible strains isolated from Lake Mascardi, an ultraoligotrophic lake in north-western Patagonia, Argentina. Following the discovery of the first isolate of this species, additional (sexually compatible) strains were isolated using a selective medium containing erythritol as the sole source of carbon. The second novel species corresponds to the sexual state of Cryptococcus macerans. In spite of accounts over the last 20 years of sexually compatible strains of this species, the complete life has never been observed. We provide evidence of a Cystofilobasidium-like basidial stage with teliospores and slender holobasidia, based on the study of self-fertile (homothallic) and self-sterile (heterothallic) isolates of Cryptococcus macerans. A revised molecular phylogeny of the genus Cystofilobasidium is presented and the most salient features of Cystofilobasidium lacus-mascardii sp. nov. (type strain CBS 10642(T) =PYCC 5819(T) =CRUB 1046(T)) and Cystofilobasidium macerans sp. nov. (type strain CBS 10757(T)) are discussed and compared with those of the remaining species in the genus. Information on additional Patagonian isolates belonging to the Cystofilobasidiales is also included in this report.


Subject(s)
Basidiomycota/classification , Basidiomycota/physiology , Cryptococcus/physiology , Fresh Water/microbiology , Argentina , Basidiomycota/genetics , Basidiomycota/isolation & purification , Cryptococcus/classification , Culture Media , DNA Fingerprinting/methods , DNA, Fungal/analysis , DNA, Ribosomal Spacer/analysis , Molecular Sequence Data , Mycological Typing Techniques , Phenotype , Phylogeny , Polymerase Chain Reaction , RNA, Ribosomal, 5.8S/genetics , Sequence Analysis, DNA , Species Specificity
18.
J Basic Microbiol ; 48(2): 93-8, 2008 Apr.
Article in English | MEDLINE | ID: mdl-18383231

ABSTRACT

The yeast species Rhodotorula mucilaginosa is considered to be ubiquitous due to its world-wide distribution in terrestrial, freshwater and marine habitats, and to its ability to colonize a large variety of substrates. In this paper we assess the phenotypic and genetic variability of environmental isolates of R. mucilaginosa collected from natural and artificial environments in Patagonia, Argentina. A total of 97 strains were studied and sorted into three groups based on MSP-PCR fingerprinting results: A, which comprised 90% of the strains, including the type strain; and B and C which included 2 and 8% of the strains, respectively. The D1D2 sequencing did not differentiate any of the 3 groups, while ITS sequencing validated the existence of group C. This group was composed of Patagonian isolates of diverse origin. DNA-DNA reassociation studies confirmed the existence of significant genetic differences between group C and the type strain. In this study, which is the first on the intraspecific variability of a large set of R. mucilaginosa isolates, a considerable phenotypic and genetic heterogeneity was observed, however such differences were not enough to refute co-specificity. The study of Patagonian isolates allowed the detection of a genetically distinct group of R. mucilaginosa strains.


Subject(s)
Carotenoids/biosynthesis , DNA, Fungal/genetics , Rhodotorula/genetics , Rhodotorula/isolation & purification , Argentina , Environmental Microbiology , Mycological Typing Techniques/methods , Mycology/methods , Polymerase Chain Reaction , Rhodotorula/classification , Water Microbiology
19.
Appl Environ Microbiol ; 73(4): 1120-5, 2007 Feb.
Article in English | MEDLINE | ID: mdl-17189439

ABSTRACT

Phaffia rhodozyma (sexual form, Xanthophyllomyces dendrorhous) is a basidiomycetous yeast that has been found in tree exudates in the Northern Hemisphere at high altitudes and latitudes. This yeast produces astaxanthin, a carotenoid pigment with biotechnological importance because it is used in aquaculture for fish pigmentation. We isolated X. dendrorhous from the Southern Hemisphere (Patagonia, Argentina), where it was associated with fruiting bodies of Cyttaria hariotii, an ascomycetous parasite of Nothofagus trees. We compared internal transcribed spacer (ITS)-based phylogenies of P. rhodozyma and its tree host (Betulaceae, Corneaceae, Fagaceae, and Nothofagaceae) and found them to be generally concordant, suggesting that different yeast lineages colonize different trees and providing an explanation for the phylogenetic distance observed between the type strains of P. rhodozyma and X. dendrorhous. We hypothesize that the association of Xanthophyllomyces with Cyttaria derives from a previous association of the yeast with Nothofagus, and the sister relationship between Nothofagaceae and Betulaceae plus Fagaceae correlates with the phylogeny of X. dendrorhous strains originating from these three plant families. The two most basal strains of X. dendrorhous are those isolated from Cornus, an ancestral genus in the phylogenetic analysis of the host trees. Thus, we question previous conclusions that P. rhodozyma and X. dendrorhous represent different species since the polymorphisms detected in the ITS and intergenic spacer sequences can be attributed to intraspecific variation associated with host specificity. Our study provides a deeper understanding of Phaffia biogeography, ecology, and molecular phylogeny. Such knowledge is essential for the comprehension of many aspects of the biology of this organism and will facilitate the study of astaxanthin production within an evolutionary and ecological framework.


Subject(s)
Basidiomycota/classification , Base Sequence , Basidiomycota/genetics , Host-Parasite Interactions , Molecular Sequence Data , Mycological Typing Techniques , Phylogeny , Yeasts/classification , Yeasts/genetics
20.
Int J Syst Evol Microbiol ; 55(Pt 1): 503-509, 2005 Jan.
Article in English | MEDLINE | ID: mdl-15653924

ABSTRACT

During a survey of carotenogenic yeasts carried out in north-western Patagonia (Argentina), several ballistoconidia-producing strains belonging to the order Sporidiobolales were isolated from aquatic environments. Five strains were found to represent two novel species, for which the names Sporidiobolus longiusculus and Sporobolomyces patagonicus are proposed, with CBS 9654T (=PYCC 5818T=CRUB 1044T) and CBS 9657T (=PYCC 5817T=CRUB 1038T) as the type strains, respectively. The elongated basidia, which are five to six times longer that those of the remaining species of the genus Sporidiobolus, are a particular micromorphological feature of Sporidiobolus longiusculus. On the basis of the sequences of the D1/D2 domains of the 26S rRNA gene, the species most closely related to Sporidiobolus longiusculus is Sporobolomyces bannaensis, whereas Sporobolomyces marcillae is the closest relative of Sporobolomyces patagonicus. Complete internal transcribed spacer sequence analysis confirmed the separate position of Sporidiobolus longiusculus, whereas for Sporobolomyces patagonicus no nucleotide differences were found with respect to Sporidiobolus pararoseus CBS 491T. Negative mating experiments between strains of Sporobolomyces patagonicus and strains of Sporidiobolus pararoseus together with the low DNA-DNA reassociation values for the type strains of the two species validated the proposal of Sporobolomyces patagonicus as a distinct species. Information on additional Patagonian Sporobolomyces isolates is also included in this report.


Subject(s)
Basidiomycota/classification , Water Microbiology , Argentina , Basidiomycota/genetics , Basidiomycota/isolation & purification , DNA, Fungal/analysis , DNA, Ribosomal Spacer/analysis , Molecular Sequence Data , Mycological Typing Techniques , RNA, Ribosomal/genetics , RNA, Ribosomal, 5.8S/genetics , Sequence Analysis, DNA
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