Your browser doesn't support javascript.
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 1.223
Filtrar
1.
Syst Biol ; 69(1): 17-37, 2020 01 01.
Artigo em Inglês | MEDLINE | ID: mdl-31062852

RESUMO

Resolving deep divergences in the tree of life is challenging even for analyses of genome-scale phylogenetic data sets. Relationships between Basidiomycota subphyla, the rusts and allies (Pucciniomycotina), smuts and allies (Ustilaginomycotina), and mushroom-forming fungi and allies (Agaricomycotina) were found particularly recalcitrant both to traditional multigene and genome-scale phylogenetics. Here, we address basal Basidiomycota relationships using concatenated and gene tree-based analyses of various phylogenomic data sets to examine the contribution of several potential sources of bias. We evaluate the contribution of biological causes (hard polytomy, incomplete lineage sorting) versus unmodeled evolutionary processes and factors that exacerbate their effects (e.g., fast-evolving sites and long-branch taxa) to inferences of basal Basidiomycota relationships. Bayesian Markov Chain Monte Carlo and likelihood mapping analyses reject the hard polytomy with confidence. In concatenated analyses, fast-evolving sites and oversimplified models of amino acid substitution favored the grouping of smuts with mushroom-forming fungi, often leading to maximal bootstrap support in both concatenation and coalescent analyses. On the contrary, the most conserved data subsets grouped rusts and allies with mushroom-forming fungi, although this relationship proved labile, sensitive to model choice, to different data subsets and to missing data. Excluding putative long-branch taxa, genes with high proportions of missing data and/or with strong signal failed to reveal a consistent trend toward one or the other topology, suggesting that additional sources of conflict are at play. While concatenated analyses yielded strong but conflicting support, individual gene trees mostly provided poor support for any resolution of rusts, smuts, and mushroom-forming fungi, suggesting that the true Basidiomycota tree might be in a part of tree space that is difficult to access using both concatenation and gene tree-based approaches. Inference-based assessments of absolute model fit strongly reject best-fit models for the vast majority of genes, indicating a poor fit of even the most commonly used models. While this is consistent with previous assessments of site-homogenous models of amino acid evolution, this does not appear to be the sole source of confounding signal. Our analyses suggest that topologies uniting smuts with mushroom-forming fungi can arise as a result of inappropriate modeling of amino acid sites that might be prone to systematic bias. We speculate that improved models of sequence evolution could shed more light on basal splits in the Basidiomycota, which, for now, remain unresolved despite the use of whole genome data.


Assuntos
Basidiomycota/classificação , Classificação/métodos , Modelos Genéticos , Filogenia , Basidiomycota/genética , Genes Fúngicos/genética
2.
Int J Syst Evol Microbiol ; 69(12): 3728-3739, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31693471

RESUMO

The Arxan-Chaihe volcanic field of the Da Hinggan mountains in north-East PR China hosts various typical crater lakes. In this study we performed a yeast diversity survey using water sampled from five crater lakes and a total of 122 yeast strains belonging to 33 species of 25 genera were isolated. Three strains, TFL1-L, TFL2B and ATC4C, were identified as three novel species belonging to the Tremellomycetes based on a multiple gene phylogeny and on the comparison of physiological data. A phylogenetic study employing the sequences of seven genes indicated that the new species were more related to three separated phylogenetic lineages of the Tremellomycetes and their closest relatives were Heterocephalacria arrabidensis, Phaeotremella skinneri and Solicoccozyma keelungensis. The divergence values of the D1/D2 domain of LSU sequences of strains TFL1-L, TFL2B and ATC4C from H. arrabidensis CBS 8678T, P. skinneri CBS 5029T and S. keelungensisSN-82T were 4.8,3.4,2.1 %, respectively. The divergence values of the sequences of ITS regions between strains TFL1-L, TFL2B and ATC4C and their close relatives (H. arrabidensis, P. skinneri and S. keelungensis) were 16.1, 5.9 and 8.1  %, respectively. Moreover, the three strains differed from their phylogenetic neighbours by the ability to grow on distinct carbon and nitrogen sources. On the basis of these findings, it is suggested that these strains represent three novel species for which the names Heterocephalacria sinensis sp. nov. (holotype CGMCC 2.5595), Phaeotremella lacus sp. nov. (holotype CGMCC 2.5580) and Solicoccozyma aquatica sp. nov. (holotype CGMCC 2.5574) are proposed.


Assuntos
Basidiomycota/classificação , Lagos/microbiologia , Filogenia , Basidiomycota/isolamento & purificação , China , DNA Fúngico/genética , DNA Espaçador Ribossômico/genética , Técnicas de Tipagem Micológica , Análise de Sequência de DNA
3.
BMC Genomics ; 20(1): 765, 2019 Oct 22.
Artigo em Inglês | MEDLINE | ID: mdl-31640544

RESUMO

BACKGROUND: Hypsizygus marmoreus, a high value commercialized edible mushroom is widely cultivated in East Asia, and has become one of the most popular edible mushrooms because of its rich nutritional and medicinal value. Mitochondria are vital organelles, and play various essential roles in eukaryotic cells. RESULTS: In this study, we provide the Hypsizygus marmoreus mitochondrial (mt) genome assembly: the circular sequence is 102,752 bp in size and contains 15 putative protein-coding genes, 2 ribosomal RNAs subunits and 28 tRNAs. We compared the mt genomes of the 27 fungal species in the Pezizomycotina and Basidiomycotina subphyla, with the results revealing that H. marmoreus is a sister to Tricholoma matsutake and the phylogenetic distribution of this fungus based on the mt genome. Phylogenetic analysis shows that Ascomycetes mitochondria started to diverge earlier than that of Basidiomycetes and supported the robustness of the hyper metric tree. The fungal sequences are highly polymorphic and gene order varies significantly in the dikarya data set, suggesting a correlation between the gene order and divergence time in the fungi mt genome. To detect the mt genome variations in H. marmoreus, we analyzed the mtDNA sequences of 48 strains. The phylogeny and variation sited type statistics of H. marmoreus provide clear-cut evidence for the existence of four well-defined cultivations isolated lineages, suggesting female ancestor origin of H. marmoreus. Furthermore, variations on two loci were further identified to be molecular markers for distinguishing the subgroup containing 32 strains of other strains. Fifteen conserved protein-coding genes of mtDNAs were analyzed, with fourteen revealed to be under purifying selection in the examined fungal species, suggesting the rapid evolution was caused by positive selection of this gene. CONCLUSIONS: Our studies have provided new reference mt genomes and comparisons between species and intraspecies with other strains, and provided future perspectives for assessing diversity and origin of H. marmoreus.


Assuntos
Agaricales/genética , Evolução Molecular , Genoma Mitocondrial/genética , Agaricales/classificação , Ascomicetos/classificação , Ascomicetos/genética , Basidiomycota/classificação , Basidiomycota/genética , DNA Mitocondrial/genética , Proteínas Fúngicas/genética , Ordem dos Genes , Variação Genética , Filogenia , Seleção Genética , Especificidade da Espécie
4.
BMC Genomics ; 20(1): 723, 2019 Oct 09.
Artigo em Inglês | MEDLINE | ID: mdl-31597570

RESUMO

BACKGROUND: Gymnosporangium spp. are fungal plant pathogens causing rust disease and most of them are known to infect two different host plants (heteroecious) with four spore stages (demicyclic). In the present study, we sequenced the transcriptome of G. japonicum teliospores on its host plant Juniperus chinensis and we performed comparison to the transcriptomes of G. yamadae and G. asiaticum at the same life stage, that happens in the same host but on different organs. RESULTS: Functional annotation for the three Gymnosporangium species showed the expression of a conserved genetic program with the top abundant cellular categories corresponding to energy, translation and signal transduction processes, indicating that this life stage is particularly active. Moreover, the survey of predicted secretomes in the three Gymnosporangium transcriptomes revealed shared and specific genes encoding carbohydrate active enzymes and secreted proteins of unknown function that could represent candidate pathogenesis effectors. A transcript encoding a hemicellulase of the glycoside hydrolase 26 family, previously identified in other rust fungi, was particularly highly expressed suggesting a general role in rust fungi. The comparison between the transcriptomes of the three Gymnosporangium spp. and selected Pucciniales species in different taxonomical families allowed to identify lineage-specific protein families that may relate to the biology of teliospores in rust fungi. Among clustered gene families, 205, 200 and 152 proteins were specifically identified in G. japonicum, G. yamadae and G. asiaticum, respectively, including candidate effectors expressed in teliospores. CONCLUSIONS: This comprehensive comparative transcriptomics study of three Gymnosporangium spp. identified gene functions and metabolic pathways particularly expressed in teliospores, a stage of the life cycle that is mostly overlooked in rust fungi. Secreted protein encoding transcripts expressed in teliospores may reveal new candidate effectors related to pathogenesis. Although this spore stage is not involved in host plant infection but in the production of basidiospores infecting plants in the Amygdaloideae, we speculate that candidate effectors may be expressed as early as the teliospore stage for preparing further infection by basidiospores.


Assuntos
Basidiomycota/genética , Proteínas Fúngicas/genética , Perfilação da Expressão Gênica/métodos , Traqueófitas/microbiologia , Basidiomycota/classificação , Basidiomycota/patogenicidade , Regulação Fúngica da Expressão Gênica , Estágios do Ciclo de Vida , Família Multigênica , Filogenia , Análise de Sequência de RNA , Esporos Fúngicos/genética
5.
BMC Biol ; 17(1): 65, 2019 08 13.
Artigo em Inglês | MEDLINE | ID: mdl-31405370

RESUMO

BACKGROUND: Effective disease management depends on timely and accurate diagnosis to guide control measures. The capacity to distinguish between individuals in a pathogen population with specific properties such as fungicide resistance, toxin production and virulence profiles is often essential to inform disease management approaches. The genomics revolution has led to technologies that can rapidly produce high-resolution genotypic information to define individual variants of a pathogen species. However, their application to complex fungal pathogens has remained limited due to the frequent inability to culture these pathogens in the absence of their host and their large genome sizes. RESULTS: Here, we describe the development of Mobile And Real-time PLant disEase (MARPLE) diagnostics, a portable, genomics-based, point-of-care approach specifically tailored to identify individual strains of complex fungal plant pathogens. We used targeted sequencing to overcome limitations associated with the size of fungal genomes and their often obligately biotrophic nature. Focusing on the wheat yellow rust pathogen, Puccinia striiformis f.sp. tritici (Pst), we demonstrate that our approach can be used to rapidly define individual strains, assign strains to distinct genetic lineages that have been shown to correlate tightly with their virulence profiles and monitor genes of importance. CONCLUSIONS: MARPLE diagnostics enables rapid identification of individual pathogen strains and has the potential to monitor those with specific properties such as fungicide resistance directly from field-collected infected plant tissue in situ. Generating results within 48 h of field sampling, this new strategy has far-reaching implications for tracking plant health threats.


Assuntos
Basidiomycota/isolamento & purificação , Testes Diagnósticos de Rotina/métodos , Doenças das Plantas/microbiologia , Sistemas Automatizados de Assistência Junto ao Leito , Basidiomycota/classificação , Doenças das Plantas/classificação
6.
Int J Syst Evol Microbiol ; 69(11): 3385-3391, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31368884

RESUMO

During a survey of yeast populations associated with grape and apple musts used for wine and cider fermentation, respectively, six pink-coloured ballistoconidia-forming yeasts belonging to the order Sporidiobolales (Basidiomycota) were isolated. Phylogenetic analysis inferred using sequences of the internal transcribed spacer (ITS), the D1/D2 domain of the large subunit rRNA gene, the small subunit (SSU) rRNA gene and DNA-directed RNA polymerase II subunit (RPB2) indicated that the six isolates were separated in two novel species. One of the new species, Sporobolomyces agrorum sp. nov., isolated from grape must, had Sporobolomyces roseus and Sporobolomyces metaroseus as its closest relatives, but showed four/two and 16 nucleotide substitutions in the D1/D2 and ITS regions, respectively, to these two species. The other novel species, Sporobolomyces sucorum sp. nov., was found in apple must and was closely related to Sporobolomyces pararoseus and Sporobolomyces patagonicus, but showed two/three and five substitutions in those two regions for its closest relatives. We detected additional representatives of this species, most of them isolated from grapes whose sequences were already available on public databases. A sexual stage could not be observed for the novel species.


Assuntos
Basidiomycota/classificação , Malus/microbiologia , Filogenia , Vitis/microbiologia , Basidiomycota/isolamento & purificação , DNA Fúngico/genética , DNA Espaçador Ribossômico/genética , Itália , Técnicas de Tipagem Micológica , Análise de Sequência de DNA , Esporos Fúngicos , Leveduras/classificação , Leveduras/isolamento & purificação
7.
World J Microbiol Biotechnol ; 35(7): 108, 2019 Jul 02.
Artigo em Inglês | MEDLINE | ID: mdl-31267227

RESUMO

A total of 191 yeasts were isolated from 197 samples collected from eight estuarine mangrove forests along four different coastlines of Thailand (Andaman Sea and the East, North and West coasts of the Gulf of Thailand). Of these, 178 isolates were identified as 32 species in 16 genera of Ascomycota, 12 species in nine genera of Basidiomycota, and 13 isolates as potential new species, respectively. Mangroves located along the Andaman Sea coastline had a higher yeast diversity at the species and genera levels than those along the Gulf of Thailand. Kluyveromyces siamensis was the most frequently isolated species, whilst Candida tropicalis was the only species isolated at all eight sites. Screening isolated yeast strains belonging to genera previously reported as oleaginous yeast plus the 13 potential new species, revealed two oleaginous strains, Rhodotorula sphaerocarpa 11-14.4 and Saitozyma podzolica 11-11.3.1. Both of these strains were isolated from the same mangrove forest on the Andaman Sea coastline. They could accumulate lipid when suspended in glucose solution without any supplementation, while the fatty acid composition and oil profile of Rh. sphaerocarpa 11-14.4 and Sait. podzolica 11-11.3.1 were similar to vegetable oil and cocoa butter, respectively.


Assuntos
Filogenia , Áreas Alagadas , Leveduras/classificação , Leveduras/isolamento & purificação , Ascomicetos/química , Ascomicetos/classificação , Ascomicetos/isolamento & purificação , Basidiomycota/química , Basidiomycota/classificação , Basidiomycota/isolamento & purificação , Biodiversidade , Biocombustíveis , DNA Fúngico/análise , DNA Fúngico/isolamento & purificação , Gorduras na Dieta , Ácidos Graxos/análise , Glucose/metabolismo , Metabolismo dos Lipídeos , Lipídeos/análise , Tipagem Molecular , Óleos Vegetais , RNA Ribossômico/genética , Análise de Sequência , Tailândia , Leveduras/química , Leveduras/genética
8.
Microsc Res Tech ; 82(10): 1700-1705, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31267586

RESUMO

Himalayan range of Pakistan is one of the diversity rich hotspots of the world. Many areas are yet to be explored here to discover new species of organisms including fungi. During present research, Swat District of Pakistan was explored for fungal diversity. One new species of mushroom Russula swatica (Russulales) is described from Himalayan range of Pakistan and analyzed by light microscopy and scanning electron microscopy as well as by molecular markers. A comprehensive description, photographs, and comparisons with morphologically similar and phylogenetically related species are provided. Conclusions of its phylogenetic relationships within the genus are provided based on the sequence of the nuclear internal transcribed spacer region.


Assuntos
Basidiomycota/classificação , Basidiomycota/citologia , Filogenia , Basidiomycota/genética , Basidiomycota/ultraestrutura , DNA Fúngico/química , DNA Fúngico/genética , DNA Espaçador Ribossômico/química , DNA Espaçador Ribossômico/genética , Microscopia , Microscopia Eletrônica de Varredura , Paquistão , Análise de Sequência de DNA
9.
Int J Syst Evol Microbiol ; 69(9): 2828-2833, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31274406

RESUMO

Strain SYSU-17, representing a novel acid-tolerant yeast species which can grow at pH 2.0 weakly, was isolated from acid mine drainage collected in a tailing impoundment of the Fankou Lead/Zinc Mine, Guangdong Province, PR China. Phylogenetic analysis of strain SYSU-17 based on the internal transcribed spacer (ITS) region and the D1/D2 domains of the large subunit ribosomal RNA (LSU rRNA) gene suggested that strain SYSU-17 was a novel species belonging to the genus Spencerozyma (class Microbotryomycetes, subphylum Pucciniomycotina). It differed from the type strain of the closest related species, Spencerozyma crocea CBS 2029T, by 0.7 % sequence divergence (three gaps and one nucleotide substitution out of 594 bp) in the D1/D2 domains of the LSU rRNA gene and 7.6 % sequence divergence (32 gaps and 22 nucleotide substitutions out of 714 bp) in the ITS region. In contrast to the physiological properties of S. crocea, the novel yeast species was unable to assimilate galactose, d-ribose, xylitol, succinate, d-xylose, ethanol, nitrate and nitrite. The name Spencerozyma acididurans sp. nov. is proposed and SYSU-17 is designated as the holotype.


Assuntos
Basidiomycota/classificação , Mineração , Filogenia , Microbiologia da Água , Ácidos , Basidiomycota/isolamento & purificação , China , DNA Fúngico/genética , DNA Espaçador Ribossômico/genética , Técnicas de Tipagem Micológica , Análise de Sequência de DNA
10.
Artigo em Inglês | MEDLINE | ID: mdl-31337007

RESUMO

Volatile fungal metabolites are responsible for various odors and may contribute to a "sick building syndrome" (SBS) with a negative effect on the heath of building. The authors have attempted to fill the research gaps by analyzing microbial volatile organic compounds (MVOCs) originating from representatives of the Basidiomycetes class that grow on wood-polymer composite (WPC) boards. WPCs have been analyzed as a material exposed to biodeterioration. Indoor air quality (IAQ) is affected by the increased use of WPCs inside buildings, and is becoming a highly relevant research issue. The emission profiles of MVOCs at various stages of WPC decay have been demonstrated in detail for Coniophora puteana and Poria placenta, and used to set the European industrial standards for wood-decay fungi. Differences in the production of MVOCs among these species of fungi have been detected using the thermal desorption-gas chromatography/mass spectrometry (TD-GC/MS) method. This study identifies the production of alcohols, aldehydes, ketones, carboxylic acids and other compounds during one month of fungal growth. The identified level of metabolites indicates a relation between the level of air pollution and condition of the WPC material, which may become part of IAQ quantification in the future. The study points to the species-specific compounds for representatives of brown and white-rot fungi and the compounds responsible for their odor. In this study, 1-Octen-3-ol was indicated as a marker for their active growth, which is also associated with SBS. The proposed experimental set-up and data analysis are a simple and convenient way to obtain emission profiles of MVOCs from microbes growing on different materials.


Assuntos
Basidiomycota/metabolismo , Cromatografia Gasosa-Espectrometria de Massas/métodos , Compostos Orgânicos Voláteis/química , Madeira/química , Poluição do Ar em Ambientes Fechados/análise , Basidiomycota/classificação , Basidiomycota/crescimento & desenvolvimento , Síndrome do Edifício Doente , Especificidade da Espécie
11.
World J Microbiol Biotechnol ; 35(7): 113, 2019 Jul 09.
Artigo em Inglês | MEDLINE | ID: mdl-31289918

RESUMO

Camellia taliensis (W. W. Smith) Melchior is a wild tea plant endemic from the west and southwest of Yunnan province of China to the north of Myanmar and is used commonly to produce tea by the local people of its growing areas. Its chemical constituents are closely related to those of C. sinensis var. assamica, a widely cultivated tea plant. In this study, the α diversity and phylogeny of endophytic fungi in the branches of C. taliensis were explored for the first time. A total of 160 fungal strains were obtained and grouped into 42 species from 29 genera, which were identified based on rDNA internal transcribed spacer sequence analysis. Diversity analysis showed that the endophytic fungal community of the branches of C. taliensis had high species richness S (42), Margalef index D' (8.0785), Shannon-Wiener index H' (2.8494), Simpson diversity index DS (0.8891), PIE index (0.8947) and evenness Pielou index J (0.7623) but a low dominant index λ (0.1109). By contrast, that in the branches of C. taliensis had abundant species and high species evenness. Diaporthe tectonigena, Acrocalymma sp. and Colletotrichum magnisporum were the dominant endophytic fungi. The phylogenetic tree was established by maximum parsimony analysis, and the 11 orders observed for endophytic fungi belonging to Ascomycota and Basidiomycota were grouped into 4 classes.


Assuntos
Camellia/microbiologia , Endófitos/classificação , Endófitos/isolamento & purificação , Fungos/classificação , Fungos/isolamento & purificação , Filogenia , Chá , Ascomicetos/classificação , Ascomicetos/genética , Ascomicetos/isolamento & purificação , Basidiomycota/classificação , Basidiomycota/genética , Basidiomycota/isolamento & purificação , Biodiversidade , China , Análise por Conglomerados , DNA Ribossômico/genética , Endófitos/genética , Fungos/genética , Mianmar , Análise de Sequência
12.
Int J Syst Evol Microbiol ; 69(9): 2823-2827, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31259676

RESUMO

Strains of yeast were isolated under a nitrogen-depleted culture condition from decaying tree bark (strain N-12.1) and from mangrove forest water (strain 1-7W.1) sampled at different locations within a mangrove forest site in Ranong province, Thailand. They were found to be genetically and phenotypically different from any currently recognised yeast species. Phylogenetic analysis of nucleotide sequence of three genes, the internal transcribed spacer region 1 and 2 plus 5.8S ribosomal RNA gene (ITS), D1/D2 domain of the large subunit ribosomal RNA gene (LSU D1/D2) and the small subunit of the ribosomal RNA gene (SSU), revealed that these two strains were related to but distinguished from Heterocephalacriaarrabidensis. Several distinct physiological characteristics of these two strains were detected, namely inability to assimilate glycerol, dl-lactic acid, succinic acid, citric acid, d-gluconic acid, and ability to grow well at 25 °C, which were different from those of H. arrabidensis. Accordingly, the name Heterocephalacria mucosa sp. nov., is proposed to accommodate this novel species. The MycoBank number is MB 828624.


Assuntos
Basidiomycota/classificação , Filogenia , Casca de Planta/microbiologia , Basidiomycota/isolamento & purificação , DNA Fúngico/genética , DNA Espaçador Ribossômico/genética , Técnicas de Tipagem Micológica , RNA Ribossômico 5,8S , Análise de Sequência de DNA , Tailândia , Áreas Alagadas
13.
Z Naturforsch C J Biosci ; 74(7-8): 201-210, 2019 Jul 26.
Artigo em Inglês | MEDLINE | ID: mdl-31199781

RESUMO

Two edible, cultivable mushroom species of the family Strophariaceae, Kuehneromyces mutabilis (sheathed woodtuft) and Hypholoma capnoides (conifer tuft), were studied using proton nuclear magnetic resonance metabolomic approach. The variation in the metabolites of the two species and their metabolic behaviour regarding caps and stipes and different collection sites were analysed by multivariate analysis methods. Altogether 169 cap and stipe samples of the mushrooms were investigated. The clearest difference between the species was in the sugar composition, which was more diverse in H. capnoides. When mushroom samples collected from different locations were compared, more variance was found in H. capnoides, whereas K. mutabilis appeared more homogeneous as a species. As far as the caps and stipes were concerned, in both species the amount of α-α-trehalose was clearly higher in the stipes, and the caps contained a larger proportion of the amino acids and organic acids.


Assuntos
Basidiomycota/metabolismo , Metaboloma , Basidiomycota/química , Basidiomycota/classificação , Espectroscopia de Ressonância Magnética
14.
Genes (Basel) ; 10(6)2019 06 04.
Artigo em Inglês | MEDLINE | ID: mdl-31167502

RESUMO

One of the most commonly encountered species in the small basidiomycetous sub-phylum Wallemiomycotina is Wallemia mellicola, a xerotolerant fungus with a widespread distribution. To investigate the population characteristics of the species, whole genomes of twenty-five strains were sequenced. Apart from identification of four strains of clonal origin, the distances between the genomes failed to reflect either the isolation habitat of the strains or their geographical origin. Strains from different parts of the world appeared to represent a relatively homogenous and widespread population. The lack of concordance between individual gene phylogenies and the decay of linkage disequilibrium indicated that W. mellicola is at least occasionally recombining. Two versions of a putative mating-type locus have been found in all sequenced genomes, each present in approximately half of the strains. W. mellicola thus appears to be capable of (sexual) recombination and shows no signs of allopatric speciation or specialization to specific habitats.


Assuntos
Basidiomycota/genética , Especiação Genética , Genoma/genética , Genômica , Basidiomycota/classificação , Ecossistema , Filogenia , Filogeografia , Recombinação Genética/genética
15.
Mycorrhiza ; 29(4): 397-401, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-31175441

RESUMO

In 2017 a North American fungus, Rhizopogon pseudoroseolus (Boletales, Basidiomycota), formerly known in Oceania as only occurring in New Zealand, was found for the first time in South Australia. The morphological identification of collected specimens was confirmed using an internal transcribed spacer barcoding approach. In this study, the biogeography of R. pseudoroseolus is also presented, based on sporocarp and ectomycorrhiza records. Species distribution modeling implemented in MaxEnt was used to estimate the distribution of the potential range of R. pseudoroseolus in Australia and New Zealand. The obtained model illustrates, in the background of climatic variables and distribution of a symbiotic partner, its wide range of suitable habitats in New Zealand, South-East Australia, and Tasmania. Precipitation of the coldest quarters and annual mean temperature are important factors influencing the potential distribution of the fungus. The occurrence of Pinus radiata, the ectomycorrhizal partner of R. pseudoroseolus, is also an important factor limiting expansion of the fungus' invasion range.


Assuntos
Basidiomycota/isolamento & purificação , Basidiomycota/fisiologia , Pinus/microbiologia , Simbiose , Austrália , Basidiomycota/classificação , Basidiomycota/genética , Clima , Nova Zelândia , América do Norte , Filogenia , Pinus/fisiologia , Tasmânia
16.
Int J Mol Sci ; 20(12)2019 Jun 13.
Artigo em Inglês | MEDLINE | ID: mdl-31200551

RESUMO

Tremellomycetes, a fungal class in the subphylum Agaricomycotina, contain well-known opportunistic and emerging human pathogens. The azole drug fluconazole, used in the treatment of diseases caused by some species of Tremellomycetes, inhibits cytochrome P450 monooxygenase CYP51, an enzyme that converts lanosterol into an essential component of the fungal cell membrane ergosterol. Studies indicate that mutations and over-expression of CYP51 in species of Tremellomycetes are one of the reasons for fluconazole resistance. Moreover, the novel drug, VT-1129, that is in the pipeline is reported to exert its effect by binding and inhibiting CYP51. Despite the importance of CYPs, the CYP repertoire in species of Tremellomycetes has not been reported to date. This study intends to address this research gap. Comprehensive genome-wide CYP analysis revealed the presence of 203 CYPs (excluding 16 pseudo-CYPs) in 23 species of Tremellomycetes that can be grouped into 38 CYP families and 72 CYP subfamilies. Twenty-three CYP families are new and three CYP families (CYP5139, CYP51 and CYP61) were conserved across 23 species of Tremellomycetes. Pathogenic cryptococcal species have 50% fewer CYP genes than non-pathogenic species. The results of this study will serve as reference for future annotation and characterization of CYPs in species of Tremellomycetes.


Assuntos
Basidiomycota/genética , Família 51 do Citocromo P450/genética , Proteínas Fúngicas/genética , Variação Genética , Basidiomycota/classificação , Basidiomycota/enzimologia , Filogenia
17.
J Basic Microbiol ; 59(7): 667-679, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-31087565

RESUMO

A psychrotolerant yeast strain Mrakia robertii A2-3 isolated from cryoconites of Hamtah glacier, Himalaya, India was investigated for the production of cold-tolerant endoglucanase. Optimum endoglucanase production was found at 15°C with an initial pH of 5.5, and potent inducers were 1% wt/vol of xylose and KNO3 and 0.1% wt/vol of NaCl. Under optimum conditions, the enzyme production was 1.81-fold higher than the unoptimized conditions. Crude enzyme was partially purified by ammonium sulfate precipitation followed by dialysis. The enzyme was purified to 2.53-fold and the yield was 6.03% with specific activity of 17.38 U/mg and molecular weight ~57 kDa. The Km and Vmax values of the partially purified enzyme were found to be 1.57 mg/ml and 142.85 U/mg, respectively. The characterization study revealed that the best temperature was 15°C for activity and stability. Furthermore, the enzyme showed the highest activity at pH 11.0 and was stable at pH 6.0. Fe2+ , Mn2+ , Na2+ , Cu2+ , Co2+ , Ca2+ proved to be activators of endoglucanase. Ethylenediamine tetraacetic acid showed very low effect on the enzyme activity whereas it was active with Tween-80 and sodium deoxycholate. The present study successfully produced a cold-active endoglucanase with novel properties making it promising as a biocatalyst for industrial processes.


Assuntos
Basidiomycota/enzimologia , Celulase/fisiologia , Temperatura Baixa , Camada de Gelo/microbiologia , Basidiomycota/classificação , Basidiomycota/fisiologia , Carboximetilcelulose Sódica/metabolismo , Celulase/química , Celulase/isolamento & purificação , Celulase/metabolismo , DNA Fúngico/genética , DNA Ribossômico/genética , Detergentes , Ativadores de Enzimas , Estabilidade Enzimática , Concentração de Íons de Hidrogênio , Índia , Cinética , Peso Molecular , Filogenia , Análise de Sequência de DNA
18.
Int J Syst Evol Microbiol ; 69(8): 2367-2371, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31145674

RESUMO

Two conspecific yeast strains, which based on DNA sequence comparisons represented an undescribed species in the order Trichosporonales were isolated during two independent studies in Hungary and France. One of them (NCAIM Y.02224) was recovered from minced pork in Hungary while the other one (UBOCC-A-218003) was isolated from the air of a dairy plant in France. The two strains shared identical nucleotide sequences in the D1/D2 domain of the nuclear large subunit (LSU) rRNA gene and in the internal transcribed spacer (ITS) region. Analysis of the concatenated DNA sequences for the ITS region and D1/D2 domain of the LSU rRNA gene indicated that the novel species belongs to the recently erected genus Cutaneotrichosporon. According to sequence comparisons and phylogenetic analysis, the novel species is most closely related to Cutaneotrichosporon curvatum (formerly Cryptococcus curvatus), which is often associated with humans and warm-blooded animals. The physiological characteristics of this novel species are also very similar to that of Cutaneotrichosporon curvatum. The only clear-cut difference is that, unlike C. curvatum, the novel species does not utilize imidazole as a nitrogen-source. The species name Cutaneotrichosporon suis sp. nov. is proposed to accommodate the above-noted two strains.


Assuntos
Basidiomycota/classificação , Microbiologia de Alimentos , Filogenia , Basidiomycota/isolamento & purificação , DNA Fúngico/genética , DNA Espaçador Ribossômico/genética , Indústria de Laticínios , França , Hungria , Carne/microbiologia , Técnicas de Tipagem Micológica , Análise de Sequência de DNA
19.
Int J Syst Evol Microbiol ; 69(7): 2010-2016, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-31063122

RESUMO

Ten strains representing a single anamorphic novel yeast species were isolated from the external surface (DMKU-SP23 and DMKU-SP40) and tissue (DMKU-SE89, DMKU-SE99, DMKU-SE100 and DMKU-SE147) of sugarcane leaves in Thailand, and phylloplane (IMUFRJR 52034) and rhizoplane (IMUFRJ 52036 and 52037) of sugarcane and associated soil (IMUFRJ 52035) in Brazil. These strains showed zero to two nucleotide substitutions in the sequences of the D1/D2 region of the LSU rRNA gene and zero to three nucleotide substitutions in the internal transcribed spacer (ITS) region. Tremella globispora was the most closely related species, but with 1.7-2.1 % nucleotide substitutions in the D1/D2 region of the LSU rRNA gene, and 5.3-6.0 % nucleotide substitutions in the ITS region. Phylogenetic analysis based on the concatenated sequences of the ITS and the D1/D2 regions showed that these 10 strains represented a single species belonging to the genus Tremella (class Tremellomycetes, subphylum Agaricomycotina) that was distinct from related species. They therefore represented a novel species of the genus Tremella although the formation of basidia and basidiocarp were not observed. The name Tremella saccharicola f.a., sp. nov. is proposed. The type strain is DMKU-SP23T (=NBRC 109698T=BCC 61186T).


Assuntos
Basidiomycota/classificação , Filogenia , Saccharum/microbiologia , Microbiologia do Solo , Basidiomycota/isolamento & purificação , Brasil , DNA Fúngico/genética , DNA Espaçador Ribossômico/genética , Técnicas de Tipagem Micológica , Folhas de Planta/microbiologia , Rizosfera , Análise de Sequência de DNA , Tailândia
20.
Microb Ecol ; 78(3): 565-574, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-30895363

RESUMO

In field and laboratory experiments during 2014-2017, we investigated the influence of lower and higher cultivation intensity of wheat and ecological factors (weather-temperature and rainfalls, year) on the occurrence of phytopathogenic fungi on the leaves of winter wheat. The prevailing fungi in those years were Mycosphaerella graminicola (Fuckel) J. Schrott and Pyrenophora tritici-repentis (Died.) Drechsler. Using cluster analysis, we statistically evaluated interrelationships of known factors on the abundance of the fungi on leaf surfaces. Our results showed strongest correlation with Mycosphaerella graminicola and Pyrenophora tritici-repentis abundance to be with lower cultivation intensity and year done by the temperature and the rainfalls. The two pathogens-Puccinia tritici Oerst and Hymenula cerealis Ellis & Everh. occurred only very sparsely in some years and had little positive or negative correlation with named factors. The semi-early and semi-late winter wheat varieties Matchball, Annie, Fakir, and Tobak were used for our experiments. Higher cultivation intensity had protective effect against leaf phytopathogenic fungi.


Assuntos
Ascomicetos/isolamento & purificação , Basidiomycota/isolamento & purificação , Doenças das Plantas/microbiologia , Triticum/microbiologia , Ascomicetos/classificação , Ascomicetos/genética , Ascomicetos/crescimento & desenvolvimento , Basidiomycota/classificação , Basidiomycota/genética , Basidiomycota/crescimento & desenvolvimento , Ecossistema , Temperatura Ambiente
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA