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1.
Sci Rep ; 13(1): 11819, 2023 07 21.
Artigo em Inglês | MEDLINE | ID: mdl-37479715

RESUMO

Four yeast strains were isolated from the gut of stingless bee, collected in Churdhar, Himachal Pradesh, India. Physiological characterization, morphological examination, and sequence analysis of small subunit ribosomal RNA (18S rRNA) genes, internal transcribed spacer (ITS) region, and D1/D2 domain of the large subunit rRNA gene revealed that the four strains isolated from the gut of stingless bee belonged to the Debaryomyces clade. Strain CIG-23HT showed sequence divergence of 7.5% from Debaryomyces nepalensis JCM 2095T, 7.8% from Debaryomyces udenii JCM 7855T, and Debaryomyces coudertii JCM 2387T in the D1/D2 domain. In the ITS region sequences, strain CIG-23HT showed a 15% sequence divergence from Debaryomyces nepalensis JCM 2095T and Debaryomyces coudertii JCM 2387T. In 18S rRNA gene sequence, the strain CIG-23HT showed 1.14% sequence divergence from Debaryomyces nepalensis JCM 2095 and and Debaryomyces coudertii JCM 2387, and 0.83% sequence divergence from Debaryomyces hansenii NRRL Y-7426. Strain CIG-23HT can utilize more carbon sources than closely related species. The findings suggest that strain CIG-23HT is a novel species of the genus Debaryomyces, and we propose to name it as Debaryomyces apis f.a., sp. nov. The holotype is CBS 16297T, and the isotypes are MTCC 12914T and KCTC 37024T. The MycoBank number of Debaryomyces apis f.a., sp. nov. is MB836065. Additionally, a method using cresol red and Bromothymol blue pH indicator dyes was developed to screen for lipase producers, which is more sensitive and efficient than the currently used phenol red and rhodamine B dye-based screening methods, and avoids the problem of less differentiable zone of hydrolysis.


Assuntos
Debaryomyces , Abelhas/genética , Animais , Debaryomyces/genética , Corantes , Filogenia , Lipase/genética , RNA Ribossômico/genética , Concentração de Íons de Hidrogênio , Análise de Sequência de DNA , DNA Fúngico/genética , DNA Fúngico/química , Técnicas de Tipagem Micológica , DNA Espaçador Ribossômico/genética , DNA Espaçador Ribossômico/química
2.
FEMS Yeast Res ; 19(1)2019 01 01.
Artigo em Inglês | MEDLINE | ID: mdl-30202936

RESUMO

This work reports important results of aromatic profiles produced by native yeasts isolated from desert-grown wine grapes from the south of Chihuahua, México. These grapes stand very high temperatures during the ripening season, developing high sugar concentration and high pH. Yeast species found in grapes were identified by polymerase chain reaction and sequence analysis of the 5.8S internal transcribed spacer ribosomal RNA region. Aureobasidium namibiae, Sporobolomyces johnsonii, Candida apicola, Hanseniaspora uvarum, Candida thaimueangensis, Hanseniaspora opuntiae were identified. All of them can grow at glucose concentration of 35% (w/v) and 100 ppm of SO2, and produce low volatile acidity (0.2-1.0 g acetic acid/L). Volatile organic compounds analysis showed that C. thaimueangensis and one strain of C. apicola produce high levels of esters, and Hanseniaspora species produces high levels of higher alcohols and carbonyl compounds. The results of this study contribute to the knowledge about yeast communities associated with desert-grown winegrape yeasts.


Assuntos
Fermentação , Vitis/microbiologia , Leveduras/classificação , Leveduras/metabolismo , Análise por Conglomerados , DNA Fúngico/química , DNA Fúngico/genética , DNA Ribossômico/química , DNA Ribossômico/genética , DNA Espaçador Ribossômico/química , DNA Espaçador Ribossômico/genética , Glucose/metabolismo , México , Filogenia , RNA Ribossômico 5,8S/genética , Análise de Sequência de DNA , Compostos Orgânicos Voláteis/metabolismo , Leveduras/genética , Leveduras/isolamento & purificação
3.
Fungal Biol ; 122(5): 283-292, 2018 05.
Artigo em Inglês | MEDLINE | ID: mdl-29665954

RESUMO

The increase of infections due to non-Candida albicans species made it very necessary to conduct adequate characterization to be able to identify the species of Candida isolated from traditional fermented foods. In this study, based on their hue on Candida Chromogenic Agar medium, a total of 136 yeast strains were isolated from tchapalo and bangui. Molecular identification based on PCR-RFLP of internal transcribed spacers of rDNA (ITS) and sequencing of the ITS and the D1/D2 regions allowed us to assign these isolates to seven species: Candida tropicalis, Candida inconspicua, Candida rugosa, Saccharomyces cerevisiae, Kluyveromyces marxianus, Hanseniaspora guilliermondii, Trichosporon asahii. With the respect to each beverage, six species were found among with four species are regarded as opportunistic pathogens. From these, C. tropicalis, C. inconspicua and K. marxianus were the most commonly encountered. The enzyme activities of the potential pathogens assessed using API ZYM system showed that almost strains had esterase, esterase lipase, valine and cystine arylamidase, alpha chymotrypsin, alkaline phosphatase and naphthol phosphohydrolase activities. The activity of α-glucosidase was found only in C. tropicalis and C. inconspicua strains isolated from tchapalo while ß-glucosidase activity was found in all strains from tchapalo and only in C. inconspicua isolated from bangui.


Assuntos
Bebidas Alcoólicas/microbiologia , Saccharomycetales/classificação , Saccharomycetales/isolamento & purificação , Análise por Conglomerados , Côte d'Ivoire , DNA Fúngico/química , DNA Fúngico/genética , DNA Ribossômico/química , DNA Ribossômico/genética , DNA Espaçador Ribossômico/química , DNA Espaçador Ribossômico/genética , Enzimas/análise , Filogenia , Reação em Cadeia da Polimerase , Polimorfismo de Fragmento de Restrição , RNA Ribossômico/genética , Saccharomycetales/enzimologia , Saccharomycetales/genética , Análise de Sequência de DNA , Trichosporon/classificação , Trichosporon/genética , Trichosporon/isolamento & purificação
4.
J Microbiol Biotechnol ; 28(1): 105-108, 2018 Jan 28.
Artigo em Inglês | MEDLINE | ID: mdl-29081086

RESUMO

Beef was dry aged for 40-60 days under controlled environmental conditions in a refrigerated room with a relative humidity of 75%-80% and air-flow. To date, there is little information on the microbial diversity and characteristics of dry aged beef. In this study, we explored the effect of change in meat microorganisms on dry aged beef. Initially, the total bacteria and LAB were significantly increased for 50 days during all dry aging periods. There was an absence of representative foodborne pathogens as well as coliforms. Interestingly, fungi including yeast and mold that possess specific features were observed during the dry aging period. The 5.8S rRNA sequencing results showed that potentially harmful yeasts/molds (Candida sp., Cladosporium sp., Rhodotorula sp.) were present at the initial point of dry aging and they disappeared with increasing dry aging time. Interestingly, Penicillium camemberti and Debaryomyces hansenii used for cheese manufacturing were observed with an increase in the dry aging period. Taken together, our results showed that the change in microorganisms exerts an influence on the quality and safety of dry aged beef, and our study identified that fungi may play an important role in the palatability and flavor development of dry aged beef.


Assuntos
Bactérias/isolamento & purificação , Biota , Dessecação , Fungos/isolamento & purificação , Carne/microbiologia , Técnicas Microbiológicas/métodos , Animais , Bactérias/classificação , Bovinos , Análise por Conglomerados , DNA Fúngico/química , DNA Fúngico/genética , DNA Ribossômico/química , DNA Ribossômico/genética , Fungos/classificação , Fungos/genética , Filogenia , RNA Ribossômico 5,8S/genética , Análise de Sequência de DNA
5.
Microbiology (Reading) ; 161(10): 2008-2018, 2015 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-26253443

RESUMO

Fructophily has been described in yeasts as the ability to utilize fructose preferentially when fructose and glucose are available in the environment. In Zygosaccharomyces bailii and Zygosaccharomyces rouxii, fructophilic behaviour has been associated with the presence of a particular type of high-capacity and low-affinity fructose transporters designated Ffz. In this study, a PCR screening was performed in several yeasts using degenerate primers suitable to detect FFZ-like genes. In parallel, fructophilic character was evaluated in the same strains by comparing the relative consumption rate of fructose and glucose. For all the strains in which FFZ-like genes were detected, fructophilic behaviour was observed (25 strains). Results show that FFZ genes are ubiquitous in the Zygosaccharomyces and Starmerella clades. Strains of Lachancea fermentati, Torulaspora microellipsoides and Zygotorulaspora florentina were not fructophilic and did not harbour FFZ genes. It is of note that these new species were recently removed by taxonomists from the Zygosaccharomyces clade, supporting the view that the presence of FFZ-like genes is a main characteristic of Zygosaccharomyces. Among the strains tested, only Hanseniaspora guilliermondii NCYC2380 was an exception, having a preference for fructose in medium with high sugar concentrations, despite no FFZ-like genes being detected in the screening. Furthermore, this study supports the previous idea of the emergence of a new family of hexose transporters (Ffz facilitators) distinct from the Sugar Porter family.


Assuntos
Frutose/metabolismo , Proteínas de Transporte de Monossacarídeos/genética , Proteínas de Transporte de Monossacarídeos/metabolismo , Saccharomycetales/genética , Saccharomycetales/metabolismo , DNA Fúngico/química , DNA Fúngico/genética , Testes Genéticos , Glucose/metabolismo , Dados de Sequência Molecular , Reação em Cadeia da Polimerase , Análise de Sequência de DNA
6.
Antonie Van Leeuwenhoek ; 108(3): 633-47, 2015 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-26122889

RESUMO

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.


Assuntos
Endófitos/classificação , Variação Genética , Oryza/microbiologia , Folhas de Planta/microbiologia , Leveduras/classificação , Análise por Conglomerados , DNA Fúngico/química , DNA Fúngico/genética , DNA Ribossômico/química , DNA Ribossômico/genética , Endófitos/genética , Genes de RNAr , Dados de Sequência Molecular , Filogenia , RNA Fúngico/genética , RNA Ribossômico/genética , Análise de Sequência de DNA , Leveduras/genética
7.
Curr Microbiol ; 70(6): 792-800, 2015 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-25694357

RESUMO

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.


Assuntos
Biodiversidade , Queijo/microbiologia , Fungos/classificação , Fungos/isolamento & purificação , Análise por Conglomerados , DNA Fúngico/química , DNA Fúngico/genética , DNA Espaçador Ribossômico/química , DNA Espaçador Ribossômico/genética , Fungos/genética , Fungos/fisiologia , Técnicas Microbiológicas , Dados de Sequência Molecular , Filogenia , Análise de Sequência de DNA
8.
Antonie Van Leeuwenhoek ; 107(2): 487-501, 2015 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-25480727

RESUMO

Ice from Arctic glaciers contains large populations of yeasts. We studied 38 isolates from this environment, which were initially identified as Debaryomyces sp. related to Debaryomyces hansenii by sequence analysis of the D1/D2 domains of 26S rDNA. An analysis of the distribution of mitochondrial DNA insertions in the nuclear genome showed that 25 of these isolates were related to, but distinct from, D. hansenii. Sequence analysis of the ACT1 gene of these 25 isolates revealed that they formed three different types of putative hybrids. In particular, 23 putative hybrids carried an ACT1 sequence identical to that of three Debaryomyces strains, CBS 790, CLIB 660, CLIB 949, previously classified as associated with D. hansenii and an ACT1 sequence of an undescribed taxon. The latter sequence displayed between 22 and 27 bp divergence (2.6-3.2 %) over 841 bp from sequences of closely related Debaryomyces sp., suggesting that this new taxon very likely represents a novel species for which no pure strain is available. Sequence comparisons of CBS 790, CLIB 660, and CLIB 949 with related Debaryomyces type strains also revealed an important sequence divergence. The putative hybrids described in this study could be differentiated from non-hybrid isolates and other Debaryomyces species on the basis of their use of a number of carbon sources.


Assuntos
Variação Genética , Camada de Gelo/microbiologia , Saccharomycetales/classificação , Saccharomycetales/genética , Actinas/genética , Regiões Árticas , Análise por Conglomerados , DNA Fúngico/química , DNA Fúngico/genética , DNA Ribossômico/química , DNA Ribossômico/genética , Dados de Sequência Molecular , Filogenia , RNA Ribossômico/genética , Recombinação Genética , Saccharomycetales/isolamento & purificação , Análise de Sequência de DNA
9.
Mycologia ; 106(6): 1073-89, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-25143478

RESUMO

Seven acidophilic/acidotolerant fungal strains were characterized from samples of process waters (raffinate) at one of Australia's largest uranium mines, the Ranger Mine in Northern Territory. They were isolated from raffinate, which typically were very acidic (pH 1.7-1.8) and contained high concentrations of total dissolved/colloidal salts (> 100 g/L). Five of the isolates correspond to two new acidotolerant Ascomycota fungi. The first is a member of a new genus, here described as Fodinomyces (Teratosphaeriaceae, Capnodiales, Dothideomycetes) and does not show clear close affiliation with any other described fungus in the scientific literature. The second belongs to the genus Coniochaeta (Coniochaetaceae, Coniochaetales, Sordariomycetes) and is closely related to Coniochaeta hansenii.


Assuntos
Ascomicetos/classificação , Ascomicetos/citologia , Ascomicetos/genética , Ascomicetos/isolamento & purificação , Austrália , Sequência de Bases , DNA Fúngico/química , DNA Fúngico/genética , DNA Ribossômico/química , DNA Ribossômico/genética , DNA Espaçador Ribossômico/química , DNA Espaçador Ribossômico/genética , Mineração , Dados de Sequência Molecular , Micélio , Filogenia , Análise de Sequência de DNA , Esporos Fúngicos , Urânio , Microbiologia da Água
10.
Braz J Microbiol ; 45(1): 135-42, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-24948924

RESUMO

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.


Assuntos
Biodiversidade , Lagos/microbiologia , Leveduras/classificação , Leveduras/isolamento & purificação , Colômbia , DNA Fúngico/química , DNA Fúngico/genética , DNA Ribossômico/química , DNA Ribossômico/genética , Sedimentos Geológicos/microbiologia , Dados de Sequência Molecular , Reação em Cadeia da Polimerase , RNA Ribossômico/genética , Análise de Sequência de DNA , Microbiologia da Água , Leveduras/genética
11.
Braz. j. microbiol ; 45(1): 135-142, 2014. ilus, tab
Artigo em Inglês | LILACS | ID: lil-709467

RESUMO

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.


Assuntos
Biodiversidade , Lagos/microbiologia , Leveduras/classificação , Leveduras/isolamento & purificação , Colômbia , DNA Fúngico/química , DNA Fúngico/genética , DNA Ribossômico/química , DNA Ribossômico/genética , Sedimentos Geológicos/microbiologia , Dados de Sequência Molecular , Reação em Cadeia da Polimerase , RNA Ribossômico/genética , Análise de Sequência de DNA , Microbiologia da Água , Leveduras/genética
12.
J Gen Appl Microbiol ; 59(1): 49-58, 2013.
Artigo em Inglês | MEDLINE | ID: mdl-23518518

RESUMO

A polyphasic molecular approach was used in order to characterize and taxonomically assign Debaryomyces yeast isolates of different origins. Actin 1 (ACT1) gene sequences coupled with AFLP markers showed that the investigated yeasts belonged to the recently reinstated species D. hansenii, D. fabryi and D. tyrocola. The strain HA1179 was supposed to be a D. hansenii strain with introgressed D. fabryi DNA segments. This strain acquired ribosomal RNA encoding genes (rDNA) and the ACT1 gene from the species D. fabryi and D. hansenii respectively. Comparative sequence analysis of the ACT1 gene, ITS1-5.8S-ITS2 (5.8S-ITSs) and D1/D2 regions, suggested that five strains isolated from a municipal wastewater treatment plant could represent a new taxon of the genus, for which the name Debaryomyces vindobonensis was proposed. The calculated degree of similarity between the AFLP patterns indicated that the strains of D. vindobonensis and the closely related species were separated by the values <0.5. New yeast isolates showed very similar morphological and physiological properties to related Debaryomyces species. They differed notably only by the assimilation of rhamnose and growth at 50% glucose. In contrast to the other species, D. vindobonensis was unable to assimilate starch.


Assuntos
Saccharomycetales/classificação , Saccharomycetales/isolamento & purificação , Águas Residuárias/microbiologia , Actinas/genética , Análise do Polimorfismo de Comprimento de Fragmentos Amplificados , Análise por Conglomerados , DNA Fúngico/química , DNA Fúngico/genética , DNA Ribossômico/química , DNA Ribossômico/genética , DNA Espaçador Ribossômico/química , DNA Espaçador Ribossômico/genética , Dados de Sequência Molecular , Filogenia , Saccharomycetales/genética , Análise de Sequência de DNA
13.
Med Mycol ; 50(1): 106-9, 2012 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-21838615

RESUMO

We report the diagnosis and molecular characterization of lobomycosis-like lesions in a captive bottlenose dolphin. The clinical picture and the absence of growth in conventional media resembled the features associated with Lacazia loboi. However sequencing of ribosomal DNA and further phylogenetic analyses showed a novel sequence more related to Paracoccidioides brasilensis than to L. loboi. Moreover, the morphology of the yeast cells differed from those L. loboi causing infections humans. These facts suggest that the dolphin lobomycosis-like lesions might have been be caused by different a different fungus clustered inside the order Onygenales. A successful treatment protocol based on topic and systemic terbinafine is also detailed.


Assuntos
Animais de Zoológico , Golfinho Nariz-de-Garrafa , Paracoccidioides/isolamento & purificação , Paracoccidioidomicose/veterinária , Animais , DNA Fúngico/química , DNA Fúngico/genética , Lobomicose/patologia , Lobomicose/veterinária , Dados de Sequência Molecular , Paracoccidioides/citologia , Paracoccidioides/genética , Paracoccidioidomicose/diagnóstico , Paracoccidioidomicose/microbiologia , Paracoccidioidomicose/patologia , Análise de Sequência de DNA
14.
Mycoses ; 54(6): e811-5, 2011 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-21672044

RESUMO

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.


Assuntos
Biodiversidade , Aves/microbiologia , Fezes/microbiologia , Leveduras/classificação , Leveduras/isolamento & purificação , Animais , Regiões Antárticas , DNA Fúngico/química , DNA Fúngico/genética , DNA Espaçador Ribossômico/química , DNA Espaçador Ribossômico/genética , Ilhas Malvinas , Tipagem Molecular , Técnicas de Tipagem Micológica , Análise de Sequência de DNA
15.
FEMS Yeast Res ; 9(8): 1327-37, 2009 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-19788563

RESUMO

In the course of a survey of yeast biodiversity in the natural substrates in Thailand, eight strains were found to represent three hitherto undescribed species of Hanseniaspora/Kloeckera. They were isolated from insect frass, flower, lichen, rotted fruit and rotted wood. Based on the morphological and physiological characteristics, and sequences of D1/D2 domain, six strains represent a single species of the genus Hanseniaspora, described as Hanseniaspora thailandica sp. nov. (type BCC 14938(T)=NBRC 104216(T)=CBS 10841(T)), and another strain as Hanseniaspora singularis sp. nov. (type BCC 15001(T)=NBRC 104214(T)=CBS 10840(T)). A further strain, which belongs to Kloeckera and does not produce ascospores, is described as Kloeckera hatyaiensis sp. nov. (type BCC 14939(T)=NBRC 104215(T)=CBS 10842(T)). Strains belonging to H. thailandica sp. nov. differed by 17-19 nucleotide substitutions from Hanseniaspora meyeri, the closest species. DNA reassociation between the two taxa showed 30-48% relatedness. Kloeckera hatyaiensis sp. nov. and H. singularis sp. nov. differed by eight and 16 nucleotide substitutions with one gap from the nearest species, Hanseniaspora clermontiae and Hanseniaspora valbyensis, respectively.


Assuntos
Hanseniaspora/classificação , Hanseniaspora/isolamento & purificação , Insetos/microbiologia , Kloeckera/classificação , Kloeckera/isolamento & purificação , Plantas/microbiologia , Animais , Composição de Bases , Análise por Conglomerados , DNA Fúngico/química , DNA Fúngico/genética , DNA Ribossômico/química , DNA Ribossômico/genética , Genes de RNAr , Hanseniaspora/genética , Hanseniaspora/fisiologia , Kloeckera/genética , Kloeckera/fisiologia , Dados de Sequência Molecular , Técnicas de Tipagem Micológica , Hibridização de Ácido Nucleico , Filogenia , RNA Fúngico/genética , RNA Ribossômico 28S/genética , Análise de Sequência de DNA , Esporos Fúngicos/citologia , Tailândia , Ubiquinona/análise
16.
Mycologia ; 100(3): 397-416, 2008.
Artigo em Inglês | MEDLINE | ID: mdl-18751548

RESUMO

This investigation elucidates relationships within the Lecania cyrtella group (Ramalinaceae, lichenized Ascomycota) by employing morphological, anatomical and molecular methods. The morphological studies included eleven species of Lecania, L. cyrtella, L. cyrtellina, L. dubitans, L. erysibe, L. hutchinsiae, L. leprosa, L. madida, L. prasinoides, L. sambucina, L. sordida and L. sylvestris, and a key to the species plus species descriptions are provided. Lecania madida, a new species from the Pacific Northwest of North America, L. leprosa, a new species from eastern Europe, and L. sordida, a new species from Europe, are described here. The known range of L. prasinoides is greatly extended to include the Baltic countries, Nordic countries and western Canada. Lectotypes are designated for L. cyrtella and L. sambucina. Molecular relationships within the group were examined with haplotype network estimations and phylogenetic reconstructions. Part of the IGS region as well as the complete ITS region were sequenced and analyzed. Both the haplotype network and the phylogenetic analyses indicate that the included species, as conceived in the morphological examinations, all are monophyletic.


Assuntos
Ascomicetos/classificação , Ascomicetos/citologia , Ascomicetos/genética , DNA Fúngico/química , DNA Fúngico/genética , DNA Ribossômico/química , DNA Ribossômico/genética , DNA Espaçador Ribossômico/química , DNA Espaçador Ribossômico/genética , Europa (Continente) , Haplótipos , Dados de Sequência Molecular , América do Norte , Filogenia , Análise de Sequência de DNA , Esporos Fúngicos/citologia
17.
Int J Food Microbiol ; 126(1-2): 195-201, 2008 Aug 15.
Artigo em Inglês | MEDLINE | ID: mdl-18597878

RESUMO

Small cell numbers in complex food matrices and undefined PCR inhibitors often limit detection and identification of DNA species by molecular techniques. Thus in many industrial situations enrichment growths are performed. However, growth speed of different species in complex microbial mixtures in defined media is in most cases different, thus final results do not always reflect the starting situation. We tested DNA-strand displacement whole genome amplification as a possible substitute of enrichment growth. Using whole genome amplification on orange juice contaminated with Saccharomyces cerevisiae, we lowered detection level from 10(6) down to 10(2) cfu/ml. Whole genome amplification showed to be linear (R=0.992) and the relative yeast DNA copy number compared to other DNA templates did not change thus allowing quantitative estimation of initial contamination by quantitative PCR. Using melting point analysis, we were able to distinguish between the PCR products of the 5.8S-ITS region, obtained with universal primers from pure cultures of S. cerevisiae and Hanseniaspora uvarum, two major spoilage yeasts in orange juice and forming part of wine microbiota during fermentation. However, in mixed-contaminated samples, identification of both species was hampered by preferential appearance of the melting peak coinciding with H. uvarum, except when S. cerevisiae was the dominating species. Application of whole genome amplification did not prevent the preferential detection of H. uvarum. This handicap was resolved by applying an enrichment procedure up to saturation after which the melting peak of both species could clearly be identified.


Assuntos
Bebidas/microbiologia , Contaminação de Alimentos/análise , Hanseniaspora/isolamento & purificação , Reação em Cadeia da Polimerase/métodos , Saccharomyces cerevisiae/isolamento & purificação , Citrus sinensis/microbiologia , Contagem de Colônia Microbiana/métodos , DNA Fúngico/química , DNA Fúngico/genética , Amplificação de Genes , Genoma Fúngico/genética , RNA Ribossômico 5,8S/química , RNA Ribossômico 5,8S/genética , Sensibilidade e Especificidade , Especificidade da Espécie
18.
Int J Food Microbiol ; 125(2): 197-203, 2008 Jul 15.
Artigo em Inglês | MEDLINE | ID: mdl-18495281

RESUMO

This detailed study observed the yeasts present in the ecological niche of "wine must". The dynamics and identity of non-Saccharomyces yeasts during the cold maceration and alcoholic fermentation of grape must were investigated under real production conditions in the Bordeaux region. Furthermore, we studied the impact of two oenological parameters on the development and diversity of non-Saccharomyces yeasts during cold maceration: temperature management and the timing of dried yeast addition. The non-Saccharomyces community underwent constant changes throughout cold maceration and alcoholic fermentation. The highly diverse non-Saccharomyces microflora was present at 10(4)-10(5) CFU/mL during cold maceration. The population increased to a maximum of 10(6)-10(7) CFU/mL at the beginning of alcoholic fermentation, then declined again at the end. The population at this point, evaluated at around 10(3)-10(4) CFU/mL, was shown to be dependent on the timing of yeast inoculation. The choice of temperature was the key factor for controlling the total yeast population growth, as well as the species present at the end of cold maceration. Hanseniaspora uvarum was a major species present in 2005 and 2006, while Candida zemplinina was very abundant in 2006. A total of 19 species were isolated.


Assuntos
Manipulação de Alimentos/métodos , Microbiologia Industrial , Polimorfismo de Fragmento de Restrição , Vinho/microbiologia , Leveduras/classificação , Leveduras/crescimento & desenvolvimento , Contagem de Colônia Microbiana , DNA Fúngico/química , DNA Fúngico/genética , Etanol/metabolismo , Fermentação , Cinética , Reação em Cadeia da Polimerase/métodos , Dinâmica Populacional , Crescimento Demográfico , Especificidade da Espécie , Temperatura , Fatores de Tempo , Leveduras/genética , Leveduras/isolamento & purificação
19.
Curr Microbiol ; 56(4): 358-62, 2008 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-18183460

RESUMO

Fungal communities in decaying sapwood and heartwood of K. evelyniana were demonstrated through construction of four 18 S rRNA gene libraries. The 210 sequenced clones were clustered into 11 subgroups, belonging to Basidiomycota (71.9%) and to Ascomycota (22.4%) and unclassified (1 subgroup; 5.7%). The heartwood displayed higher species richness than the sapwood. Basidiomycota were dominant in either the heartwood or the sapwood. Phylogenetically diverse Homobasidiomycetes were detected in the heartwood, contrary to the sapwood, where Heterobasidiomycetes were detected. Clones close to Spongipellis unicolor dominated in the heartwood (21 of 99 clones), while those close to Hydnochaete olivacea dominated in the sapwood (41 of 111 clones). The common species between the two parts were those related to S. unicolor, Calocera cornea, Debaryomyces hansenii, Davidiella tassiana, and Nomuraea rileyi and those from Chaetothyriomycetes.


Assuntos
Biodiversidade , Fungos/classificação , Fungos/isolamento & purificação , Pinaceae/microbiologia , Madeira/microbiologia , Análise por Conglomerados , DNA Fúngico/química , DNA Fúngico/genética , DNA Ribossômico/química , DNA Ribossômico/genética , Dados de Sequência Molecular , Filogenia , RNA Ribossômico 18S/genética , Análise de Sequência de DNA , Homologia de Sequência do Ácido Nucleico
20.
Syst Appl Microbiol ; 30(7): 547-60, 2007 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-17604934

RESUMO

The microbial communities in milks from one herd were evaluated during 1-year of lactation, using molecular methods to evaluate their stability and the effect of breeding conditions on their composition. The diversity of microbial communities was measured using two approaches: molecular identification by 16S and 18S rDNA sequencing of isolates from counting media (two milks), and direct identification using 16S rDNA from clone libraries (six milks). The stability of these communities was evaluated by counting on selective media and by Single Strand Conformation Polymorphism (SSCP) analysis of variable region V3 of the 16S rRNA gene and variable region V4 of the 18S rRNA gene. One hundred and eighteen milk samples taken throughout the year were analyzed. Wide diversity among bacteria and yeasts in the milk was revealed. In addition to species commonly encountered in milk, such as Lactococcus lactis, Lactococcus garvieae, Enterococcus faecalis, Lactobacillus casei, Leuconostoc mesenteroides, Staphylococcus epidermidis, Staphylococcus simulans, Staphylococcus caprae, Staphylococcus equorum, Micrococcus sp., Kocuria sp., Pantoea agglomerans and Pseudomonas putida, sequences were affiliated to other species only described in cheeses, such as Corynebacterium variabile, Arthrobacter sp., Brachybacterium paraconglomeratum, Clostridium sp. and Rothia sp. Several halophilic species atypical in milk were found, belonging to Jeotgalicoccus psychrophilus, Salinicoccus sp., Dietza maris, Exiguobacterium, Ornithinicoccus sp. and Hahella chejuensis. The yeast community was composed of Debaryomyces hansenii, Kluyveromyces lactis, Trichosporon beigelii, Rhodotorula glutinis, Rhodotorula minuta, Candida pararugosa, Candida intermedia, Candida inconspicua, Cryptococcus curvatus and Cryptococcus magnus. The analyses of microbial counts and microbial SSCP profiles both distinguished four groups of milks corresponding to four periods defined by season and feeding regime. The microbial community was stable within each period. Milks from winter were characterized by Lactococcus and Pseudomonas, those from summer by P. agglomerans and Klebsiella and those from autumn by Chryseobacterium indologenes, Acinetobacter baumanii, Staphylococcus, Corynebacteria and yeasts. However, the composition of the community can vary according to factors other than feeding. This study opens new investigation fields in the field of raw milk microbial ecology.


Assuntos
Bactérias/classificação , Biodiversidade , Fungos/classificação , Leite/microbiologia , Animais , Bactérias/isolamento & purificação , Contagem de Colônia Microbiana , DNA Bacteriano/química , DNA Bacteriano/genética , DNA Fúngico/química , DNA Fúngico/genética , DNA Ribossômico/química , DNA Ribossômico/genética , Métodos de Alimentação , Fungos/isolamento & purificação , Cabras , Lactação , Dados de Sequência Molecular , Filogenia , Polimorfismo Conformacional de Fita Simples , RNA Ribossômico 16S/genética , RNA Ribossômico 18S/genética , Estações do Ano , Análise de Sequência de DNA
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