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1.
Int J Syst Evol Microbiol ; 74(10)2024 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-39352401

RESUMO

Two strains, designated JCM 36746T and JCM 36749, were isolated from Bengal clock vine (Thunbergia grandiflora) and soil, respectively, in Okinawa, Japan. Analysis of the internal transcribed spacer (ITS) regions and D1/D2 domains of the large subunit rRNA gene sequences revealed identical sequences in both strains, indicating that they belong to the same species. Sequence analysis and physiological characterization identified these strains as representing a novel yeast species in the genus Yamadazyma. The sequence similarities of the concatenated ITS regions and D1/D2 domains indicated that JCM 36746T and JCM 36749 formed a well-supported distinct from closely related species belonging to the Yamadazyma clade, including Candida dendronema, C. diddensiae, C. germanica, C. kanchanaburiensis, C. naeodendra, C. vaughaniae, Y. akitaensis, Y. koratensis, Y. nakazawae, Y. philogaea, Y. phyllophila, Y. siamensis, Y. ubonensis, and three undescribed species, comprising Candida aff. naeodendra/diddensiae Y151, Candida sp. GE19S08, and Yamadazyma sp. strain NYNU 22830. The sequences of the D1/D2 domains and ITS regions differed in nucleotide substitutions by 1.51% and 2.57% or greater, respectively, from those of the previously described and undescribed related species. In addition, the physiological characteristics of the novel species were distinct from those of the closely related described species. On the basis of these findings, we propose the name Yamadazyma thunbergiae sp. nov. to classify this species within the genus Yamadazyma. The holotype used is JCM 36746T (ex-type strains CBS 18614 and NBRC 116657). The MycoBank accession number is MB 853823.


Assuntos
DNA Fúngico , DNA Espaçador Ribossômico , Filogenia , Saccharomycetales , Análise de Sequência de DNA , Microbiologia do Solo , Japão , DNA Fúngico/genética , DNA Espaçador Ribossômico/genética , Saccharomycetales/genética , Saccharomycetales/classificação , Saccharomycetales/isolamento & purificação , Técnicas de Tipagem Micológica , Ácidos Graxos/química
2.
Artigo em Inglês | MEDLINE | ID: mdl-39235842

RESUMO

Two yeast strains, NYNU 236122 and NYNU 236180, were isolated from plant leaves collected in Tianchi Mountain, Henan Province, central China. Molecular phylogenetic analyses revealed the closest relatives of the strains are three described Kondoa species, Kondoa chamaenerii, Kondoa miscanthi, and Kondoa subrosea. Genetically, the isolated strains differed from the type strains of their three related species by 2-11(0.2-1.8%) base substitutions in the D1/D2 domain, 16-40 (2.6-5.6%) base mismatches in the internal transcribed spacer region, and more than 10.1% base substitutions in the partial RPB2 gene. Furthermore, the two strains differ physiologically from their closest related species, K. chamaenerii, in their ability to assimilate dl-lactate, nitrite, and l-lysine and their inability to assimilate nitrate. Additionally, they differ from K. miscanthi and K. subrosea in their ability to assimilate inulin, d-gluconate, and l-lysine. The species name of Kondoa tianchiensis f.a., sp. nov. is proposed with holotype CICC 33616T (Mycobank MB 853544).


Assuntos
DNA Fúngico , Filogenia , Folhas de Planta , Análise de Sequência de DNA , Folhas de Planta/microbiologia , China , DNA Fúngico/genética , Técnicas de Tipagem Micológica , Saccharomycetales/genética , Saccharomycetales/classificação , Saccharomycetales/isolamento & purificação , DNA Espaçador Ribossômico/genética
3.
Artigo em Inglês | MEDLINE | ID: mdl-39240062

RESUMO

Nineteen isolates representing a candidate for a novel yeast species belonging to the genus Spencermartinsiella were recovered from rotting wood samples collected at different sites in Atlantic Rainforest and Amazonian Forest ecosystems in Brazil. Similarity search of the nucleotide sequence of the intergenic spacer (ITS)-5.8S and large subunit D1/D2 regions of the ribosomal gene cluster showed that this novel yeast is closely related to Spencermartinsiella cellulosicola. The isolates differ by four nucleotide substitutions in the D1/D2 domain and six substitutions and 31 indels in the ITS region from the holotype of S. cellulosicola. Phylogenomic analysis based on 1474 single-copy orthologues for a set of Spencermartinsiella species whose whole genome sequences are available confirmed that the novel species is phylogenetically close to S. cellulosicola. The low average nucleotide identity value of 83% observed between S. cellulosicola and the candidate species confirms that they are distinct. The novel species produced asci with hemispherical ascospores. The name Spencermartinsiella nicolii sp. nov. is proposed. The holotype is CBS 14238T. The MycoBank number is MB855027. Interestingly, the D1/D2 sequence of the S. nicolii was identical to that of an uncultured strain of Spencermartinsiella causing systemic infection in a male adult crocodile (Crocodylus niloticus). The characterization of some virulence factors and antifungal susceptibility of S. nicolii isolates suggest that this yeast may be an opportunistic pathogen for animals, including humans; the isolates grow at 37 °C.


Assuntos
DNA Fúngico , Filogenia , Saccharomycetales , Análise de Sequência de DNA , Madeira , Brasil , Madeira/microbiologia , DNA Fúngico/genética , Saccharomycetales/genética , Saccharomycetales/isolamento & purificação , Saccharomycetales/classificação , Técnicas de Tipagem Micológica , DNA Espaçador Ribossômico/genética , Floresta Úmida , Florestas
4.
Curr Microbiol ; 81(10): 338, 2024 Sep 03.
Artigo em Inglês | MEDLINE | ID: mdl-39223407

RESUMO

During the COVID-19 pandemic, fungal infections, especially pulmonary aspergillosis, mucormycosis, and invasive candidiasis, have emerged as a significant health concern. Beyond Candida albicans, the most common cause of invasive candidiasis, other rare ascomycetous yeast species have been described in tertiary care units, potentially posing a broader health threat. We have isolated, from September 2020 to June 2021, nine Diutina catenulata strains from urine samples of six patients. This was intriguing as this fungus had not been previously identified in our institution, nor after June 2021. Therefore, we decided to outline the clinical features of the patients with this rare pathogen, to describe phenotypic characteristics, including antifungal susceptibility profiles, of this yeast species and to identify the genetic makeup through whole-genome sequencing analysis to evaluate if this was a cluster of genetically similar D. catenulata isolates in our institution. The strains were identified through MALDI-TOF MS analyses and Sanger sequencing of two rDNA regions. All patients yielding D. catenulata from urine samples needed ventilator support and used urinary catheters during hospitalization for treatment of COVID-19. None of them had received COVID-19 vaccines. Morphological and biochemical profiles of the nine strains were largely consistent, although fluconazole susceptibility varied, ranging from 4 to 32 µg/mL. Phylogenomic analysis revealed minimal genetic variation among the isolates, with low intrapopulation variation, supported by the identification of only 84 SNPs across all strains. Therefore, we propose that the yeast strains isolated were part of a cluster of D. catenulata funguria in the context of COVID-19.


Assuntos
Antifúngicos , COVID-19 , SARS-CoV-2 , Centros de Atenção Terciária , Humanos , COVID-19/microbiologia , COVID-19/epidemiologia , Centros de Atenção Terciária/estatística & dados numéricos , Brasil/epidemiologia , Masculino , Feminino , Pessoa de Meia-Idade , Antifúngicos/uso terapêutico , Antifúngicos/farmacologia , SARS-CoV-2/genética , SARS-CoV-2/efeitos dos fármacos , Idoso , Adulto , Filogenia , Testes de Sensibilidade Microbiana , Saccharomycetales/genética , Saccharomycetales/isolamento & purificação , Saccharomycetales/classificação , Sequenciamento Completo do Genoma
5.
Artigo em Inglês | MEDLINE | ID: mdl-39207228

RESUMO

Two yeast strains were isolated from rotting wood samples collected on Qingyuan Mountain, Fujian Province, PR China. Phylogenetic analysis, based on the concatenated sequences of the internal transcribed spacer (ITS) region and the D1/D2 domain of the large subunit rRNA gene, revealed that these two strains represent a novel species of the genus Cyberlindnera. The proposed name for this new species is Cyberlindnera qingyuanensis f.a., sp. nov. (holotype: GDMCC 2.300; ex-type: PYCC 9925) although the formation of ascospores was not observed. The novel species differs from its close relative Cyberlindnera galapagoensis by 7.7% sequence divergence (37 substitutions and seven indels) in the D1/D2 domain and 9.7% sequence divergence (42 substitutions and 34 indels) in the ITS region, respectively. Additionally, Cyb. qingyuanensis differs from its close relative Cyb. galapagoensis by its ability to grow in cellobiose, l-rhamnose, ribitol, galactitol, and dl-lactate, its growth at 37 °C, and its inability to ferment raffinose. The Mycobank number is MB 854693.


Assuntos
DNA Fúngico , DNA Espaçador Ribossômico , Filogenia , Saccharomycetales , Análise de Sequência de DNA , Madeira , Madeira/microbiologia , China , DNA Fúngico/genética , DNA Espaçador Ribossômico/genética , Técnicas de Tipagem Micológica , Saccharomycetales/genética , Saccharomycetales/classificação , Saccharomycetales/isolamento & purificação
6.
Microbiol Spectr ; 12(10): e0044424, 2024 Oct 03.
Artigo em Inglês | MEDLINE | ID: mdl-39162504

RESUMO

A yeast-like extremophile organism, Hansenula anomala, has been isolated from the superfund site the Berkeley Pit Lake in Butte, Montana. Studies demonstrate H. anomala growth in some of the known Berkeley Pit Lake solutes. Microbial growth dynamics under controlled conditions were compared of H. anomala for multiple metal concentrations. Each solute/metal was tested separately at previously reported concentrations on the geochemistry of the Berkeley Pit lake in the first 0.2 m in spring (pH 2.5). H. anomala grew well with sulfur (S), MgSO4, CaSO4, potassium chloride (KCl), and NaSO4 and was inhibited with FeSO4, MnSO4, CuSO4, AlSO4, or ZnSO4. With the addition of elemental S, growth was observed for FeSO4 indicating minimal growth rescue. PCR amplification of genomic DNA from the organism using known ribosomal primers indicates the strain to be ATCC8168 (CBS 5759). From this data, it can be concluded that H. anomala ATCC8168 from the Berkeley Pit is an extremophile that exhibits metal-specific growth.IMPORTANCELaboratory growth studies of a strain of Hansenula anomala from the Berkeley Pit have found the organism to be metal specific indicating some unique metabolism possibilities. These studies show that this strain is metal-dependent and provides information about the adaptable tolerance of organisms in superfund sites as well as giving a basis for future bioremediation development utilizing H. anomala.


Assuntos
Extremófilos , Extremófilos/metabolismo , Extremófilos/genética , Extremófilos/isolamento & purificação , Extremófilos/crescimento & desenvolvimento , Montana , Metais/metabolismo , Saccharomycetales/metabolismo , Saccharomycetales/genética , Saccharomycetales/isolamento & purificação , Saccharomycetales/crescimento & desenvolvimento , Saccharomycetales/classificação , Lagos/microbiologia
7.
Yeast ; 41(7): 437-447, 2024 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-38850070

RESUMO

Four yeast isolates were obtained from rotting wood and galleries of passalid beetles collected in different sites of the Brazilian Amazonian Rainforest in Brazil. This yeast produces unconjugated allantoid asci each with a single elongated ascospore with curved ends. Sequence analysis of the internal transcribed spacer-5.8 S region and the D1/D2 domains of the large subunit ribosomal RNA (rRNA) gene showed that the isolates represent a novel species of the genus Spathaspora. The novel species is phylogenetically related to a subclade containing Spathaspora arborariae and Spathaspora suhii. Phylogenomic analysis based on 1884 single-copy orthologs for a set of Spathaspora species whose whole genome sequences are available confirmed that the novel species represented by strain UFMG-CM-Y285 is phylogenetically close to Sp. arborariae. The name Spathaspora marinasilvae sp. nov. is proposed to accommodate the novel species. The holotype of Sp. marinasilvae is CBS 13467 T (MycoBank 852799). The novel species was able to accumulate xylitol and produce ethanol from d-xylose, a trait of biotechnological interest common to several species of the genus Spathaspora.


Assuntos
Besouros , Filogenia , Floresta Úmida , Saccharomycetales , Madeira , Xilose , Animais , Madeira/microbiologia , Besouros/microbiologia , Brasil , Saccharomycetales/genética , Saccharomycetales/classificação , Saccharomycetales/isolamento & purificação , Saccharomycetales/metabolismo , Xilose/metabolismo , Fermentação , DNA Fúngico/genética , Análise de Sequência de DNA
8.
Artigo em Inglês | MEDLINE | ID: mdl-38713197

RESUMO

Two isolates representing a novel species of the genus Wickerhamiella were obtained in India from nectar of flowers of Lantana camara, an ornamental exotic species native to Central and South America. Phylogenetic analyses of the D1/D2 domain of the 26S large subunit (LSU) rRNA gene, internal transcribed spacer (ITS) region, and physiological characteristics, supported the recognition of the novel species, that we designate Wickerhamiella lachancei sp. nov (MycoBank no. MB851709), with MCC 9929T as the holotype and PYCC 10003T as the isotype. Considering pairwise sequence similarity, the type strain of the novel species differs from the type strain of the most closely related species, Wickerhamiella drosophilae CBS 8459T, by 16 nucleotide substitutions and two gaps (3.9 % sequence variation) in the D1/D2 region (560 bp compared) and 28 nucleotide substitutions and five gaps (7.22 % sequence variation) in the ITS region (444 bp compared).


Assuntos
DNA Fúngico , DNA Espaçador Ribossômico , Flores , Lantana , Filogenia , Análise de Sequência de DNA , Índia , Flores/microbiologia , DNA Fúngico/genética , Lantana/microbiologia , DNA Espaçador Ribossômico/genética , Dados de Sequência Molecular , Técnicas de Tipagem Micológica , RNA Ribossômico/genética , Saccharomycetales/genética , Saccharomycetales/isolamento & purificação , Saccharomycetales/classificação
9.
J Infect Dev Ctries ; 18(4): 636-639, 2024 Apr 30.
Artigo em Inglês | MEDLINE | ID: mdl-38728631

RESUMO

INTRODUCTION: Kodamaea ohmeri is a rare, recognized pathogen that has previously been isolated from environmental sources. The patients commonly affected by this yeast include immunocompromised as well as immunocompetent patients having several associated risk factors. METHODOLOGY: We report three cases in which K. ohmeri was isolated from blood using Bact T/ALERT. Identification was carried out by MALDI-TOF MS (Vitek-MS, BioMérieux, Marcy-l'Etoile, France) in addition to color characteristics on chromogenic media. The patients had diminished immune response on account of a multitude of comorbidities. RESULTS: K. ohmeri can be misidentified as Candida tropicalis, Candida albicans, or Candida hemolounii by conventional methods; correct and timely identification can be achieved by MALDI-TOF MS. Antifungal susceptibility breakpoints for K. ohmeri are currently not defined. An Echinocandin was added to the treatment regimen of all three of the cases. CONCLUSIONS: Identification of K. ohmeri using conventional methods is difficult and unusual yeasts should be carefully observed, especially upon prolonged incubation.


Assuntos
Antifúngicos , Hospedeiro Imunocomprometido , Saccharomycetales , Espectrometria de Massas por Ionização e Dessorção a Laser Assistida por Matriz , Humanos , Antifúngicos/uso terapêutico , Antifúngicos/farmacologia , Masculino , Saccharomycetales/isolamento & purificação , Saccharomycetales/efeitos dos fármacos , Feminino , Pessoa de Meia-Idade , Idoso , Infecções Fúngicas Invasivas/tratamento farmacológico , Infecções Fúngicas Invasivas/diagnóstico , Infecções Fúngicas Invasivas/microbiologia , Técnicas Microbiológicas
10.
Braz J Microbiol ; 55(3): 2149-2167, 2024 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-38775906

RESUMO

This study explored the isolation and screening of an osmotolerant yeast, Wickerhamomyces anomalus BKK11-4, which is proficient in utilizing renewable feedstocks for sugar alcohol production. In batch fermentation with high initial glucose concentrations, W. anomalus BKK11-4 exhibited notable production of glycerol and arabitol. The results of the medium optimization experiments revealed that trace elements, such as H3BO3, CuSO4, FeCl3, MnSO4, KI, H4MoNa2O4, and ZnSO4, did not increase glucose consumption or sugar alcohol production but substantially increased cell biomass. Osmotic stress, which was manipulated by varying initial glucose concentrations, influenced metabolic outcomes. Elevated glucose levels promoted glycerol and arabitol production while decreasing citric acid production. Agitation rates significantly impacted the kinetics, enhancing glucose utilization and metabolite production rates, particularly for glycerol, arabitol, and citric acid. The operational pH dictated the distribution of the end metabolites, with glycerol production slightly reduced at pH 6, while arabitol production remained unaffected. Citric acid production was observed at pH 6 and 7, and acetic acid production was observed at pH 7. Metabolomic analysis using GC/MS identified 29 metabolites, emphasizing the abundance of sugar/sugar alcohols. Heatmaps were generated to depict the variations in metabolite levels under different osmotic stress conditions, highlighting the intricate metabolic dynamics occurring post-glucose uptake, affecting pathways such as the pentose phosphate pathway and glycerolipid metabolism. These insights contribute to the optimization of W. anomalus BKK11-4 as a whole-cell factory for desirable products, demonstrating its potential applicability in sustainable sugar alcohol production from renewable feedstocks.


Assuntos
Fermentação , Glicerol , Saccharomycetales , Álcoois Açúcares , Glicerol/metabolismo , Álcoois Açúcares/metabolismo , Saccharomycetales/metabolismo , Saccharomycetales/isolamento & purificação , Glucose/metabolismo , Pressão Osmótica , Concentração de Íons de Hidrogênio
11.
Artigo em Inglês | MEDLINE | ID: mdl-38780584

RESUMO

Four yeast strains belonging to the basidiomycetous yeast genus Mrakia were isolated from diverse habitats in the Ny-Ålesund region (Svalbard, High Arctic): two from vascular plants, one from seawater and one from freshwater. Phylogenetic analysis, based on the ITS region and the D1/D2 domain of the 28S rRNA gene, identified these four strains as representing two novel species within the genus Mrakia. The names Mrakia polaris sp. nov. (MycoBank number: MB 852063) and Mrakia amundsenii sp. nov. (MycoBank number: MB 852064) are proposed. These two new species show distinct psychrophilic adaptations, as they exhibit optimal growth at temperatures between 10 and 15°C, while being unable to grow at 25°C. The holotype of M. polaris sp. nov. is CPCC 300345T, and the holotype of M. amundsenii sp. nov. is CPCC 300572T.


Assuntos
DNA Fúngico , Filogenia , Água do Mar , Análise de Sequência de DNA , Regiões Árticas , DNA Fúngico/genética , Água do Mar/microbiologia , Técnicas de Tipagem Micológica , Svalbard , RNA Ribossômico 28S/genética , Basidiomycota/genética , Basidiomycota/classificação , Basidiomycota/isolamento & purificação , Água Doce/microbiologia , Ecossistema , Temperatura Baixa , Saccharomycetales/classificação , Saccharomycetales/genética , Saccharomycetales/isolamento & purificação
12.
Indian J Pathol Microbiol ; 67(3): 654-657, 2024 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-38391359

RESUMO

ABSTRACT: Kodamaea ohmeri is a rare opportunistic pathogen belonging to Saccharomycetes family. This yeast was also formerly known as Yamadazyma ohmeri or Pichia ohmeri . This opportunistic pathogen causes illness that typically affects people with impaired immune system. In this report, we discuss a fatal case involving a woman in her late 30s who was admitted to the hospital on the sixth day of her sickness after being given a COVID-19 Category 5A diagnosis. For COVID-19, she received subcutaneous heparin, cefuroxime, and intravenous corticosteroids. She was diagnosed with secondary bacterial and fungal infections in the ICU. Multiple antibiotics and antifungal were given to treat bacterial and fungal infections. An unusual fungus, Kodamaea ohmeri , was isolated from the clinical sample. On day 36, she succumbed to her infection in the ICU. The cause of death was multidrug-resistant sepsis with multiple organ failures due to COVID-19 infection, worsened by an embolism and trachea damage during a tracheostomy. To effectively manage K. ohmeri , clinicians and microbiologists must identify and be aware of this emerging human opportunistic pathogen, which can co-infect debilitated patients such as COVID-19 patients, for effective management.


Assuntos
COVID-19 , SARS-CoV-2 , Humanos , Feminino , COVID-19/complicações , Evolução Fatal , Adulto , Malásia , Micoses/tratamento farmacológico , Micoses/diagnóstico , Micoses/microbiologia , Saccharomycetales/isolamento & purificação , Saccharomycetales/efeitos dos fármacos , Saccharomycetales/patogenicidade , Antifúngicos/uso terapêutico , Coinfecção/microbiologia , Infecções Oportunistas/tratamento farmacológico , Infecções Oportunistas/microbiologia
13.
World J Pediatr Congenit Heart Surg ; 13(4): 523-525, 2022 07.
Artigo em Inglês | MEDLINE | ID: mdl-35296172

RESUMO

We report a case of endocarditis months after a Bentall procedure. This was caused by Candida Lusitaniae, in an immunocompetent patient with a recent SARS-CoV-2 infection. The patient underwent a new Bentall procedure. SARS-CoV-2 has been associated with co-infection by Candida species since the beginning of the pandemic, nevertheless, Candida Lusitaniae remains a very uncommon causative agent of prosthetic endocarditis. We suggest a possible role of the SARS-CoV-2, which may have delayed the diagnosis of endocarditis and the appropriate therapy.


Assuntos
Procedimentos Cirúrgicos Cardíacos , Endocardite , Saccharomycetales , COVID-19/epidemiologia , Procedimentos Cirúrgicos Cardíacos/efeitos adversos , Endocardite/diagnóstico , Endocardite/microbiologia , Humanos , Hospedeiro Imunocomprometido , Saccharomycetales/isolamento & purificação
14.
Artigo em Inglês | MEDLINE | ID: mdl-35044902

RESUMO

Strains SU22T (TBRC 14875T) and FLA11.5, representing a novel anamorphic yeast species, were respectively isolated from a fruiting body of a Coprinus species and an inflorescence of a Coffea species collected in Thailand. Analysis of the sequences of the D1/D2 domains of the large subunit (LSU) rRNA gene and the internal transcribed spacer (ITS) regions showed that the two strains differed by two nucleotide substitutions in the D1/D2 domains of the LSU rRNA gene and were identical in the ITS regions. Wickerhamiella drosophilae CBS 8459T was the most closely related species, but with 24-26 nucleotide substitutions in the D1/D2 domains of the LSU rRNA gene and 24 nucleotide substitutions in the ITS regions. A phylogenetic analysis, based on the sequences of the D1/D2 domains, indicated that the two strains represented a species in the genus Wickerhamiella which was distinct from other recognized species of the genus. Therefore, the two strains were assigned as a novel species, for which we propose the name Wickerhamiella nakhonpathomensis f.a. sp. nov. The holotype is TBRC 14875T (isotype PYCC 8914T). The MycoBank number of the novel species is MB 840833.


Assuntos
Agaricales , Flores/microbiologia , Filogenia , Saccharomycetales , DNA Fúngico/genética , DNA Espaçador Ribossômico/genética , Ácidos Graxos/química , Técnicas de Tipagem Micológica , Saccharomycetales/classificação , Saccharomycetales/isolamento & purificação , Análise de Sequência de DNA , Tailândia
15.
World J Microbiol Biotechnol ; 38(2): 35, 2022 Jan 06.
Artigo em Inglês | MEDLINE | ID: mdl-34989919

RESUMO

Aiming to broaden the base of knowledge about wild yeasts, four new indigenous strains were isolated from corn residues, and phylogenetic-tree assemblings on ITS and LSU regions indicated they belong to Meyerozyma caribbica. Yeasts were cultivated under full- and micro-aerobiosis, starting with low or high cell-density inoculum, in synthetic medium or corn hydrolysate containing glucose and/or xylose. Cells were able to assimilate both monosaccharides, albeit by different metabolic routes (fermentative or respiratory). They grew faster in glucose, with lag phases ~ 10 h shorter than in xylose. The hexose exhaustion occurred between 24 and 34 h, while xylose was entirely consumed in the last few hours of cultivation (44-48 h). In batch fermentation in synthetic medium with high cell density, under full-aerobiosis, 18-20 g glucose l-1 were exhausted in 4-6 h, with a production of 6.5-7.0 g ethanol l-1. In the xylose medium, cells needed > 12 h to consume the carbohydrate, and instead of ethanol, cells released 4.4-6.4 g l-1 xylitol. Under micro-aerobiosis, yeasts were unable to assimilate xylose, and glucose was more slowly consumed, although the ethanol yield was the theoretical maximum. When inoculated into the hydrolysate, cells needed 4-6 h to deplete glucose, and xylose had a maximum consumption of 57%. Considering that the hydrolysate contained ~ 3 g l-1 acetic acid, it probably has impaired sugar metabolism. Thus, this study increases the fund of knowledge regarding indigenous yeasts and reveals the biotechnological potential of these strains.


Assuntos
Glucose/metabolismo , Saccharomycetales/metabolismo , Xilose/metabolismo , Zea mays/microbiologia , Ácido Acético , Aerobiose , Biomassa , Meios de Cultura/química , Fermentação , Lignina , Filogenia , Saccharomycetales/classificação , Saccharomycetales/genética , Saccharomycetales/isolamento & purificação , Xilitol/biossíntese
16.
Artigo em Inglês | MEDLINE | ID: mdl-35037847

RESUMO

Seven yeast strains, representing a single novel anamorphic species, were isolated in Thailand. They consisted of five strains (DMKU-MRY16T, DMKU-SK18, DMKU-SK25, DMKU-SK30 and DMKU-SK32) obtained from five different mushrooms, and two strains (ST-224 and 11-14.2) derived from insect frass and soil, respectively. The pairwise sequence analysis indicated that all seven strains had identical sequences in the D1/D2 domains of the large subunit (LSU) rRNA gene and the internal transcribed spacer (ITS) region. Metahyphopichia silvanorum was the most closely related species, but with 11.9-12.4% nucleotide substitutions in the D1/D2 domains of the LSU rRNA gene and 13.1-13.3% nucleotide substitutions in the ITS region. The phylogenetic analyses based on the concatenated sequences of the ITS region and the D1/D2 domains of the LSU rRNA gene showed that the seven strains form a well-separated subclade in a clade containing M. silvanorum and Metahyphopichia laotica with high bootstrap support. A phylogenetic analysis of a multilocus dataset including the small subunit (SSU) rRNA gene, the ITS region, the D1/D2 domains of the LSU rRNA gene, translation elongation factor 1-alpha gene, actin gene and the RNA polymerase II subunit 2 gene, confirmed the presence of the monophyletic clade that also includes M. silvanorum and M. laotica, and strongly supported the phylogenetic isolation of the seven strains from its neighbouring species. Therefore, the seven strains were assigned as a single novel species of the genus Metahyphopichia, according to their phylogenetic relationships. The name Metahyphopichia suwanaadthiae sp. nov. is proposed to accommodate the seven strains. The holotype is DMKU-MRY16T (TBRC 11775T=NBRC 114386T=PYCC 8655T). The MycoBank number of the novel species is MB 841280. In addition, Candida silvanorum is reassigned to the genus Metahyphopichia. The MycoBank number of M. silvanorum comb. nov. is MB 841279.


Assuntos
Candida/classificação , Filogenia , Saccharomycetales , DNA Fúngico/genética , DNA Espaçador Ribossômico/genética , Técnicas de Tipagem Micológica , RNA Ribossômico 16S/genética , Saccharomycetales/classificação , Saccharomycetales/isolamento & purificação , Análise de Sequência de DNA , Tailândia
17.
Food Microbiol ; 101: 103894, 2022 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-34579854

RESUMO

In the present study, for the first time, high sensitive quantitative polymerase chain reaction (qPCR) and digital droplet polymerase chain reaction (ddPCR) assays were developed to detect and quantify total eumycetes with potential application in several food matrices and to specifically determine the level of contamination by Saccharomycopsis fibuligera and Wickerhamomyces anomalus cells directly in bread. Among the candidate target genes used to develop the assays, car1 gene was chosen to detect the two spoilage yeasts S. fibuligera and W. anomalus. The specificity of the PCR assays was tested using purified genomic DNA from 36 bacterial and fungal strains. The sensitivity of the assays was defined by using tenfold serial dilutions of genomic DNA starting from 106 cfu/mL to 1 cfu/mL of S. fibuligera and W. anomalus. Validation of the assays was achieved by enumeration of S. fibuligera and W. anomalus DNA copies from samples of artificially contaminated bread homogenates detecting up to 10 cfu/mL (0.06 ± 0.01 copies/µL) of W. anomalus by using ddPCR. In conclusion, the developed qPCR and ddPCR assays demonstrate strong performance in the early detection of S. fibuligera and W. anomalus in bread, representing promising tools for applying high-throughput approaches to regularly monitor bread quality.


Assuntos
Pão , Contaminação de Alimentos/análise , Saccharomycetales/isolamento & purificação , Saccharomycopsis , Pão/microbiologia , Reação em Cadeia da Polimerase em Tempo Real , Saccharomycopsis/isolamento & purificação , Sensibilidade e Especificidade , Leveduras
18.
J Clin Microbiol ; 60(1): e0160721, 2022 01 19.
Artigo em Inglês | MEDLINE | ID: mdl-34669454

RESUMO

Magnusiomyces and Geotrichum species are ascomycetous yeasts that can cause potentially life-threatening invasive fungal infections commonly referred to as geotrichosis. In this study, we aimed to estimate the incidence and mortality of these infections in a German tertiary care center. Furthermore, we evaluated the suitability of the fungal biomarkers galactomannan (GM) and ß-1,3-d-glucan (BDG), which are both recommended as surrogate markers for Magnusiomyces capitatus infection by the European Society of Clinical Microbiology and Infectious Diseases (ESCMID) and the European Confederation of Medical Mycology (ECMM) joint clinical guidelines for the diagnosis and management of rare invasive yeast infections for detection of invasive geotrichosis. Cases meeting the inclusion criteria for invasive Magnusiomyces/Geotrichum infection were retrospectively identified. Serum samples and culture supernatants were analyzed with two commercially available fungal antigen tests (Platelia Aspergillus Ag EIA and Wako ß-glucan test). For a control cohort, outpatient samples sent for lues testing were included. Thirty-eight cases of Magnusiomyces/Geotrichum infection were identified over an 11-year observation period. In the majority of cases, the fungus was isolated from intra-abdominal specimens of patients with a history of abdominal surgery/procedures (n = 32). All cases of fungemia occurred exclusively in haemato-oncologic patients (n = 14). Thirty-day survival was 42% in the fungemia and 43% in the intra-abdominal geotrichosis group. Serum samples were available for 23 patients (14 bloodstream and nine intra-abdominal infections). While BDG sensitivity was 65%, none of the sera was GM positive. This finding was supported by in vitro experiments analyzing fungal culture supernatants: M. capitatus secretes significant amounts of BDG but not GM. Specificity was 96% for BDG and 100% for GM. Magnusiomyces and Geotrichum infections are not limited to haemato-oncologic patients. Contrasting the current ESCMID/ECMM recommendation, our results indicate that GM is no suitable biomarker for the diagnosis of Magnusiomyces infection. Contrarily, BDG sensitivity is comparable to that of candidemia.


Assuntos
Geotricose , Geotrichum , Infecções Fúngicas Invasivas , Mananas , Proteoglicanas , Saccharomycetales , beta-Glucanas , Biomarcadores/sangue , Galactose/análogos & derivados , Geotricose/sangue , Geotricose/diagnóstico , Geotrichum/isolamento & purificação , Humanos , Infecções Fúngicas Invasivas/sangue , Infecções Fúngicas Invasivas/diagnóstico , Mananas/sangue , Proteoglicanas/sangue , Estudos Retrospectivos , Saccharomycetales/isolamento & purificação , Sensibilidade e Especificidade , beta-Glucanas/sangue
19.
Int J Syst Evol Microbiol ; 71(11)2021 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-34762580

RESUMO

Four yeast isolates with an affinity to the genus Wickerhamiella were obtained from beach sand, a marine zoanthid and a tree exudate at different localities in Brazil. Two other isolates with almost identical ITS and D1/D2 sequences of the large subunit rRNA gene were isolated from the small intestine of cattle and a grease trap in Thailand. These isolates represent a novel species phylogenetically related to Wickerhamiella verensis, Wickerhamiella osmotolerans, Wickerhamiella tropicalis, Wickerhamiella sorbophila and Wickerhamiella infanticola. The novel species differs by 15-30 nucleotide differences from these species in the D1/D2 sequences. The name Wickerhamiella martinezcruziae f.a., sp. nov. is proposed. The holotype of Wickerhamiella martinezcruziae sp. nov. is CBS 16104T. The MycoBank number is MB 839328.


Assuntos
Filogenia , Saccharomycetales , Animais , Composição de Bases , Brasil , Bovinos/microbiologia , DNA Fúngico/genética , DNA Espaçador Ribossômico/genética , Intestino Delgado/microbiologia , Técnicas de Tipagem Micológica , Exsudatos de Plantas , RNA Ribossômico 16S/genética , Saccharomycetales/classificação , Saccharomycetales/isolamento & purificação , Areia/microbiologia , Análise de Sequência de DNA , Tailândia , Clima Tropical
20.
FEMS Microbiol Lett ; 368(20)2021 11 27.
Artigo em Inglês | MEDLINE | ID: mdl-34755861

RESUMO

Non-Saccharomyces yeasts are important players during winemaking and may come from grapes grown in vineyards. To study the diversity of non-Saccharomyces yeasts on grape berry surfaces, 433 strains were isolated from different Cabernet Sauvignon vineyards grown in Henan Province. Our results demonstrated that these strains were classified into 16 morphotypes according to their growth morphology on Wallerstein Laboratory agar medium, and were identified as seven species from four genera-Hanseniaspora opuntiae, Hanseniaspora vineae, Hanseniaspora uvarum, Pichia occidentalis, Pichia kluyveri, Issatchenkia terricola and Saturnispora diversa-based on a series of molecular biological experiments. Hanseniaspora opuntiae was obtained from all sampling sites except Changyuan County, while Pichia kluyveri and Saturnispora diversa were only found in sites of Zhengzhou Grape Resource Garden and Minquan County, respectively. The site Minquan was home of the greatest species richness, while only one single species (Hanseniaspora opuntiae) was detected at NAPA winery from Zhengzhou or at Anyang County. Finally, this study suggested that the geographic distribution and diversity of non-Saccharomyces yeast populations on Cabernet Sauvignon grape berries were likely to be determined by a combination of grape varieties and environmental factors.


Assuntos
Biodiversidade , Frutas , Vitis , Leveduras , China , Fazendas , Fermentação , Frutas/microbiologia , Hanseniaspora/classificação , Hanseniaspora/isolamento & purificação , Pichia/classificação , Pichia/isolamento & purificação , Saccharomycetales/classificação , Saccharomycetales/isolamento & purificação , Vitis/microbiologia , Vinho/microbiologia , Leveduras/classificação , Leveduras/isolamento & purificação
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