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1.
World J Microbiol Biotechnol ; 35(12): 180, 2019 Nov 14.
Artigo em Inglês | MEDLINE | ID: mdl-31728755

RESUMO

Derived from RNA, 5'-ribonucleotides, especially Inosine-5'-monophosphate (IMP) and guanosine-5'-monophosphate (GMP), can enhance the umami taste of soy sauce. In this study, the RNA content of three different salt-tolerant yeasts was examined. The most valuable strain was subjected to atmospheric and room-temperature plasma (ARTP) mutagenesis, which improved its RNA content by 160.54%. Regular fermentation with RNA-enhanced strain failed to increase the amount of 5'-ribonucleotides in the soy sauce due to hydrolysis by phosphatase. A two-stage fermentation strategy was then carried out. Aroma compounds were mainly synthesized in the first stage, and RNA-enriched biomass was massively produced in the second stage followed by heat treatment to inactivate phosphatase. After the proposed strategy was applied, IMP and GMP in the soy sauce reached 68.54 and 89.37 mg/L, respectively. Moreover, the amounts of key aroma compounds and organic acids significantly increased. Results may provide new insights for improving the quality of soy sauce through microorganism breeding and fermentation control.


Assuntos
Mutagênese , Gases em Plasma , RNA , Tolerância ao Sal/genética , Tolerância ao Sal/efeitos da radiação , Alimentos de Soja , Zygosaccharomyces/genética , Zygosaccharomyces/efeitos da radiação , Cruzamento , Fermentação , Microbiologia de Alimentos , Cloreto de Sódio , Paladar , Temperatura Ambiente , Zygosaccharomyces/fisiologia
2.
FEMS Yeast Res ; 18(7)2018 11 01.
Artigo em Inglês | MEDLINE | ID: mdl-30052970

RESUMO

Interspecies hybridization is an important evolutionary mechanism in yeasts. The genus Zygosaccharomyces in particular contains numerous hybrid strains and/or species. Here, we investigated the genome of Zygosaccharomyces strain MT15, an isolate from Maotai-flavor Chinese liquor fermentation. We found that it is an interspecies hybrid and identified it as Zygosaccharomyces pseudobailii. The Z. bailii species complex consists of three species: Z. bailii, which is not a hybrid and whose 10 Mb genome is designated 'A', and two hybrid species Z. parabailii ('AB' genome, 20 Mb) and Z. pseudobailii ('AC' genome, 20 Mb). The A, B and C subgenomes are all approximately 7%-10% different from one another in nucleotide sequence, and are derived from three different parental species. Despite being hybrids, Z. pseudobailii and Z. parabailii are capable of mating and sporulating. We previously showed that Z. parabailii regained fertility when one copy of its MAT locus became broken into two parts, causing the allodiploid hybrid to behave as a haploid gamete. In Z. pseudobailii, we find that a very similar process occurred after hybridization, when a deletion of 1.5 kb inactivated one of the two copies of its MAT locus. The half-sibling species Z. parabailii and Z. pseudobailii therefore went through remarkably parallel but independent steps to regain fertility after they were formed by separate interspecies hybridizations.


Assuntos
Genes Fúngicos Tipo Acasalamento/genética , Hibridização Genética , Deleção de Sequência , Zygosaccharomyces/genética , Sequência de Bases , Evolução Biológica , Mapeamento Cromossômico , Fertilidade/genética , Genoma Fúngico/genética , Haploidia , Filogenia , Zygosaccharomyces/classificação , Zygosaccharomyces/fisiologia
3.
J Econ Entomol ; 111(5): 2081-2088, 2018 09 26.
Artigo em Inglês | MEDLINE | ID: mdl-30053163

RESUMO

Yeasts from all immature life stages of Mexican fruit fly Anastrepha ludens (Loew) (Diptera: Tephritidae) from diet, insectary air, and rearing materials were isolated, identified and evaluated for pathogenicity. Fifteen species of yeasts with one to genus level were identified from 72 yeast cultures obtained. Zygosaccharomyces bailii was the only yeast found to be highly pathogenic to Mexican fruit fly. Seventy-two hours post inoculation, the diet in bioassay cups with Z. bailii consistently showed signs of fermentation with gas bubbling causing the migration of larvae to the walls and lids of bioassay cups. The spent diet from Z. balii-infested cups was crusty, cracked and had a pasty layer. Many larvae were small, moribund, and discolored, appearing caramel or blackish. Insect yield loss with Z. bailii in comparison to that of control ranged from 10 to 44% for larvae and 14 to 47% for pupae. Additionally, Z. bailii caused a reduction in mean pupal weight. The weakly pathogenic yeasts produced significantly less yield of larvae and pupae than the nonpathogenic ones included Trichosporon montevideense, Clavispora lucitaniae, Candida sp., C. rugosa, and Rhodotorula mucilaginosa. Yield loss of larvae caused by this group ranged from 12 (C. lusitaniae) to 18% (R. mucilaginosa). Yield losses for pupa were similar to that of larvae. The mean pupa weight for these species was above the minimum acceptable (16.50 mg) for the SIT program. The nonpathogenic yeast produced yields of larvae and pupae similar to the control included Cryptococcus diffluens, Pichia kudriavzevii, Meyerozyma guilliermondii, Wickerhamomyces anomalus, Trichosporon asahii, Debaryomyces hansenii, Candida tropicalis, Cryptococcus sp., Candida parapsilosis, and Hanseniaspora opuntiae. In conclusion, the identification and management of insect pathogenic yeasts, such as Z. balii in mass rearing systems of Mexican fruit fly must be considered to avoid their potential negative effects.


Assuntos
Interações Hospedeiro-Patógeno , Tephritidae/microbiologia , Zygosaccharomyces/patogenicidade , Animais , Tephritidae/crescimento & desenvolvimento , Zygosaccharomyces/fisiologia
4.
Food Chem ; 254: 201-207, 2018 Jul 15.
Artigo em Inglês | MEDLINE | ID: mdl-29548443

RESUMO

This work aimed to evaluate the effects of dielectric barrier discharge (DBD) plasma on inactivation of spoilage yeast Zygosaccharomyces rouxii (Z. rouxii), in apple juice. Results showed that DBD plasma treatment at 90 W for 140 s resulted in about 5-log reduction of Z. rouxii in apple juice. The levels of extracellular nucleic acids and proteins as well as contents of H2O2 and NO2- in yeast extract-peptone-dextrose (YPD) medium increased significantly after DBD plasma treatment at 90 W for 40-200 s. The increases in membrane permeability and generation of reactive species would likely contribute to DBD plasma-mediated inactivation of Z. rouxii. DBD plasma caused significant changes in pH, titratable acidity, and certain color parameters of apple juice, but had no effect on the contents of total soluble solids, reducing sugar, and total phenolics. This study provides key implications for the application of DBD plasma in fruit juice processing.


Assuntos
Sucos de Frutas e Vegetais/microbiologia , Malus/química , Viabilidade Microbiana/efeitos dos fármacos , Gases em Plasma/farmacologia , Zygosaccharomyces/efeitos dos fármacos , Zygosaccharomyces/fisiologia , Impedância Elétrica , Sucos de Frutas e Vegetais/análise
5.
Appl Environ Microbiol ; 84(1)2018 01 01.
Artigo em Inglês | MEDLINE | ID: mdl-29079616

RESUMO

In soy sauce manufacturing, Candida versatilis plays a role in the production of volatile flavor compounds, such as volatile phenols, but limited accessible information on its genome has prevented further investigation regarding aroma production and breeding. Although the draft genome sequence data of two strains of C. versatilis have recently been reported, these strains are not similar to each other. Here, we reassess the draft genome sequence data for strain t-1, which was originally reported to be C. versatilis, and conclude that strain t-1 is most probably not C. versatilis but a gamete of hybrid Zygosaccharomyces rouxii Phylogenetic analysis of the D1/D2 region of the 26S ribosomal DNA (rDNA) sequence indicated that strain t-1 is more similar to the genus Zygosaccharomyces than to C. versatilis Moreover, we found that the genome of strain t-1 is composed of haploid genome content and divided into two regions that show approximately 100% identity with the T or P subgenome derived from the natural hybrid Zygosaccharomyces rouxii, such as NBRC110957 and NBRC1876. We also found a chromosome crossing-over signature in the scaffolds of strain t-1. These results suggest that strain t-1 is a gamete of the hybrid Z. rouxii, generated by either meiosis or chromosome loss following reciprocal translocation between the T and P subgenomes. Although it is unclear why strain t-1 was misidentified as C. versatilis, the genome of strain t-1 has broad implications for considering the evolutionary fate of an allodiploid.IMPORTANCE In yeast, crossing between different species sometimes leads to interspecies hybrids. The hybrid generally cannot produce viable spores because dissimilarity of parental genomes prevents normal chromosome segregation during meiotic division, leading to a dead end. Thus, only a few natural cases of homoploid hybrid speciation, which requires mating between 1n gametes of hybrids, have been described. However, a recent study provided strong evidence that homoploid hybrid speciation is initiated in natural populations of the budding yeast, suggesting the potential presence of viable 1n gametes of hybrids. The significance of our study is finding that the strain t-1, which had been misidentified as Candida versatilis, is a viable 1n gamete derived from hybrid Zygosaccharomyces rouxii.


Assuntos
Candida/fisiologia , DNA Fúngico/análise , RNA Ribossômico/análise , Zygosaccharomyces/classificação , Zygosaccharomyces/fisiologia , Evolução Biológica , Candida/classificação , Hibridização Genética , Filogenia
6.
Appl Environ Microbiol ; 84(5)2018 03 01.
Artigo em Inglês | MEDLINE | ID: mdl-29269498

RESUMO

Lactic acid has a wide range of applications starting from its undissociated form, and its production using cell factories requires stress-tolerant microbial hosts. The interspecies hybrid yeast Zygosaccharomyces parabailii has great potential to be exploited as a novel host for lactic acid production, due to high organic acid tolerance at low pH and a fermentative metabolism with a high growth rate. Here we used mRNA sequencing (RNA-seq) to analyze Z. parabailii's transcriptional response to lactic acid added exogenously, and we explore the biological mechanisms involved in tolerance. Z. parabailii contains two homeologous copies of most genes. Under lactic acid stress, the two genes in each homeolog pair tend to diverge in expression to a significantly greater extent than under control conditions, indicating that stress tolerance is facilitated by interactions between the two gene sets in the hybrid. Lactic acid induces downregulation of genes related to cell wall and plasma membrane functions, possibly altering the rate of diffusion of lactic acid into cells. Genes related to iron transport and redox processes were upregulated, suggesting an important role for respiratory functions and oxidative stress defense. We found differences in the expression profiles of genes putatively regulated by Haa1 and Aft1/Aft2, previously described as lactic acid responsive in Saccharomyces cerevisiae Furthermore, formate dehydrogenase (FDH) genes form a lactic acid-responsive gene family that has been specifically amplified in Z. parabailii in comparison to other closely related species. Our study provides a useful starting point for the engineering of Z. parabailii as a host for lactic acid production.IMPORTANCE Hybrid yeasts are important in biotechnology because of their tolerance to harsh industrial conditions. The molecular mechanisms of tolerance can be studied by analyzing differential gene expression under conditions of interest and relating gene expression patterns to protein functions. However, hybrid organisms present a challenge to the standard use of mRNA sequencing (RNA-seq) to study transcriptional responses to stress, because their genomes contain two similar copies of almost every gene. Here we used stringent mapping methods and a high-quality genome sequence to study the transcriptional response to lactic acid stress in Zygosaccharomyces parabailii ATCC 60483, a natural interspecies hybrid yeast that contains two complete subgenomes that are approximately 7% divergent in sequence. Beyond the insights we gained into lactic acid tolerance in this study, the methods we developed will be broadly applicable to other yeast hybrid strains.


Assuntos
Ácido Láctico/metabolismo , Transcrição Genética/fisiologia , Zygosaccharomyces/fisiologia , RNA Fúngico/análise , RNA Mensageiro/análise , Análise de Sequência de RNA , Estresse Fisiológico , Zygosaccharomyces/genética
7.
Appl Environ Microbiol ; 83(21)2017 11 01.
Artigo em Inglês | MEDLINE | ID: mdl-28842546

RESUMO

The mechanism of whole-genome duplication (WGD) in yeast has been intensively studied because it has a large impact on yeast evolution. WGD has shaped the genomic architecture of modern Saccharomyces cerevisiae; however, the mechanism for restoring fertility after interspecies hybridization, which would be involved in the process of WGD, has not been thoroughly elucidated. In this study, we obtained a draft genome sequence of the salt-tolerant yeast Zygosaccharomyces rouxii NBRC110957 and revealed that it is a hybrid lineage of Z. rouxii (allodiploid) with two subgenomes equivalent to NBRC1876. Because this allodiploid yeast can mate with other allodiploid strains and form spores, it can be a good model of restoring fertility after interspecies hybridization. We observed that NBRC110957 and NBRC1876 contain six mating-type-like (MTL) loci. There are no large deletions or deleterious mutations in MTL loci, except for several-base-pair deletions in the X region in certain MTL loci. We also assigned only one mating-type (MAT) locus that exclusively determines mating types from six MTL loci. These results suggest that it is possible to recover mating competence regardless of whether cells lose one MAT locus through random gene loss by mitotically dividing after interspecies hybridization. Moreover, we propose that perturbation of gene expression and substantial breakdown of MAT heterozygosity caused by chromosomal rearrangement at MTL loci play roles in restoring the mating competence of allodiploids. This scenario can provide a mechanism for restoring fertility after interspecies hybridization that is compatible with random gene loss models and suggests genomic plasticity during WGD in yeast.IMPORTANCE A whole-genome duplication occurred in an ancestor of the baker's yeast Saccharomyces cerevisiae The origins of this complex and multifaceted process, which requires intra- or interspecies hybridization followed by dysfunction of one mating-type (MAT) locus to regain mating competence, has not been thoroughly elucidated. In this study, we provide a mechanism for regaining fertility in an interspecies hybrid, Zygosaccharomyces rouxii The draft genome sequence analysis and mating test showed that the Z. rouxii strain used in this study is an intact interspecies hybrid, suggesting that it is possible to recover fertility regardless of whether cells lose one MAT locus.


Assuntos
Hibridização Genética , Zygosaccharomyces/fisiologia , Diploide , Proteínas Fúngicas/genética , Proteínas Fúngicas/metabolismo , Regulação Fúngica da Expressão Gênica , Genes Fúngicos Tipo Acasalamento , Zygosaccharomyces/genética
8.
Environ Sci Pollut Res Int ; 24(22): 18630-18639, 2017 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-28647878

RESUMO

Cd2+ resistance and bioaccumulation capacity were selected from parental Zygosaccharomyces rouxii (CRZ-0) while maintaining NaCl tolerance using protoplast mutagenesis technology. Ultraviolet-diethyl sulfate (UV-DES) cooperative mutagenesis, followed by preliminary screening and rescreening, was used to select the mutant strain CRZ-9. CRZ-9 grew better than CRZ-0 in YPD medium with 20 or 50 mg L-1 of Cd2+. Scanning electron microscopy observations and flow cytometry tests indicated that CRZ-9 was more effective at eliminating reactive oxygen species (ROS) generated by Cd2+, which led to less cellular structural damage and lower lethality. Furthermore, compared with CRZ-0, CRZ-9 exhibited increased potential for application with higher Cd2+ removal ratio, wider working pH range, and lower biomass dosage in Cd2+ bioaccumulation. The mutant strain CRZ-9 possessed improved Cd2+ resistance and bioaccumulation capacity and therefore is a promising strain to remove Cd2+ from wastewater.


Assuntos
Cádmio/metabolismo , Ecotoxicologia/métodos , Mutagênese , Raios Ultravioleta , Zygosaccharomyces/fisiologia , Cádmio/toxicidade , Espécies Reativas de Oxigênio/metabolismo , Cloreto de Sódio/metabolismo , Ésteres do Ácido Sulfúrico/toxicidade , Purificação da Água , Zygosaccharomyces/efeitos dos fármacos , Zygosaccharomyces/genética , Zygosaccharomyces/efeitos da radiação
9.
Food Microbiol ; 64: 7-14, 2017 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-28213037

RESUMO

Zygosaccharomyces rouxii is the main spoilage yeast of grape juice concentrates. Detection and identification of Z. rouxii during the production of grape juice concentrate is critical to prevent spoilage in the final product. In this work, three grape juice concentrate processing plants were assessed by identifying osmophilic yeasts in juices and surfaces during different stages of a complete production line. Subsequently, molecular typing of Z. rouxii isolates was done to determine the strain distribution of this spoilage yeast. Osmotolerant yeast species, other than Z. rouxii, were mainly recovered from processing plant environments. Z. rouxii was only isolated from surface samples with grape juice remains. Z. rouxii was largely isolated from grape juice samples with some degree of concentration. Storage of grape juice pre-concentrate and concentrate allowed an increase in the Z. rouxii population. A widely distributed dominant molecular Z. rouxii pattern was found in samples from all three processing plants, suggesting resident microbes inside the plant.


Assuntos
Sucos de Frutas e Vegetais/microbiologia , Vitis/microbiologia , Leveduras/isolamento & purificação , Zygosaccharomyces/isolamento & purificação , Contaminação de Alimentos/análise , Microbiologia de Alimentos , Indústria de Processamento de Alimentos , Tipagem Molecular , Técnicas de Tipagem Micológica , Saccharomyces cerevisiae/isolamento & purificação , Saccharomyces cerevisiae/fisiologia , Leveduras/fisiologia , Zygosaccharomyces/genética , Zygosaccharomyces/fisiologia
10.
J Biosci Bioeng ; 123(2): 203-208, 2017 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-27939139

RESUMO

Soy sauce is a Japanese traditional seasoning composed of various constituents that are produced by various microbes during a long-term fermentation process. Due to the complexity of the process, the investigation of the constituent profile during fermentation is difficult. Metabolomics, the comprehensive study of low molecular weight compounds in biological samples, is thought to be a promising strategy for deep understanding of the constituent contribution to food flavor characteristics. Therefore, metabolomics is suitable for the analysis of soy sauce fermentation. Unfortunately, only few and unrefined studies of soy sauce fermentation using metabolomics approach have been reported. Therefore, we investigated changes in low molecular weight hydrophilic and volatile compounds of soy sauce using gas chromatography/mass spectrometry (GC/MS)-based non-targeted metabolic profiling. The data were analyzed by statistical analysis to evaluate influences of yeast and lactic acid bacterium on the constituent profile. Consequently, our results suggested a novel finding that lactic acid bacterium affected the production of several constituents such as cyclotene, furfural, furfuryl alcohol and methional in the soy sauce fermentation process.


Assuntos
Enterococcaceae/fisiologia , Fermentação , Alimentos de Soja/análise , Zygosaccharomyces/fisiologia , Aldeídos/análise , Aldeídos/metabolismo , Ciclopentanos/análise , Ciclopentanos/metabolismo , Enterococcaceae/metabolismo , Furaldeído/análise , Furaldeído/metabolismo , Furanos/análise , Furanos/metabolismo , Cromatografia Gasosa-Espectrometria de Massas , Ácido Láctico/metabolismo , Alimentos de Soja/microbiologia , Zygosaccharomyces/metabolismo
11.
FEMS Yeast Res ; 16(6)2016 09.
Artigo em Inglês | MEDLINE | ID: mdl-27493145

RESUMO

The Zygosaccharomyces rouxii complex comprises three distinct lineages of halotolerant yeasts relevant in food processing and spoilage, such as Z. sapae, Z. rouxii and a mosaic group of allodiploid strains. They manifest plastic genome architecture (variation in karyotype, ploidy level and Na(+)/H(+) antiporter-encoding gene copy number), and exhibit diverse tolerances to salt concentrations. Here, we investigated accumulation of compatible osmolytes and transcriptional regulation of Na(+)/H(+) antiporter-encoding ZrSOD genes during salt exposure in strains representative for the lineages, namely Z. sapae ABT301(T) (low salt tolerant), Z. rouxii CBS 732(T) (middle salt tolerant) and allodiploid strain ATCC 42981 (high salt tolerant). Growth curve modelling in 2 M NaCl-containing media supplemented with or without yeast extract as nitrogen source indicates that moderate salt tolerance of CBS 732(T) mainly depends on nitrogen availability rather than intrinsic inhibitory effects of salt. All the strains produce glycerol and not mannitol under salt stress and use two different glycerol balance strategies. ATCC 42981 produces comparatively more glycerol than Z. sapae and Z. rouxii under standard growth conditions and better retains it intracellularly under salt injuries. Conversely, Z. sapae and Z. rouxii enhance glycerol production under salt stress and intracellularly retain glycerol less efficiently than ATCC 42981. Expression analysis shows that, in diploid Z. sapae and allodiploid ATCC 42981, transcription of gene variants ZrSOD2-22/ZrSOD2 and ZrSOD22 is constitutive and salt unresponsive.


Assuntos
Pressão Osmótica , Cloreto de Sódio/metabolismo , Trocadores de Sódio-Hidrogênio/metabolismo , Estresse Fisiológico , Zygosaccharomyces/efeitos dos fármacos , Zygosaccharomyces/fisiologia , Meios de Cultura/química , Perfilação da Expressão Gênica , Glicerol/metabolismo , Manitol/metabolismo , Trocadores de Sódio-Hidrogênio/genética , Zygosaccharomyces/genética , Zygosaccharomyces/crescimento & desenvolvimento
12.
FEMS Yeast Res ; 16(5)2016 08.
Artigo em Inglês | MEDLINE | ID: mdl-27381983

RESUMO

The ability of Zygosaccharomyces bailii to grow at low pH and in the presence of considerable amounts of weak organic acids, at lethal condition for Saccharomyces cerevisiae, increased the interest in the biotechnological potential of the yeast. To understand the mechanism of tolerance and growth effect of weak acids on Z. bailii, we evaluated the physiological and macromolecular changes of the yeast exposed to sub lethal concentrations of lactic acid. Lactic acid represents one of the important commodity chemical which can be produced by microbial fermentation. We assessed physiological effect of lactic acid by bioreactor fermentation using synthetic media at low pH in the presence of lactic acid. Samples collected from bioreactors were stained with propidium iodide (PI) which revealed that, despite lactic acid negatively influence the growth rate, the number of PI positive cells is similar to that of the control. Moreover, we have performed Fourier Transform Infra-Red (FTIR) microspectroscopy analysis on intact cells of the same samples. This technique has been never applied before to study Z. bailii under this condition. The analyses revealed lactic acid induced macromolecular changes in the overall cellular protein secondary structures, and alterations of cell wall and membrane physico-chemical properties.


Assuntos
Fermentação , Ácido Láctico/metabolismo , Ácido Láctico/toxicidade , Viabilidade Microbiana/efeitos dos fármacos , Estresse Fisiológico , Zygosaccharomyces/efeitos dos fármacos , Zygosaccharomyces/fisiologia , Anaerobiose , Reatores Biológicos/microbiologia , Membrana Celular/química , Membrana Celular/efeitos dos fármacos , Membrana Celular/fisiologia , Parede Celular/química , Parede Celular/efeitos dos fármacos , Parede Celular/fisiologia , Fenômenos Químicos , Meios de Cultura/química , Proteínas Fúngicas/química , Concentração de Íons de Hidrogênio , Propídio/análise , Conformação Proteica , Espectroscopia de Infravermelho com Transformada de Fourier , Coloração e Rotulagem , Zygosaccharomyces/crescimento & desenvolvimento
13.
Mol Microbiol ; 97(3): 541-59, 2015 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-25943012

RESUMO

The accumulation of glycerol is essential for yeast viability upon hyperosmotic stress. Here we show that the osmotolerant yeast Zygosaccharomyces rouxii has two genes, ZrSTL1 and ZrSTL2, encoding transporters mediating the active uptake of glycerol in symport with protons, contributing to cell osmotolerance and intracellular pH homeostasis. The growth of mutants lacking one or both transporters is affected depending on the growth medium, carbon source, strain auxotrophies, osmotic conditions and the presence of external glycerol. These transporters are localised in the plasma membrane, they transport glycerol with similar kinetic parameters and besides their expected involvement in the cell survival of hyperosmotic stress, they surprisingly both contribute to an efficient survival of hypoosmotic shock and to the maintenance of intracellular pH homeostasis under non-stressed conditions. Unlike STL1 in Sa. cerevisiae, the two Z. rouxii STL genes are not repressed by glucose, but their expression and activity are downregulated by fructose and upregulated by non-fermentable carbon sources, with ZrSTL1 being more influenced than ZrSTL2. In summary, both transporters are highly important, though Z. rouxii CBS 732(T) cells do not use external glycerol as a source of carbon.


Assuntos
Glicerol/metabolismo , Osmorregulação , Simportadores/metabolismo , Zygosaccharomyces/fisiologia , Transporte Biológico , Meios de Cultura/química , Deleção de Genes , Regulação Fúngica da Expressão Gênica/efeitos dos fármacos , Concentração de Íons de Hidrogênio , Viabilidade Microbiana , Compostos Orgânicos/metabolismo , Pressão Osmótica , Estresse Fisiológico , Simportadores/genética , Zygosaccharomyces/genética , Zygosaccharomyces/crescimento & desenvolvimento , Zygosaccharomyces/metabolismo
14.
ScientificWorldJournal ; 2014: 135856, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-24977173

RESUMO

The influence of sublethal concentrations of two sanitizers, liquid iodophor and liquid hypochlorite (LH), on the growth rates and toxicity of food-borne pathogenic Escherichia coli strains grown in the presence of spoilage yeast Zygosaccharomyces bailii was assessed. When grown in combination with Z. bailii both E. coli O113 and E. coli O26 exhibited slower growth rates, except when E. coli O113 was grown in combination with Z. bailii at 0.2% LH. The growth rate of Z. bailii was not impacted by the addition of the sanitizers or by communal growth with E. coli strains. LAL and IL-6 results indicated a decrease in toxicity of pure E. coli cultures with comparable profiles for control and sanitizer exposed samples, although the LAL assay proved to be more sensitive. Interestingly, pure cultures of Z. bailii showed increased toxicity measured by LAL and decreased toxicity measured by IL-6. LAL analysis showed a decrease in toxicity of both E. coli strains grown in combination with Z. bailii, while IL-6 analysis of the mixed cultures showed an increase in toxicity. The use of LAL for toxicity determination in a mixed culture overlooks the contribution made by spoilage yeast, thus demonstrating the importance of using the appropriate method for toxicity testing in mixed microbe environments.


Assuntos
Escherichia coli/fisiologia , Microbiologia de Alimentos , Ácido Hipocloroso/administração & dosagem , Iodóforos/administração & dosagem , Lipopolissacarídeos/biossíntese , Consórcios Microbianos/fisiologia , Zygosaccharomyces/fisiologia , Antibacterianos/administração & dosagem , Anti-Infecciosos Locais , Sobrevivência Celular/efeitos dos fármacos , Relação Dose-Resposta a Droga , Escherichia coli/efeitos dos fármacos , Consórcios Microbianos/efeitos dos fármacos , Zygosaccharomyces/efeitos dos fármacos
15.
J Agric Food Chem ; 62(27): 6345-53, 2014 Jul 09.
Artigo em Inglês | MEDLINE | ID: mdl-24956381

RESUMO

In order to provide scientific evidence for the relationship between the traditional usage, stems and leaves of Desmodium caudatum being used for protecting miso from spoilage, and its Japanese name (miso-naoshi), phytochemical study on the stems and leaves of this plant was carried out. Seven new prenylated flavonoids (1-3, 15-18), together with 19 known compounds (4-14, 19-26), were isolated, and the structures of new compounds were elucidated by extensive spectroscopic analyses. The minimum inhibitory concentrations (MICs) of 28 flavonoids, including 17 compounds (1, 2, 4, 5, 7-14, 20-22, 24, 25) isolated in this study and 11 flavonoids (27-37) previously isolated from the roots of this plant, against the film-forming yeast of Zygosaccharomyces rouxii F51 were determined. Fifteen compounds (2, 4, 5, 11, 12, 14, 21, 22, 25, 27, 28, 32-35) inhibited the film-forming growth of Z. rouxii F51 (MIC values, 7.8-62.5 µg/mL), among which 2",2"-dimethylpyran-(5",6":7,8)-5,2'-dihydroxy-4'-methoxy-(2R,3R)-dihydroflavonol (11) demonstrated potent inhibitory activity with an MIC value of 7.8 µg/mL.


Assuntos
Antifúngicos/farmacologia , Biofilmes/efeitos dos fármacos , Fabaceae/química , Flavonoides/farmacologia , Extratos Vegetais/farmacologia , Zygosaccharomyces/efeitos dos fármacos , Zygosaccharomyces/fisiologia , Antifúngicos/química , Flavonoides/química , Extratos Vegetais/química , Folhas de Planta/química , Caules de Planta/química , Prenilação , Zygosaccharomyces/crescimento & desenvolvimento
16.
Methods Mol Biol ; 1152: 63-85, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-24744027

RESUMO

Microorganisms offer a tremendous potential as cell factories, and they are indeed used by humans for centuries for biotransformations. Among them, yeasts combine the advantage of unicellular state with a eukaryotic organization, and, in the era of biorefineries, their biodiversity can offer solutions to specific process constraints. Zygosaccharomyces bailii, an ascomycetales budding yeast, is widely known for its peculiar tolerance to various stresses, among which are organic acids. Despite the possibility to apply with this yeast some of the molecular tools and protocols routinely used to manipulate Saccharomyces cerevisiae, adjustments and optimizations are necessary. Here, we describe in detail protocols for transformation, for target gene disruption or gene integration, and for designing episomal expression plasmids helpful for developing and further studying the yeast Z. bailii.


Assuntos
Engenharia Genética/métodos , Zygosaccharomyces/genética , Zygosaccharomyces/fisiologia , Acetatos/farmacologia , Ácidos/farmacologia , Técnicas de Cultura , DNA de Cadeia Simples/genética , Eletroporação , Deleção de Genes , Plasmídeos/genética , Transformação Genética , Zygosaccharomyces/efeitos dos fármacos , Zygosaccharomyces/crescimento & desenvolvimento
17.
FEMS Yeast Res ; 14(4): 586-600, 2014 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-24533625

RESUMO

Zygosaccharomyces rouxii complex comprises three yeasts clusters sourced from sugar- and salt-rich environments: haploid Zygosaccharomyces rouxii, diploid Zygosaccharomyces sapae and allodiploid/aneuploid strains of uncertain taxonomic affiliations. These yeasts have been characterized with respect to gene copy number variation, karyotype variability and change in ploidy, but functional diversity in stress responses has not been explored yet. Here, we quantitatively analysed the stress response variation in seven strains of the Z. rouxii complex by modelling growth variables via model and model-free fitting methods. Based on the spline fit as most reliable modelling method, we resolved different interstrain responses to 15 environmental perturbations. Compared with Z. rouxii CBS 732(T) and Z. sapae strains ABT301(T) and ABT601, allodiploid strain ATCC 42981 and aneuploid strains CBS 4837 and CBS 4838 displayed higher multistress resistance and better performance in glycerol respiration even in the presence of copper. µ-based logarithmic phenotypic index highlighted that ABT601 is a slow-growing strain insensitive to stress, whereas ABT301(T) grows fast on rich medium and is sensitive to suboptimal conditions. Overall, the differences in stress response could imply different adaptation mechanisms to sugar- and salt-rich niches. The obtained phenotypic profiling contributes to provide quantitative insights for elucidating the adaptive mechanisms to stress in halo- and osmo-tolerant Zygosaccharomyces yeasts.


Assuntos
Fenótipo , Estresse Fisiológico , Zygosaccharomyces/fisiologia , Cobre/metabolismo , Glicerol/metabolismo , Modelos Teóricos , Zygosaccharomyces/efeitos dos fármacos , Zygosaccharomyces/crescimento & desenvolvimento , Zygosaccharomyces/metabolismo
18.
PLoS One ; 8(9): e73936, 2013.
Artigo em Inglês | MEDLINE | ID: mdl-24023914

RESUMO

When using microorganisms as cell factories in the production of bio-based fuels or chemicals from lignocellulosic hydrolysate, inhibitory concentrations of acetic acid, released from the biomass, reduce the production rate. The undissociated form of acetic acid enters the cell by passive diffusion across the lipid bilayer, mediating toxic effects inside the cell. In order to elucidate a possible link between lipid composition and acetic acid stress, the present study presents detailed lipidomic profiling of the major lipid species found in the plasma membrane, including glycerophospholipids, sphingolipids and sterols, in Saccharomyces cerevisiae (CEN.PK 113_7D) and Zygosaccharomyces bailii (CBS7555) cultured with acetic acid. Detailed physiological characterization of the response of the two yeasts to acetic acid has also been performed in aerobic batch cultivations using bioreactors. Physiological characterization revealed, as expected, that Z. bailii is more tolerant to acetic acid than S. cerevisiae. Z. bailii grew at acetic acid concentrations above 24 g L(-1), while limited growth of S. cerevisiae was observed after 11 h when cultured with only 12 g L(-1) acetic acid. Detailed lipidomic profiling using electrospray ionization, multiple-reaction-monitoring mass spectrometry (ESI-MRM-MS) showed remarkable changes in the glycerophospholipid composition of Z. bailii, including an increase in saturated glycerophospholipids and considerable increases in complex sphingolipids in both S. cerevisiae (IPC 6.2×, MIPC 9.1×, M(IP)2C 2.2×) and Z. bailii (IPC 4.9×, MIPC 2.7×, M(IP)2C 2.7×), when cultured with acetic acid. In addition, the basal level of complex sphingolipids was significantly higher in Z. bailii than in S. cerevisiae, further emphasizing the proposed link between lipid saturation, high sphingolipid levels and acetic acid tolerance. The results also suggest that acetic acid tolerance is associated with the ability of a given strain to generate large rearrangements in its lipid profile.


Assuntos
Ácido Acético/farmacologia , Metabolismo dos Lipídeos/efeitos dos fármacos , Saccharomyces cerevisiae/efeitos dos fármacos , Saccharomyces cerevisiae/metabolismo , Estresse Fisiológico/efeitos dos fármacos , Zygosaccharomyces/efeitos dos fármacos , Zygosaccharomyces/metabolismo , Adaptação Fisiológica/efeitos dos fármacos , Relação Dose-Resposta a Droga , Saccharomyces cerevisiae/fisiologia , Especificidade da Espécie , Zygosaccharomyces/fisiologia
19.
Genetics ; 195(2): 393-405, 2013 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-23893487

RESUMO

Copy number variations (CNVs) contribute to the adaptation process in two possible ways. First, they may have a direct role, in which a certain number of copies often provide a selective advantage. Second, CNVs can also indirectly contribute to adaptation because a higher copy number increases the so-called "mutational target size." In this study, we show that the copy number amplification of FLO11D in the osmotolerant yeast Zygosaccharomyces rouxii promotes its further adaptation to a flor-formative environment, such as osmostress static culture conditions. We demonstrate that a gene, which was identified as FLO11D, is responsible for flor formation and that its expression is induced by osmostress under glucose-free conditions, which confer unique characteristics to Z. rouxii, such as osmostress-dependent flor formation. This organism possesses zero to three copies of FLO11D, and it appears likely that the FLO11D copy number increased in a branch of the Z. rouxii tree. The cellular hydrophobicity correlates with the FLO11D copy number, and the strain with a higher copy number of FLO11D exhibits a fitness advantage compared to a reference strain under osmostress static culture conditions. Our data indicate that the FLO gene-related system in Z. rouxii has evolved remarkably to adapt to osmostress environments.


Assuntos
Variações do Número de Cópias de DNA/genética , Glicoproteínas de Membrana/genética , Pressão Osmótica , Proteínas de Saccharomyces cerevisiae/genética , Zygosaccharomyces/genética , Sequência de Aminoácidos , Biofilmes/crescimento & desenvolvimento , Evolução Molecular , Regulação Fúngica da Expressão Gênica , Mutação , Saccharomyces cerevisiae/genética , Saccharomyces cerevisiae/fisiologia , Zygosaccharomyces/fisiologia
20.
Bioresour Technol ; 143: 46-52, 2013 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-23774294

RESUMO

Application of microorganisms as bioremediators for heavy metal removal in high salt environment is usually restricted by high salt concentrations. The effect of NaCl on the heavy metal tolerance and bioaccumulation of Zygosaccharomyces rouxii and Saccharomyces cerevisiae was investigated. For both yeasts, NaCl improved the cadmium and zinc tolerance, reduced the copper tolerance, and showed no obvious effect on the lead and iron tolerance. The bioaccumulation capacities of copper, zinc, and iron increased but the cadmium bioaccumulation capacities decreased after the addition of NaCl. NaCl obviously affected the amount of heavy metals removed intracellularly and on the cell surface. The heavy metal removal was not overwhelmingly inhibited by elevated NaCl concentrations, especially for Z. rouxii, and in some cases NaCl improved their removal ability. The salt-tolerant Z. rouxii that showed more powerful heavy metal tolerance and removal ability might be more suitable for heavy metal removal in high salt environment.


Assuntos
Adaptação Fisiológica , Metais Pesados/farmacologia , Saccharomyces cerevisiae/efeitos dos fármacos , Cloreto de Sódio/farmacologia , Zygosaccharomyces/efeitos dos fármacos , Metais Pesados/metabolismo , Saccharomyces cerevisiae/metabolismo , Saccharomyces cerevisiae/fisiologia , Zygosaccharomyces/metabolismo , Zygosaccharomyces/fisiologia
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