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1.
PLoS Genet ; 17(11): e1009872, 2021 11.
Artigo em Inglês | MEDLINE | ID: mdl-34762651

RESUMO

Different species can find convergent solutions to adapt their genome to the same evolutionary constraints, although functional convergence promoted by chromosomal rearrangements in different species has not previously been found. In this work, we discovered that two domesticated yeast species, Saccharomyces cerevisiae, and Saccharomyces uvarum, acquired chromosomal rearrangements to convergently adapt to the presence of sulfite in fermentation environments. We found two new heterologous chromosomal translocations in fermentative strains of S. uvarum at the SSU1 locus, involved in sulfite resistance, an antimicrobial additive widely used in food production. These are convergent events that share similarities with other SSU1 locus chromosomal translocations previously described in domesticated S. cerevisiae strains. In S. uvarum, the newly described VIIXVI and XIXVI chromosomal translocations generate an overexpression of the SSU1 gene and confer increased sulfite resistance. This study highlights the relevance of chromosomal rearrangements to promote the adaptation of yeast to anthropic environments.


Assuntos
Adaptação Biológica/genética , Anti-Infecciosos/metabolismo , Fermentação , Conservantes de Alimentos/metabolismo , Saccharomyces cerevisiae/fisiologia , Saccharomyces/fisiologia , Sulfitos/metabolismo , Proteínas de Transporte de Ânions/genética , Cromossomos Fúngicos , Humanos , Filogenia , Regiões Promotoras Genéticas , Saccharomyces/genética , Saccharomyces/metabolismo , Saccharomyces cerevisiae/genética , Saccharomyces cerevisiae/metabolismo , Proteínas de Saccharomyces cerevisiae/genética , Translocação Genética
2.
BMC Biol ; 21(1): 102, 2023 05 08.
Artigo em Inglês | MEDLINE | ID: mdl-37158891

RESUMO

BACKGROUND: Horizontal gene transfer (HGT) is an evolutionary mechanism of adaptive importance, which has been deeply studied in wine S. cerevisiae strains, where those acquired genes conferred improved traits related to both transport and metabolism of the nutrients present in the grape must. However, little is known about HGT events that occurred in wild Saccharomyces yeasts and how they determine their phenotypes. RESULTS: Through a comparative genomic approach among Saccharomyces species, we detected a subtelomeric segment present in the S. uvarum, S. kudriavzevii, and S. eubayanus species, belonging to the first species to diverge in the Saccharomyces genus, but absent in the other Saccharomyces species. The segment contains three genes, two of which were characterized, named DGD1 and DGD2. DGD1 encodes dialkylglicine decarboxylase, whose specific substrate is the non-proteinogenic amino acid 2-aminoisobutyric acid (AIB), a rare amino acid present in some antimicrobial peptides of fungal origin. DGD2 encodes putative zinc finger transcription factor, which is essential to induce the AIB-dependent expression of DGD1. Phylogenetic analysis showed that DGD1 and DGD2 are closely related to two adjacent genes present in Zygosaccharomyces. CONCLUSIONS: The presented results show evidence of an early HGT event conferring new traits to the ancestor of the Saccharomyces genus that could be lost in the evolutionary more recent Saccharomyces species, perhaps due to loss of function during the colonization of new habitats.


Assuntos
Saccharomyces , Transaminases , Saccharomyces/genética , Transferência Genética Horizontal , Filogenia , Saccharomyces cerevisiae , Aminoácidos , Ácidos Aminoisobutíricos
3.
Int Microbiol ; 26(2): 361-370, 2023 May.
Artigo em Inglês | MEDLINE | ID: mdl-36370206

RESUMO

Kefir is a fermented probiotic drink obtained by placing kefir granules in a suitable substrate. The kefir granules are a consortium of bacteria and yeasts embedded in a exopolysaccharide matrix. The aim of this research was the isolation and identification of yeasts from kefir of different origin, the evaluation of their antifungal capacity against Aspergillus spp., and the characterization of virulence related traits. Using RFLP of ITS1/ITS4 region, D1/D2 region sequencing, and RAPD techniques, 20 kefir isolates were identified as Geotrichum candidum, Pichia kudriavzevii, Pichia membranifaciens, Saccharomyces cerevisiae, and Candida ethanolica. Their antifungal capacity was evaluated by their conidia germination reduction, which allowed the selection of eight isolates with high to moderate conidia germination reduction against Aspergillus flavus and Aspergillus parasiticus. Furthermore, these selected isolates showed growth inhibition on contact in the dual culture assay for both Aspergillus species and 3 of them-belonging to S. cerevisiae and P. kudriavzevii species-generated volatile organic compounds which significantly affected the growth of both fungi. For the evaluation of virulence-related traits, growth at high temperatures, enzymatic activities, and the adhesion to Caco-2 cells were analyzed. The isolates did not present more than one positive virulence-related trait simultaneously. In particular, it is important to highlight that the adhesion capacity to the model of intestinal barrier was extremely low for all of them. According to the results obtained, further studies would be of interest for the possible use of these promising yeasts as biocontrol agents against fungi in food.


Assuntos
Antifúngicos , Kefir , Humanos , Antifúngicos/farmacologia , Saccharomyces cerevisiae/genética , Técnica de Amplificação ao Acaso de DNA Polimórfico , Células CACO-2 , Leveduras/genética , Aspergillus
4.
Crit Rev Food Sci Nutr ; : 1-16, 2022 Oct 12.
Artigo em Inglês | MEDLINE | ID: mdl-36222026

RESUMO

Food consumption of healthier products has become an essential trend in the food sector. This is also the case in beer, a biochemical process of transformation performed by yeast cells. More and more studies proclaim the need to reduce ethanol content in alcoholic drinks, certainly the most important health issue of beer consumption. In this review we gather key health issues related to beer consumption and the last advances regarding the use of yeast to attenuate those health problems. Furthermore, we have included the latest findings about the general positive impact of yeast in health as a consequence of its ability to biotransform polyphenolic compounds present in the wort, producing healthy compounds as hydroxytyrosol or melatonin, and its ability to perform as a probiotic driver. Besides, a group of population with chronic diseases as diabetes or celiac disease could take advantage of low carbohydrate or gluten-free beers, respectively. The role of yeast in beer production has been traditionally associated to its fermentative power. But here we have found a change in this dogma in the last years toward yeasts being a main driver to enhance healthy aspects of beer. The key findings are discussed and possible future directions are proposed.

5.
Environ Microbiol ; 23(6): 3059-3076, 2021 06.
Artigo em Inglês | MEDLINE | ID: mdl-33848053

RESUMO

Saccharomyces cerevisiae, a widespread yeast present both in the wild and in fermentative processes, like winemaking. During the colonization of these human-associated fermentative environments, certain strains of S. cerevisiae acquired differential adaptive traits that enhanced their physiological properties to cope with the challenges imposed by these new ecological niches. The advent of omics technologies allowed unveiling some details of the molecular bases responsible for the peculiar traits of S. cerevisiae wine strains. However, the metabolic diversity within yeasts remained poorly explored, in particular that existing between wine and wild strains of S. cerevisiae. For this purpose, we performed a dual transcriptomic and metabolomic comparative analysis between a wild and a wine S. cerevisiae strains during wine fermentations performed at high and low temperatures. By using this approach, we could correlate the differential expression of genes involved in metabolic pathways, such as sulfur, arginine and thiamine metabolisms, with differences in the amounts of key metabolites that can explain some important differences in the fermentation performance between the wine and wild strains.


Assuntos
Vinho , Fermentação , Humanos , Metabolômica , Fenótipo , Saccharomyces cerevisiae/genética , Vinho/análise
6.
Environ Microbiol ; 22(9): 3700-3721, 2020 09.
Artigo em Inglês | MEDLINE | ID: mdl-32573081

RESUMO

The monitoring of fermentation at low temperatures (12-15°C) is a current practice in the winery for retention and enhancement of the flavour volatile content of wines. Among Saccharomyces species, Saccharomyces uvarum and Saccharomyces kudriavzevii have revealed interesting industrial properties, including better adaptation at low temperatures. To gather deeper knowledge of the fermentative metabolism at a low temperature of these species together with S. cerevisiae, we performed a comparative metabolomic analysis using four representative strains. We used batch cultures to obtain an exhaustive and dynamic image of the metabolome of strains passing through the sequential stresses related to the winemaking environment. A great variety of intra- and extracellular metabolites (>500 compounds) were quantified across fermentation using distinct chromatographic methods. Besides a global decrease in the lipid composition of the four strains when they entered into the stationary phase, we reported some strain-specific high magnitude changes. Examples of these differences included divergent patterns of production of short-chain fatty acids and erythritol in the S. uvarum strain. Strains also differed in expression for aromatic amino acid biosynthesis and sulphur metabolism, including the glutathione pathway. These data will allow us to refine and obtain the most value of fermentations with this alternative Saccharomyces species.


Assuntos
Saccharomyces cerevisiae/metabolismo , Saccharomyces/metabolismo , Vinho , Aminoácidos/metabolismo , Fermentação , Glutationa/metabolismo , Metabolismo dos Lipídeos , Metaboloma , Enxofre/metabolismo , Temperatura
7.
Food Microbiol ; 90: 103484, 2020 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-32336360

RESUMO

In this study, we presented the first metabolome time course analysis performed among a set of S. uvarum, S. kudriavzevii and S. cerevisiae strains under winemaking conditions. Extracellular and intracellular metabolites, as well as physiological parameters of yeast cells, were monitored along the process to find evidence of different metabolic strategies among species to perform alcoholic fermentation. A thorough inspection of time trends revealed several differences in utilization or accumulation of fermentation by-products. We confirmed the ability of S. uvarum and S. kudriavzevii strains to produce higher amounts of glycerol, succinate or some fusel alcohols and their corresponding esters. We also reported differences in the yields of less common fermentative by-products involved in redox homeostasis, namely 2,3 butanediol and erythritol. 2,3 butanediol yield was higher in must ferment with cryophilic strains and erythritol, a pentose phosphate pathway derivative, was particularly overproduced by S. uvarum strains. Contrary to S. cerevisiae, a singular production-consumption rate of acetate was also observed in S. uvarum and S. kudriavzevii fermentations. Since acetate is a precursor for acetyl-CoA production which is involved in the biosynthesis of membrane lipids, cryophilc strains might take advantage of extracellular acetate to remodel cell membrane as ethanol content increased during fermentation.


Assuntos
Fermentação , Saccharomyces cerevisiae/metabolismo , Saccharomyces/metabolismo , Vinho/microbiologia , Acetatos/metabolismo , Álcoois/metabolismo , Eritritol/metabolismo , Metaboloma , Oxirredução , Prolina/metabolismo , Saccharomyces/classificação , Fatores de Tempo
8.
Environ Microbiol ; 21(5): 1627-1644, 2019 05.
Artigo em Inglês | MEDLINE | ID: mdl-30672093

RESUMO

Grape must is a sugar-rich habitat for a complex microbiota which is replaced by Saccharomyces cerevisiae strains during the first fermentation stages. Interest on yeast competitive interactions has recently been propelled due to the use of alternative yeasts in the wine industry to respond to new market demands. The main issue resides in the persistence of these yeasts due to the specific competitive activity of S. cerevisiae. To gather deeper knowledge of the molecular mechanisms involved, we performed a comparative transcriptomic analysis during fermentation carried out by a wine S. cerevisiae strain and a strain representative of the cryophilic S. kudriavzevii, which exhibits high genetic and physiological similarities to S. cerevisiae, but also differences of biotechnological interest. In this study, we report that transcriptomic response to the presence of a competitor is stronger in S. cerevisiae than in S. kudriavzevii. Our results demonstrate that a wine S. cerevisiae industrial strain accelerates nutrient uptake and utilization to outcompete the co-inoculated yeast, and that this process requires cell-to-cell contact to occur. Finally, we propose that this competitive phenotype evolved recently, during the adaptation of S. cerevisiae to man-manipulated fermentative environments, since a non-wine S. cerevisiae strain, isolated from a North American oak, showed a remarkable low response to competition.


Assuntos
Saccharomyces cerevisiae/metabolismo , Saccharomyces/metabolismo , Vitis/microbiologia , Vinho/microbiologia , Adaptação Fisiológica , Fermentação , Nutrientes/metabolismo , Fenótipo , Saccharomyces/genética , Saccharomyces cerevisiae/genética , Vinho/análise
9.
Yeast ; 35(1): 51-69, 2018 01.
Artigo em Inglês | MEDLINE | ID: mdl-29027262

RESUMO

Companies based on alcoholic fermentation products, such as wine, beer and biofuels, use yeasts to make their products. Each industrial process utilizes different media conditions, which differ in sugar content, the presence of inhibitors and fermentation temperature. Saccharomyces cerevisiae has traditionally been the main yeast responsible for most fermentation processes. However, the market is changing due to consumer demand and external factors such as climate change. Some processes, such as biofuel production or winemaking, require new yeasts to solve specific challenges, especially those associated with sustainability, novel flavours and altered alcohol content. One of the proposed solutions is the application of yeast hybrids. The lager beer market has been dominated by S. cerevisiae × S. eubayanus hybrids. However, several less thoroughly studied hybrids have been isolated from other diverse industrial processes. Here we focus on S. cerevisiae × S. kudriavzevii hybrids, which have been isolated from diverse industrial conditions that include wine, ale beer, cider and dietary supplements. Emerging data suggest an extended and complex story of adaptation of these hybrids to traditional industrial conditions. S. cerevisiae × S. kudriavzevii hybrids are also being explored for new industrial applications, such as biofuels. This review describes the past, present and future of S. cerevisiae × S. kudriavzevii hybrids. Copyright © 2017 John Wiley & Sons, Ltd.


Assuntos
Hibridização Genética , Saccharomyces/genética , Biocombustíveis , Fermentação , Indústria Alimentícia
10.
Crit Rev Food Sci Nutr ; 58(11): 1780-1790, 2018 Jul 24.
Artigo em Inglês | MEDLINE | ID: mdl-28362111

RESUMO

Wine fermentation has not significantly changed since ancient times and the most traditional aspects are seen by the market as elements that uplift wine nuances and quality. In recent years, new trends have emerged from the sector in line with consumer preferences, and due to the effects of global climate change on grape ripening. In the first cases, the consumers are looking for wines with less ethanol and fruitier aromas and in the second cases the wineries want to reduce the wine alcohol levels and/or astringency. New yeast starters of alternative Saccharomyces species and their hybrids can help to solve some problems that wineries face. In this article we review several physiological and genetic aspects of S. uvarum and S. kudriavzevii and the hybrids, which are especially relevant during the winemaking process, such as their good fermentative capabilities at low temperatures, resulting in wines with lower alcohol and higher glycerol amounts.


Assuntos
Saccharomyces/metabolismo , Vinho/microbiologia , Adaptação Fisiológica , Temperatura Baixa , Etanol/análise , Fermentação , Manipulação de Alimentos , Glicerol/análise , Estrutura Molecular , Saccharomyces/classificação , Saccharomyces cerevisiae/metabolismo , Olfato , Paladar , Vitis
11.
Microb Cell Fact ; 15: 51, 2016 Mar 12.
Artigo em Inglês | MEDLINE | ID: mdl-26971319

RESUMO

BACKGROUND: The yeast amino acid catabolism plays an important role in flavour generation since higher alcohols and acetate esters, amino acid catabolism end products, are key components of overall flavour and aroma in fermented products. Comparative studies have shown that other Saccharomyces species, such as S. kudriavzevii, differ during the production of aroma-active higher alcohols and their esters compared to S. cerevisiae. RESULTS: In this study, we performed a comparative analysis of the enzymes involved in the amino acid catabolism of S. kudriavzevii with their potential to improve the flavour production capacity of S. cerevisiae. In silico screening, based on the severity of amino acid substitutions evaluated by Grantham matrix, revealed four candidates, of which S. kudriavzevii Aro10p (SkAro10p) had the highest score. The analysis of higher alcohols and esters produced by S. cerevisiae then revealed enhanced formation of isobutanol, isoamyl alcohol and their esters when endogenous ARO10 was replaced with ARO10 from S. kudriavzevii. Also, significant differences in the aroma profile were found in fermentations of synthetic wine must. Substrate specificities of SkAro10p were compared with those of S. cerevisiae Aro10p (ScAro10p) by their expression in a 2-keto acid decarboxylase-null S. cerevisiae strain. Unlike the cell extracts with expressed ScAro10p which showed greater activity for phenylpyruvate, which suggests this phenylalanine-derivative to be the preferred substrate, the decarboxylation activities measured in the cell extracts with SkAro10p ranged with all the tested substrates at the same level. The activities of SkAro10p towards substrates (except phenylpyruvate) were higher than of those for ScAro10p. CONCLUSIONS: The results indicate that the amino acid variations observed between the orthologues decarboxylases encoded by SkARO10 and ScARO10 could be the reason for the distinct enzyme properties, which possibly lead to the enhanced production of several flavour compounds. The knowledge on the important enzyme involved in higher alcohols biosynthesis by S. kudriavzevii could be of scientific as well as of applied interest.


Assuntos
Carboxiliases/genética , Carboxiliases/metabolismo , Aromatizantes/metabolismo , Proteínas de Saccharomyces cerevisiae/genética , Proteínas de Saccharomyces cerevisiae/metabolismo , Saccharomyces , Álcoois/metabolismo , Clonagem Molecular , Descarboxilação/genética , Ésteres/metabolismo , Fermentação/genética , Regulação Fúngica da Expressão Gênica , Saccharomyces/enzimologia , Saccharomyces/genética , Saccharomyces/metabolismo , Proteínas de Saccharomyces cerevisiae/isolamento & purificação , Especificidade por Substrato , Vinho
12.
Microb Cell Fact ; 14: 100, 2015 Jul 09.
Artigo em Inglês | MEDLINE | ID: mdl-26156706

RESUMO

BACKGROUND: Cold stress reduces microbial growth and metabolism being relevant in industrial processes like wine making and brewing. Knowledge on the cold transcriptional response of Saccharomyces cerevisiae suggests the need of a proper redox balance. Nevertheless, there are no direct evidence of the links between NAD(P) levels and cold growth and how engineering of enzymatic reactions requiring NAD(P) may be used to modify the performance of industrial strains at low temperature. RESULTS: Recombinant strains of S. cerevisiae modified for increased NADPH- and NADH-dependent Gdh1 and Gdh2 activity were tested for growth at low temperature. A high-copy number of the GDH2-encoded glutamate dehydrogenase gene stimulated growth at 15°C, while overexpression of GDH1 had detrimental effects, a difference likely caused by cofactor preferences. Indeed, neither the Trp(-) character of the tested strains, which could affect the synthesis of NAD(P), nor changes in oxidative stress susceptibility by overexpression of GDH1 and GDH2 account for the observed phenotypes. However, increased or reduced NADPH availability by knock-out or overexpression of GRE3, the NADPH-dependent aldose reductase gene, eliminated or exacerbated the cold-growth defect observed in YEpGDH1 cells. We also demonstrated that decreased capacity of glycerol production impairs growth at 15 but not at 30°C and that 15°C-grown baker's yeast cells display higher fermentative capacity than those cultivated at 30°C. Thus, increasing NADH oxidation by overexpression of GDH2 would help to avoid perturbations in the redox metabolism induced by a higher fermentative/oxidative balance at low temperature. Finally, it is shown that overexpression of GDH2 increases notably the cold growth in the wine yeast strain QA23 in both standard growth medium and synthetic grape must. CONCLUSIONS: Redox constraints limit the growth of S. cerevisiae at temperatures below the optimal. An adequate supply of NAD(P) precursors as well as a proper level of reducing equivalents in the form of NADPH are required for cold growth. However, a major limitation is the increased need of oxidation of NADH to NAD(+) at low temperature. In this scenario, our results identify the ammonium assimilation pathway as a target for the genetic improvement of cold growth in industrial strains.


Assuntos
Glutamato Desidrogenase/genética , NADP/metabolismo , Proteínas de Saccharomyces cerevisiae/genética , Saccharomyces cerevisiae/metabolismo , Glutamato Desidrogenase/metabolismo , Engenharia Metabólica , Oxirredução , Saccharomyces cerevisiae/enzimologia , Saccharomyces cerevisiae/genética , Saccharomyces cerevisiae/crescimento & desenvolvimento , Proteínas de Saccharomyces cerevisiae/metabolismo
13.
BMC Genomics ; 15: 432, 2014 Jun 04.
Artigo em Inglês | MEDLINE | ID: mdl-24898014

RESUMO

BACKGROUND: Comparative transcriptomics and functional studies of different Saccharomyces species have opened up the possibility of studying and understanding new yeast abilities. This is the case of yeast adaptation to stress, in particular the cold stress response, which is especially relevant for the food industry. Since the species Saccharomyces kudriavzevii is adapted to grow at low temperatures, it has been suggested that it contains physiological adaptations that allow it to rapidly and efficiently acclimatise after cold shock. RESULTS: In this work, we aimed to provide new insights into the molecular basis determining this better cold adaptation of S. kudriavzevii strains. To this end, we have compared S. cerevisiae and S. kudriavzevii transcriptome after yeast adapted to cold shock. The results showed that both yeast mainly activated the genes related to translation machinery by comparing 12°C with 28°C, but the S. kudriavzevii response was stronger, showing an increased expression of dozens of genes involved in protein synthesis. This suggested enhanced translation efficiency at low temperatures, which was confirmed when we observed increased resistance to translation inhibitor paromomycin. Finally, 35S-methionine incorporation assays confirmed the increased S. kudriavzevii translation rate after cold shock. CONCLUSIONS: This work confirms that S. kudriavzevii is able to grow at low temperatures, an interesting ability for different industrial applications. We propose that this adaptation is based on its enhanced ability to initiate a quick, efficient translation of crucial genes in cold adaptation among others, a mechanism that has been suggested for other microorganisms.


Assuntos
Genes Bacterianos , Saccharomyces/crescimento & desenvolvimento , Saccharomyces/genética , Adaptação Fisiológica , Temperatura Baixa , Regulação Bacteriana da Expressão Gênica/efeitos dos fármacos , Genes Bacterianos/efeitos dos fármacos , Paromomicina/farmacologia , Saccharomyces/classificação , Transcriptoma
14.
Int J Food Microbiol ; 399: 110254, 2023 Aug 16.
Artigo em Inglês | MEDLINE | ID: mdl-37244227

RESUMO

The increasing demand for more flavored and complex beers encourages the investigation of novel and non-conventional yeasts with the ability to provide a combination of bioflavoring and low ethanol yields. The present study identified 22 yeasts isolated from different brewing sources, including the fermentation by-products known as yeast sludges, and characterized a selection of strains to find the more suitable for the aforementioned aims. HPLC and GC-FID analysis of its brewing products were performed. The most promising results were obtained with the non-conventional yeasts Pichia kudriavzevii MBELGA61 and Meyerozyma guilliermondii MUS122. The former, isolated from a Belgian wheat beer sludge, was capable of growing in wort (17.0°Bx., 20 °C) with very low ethanol yields (1.19 % v/v). Besides, upon mixed fermentations with Saccharomyces cerevisiae, was suitable to produce volatile compounds such as ethyl acetate, 2-phenyl ethanol and isoamyl alcohol, with characteristic fruity notes. M. guilliermondii MUS122, isolated from a golden ale beer sludge, partially attenuated the wort with low production of ethanol and biomass. In addition, provided some fruity and floral nuances to the aroma profile of mixed fermentations with brewer's yeast. The results suggest that these strains favor the development of more fruity-flowery aroma profiles in beers. Furthermore, they are suitable for use in mixed fermentations with Saccharomyces brewer's strains, although the ethanol level did not decrease significantly.


Assuntos
Cerveja , Esgotos , Fermentação , Cerveja/análise , Leveduras , Saccharomyces cerevisiae , Etanol/análise
15.
Sci Rep ; 13(1): 10435, 2023 06 27.
Artigo em Inglês | MEDLINE | ID: mdl-37369738

RESUMO

Fungal infections are less studied than viral or bacterial infections and often more difficult to treat. Saccharomyces cerevisiae is usually identified as an innocuous human-friendly yeast; however, this yeast can be responsible for infections mainly in immunosuppressed individuals. S. cerevisiae is a relevant organism widely used in the food industry. Therefore, the study of food yeasts as the source of clinical infection is becoming a pivotal question for food safety. In this study, we demonstrate that S. cerevisiae strains cause infections to spread mostly from food environments. Phylogenetic analysis, genome structure analysis, and phenotypic characterization showed that the key sources of the infective strains are food products, such as bread and probiotic supplements. We observed that the adaptation to host infection can drive important phenotypic and genomic changes in these strains that could be good markers to determine the source of infection. These conclusions add pivotal evidence to reinforce the need for surveillance of food-related S. cerevisiae strains as potential opportunistic pathogens.


Assuntos
Probióticos , Saccharomyces cerevisiae , Humanos , Saccharomyces cerevisiae/genética , Filogenia , Genômica , Suplementos Nutricionais
16.
BMC Genomics ; 13: 419, 2012 Aug 23.
Artigo em Inglês | MEDLINE | ID: mdl-22916735

RESUMO

BACKGROUND: In recent years an increasing number of yeast infections in humans have been related to certain clinical isolates of Saccharomyces cerevisiae. Some clinical strains showed in vivo and in vitro virulence traits and were able to cause death in mice whereas other clinical strains were avirulent. RESULTS: In this work, we studied the transcriptional profiles of two S. cerevisiae clinical strains showing virulent traits and two control non-virulent strains during a blood incubation model and detected a specific transcriptional response of clinical strains. This response involves an mRNA levels increase of amino acid biosynthesis genes and especially oxidative stress related genes. We observed that the clinical strains were more resistant to reactive oxygen species in vitro. In addition, blood survival of clinical isolates was high, reaching similar levels to pathogenic Candida albicans strain. Furthermore, a virulent strain mutant in the transcription factor Yap1p, unable to grow in oxidative stress conditions, presented decreased survival levels in human blood compared with the wild type or YAP1 reconstituted strain. CONCLUSIONS: Our data suggest that this enhanced oxidative stress response in virulent clinical isolates, presumably induced in response to oxidative burst from host defense cells, is important to increase survival in human blood and can help to infect and even produce death in mice models.


Assuntos
Sangue/microbiologia , Estresse Oxidativo , Saccharomyces cerevisiae/genética , Saccharomyces cerevisiae/patogenicidade , Transcriptoma , Aminoácidos/biossíntese , Regulação Fúngica da Expressão Gênica , Humanos , RNA Fúngico/metabolismo , RNA Mensageiro/metabolismo , Espécies Reativas de Oxigênio/metabolismo , Saccharomyces cerevisiae/metabolismo , Proteínas de Saccharomyces cerevisiae/genética , Fatores de Transcrição/genética , Virulência
17.
Microb Cell Fact ; 11: 4, 2012 Jan 09.
Artigo em Inglês | MEDLINE | ID: mdl-22230188

RESUMO

BACKGROUND: In the yeast biomass production process, protein carbonylation has severe adverse effects since it diminishes biomass yield and profitability of industrial production plants. However, this significant detriment of yeast performance can be alleviated by increasing thioredoxins levels. Thioredoxins are important antioxidant defenses implicated in many functions in cells, and their primordial functions include scavenging of reactive oxygen species that produce dramatic and irreversible alterations such as protein carbonylation. RESULTS: In this work we have found several proteins specifically protected by yeast Thioredoxin 2 (Trx2p). Bidimensional electrophoresis and carbonylated protein identification from TRX-deficient and TRX-overexpressing cells revealed that glycolysis and fermentation-related proteins are specific targets of Trx2p protection. Indeed, the TRX2 overexpressing strain presented increased activity of the central carbon metabolism enzymes. Interestingly, Trx2p specifically preserved alcohol dehydrogenase I (Adh1p) from carbonylation, decreased oligomer aggregates and increased its enzymatic activity. CONCLUSIONS: The identified proteins suggest that the fermentative capacity detriment observed under industrial conditions in T73 wine commercial strain results from the oxidative carbonylation of specific glycolytic and fermentation enzymes. Indeed, increased thioredoxin levels enhance the performance of key fermentation enzymes such as Adh1p, which consequently increases fermentative capacity.


Assuntos
Biomassa , Carbonilação Proteica , Proteínas de Saccharomyces cerevisiae/metabolismo , Saccharomyces cerevisiae/metabolismo , Tiorredoxinas/genética , Álcool Desidrogenase/metabolismo , Fermentação , Glicólise , Oxirredução , Estresse Oxidativo , Engenharia de Proteínas , Saccharomyces cerevisiae/enzimologia , Saccharomyces cerevisiae/genética , Proteínas de Saccharomyces cerevisiae/genética , Tiorredoxinas/metabolismo
18.
Appl Microbiol Biotechnol ; 94(3): 773-87, 2012 May.
Artigo em Inglês | MEDLINE | ID: mdl-22223102

RESUMO

In the industrial yeast biomass production process, cells undergo an oxidative and other stresses which worsen the quality of the produced biomass. The overexpression of the thioredoxin codifying gene TRX2 in a wine Saccharomyces cerevisiae strain increases resistance to oxidative stress and industrial biomass production yield. We observed that variations in the TRX2 gene dose in wine yeast strains are relevant to determine the fermentative capacity throughout the industrial biomass production process. So, we studied the molecular changes using a transcriptomic approach under these conditions. The results provide an overview of the different metabolic pathways affected during industrial biomass production by TRX2 gene manipulation. The oxidative stress-related genes, like those related with the glutathione metabolism, presented outstanding variations. The data also allowed us to propose new thioredoxin targets in S. cerevisiae, such as hexokinase 2, with relevance for industrial fermentation performance.


Assuntos
Dosagem de Genes , Regulação Fúngica da Expressão Gênica , Hexoquinase/metabolismo , Proteínas de Saccharomyces cerevisiae/biossíntese , Saccharomyces cerevisiae/enzimologia , Tiorredoxinas/biossíntese , Biomassa , Fermentação , Perfilação da Expressão Gênica , Saccharomyces cerevisiae/genética , Saccharomyces cerevisiae/crescimento & desenvolvimento , Vinho/microbiologia
19.
Methods Mol Biol ; 2378: 31-44, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-34985692

RESUMO

In the study of the unfolded protein response pathway, it is essential to determine the amount of unfolded proteins that the cell is accumulating. Besides being essential it is one of the most challenging technique because of the difficulty to detect unfolded proteins without producing protein denaturation with the method itself. Thus, indirect methods became very useful as the use of fluorescent proteins. In this chapter, we present some of the most used methods to indirectly measure protein folding in living cells using fluorescent proteins.


Assuntos
Estresse do Retículo Endoplasmático , Retículo Endoplasmático , Retículo Endoplasmático/metabolismo , Dobramento de Proteína , Proteínas/metabolismo , Resposta a Proteínas não Dobradas
20.
Microb Biotechnol ; 15(8): 2281-2291, 2022 08.
Artigo em Inglês | MEDLINE | ID: mdl-35536034

RESUMO

Phenylethanol (PE) and phenylethyl acetate (PEA) are commonly desired compounds in wine because of their rose-like aroma. The yeast S. cerevisiae produces the PE either through de novo biosynthesis by shikimate pathway followed by the Ehrlich pathway or the direct phenylalanine catabolism via Ehrlich pathway, and then converted into PEA. Previous work demonstrated that, compared to S. cerevisiae, other Saccharomyces species, such as S. kudriavzevii and S. uvarum, produce higher concentrations of PE and PEA from the precursor phenylalanine, which indicates differential activities of the biosynthetic-involved enzymes. A previous in-silico analysis suggested that the transcriptional activator Aro80p is one of the best candidates to explain these differences. An improved functional analysis identified significant radical amino acid changes in the S. uvarum and S. kudriavzevii Aro80p that could impact the expression of the catabolic genes ARO9 and ARO10, and hence, the production of PE from phenylalanine. Indeed, wine S. cerevisiae strains carrying the S. uvarum and S. kudriavzevii ARO80 alleles increased the production of both compounds in the presence of phenylalanine by increasing the expression of ARO9 and ARO10. This study provides novel insights of the unidentified Aro80p regulatory region and the potential usage of alternatives ARO80 alleles to enhance the PE and PEA concentration in wine.


Assuntos
Álcool Feniletílico , Vinho , Acetatos/metabolismo , Fermentação , Odorantes/análise , Fenilalanina/análise , Fenilalanina/metabolismo , Álcool Feniletílico/análise , Álcool Feniletílico/metabolismo , Saccharomyces cerevisiae/genética , Saccharomyces cerevisiae/metabolismo , Vinho/análise
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