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1.
J Ind Microbiol Biotechnol ; 49(6)2023 Feb 13.
Artigo em Inglês | MEDLINE | ID: mdl-36370452

RESUMO

Nitrogen is a critical nutrient in beverage fermentations, influencing fermentation performance and formation of compounds that affect organoleptic properties of the product. Traditionally, most commercial wine fermentations rely on Saccharomyces cerevisiae but the potential of alternative yeasts is increasingly recognised because of the possibility to deliver innovative products and process improvements. In this regard, Saccharomyces uvarum is an attractive non-traditional yeast that, while quite closely related to S. cerevisiae, displays a different fermentative and aromatic profile. Although S. uvarum is used in cider-making and in some winemaking, better knowledge of its physiology and metabolism is required if its full potential is to be realised. To address this gap, we performed a comparative analysis of the response of S. uvarum and S. cerevisiae to 13 different sources of nitrogen, assessing key parameters such as growth, fermentation performance, the production of central carbon metabolites and aroma volatile compounds. We observed that the two species differ in the production of acetate, succinate, medium-chain fatty acids, phenylethanol, phenylethyl acetate, and fusel/branched acids in ways that reflect different distribution of fluxes in the metabolic network. The integrated analysis revealed different patterns of yeast performance and activity linked to whether growth was on amino acids metabolised via the Ehrlich pathway or on amino acids and compounds assimilated through the central nitrogen core. This study highlights differences between the two yeasts and the importance that nitrogen metabolism can play in modulating the sensory profile of wine when using S. uvarum as the fermentative yeast.


Assuntos
Saccharomyces cerevisiae , Vinho , Saccharomyces cerevisiae/metabolismo , Fermentação , Vinho/análise , Nitrogênio/metabolismo , Aminoácidos/metabolismo , Metaboloma , Acetatos/metabolismo
2.
Mol Biol Evol ; 38(4): 1384-1401, 2021 04 13.
Artigo em Inglês | MEDLINE | ID: mdl-33252673

RESUMO

Hybrids between species often show extreme phenotypes, including some that take place at the molecular level. In this study, we investigated the phenotypes of an interspecies diploid hybrid in terms of protein-protein interactions inferred from protein correlation profiling. We used two yeast species, Saccharomyces cerevisiae and Saccharomyces uvarum, which are interfertile, but yet have proteins diverged enough to be differentiated using mass spectrometry. Most of the protein-protein interactions are similar between hybrid and parents, and are consistent with the assembly of chimeric complexes, which we validated using an orthogonal approach for the prefoldin complex. We also identified instances of altered protein-protein interactions in the hybrid, for instance, in complexes related to proteostasis and in mitochondrial protein complexes. Overall, this study uncovers the likely frequent occurrence of chimeric protein complexes with few exceptions, which may result from incompatibilities or imbalances between the parental proteomes.


Assuntos
Hibridização Genética , Mapas de Interação de Proteínas , Saccharomyces cerevisiae/metabolismo , Proteômica , Saccharomyces cerevisiae/genética
3.
Food Microbiol ; 104: 103981, 2022 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-35287810

RESUMO

Saccharomyces yeasts from different origins and species fermented in a semi-synthetic must containing aroma precursor of cv. Albariño and polyfunctional mercaptans precursors. The resulting wines were subjected to accelerate anoxic aging. Afterward, aroma profiles were analyzed by distinct gas chromatography methodologies. Cryotolerant strains showed better fermentation performances with significant differences in volatile and non-volatile fermentation products than Saccharomyces cerevisiae (S. cerevisiae). We suggested that the highest levels γ-butyrolactone and diethyl succinate in Saccharomyces uvarum (S. uvarum) strains, together with their substantial succinic acid yields, could be related to greater flux through the GABA shunt. These strains also had the highest production of ß-phenylethyl acetate, geraniol, and branched-chain ethyl esters. The latter compounds were highly increased by aging, while acetates and some terpenes decreased. S. kudriavzevii strains showed a remarkable ability to release polyfunctional mercaptans, with SK1 strain yielding up to 47-fold and 8-fold more 4-methyl-4-mercaptopentan-2-one (4MMP) than S. cerevisiae and S. uvarum strains, respectively. The wild S. cerevisiae beer isolate showed a particular aroma profile due to the highest production of ethyl 4-methylvalerate (lactic and fruity notes), γ-octalactone (coconut), and furfurylthiol (roasted coffee). The latter compound is possibly produced from the pentose phosphate pathway (PPP). Since erythritol, another PPP intermediate was largely produced by this strain.


Assuntos
Saccharomyces , Vinho , Odorantes/análise , Saccharomyces/metabolismo , Saccharomyces cerevisiae/metabolismo , Vinho/análise
4.
FEMS Yeast Res ; 19(5)2019 08 01.
Artigo em Inglês | MEDLINE | ID: mdl-31344230

RESUMO

The microbial consortium of wine fermentations is highly dependent upon winemaking decisions made at crush, including the decision to inoculate and the decision to add sulfur dioxide (SO2) to the must. To investigate this, Chardonnay grape juice was subjected to two inoculation treatments (uninoculated and pied de cuve inoculation) as well as two SO2 addition concentrations (0 and 40 mg/L). The bacterial communities, fungal communities and Saccharomyces populations were monitored throughout fermentation using culture-dependent and culture-independent techniques. After fermentation, the wines were evaluated by a panel of experts. When no SO2 was added, the wines underwent alcoholic fermentation and malolactic fermentation simultaneously. Tatumella bacteria were present in significant numbers, but only in the fermentations to which no SO2 was added, and were likely responsible for the malolactic fermentation observed in these treatments. All fermentations were dominated by a genetically diverse indigenous population of Saccharomyces uvarum, the highest diversity of S. uvarum strains to be identified to date; 150 unique strains were identified, with differences in strain composition as a result of SO2 addition. This is the first report of indigenous S. uvarum strains dominating and completing fermentations at a commercial winery in North America.


Assuntos
Fermentação/efeitos dos fármacos , Consórcios Microbianos/efeitos dos fármacos , Saccharomyces/efeitos dos fármacos , Dióxido de Enxofre/farmacologia , Vinho/análise , Vinho/microbiologia , Bactérias/efeitos dos fármacos , Variação Genética , Sequenciamento de Nucleotídeos em Larga Escala , Microbiologia Industrial , Malato Desidrogenase/metabolismo , América do Norte , Saccharomyces/genética , Sensação , Vitis/microbiologia
5.
Mol Biol Evol ; 34(7): 1596-1612, 2017 07 01.
Artigo em Inglês | MEDLINE | ID: mdl-28369610

RESUMO

Hybridization is often considered maladaptive, but sometimes hybrids can invade new ecological niches and adapt to novel or stressful environments better than their parents. The genomic changes that occur following hybridization that facilitate genome resolution and/or adaptation are not well understood. Here, we examine hybrid genome evolution using experimental evolution of de novo interspecific hybrid yeast Saccharomyces cerevisiae × Saccharomyces uvarum and their parentals. We evolved these strains in nutrient-limited conditions for hundreds of generations and sequenced the resulting cultures identifying numerous point mutations, copy number changes, and loss of heterozygosity (LOH) events, including species-biased amplification of nutrient transporters. We focused on a particularly interesting example, in which we saw repeated LOH at the high-affinity phosphate transporter gene PHO84 in both intra- and interspecific hybrids. Using allele replacement methods, we tested the fitness of different alleles in hybrid and S. cerevisiae strain backgrounds and found that the LOH is indeed the result of selection on one allele over the other in both S. cerevisiae and the hybrids. This is an example where hybrid genome resolution is driven by positive selection on existing heterozygosity and demonstrates that even infrequent outcrossing may have lasting impacts on adaptation.


Assuntos
Adaptação Fisiológica/genética , Perda de Heterozigosidade/genética , Evolução Biológica , Genoma/genética , Hibridização Genética/genética , Saccharomyces/genética , Saccharomyces cerevisiae/genética
6.
Yeast ; 35(1): 157-171, 2018 01.
Artigo em Inglês | MEDLINE | ID: mdl-29131448

RESUMO

Interspecific hybrids among species in the Saccharomyces genus are frequently detected in anthropic habitats and can also be obtained easily in the laboratory. This occurs because the most important genetic barriers among Saccharomyces species are post-zygotic. Depending on several factors, including the involved strains, the hybridization mechanism and stabilization conditions, hybrids that bear differential genomic constitutions, and hence phenotypic variability, can be obtained. In the present study, Saccharomyces cerevisiae × Saccharomyces uvarum hybrids were constructed using genetically and physiologically different S. uvarum parents at distinct temperatures (13 and 20°C). The effect of those variables on the main oenological features of the wines obtained with these hybrids was evaluated. Hybrids were successfully obtained in all cases. However, genetic stabilization based on successive fermentations in white wine at 13°C was significantly longer than that at 20°C. Our results demonstrated that, irrespective of the S. uvarum parent and temperature used for hybrid generation and stabilization, similar physicochemical and aromatic features were found in wines. The hybrids generated herein were characterized by low ethanol production, high glycerol synthesis and the capacity to grow at low temperature and to produce malic acid with particular aroma profiles. These features make these hybrids useful for the new winemaking industry within the climate change era frame. Copyright © 2017 John Wiley & Sons, Ltd.


Assuntos
Hibridização Genética , Saccharomyces/genética , Vinho/microbiologia , Acetaldeído/química , Acetaldeído/metabolismo , Álcoois/química , Álcoois/metabolismo , DNA Fúngico/genética , Ésteres/química , Ésteres/metabolismo , Fermentação , Indústria Alimentícia , Seleção Genética , Terpenos/química , Terpenos/metabolismo
7.
Yeast ; 35(1): 141-156, 2018 01.
Artigo em Inglês | MEDLINE | ID: mdl-28779574

RESUMO

In the last two decades, the extensive genome sequencing of strains belonging to the Saccharomyces genus has revealed the complex reticulated evolution of this group. Among the various evolutionary mechanisms described, the introgression of large chromosomal regions resulting from interspecific hybridization has recently shed light on Saccharomyces uvarum species. In this work we provide the de novo assembled genomes of four S. uvarum strains presenting more than 712 kb of introgressed loci inherited from both Saccharomyces eubayanus and Saccharomyces kudriavzevii species. In order to study the prevalence of such introgressions in a large population, we designed multiplexed PCR markers able to survey the inheritance of eight chromosomal regions. Our data confirm that introgressions are widely disseminated in Holarctic S. uvarum populations and are more frequently found in strains isolated from human-related fermentations. According to the origin of the strains (nature or cider- or wine-related processes), some loci are over-represented, suggesting their positive selection by human activity. Except for one locus located on chromosome 7, the introgressions present a low level of heterozygozity similar to that observed for nine neutral markers (microsatellites). Finally, most of the loci tested showed an expected Mendelian segregation after meiosis and can recombine with their chromosomal counterpart in S. uvarum. Copyright © 2017 John Wiley & Sons, Ltd.


Assuntos
Bebidas Alcoólicas/microbiologia , Cromossomos Fúngicos/genética , Hibridização Genética , Saccharomyces/genética , Mapeamento Cromossômico , DNA Fúngico/genética , Fermentação , Marcadores Genéticos , Variação Genética , Genoma Fúngico , Genótipo , Humanos , Repetições de Microssatélites , Reação em Cadeia da Polimerase/métodos , Especificidade da Espécie
8.
Lett Appl Microbiol ; 67(1): 72-78, 2018 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-29604215

RESUMO

The aim of the present work was to screen a pool of 75 yeasts belonging to the species Saccharomyces cerevisiae and Saccharomyces uvarum in order to select the strains endowed with ß-glucosidase activity. The first screening was a qualitative assay based on chromogenic substrates (arbutin and esculin). The second screening was the quantitative evaluation of the ß-glucosidase activity via a p-nitrophenyl-ß-d-glucopyranoside assay. The measurement was performed on three different cell preparations, including the extracellular compartment, the cell lysates and the whole cells. This study pointed out the high frequency of ß-glucosidase activity in S. uvarum strains. In particular, we retrieved three promising S. uvarum strains, CRY14, VA42 and GRAS14, featuring a high enzymatic activity, exploitable for winemaking. SIGNIFICANCE AND IMPACT OF THE STUDY: In yeasts, ß-glucosidase activity has been extensively described, especially in non-Saccharomyces species, while there is only little evidence of this activity in strains belonging to the Saccharomyces species. In winemaking, ß-glucosidase plays essential roles in the hydrolysis of glyco-conjugated precursors and the release of active aromatic compounds. This study provides new insights into the ß-glucosidase activity in strains belonging to Saccharomyces cerevisiae and Saccharomyces uvarum species, which are the most important strains in wine industry. Our results point out a marked enzymatic activity for the tested S. uvarum strains. These strains could be exploited for their potential ability to enhance the aroma profiles of wine. In addition, they could be potential sources for the commercial production of enzymes to be applied in winemaking.


Assuntos
Saccharomyces cerevisiae/enzimologia , Saccharomyces cerevisiae/metabolismo , Vinho/microbiologia , beta-Glucosidase/metabolismo , Arbutina/metabolismo , Esculina/metabolismo , Fermentação , Glucosídeos/metabolismo , Odorantes , Saccharomyces cerevisiae/classificação , Saccharomyces cerevisiae/isolamento & purificação , Vinho/análise
9.
FEMS Yeast Res ; 17(3)2017 05 01.
Artigo em Inglês | MEDLINE | ID: mdl-28449102

RESUMO

Saccharomyces uvarum is a good wine yeast species that may have great potential for the future. However, sulfur tolerance of most S. uvarum strains is very poor. In addition there is still little information about the SSU1 gene of S. uvarum, which encodes a putative transporter conferring sulfite tolerance. In order to analyze the function of the SSU1 gene, two expression vectors that contained different SSU1 genes were constructed and transferred into a sulfite-tolerant S. uvarum strain, A9. Then sulfite tolerance, SO2 production, and PCR, sequencing, RT-qPCR and transcriptome analyses were used to access the function of the S. uvarum SSU1 gene. Our results illustrated that enhancing expression of the SSU1 gene can promote sulfite resistance in S. uvarum, and an insertion fragment ahead of the additional SSU1 gene, as seen in some alleles, could affect the expression of other genes and the sulfite tolerance level of S. uvarum. This is the first report on enhancing the expression of the SSU1 gene of S. uvarum.


Assuntos
Proteínas de Transporte de Ânions/genética , Regulação Fúngica da Expressão Gênica , Saccharomyces/efeitos dos fármacos , Sulfitos/farmacologia , Transcriptoma , Alelos , Proteínas de Transporte de Ânions/agonistas , Proteínas de Transporte de Ânions/metabolismo , Tolerância a Medicamentos/genética , Fermentação , Vetores Genéticos/química , Vetores Genéticos/metabolismo , Anotação de Sequência Molecular , Saccharomyces/genética , Saccharomyces/metabolismo , Dióxido de Enxofre/metabolismo , Transformação Genética , Vinho/análise
10.
J Appl Microbiol ; 123(2): 450-463, 2017 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-28543932

RESUMO

AIMS: Evaluating the winemaking stress tolerance of a set of both Saccharomyces eubayanus and Saccharomyces uvarum strains from diverse Patagonian habitats. METHODS AND RESULTS: Yeast strains growth was analysed under increasing ethanol concentrations; all of them were able to grow until 8% v/v ethanol. The effect of different temperature and pH conditions as well as at SO2 and hexose concentrations was evaluated by means of a central composite experimental design. Only two S. uvarum strains (NPCC 1289 and 1321) were able to grow in most stress conditions. Kinetic parameters analysed (µmax and λ) were statistically affected by temperature, pH and SO2 , but not influenced by sugar concentration. The obtained growth model was used for predicting optimal growth conditions for both strains: 20°C, 0% w/v SO2 and pH 4·5. CONCLUSIONS: Strains from human-associated environments (chichas) presented the highest diversity in the response to different stress factors. Two S. uvarum strains from chichas demonstrated to be the most tolerant to winemaking conditions. SIGNIFICANCE AND IMPACT OF THE STUDY: This work evidenced the potential use of two S. uvarum yeast strains as starter cultures in wines fermented at low temperatures. Saccharomyces eubayanus was significantly affected by winemaking stress conditions, limiting its use in this industry.


Assuntos
Etanol/metabolismo , Saccharomyces/metabolismo , Vinho/microbiologia , Reatores Biológicos , Fermentação , Saccharomyces cerevisiae/metabolismo , Temperatura , Vinho/análise
11.
Appl Microbiol Biotechnol ; 101(6): 2507-2521, 2017 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-27933455

RESUMO

The selection and genetic improvement of wine yeast is an ongoing process, since yeast strains should match new technologies in winemaking to satisfy evolving consumer preferences. A large genetic background is the necessary starting point for any genetic improvement programme. For this reason, we collected and characterized a large number of strains belonging to Saccharomyces uvarum. In particular, 70 strains were isolated from cold-stored must samples: they were identified and compared to S. uvarum strains originating from different collections, regarding fermentation profile, spore viability and stress response. The results demonstrate a large biodiversity among the new isolates, with particular emphasis to fermentation performances, genotypes and high spore viability, making the isolates suitable for further genetic improvement programmes. Furthermore, few of them are competitive with Saccharomyces cerevisiae and per se, suitable for wine fermentation, due to their resistance to stress, short lag phase and fermentation by-products.


Assuntos
Variação Genética , Filogenia , Saccharomyces cerevisiae/genética , Saccharomyces/genética , Esporos Fúngicos/genética , Vitis/microbiologia , Fermentação , Genótipo , Técnicas de Tipagem Micológica , Fenótipo , Saccharomyces/crescimento & desenvolvimento , Saccharomyces/metabolismo , Saccharomyces cerevisiae/crescimento & desenvolvimento , Saccharomyces cerevisiae/metabolismo , Especificidade da Espécie , Esporos Fúngicos/crescimento & desenvolvimento , Esporos Fúngicos/metabolismo , Vitis/metabolismo , Vinho/análise
12.
J Ind Microbiol Biotechnol ; 44(11): 1541-1550, 2017 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-28856461

RESUMO

As a byproduct of yeast valine metabolism during fermentation, diacetyl can produce a buttery aroma in wine. However, high diacetyl concentrations generate an aromatic off-flavor and poor quality in wine. 2,3-Butanediol dehydrogenase encoded by BDH1 can catalyze the two reactions of acetoin from diacetyl and 2,3-butanediol from acetoin. BDH2 is a gene adjacent to BDH1, and these genes are regulated reciprocally. In this study, BDH1 and BDH2 were overexpressed in Saccharomyces uvarum to reduce the diacetyl production of wine either individually or in combination. Compared with those in the host strain WY1, the diacetyl concentrations in the recombinant strains WY1-1 with overexpressed BDH1, WY1-2 with overexpressed BDH2 alone, and WY1-12 with co-overexpressed BDH1 and BDH2 were decreased by 39.87, 33.42, and 46.71%, respectively. BDH2 was only responsible for converting diacetyl into acetoin, but not for the metabolic pathway of acetoin to 2,3-butanediol in S. uvarum. This study provided valuable insights into diacetyl reduction in wine.


Assuntos
Diacetil/análise , Proteínas Fúngicas/genética , Regulação Fúngica da Expressão Gênica , Saccharomyces/genética , Saccharomyces/metabolismo , Vinho/análise , Acetoína/metabolismo , Butileno Glicóis/metabolismo , Meios de Cultura/química , Fermentação , Manipulação de Alimentos , Microbiologia de Alimentos , Proteínas Fúngicas/metabolismo , Redes e Vias Metabólicas , Plasmídeos/genética , Plasmídeos/metabolismo , Proteínas Recombinantes/genética , Proteínas Recombinantes/metabolismo , Compostos Orgânicos Voláteis/análise
13.
FEMS Yeast Res ; 16(2): fow002, 2016 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-26772797

RESUMO

Considered as a sister species of Saccharomyces cerevisiae, S. uvarum is, to a lesser extent, an interesting species for fundamental and applied research studies. Despite its potential interest as a new gene pool for fermenting agents, the intraspecific molecular genetic diversity of this species is still poorly investigated. In this study, we report the use of nine microsatellite markers to describe S. uvarum genetic diversity and population structure among 108 isolates from various geographical and substrate origins (wine, cider and natural sources). Our combined microsatellite markers set allowed differentiating 89 genotypes. In contrast to S. cerevisiae genetic diversity, wild and human origin isolates were intertwined. A total of 75% of strains were proven to be homozygotes and estimated heterozygosity suggests a selfing rate above 0.95 for the different population tested here. From this point of view, the S. uvarum life cycle appears to be more closely related to S. paradoxus or S. cerevisiae of natural resources than S. cerevisiae wine isolates. Population structure could not be correlated to distinct geographic or technological origins, suggesting lower differentiation that may result from a large exchange between human and natural populations mediated by insects or human activities.


Assuntos
Variação Genética , Repetições de Microssatélites , Saccharomyces/classificação , Saccharomyces/genética , Microbiologia de Alimentos , Plantas/microbiologia
14.
FEMS Yeast Res ; 16(6)2016 09.
Artigo em Inglês | MEDLINE | ID: mdl-27589939

RESUMO

In the past, the galactose-negative (Gal(-)) phenotype was a key physiological character used to distinguish Saccharomyces bayanus from S. cerevisiae In this work, we investigated the inactivation of GAL gene networks in S. bayanus, which is an S. uvarum/S. eubayanus hybrid, and in S. cerevisiae wine strains erroneously labelled 'S. bayanus'. We made an inventory of their GAL genes using genomes that were either available publicly, re-sequenced by us, or assembled from public data and completed with targeted sequencing. In the S. eubayanus/S. uvarum CBS 380(T) hybrid, the GAL/MEL network is composed of genes from both parents: from S. uvarum, an otherwise complete set that lacks GAL4, and from S. eubayanus, a truncated version of GAL4 and an additional copy of GAL3 and GAL80 Similarly, two different truncated GAL4 alleles were found in S. cerevisiae wine strains EC1118 and LalvinQA23. The lack of GAL4 activity in these strains was corrected by introducing a full-length copy of S. cerevisiae GAL4 on a CEN4/ARS plasmid. Transformation with this plasmid restored galactose utilisation in Gal(-) strains, and melibiose fermentation in strain CBS 380(T) The melibiose fermentation phenotype, formerly regarded as characteristic of S. uvarum, turned out to be widespread among Saccharomyces species.


Assuntos
Proteínas de Ligação a DNA/genética , Proteínas de Ligação a DNA/metabolismo , Galactose/metabolismo , Redes e Vias Metabólicas , Proteínas de Saccharomyces cerevisiae/genética , Proteínas de Saccharomyces cerevisiae/metabolismo , Saccharomyces/genética , Saccharomyces/metabolismo , Deleção de Sequência , Fatores de Transcrição/genética , Fatores de Transcrição/metabolismo , Teste de Complementação Genética , Genótipo , Regulon , Saccharomyces/classificação , Vinho/microbiologia
15.
J Appl Microbiol ; 119(1): 149-61, 2015 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-25892524

RESUMO

AIMS: The present work proposes a two-step molecular strategy to select inter- and intra-species Saccharomyces hybrids obtained by spore-to-spore mating, one of the most used methods for generating improved hybrids from homothallic wine yeasts. METHODS AND RESULTS: As low spore viability and haplo-selfing are the main causes of failed mating, at first, we used colony screening PCR (csPCR) of discriminative gene markers to select hybrids directly on dissection plate and discard homozygous diploid colonies arisen from one auto-diploidized progenitor. Then, pre-selected candidates were submitted to recursive streaking and conventional PCR in order to discriminate between the hybrids with stable genomic background and the false-positive admixtures of progenitor cells both undergone haplo-selfing. csPCRs of internal transcribed spacer (ITS) 1 or 2, and the subsequent digestion with diagnostic endonucleases HaeIII and RsaI, respectively, were efficient to select six new Saccharomyces cerevisiae × Saccharomyces uvarum hybrids from 64 crosses. Intragenic minisatellite regions in PIR3, HSP150, and DAN4 genes showed high inter-strain size variation detectable by cost-effective agarose gel electrophoresis and were successful to validate six new intra-species S. cerevisiae hybrids from 34 crosses. CONCLUSIONS: Both protocols reduce significantly the number of massive DNA extractions, prevent misinterpretations caused by one or both progenitors undergone haplo-selfing, and can be easily implemented in yeast labs without any specific instrumentation. SIGNIFICANCE AND IMPACT OF THE STUDY: The study provides a method for the marker-assisted selection of several inter- and intra-species yeast hybrids in a cost-effective, rapid and reproducible manner.


Assuntos
Hibridização Genética , Saccharomyces cerevisiae/genética , Fermentação , Marcadores Genéticos , Reação em Cadeia da Polimerase , Saccharomyces cerevisiae/metabolismo , Vinho/análise , Vinho/microbiologia
16.
Food Microbiol ; 46: 92-99, 2015 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-25475271

RESUMO

We present a genetic characterization of 65 isolates of Saccharomyces uvarum isolated from wineries in New Zealand, along with the complete nucleotide sequence of a single sulfite-tolerant isolate. The genome of the New Zealand isolate averaged 99.85% nucleotide identity to CBS7001, the previously sequenced strain of S. uvarum. However, three genomic segments (37-87 kb) showed 10% nucleotide divergence from CBS7001 but 99% identity to Saccharomyces eubayanus. We conclude that these three segments appear to have been introgressed from that species. The nucleotide sequence of the internal transcribed spacer (ITS) region from other New Zealand isolates were also very similar to that of CBS7001, and hybrids showed complete genetic compatibility for some strains, with tetrads giving four viable progeny that showed 2:2 segregations of marker genes. Some strains showed high tolerance to sulfite, with genetic analysis indicating linkage of this trait to the transcription factor FZF1, but not to SSU1, the sulfite efflux pump that it regulates in order to confer sulfite tolerance in Saccharomyces cerevisiae. The fermentation characteristics of selected strains of S. uvarum showed exceptionally good cold fermentation characteristics, superior to the best commercially available strains of S. cerevisiae.


Assuntos
Saccharomyces/genética , Saccharomyces/isolamento & purificação , Vinho/microbiologia , Sequência de Bases , Fermentação , Repetições de Microssatélites , Dados de Sequência Molecular , Técnicas de Tipagem Micológica , Nova Zelândia , Filogenia , Saccharomyces/classificação
17.
Foods ; 13(11)2024 May 24.
Artigo em Inglês | MEDLINE | ID: mdl-38890877

RESUMO

This study investigates innovative approaches to improve the quality and aroma characteristics of Muscat Hamburg wine production by substituting the conventional Saccharomyces cerevisiae yeast with an efficient fermentation strain of Schizosaccharomyces pombe. The typical use of S. cerevisiae in Muscat Hamburg wine often leads to uniformity and prolonged processing times, requiring subsequent malolactic fermentation to degrade excessive malic acid. The study advocates for the replacement of S. cerevisiae with a specific S. pombe strain, Sp-410, isolated from the fermented grains of sauce-flavor Baijiu, a Chinese spirit. Muscat Hamburg wine fermented with the S. pombe strain demonstrates decreased malic acid levels, offering a potential alternative to malolactic fermentation. However, exclusive S. pombe fermentation may result in an overproduction of acetic acid metabolites, leading to a monotonous taste. In response, the study proposes a mixed fermentation approach, combining the S. pombe strain with a Saccharomyces uvarum strain and a non-Saccharomyces yeast, Torulaspora delbrueckii. The optimized mixed fermentation strategies (M:SP+TD and M60SP+TD) involve specific proportions and intervals of inoculation, aiming to enhance the quality and aroma complexity of Muscat Hamburg wine. In conclusion, this research contributes to advancing the production of high-quality Muscat Hamburg wines, utilizing S. pombe as the primary yeast strain and implementing mixed fermentation methodologies.

18.
Microorganisms ; 11(9)2023 Aug 23.
Artigo em Inglês | MEDLINE | ID: mdl-37763982

RESUMO

The increasing demand for craft beer is driving the search for novel ale yeast cultures from brewing-related wild environments. The focus of bioprospecting for craft cultures is to identify feral yeasts suitable to imprint unique sensorial attributes onto the final product. Here, we integrated phylogenetic, genotypic, genetic, and metabolomic techniques to demonstrate that sour beer during aging in wooden barrels is a source of suitable craft ale yeast candidates. In contrast to the traditional lambic beer maturation phase, during the aging of sour-matured production-style beer, different biotypes of Saccharomyces cerevisiae dominated the cultivable in-house mycobiota, which were followed by Pichia membranifaciens, Brettanomyces bruxellensis, and Brettanomyces anomalus. In addition, three putative S. cerevisiae × Saccharomyces uvarum hybrids were identified. S. cerevisiae feral strains sporulated, produced viable monosporic progenies, and had the STA1 gene downstream as a full-length promoter. During hopped wort fermentation, four S. cerevisiae strains and the S. cerevisiae × S. uvarum hybrid WY213 exceeded non-Saccharomyces strains in fermentative rate and ethanol production except for P. membranifaciens WY122. This strain consumed maltose after a long lag phase, in contrast to the phenotypic profile described for the species. According to the STA1+ genotype, S. cerevisiae partially consumed dextrin. Among the volatile organic compounds (VOCs) produced by S. cerevisiae and the S. cerevisiae × S. uvarum hybrid, phenylethyl alcohol, which has a fruit-like aroma, was the most prevalent. In conclusion, the strains characterized here have relevant brewing properties and are exploitable as indigenous craft beer starters.

19.
Cells ; 11(4)2022 02 11.
Artigo em Inglês | MEDLINE | ID: mdl-35203287

RESUMO

Saccharomyces uvarum is one of the few fermentative species that can be used in winemaking, but its weak sulfite tolerance is the main reason for its further use. Previous studies have shown that the expression of the methionine synthase gene (MET4) is upregulated in FZF1 (a gene encoding a putative zinc finger protein, which is a positive regulator of the transcription of the cytosolic sulfotransferase gene SSU1) overexpression transformant strains, but its exact function is unknown. To gain insight into the function of the MET4 gene, in this study, a MET4 overexpression vector was constructed and transformed into S. uvarum strain A9. The MET4 transformants showed a 20 mM increase in sulfite tolerance compared to the starting strain. Ninety-two differential genes were found in the transcriptome of A9-MET4 compared to the A9 strain, of which 90 were upregulated, and two were downregulated. The results of RT-qPCR analyses confirmed that the expression of the HOMoserine requiring gene (HOM3) in the sulfate assimilation pathway and some fermentation-stress-related genes were upregulated in the transformants. The overexpression of the MET4 gene resulted in a significant increase in sulfite tolerance, the upregulation of fermentation-stress-related gene expression, and significant changes in the transcriptome profile of the S. uvarum strain.


Assuntos
Fatores de Transcrição de Zíper de Leucina Básica , Proteínas Fúngicas , Saccharomyces , Sulfitos , Fatores de Transcrição de Zíper de Leucina Básica/genética , Fatores de Transcrição de Zíper de Leucina Básica/metabolismo , Proteínas Fúngicas/genética , Proteínas Fúngicas/metabolismo , Saccharomyces/genética , Saccharomyces/metabolismo , Sulfitos/metabolismo , Regulação para Cima
20.
Int J Food Microbiol ; 365: 109554, 2022 Mar 16.
Artigo em Inglês | MEDLINE | ID: mdl-35093767

RESUMO

Interest in the use of non-conventional yeasts in wine fermentation has been increased in the last years in the wine sector. The main objective of this manuscript was to explore the aromatic diversity produced by wild and non-wine strains of S. cerevisiae, S. eubayanus, S. kudriavzevii, and S. uvarum species in young and bottle-aged Tempranillo wines as well as evaluate their fermentation capacity and the yield on ethanol, glycerol, and organic acids, that can contribute to diminishing the effects of climate change on wines. S. uvarum strain U1 showed the highest ability to release or de novo produce monoterpenes, such as geraniol and citronellol, whose values were 1.5 and 3.5-fold higher than those of the wine S. cerevisiae strain. We found that compared to the normal values for red wines, ß-phenylethyl acetate was highly synthesized by U1 and E1 strains, achieving 1 mg/L. Additionally, after aging, wines of S. eubayanus strains contained the highest levels of this acetate. Malic acid was highly degraded by S. kudriavzevii yeasts, resulting in the highest yields of lactic acid (>5-fold) and ethyl lactate (>2.8-fold) in their wines. In aged wines, we observed that the modulating effects of yeast strain were very high in ß-ionone. S. uvarum strains U1 and BMV58 produced an important aging attribute, ethyl isobutyrate, which was highly enhanced during the aging. Also, the agave S. cerevisiae strain develops an essential aroma after aging, reaching the highest ethyl leucate contents. According to the results obtained, the use of wild non-wine strains of S. cerevisiae and strains of the cryotolerant species S. eubayanus, S. kudriavzevii, and S. uvarum in Tempranillo wine fermentation increase the aroma complexity. In addition, wines from S. kudriavzevii strains had twice additional glycerol, those from S. uvarum 4-fold more succinic acid, while wines from wild strains yielded 1% v/v less ethanol which may solve wine problems associated with climate change.


Assuntos
Saccharomyces , Vitis , Vinho , Fermentação , Odorantes/análise , Saccharomyces cerevisiae , Vinho/análise
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