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1.
Food Chem ; 340: 127910, 2021 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-32882475

RESUMO

The aim of this study is to monitor the evolution of the principal phenolic compounds throughout the fermentation stage of white wines treated with different enzymes. The effect of five commercial enzymes on the evolution of the phenolic profile during the alcoholic fermentation of white wines obtained from Feteasca regala and Sauvignon blanc varieties was evaluated. Physicochemical properties of resulted wine samples have been analyzed according to OIV standards and regulations. The evolution of the principal phenolic compounds was carried out using HPLC method. Enzymatic treatments did not significantly affect the physicochemical composition of the obtained wines. The analyzed samples showed different variations on the phenolic compound content, depending on the type of added enzyme and grape variety. The statistical analysis confirms that enzymes significantly contributed to the enrichment of the wines with phenolic compounds, especially with p-coumaric, gentisic, caftaric, and protocatechuic acids.


Assuntos
Enzimas/metabolismo , Fenóis/análise , Vitis/química , Vinho/análise , Cromatografia Líquida de Alta Pressão , Enzimas/química , Fermentação , Hidroxibenzoatos/análise , Fenóis/química , Fenóis/metabolismo , Vitis/microbiologia , Vinho/microbiologia
2.
Int J Food Microbiol ; 337: 108954, 2021 Jan 16.
Artigo em Inglês | MEDLINE | ID: mdl-33202298

RESUMO

Non-Saccharomyces yeasts have increasingly been used in vinification recently. This is particularly true of Torulaspora delbrueckii and Metschnikowia pulcherrima, which are inoculated before S. cerevisiae, to complete a sequential alcoholic fermentation. This paper aims to study the effects of these two non-Saccharomyces yeasts on malolactic fermentation (MLF) carried out by two strains of Oenococcus oeni, under cellar conditions. Oenological parameters, and volatile and phenolic compounds were analysed in wines. The wines were tasted, and the microorganisms identified. In general, non-Saccharomyces created more MLF friendly conditions, largely because of lower concentrations of SO2 and medium chain fatty acids. The most favourable results were observed in wines inoculated with T. delbrueckii, that seemed to promote the development of O. oeni and improve MLF performance.


Assuntos
Metschnikowia/metabolismo , Oenococcus/metabolismo , Torulaspora/metabolismo , Vinho/análise , Vinho/microbiologia , Fermentação , Ácido Láctico/metabolismo , Malatos/metabolismo , Oenococcus/crescimento & desenvolvimento , Fenóis/análise , Fenóis/metabolismo , Compostos Orgânicos Voláteis/análise , Compostos Orgânicos Voláteis/metabolismo
3.
Food Chem ; 334: 127593, 2021 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-32711276

RESUMO

ß-Glucosidases play an important role in food industry. Oenococcus oeni are typical lactic acid bacteria that initiate malolactic fermentation of wines. 35 ß-glucosidases from O. oeni were selected and their conserved domains and evolutionary relationships were further explored in this study. The homology analysis results indicated that 35 ß-glucosidases were basically derived from GH1 and GH3 family. A novel ß-glucosidase was successfully expressed and characterized. The recombinant protein, referred to as BGL0224, consisted of a total 480 amino acids with an apparent molecular weight of 55.15 kDa and was classified as GH1 family. It achieved the highest activity at pH 5.0 and 50 °C. The activity and stability were significantly increased when 12% ethanol was supplemented to the enzyme. Using p-NPG as substrate, the Km, Vmax and Kcat of BGL0224 were 0.34 mM, 382.81 U/mg and 351.88 s-1, respectively. In all, BGL0224 has good application prospects in food industry.


Assuntos
Oenococcus/enzimologia , Vinho/microbiologia , beta-Glucosidase/química , beta-Glucosidase/metabolismo , Estabilidade Enzimática , Etanol/química , Fermentação , Microbiologia de Alimentos , Peso Molecular , Filogenia , Proteínas Recombinantes/química , Proteínas Recombinantes/genética , Proteínas Recombinantes/metabolismo , Homologia de Sequência de Aminoácidos , beta-Glucosidase/genética
4.
Int J Food Microbiol ; 335: 108883, 2020 Dec 16.
Artigo em Inglês | MEDLINE | ID: mdl-32956955

RESUMO

Kpkt is a yeast killer toxin, naturally produced by Tetrapisispora phaffii, with possible applications in winemaking due to its antimicrobial activity on wine-related yeasts including Kloeckera/Hanseniaspora, Saccharomycodes and Zygosaccharomyces. Here, Kpkt coding gene was expressed in Komagataella phaffii (formerly Pichia pastoris) and the bioreactor production of the recombinant toxin (rKpkt) was obtained. Moreover, to produce a ready-to-use preparation of rKpkt, the cell-free supernatant of the K. phaffii recombinant killer clone was 80-fold concentrated and lyophilized. The resulting preparation could be easily solubilized in sterile distilled water and maintained its killer activity for up to six months at 4 °C. When applied to grape must, it exerted an extensive killer activity on wild wine-related yeasts while proving compatible with the fermentative activity of actively growing Saccharomyces cerevisiae starter strains. Moreover, it displayed a strong microbicidal effect on a variety of bacterial species including lactic acid bacteria and food-borne pathogens. On the contrary it showed no lethal effect on filamentous fungi and on Ceratitis capitata and Musca domestica, two insect species that may serve as non-mammalian model for biomedical research. Based on these results, bioreactor production and lyophilization represent an interesting option for the exploitation of this killer toxin that, due to its spectrum of action, may find application in the control of microbial contaminations in the wine and food industries.


Assuntos
Fatores Matadores de Levedura/farmacologia , Vinho/microbiologia , Anti-Infecciosos/metabolismo , Anti-Infecciosos/farmacologia , Reatores Biológicos/microbiologia , Fermentação , Indústria Alimentícia , Microbiologia de Alimentos , Liofilização , Fatores Matadores de Levedura/biossíntese , Viabilidade Microbiana , Proteínas Recombinantes/biossíntese , Proteínas Recombinantes/farmacologia , Leveduras/efeitos dos fármacos
5.
Sheng Wu Gong Cheng Xue Bao ; 36(8): 1640-1649, 2020 Aug 25.
Artigo em Chinês | MEDLINE | ID: mdl-32924362

RESUMO

Ethyl carbamate (EC) is a carcinogen detected in fermented foods and alcohol beverages. Excessive intake of EC is possibly harmful to health. Enzymatic degradation is one of the most effective approaches for reducing EC in fermented foods. Urease catalyzes the hydrolysis of both EC and urea. This confers urease a good application prospect in reducing EC and its precursor urea in fermented foods. Currently, degradation of EC in alcohol beverages by urease is inefficient due to its low urethanase activity and poor affinity to EC. Urease from Bacillus amyloliquefaciens JP-21 was successfully expressed in Escherichia coli at the level of 3 292 U/L urease and 227.3 U/L urethanase. Two key residues M326 and M374 were characterized that might block the binding of enzyme to EC, through simulating docking the structure of catalytic subunit UreC of urease with EC. Three mutants (M374A, M374T and M326V) of urease with improved urethanase activity were obtained by performing point saturated mutagenesis approach. Using EC as the substrate, Km values of M374A, M374T and M326V were detected to be 101.8 mmol/L, 129.5 mmol/L and 121.7 mmol/L, respectively, which were decreased by 37.47%-50.82% compared with that of the wild type urease. These mutants can degrade more than 97% of urea in rice wine and mutant M374T shows the highest degradation of EC in rice wine. EC content in rice wine was reduced from 525 µg/L to 393 µg/L by using M374T, and the EC degradation rate of it is 0.97 folds higher than that of the wild type urease. The results are of great significance for engineering the catalytic properties of urease and improving its industrial properties, and lays a good foundation for developing strategies to reducing microbial metabolic ammonia (amine) hazards in fermented foods.


Assuntos
Bacillus amyloliquefaciens , Microbiologia de Alimentos , Oryza , Urease , Uretana , Bacillus amyloliquefaciens/enzimologia , Bacillus amyloliquefaciens/genética , Carcinógenos/metabolismo , Mutagênese Sítio-Dirigida , Urease/genética , Urease/metabolismo , Uretana/metabolismo , Vinho/microbiologia
6.
Int J Food Microbiol ; 333: 108797, 2020 Nov 16.
Artigo em Inglês | MEDLINE | ID: mdl-32738750

RESUMO

Acetic acid bacteria form a complex microbiota that plays a fundamental role in the industrial production of vinegar through the incomplete oxidation reaction from ethanol to acetic acid. The organoleptic properties and the quality of vinegar are influenced by many factors, especially by the raw material used as acetification substrate, the microbial diversity and the technical methods employed in its production. The metaproteomics has been considered, among the new methods employed for the investigation of microbial communities, since it may provide information about the microbial biodiversity and behaviour by means of a protein content analysis. In this work, alcohol wine vinegar was produced through a submerged culture of acetic acid bacteria using a pilot acetator, operated in a semi-continuous mode, where the main system variables were monitored and the cycle profile throughout the acetification was obtained. Through a first approach, at qualitative level, of a metaproteomic analysis performed at relevant moments of the acetification cycle (end of fast and discontinuous loading phases and just prior to unloading phase), it is aimed to investigate the microbiota existent in alcohol wine vinegar as well as its changes during the cycle; to our knowledge, this is the first metaproteomics report carried out in this way on this system. A total of 1723 proteins from 30 different genera were identified; 1615 out of 1723 proteins (93.73%) belonged to the four most frequent (%) genera: Acetobacter, Gluconacetobacter, Gluconobacter and Komagataeibacter. Around 80% of identified proteins belonged to the species Komagataeibacter europaeus. In addition, GO Term enrichment analysis highlighted the important role of catalytic activity, organic cyclic compound binding, metabolic and biosynthesis processes throughout acetic acid fermentation. These findings provide the first step to obtain an AAB profile at omics level related to the environmental changes produced during the typical semi-continuous cycles used in this process and it would contribute to the optimization of operating conditions and improving the industrial production of vinegar.


Assuntos
Ácido Acético/metabolismo , Acetobacter/metabolismo , Reatores Biológicos/microbiologia , Gluconacetobacter/metabolismo , Gluconobacter/metabolismo , Acetobacter/genética , Biodiversidade , Etanol/metabolismo , Fermentação/fisiologia , Gluconacetobacter/genética , Gluconobacter/genética , Microbiota/genética , Vinho/microbiologia
7.
Can J Microbiol ; 66(11): 653-663, 2020 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-32511936

RESUMO

The dependence of plant health and crop quality on the epiphytic microbial community has been extensively addressed, but little is known about plant-associated microbial communities under natural conditions. In this study, the bacterial and fungal communities on grape leaves were analyzed by 16S rRNA gene and internal transcribed spacer high-throughput sequencing, respectively. The results showed differences in the composition of the microbial communities on leaf samples of nine wine grape varieties. The most abundant bacterial genus was Pseudomonas, and the top three varieties with Pseudomonas were Zinfandel (22.6%), Syrah (21.6%), and Merlot (13.5%). The most abundant fungal genus was Alternaria, and the cultivar with the lowest abundance of Alternaria was Zinfandel (33.6%), indicating that these communities had different habitat preferences. The linear discriminant analysis effect size of all species showed that the bacteria Enterococcus, Massilia, and Kocuria were significantly enriched on the leaves of Merlot, Syrah, Cabernet Sauvignon, respectively; Pseudomonadales and Pantoea on Zinfandel; and Bacillus, Turicibacter, and Romboutsia on Pinot Noir. Similarly, the fungi Cladosporium, Phoma, and Sporormiella were significantly enriched on Zinfandel, Lon, and Gem, respectively. Both Bray-Curtis and unweighted UniFrac revealed that bacteria and fungi have a significant impact (P < 0.01), and the results further proved that variety is the most important factor affecting the microbial community. The findings indicate that some beneficial or harmful microorganisms existing on the wine grape leaves might affect the health of the grape plants and the wine-making process.


Assuntos
Microbiota , Vitis/microbiologia , Bactérias/classificação , Bactérias/genética , Bactérias/isolamento & purificação , DNA Espaçador Ribossômico/genética , Fungos/classificação , Fungos/genética , Fungos/isolamento & purificação , Especificidade de Hospedeiro , Folhas de Planta/genética , Folhas de Planta/microbiologia , RNA Ribossômico 16S/genética , Vitis/genética , Vinho/classificação , Vinho/microbiologia
8.
Int J Food Microbiol ; 329: 108651, 2020 Sep 16.
Artigo em Inglês | MEDLINE | ID: mdl-32512285

RESUMO

In Latin, 'pulcherrima' is a superlative form of an adjective that translates as beautiful. Apart from being 'the most beautiful' yeast, Metschnikowia pulcherrima has a remarkable potential in production of wines with lower ethanol content. The oenological performance of six M. pulcherrima strains was hereby tested in sequential cultures with Saccharomyces cerevisiae. The best-performing strain MP2 was further characterised in fermentations with different S. cerevisiae inoculation delays in both white grape juice and Chemically Defined Grape Juice Medium (CDGJM). The analysis of main metabolites, undertaken prior to sequential inoculations and upon fermentation completion, highlighted metabolic interactions and carbon sinks other than ethanol in MP2 treatments. Depending on the inoculation delay, MP2 white wines contained between 0.6% and 1.2% (v/v) less ethanol than the S. cerevisiae monoculture, with even larger decreases detected in the CDGJM. The MP2 treatments also contained higher concentrations of TCA cycle by-products (i.e. fumarate and succinate) and glycerol, and lower concentrations of acetic acid. The analysis of volatile compounds showed increased production of acetate esters and higher alcohols in all MP2 wines, alongside other compositional alterations arising from the S. cerevisiae inoculation delay.


Assuntos
Fermentação , Microbiologia de Alimentos/métodos , Metschnikowia/metabolismo , Saccharomyces cerevisiae/metabolismo , Vinho/microbiologia , Ácido Acético/metabolismo , Etanol/metabolismo , Glicerol/metabolismo , Fatores de Tempo , Vitis/metabolismo , Vitis/microbiologia , Vinho/análise
9.
Appl Environ Microbiol ; 86(17)2020 08 18.
Artigo em Inglês | MEDLINE | ID: mdl-32591381

RESUMO

The use of exogenous functional microorganisms to regulate biogenic amine (BA) content is a common approach in fermentation systems. Here, to better understand the microbial traits of succession trajectories in resource-based and biotic interference systems, the BA-related primary and secondary succession were tracked during industrial semidry Chinese rice wine (CRW) fermentation. Dominant abundance and BA-associated microbial functionality based on phylogenetic investigation of communities by reconstruction of unobserved states (PICRUSt) indicated that Citrobacter, Acinetobacter, Lactobacillus, Exiguobacterium, Bacillus, Pseudomonas, and Enterobacter spp. prominently contributed to the decarboxylase gene family in CRW. The expression levels of tyrosine decarboxylase (tyrDC), ornithine decarboxylase (odc), and agmatine deiminase (aguA) genes were assessed by quantitative PCR (qPCR). The transcription levels of these genes did not correlate with the BA formation rate during postfermentation, indicating that acidification and carbon source depletion upregulated the expression and microbes launch the dormancy strategy to respond to unfavorable conditions. Furthermore, microbial interference with CRW fermentation by Lactobacillus plantarum (ACBC271) and Staphylococcus xylosus (CGMCC1.8382) coinoculated at a ratio of 1:2 exhibited the best synergetic control of BA content. Spearman correlations revealed that Lactobacillus and Staphylococcus exhibited influence on BA-associated microbiota (|ρ| > 0), Exiguobacterium and Pseudomonas were strongly suppressed by Lactobacillus (ρ = -0.867 and ρ = -0.782, respectively; P < 0.05), and Staphylococcus showed the strongest inhibitory effect toward Lactobacillus (ρ = -0.115) and Citrobacter (ρ = -0.188) in the coinoculated 1:2 group. The high inhibitory effect of exogenous added strains on specific bacteria presented evidence for the obtained BA-associated contributors. Overall, this work provides important insight into the microbial traits that rely on resource usage and functional microbiota within food microbial ecology.IMPORTANCE Understanding the shifting patterns of substance usage and microbial interactions is a fundamental objective within microbiology and ecology. Analyses of primary and secondary microbial succession allow for determinations of taxonomic diversity, community traits, and functional transformations over time or after a disturbance. The kinetics of BA generation and the patterns of resource consumption, functional metagenome prediction, and microbial interactions were profiled to elucidate the equilibrium mechanism of microbial systems. Secondary succession after a disturbance triggers a change in resource usage, which in turn affects primary succession and metabolism. In this study, the functional potential of exogenous microorganisms under disturbance synergized with secondary succession strategies, including rebalancing and dormancy, which ultimately reduced BA accumulation. Thus, this succession system could facilitate the settling of essential issues with respect to microbial traits that rely on resource usage and microbial interactions that occur in natural ecosystems.


Assuntos
Aminas Biogênicas/metabolismo , Fermentação , Microbiota/fisiologia , Vinho/microbiologia , Bactérias/isolamento & purificação , China
10.
Int J Food Microbiol ; 331: 108714, 2020 Oct 16.
Artigo em Inglês | MEDLINE | ID: mdl-32544792

RESUMO

Microbiological contamination by spoilage yeasts species are frequent during winemaking, and biological control using antagonistic yeasts is considered a more beneficial alternative to conventional synthetic antimicrobials. Saccharomyces eubayanus killer toxin (SeKT) was produced and purified in a synthetic optimized medium. Purification procedure allowed the identification of SeKT as protein with an apparent molecular mass of 70 kDa and activity at physicochemical conditions suitable for winemaking process. Purified SeKT reduced the levels of volatile phenols produced by the spoilage yeasts Brettanomyces bruxellensis, Pichia membranifaciens, Meyerozyma guilliermondii and Pichia manshurica in wine-like medium. The putative mode of action of SeKT on sensitive yeast strains comprises cell wall disruption through ß-glucanase and chitinase activities as well as necrotic and apoptotic death in a toxin dose dependent manner. Thus, SeKT appears to be a promising biocontrol agent against spoilage yeasts during wine aging and storing.


Assuntos
Microbiologia de Alimentos , Micotoxinas/química , Micotoxinas/toxicidade , Saccharomyces/química , Vinho/microbiologia , Parede Celular/efeitos dos fármacos , Micotoxinas/isolamento & purificação , Fenóis/metabolismo , Saccharomyces/metabolismo , Leveduras/efeitos dos fármacos
11.
Sci Rep ; 10(1): 7962, 2020 05 14.
Artigo em Inglês | MEDLINE | ID: mdl-32409784

RESUMO

The biodiversity and evolution of fungal communities were monitored over a period of 3 vintages in a new winery. Samples were collected before grape receipt and 3 months after fermentation from 3 different wine related environments (WRE): floor, walls and equipment and analyzed using Illumina Mi-Seq. Genera of mold and filamentous fungi (294), non-enological (10) and wine-associated yeasts (25) were detected on all WREs before the arrival of the first harvest. Among them, genera like Alternaria and Aureobasidium persisted during two vintages. Therefore, these genera are not specific to winery environment and appear to be adapted to natural or anthropic environments due to their ubiquitous character. Some genera like Candida were also detected before the first harvest but only on one WREs, whereas, on the other WREs they were found after the harvest. The ubiquitous character and phenotypic traits of these fungal genera can explain their dynamics. After the first harvest and during 3 vintages the initial consortium was enriched by oenological genera like Starmerella introduced either by harvest or by potential transfers between the different WREs. However, these establishing genera, including Saccharomyces, do not appear to persist due to their low adaptation to the stressful conditions of winery environment.


Assuntos
Fungos/metabolismo , Vinho/microbiologia , Biodiversidade , Evolução Biológica , Fermentação , Fungos/classificação
12.
Int J Food Microbiol ; 324: 108615, 2020 Jul 02.
Artigo em Inglês | MEDLINE | ID: mdl-32371236

RESUMO

In recent years, CRISPR/Cas9-based genetic editing has become a mainstay in many laboratories including manipulations done with yeast. We utilized this technique to generate a self-cloned wine yeast strain that overexpresses two genes of oenological relevance i.e. the glycerol-3-phosphate dehydrogenase 1 (GPD1) and the alcohol acetyltransferase 1 (ATF1) directly implicated in glycerol and acetate ester production respectively. Riesling wine made from the resulting strain showed increased glycerol and acetate ester levels compared to the parental strain. In addition, significantly less acetic acid levels were measured in wine made with yeast containing both genetic alterations compared to wine made with the strain that only overexpresses GPD1. Thus, this strain provides an alternative strategy for alleviating the accumulation of acetic acid once glycerol production is favoured during alcoholic fermentation with the addition of dramatically increasing acetate esters production.


Assuntos
Sistemas CRISPR-Cas , Saccharomyces cerevisiae/genética , Vinho/microbiologia , Ácido Acético/análise , Ácido Acético/metabolismo , Fermentação , Edição de Genes , Glicerol/análise , Glicerol/metabolismo , Glicerol-3-Fosfato Desidrogenase (NAD+)/genética , Glicerol-3-Fosfato Desidrogenase (NAD+)/metabolismo , Fenótipo , Proteínas/genética , Proteínas/metabolismo , Saccharomyces cerevisiae/metabolismo , Proteínas de Saccharomyces cerevisiae/genética , Proteínas de Saccharomyces cerevisiae/metabolismo , Vinho/análise
13.
PLoS One ; 15(5): e0233285, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32453779

RESUMO

Fermentation by microorganisms is a key step in the production of traditional food products such as bread, cheese, beer and wine. In these fermentative ecosystems, microorganisms interact in various ways, namely competition, predation, commensalism and mutualism. Traditional wine fermentation is a complex microbial process performed by Saccharomyces and non-Saccharomyces (NS) yeast species. To better understand the different interactions occurring within wine fermentation, isolated yeast cultures were compared with mixed co-cultures of one reference strain of S. cerevisiae with one strain of four NS yeast species (Metschnikowia pulcherrima, M. fructicola, Hanseniaspora opuntiae and H. uvarum). In each case, we studied population dynamics, resource consumed and metabolites produced from central carbon metabolism. This phenotyping of competition kinetics allowed us to confirm the main mechanisms of interaction between strains of four NS species. S. cerevisiae competed with H. uvarum and H. opuntiae for resources although both Hanseniaspora species were characterized by a strong mortality either in mono or mixed fermentations. M. pulcherrima and M. fructicola displayed a negative interaction with the S. cerevisiae strain tested, with a decrease in viability in co-culture. Overall, this work highlights the importance of measuring specific cell populations in mixed cultures and their metabolite kinetics to understand yeast-yeast interactions. These results are a first step towards ecological engineering and the rational design of optimal multi-species starter consortia using modeling tools. In particular the originality of this paper is for the first times to highlight the joint-effect of different species population dynamics on glycerol production and also to discuss on the putative role of lipid uptake on the limitation of some non-conventional species growth although interaction processes.


Assuntos
Fermentação , Hanseniaspora/metabolismo , Metschnikowia/metabolismo , Saccharomyces cerevisiae/metabolismo , Vinho/microbiologia , Dióxido de Carbono/metabolismo , Fermentação/fisiologia , Frutose/metabolismo , Sucos de Frutas e Vegetais/microbiologia , Glucose/metabolismo , Cinética , Nitrogênio/metabolismo , Vitis
14.
J Biosci Bioeng ; 130(2): 159-165, 2020 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-32418725

RESUMO

Soaking is an important process in Chinese rice wine brewing. In this study, the influence of vacuum soaking on Chinese rice wine production was investigated. Rice subjected to a 1-h vacuum soaking process or a traditional 2-days soaking process was steamed and fermented. Our results showed that vacuum soaking led to similar absorbed water but less leached solids compared with traditional soaking and showed limited influence on the physiochemical characteristics of steamed rice. Monitoring of the fermentation process suggested that the content of amino acid nitrogen in the vacuum-soaked group was significantly higher than that of the traditional-soaked group, while the other indexes were similar. The detection of flavor substances in the rice wine indicated that the contents of organic acids and free amino acids were higher in the vacuum-soaked group, and the main kinds of volatile flavor compounds from the two groups were similar. Additionally, sensory evaluation reflected that the rice wine brewed with rice subjected to either of the two different soaking treatments had similar sensory performances. Our research indicated that vacuum soaking could effectively shorten the soaking time of rice in Chinese rice wine production, thus shortening the brewing cycle without sacrificing the quality of the rice wine.


Assuntos
Manipulação de Alimentos/métodos , Microbiologia Industrial/métodos , Oryza/química , Vapor , Vácuo , Vinho/normas , Ácidos/análise , Fermentação , Aromatizantes/análise , Nitrogênio/análise , Oryza/metabolismo , Paladar , Vinho/microbiologia
15.
Sci Rep ; 10(1): 6676, 2020 04 21.
Artigo em Inglês | MEDLINE | ID: mdl-32317674

RESUMO

Grape-derived proanthocyanidins could act as a protector against various environmental stresses for Saccharomyces cerevisiae during wine fermentation, resulting in the increased physiological activity, fermentation efficiency and improved wine quality. In order to explore the possible protection mechanism of proanthocyanidins globally, RNA-seq analysis for wine yeast AWRI R2 cultivated with 0 g/L (group A), 0.1 g/L (group B), 1.0 g/L (group C) proanthocyanidins were applied in this study. Differentially expressed genes were enriched into six metabolic pathways including vitamin B6, thiamine, amino acids, aminoacyl-tRNA, carbohydrate and steroid based on KEGG enrichment analysis. Four key genes (SNZ2, THI6, THI21 and THI80), participated in the biosynthesis of vitamin B6 and thiamine, were up-regulated significantly in proanthocyanidins treated yeast cells and the gene expression levels were verified by RT-qPCR. Yeast cells supplemented with proanthocyanidins performed increased intracellular levels of vitamin B6 and thiamine and higher cell viability compared to the control group. In addition, the composition of intracellular fatty acids showed an obvious alternation in proanthocyanidins-treated yeast cells, in which the UFAs content increased whereas the SFA content decreased. In general, we provided an indirect protection effect of proanthocyanidins on the yeast cells to alleviate environmental stresses during wine fermentation.


Assuntos
Fermentação/efeitos dos fármacos , Perfilação da Expressão Gênica , Proantocianidinas/farmacologia , Saccharomyces cerevisiae/genética , Saccharomyces cerevisiae/fisiologia , Vinho/microbiologia , Regulação para Baixo/efeitos dos fármacos , Regulação para Baixo/genética , Ácidos Graxos/metabolismo , Fermentação/genética , Regulação Fúngica da Expressão Gênica/efeitos dos fármacos , Ontologia Genética , Redes e Vias Metabólicas/efeitos dos fármacos , Redes e Vias Metabólicas/genética , Viabilidade Microbiana/efeitos dos fármacos , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Saccharomyces cerevisiae/efeitos dos fármacos , Tiamina/metabolismo , Regulação para Cima/efeitos dos fármacos , Regulação para Cima/genética , Vitamina B 6/metabolismo
16.
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
17.
Food Microbiol ; 90: 103467, 2020 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-32336361

RESUMO

Hong Qu glutinous rice wine (HQGRW) is typically very bitter after fermentation due to the presence of bitter amino acids (BAA). The amino acids are considered to primarily derive from the hydrolysis of protein from the raw material by microbial populations during fermentation, and temperature also has an important effect on bitter tastes. Here, the dynamics of fungal and bacterial communities during the traditional fermentation of HQGRW were investigated using high-throughput sequencing and RNA-based rRNA gene sequencing. Both principal component analysis (PCA) and hierarchical clustering analysis (HCA) revealed significant differences between the fungal and bacterial communities during fermentation at 20 °C and those performed at 25 °C and 30 °C. The growth of Saccharomyces and some LAB apparently inhibited the growth of several pernicious bacterial taxa including acetic acid bacteria. The amino acid contents of the samples all increased continuously under the different temperature conditions. Moreover, higher temperatures were associated with higher perceptual intensity of bitterness and contents of amino acids including bitter, sweet, umami, and astringent type amino acids as well as the total amino acid content during fermentation. Furthermore, the total BAA content was strongly and positively correlated with Pediococcus, Saccharomyces, Lactobacillus, Monascus, and Halomonas relative abundances, with correlations identified by |r| > 0.6 with P adjusted P < 0.05. In conclusion, these results contribute to a better understanding of the mechanisms underlying BAA production during the traditional fermentation of HQGRW and will help improve the quality and safety of these wines.


Assuntos
Aminoácidos/metabolismo , Bactérias/metabolismo , Fermentação , Microbiota , Oryza/microbiologia , Vinho/microbiologia , Bactérias/classificação , Bactérias/isolamento & purificação , Fungos/isolamento & purificação , Fungos/metabolismo , Temperatura
18.
Food Microbiol ; 90: 103451, 2020 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-32336373

RESUMO

Aureobasidium pullulans has been observed as one of the most abundant species in freshly pressed grape juice. Despite this, little is known about the consequences for the wine-making process associated with the presence and proliferation of this fungus, including its interaction with other ferment-derived microorganisms and impact on the composition of the resulting wine. In this study, the physiology of abundant A. pullulans grape juice isolates was investigated through lab scale fermentation trials, demonstrating the ability of this species to survive in grape juice while producing polysaccharides, polymers of malic acid (poly ß-malic acid) and enzymes with pectinase, ß - glucosidase and tannase activity. A possible antagonistic effect against yeast through competition for metals including Fe and Zn was also observed. Overall, the data suggests this abundant species could have important implications for wine production and quality.


Assuntos
Ascomicetos/fisiologia , Fermentação , Sucos de Frutas e Vegetais/análise , Sucos de Frutas e Vegetais/microbiologia , Vitis/microbiologia , Ascomicetos/enzimologia , Hidrolases de Éster Carboxílico/biossíntese , Polissacarídeos Fúngicos/biossíntese , Ferro/metabolismo , Poligalacturonase/biossíntese , Vinho/microbiologia , Zinco/metabolismo , beta-Glucosidase/biossíntese
19.
Food Microbiol ; 90: 103483, 2020 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-32336374

RESUMO

Sulfur dioxide is generally used as an antimicrobial in wine to counteract the activity of spoilage yeasts, including Brettanomyces bruxellensis. However, this chemical does not exert the same effectiveness on different B. bruxellensis yeasts since some strains can proliferate in the final product leading to a negative sensory profile due to 4-ethylguaiacol and 4-ethylphenol. Thus, the capability of deciphering the general molecular mechanisms characterizing this yeast species' response in presence of SO2 stress could be considered strategic for a better management of SO2 in winemaking. A RNA-Seq approach was used to investigate the gene expression of two strains of B. bruxellensis, AWRI 1499 and CBS 2499 having different genetic backgrounds, when exposed to a SO2 pulse. Results revealed that sulphites affected yeast culturability and metabolism, but not volatile phenol production suggesting that a phenotypical heterogeneity could be involved for the SO2 cell adaptation. The transcriptomics variation in response to SO2 stress confirmed the strain-related response in B. bruxellensis and the GO analysis of common differentially expressed genes showed that the detoxification process carried out by SSU1 gene can be considered as the principal specific adaptive response to counteract the SO2 presence. However, nonspecific mechanisms can be exploited by cells to assist the SO2 tolerance; namely, the metabolisms related to sugar alcohol (polyols) and oxidative stress, and structural compounds.


Assuntos
Brettanomyces/genética , Brettanomyces/metabolismo , Fermentação , Estresse Fisiológico , Dióxido de Enxofre/metabolismo , Vinho/microbiologia , Microbiologia de Alimentos , Perfilação da Expressão Gênica , RNA-Seq , Transcriptoma
20.
Food Microbiol ; 90: 103460, 2020 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-32336379

RESUMO

The use of Saccharomyces and non-Saccharomyces yeast species as mixed starters has potential advantages over pure culture fermentation due to increased wine complexity based on modification of metabolites of oenological interest. In this work, the effects of initial oxygenation on fermentation performance, chemical and volatile composition of French Colombard wine fermented with Hanseniaspora vineae and Saccharomyces cerevisiae in sequential inoculations were investigated in 1 L flasks. Although dominated by S. cerevisiae at the middle-end of fermentation, initial aeration for 1 day boosted H. vineae populations, and allowed H. vineae to coexist longer with S. cerevisiae in mixed cultures compared to no aeration, and suppressed S. cerevisiae later in the fermentation, which resulted in extended fermentation time. More important, the major fermentation products and volatile compounds were significantly modified by aeration and different from no aeration fermentation. The wines produced by aeration of mixed fermentations were characterized with higher amounts of glycerol, lactic acid and acetate esters, and lower levels of ethanol, higher alcohol and ethyl fatty acid esters. The aeration had more potential to shape the quality of wines and diversify the aromatic characteristics relative to simple mixed inoculation, as indicated by PCA analysis. Our results suggested that the impact of early aeration on yeast physiology extends beyond the aeration phase and influences fermentation activity, chemical and aromatic compounds in the following anaerobic stage. The aeration for a short time during the cell growth stage in mixed fermentation is therefore a potential means to increase the aromatic diversity and quality of wine, possibly providing an alternative approach to meet the expectations of wine consumers for diverse aromatic qualities.


Assuntos
Fermentação , Hanseniaspora/metabolismo , Oxigênio/metabolismo , Saccharomyces cerevisiae/metabolismo , Vinho/análise , Vinho/microbiologia , Álcoois/análise , Etanol/análise , Glicerol/análise , Ácido Láctico/análise , Odorantes/análise
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