scholarly journals Biodiversity among Brettanomyces bruxellensis Strains Isolated from Different Wine Regions of Chile: Key Factors Revealed about Its Tolerance to Sulphite

2020 ◽  
Vol 8 (4) ◽  
pp. 557
Author(s):  
Camila G-Poblete ◽  
Irina Charlot Peña-Moreno ◽  
Marcos Antonio de Morais ◽  
Sandra Moreira ◽  
María Angélica Ganga
Keyword(s):  
Protective Action ◽  
Wine Industry ◽  
Acid Decarboxylase ◽  
Decarboxylase Activity ◽  
Coumaric Acid ◽  
Key Factors ◽  
Volatile Phenols ◽  
Brettanomyces Bruxellensis ◽  
Adverse Environmental Conditions ◽  
First Time

Brettanomyces bruxellensis is regarded as the main spoilage microorganism in the wine industry, owing to its production of off-flavours. It is difficult to eradicate owing to its high tolerance of adverse environmental conditions, such as low nutrient availability, low pH, and high levels of ethanol and SO2. In this study, the production of volatile phenols and the growth kinetics of isolates from various regions of Chile were evaluated under stressful conditions. Through randomly amplified polymorphic DNA (RAPD) analysis, 15 strains were identified. These were grown in the presence of p-coumaric acid, a natural antimicrobial and the main precursor of off-flavours, and molecular sulfur dioxide (mSO2), an antimicrobial synthetic used in the wine industry. When both compounds were used simultaneously, there were clear signs of an improvement in the fitness of most of the isolates, which showed an antagonistic interaction in which p-coumaric acid mitigates the effects of SO2. Fourteen strains were able to produce 4-vinylphenol, which showed signs of phenylacrylic acid decarboxylase activity, and most of them produced 4-ethylphenol as a result of active vinylphenol reductase. These results demonstrate for the first time the serious implications of using p-coumaric acid, not only for the production of off-flavours, but also for its protective action against the toxic effects of SO2.

scholarly journals Effect of Light and p-Coumaric Acid on the Growth and Expression of Genes Related to Oxidative Stress in Brettanomyces bruxellensis LAMAP2480

2021 ◽  
Vol 12 ◽  
Author(s):  
Daniela Catrileo ◽  
Sandra Moreira ◽  
María Angélica Ganga ◽  
Liliana Godoy
Keyword(s):  
Oxidative Stress ◽  
Antimicrobial Properties ◽  
Growth Curves ◽  
Wine Industry ◽  
Economic Losses ◽  
Protective Effects ◽  
Coumaric Acid ◽  
Volatile Phenols ◽  
Brettanomyces Bruxellensis ◽  
Expression Of Genes

Brettanomyces bruxellensis is considered the most significant contaminant yeast in the wine industry since it causes a deterioration in the organoleptic properties of the wine and significant economic losses. This deterioration is due to the production of volatile phenols from hydroxycinnamic acids. These compounds possess antimicrobial properties; however, B. bruxellensis can resist this effect because it metabolizes them into less toxic ones. Recent studies have reported that B. bruxellensis grows under different stress conditions, including p-coumaric acid (pCA) but effective methods for its control have not been found yet. Since that in other yeasts, such as Saccharomyces cerevisiae, it has been described that light affects its growth, and we evaluated whether the light would have a similar effect on B. bruxellensis. The results show that at light intensities of 2,500 and 4,000 lux in the absence of pCA, B. bruxellensis LAMAP2480 does not grow in the culture medium; however, when the medium contains this acid, the yeast adapts to both factors of stress managing to grow. The expression of genes related to oxidative stress in B. bruxellensis LAMAP2480, such as SOD1, GCN4, and ESBP6, showed a higher relative expression when the yeast was exposed to 2,500 lux compared to 4,000 lux, agreeing with the growth curves. This suggests that a higher expression of the genes studied would be related to stress-protective effects by pCA.

scholarly journals Microbiological, biochemical, physicochemical surface properties and biofilm forming ability of Brettanomyces bruxellensis

2019 ◽  
Author(s):  
Maria Dimopoulou ◽  
Margareth Renault ◽  
Marguerite Dols-Lafargue ◽  
Warren Albertin-Leguay ◽  
Jean-Marie Herry ◽  
...  
Keyword(s):  
Surface Properties ◽  
Biofilm Formation ◽  
Yeast Species ◽  
Economic Loss ◽  
Wine Industry ◽  
Yeast Cells ◽  
Volatile Phenols ◽  
Brettanomyces Bruxellensis ◽  
Wine Spoilage ◽  
Strain Dependent

AbstractBrettanomyces bruxellensis is a serious source of concern for winemakers. The production of volatile phenols by the yeast species confers to wine unpleasant sensory characteristics which are unacceptable by the consumers and inevitably provoke economic loss for the wine industry. This ubiquitous yeast is able to adapt to all winemaking steps and to withstand various environmental conditions. Moreover, the ability of B. bruxellensis to adhere and colonize inert materials can be the cause of the yeast persistence in the cellars and thus recurrent wine spoilage. We therefore investigated the surface properties, biofilm formation capacity and the factors which may affect the attachment of the yeast cells to surfaces with eight strains representative of the genetic diversity of the species. Our results show that the biofilm formation ability is strain-dependent and suggest a possible link between the physicochemical properties of the studied strains and their corresponding genetic group.

scholarly journals Knockout of the p-Coumarate Decarboxylase Gene from Lactobacillus plantarum Reveals the Existence of Two Other Inducible Enzymatic Activities Involved in Phenolic Acid Metabolism

2000 ◽  
Vol 66 (8) ◽  
pp. 3368-3375 ◽  
Author(s):  
Lise Barthelmebs ◽  
Charles Divies ◽  
Jean-François Cavin
Keyword(s):  
Ferulic Acid ◽  
Lactobacillus Plantarum ◽  
Specific Activity ◽  
Reductase Activity ◽  
Enzymatic Activities ◽  
Gene Copy ◽  
Acid Decarboxylase ◽  
Decarboxylase Activity ◽  
Coumaric Acid

ABSTRACT Lactobacillus plantarum NC8 contains a pdcgene coding for p-coumaric acid decarboxylase activity (PDC). A food grade mutant, designated LPD1, in which the chromosomalpdc gene was replaced with the deleted pdc gene copy, was obtained by a two-step homologous recombination process using an unstable replicative vector. The LPD1 mutant strain remained able to weakly metabolize p-coumaric and ferulic acids into vinyl derivatives or into substituted phenyl propionic acids. We have shown that L. plantarum has a second acid phenol decarboxylase enzyme, better induced with ferulic acid than withp-coumaric acid, which also displays inducible acid phenol reductase activity that is mostly active when glucose is added. Those two enzymatic activities are in competition for p-coumaric and ferulic acid degradation, and the ratio of the corresponding derivatives depends on induction conditions. Moreover, PDC appeared to decarboxylate ferulic acid in vitro with a specific activity of about 10 nmol · min−1 · mg−1 in the presence of ammonium sulfate. Finally, PDC activity was shown to confer a selective advantage on LPNC8 grown in acidic media supplemented withp-coumaric acid, compared to the LPD1 mutant devoid of PDC activity.

The Sayan borderlands: Tuva’s ethnocultural landscapes in changing natural and sociocultural environments

2020 ◽  
Vol 13 (1) ◽  
pp. 29-36
Author(s):  
D. A. Dirin ◽  
Paul Fryer
Keyword(s):  
Cultural Landscapes ◽  
Field Studies ◽  
Social Environments ◽  
Key Factors ◽  
Role Of Government ◽  
Literary Sources ◽  
Population Migrations ◽  
The Republic ◽  
Sociocultural Processes ◽  
First Time

The paper is devoted to ethno-cultural landscapes of the Republic of Tuva. Ethnocultural landscapes (ECLs) are specific socio-environmental systems that developed as a result of the interaction of ethnic groups with their natural and social environments and are in a constant process of transformation. An attempt is made to identify the mechanisms of the formation, functioning and dynamics of ethnocultural landscapes in the specific conditions of the intracontinental cross-border mountain region, as well as to establish the main factors-catalysts of their modern changes. For the first time an attempt is made to delimit and map the ethnocultural landscapes of Tuva. For this, literary sources, statistical data and thematic maps of different times are analyzed using geoinformation methods. The results of 2014-2018 field studies are also used, during which interviews with representatives of different ethno-territorial, gender, age and social groups were taken. It is revealed that the key factors of Tuva’s ethnocultural landscape genesis are the natural isolation of its territory; the features of its landscape structure; the role of government; population migrations from other regions and the cultural diffusion provoked by them. 13 ethnocultural landscapes are identified at the regional level. Their modern transformation is determined by the shift of climatic cycles, aridisation, globalisation of sociocultural processes, changes in economic specialisation and ethnopsychological stereotypes.

α-Glucosidase Inhibition and Docking Studies of 5-Deoxyflavonols and Dihydroflavonols Isolated from Abutilon pakistanicum

2019 ◽  
Vol 23 (17) ◽  
pp. 1857-1866
Author(s):  
Munawar Hussain ◽  
Zaheer Ahmed ◽  
Shamsun N. Khan ◽  
Syed A. A. Shah ◽  
Rizwana Razi ◽  
...  
Keyword(s):  
Methanolic Extract ◽  
Docking Studies ◽  
Hydroxyl Group ◽  
Coumaric Acid ◽  
In Vitro Activity ◽  
Aerial Parts ◽  
First Time ◽  
Acid Esters ◽  
Phenol Moiety

Three new 5-deoxyflavonoid and dihydroflavonoids 2, 3 and 4 have been isolated from the methanolic extract of Abutioln pakistanicum aerial parts, for which structures were elucidated explicitly by extensive MS- and NMR-experiments. In addition to these, 3,7,4′-trihydroxy-3′-methoxy flavonol (1) is reported for the first time from Abutioln pakistanicum. Compound 2 and 4 are p-coumaric acid esters while compounds 2–4 exhibited α-glucosidase inhibitory activity. Docking studies indicated that the ability of flavonoids 2, 3 and 4 to form multiple hydrogen bonds with catalytically important residues is decisive hence is responsible for the inhibition activity. The docking results signified the observed in-vitro activity quite well which is in accordance with previously obtained conclusion that phenol moiety and hydroxyl group are critical for the inhibition of α-glucosidase enzyme.

Improving the Strength of Abrasive Wheels and Optimizing the Control over the Strength of Composite Abrasive Materials

2019 ◽  
Vol 946 ◽  
pp. 380-385
Author(s):  
Boris A. Chaplygin ◽  
Viacheslav V. Shirokov ◽  
Tat'yana A. Lisovskaya ◽  
Roman A. Lisovskiy
Keyword(s):  
Mechanical Properties ◽  
Test Results ◽  
Key Factors ◽  
Special Equipment ◽  
Material Density ◽  
Factors Affecting ◽  
Control Factors ◽  
Reinforcing Material ◽  
Special Studies ◽  
First Time

The strength of abrasive wheels is one of the key factors affecting the performance of abrasive machining. The paper discusses ways to improve the strength of abrasive wheels. The stress-state mathematical model presented herein is a generalization of the existing models. It is used herein to find for the first time that there are numerous optimal combinations of the elastic modulus and reinforcing material density, which result in the same minimum value of the objective function. It is found out that increasing the radius of the reinforcing component while also optimizing the mechanical properties of its material may increase the permissible breaking speed of the wheel several times. We herein present a regression equation and a nomogram for finding the optimal combination of control factors. Conventional methods for testing the mechanical properties of materials, which have been proven reliable for testing metals and alloys, are not as reliable for testing abrasive materials, as the test results they generate are not sufficiently stable or accurate. We therefore propose an alternative method that does not require any special equipment or special studies.

Abstract 110: Adiponectin Inhibits TNF-a-Induced Vascular Inflammatory Response via Caveolin-Mediated Ceramidase Recruitment and Activation

2013 ◽  
Vol 113 (suppl_1) ◽  
Author(s):  
Yajing Wang ◽  
Wayne Lau ◽  
Erhe Gao ◽  
Walter Koch ◽  
Xin Ma
Keyword(s):  
Inflammatory Response ◽  
Protective Action ◽  
Receptor Subtype ◽  
Protective Actions ◽  
Nitrative Stress ◽  
S1p Receptor ◽  
Anti Inflammatory ◽  
Or Gene ◽  
First Time

Anti-inflammatory and vascular protective actions of adiponectin (APN) are well-recognized. However, many fundamental questions remain unanswered. The current study attempted to identify the APN receptor subtype responsible for APN’s vascular protective action, and investigate the role of ceramidase activation in APN anti-inflammatory signaling. Wild type (WT) or gene manipulated HUVEC were treated with TNFα in the presence and absence of APN. The effect of APN on TNFα-induced inflammatory and oxidative/nitrative stress was determined. In WT HUVEC, APN significantly reduced TNFα-induced ICAM-1 expression and attenuated TNFα-induced superoxide and peroxynitrite formation (P<0.01). These anti-inflammatory actions were virtually abolished by AdipoR1-, but not AdipoR2-, knockdown (KD). Treatment with APN significantly increased neutral ceramidase (nCDase) activity (3.7-fold, P<0.01). AdipoR1-KD markedly (P0.05), reduced APN-induced nCDase activation. More importantly, siRNA mediated nCDase-KD markedly blocked the effect of APN upon TNFα-induced ICAM-1 expression (P0.05), and modestly inhibited APN anti-inflammatory effect (P87% of APN-induced nCDase activation was lost. Whereas APN treatment failed to inhibit TNFα-induced ICAM-1 expression, treatment with S1P or SEW (S1P receptor agonist) remained effective in Cav1-KD cells in reducing TNFα-induced ICAM-1 expression (P<0.01). AdipoR1 and Cav1 co-localized and co-precipitated in HUVECs. APN treatment did not affect this interaction. Moreover, re-expression of WT Cav1 in Cav1-KD cells restored nCDase activation in response to APN (P<0.01 vs. vehicle), whereas re-expression of a mutated Cav1 blocking AdipoR1/Cav1 interaction failed to restore APN-mediated nCDase activation. Finally, there is weak basal Cav1/nCDase interaction, which significantly increased following APN treatment. These results demonstrate for the first time that APN inhibits TNFα-induced inflammatory response via Cav1-mediated ceramidase recruitment and activation in an AdipoR1- dependent fashion.

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