scholarly journals Effect of sulfite addition and pied de cuve inoculation on the microbial communities and sensory profiles of Chardonnay wines: dominance of indigenous Saccharomyces uvarum at a commercial winery

2019 ◽  
Vol 19 (5) ◽  
Author(s):  
Sydney C Morgan ◽  
Garrett C McCarthy ◽  
Brittany S Watters ◽  
Mansak Tantikachornkiat ◽  
Ieva Zigg ◽  
...  
Keyword(s):  
Bacterial Communities ◽  
Alcoholic Fermentation ◽  
Indigenous Population ◽  
Microbial Consortium ◽  
Grape Juice ◽  
Malolactic Fermentation ◽  
Fungal Communities ◽  
Saccharomyces Uvarum ◽  
Culture Independent ◽  
Sensory Profiles

ABSTRACT 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.

scholarly journals In ovo microbial communities: a potential mechanism for the initial acquisition of gut microbiota among oviparous birds and lizards

2018 ◽  
Vol 14 (7) ◽  
pp. 20180225 ◽  
Author(s):  
Brian K. Trevelline ◽  
Kirsty J. MacLeod ◽  
Sarah A. Knutie ◽  
Tracy Langkilde ◽  
Kevin D. Kohl
Keyword(s):  
Gut Microbiota ◽  
Microbial Communities ◽  
Bacterial Communities ◽  
Reproductive Tract ◽  
Egg Yolk ◽  
Fungal Communities ◽  
In Ovo ◽  
Physiological Processes ◽  
Initial Acquisition ◽  
Culture Independent

Vertebrate gut microbiota mediate critical physiological processes known to affect host fitness, but the mechanisms that expose wildlife to pioneer members of this important microbial community are not well understood. For example, oviparous vertebrates are thought to acquire gut microbiota through post-natal exposure to the external environment, but recent evidence from placental mammals suggests that the vertebrate reproductive tract harbours microbiota that may inoculate offspring in utero . These findings suggest that oviparous vertebrates may be capable of acquiring pioneer microbiota in ovo , but this phenomenon remains unexplored. To fill this knowledge gap, we used culture-independent inventories to determine if the eggs of wild birds and lizards harboured in ovo microbial communities. Our approach revealed distinct in ovo bacterial communities, but fungal communities were indistinguishable from controls. Further, lizard eggs from the same clutch had bacterial community structures that were more similar to each other than to unrelated individuals. These results suggest that oviparous vertebrates may acquire maternal microbiota in ovo , possibly through the inoculation of egg yolk prior to shelling. Therefore, this study may provide a first glimpse of a phenomenon with substantial implications for our understanding of the ecological and evolutionary factors shaping gut microbial communities.

scholarly journals The effect of grape juice dilution on oenological fermentation

2020 ◽  
Author(s):  
Jennifer Margaret Gardner ◽  
Michelle Elisabeth Walker ◽  
Paul Kenneth Boss ◽  
Vladimir Jiranek
Keyword(s):  
Alcoholic Fermentation ◽  
Grape Juice ◽  
Malolactic Fermentation ◽  
Isoamyl Acetate ◽  
List Type ◽  
Water Addition ◽  
Wine Flavour ◽  
Wine Volatiles ◽  
The Impact ◽  
Complex Organic

AbstractThe impact of water addition to grape juice in winemaking, on both alcoholic and malolactic fermentation duration and outcome has been examined using commercial wine yeasts, Lalvin EC1118™ and Lalvin R2™ and malolactic bacteria Lalvin VP41™. As expected, dilution with water did not impede fermentation, instead resulted in shortened duration, or in the case of malolactic fermentation enabled completion in these conditions. Addition of complex organic nutrient further shortened alcoholic fermentation by Lalvin R2™ and in some conditions also reduced the duration of malolactic fermentation. In general, volatile compounds and some major yeast metabolites were present at lower concentrations at the end of fermentation where juices were diluted and the addition of organic complex nutrient also influenced the concentration of some compounds in wine. These findings are significant to commercial winemaking, highlighting that winemakers should consider potential impacts of juice dilution on processing efficiencies along with wine flavour and aroma.Highlights: Gardner et al. The effect of grape juice dilution on fermentationGrape juice dilution shortened both alcoholic and malolactic fermentationIn some conditions addition of commercial nutrient decreased fermentation durationIn general wine volatiles decrease with grape juice dilutionIsoamyl acetate can be decreased in wine by grape juice dilution

scholarly journals Use of Yeast Mannoproteins by Oenococcus oeni during Malolactic Fermentation under Different Oenological Conditions

Foods ◽  
2021 ◽  
Vol 10 (7) ◽  
pp. 1540
Author(s):  
Aitor Balmaseda ◽  
Laura Aniballi ◽  
Nicolas Rozès ◽  
Albert Bordons ◽  
Cristina Reguant
Keyword(s):  
Energy Source ◽  
Nutrient Medium ◽  
Alcoholic Fermentation ◽  
Hydrolytic Activity ◽  
Malolactic Fermentation ◽  
Oenococcus Oeni ◽  
Consumption Patterns ◽  
Inhibitor Compounds

Oenococcus oeni is the main agent of malolactic fermentation in wine. This fermentation takes place after alcoholic fermentation, in a low nutrient medium where ethanol and other inhibitor compounds are present. In addition, some yeast-derived compounds such as mannoproteins can be stimulatory for O. oeni. The mannoprotein concentration in wine depends on the fermenting yeasts, and non-Saccharomyces in particular can increase it. As a result of the hydrolytic activity of O. oeni, these macromolecules can be degraded, and the released mannose can be taken up and used as an energy source by the bacterium. Here we look at mannoprotein consumption and the expression of four O. oeni genes related to mannose uptake (manA, manB, ptsI, and ptsH) in a wine-like medium supplemented with mannoproteins and in natural wines fermented with different yeasts. We observe a general gene upregulation in response to wine-like conditions and different consumption patterns in the studied media. O. oeni was able to consume mannoproteins in all the wines. This consumption was notably higher in natural wines, especially in T. delbrueckii and S. cerevisiae 3D wines, which presented the highest mannoprotein levels. Regardless of the general upregulation, it seems that mannoprotein degradation is more closely related to the fermenting medium.

Integration of culture-dependent and independent methods provides a more coherent picture of the pig gut microbiome

2020 ◽  
Vol 96 (3) ◽  
Author(s):  
Gavin J Fenske ◽  
Sudeep Ghimire ◽  
Linto Antony ◽  
Jane Christopher-Hennings ◽  
Joy Scaria
Keyword(s):  
Bacterial Communities ◽  
Bacterial Species ◽  
Shotgun Metagenomics ◽  
Culture Techniques ◽  
Microbiome Composition ◽  
Culture Independent ◽  
Health And Disease ◽  
The Media ◽  
And Function ◽  
Culture Dependent

ABSTRACT Bacterial communities resident in the hindgut of pigs, have profound impacts on health and disease. Investigations into the pig microbiome have utilized either culture-dependent, or far more commonly, culture-independent techniques using next generation sequencing. We contend that a combination of both approaches generates a more coherent view of microbiome composition. In this study, we surveyed the microbiome of Tamworth breed and feral pigs through the integration high throughput culturing and shotgun metagenomics. A single culture medium was used for culturing. Selective screens were added to the media to increase culture diversity. In total, 46 distinct bacterial species were isolated from the Tamworth and feral samples. Selective screens successfully shifted the diversity of bacteria on agar plates. Tamworth pigs are highly dominated by Bacteroidetes primarily composed of the genus Prevotella whereas feral samples were more diverse with almost equal proportions of Firmicutes and Bacteroidetes. The combination of metagenomics and culture techniques facilitated a greater retrieval of annotated genes than either method alone. The single medium based pig microbiota library we report is a resource to better understand pig gut microbial ecology and function. It allows for assemblage of defined bacterial communities for studies in bioreactors or germfree animal models.

scholarly journals Results Concerning the Evolution of Bacterial Population during the Malolactic Fermentation

1970 ◽  
Vol 66 (2) ◽  
Author(s):  
Ionel POPESCU-MITROI ◽  
Marin GHEORGHIŢĂ ◽  
Felicia STOICA
Keyword(s):  
Bacterial Population ◽  
Alcoholic Fermentation ◽  
Malolactic Fermentation ◽  
Bacterial Density ◽  
Red Wines ◽  
Decline Phase ◽  
Population Evolution ◽  
Counting Methods ◽  
Direct Counting ◽  
Lactic Bacteria

During this experiment, the evolution of inner lactic bacteria microflora was monitored, during a spontaneous and conducted malolactic fermentation developed in the fall of the year 2006 at red wines obtained in Minis – Maderat wine yard. Thereby was monitored the bacterial population evolution, immediately after finishing the alcoholic fermentation (before developing the malolactic fermentation), through standard cultural method and through direct counting methods (counting with Thoma board and counting through Breed method). Results show that wines, at the end of alcoholic fermentation present bacterial loads between 102 and 104 cells/ml, after which in the exponential growing phase of the lactic bacteria registered at 5 days after sowing the selected malolactic bacteria, the bacterial density of wines to grow to 106 – 107 cells/ml, and at the end of malolactic fermentation, which matches the decline phase of lactic bacteria, the bacterial density of wines to get back to 105 cells/ml.

scholarly journals Ecological networks reveal contrasting patterns of bacterial and fungal communities in glacier-fed streams in Central Asia

2019 ◽  
Author(s):  
Ze Ren ◽  
Hongkai Gao
Keyword(s):  
Bacterial Community ◽  
Microbial Communities ◽  
Central Asia ◽  
Fungal Community ◽  
Bacterial Communities ◽  
Beta Diversity ◽  
Hydrological Modeling ◽  
Alpha Diversity ◽  
Environmental Variation ◽  
Fungal Communities

Bacterial and fungal communities in biofilms are important components in driving biogeochemical processes in stream ecosystems. Previous studies have well documented the patterns of bacterial alpha diversity in stream biofilms in glacier-fed streams, where, however, beta diversity of the microbial communities has received much less attention especially considering both bacterial and fungal communities. A focus on beta diversity can provide insights into the mechanisms driving community changes associated to large environmental fluctuations and disturbances, such as in glacier-fed streams. Moreover, modularity of co-occurrence networks can reveal more ecological and evolutionary properties of microbial communities beyond taxonomic groups. Here, integrating beta diversity and co-occurrence approach, we explored the network topology and modularity of the bacterial and fungal communities with consideration of environmental variation in glacier-fed streams in Central Asia. Combining results from hydrological modeling and normalized difference of vegetation index, this study highlighted that hydrological variables and vegetation status are major variables determining the environmental heterogeneity of glacier-fed streams. Bacterial communities formed a more complex and connected network, while the fungal communities formed a more clustered network. Moreover, the strong interrelations among the taxonomic dissimilarities of bacterial community and modules suggest they had common processes in driving diversity and taxonomic compositions across the heterogeneous environment. In contrast, fungal community and modules generally showed distinct driving processes to each other. Moreover, bacterial and fungal communities also had different driving processes. Furthermore, the variation of bacterial community and modules were strongly correlated with hydrological properties and vegetation status but not with nutrients, while fungal community and modules (except one module) were not associated with environmental variation. Our results suggest that bacterial and fungal communities had distinct mechanisms in structuring microbial networks, and environmental variation had strong influences on bacterial communities but not on fungal communities. The fungal communities have unique assembly mechanisms and physiological properties which might lead to their insensitive responses to environmental variations compared to bacterial communities. Overall, beyond alpha diversity in previous studies, these results add our knowledge that bacterial and fungal communities have contrasting assembly mechanisms and respond differently to environmental variation in glacier-fed streams.

scholarly journals Ecological networks reveal contrasting patterns of bacterial and fungal communities in glacier-fed streams in Central Asia

2019 ◽  
Author(s):  
Ze Ren ◽  
Hongkai Gao
Keyword(s):  
Bacterial Community ◽  
Microbial Communities ◽  
Central Asia ◽  
Fungal Community ◽  
Bacterial Communities ◽  
Beta Diversity ◽  
Hydrological Modeling ◽  
Alpha Diversity ◽  
Environmental Variation ◽  
Fungal Communities

Bacterial and fungal communities in biofilms are important components in driving biogeochemical processes in stream ecosystems. Previous studies have well documented the patterns of bacterial alpha diversity in stream biofilms in glacier-fed streams, where, however, beta diversity of the microbial communities has received much less attention especially considering both bacterial and fungal communities. A focus on beta diversity can provide insights into the mechanisms driving community changes associated to large environmental fluctuations and disturbances, such as in glacier-fed streams. Moreover, modularity of co-occurrence networks can reveal more ecological and evolutionary properties of microbial communities beyond taxonomic groups. Here, integrating beta diversity and co-occurrence approach, we explored the network topology and modularity of the bacterial and fungal communities with consideration of environmental variation in glacier-fed streams in Central Asia. Combining results from hydrological modeling and normalized difference of vegetation index, this study highlighted that hydrological variables and vegetation status are major variables determining the environmental heterogeneity of glacier-fed streams. Bacterial communities formed a more complex and connected network, while the fungal communities formed a more clustered network. Moreover, the strong interrelations among the taxonomic dissimilarities of bacterial community and modules suggest they had common processes in driving diversity and taxonomic compositions across the heterogeneous environment. In contrast, fungal community and modules generally showed distinct driving processes to each other. Moreover, bacterial and fungal communities also had different driving processes. Furthermore, the variation of bacterial community and modules were strongly correlated with hydrological properties and vegetation status but not with nutrients, while fungal community and modules (except one module) were not associated with environmental variation. Our results suggest that bacterial and fungal communities had distinct mechanisms in structuring microbial networks, and environmental variation had strong influences on bacterial communities but not on fungal communities. The fungal communities have unique assembly mechanisms and physiological properties which might lead to their insensitive responses to environmental variations compared to bacterial communities. Overall, beyond alpha diversity in previous studies, these results add our knowledge that bacterial and fungal communities have contrasting assembly mechanisms and respond differently to environmental variation in glacier-fed streams.

scholarly journals THE INFLUENCE OF YEAST RACES ON THE AROMA-FORMING SUBSTANCES OF TABLE WINES

2021 ◽  
Vol 447 (3) ◽  
pp. 13-18
Author(s):  
Z.А. Anarbekova ◽  
G.I. Baigazieva
Keyword(s):  
Direct Contact ◽  
Fermentation Process ◽  
Alcoholic Fermentation ◽  
Grape Juice ◽  
Yeast Cells ◽  
Higher Alcohols ◽  
Long Time ◽  
Speed Up ◽  
Biotechnological Processes

Wine is a product of biochemical transformations, compounds present in grape juice, by controlled alcoholic fermentation, that is, effervescence. Grape and yeast enzymes play a key role in the processing of grapes and the preparation of wine, influencing all biotechnological processes of winemaking. Adding liquid or dry active yeast to the wort allows better control of the fermentation process. Under the influence of these yeasts, sugar is converted mainly into alcohol or carbon dioxide, but the yeast itself during fermentation produces many molecules (higher alcohols, esters) that affect the aroma and taste of wine. These transformations take about two weeks and lead to a significant increase in temperature, which must be regulated, not allowing it to rise above 18-20°C: otherwise, some of the aromatic substances may evaporate and the fermentation process itself will stop. The amount of yeast that determines the correct and complete fermentation depends both on the quality of the wort itself, and on the more or less prolonged access of air, the ambient temperature. The air, or rather the oxygen of the air, has a beneficial effect on fermentation as long as there are still many nutrients (sugars) in the wort; as the latter are consumed, extremely small yeast cells are formed, which persist for a long time in the form of turbidity. The rapid course of fermentation can be greatly facilitated by the periodic stirring of yeast, which, settling to the bottom, lose direct contact with nutrients — the lower layers almost do not function. You can mix the wort mechanically or by adding healthy whole grapes to it; in this case, the wort is constantly and automatically mixed: the berries, rising up in the fermenting liquid, carry the yeast with them. In order to speed up the fermentation, the wort is sometimes ventilated, that is, air is introduced into it, by mixing. This article shows the influence of the yeast race on the fermentation dynamics of white grape must, the composition of organic acids and aroma-forming components. The races that ensure the production of highquality wine materials are identified.

scholarly journals A Culture-independent Approach to Understanding the Role of Soil Fungal Communities in Bromus tectorum Stand Failure

2020 ◽  
Author(s):  
Nathan Ricks ◽  
Taryn Williamson ◽  
Susan Meyer ◽  
John Chaston ◽  
Craig Coleman
Keyword(s):  
Bromus Tectorum ◽  
Fungal Communities ◽  
Culture Independent
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