scholarly journals Looking at the Origin: Some Insights into the General and Fermentative Microbiota of Vineyard Soils

Fermentation ◽  
2019 ◽  
Vol 5 (3) ◽  
pp. 78 ◽  
Author(s):  
Alejandro Alonso ◽  
Miguel de Celis ◽  
Javier Ruiz ◽  
Javier Vicente ◽  
Eva Navascués ◽  
...  

In winemaking processes, there is a current tendency to develop spontaneous fermentations taking advantage of the metabolic diversity of derived from the great microbial diversity present in grape musts. This enological practice enhances wine complexity, but undesirable consequences or deviations could appear on wine quality. Soil is a reservoir of important microorganisms for different beneficial processes, especially for plant nutrition, but it is also the origin of many of the phytopathogenic microorganisms that affect vines. In this study, a meta-taxonomic analysis of the microbial communities inhabiting vineyard soils was realized. A significant impact of the soil type and climate aspects (seasonal patterns) was observed in terms of alpha and beta bacterial diversity, but fungal populations appeared as more stable communities in vineyard soils, especially in terms of alpha diversity. Focusing on the presence and abundance of wine-related microorganisms present in the studied soils, some seasonal and soil-dependent patterns were observed. The Lactobacillaceae family, containing species responsible for the malolactic fermentation, was only present in non-calcareous soils samples and during the summer season. The study of wine-related fungi indicated that the Debaryomycetaceae family dominates the winter yeast population, whereas the Saccharomycetaceae family, containing the most important fermentative yeast species for winemaking, was detected as dominant in summer.

2021 ◽  
Vol 9 (6) ◽  
pp. 1273
Author(s):  
Nazareth Torres ◽  
Runze Yu ◽  
S. Kaan Kurtural

Vineyard-living microbiota affect grapevine health and adaptation to changing environments and determine the biological quality of soils that strongly influence wine quality. However, their abundance and interactions may be affected by vineyard management. The present study was conducted to assess whether the vineyard soil microbiome was altered by the use of biostimulants (arbuscular mycorrhizal fungi (AMF) inoculation vs. non-inoculated) and/or irrigation management (fully irrigated vs. half irrigated). Bacterial and fungal communities in vineyard soils were shaped by both time course and soil management (i.e., the use of biostimulants and irrigation). Regarding alpha diversity, fungal communities were more responsive to treatments, whereas changes in beta diversity were mainly recorded in the bacterial communities. Edaphic factors rarely influence bacterial and fungal communities. Microbial network analyses suggested that the bacterial associations were weaker than the fungal ones under half irrigation and that the inoculation with AMF led to the increase in positive associations between vineyard-soil-living microbes. Altogether, the results highlight the need for more studies on the effect of management practices, especially the addition of AMF on cropping systems, to fully understand the factors that drive their variability, strengthen beneficial microbial networks, and achieve better soil quality, which will improve crop performance.


2021 ◽  
Vol 22 (3) ◽  
pp. 1196
Author(s):  
Javier Vicente ◽  
Fernando Calderón ◽  
Antonio Santos ◽  
Domingo Marquina ◽  
Santiago Benito

The surfaces of grapes are covered by different yeast species that are important in the first stages of the fermentation process. In recent years, non-Saccharomyces yeasts such as Torulaspora delbrueckii, Lachancea thermotolerans, Metschnikowia pulcherrima, and Pichia kluyveri have become popular with regard to winemaking and improved wine quality. For that reason, several manufacturers started to offer commercially available strains of these non-Saccharomyces species. P. kluyveri stands out, mainly due to its contribution to wine aroma, glycerol, ethanol yield, and killer factor. The metabolism of the yeast allows it to increase volatile molecules such as esters and varietal thiols (aroma-active compounds), which increase the quality of specific varietal wines or neutral ones. It is considered a low- or non-fermentative yeast, so subsequent inoculation of a more fermentative yeast such as Saccharomyces cerevisiae is indispensable to achieve a proper fermented alcohol. The impact of P. kluyveri is not limited to the grape wine industry; it has also been successfully employed in beer, cider, durian, and tequila fermentation, among others, acting as a promising tool in those fermentation processes. Although no Pichia species other than P. kluyveri is available in the regular market, several recent scientific studies show interesting improvements in some wine quality parameters such as aroma, polysaccharides, acid management, and color stability. This could motivate yeast manufacturers to develop products based on those species in the near future.


Biochar ◽  
2021 ◽  
Author(s):  
Manuel García-Jaramillo ◽  
Kylie M. Meyer ◽  
Claire L. Phillips ◽  
Verónica Acosta-Martínez ◽  
James Osborne ◽  
...  

Fermentation ◽  
2020 ◽  
Vol 6 (3) ◽  
pp. 89
Author(s):  
David Castrillo ◽  
Noemi Neira ◽  
Pilar Blanco

Yeast play an essential role in wine quality. The dynamics of yeast strains during fermentation determine the final chemical and sensory characteristics of wines. This study aims to evaluate the Saccharomyces cerevisiae strains diversity in organic wineries from Galicia (NW Spain). Samples from spontaneous fermentations were taken in five wineries over three consecutive years (2013 to 2015). The samples were transported to the laboratory and processed following standard methodology for yeast isolation. S. cerevisiae strains were differentiated by mDNA-RFLPs. A total of 66 different strains were identified. Some of them presented a wide distribution and appeared in several wineries. However, other strains were typical from a specific winery. Similarity analysis using two different statistical tests showed significant differences in strain diversity among wineries. The results also revealed high biodiversity indexes; however, only some strains showed an important incidence in their distribution and frequency. Our findings confirmed that spontaneous fermentation favored the existence of a high S. cerevisiae strain diversity in organic wineries from Galicia. The presence of different yeasts during fermentation, specially winery-specific strains, contribute to increased wine complexity and differentiation.


2019 ◽  
Vol 3 (Supplement_1) ◽  
Author(s):  
Marie van der Merwe ◽  
Sunita Sharma ◽  
Jade Caldwell ◽  
Nicholas Smith ◽  
Richard Bloomer ◽  
...  

Abstract Objectives The gut microbiome participates in host metabolic regulation. While the vast majority of microbiome research has focused on bacterial populations, other microorganisms also colonize the mammalian intestine and likely play functionally important roles in host metabolism. The objective of current study was to characterize the role of dietary composition and timing strategies upon gut fungal populations. Methods C57BL/6 male mice were randomized to a Chow diet or a high-fat diet (HFD) for 6 weeks, followed by a switch from HFD to 1) Chow (sChow), 2) Purified High Fiber – Daniel Fast (DF), 3) HFD ad lib, 4) HFD time restricted (TRF), 5) HFD alternative day fasting (ADF), or 6) HFD 60% caloric restriction (CR) for an additional 8 weeks. Ileal, cecal and serial fecal samples were collected for next generation sequencing of ITS2 rRNA to examine the gut mycobiome. Results We observed dramatic reductions in alpha diversity in fecal fungal populations when animals consumed the HFD compared with Chow. HFD resulted in dramatic reduction in the relative abundance of the fungal order Saccharomyces, with a concomitant increases in the genus Candida and Hanseniaspora. In response to dietary switch from HFD to Chow, fungal taxonomic composition, alpha, and beta diversity transitioned to a population clustering more similarity with Chow by weeks 4 and 8 of intervention. After 8 weeks on the respective dietary interventions, alpha diversity of the ileal, cecal and fecal fungal population in mice consuming DF or various HFD fasting protocols remained similar to the HFD controls. Saccharomycetales remained the dominant genus present in HFD and DF groups. However, amongst these groups, the DF group (fecal sample) showed the greatest increase in Saccharomyces, but time-restricted feeding protocols also showed increased levels of Saccharomyces. Conclusions While fasting protocols on HFD are associated with improved metabolic outcomes, these data demonstrate that – similar to microbial populations within the microbiome – diet remains the largest driver of microorganism community composition. To our knowledge, this is the first investigation into the role of dietary timing strategies upon the gut fungal communities ever reported. Funding Sources University of Memphis. Children's Foundation Research Institute, Memphis.


Author(s):  
Robert E. White

The first edition of Understanding Vineyard Soils has been praised for its comprehensive coverage of soil topics relevant to viticulture. However, the industry is dynamic--new developments are occurring, especially with respect to measuring soil variability, managing soil water, possible effects of climate change, rootstock breeding and selection, monitoring sustainability, and improving grape quality and the "typicity" of wines. All this is embodied in an increased focus on the terroir or "sense of place" of vineyard sites, with greater emphasis being placed on wine quality relative to quantity in an increasingly competitive world market. The promotion of organic and biodynamic practices has raised a general awareness of "soil health", which is often associated with a soil's biology, but which to be properly assessed must be focused on a soil's physical, chemical, and biological properties. This edition of White's influential book presents the latest updates on these and other developments in soil management in vineyards. With a minimum of scientific jargon, Understanding Vineyard Soils explains the interaction between soils on a variety of parent materials around the world and grapevine growth and wine typicity. The essential chemical and physical processes involving nutrients, water, oxygen and carbon dioxide, moderated by the activities of soil organisms, are discussed. Methods are proposed for alleviating adverse conditions such as soil acidity, sodicity, compaction, poor drainage, and salinity. The pros and cons of organic viticulture are debated, as are the possible effects of climate change. The author explains how sustainable wine production requires winegrowers to take care of the soil and minimize their impact on the environment. This book is a practical guide for winegrowers and the lay reader who is seeking general information about soils, but who may also wish to pursue in more depth the influence of different soil types on vine performance and wine character.


2021 ◽  
Author(s):  
Nazareth Torres ◽  
Runze Yu ◽  
Kurtural Kurtural

Abstract Background: Vineyard-living microbiota play a relevant role in supporting grapevine health and adaptation to changing environments and determining the biological quality of soils that strongly influence the wine quality and characteristics. However, management practices may shape the abundance and interactions of bacteria and fungi in vineyard soils. We conducted this experiment to assess whether the vineyard soil microbiome was altered by different management practices with the use of biostimulants (arbuscular mycorrhizal fungi (AMF) inoculation vs. non-inoculated) and/or irrigation management (full irrigated vs. half irrigated). Results: Bacterial and fungal communities in vineyard soils were shaped by both time course and soil management (i.e. use of biostimulants or irrigation). Regarding alpha diversity, fungal communities were more responsive to treatments whereas changes on beta diversity were mainly recorded in the bacterial communities. Edaphic factors rarely influenced bacterial and fungal communities. Microbial network analyses suggested that the bacterial associations were weaker than the fungal ones under half irrigation and that the inoculation with AMF led to the increase of positive associations between vineyard soil-living microbes. Conclusion: Our results indicated different sensibilities within microbial communities living in vineyards, as well as, how they changed during the season, and in response to management practices. Moreover, results highlighted the need of more studies leading with the effect of management practices, especially the addition of AMF, to cropping systems to fully understand the factors that drive their variability, strengthen beneficial microbial networks and achieved a better soil quality that improves crop performance.


Author(s):  
R.A. Ploc

The optic axis of an electron microscope objective lens is usually assumed to be straight and co-linear with the mechanical center. No reason exists to assume such perfection and, indeed, simple reasoning suggests that it is a complicated curve. A current centered objective lens with a non-linear optic axis when used in conjunction with other lenses, leads to serious image errors if the nature of the specimen is such as to produce intense inelastic scattering.


Author(s):  
L. E. Murr ◽  
G. Wong

Palladium single-crystal films have been prepared by Matthews in ultra-high vacuum by evaporation onto (001) NaCl substrates cleaved in-situ, and maintained at ∼ 350° C. Murr has also produced large-grained and single-crystal Pd films by high-rate evaporation onto (001) NaCl air-cleaved substrates at 350°C. In the present work, very large (∼ 3cm2), continuous single-crystal films of Pd have been prepared by flash evaporation onto air-cleaved (001) NaCl substrates at temperatures at or below 250°C. Evaporation rates estimated to be ≧ 2000 Å/sec, were obtained by effectively short-circuiting 1 mil tungsten evaporation boats in a self-regulating system which maintained an optimum load current of approximately 90 amperes; corresponding to a current density through the boat of ∼ 4 × 104 amperes/cm2.


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