scholarly journals Saccharomycodes ludwigii, Control and Potential Uses in Winemaking Processes

Fermentation ◽  
2018 ◽  
Vol 4 (3) ◽  
pp. 71 ◽  
Author(s):  
Ricardo Vejarano
Keyword(s):  
Electric Fields ◽  
Fermentation Process ◽  
Red Wines ◽  
Spoilage Yeast ◽  
Inhibitory Compounds ◽  
Potential Applications ◽  
Saccharomycodes Ludwigii ◽  
High Concentrations ◽  
Ageing On Lees ◽  
Saccharomyces Yeasts

Non-Saccharomyces yeasts are becoming important because most of them are considered as spoilage species in winemaking processes, among them the species Saccharomycodes ludwigii. This species is frequently isolated at the end of the fermentation process and/or during storage of the wine, i.e., it can to grow in the presence of high levels of ethanol. Besides, this species is adaptable to unfavorable conditions such as high concentrations of SO2 and is characterized by its capacity to produce high amounts of undesirable metabolites as acetoin, ethyl acetate or acetic acid. To the present, physical (gamma irradiation and continuous pulsed electric fields), chemical (inhibitory compounds such as chitosan and dimethyl dicarbonate) and biological (antagonistic biocontrol by killer yeasts) treatments have been developed in order to control the growth of this spoilage yeast in wines and other fruit derivatives. Therefore, this review is focused on the most relevant studies conducted to control contamination by S. ludwigii. Moreover, potential applications of S. ludwigii in alternative winemaking techniques, for example for ageing-on-lees and stabilization of red wines, and improvement of aromatic profile are also examined.

scholarly journals Pulsed Electric Fields to Improve the Use of Non-Saccharomyces Starters in Red Wines

Foods ◽  
2021 ◽  
Vol 10 (7) ◽  
pp. 1472
Author(s):  
Cristian Vaquero ◽  
Iris Loira ◽  
Javier Raso ◽  
Ignacio Álvarez ◽  
Carlota Delso ◽  
...  
Keyword(s):  
Electric Fields ◽  
Pulsed Electric Fields ◽  
The Other ◽  
Red Wines ◽  
Torulaspora Delbrueckii ◽  
Wild Yeast ◽  
Wild Yeasts ◽  
Natural Foods ◽  
Saccharomyces Yeasts ◽  
Lachancea Thermotolerans

New nonthermal technologies, including pulsed electric fields (PEF), open a new way to generate more natural foods while respecting their organoleptic qualities. PEF can reduce wild yeasts to improve the implantation of other yeasts and generate more desired metabolites. Two PEF treatments were applied; one with an intensity of 5 kV/cm was applied continuously to the must for further colour extraction, and a second treatment only to the must (without skins) after a 24-hour maceration of 17.5 kV/cm intensity, reducing its wild yeast load by up to 2 log CFU/mL, thus comparing the implantation and fermentation of inoculated non-Saccharomyces yeasts. In general, those treated with PEF preserved more total esters and formed more anthocyanins, including vitisin A, due to better implantation of the inoculated yeasts. It should be noted that the yeast Lachancea thermotolerans that had received PEF treatment produced four-fold more lactic acid (3.62 ± 0.84 g/L) than the control of the same yeast, and Hanseniaspora vineae with PEF produced almost three-fold more 2-phenylethyl acetate than the rest. On the other hand, 3-ethoxy-1-propanol was not observed at the end of the fermentation with a Torulaspora delbrueckii (Td) control but in the Td PEF, it was observed (3.17 ± 0.58 mg/L).

THALIDOMIDE MAKES A COMEBACK

PEDIATRICS ◽  
1995 ◽  
Vol 96 (1) ◽  
pp. 89-89
Author(s):  
J. F. L.
Keyword(s):  
Weight Loss ◽  
Associate Professor ◽  
Necrosis Factor Alpha ◽  
Morning Sickness ◽  
Patients With Cancer ◽  
Aids Virus ◽  
Potential Applications ◽  
Factor Alpha ◽  
High Concentrations ◽  
Necrosis Factor

Thalidomide, the drug responsible for the deformities of thousands of babies born in the 1950s, appears to be making a comeback. Scientists have recently reported that the sedative, once widely prescribed in Europe for morning sickness but long since banned for such use, may inhibit the AIDS virus as well as alleviate certain symptoms associated with tuberculosis and cancer. The first American patent for thalidomide was issued in 1958, but last week Gilla Kaplan, an associate professor of immunology at Rockefeller University who pioneered the new thalidomide research, received a patent covering new potential applications for the drug. "Thalidomide is really the treatment of choice for leprosy," she said. "It alleviates the weight loss and fevers. I figured if I knew how thalidomide worked I would understand what is causing the symptoms." "... thalidomide slows the body's production of a substance known as tumor necrosis factor alpha, a protein that at normal levels actually helps combat infection and malignant cells. But high concentrations of the protein appear to result in fever, weight loss, and other symptoms in patients with cancer, tuberculosis, and AIDS.

Ethanol Production from Non-Detoxified Steam-Exploded Corn Stover Subsequent Enzymatic Hydrolysis by Two Toxin-Tolerant Yeast Strains

2011 ◽  
Vol 365 ◽  
pp. 145-149
Author(s):  
Xun Men ◽  
Xiu Shan Yang ◽  
Shen Tian
Keyword(s):  
Enzymatic Hydrolysis ◽  
Ethanol Production ◽  
Corn Stover ◽  
Fermentation Process ◽  
Ethanol Concentration ◽  
Enzymatic Hydrolysate ◽  
Yeast Strains ◽  
Inhibitory Compounds ◽  
Operation Cost ◽  
Detoxification Process

Fermentation process for ethanol production from steam-exploded corn stover using toxin-tolerant yeast strains was carried out in order to reduce the water consumption and operation cost. The substrate from steam-exploded did not undergo a detoxification process by wash, and was directly hydrolyzed by enzymes. Two toxin-tolerant stains, Y1 and Y5, were tested to ferment the enzymatic hydrolysate slurry directly to ethanol. In the enzymatic hydrolysate slurry containing inhibitory compounds, the strain Y1 and Y5 could convert the sugar to ethanol with ethanol concentration of 47.0 g/L and 47.2 g/L corresponding to 95.9% and 96.4% of the theoretical maximum, respectively.

Effect of Dielectric Imperfections on the Electroactive Deformations of Polar Dielectric Elastomers

2019 ◽  
Vol 86 (8) ◽  
Author(s):  
Yanhui Jiang ◽  
Yang Liu
Keyword(s):  
Dielectric Permittivity ◽  
Shear Modulus ◽  
Electric Fields ◽  
Nonlinear Deformation ◽  
Dielectric Elastomers ◽  
Inhomogeneous Deformation ◽  
Polar Dielectric ◽  
Polar Groups ◽  
Deformation Stability ◽  
Potential Applications

We find that the ratio of dielectric permittivity to shear modulus is linearly related to the number of polar groups per polymer chain in polar dielectric elastomers (PDEs). Our discovery is verified via computational modeling and validated by experimental evidences. Based on the finding, we introduce the new concept of dielectric imperfection (DI) and provide some physical insights into understanding it through demonstrating the large nonlinear deformation of PDEs with DIs under electric fields. The results show remarkable DI-induced inhomogeneous deformation and indicate that the size and dielectric permittivity of DIs have a significant impact on the deformation stability of PDEs under electric fields. With this concept, we propose some potential applications of PDEs with DIs.

scholarly journals Characterizing the Potential of the Non-Conventional Yeast Saccharomycodes ludwigii UTAD17 in Winemaking

2019 ◽  
Vol 7 (11) ◽  
pp. 478 ◽  
Author(s):  
Esteves ◽  
Barbosa ◽  
Vasconcelos ◽  
Tavares ◽  
Mendes-Faia ◽  
...  
Keyword(s):  
Starter Culture ◽  
Grape Juice ◽  
Wine Quality ◽  
Mixed Culture Fermentation ◽  
Saccharomycodes Ludwigii ◽  
Saccharomyces Yeast ◽  
Low Levels ◽  
Wine Region ◽  
Potential Use ◽  
Saccharomyces Yeasts

Non-Saccharomyces yeasts have received increased attention by researchers and winemakers, due to their particular contributions to the characteristics of wine. In this group, Saccharomycodes ludwigii is one of the less studied species. In the present study, a native S. ludwigii strain, UTAD17 isolated from the Douro wine region was characterized for relevant oenological traits. The genome of UTAD17 was recently sequenced. Its potential use in winemaking was further evaluated by conducting grape-juice fermentations, either in single or in mixed-cultures, with Saccharomyces cerevisiae, following two inoculation strategies (simultaneous and sequential). In a pure culture, S. ludwigii UTAD17 was able to ferment all sugars in a reasonable time without impairing the wine quality, producing low levels of acetic acid and ethyl acetate. The overall effects of S. ludwigii UTAD17 in a mixed-culture fermentation were highly dependent on the inoculation strategy which dictated the dominance of each yeast strain. Wines whose fermentation was governed by S. ludwigii UTAD17 presented low levels of secondary aroma compounds and were chemically distinct from those fermented by S. cerevisiae. Based on these results, a future use of this non-Saccharomyces yeast either in monoculture fermentations or as a co-starter culture with S. cerevisiae for the production of wines with greater expression of the grape varietal character and with flavor diversity could be foreseen.

scholarly journals Genome Sequence of the Wine Yeast Saccharomycodes ludwigii UTAD17

2018 ◽  
Vol 7 (18) ◽  
Author(s):  
Maria J. Tavares ◽  
Ulrich Güldener ◽  
Marcos Esteves ◽  
Arlete Mendes-Faia ◽  
Ana Mendes-Ferreira ◽  
...  
Keyword(s):  
Genome Sequence ◽  
Wine Yeast ◽  
Aroma Compounds ◽  
Content Type ◽  
Fermented Beverages ◽  
Spoilage Yeast ◽  
Wine Spoilage ◽  
Saccharomycodes Ludwigii ◽  
First Time

This work describes, for the first time, the genome sequence of a Saccharomycodes ludwigii strain. Although usually seen as a wine spoilage yeast, S. ludwigii has been of interest for the production of fermented beverages because it harbors several interesting properties, including the production of beneficial aroma compounds.

scholarly journals Pilot Scale Fermentations of Sangiovese: An Overview on the Impact of Saccharomyces and Non-Saccharomyces Wine Yeasts

Fermentation ◽  
2020 ◽  
Vol 6 (3) ◽  
pp. 63 ◽  
Author(s):  
Cristina Romani ◽  
Livio Lencioni ◽  
Alessandra Biondi Bartolini ◽  
Maurizio Ciani ◽  
Ilaria Mannazzu ◽  
...  
Keyword(s):  
Pilot Scale ◽  
Wine Industry ◽  
Red Wines ◽  
Microbiological Control ◽  
Sensory Analyses ◽  
Quantitative Descriptive ◽  
Red Grape ◽  
The Impact ◽  
Sampling Times ◽  
Saccharomyces Yeasts

The production of wines with peculiar analytical and sensorial profiles, together with the microbiological control of the winemaking process, has always been one of the main objectives of the wine industry. In this perspective, the use of oenological starters containing non-Saccharomyces yeasts can represent a valid tool for achieving these objectives. Here we present the results of seven pilot scale fermentations, each of which was inoculated with a different non-Saccharomyces yeast strain and after three days with a commercial Saccharomyces cerevisiae starter. The fermentations were carried out in double on 70 L of Sangiovese grape must, the most widely planted red grape variety in Italy and particularly in Tuscany, where it is utilized for the production of more than 80% of red wines. Fermentations were monitored by assessing both the development of the microbial population and the consumption of sugars at the different sampling times. The impact of the different starters was assessed after stabilization through the evaluation of the standard analytical composition of the resulting wines, also taking into account polysaccharides and volatile compounds. Moreover, quantitative descriptive sensory analyses were carried out. Compared to the control wines obtained by inoculating the S. cerevisiae starter strain, those inoculated with non-Saccharomyces/Saccharomyces mixed starters presented a significant differentiation in the chemical-analytical composition. Moreover, sensory analysis revealed differences among wines mainly for intensity of color, astringency, and dryness mouthfeel perception.

scholarly journals Water-structuring molecules and nanomaterials enhance radiofrequency heating in biologically relevant solutions

2016 ◽  
Vol 52 (85) ◽  
pp. 12630-12633 ◽  
Author(s):  
Nadia C. Lara ◽  
Asad A. Haider ◽  
Jason C. Ho ◽  
Lon J. Wilson ◽  
Andrew R. Barron ◽  
...  
Keyword(s):  
Aqueous Solution ◽  
Electric Fields ◽  
Biologically Relevant ◽  
Water Structuring ◽  
Radiofrequency Heating ◽  
Potential Applications ◽  
Cancer Hyperthermia

For potential applications in nano-mediated radiofrequency cancer hyperthermia, the nanomaterial under investigation must increase the heating of any aqueous solution in which it is suspended when exposed to radiofrequency electric fields.

scholarly journals New trends on yeast autolysis and wine ageing on lees: a bibliographic review

OENO One ◽  
2002 ◽  
Vol 36 (2) ◽  
pp. 49 ◽  
Author(s):  
Caroline Fornairon-Bonnefond ◽  
Carole Camarasa ◽  
Michel Moutounet ◽  
Jean-Michel Salmon
Keyword(s):  
Experimental Methods ◽  
Point Of View ◽  
Red Wines ◽  
Organic Residues ◽  
Yeast Autolysis ◽  
Definition Of ◽  
Effects Of Aging ◽  
Ageing On Lees ◽  
Experimental Stage ◽  
Wine Ageing

<p style="text-align: justify;">In enology, «grands crus» white wines are traditionally aged by the «sur lies» method, which consists of keeping the aging wine in contact with the lees (yeasts and organic residues). The lees can come either from the first or second fermentation and can be used for both white and red wines. This practice is still in the experimental stage. We reviewed scientific studies carried out on wine lees to determine the current situation in enology. We also provide some technological information relevant to such a practice.</p><p style="text-align: justify;">The first part of this paper provides a clear definition of wine lees from a legal and technological point of view. The second part describes the mechanisms of autolysis and focuses on each class of autolysis product. Many scientific studies have discussed the phenomenon of yeast autolysis during wine ageing. Most of these studies simply identified the yeast macromolecules released into the wine during autolysis. However, the experimental methods used vary and it is difficult to extrapolate most of results to the process of wine ageing on lees. Only a few studies have dealt with the physicochemical properties of lees during autolysis, especially concerning oxygen, polyphenols and other wine compounds. We then summarize the recent data obtained on these topics. Finally, we discuss the technical effects of aging wine on lees.</p>

scholarly journals Mechanoresponsive scatterers for high-contrast optical modulation

Nanophotonics ◽  
2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Donghwi Cho ◽  
Haomin Chen ◽  
Jonghwa Shin ◽  
Seokwoo Jeon
Keyword(s):  
Energy Consumption ◽  
Electric Fields ◽  
Structural Parameters ◽  
Future Research ◽  
Great Promise ◽  
Design Strategies ◽  
Smart Windows ◽  
Advantages And Disadvantages ◽  
Potential Applications ◽  
External Stimuli

Abstract Smart chromatic materials with optical transmittances that can be modified by light scattering upon external stimuli are attracting extensive interest because of their appealing applications in smart windows, privacy protection, electronic displays, etc. However, the development of these scatterers, which are mostly activated by electric fields, is hindered by their intrinsic energy consumption, slow responses, and poor stability. Recently, mechanoresponsive scatterers based on a strain-driven reconfiguration of the surface or internal structure have emerged, featuring fast responses and a simple composition/fabrication. Because there is no energy consumption to maintain the transparency/opacity, this novel scheme for scatterers holds great promise to break the existing bottleneck. This article presents recent advances in the development of mechanoresponsive scatterers and compares different structural design strategies. The scatterers are categorized into 2D, 3D, and other types according to the dimensions of their functioning structures. The fabrication methods, mechanisms, and relationships between the structural parameters and optical modulating performances are discussed for each category. Next, the potential applications of these scatterers are outlined. Finally, the advantages and disadvantages of the mainstream 2D and 3D categories are summarized, followed by a perspective on future research directions.

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