scholarly journals Terpenoids in Grapes and Wines: Origin and Micrometabolism during the Vinification Process

2008 ◽  
Vol 3 (4) ◽  
pp. 1934578X0800300 ◽  
Author(s):  
Francisco M. Carrau ◽  
Eduardo Boido ◽  
Eduardo Dellacassa
Keyword(s):  
De Novo ◽  
Wine Yeast ◽  
Wine Quality ◽  
Bacterial Fermentation ◽  
Yeast Strains ◽  
Wine Composition ◽  
Metabolic Footprinting ◽  
Grape Varieties ◽  
Near Future ◽  
Further Development

Terpenoids, which are typical components of the essential oils of flowers and fruits, are also present as free and glycosylated conjugates amongst the secondary metabolites of wine grape varieties of Vitis vinifera. Hence, when these compounds are present in wine, they are considered to originate from the grapes and not from fermentation. However, the biosynthesis of monoterpenes by Saccharomyces cerevisiae in the absence of grape derived precursors was shown recently to be of de novo origin in wine yeast strains. The contribution of yeast and bacterial fermentation metabolites to the aromatic profile of wine is well documented. However, the biotechnological application of this knowledge is still rather limited and often contradictory. Redox conditions, size of inoculums, temperatures of fermentation, osmotic pressure and the medium nutritional content can profoundly affect the profile of yeast and bacterial metabolites produced or their biotransformation capacity in wine. Results obtained in the last decades in relation to microbial micrometabolism of aroma compounds measured with more sophisticated GC-MS methods are discussed in relation to the known terpenoid biosynthetic pathways and wine composition. Further development of metabolic footprinting techniques for the discrimination of wine quality must be one of the main challenges for wine biotechnologists in the near future.

scholarly journals The genetic improvement of grapevine cultivars and wine yeast strains: Novel approaches to the ancient art of winemaking

2003 ◽  
Vol 22 (1) ◽  
pp. 31-43
Author(s):  
I. S. Pretorius
Keyword(s):  
Wine Yeast ◽  
Wine Industry ◽  
Market Demand ◽  
Wine Production ◽  
Yeast Strains ◽  
Quantum Leap ◽  
Grape Quality ◽  
The Cost ◽  
Grape Varieties ◽  
Grape Cultivars

The widening gap between wine production and wine consumption, the shift of consumer preferences away from basic commodity wine to top quality wine, and the gruelling competition brought about by economic globalisation call for a total revolution in  the magical world of wine. In the process of transforming the wine industry from a production-driven industry to a market-orientated enterprise, there is an increasing dependence on, amongst others, biotechnological innovation to launch the wine industry with a quantum leap across the formidable market challenges of the 21st century. Market-orientated designer grape cultivars and wine yeast strains are currently being genetically programmed with surgical precision for the cost-competitive production of high quality grapes and wine with relatively minimal resource inputs and a low environmental impact. With regard to Grapevine Biotechnology, this entails the establishment of stress tolerant and disease resistant varieties of Vitis vinifera with increased productivity, efficiency, sustainability and environmental friendliness, especially regarding improved pest and disease control, water use efficiency and grape quality. With regard to Wine Yeast Biotechnology, the emphasis is on the development of Saccharomyces cerevisiae strains with improved fermentation, processing and biopreservation abilities, and capacities for an increase in the wholesomeness and sensory quality of wine. The successful commercialisation of transgenic grape cultivars and wine yeasts depends on a number of scientific, technical, safety, ethical, legal, economic and marketing factors, and it therefore will be unwise to entertain high expectations in the short term. However, in the light of the phenomenal potential advantages of tailor-made grape varieties and yeast strains, it would be equally self-destructive in the long term if this strategically important “life insurance policy” is not taken out by the wine industry. This overview highlights the most important examples of the way in which V. vinifera grape varieties and S. cerevisiae wine yeast strains are currently being designed with surgical precision on the basis of market demand for the cost-effective, sustainable and environmentally friendly production of healthy, top quality grapes and wine.

scholarly journals The Influence of Non-Saccharomyces Species on Wine Fermentation Quality Parameters

Fermentation ◽  
2019 ◽  
Vol 5 (3) ◽  
pp. 54 ◽  
Author(s):  
Benito ◽  
Calderón ◽  
Benito
Keyword(s):  
Quality Parameters ◽  
Quality Improvements ◽  
Wine Quality ◽  
Yeast Strains ◽  
Fermentation Quality ◽  
Pichia Kluyveri ◽  
Near Future ◽  
Interesting Species ◽  
Spoilage Microorganisms

In the past, some microbiological studies have considered most non-Saccharomyces species to be undesirable spoilage microorganisms. For several decades, that belief made the Saccharomyces genus the only option considered by winemakers for achieving the best possible wine quality. Nevertheless, in recent decades, some strains of non-Saccharomyces species have been proven to improve the quality of wine. Non-Saccharomyces species can positively influence quality parameters such as aroma, acidity, color, and food safety. These quality improvements allow winemakers to produce innovative and differentiated wines. For that reason, the yeast strains Torulaspora delbrueckii, Lachancea thermotolerans, Metschnikowia pulcherrima, Schizosaccharomyces pombe, and Pichia kluyveri are now available on the market. Other interesting species, such as Starmerella bacillaris, Meyerozyma guilliermondii, Hanseniospora spp., and others, will probably be available in the near future.

scholarly journals An Overview of CRISPR-Based Technologies in Wine Yeasts to Improve Wine Flavor and Safety

Fermentation ◽  
2021 ◽  
Vol 7 (1) ◽  
pp. 5
Author(s):  
Alice Vilela
Keyword(s):  
Genetic Engineering ◽  
Wine Yeast ◽  
Wine Yeasts ◽  
Wine Quality ◽  
Yeast Strains ◽  
Off Flavors ◽  
Natural Isolates ◽  
The Stability ◽  
Wine Flavor ◽  
New Yeast

Modern industrial winemaking is based on the use of specific starters of wine strains. Commercial wine strains present several advantages over natural isolates, and it is their use that guarantees the stability and reproducibility of industrial winemaking technologies. For the highly competitive wine market with new demands for improved wine quality and wine safety, it has become increasingly critical to develop new yeast strains. In the last decades, new possibilities arose for creating upgraded wine yeasts in the laboratory, resulting in the development of strains with better fermentation abilities, able to improve the sensory quality of wines and produce wines targeted to specific consumers, considering their health and nutrition requirements. However, only two genetically modified (GM) wine yeast strains are officially registered and approved for commercial use. Compared with traditional genetic engineering methods, CRISPR/Cas9 is described as efficient, versatile, cheap, easy-to-use, and able to target multiple sites. This genetic engineering technique has been applied to Saccharomyces cerevisiae since 2013. In this review, we aimed to overview the use of CRISPR/Cas9 editing technique in wine yeasts to combine develop phenotypes able to increase flavor compounds in wine without the development of off-flavors and aiding in the creation of “safer wines.”

scholarly journals Comparative metabolic footprinting of a large number of commercial wine yeast strains in Chardonnay fermentations

2013 ◽  
Vol 13 (4) ◽  
pp. 394-410 ◽  
Author(s):  
Chandra L. Richter ◽  
Barbara Dunn ◽  
Gavin Sherlock ◽  
Tom Pugh
Keyword(s):  
Wine Yeast ◽  
Yeast Strains ◽  
Metabolic Footprinting

scholarly journals The Importance of Yeasts on Fermentation Quality and Human Health-Promoting Compounds

Fermentation ◽  
2019 ◽  
Vol 5 (2) ◽  
pp. 46 ◽  
Author(s):  
Alice Vilela
Keyword(s):  
Human Health ◽  
Wine Fermentation ◽  
Wine Quality ◽  
Fermented Beverages ◽  
Symbiotic Relationships ◽  
Yeast Strains ◽  
Wine Composition ◽  
Kombucha Tea ◽  
Health Promoting ◽  
Fermentation Quality

Non-Saccharomyces are important during wine fermentation once they influence wine composition. In the early stages of wine fermentation, and together with indigenous or commercial strains of Saccharomyces cerevisiae, non-Saccharomyces are able to transform grape-must sugars into ethanol, CO2, and other important secondary metabolites. A better understanding of yeast biochemistry will allow the selection of yeast strains that have defined specific influences on fermentation efficiency, wine quality, and the production of human health-promoting compounds. Yeast metabolism produces compounds derived from tryptophan, melatonin, and serotonin, which are found in fermented beverages, such as wine and beer. Melatonin is a neurohormone secreted from the pineal gland and has a wide-ranging regulatory and neuroprotective role, while serotonin, as well as being a precursor of melatonin synthesis, is also a neurotransmitter. This review summarizes the importance of some conventional and nonconventional yeast strains’ alcoholic fermentations, especially in the production of metabolites that promote human health and thus, attract consumers attention towards fermented beverages. A brief reference is also made on fermented beverages containing probiotics, namely kombucha, also known as kombucha tea, and its interesting microorganism’s symbiotic relationships named SCOBY.

scholarly journals Oenological Potential of Autochthonous Saccharomyces cerevisiae Yeast Strains from the Greek Varieties of Agiorgitiko and Moschofilero

Beverages ◽  
2021 ◽  
Vol 7 (2) ◽  
pp. 27
Author(s):  
Dimitrios Kontogiannatos ◽  
Vicky Troianou ◽  
Maria Dimopoulou ◽  
Polydefkis Hatzopoulos ◽  
Yorgos Kotseridis
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Alcoholic Fermentation ◽  
Ethanol Tolerance ◽  
Random Amplified Polymorphic Dna ◽  
Yeast Strains ◽  
Rapd Pcr ◽  
Autochthonous Yeast ◽  
Polymerase Chain ◽  
Grape Varieties ◽  
H2s Production

Nemea and Mantinia are famous wine regions in Greece known for two indigenous grape varieties, Agiorgitiko and Moschofilero, which produce high quality PDO wines. In the present study, indigenous Saccharomyces cerevisiae yeast strains were isolated and identified from spontaneous alcoholic fermentation of Agiorgitiko and Moschofilero musts in order to evaluate their oenological potential. Random amplified polymorphic DNA-polymerase chain reaction (RAPD-PCR) recovered the presence of five distinct profiles from a total of 430 yeast isolates. The five obtained strains were evaluated at microvinifications trials and tested for basic oenological and biochemical parameters including sulphur dioxide and ethanol tolerance as well as H2S production in sterile grape must. The selected autochthonous yeast strains named, Soi2 (Agiorgitiko wine) and L2M (Moschofilero wine), were evaluated also in industrial (4000L) fermentations to assess their sensorial and oenological characteristics. The volatile compounds of the produced wines were determined by GC-FID. Our results demonstrated the feasibility of using Soi2 and L2M strains in industrial fermentations for Agiorgitiko and Moschofilero grape musts, respectively.

scholarly journals The Fitness Advantage of Commercial Wine Yeasts in Relation to the Nitrogen Concentration, Temperature, and Ethanol Content under Microvinification Conditions

2013 ◽  
Vol 80 (2) ◽  
pp. 704-713 ◽  
Author(s):  
Estéfani García-Ríos ◽  
Alicia Gutiérrez ◽  
Zoel Salvadó ◽  
Francisco Noé Arroyo-López ◽  
José Manuel Guillamon
Keyword(s):  
Abiotic Factors ◽  
Nitrogen Concentration ◽  
Wine Yeast ◽  
Wine Industry ◽  
Wine Yeasts ◽  
Simple Method ◽  
Fitness Advantage ◽  
Yeast Strains ◽  
Industrial Strains ◽  
Nitrogen Concentrations

ABSTRACTThe effect of the main environmental factors governing wine fermentation on the fitness of industrial yeast strains has barely received attention. In this study, we used the concept of fitness advantage to measure how increasing nitrogen concentrations (0 to 200 mg N/liter), ethanol (0 to 20%), and temperature (4 to 45°C) affects competition among four commercial wine yeast strains (PDM, ARM, RVA, and TTA). We used a mathematical approach to model the hypothetical time needed for the control strain (PDM) to out-compete the other three strains in a theoretical mixed population. The theoretical values obtained were subsequently verified by competitive mixed fermentations in both synthetic and natural musts, which showed a good fit between the theoretical and experimental data. Specifically, the data show that the increase in nitrogen concentration and temperature values improved the fitness advantage of the PDM strain, whereas the presence of ethanol significantly reduced its competitiveness. However, the RVA strain proved to be the most competitive yeast for the three enological parameters assayed. The study of the fitness of these industrial strains is of paramount interest for the wine industry, which uses them as starters of their fermentations. Here, we propose a very simple method to model the fitness advantage, which allows the prediction of the competitiveness of one strain with respect to different abiotic factors.

Improvement of the remuneration system in modern conditions

2020 ◽  
pp. 6-12
Author(s):  
S. V. Savina
Keyword(s):  
Economic Growth ◽  
Productivity Growth ◽  
Positive Impact ◽  
Domestic Market ◽  
Effective Demand ◽  
Difficult Situation ◽  
Remuneration System ◽  
Near Future ◽  
Further Development

Today, a difficult situation has developed in the field of wages and incomes of the population, associated with the need to increase the level of wages and real incomes of the population, since low effective demand in the domestic market can become the main constraint on economic growth in the near future. The main goal of wage reform in modern conditions is to restore the role of wages as the main incentive for productivity growth and labor efficiency, which will have a positive impact on the functioning of production and will give an impetus to its further development.

scholarly journals Elements of a clinical trial protocol for medical devices

2017 ◽  
Vol 7 (6) ◽  
pp. 65
Author(s):  
Raymond P. Briggs ◽  
Lois Ramer
Keyword(s):  
Clinical Trial ◽  
Medical Device ◽  
De Novo ◽  
Evidence Based ◽  
Trial Protocol ◽  
Risk Class ◽  
Clinical Trial Protocol ◽  
Fda Approval ◽  
Near Future

Based on a Class 2 limited risk hospital based clinical trial, and a subsequent project retrospective, Briggs and Ramer propose an expanded clinical trial protocol.  Such an expanded protocol would be especially helpful for evaluating De Novo devices:  new inventions which require new processes for full hospital integration.  Since these new processes would often require training of nurses and supporting professionals, Briggs and Ramer suggest that nurse investigators could be very effective in carrying out such expanded protocol studies.  We briefly describe the FDA approval process, the role of the nurse in evidence based medical device evaluation, the Ramer, et al. clinical trial, the proposed expanded clinical trial protocol, and candidate categories of devices that might employ the limited risk Class 2 Medical Device clinical trial protocol.  The investigators look forward to carrying out such a medical device clinical trial in the near future.

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