Effect of pH on successive foam and sonic droplet fractionation of a bromelain-invertase mixture

A droplet fractionation method was previously developed to concentrate a dilute nonfoaming protein solution. In that earlier study with invertase, it was demonstrated that droplets created by ultrasonic energy waves could be enriched up to 8 times that of the initial dilute invertase solution. In this study, a mixture of bromelain (a foaming protein) and invertase (a nonfoaming protein) is investigated as a preliminary step to determine if droplet fractionation can also be used to separate a non-foaming protein from foaming proteins. The foaming mixture containing bromelain is first removed by bubbling the binary mixture with air. After the foam is removed, the protein rich air-water interfacial layer is skimmed off (prior to droplet fractionation) so as not to interfere with the subsequent droplet production from the remaining bulk liquid, rich in non-foaming protein. Finally, sonic energy waves are then applied to this residual bulk liquid to recover droplets containing the non-foaming protein, presumed to be invertase. The primary control variable used in this droplet fractionation process is the pH, which ranged for separate experiments between 2 and 9. It was observed that the maximum overall protein partition coefficients of 5 and 4 were achieved at pH 2 and 4, respectively, for the initial foaming experiment followed by the post foaming droplet fractionation experiment.     

Divergence in wine characteristics produced by wild and domesticated strains of Saccharomyces cerevisiae

The budding yeast Saccharomyces cerevisiae is the primary species used by wine makers to convert sugar into alcohol during wine fermentation. Saccharomyces cerevisiae is found in vineyards, but is also found in association with oak trees and other natural sources. Although wild strains of S. cerevisiae as well as other Saccharomyces species are also capable of wine fermentation, a genetically distinct group of S. cerevisiae strains is primarily used to produce wine, consistent with the idea that wine making strains have been domesticated for wine production. In this study, we demonstrate that humans can distinguish between wines produced using wine strains and wild strains of S. cerevisiae as well as its sibling species, Saccharomyces paradoxus. Wine strains produced wine with fruity and floral characteristics, whereas wild strains produced wine with earthy and sulfurous characteristics. The differences that we observe between wine and wild strains provides further evidence that wine strains have evolved phenotypes that are distinct from their wild ancestors and relevant to their use in wine production.     

Characteristics of wine produced by mushroom fermentation

Saccharomyces cerevisiae is the main microorganism used in wine brewing, because this microbe has potent ability to produce alcohol dehydrogenase. We have recently discovered that some genera of mushroom produced alcohol dehydrogenase, and made wine by using a mushroom in place of S. cerevisiae. The highest alcohol concentration in this wine was achieved with Pleurotus ostreatus (2.6 M, 12.2%). In the case of Agaricus blazei, the same alcohol concentration (1.7 M, 8%) was produced under both aerobic and anaerobic conditions. This wine produced by A. blazei contained about 0.68% beta-D-glucan, which is known to have a preventive effects against cancer. The wine made by using Flammulina velutipes showed thrombosis-preventing activity, giving a prolonged thrombin clotting time 2.2-fold that of the control. Thus, the wine made by using mushroom seems to be a functional food which can be expected to have preventive effects against cancer and thrombosis.     

Characteristics of Wine Produced by Mushroom Fermentation

Saccharomyces cerevisiae is the main microorganism used in wine brewing, because this microbe has potent ability to produce alcohol dehydrogenase. We have recently discovered that some genera of mushroom produced alcohol dehydrogenase, and made wine by using a mushroom in place of S. cerevisiae. The highest alcohol concentration in this wine was achieved with Pleurotus ostreatus (2.6 M, 12.2%). In the case of Agaricus blazei, the same alcohol concentration (1.7 M, 8%) was produced under both aerobic and anaerobic conditions. This wine produced by A. blazei contained about 0.68% β-D-glucan, which is known to have a preventive effects against cancer. The wine made by using Flammulina velutipes showed thrombosis-preventing activity, giving a prolonged thrombin clotting time 2.2-fold that of the control. Thus, the wine made by using mushroom seems to be a functional food which can be expected to have preventive effects against cancer and thrombosis     

Molecular basis of fructose utilization by the wine yeast Saccharomyces cerevisiae: a mutated HXT3 allele enhances fructose fermentation

Fructose utilization by wine yeasts is critically important for the maintenance of a high fermentation rate at the end of alcoholic fermentation. A Saccharomyces cerevisiae wine yeast able to ferment grape must sugars to dryness was found to have a high fructose utilization capacity. We investigated the molecular basis of this enhanced fructose utilization capacity by studying the properties of several hexose transporter (HXT) genes. We found that this wine yeast harbored a mutated HXT3 allele. A functional analysis of this mutated allele was performed by examining expression in an hxt1-7Delta strain. Expression of the mutated allele alone was found to be sufficient for producing an increase in fructose utilization during fermentation similar to that observed in the commercial wine yeast. This work provides the first demonstration that the pattern of fructose utilization during wine fermentation can be altered by expression of a mutated hexose transporter in a wine yeast. We also found that the glycolytic flux could be increased by overexpression of the mutant transporter gene, with no effect on fructose utilization. Our data demonstrate that the Hxt3 hexose transporter plays a key role in determining the glucose/fructose utilization ratio during fermentation.     

The winemaker's bug: From ancient wisdom to opening new vistas with frontier yeast science

The past three decades have seen a global wine glut. So far, well-intended but wasteful and expensive market-intervention has failed to drag the wine industry out of a chronic annual oversupply of roughly 15%. Can yeast research succeed where these approaches have failed by providing a means of improving wine quality, thereby making wine more appealing to consumers? To molecular biologists Saccharomyces cerevisiae is as intriguing as it is tractable. A simple unicellular eukaryote, it is an ideal model organism, enabling scientists to shed new light on some of the biggest scientific challenges such as the biology of cancer and aging. It is amenable to almost any modification that modern biology can throw at a cell, making it an ideal host for genetic manipulation, whether by the application of traditional or modern genetic techniques. To the winemaker, this yeast is integral to crafting wonderful, complex wines from simple, sugar-rich grape juice. Thus any improvements that we can make to wine, yeast fermentation performance or the sensory properties it imparts to wine will benefit winemakers and consumers. With this in mind, the application of frontier technologies, particularly the burgeoning fields of systems and synthetic biology, have much to offer in their pursuit of "novel" yeast strains to produce high quality wine. This paper discusses the nexus between yeast research and winemaking. It also addresses how winemakers and scientists face up to the challenges of consumer perceptions and opinions regarding the intervention of science and technology; the greater this intervention, the stronger the criticism that wine is no longer "natural." How can wine researchers respond to the growing number of wine commentators and consumers who feel that scientific endeavors favor wine quantity over quality and "technical sophistication, fermentation reliability and product consistency" over "artisanal variation"? This paper seeks to present yeast research in a new light and a new context, and it raises important questions about the direction of yeast research, its contribution to science and the future of winemaking.     

OBSERVATIONS ON FOAMING AND ITS INHIBITION IN A BACTERIAL CULTURE

SUMMARY: Inhibition of foaming in a continuous culture of bacteria has been studied. At first, foaming was inhibited by the addition of antifoam to the culture only when a foam layer was present. When the antifoam was added in this way foaming often became intense and antifoam additions had to be more and more frequent. In a preferred method the antifoam was added at regular intervals which were sufficiently short to inhibit foaming completely throughout the intervening periods. This method required less antifoam than the other. The effects of foaming in cultures, its causes, and allied problems are discussed.     

Red wine polyphenolics suppress the secretion and the synthesis of Apo B48 from human intestinal CaCo-2 cells

Epidemiological studies suggest that the red wine consumption may reduce the risk factor of cardiovascular disease. However, the mechanisms of how the red wine phenolic components reduce the risk of cardiovascular disease is currently unknown. Our previous study demonstrated that red wine polyphenolics suppress the secretion of pro-atherogenic lipoproteins (very low density lipoproteins) from human hepatic HepG2 cells. Therefore, in this study we hypothesize that red wine polyphenolics will also attenuate the production and secretion of another pro-atherogenic lipoprotein (chylomicrons) from human intestinal CaCo-2 cells. Cultured CaCo-2 cells were incubated in the presence of dealcoholized red wine, alcoholized red wine and atorvastatin for 24 h. The apo B48 protein (marker of intestinal chylomicrons) was quantified on Western blotting and the enhanced chemiluminescence. Apo B48 levels in the cells and that secreted into the media were significantly reduced by 29% in the cells incubated with dealcoholized red wine compared with control cells. Also the similar effect was shown in the cells incubated with alcoholized red wine. The cells incubated with atorvastatin shown the significant reduction of apo B48 production compared to control cells. Collectively, this study suggests that red wine polyphenolics down regulate the production of chylomicron in intestinal CaCo-2 cells.     

Molecular Basis of Fructose Utilization by the Wine Yeast Saccharomyces cerevisiae: a Mutated HXT3 Allele Enhances Fructose Fermentation

Fructose utilization by wine yeasts is critically important for the maintenance of a high fermentation rate at the end of alcoholic fermentation. A Saccharomyces cerevisiae wine yeast able to ferment grape must sugars to dryness was found to have a high fructose utilization capacity. We investigated the molecular basis of this enhanced fructose utilization capacity by studying the properties of several hexose transporter (HXT) genes. We found that this wine yeast harbored a mutated HXT3 allele. A functional analysis of this mutated allele was performed by examining expression in an hxt1-7Δ strain. Expression of the mutated allele alone was found to be sufficient for producing an increase in fructose utilization during fermentation similar to that observed in the commercial wine yeast. This work provides the first demonstration that the pattern of fructose utilization during wine fermentation can be altered by expression of a mutated hexose transporter in a wine yeast. We also found that the glycolytic flux could be increased by overexpression of the mutant transporter gene, with no effect on fructose utilization. Our data demonstrate that the Hxt3 hexose transporter plays a key role in determining the glucose/fructose utilization ratio during fermentation.     

Modulation of cytochrome P450 activity in the kidney of rats following long-term red wine exposure

Cytochrome P450 (CYP)-dependent oxidation of lauric acid, p-nitrophenol and ethanol by microsomal fractions of kidney were studied in control rats and in animals given either ethanol, red wine, or alcohol-free red wine for 10 weeks. Ethanol increased the total CYP content and specifically CYP 2E1, as well as p-nitrophenol and ethanol oxidation. The effects of ethanol treatment on the content and activity of CYP 2E1 were attenuated when red wine was administered, while the alcohol-free red wine values were similar to those of the control group. Although lauric acid hydroxylation was decreased by red wine treatment, the content of CYP 4A1 was not influenced by drinking fluids. We conclude that red wine administration attenuates the ethanol-induced enhancement of microsomal activities dependent on CYP 2E1 of rat kidney. Our results suggest that the non-alcoholic constituents of red wine could account for this modulation.     

Moderate acute intake of de-alcoholized red wine, but not alcohol, is protective against radiation-induced DNA damage ex vivo -- results of a comparative in vivo intervention study in younger men

Moderate intake of wine is associated with reduced risk of cardiovascular disease and possibly cancer however it remains unclear whether the potential health benefits of wine intake are due to alcohol or the non-alcoholic fraction of wine. We therefore tested the hypothesis that the non-alcoholic fraction of wine protects against genome damage induced by oxidative stress in a crossover intervention study involving six young adult males aged 21-26 years. The participants adhered to a low plant phenolic compound diet for 48 h prior to consuming 300 mL of complete red wine, de-alcoholized red wine or ethanol on separate occasions 1 week apart. Blood samples were collected 0.5, 1.0 and 2.0 h after beverage consumption. Baseline and radiation-induced genome damage was measured using the cytokinesis-block micronucleus assay and total plasma catechin concentration was measured. Consumption of de-alcoholized red wine significantly decreased the gamma radiation-induced DNA damage at 1 and 2 h post-consumption by 20%. In contrast alcohol tended to increase radiation-induced genome damage and complete wine protected against radiation-induced genome damage relative to alcohol. The observed effects were only weakly correlated with the concentration of total plasma catechin (R=-0.23). These preliminary data suggest that only the non-alcoholic fraction of red wine protects DNA from oxidative damage but this effect cannot be explained solely by plasma catechin.     

Measuring the impact of temperature changes on the wine production in the Douro Region using the short time fourier transform

This paper investigates the cyclical behaviour of the wine production in Douro region during the period 1932–2008. In general, wine production is characterised by large fluctuations which are composed of short-term and/or long-term cycles. The aim of this paper is twofold: firstly, we decompose the wine production's variance in order to find the dominating production cycles, i.e we try to explain whether wine production follows more long-term or short-term cycles. In the next step, we try to explain those cycles using a dependent variable, namely the medium spring temperature (Tm_Sp) for the period 1967–2008. We estimated a Time-Varying Autoregressive Model, which could explain 75% of the production that is characterised by 4.8- and 2.5-year cycles. We use the Short Time Fourier Transform to decompose the link between wine production and temperature. When the temperature was incorporated, the R ² increased and the Akaike criterion value was lower. Hence, Tm_Sp causes a large amount of these cycles and the wine production variation reflects this relationship. In addition to an upward trend, there is a clearly identifiable cycle around the long-term trend in production. We also show how much of the production cycle and what cycle in particular is explained by the Tm_Sp. There is a stable but not constant link between production and the Tm_Sp. In particular, the temperature is responsible for 5.2- and 2.4-year cycles which has been happening since the 1980s. The Tm_Sp can also be used as an indicator for the 4.8- and 2.5-year cycles of production. The developed model suggests that stationarity is a questionable assumption, and this means that historical distributions of wine production are going to need dynamic updating.     

Carotenoid breakdown products the—norisoprenoids—in wine aroma

In recent years there has been much interest in the role that products of carotenoid breakdown—the norisoprenoids—may play in wine aroma. The basis for this interest is that norisoprenoids have very low olfactory perception thresholds and so have a high sensorial impact on wine aroma. The norisoprenoids can be formed by direct degradation of carotenoids such β-carotene and neoxanthin or they can be stored as glycoconjugates, which can then release their volatile aglycone during fermentation via enzymatic and acid hydrolysis processes. The norisoprenoids identified in wine with important sensory properties are: TCH (2,2,6-trimethylcyclohexanone), β-damascenone, β-ionone, vitispirane, actinidiol, TDN (1,1,6-trimethyl-1,2-dihydronaphthalene), riesling acetal and TPB (4-(2,3,6-trimethylphenyl)buta-1,3-diene). The grape carotenoid profile, fermentation process and wine storage conditions, are determinant factors for the aroma of wine. The mechanisms involved in overall aroma development from grapes through fermentation to wine are yet to be defined. Progress in this area will be reviewed.     

黄酒贮存酸败关键微生物的分离鉴定

【背景】贮存陈酿是黄酒生产的重要工艺环节,但由于黄酒中营养物质含量丰富,贮存陈酿过程中时常出现酸败变质的现象,尤其是在大罐的陈酿过程中酸败的发生对黄酒行业造成较大的经济损失。【目的】解析黄酒贮存陈酿过程中造成黄酒酸败的关键微生物,为黄酒贮存酸败微生物的控制提供依据。【方法】采用高通量测序技术分析不同来源酸败黄酒中的主要微生物种类;设计针对性培养基分离培养酸败黄酒中的难培养微生物;设计微生物特异性引物,对16S r RNA基因高度相似的酸败微生物进行区分鉴定;将分离的黄酒酸败微生物接入到未发生酸败的黄酒中验证其生酸能力。【结果】高通量测序技术分析结果显示,酸败黄酒中污染微生物主要为乳酸杆菌属(丰度95%)微生物,在种水平上分析比对结果显示两种难培养微生物[耐酸乳杆菌(Lactobacillus acetotolerans)和食果糖乳杆菌(Lactobacillus fructivorans)]的相对丰度达到了82%以上;采用改进的分离培养基分离出酸败黄酒中的难培养污染微生物36株;利用耐酸乳杆菌rec A基因和食果糖乳杆菌tuf基因的特异性引物准确鉴定出这些微生物菌株为28株耐酸乳杆菌和8株食果糖乳杆菌;将两种主要酸败微生物接入到未发生酸败的黄酒中,培养2周后能够显著提高黄酒酸度。【结论】基于高通量测序的未培养技术可作为食品中难培养污染微生物快速分析的有效方法。基于未培养技术和可培养技术相结合,首次解析并验证黄酒贮存过程中造成黄酒酸败的主要微生物为耐酸乳杆菌和食果糖乳杆菌。     

Alcohol, wine and platelet function

Epidemiological studies have demonstrated an inverse correlation between moderate wine and alcohol consumption and morbidity and mortality from coronary heart disease. The protective effect has been associated with an increase in the plasma level of HDL cholesterol, as it is well recognized that plasma HDL is inversely correlated with CHD. In addition, it has become evident that blood platelets contribute to the rate of development of atherosclerosis and CHD through several mechanisms. In recent studies it has been shown that the level of HDL cholesterol can explain only 50% of the protective effect of alcoholic beverages; the other 50% may be partly related to a decrease in platelet activity. This anti-platelet activity of wine is explained by ethanol but also by the polyphenolic components with which red wines are richly endowed. Several studies carried out on humans and animals have shown that wine phenolics could exert their effects by reducing prostanoid synthesis from arachidonate. In addition, it has been suggested that wine phenolics could reduce platelet activity mediated by nitric oxide. Moreover, wine phenolics increase vitamin E levels while decreasing the oxidation of platelets submitted to oxidative stress. However, a rebound phenomenon of hyperaggregability is observed after an acute alcohol consumption which is not observed with wine consumption. This protection afforded by wine has been duplicated in animals with grape phenolics added to alcohol. The rebound phenomenon may explain ischemic strokes or sudden deaths known to occur after episodes of drunkenness. It appears that wine, and wine phenolics in particular, could have a more significant inhibitory effect on platelet aggregation and could explain, in part, the hypothesis that red wine is more protective against atherosclerosis and coronary heart disease.     

The viable but non-culturable state of wine micro-organisms during storage

Colony counting and DEFT did not give the same results when wine micro-organisms were enumerated. Both methods were used to monitor the population of acetic acid bacteria (AAB) and lactic acid bacteria (LAB) during wine storage. Results suggest that part of the populations had reached a viable but non-culturable (VBNC) state. These cells were unable to produce colonies but could hydrolyse fluorescent esters and could be counted by DEFT. For AAB, O2 deprivation quickly induced this state. Recovery from this state was very rapid as soon as O2 was available. The response was not so clear for LAB during wine storage. However, a similar state was induced by sulfiting. Moreover, filtration of wine stored in barrels and contaminated by Brettanomyces, AAB and LAB demonstrated that cell size was not homogeneous. Cells which remained in wine after several weeks could pass through a 0.45-microm membrane. However, when they re-entered a growing phase, they were again retained by membrane filtration. During and after the decline phase, wine micro-organisms might survive as smaller cells in a VBNC state.     

Strategies and perspectives for genetic improvement of wine yeasts

Recent developments in expression profile and proteomic techniques illustrated that the main oenological traits of wine yeasts are complex and influenced by several genes, each of them identified as absolutely essential. Only for monogenic properties the genetic improvement programmes of wine yeasts can be performed by alteration of individual genes. Ideally the most productive way of improving the whole-cell biocatalysts is by evolution of the entire cell genome. In this article we briefly review the main genetic improvement techniques applied in new and optimised wine strains construction, paying particular attention to blind and whole genome strategies, such as the sexual recombination and genome shuffling.     

Truth in wine yeast

Evolutionary history and early association with anthropogenic environments have made Saccharomyces cerevisiae the quintessential wine yeast. This species typically dominates any spontaneous wine fermentation and, until recently, virtually all commercially available wine starters belonged to this species. The Crabtree effect, and the ability to grow under fully anaerobic conditions, contribute decisively to their dominance in this environment. But not all strains of Saccharomyces cerevisiae are equally suitable as starter cultures. In this article, we review the physiological and genetic characteristics of S. cerevisiae wine strains, as well as the biotic and abiotic factors that have shaped them through evolution. Limited genetic diversity of this group of yeasts could be a constraint to solving the new challenges of oenology. However, research in this field has for many years been providing tools to increase this diversity, from genetic engineering and classical genetic tools to the inclusion of other yeast species in the catalogues of wine yeasts. On occasion, these less conventional species may contribute to the generation of interspecific hybrids with S. cerevisiae. Thus, our knowledge about wine strains of S. cerevisiae and other wine yeasts is constantly expanding. Over the last decades, wine yeast research has been a pillar for the modernisation of oenology, and we can be confident that yeast biotechnology will keep contributing to solving any challenges, such as climate change, that we may face in the future.     

江米酒中凝乳酶产生菌的分离及产酶条件的优化

江米酒是我国南方的一种传统食品, 江米酒中微生物所产凝乳酶具有凝乳作用。从江米酒中分离纯化得到4株菌, 经菌落分离计数和酪蛋白平板实验研究确定产凝乳酶的优势菌为其中的霉菌, 并对该霉菌产凝乳酶条件进行了初步优化, 结果表明: 2倍浓度的PDA培养基中添加5%葡萄糖而不添加氮源是霉菌产凝乳酶的最佳培养基, 在此条件下其所产凝乳酶活力可比优化前提高144%。     

Oxidative Modulation of the Glutathione-redox Couple Enhances Lipopolysaccharide-induced Interleukin 12 P40 Production by a Mouse Macrophage Cell Line,J774A.1

Abstract

Reactions of salivary nitrite with components of wine were studied using an acidic mixture of saliva and wine. The formation of nitric oxide (NO) in the stomach after drinking wine was observed. The formation of NO was also observed in the mixture (pH 3.6) of saliva and wine, which was prepared by washing the oral cavity with wine. A part of the NO formation in the stomach and the oral cavity was due to the reduction of salivary nitrite by caffeic and ferulic acids present in wine. Ethyl nitrite produced by the reaction of salivary nitrite and ethyl alcohol in wine also contributed to the formation of NO. In addition to the above reactions, caffeic acid in wine could be transformed to the oxathiolone derivative, which might have pharmacological functions. The results obtained in this study may help in understanding the effects of drinking wine on human health.