Fermentation kinetics including product and substrate inhibitions plus biomass death: a mathematical analysis

Fermentation is generally modelled by kinetic equations giving the time evolutions for biomass, substrate, and product concentrations. Although these equations can be solved analytically in simple cases if substrate/product inhibition and biomass death are included, they are typically solved numerically. We propose an analytical treatment of the kinetic equations --including cell death and an arbitrary number of inhibitions-- in which constant yield needs not be assumed. Equations are solved in phase space, i.e. the biomass concentration is written explicitly as a function of the substrate concentration.Comment: 4 pages, 4 figure

Soap-scented oil skin patch in the treatment of fibromyalgia: A case series

Treatment for fibromyalgia is largely empiric and supportive, and favors a multidisciplinary approach. Despite treatment, symptomatic relief is often inadequate and temporary. Over 90% of fibromyalgia patients seek alternative medical care. There is much anecdotal evidence that applying a bar of soap to the skin can relieve leg cramps. Expanding on this idea, I created a skin patch from soap-scented oil, which was used to treat muscular pain and spasms. After receiving positive feedback from several patients, I hypothesized that the scent of the oil itself, applied directly to the skin, is responsible for the pain-relieving and muscle-relaxant properties of the skin patch. Furthermore, I hypothesize that this soap-scented oil skin patch is an effective treatment for the pain associated with fibromyalgia

Proline content of grapes and wines

The proline, ammonia and total nitrogen content of some California grapes and the praline, total free amino acids and total nitrogen of the wines have been measured. The juice contains the predominant amount of the proline (50 to 80 %) in the grape cluster ; while the skins and seeds contain in excess of 50 % of the total nitrogen. Very little proline is found in the stems. A moderate portion is in the pulp (5 to 20 %). The praline can make up from 5 to 43 % of the total nitrogen in the juice depending o n vari ety and on grape m aturity. The Cabernet family of grapes appears to have highest percentages of prnline. A large percentage of the total amino acid left in the wine is in the form of proline. The amount of proline in the wine can vary from O to about 90 % of the total nitrogen. The wines with larger amounts of total nitrogen have higher percentages of residual proline. Rootstock affects the amount of total nitrogen but does not appear to affect the ratio of proline to total nitrogen. Th e ranges found in California grape juices range from 304 to 4600 mg/l of proline and in the wines from O to 3400 mg/l of proline. The average proline value for 78 juices was calculated as 742 mg/l and for the tabul ated data of 42 wines (from mainly cool climate grapes) - one half fermented on the skins the other half not - an average value of 869 mg/l of proline was found

Bioinformatic approaches for the genetic and phenotypic characterization of a Saccharomyces cerevisiae wine yeast collection

The objective of the present study was to compare genetic and phenotypic variation of 103 Saccharomyces cerevisiae strains isolated from winemaking environments. We used bioinformatics approaches to identify genetically similary strains with specific phenotypes and to estimate a strain's biotechnological potential. 
A S. cerevisiae collection, comprising 440 strains that were obtained from winemaking environments in Portugal has been constituted during the last years. All strains were genetically characterized by a set of eleven highly polymorphic microsatellites and showed unique allelic combinations. Using neural networks, a subset of 103 genetically most diverse strains was chosen for phenotypic analysis, that included growth in synthetic must media at various temperatures, utilization of carbon sources (glucose, ribose, arabinose, xylose, saccharose, galactose, rafinose, maltose, glycerol, potassium acetate and pyruvic acid), growth in ethanol containing media, evaluation of osmotic and oxidative stress resistance, H2S production and utilization of different nitrogen sources. Using supervised data mining approaches we have found that genotype represented with presence/absence of eleven microsatellites relates well with geographical location (performance evaluation using leave-out-out technique resulted in high performance scores; e.g., area under ROC curve was above 0.8 for a number of standard machine learning approaches tested). To find relations between phenotypes and genotypes, we used a two-step approach which first hierarchically clusters the strains according to their phenotype, and then tests if the resulting sub-clusters are identifiable using strain’s genetic data. Several groups of strains with similar phenotype profiles and common features in genotype were identified this way, and they are subject to further investigations. 

Financially supported by the programs POCI 2010 (FEDER/FCT, POCTI/AGR/56102/2004) and AGRO (ENOSAFE, Nº 762).
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Foreword: Somebody’s Watching Me: Surveillance and Privacy in an Age of National Insecurity

Forward to the Institute for Global Security Law and Policy at Case Western Reserve University symposium Somebody\u27s Watching Me: Surveillance and Privacy in an Age of National Insecurity, Cleveland, OH, October 22-23, 200

Volatile amines in Vitis vinifera varieties and changes during maturation

Changes in the volatile amines of Vitis vinifera var. Cabernet Sauvignon and var. Chenin blanc during maturation were measured at weekly intervals from veraison to maturity. The amine concentration changes during maturation for both varieties followed the same general trends. Methylamine and 2-phenethylamine were high early in the season and dropped to much lower levels during maturation. Ethylamine concentration showed substantial increases. The dimethylamine and isoamylamine showed no significant trends in concentration during the sampling period. The diethylamine concentration increased midseason for Cabernet Sauvignon samples and then decreased, but remained fairly constant for Chenin blanc samples. At maturity, freerun juice of Cabernet Sauvignon, Chenin blanc, White Riesling and Pinot noir had 500, 180, 850, and 145 μg/l of methylamine, 45, 10, 25 and 35 μg/l of dimethylamine, 610, 150, 1900 and 4900 μg/l of ethylamine, 30, 25, < 1 and 30 μg/l of diethylamine, 2, 5, 700 and 160 μg/l of isoamylamine, 4, < 1, 200 and 25 μg/l of 2-phenethylamine, < 1, < 1, < 1, and 3 μg/l of 2-methyl-1-butylamine (a-amyl) and < 1, < 1 μg/l n-propylamine (Cabernet Sauvignon and Chenin blanc only), respectively.Flüchtige Amine in Vitis-vinifera-Sorten und ihre Veränderungen während der BeerenreifeBei den Vitis-vinifera-Sorten Cabernet Sauvignon und Chenin blanc wurden die Konzentrationsänderungen der flüchtigen Amine vom Weichwerden der Beeren bis zur Beerenreife in wöchentlichen Intervallen bestimmt. Diese Veränderungen wiesen bei beiden Sorten grundsätzlich die gleiche Tendenz auf. Zu Beginn der Beerenreife waren die Methylamin- und 2-Phenäthylaminkonzentrationen hoch; während der Reife fielen sie auf erheblich niedrigere Werte ab. Die Äthylaminkonzentration stieg beträchtlich an. Dimethylamin und Isoamylamin zeigten keine klare Tendenz. Die Diäthylkonzentration war bei Cabernet Sauvignon in der Mitte der Reifeperiode am höchsten, bei Chenin blanc dagegen über den ganzen Untersuchungszeitraum recht konstant. Bei der Beerenreife lagen im nichtgepreßten Most von Cabernet Sauvignon, Chenin blanc, Weißem Riesling und Pinot noir folgende Aminkonzentrationen (in μg/l) vor: Methylamin - 500, 180, 850 und 145; Dimethylamin - 45, 10, 25, 35; Äthylamin - 610, 150, 1900, 4900; Diäthylamin - 30, 25, < 1, 30; Isoamylamin - 2, 5, 700, 160; 2-Phenäthylamin - 4, < 1, 200, 25; 2-Methyl-1-butylamin (a-Amylamin) - < 1, < 1, < 1, 3; n-Propylamin- < 1, < 1 (für Riesling und Pinot noir nicht bestimmt)

Changes in Non-Volatile Compounds and Extracts of Wines Due to Yeast Species and Fermentation Temperature

The real reducing sugar-free extracts and the calculated extracts of wines vary significantly with fermentation temperature within the range of l2°-2l°C. Relevant compositional changes are shown and discussed. The three yeasts used did not cause any significant difference in the calculated extracts. The conclusions were that any critical assessment of wine or juice amelioration based only on these forumulas would be subject to criticism