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Sample records for brewers yeast

  1. EFFECTS OF MILLET MALT WORT ON BREWER'S YEAST

    African Journals Online (AJOL)

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    The effect of PeJr ~fillet. Penniserum americanum (L), malt won obtained by modified infusion method of mashmg was investigated on the brewers yeast, Saccharomyces uvarum, growth and fermentation performance. Bud formation in the yeast was observed nine hows into the initiation of. the fermentation process which ...

  2. Genetic improvement of brewer's yeast: current state, perspectives and limits.

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    Saerens, Sofie M G; Duong, C Thuy; Nevoigt, Elke

    2010-05-01

    Brewer's yeast strain optimisation may lead to a more efficient beer production process, better final quality or healthier beer. However, brewer's yeast genetic improvement is very challenging, especially true when it comes to lager brewer's yeast (Saccharomyces pastorianus) which contributes to 90% of the total beer market. This yeast is a genetic hybrid and allopolyploid. While early studies applying traditional genetic approaches encountered many problems, the development of rational metabolic engineering strategies successfully introduced many desired properties into brewer's yeast. Recently, the first genome sequence of a lager brewer's strain became available. This has opened the door for applying advanced omics technologies and facilitating inverse metabolic engineering strategies. The latter approach takes advantage of natural diversity and aims at identifying and transferring the crucial genetic information for an interesting phenotype. In this way, strains can be optimised by introducing "natural" mutations. However, even when it comes to self-cloned strains, severe concerns about genetically modified organisms used in the food and beverage industry are still a major hurdle for any commercialisation. Therefore, research efforts will aim at developing new sophisticated screening methods for the isolation of natural mutants with the desired properties which are based on the knowledge of genotype-phenotype linkage.

  3. Yeast flocculation: what brewers should know.

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    Verstrepen, K J; Derdelinckx, G; Verachtert, H; Delvaux, F R

    2003-05-01

    For many industrial applications in which the yeast Saccharomyces cerevisiae is used, e.g. beer, wine and alcohol production, appropriate flocculation behaviour is certainly one of the most important characteristics of a good production strain. Yeast flocculation is a very complex process that depends on the expression of specific flocculation genes such as FLO1, FLO5, FLO8 and FLO11. The transcriptional activity of the flocculation genes is influenced by the nutritional status of the yeast cells as well as other stress factors. Flocculation is also controlled by factors that affect cell wall composition or morphology. This implies that, during industrial fermentation processes, flocculation is affected by numerous parameters such as nutrient conditions, dissolved oxygen, pH, fermentation temperature, and yeast handling and storage conditions. Theoretically, rational use of these parameters offers the possibility of gaining control over the flocculation process. However, flocculation is a very strain-specific phenomenon, making it difficult to predict specific responses. In addition, certain genes involved in flocculation are extremely variable, causing frequent changes in the flocculation profile of some strains. Therefore, both a profound knowledge of flocculation theory as well as close monitoring and characterisation of the production strain are essential in order to gain maximal control over flocculation. In this review, the various parameters that influence flocculation in real-scale brewing are critically discussed. However, many of the conclusions will also be useful in various other industrial processes where control over yeast flocculation is desirable.

  4. Genome annotation of a Saccharomyces sp. lager brewer's yeast

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    Patricia Marcela De León-Medina

    2016-09-01

    Full Text Available The genome of lager brewer's yeast is a hybrid, with Saccharomyces eubayanus and Saccharomyces cerevisiae as sub-genomes. Due to their specific use in the beer industry, relatively little information is available. The genome of brewing yeast was sequenced and annotated in this study. We obtained a genome size of 22.7 Mbp that consisted of 133 scaffolds, with 65 scaffolds larger than 10 kbp. With respect to the annotation, 9939 genes were obtained, and when they were submitted to a local alignment, we found that 53.93% of these genes corresponded to S. cerevisiae, while another 42.86% originated from S. eubayanus. Our results confirm that our strain is a hybrid of at least two different genomes.

  5. Brewer's yeast efficiently degrades phytate phosphorus in a corn-soybean meal diet during soaking treatment.

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    Chu, Gyo-Moon; Ohmori, Hideyuki; Kawashima, Tomoyuki; Funaba, Masayuki; Matsui, Tohru

    2009-08-01

    Microbes such as yeast and Aspergillus are known to produce phytase, and Aspergillus phytase has been used as a feed additive for improving phytate-phosphorus bioavailability in monogastric animals. We measured phytase activity in some by-products from fermented food and beverage productions by yeast and Aspergillus. The phytase activity was as high as 3577 and 2225 PU/kg DM in raw and dried brewer's yeasts, respectively. On the other hand, the phytase activity was approximately 400 PU/kg DM in white-wine yeast and red-wine yeast. The phytase activity was further low in natto (fermented soybean) residue, soy sauce cake, rice brewer's grain and the activity was not detected in dried corn-barley distiller's grain with soluble and sweet-potato distiller's residue. The stability of phytase against pepsin was much lower in the brewer's yeast than in an Aspergillus phytase preparation. On the other hand, the addition of raw brewer's yeast effectively degraded phytate phosphorus in a corn-soybean meal diet during soaking. These results suggest that phytase in the examined by-products is not suitable for the phytase source of conventional diets, but that the soaking treatment with a raw brewer's yeast is an alternative method for improving phytate-phosphorus bioavailability in corn-soybean meal diets for pigs.

  6. Defective quiescence entry promotes the fermentation performance of bottom-fermenting brewer's yeast.

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    Oomuro, Mayu; Kato, Taku; Zhou, Yan; Watanabe, Daisuke; Motoyama, Yasuo; Yamagishi, Hiromi; Akao, Takeshi; Aizawa, Masayuki

    2016-11-01

    One of the key processes in making beer is fermentation. In the fermentation process, brewer's yeast plays an essential role in both the production of ethanol and the flavor profile of beer. Therefore, the mechanism of ethanol fermentation by of brewer's yeast is attracting much attention. The high ethanol productivity of sake yeast has provided a good basis from which to investigate the factors that regulate the fermentation rates of brewer's yeast. Recent studies found that the elevated fermentation rate of sake Saccharomyces cerevisiae species is closely related to a defective transition from vegetative growth to the quiescent (G0) state. In the present study, to clarify the relationship between the fermentation rate of brewer's yeast and entry into G0, we constructed two types of mutant of the bottom-fermenting brewer's yeast Saccharomyces pastorianus Weihenstephan 34/70: a RIM15 gene disruptant that was defective in entry into G0; and a CLN3ΔPEST mutant, in which the G1 cyclin Cln3p accumulated at high levels. Both strains exhibited higher fermentation rates under high-maltose medium or high-gravity wort conditions (20° Plato) as compared with the wild-type strain. Furthermore, G1 arrest and/or G0 entry were defective in both the RIM15 disruptant and the CLN3ΔPEST mutant as compared with the wild-type strain. Taken together, these results indicate that regulation of the G0/G1 transition might govern the fermentation rate of bottom-fermenting brewer's yeast in high-gravity wort. Copyright © 2016 The Society for Biotechnology, Japan. Published by Elsevier B.V. All rights reserved.

  7. Role of bottom-fermenting brewer's yeast KEX2 in high temperature resistance and poor proliferation at low temperatures.

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    Yamagishi, Hiromi; Ohnuki, Shinsuke; Nogami, Satoru; Ogata, Tomoo; Ohya, Yoshikazu

    2010-08-01

    Variants of bottom-fermenting brewer's yeast that grew at high temperatures and showed poor proliferation and fermentation at low temperatures were isolated. Similar variants of laboratory yeast were also isolated and found to be incapable of mating. The KEX2 gene was cloned by complementation. It was shown to be responsible for these traits, because a KEX2 disruptant of Saccharomyces cerevisiae (S. cerevisiae) laboratory yeast grew poorly at low temperatures and was resistant to high temperatures. In addition, a Saccharomyces bayanus (S. bayanus)-type KEX2 (Sb-KEX2) disruptant of bottom-fermenting brewer's yeast grew poorly at low temperatures and was resistant to high temperatures. The KEX2 gene product plays an important role in proliferation of yeast at low temperatures, which is an important trait of bottom-fermenting brewer's yeast. These findings advance our understanding of the proliferation of yeast at low temperatures, especially that of bottom-fermenting brewer's yeast.

  8. Construction of dextrin and isomaltose-assimilating brewer's yeasts for production of low-carbohydrate beer.

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    Park, Jin-Yeong; Lee, Ja-Yeon; Choi, Seung-Hyun; Ko, Hyun-Mi; Kim, Il-Chul; Lee, Hwanghee Blaise; Bai, Suk

    2014-08-01

    Most Saccharomyces spp. cannot degrade or ferment dextrin, which is the second most abundant carbohydrate in wort for commercial beer production. Dextrin-degrading brewer's bottom and top yeasts expressing the glucoamylase gene (GAM1) from Debaryomyces occidentalis were developed to produce low-carbohydrate (calorie) beers. GAM1 was constitutively expressed in brewer's yeasts using a rDNA-integration system that contained yeast CUP1 gene coding for copper resistance as a selective marker. The recombinants secreted active glucoamylase, displaying both α-1,4- and α-1,6-debranching activities, that degraded dextrin and isomaltose and consequently grew using them as sole carbon source. One of the recombinant strains expressing GAM1 hydrolyzed 96 % of 2 % (w/v) dextrin and 98 % of 2 % (w/v) isomaltose within 5 days of growth. Growth, substrate assimilation, and enzyme activity of these strains were characterized.

  9. The impact of different ale brewer's yeast strains on the proteome of immature beer.

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    Berner, Torben Sune; Jacobsen, Susanne; Arneborg, Nils

    2013-09-30

    It is well known that brewer's yeast affects the taste and aroma of beer. However, the influence of brewer's yeast on the protein composition of beer is currently unknown. In this study, changes of the proteome of immature beer, i.e. beer that has not been matured after fermentation, by ale brewer's yeast strains with different abilities to degrade fermentable sugars were investigated. Beers were fermented from standard hopped wort (13° Plato) using two ale brewer's yeast (Saccharomyces cerevisiae) strains with different attenuation degrees. Both immature beers had the same alcohol and protein concentrations. Immature beer and unfermented wort proteins were analysed by 2-DE and compared in order to determine protein changes arising from fermentation. Distinct protein spots in the beer and wort proteomes were identified using Matrix-assisted laser desorption-ionization time-of-flight mass spectrometry (MALDI-TOF-MS) and MS/MS and revealed common beer proteins, such as lipid transfer proteins (LTP1 and LTP2), protein Z and amylase-protease inhibitors. During fermentation, two protein spots, corresponding to LTP2, disappeared, while three protein spots were exclusively found in beer. These three proteins, all derived from yeast, were identified as cell wall associated proteins, that is Exg1 (an exo-β-1,3-glucanase), Bgl2 (an endo-β-1,2-glucanase), and Uth1 (a cell wall biogenesis protein). Yeast strain dependent changes in the immature beer proteome were identified, i.e. Bgl2 was present in beer brewed with KVL011, while lacking in WLP001 beer.

  10. Performance of Clarias gariepinus Fed Dried Brewer's Yeast (Saccharomyces cerevisiae) Slurry in Replacement for Soybean Meal.

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    Solomon, Shola Gabriel; Ataguba, Gabriel Arome; Itodo, Gabriel Enemona

    2017-01-01

    Following disparity of earlier results, this study tested the performance of African catfish Clarias gariepinus fed dried brewer's yeast slurry meal (DBYM) based diets. Fingerlings of C. gariepinus with pooled mean initial weight of 1.58 ± 0.01 g were stocked in hapas (1 m × 1 m × 1 m) immersed in an earthen pond at a density of 15 fish per cage. Five diets with increasing substitution of soybean meal with 25%, 50%, 75%, and 100% of dried brewer's yeast and a control without dried brewer's yeast (0% substitution) were evaluated for 8 weeks. Palatability of diets reduced with increasing levels of DBYM. Growth and utilization parameters such as weight gain, feed conversion ratio, protein efficiency ratio, and specific growth rate differed significantly (p < 0.05) among treated groups. Specific growth rate decreased with increasing substitution while the best feed conversion ratio was obtained in the diet devoid of DBYM. Protein efficiency and utilization decreased with increasing levels of DBYM. Body composition was also affected by inclusion of DBYM with significant differences (p < 0.05) being observed across the diets. The trend in body composition follows the utilization of the diets. We conclude that the optimal range of inclusion and substitution of soybean meal with DBYM in C. gariepinus feed is between 1% and 14% of dry matter.

  11. Induction, separation and identification of haploid strains from industrial brewer's yeast.

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    Xu, Weina; Wang, Jinjing; Li, Qi

    2015-01-04

    Lager brewing yeasts (Saccharomyces pastorianus), the natural hybrids of S. cerevisiae and S. eubayanus, are usually heterothallic polyploidy or aneuploidy. Their intricate ploidy is a great challenge to genetic studies and strain improvement. Haploid breeding is an effective method to overcome these difficulties. Also, haploid strains play an important role in scientific research and breeding. However, lager brewing yeasts only divide asexually and hardly bear spores under normal conditions, so it is very difficult to get haploid strains from them. In this study, we established comprehensive methods to induce, separate and identify haploid strains of industrial brewer's yeast. First, we selected efficient sporulation medium to induce the sporulation of an industrial brewer's yeast strain G-03, and ther isolated spores from vegetative cells and formed colonies on YPD plates. After that, flow cytometry was used to determine the ploidy types of the pre-judged haploid candidates. Ultimately, we analyzed the genotypes of the segregants by PCR reaction and mating test in order to get precise results. Using this protocol, we obtained 26 yeast segregants by spore isolation, and 4 of them pre-judged as haploid candidates were finally confirmed as haploid by flow cytometric analysis. Two of them were MATa and others were MATα. By scanning electron microscope (SEM), the cells of 4 haploid segregants showed similar morphology to each other but had obvious differences compared with the parent strain. Pseudohyphal growth occurred in parent cells after long-period cultivation but none was found in haploid segregants. Sporulation of industrial brewer's yeast and germination of their spores was difficult but not impossible. Nevertheless, the screening and identification of haploid segregants were more challenging.

  12. Influence of quantities of brewer yeast on the performance of Anastrepha obliqua wild females (Diptera, Tephritidae

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    Cresoni-Pereira Carla

    2001-01-01

    Full Text Available Using artificial solid diets, experiments were performed with Anastrepha obliqua (Macquart, 1835 wild females in order to verify the influence of different quantities of brewer yeast on the performance and compensation behavior to unbalanced diets ingestion. The observed parameters were egg production, ingestion, diet efficiency and survival in the reproductive phase. Results indicated that there was no compensatory ingestion to different quantities of yeast and that the diet with 12.5g of yeast provided the best performance. The absence of compensatory ingestion is discussed based on the yeast phagostimulation and on the costs involved in solid diets ingestion. The relation between the analyzed parameters and the protein quantities in the diet were discussed.

  13. Influence of quantities of brewer yeast on the performance of Anastrepha obliqua wild females (Diptera, Tephritidae)

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    Cresoni-Pereira, Carla; Zucoloto, Fernando Sergio [Universidade de Sao Paulo (USP), Ribeirao Preto, SP (Brazil). Faculdade de Filosofia, Ciencias e Letras. Dept. de Biologia

    2001-11-15

    Using artificial solid diets, experiments were performed with Anastrepha obliqua (Macquart, 1835) wild females in order to verify the influence of different quantities of brewer yeast on the performance and compensation behavior to unbalanced diets ingestion. The observed parameters were egg production, ingestion, diet efficiency and survival in the reproductive phase. Results indicated that there was no compensatory ingestion to different quantities of yeast and that the diet with 12.5g of yeast provided the best performance. The absence of compensatory ingestion is discussed based on the yeast phagostimulation and on the costs involved in solid diets ingestion. The relation between the analyzed parameters and the protein quantities in the diet were discussed. (author)

  14. Evaluation of brewers' spent grain as a novel media for yeast growth.

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    Cooray, Sachindra T; Lee, Jaslyn J L; Chen, Wei Ning

    2017-12-01

    Brewers' spent grain (BSG) is a by-product generated from the beer manufacturing industry, which is extremely rich in protein and fiber. Here we use low cost BSG as the raw material for the production of a novel growth media, through a bioconversion process utilizing a food grade fungi to hydrolyze BSG. The novel fermentation media was tested on the yeast Rhodosporidium toruloides, a natural yeast producing carotenoid. The yeast growth was analysed using the growth curve and the production of intracellular fatty acids and carotenoids. Untargeted GCMS based metabolomics was used to analyse the constituents of the different growth media, followed by multivariate data analysis. Growth media prepared using fermented BSG was found to be able to support the growth in R. toruloides (21.4 mg/ml) in comparable levels to YPD media (24.7 mg/ml). Therefore, the fermented BSG media was able to fulfill the requirement as a nitrogen source for R. toruloides growth. This media was able to sustain normal metabolomics activity in yeast, as indicated by the level of fatty acid and carotenoid production. This can be explained by the fact that, in the fermented BSG media metabolites and amino acids were found to be higher than in the unfermented media, and close to the levels in YPD media. Taken together, our study provided evidence of a growth media for yeast using BSG. This should have potential in replacing components in the current yeast culture media in a sustainable and cost effective manner.

  15. Metabolic flux and nodes control analysis of brewer's yeasts under different fermentation temperature during beer brewing.

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    Yu, Zhimin; Zhao, Haifeng; Zhao, Mouming; Lei, Hongjie; Li, Huiping

    2012-12-01

    The aim of this work was to further investigate the glycolysis performance of lager and ale brewer's yeasts under different fermentation temperature using a combined analysis of metabolic flux, glycolytic enzyme activities, and flux control. The results indicated that the fluxes through glycolytic pathway decreased with the change of the fermentation temperature from 15 °C to 10 °C, which resulted in the prolonged fermentation times. The maximum activities (V (max)) of hexokinase (HK), phosphofructokinase (PFK), and pyruvate kinase (PK) at key nodes of glycolytic pathway decreased with decreasing fermentation temperature, which was estimated to have different control extent (22-84 %) on the glycolytic fluxes in exponential or flocculent phase. Moreover, the decrease of V (max) of PFK or PK displayed the crucial role in down-regulation of flux in flocculent phase. In addition, the metabolic state of ale strain was more sensitive to the variation of temperature than that of lager strain. The results of the metabolic flux and nodes control analysis in brewer's yeasts under different fermentation temperature may provide an alternative approach to regulate glycolytic flux by changing V (max) and improve the production efficiency and beer quality.

  16. Isolation and Characterization of Brewer's Yeast Variants with Improved Fermentation Performance under High-Gravity Conditions▿

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    Blieck, Lies; Toye, Geert; Dumortier, Françoise; Verstrepen, Kevin J.; Delvaux, Freddy R.; Thevelein, Johan M.; Van Dijck, Patrick

    2007-01-01

    To save energy, space, and time, today's breweries make use of high-gravity brewing in which concentrated medium (wort) is fermented, resulting in a product with higher ethanol content. After fermentation, the product is diluted to obtain beer with the desired alcohol content. While economically desirable, the use of wort with an even higher sugar concentration is limited by the inability of brewer's yeast (Saccharomyces pastorianus) to efficiently ferment such concentrated medium. Here, we describe a successful strategy to obtain yeast variants with significantly improved fermentation capacity under high-gravity conditions. We isolated better-performing variants of the industrial lager strain CMBS33 by subjecting a pool of UV-induced variants to consecutive rounds of fermentation in very-high-gravity wort (>22° Plato). Two variants (GT336 and GT344) showing faster fermentation rates and/or more-complete attenuation as well as improved viability under high ethanol conditions were identified. The variants displayed the same advantages in a pilot-scale stirred fermenter under high-gravity conditions at 11°C. Microarray analysis identified several genes whose altered expression may be responsible for the superior performance of the variants. The role of some of these candidate genes was confirmed by genetic transformation. Our study shows that proper selection conditions allow the isolation of variants of commercial brewer's yeast with superior fermentation characteristics. Moreover, it is the first study to identify genes that affect fermentation performance under high-gravity conditions. The results are of interest to the beer and bioethanol industries, where the use of more-concentrated medium is economically advantageous. PMID:17158628

  17. Effects of wort gravity and nitrogen level on fermentation performance of brewer's yeast and the formation of flavor volatiles.

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    Lei, Hongjie; Zhao, Haifeng; Yu, Zhimin; Zhao, Mouming

    2012-03-01

    Normal gravity wort and high gravity wort with different nitrogen levels were used to examine their effects on the fermentation performance of brewer's yeast and the formation of flavor volatiles. Results showed that both the wort gravity and nitrogen level had significant impacts on the growth rate, viability, flocculation, and gene expression of brewer's yeast and the levels of flavor volatiles. The sugar (glucose, maltose, and maltotriose) consumption rates and net cell growth decreased when high gravity worts were used, while these increased with increasing nitrogen level. Moreover, high gravity resulted in lower expression levels of ATF1, BAP2, BAT1, HSP12, and TDH, whereas the higher nitrogen level caused higher expression levels for these genes. Furthermore, the lower nitrogen level resulted in increases in the levels of higher alcohols and esters at high wort gravity. All these results demonstrated that yeast physiology and flavor balance during beer brewing were significantly affected by the wort gravity and nitrogen level.

  18. The examination of parameters for lactic acid fermentation and nutritive value of fermented juice of beetroot, carrot and brewer’s yeast autolysate

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    MILAN MAKSIMOVIC

    2004-09-01

    Full Text Available The conditions for lactic acid fermentation based on a mixture of beetoot juice (Beta vulgaris L. and carrot juice (Daucus carota L. and different content of brewer’s yeast autolysate with Lactobacillus plantarum A112 and with Lactobacillus acidophilus NCDO 1748 has been studied. Both cultures showed good biochemical activity in these mixtures. The production of lactic acid has been stimulated using a higher content of brewer’s yeast autolysate. In these mixtures, L. plantarum A112 showed better growth and lactic acid production than L. acidophilus NCDO 1748. From the data obtained through chemical analyses of the fermented products, it can be seen that the mixture of beetroot and carrot juice and brewer’s yeast autolysate is richer in minerals (Ca, P, Fe and b-carotene than fermented beetroot juice with the same content of brewer’s yeast autolysate.

  19. Physiological characterization of brewer's yeast in high-gravity beer fermentations with glucose or maltose syrups as adjuncts.

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    Piddocke, Maya P; Kreisz, Stefan; Heldt-Hansen, Hans Peter; Nielsen, Kristian Fog; Olsson, Lisbeth

    2009-09-01

    High-gravity brewing, which can decrease production costs by increasing brewery yields, has become an attractive alternative to traditional brewing methods. However, as higher sugar concentration is required, the yeast is exposed to various stresses during fermentation. We evaluated the influence of high-gravity brewing on the fermentation performance of the brewer's yeast under model brewing conditions. The lager brewer's strain Weihenstephan 34/70 strain was characterized at three different gravities by adding either glucose or maltose syrups to the basic wort. We observed that increased gravity resulted in a lower specific growth rate, a longer lag phase before initiation of ethanol production, incomplete sugar utilization, and an increase in the concentrations of ethyl acetate and isoamyl acetate in the final beer. Increasing the gravity by adding maltose syrup as opposed to glucose syrup resulted in more balanced fermentation performance in terms of higher cell numbers, respectively, higher wort fermentability and a more favorable flavor profile of the final beer. Our study underlines the effects of the various stress factors on brewer's yeast metabolism and the influence of the type of sugar syrups on the fermentation performance and the flavor profile of the final beer.

  20. Energy concentration and phosphorus digestibility in yeast products produced from the ethanol industry, and in brewers' yeast, fish meal, and soybean meal fed to growing pigs.

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    Kim, B G; Liu, Y; Stein, H H

    2014-12-01

    Two experiments were conducted to determine the DE, ME, and standardized total tract digestibility (STTD) of P in 2 novel sources of yeast (C-yeast and S-yeast) and in brewers' yeast, fish meal, and soybean meal fed to growing pigs. The 2 new sources of yeast are coproducts from the dry-grind ethanol industry. The concentrations of DM, GE, and P were 94.8%, 5,103 kcal/kg, and 1.07% in C-yeast; 94.4%, 4,926 kcal/kg, and 2.01% in S-yeast; 93.6%, 4,524 kcal/kg, and 1.40% in brewers' yeast; 91.4%, 4,461 kcal/kg, and 3.26% in fish meal; and 87.7%, 4,136 kcal/kg, and 0.70% in soybean meal, respectively. The DE and ME in each of the ingredients were determined using 42 growing barrows (28.9±2.18 kg BW). A corn-based basal diet and 5 diets containing corn and 24% to 40% of each test ingredient were formulated. The total collection method was used to collect feces and urine, and the difference procedure was used to calculate values for DE and ME in each ingredient. The concentrations of DE in corn, C-yeast, S-yeast, brewers' yeast, fish meal, and soybean meal were 4,004, 4,344, 4,537, 4,290, 4,544, and 4,362 kcal/kg DM (SEM=57), respectively, and the ME values were 3,879, 3,952, 4,255, 3,771, 4,224, and 4,007 kcal/kg DM (SEM=76), respectively. The ME in S-yeast and fish meal were greater (Pyeast, whereas the ME in C-yeast and soybean meal were not different from those of any of the other ingredients. The STTD of P in the 5 ingredients was determined using 42 barrows (28.3±7.21 kg BW) that were placed in metabolism cages. Five diets were formulated to contain each test ingredient as the sole source of P, and a P-free diet was used to estimate the basal endogenous loss of P. Feces were collected for 5 d using the marker to marker method after a 5-d adaptation period. The STTD of P in brewers' yeast (85.2%) was greater (Pyeast (75.7%). The STTD of P in C-yeast (73.9%) was not different from the STTD of P in S-yeast and fish meal (67.3%) but was greater (Pyeast contain

  1. Brewer's Yeast, Saccharomyces cerevisiae, Enhances Attraction of Two Invasive Yellowjackets (Hymenoptera: Vespidae) to Dried Fruit and Fruit Powder.

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    Babcock, Tamara; Gries, Regine; Borden, John; Palmero, Luis; Mattiacci, Analía; Masciocchi, Maité; Corley, Juan; Gries, Gerhard

    2017-09-01

    The German yellowjacket, Vespula germanica F., and common yellowjacket, Vespula vulgaris L. (Hymenoptera: Vespidae), are pests of significant economic, environmental, and medical importance in many countries. There is a need for the development and improvement of attractive baits that can be deployed in traps to capture and kill these wasps in areas where they are a problem. Yellowjackets are known to feed on fermenting fruit, but this resource is seldom considered as a bait due to its ephemeral nature and its potential attractiveness to nontarget species. We analyzed the headspace volatiles of dried fruit and fruit powder baits with and without Brewer's yeast, Saccharomyces cerevisiae, using gas chromatography-mass spectrometry, and we field tested these baits for their attractiveness to yellowjackets in Argentina. The addition of yeast to dried fruit and fruit powder changed the volatile compositions, increasing the number of alcohols and acids and decreasing the number of aldehydes. Dried fruit and fruit powder baits on their own were hardly attractive to yellowjackets, but the addition of yeast improved their attractiveness by 9- to 50-fold and surpassed the attractiveness of a commercial heptyl butyrate-based wasp lure. We suggest that further research be done to test additional varieties and species of yeasts. A dried fruit or fruit powder bait in combination with yeast could become a useful tool in the management of yellowjackets. © The Author 2017. Published by Oxford University Press on behalf of Entomological Society of America.

  2. Effect of the production or use of mixtures of bakers’ or brewers’ yeast extracts on their ability to promote growth of lactobacilli and pediococci

    OpenAIRE

    Champagne,Claude P; Gaudreau,Hélène; Conway,John

    2003-01-01

    Three brewers’ and three bakers’ yeast extracts (YE) were obtained from five commercial suppliers. They were added to microbiological media and their growth-promoting properties were examined using four lactic cultures (Lactobacillus casei EQ28 and EQ85, Lactobacillus acidophilus EQ57, Pediococcus acidilactici MA18/5-M). Bakers’ YE have a higher total nitrogen content than brewers’ YE, but there was not always a correlation between the nitrogen content and growth. A systematic preference for ...

  3. Quantification of brewers' yeast flocculation in a stirred tank: effect of physical parameters on flocculation.

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    van Hamersveld, E H; van der Lans, R G; Luyben, K C

    1997-10-20

    Quantification of yeast flocculation under defined conditions will help to understand the physical mechanisms of the flocculation process used in beer fermentation. Flocculation was quantified by measuring the size of yeast flocs and the number of single cells. For this purpose, a method to measure floc size and number of single cells in situ was developed. In this way, it was possible to quantify the actual flocculation during fermentation, without influencing flocculation. The effects of three physical parameters, floc strength, fluid shear, and yeast cell concentration, on flocculation during beer fermentation, were examined. Increasing floc strength results in larger flocs and lower numbers of single cells. If the fluid shear is increased, the size of the flocs decreases, and the number of single cells remains constant at approximately 10% of the total cells present. The cell concentration also influences flocculation, a reduction of 50% in cell concentration leads to a decrease of about 25% in floc size. The number of single cells decreases in linear proportion to the cell concentration. This means that, during yeast settling at full scale, the number of single cells decreases. The results of this study are used in a model for yeast flocculation. With respect to full scale fermentation the effect of cell concentration will play an important role, for flocculation and sedimentation will occur simultaneously leading to a quasi steady state between these phenomena. (c) 1997 John Wiley & Sons, Inc. Biotechnol Bioeng 56: 190-200, 1997.

  4. The lager yeast Saccharomyces pastorianus removes and transforms Fusarium trichothecene mycotoxins during fermentation of brewer's wort.

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    Nathanail, Alexis V; Gibson, Brian; Han, Li; Peltonen, Kimmo; Ollilainen, Velimatti; Jestoi, Marika; Laitila, Arja

    2016-07-15

    An investigation was conducted to determine the fate of deoxynivalenol, deoxynivalenol-3-glucoside, HT-2 toxin and T-2 toxin, during a four-day fermentation with the lager yeast Saccharomyces pastorianus. The influence of excessive mycotoxin concentrations on yeast growth, productivity and viability were also assessed. Mycotoxins were dosed at varying concentrations to 11.5° Plato wort. Analysis of yeast revealed that presence of the toxins even at concentrations up to 10,000 μg/L had little or no effect on sugar utilisation, alcohol production, pH, yeast growth or cell viability. Of the dosed toxin amounts 9-34% were removed by the end of fermentation, due to physical binding and/or biotransformation by yeast. Deoxynivalenol-3-glucoside was not reverted to its toxic precursor during fermentation. Processing of full-scan liquid chromatography-quadrupole time-of-flight-mass spectrometry (LC-QTOF-MS) data with MetaboLynx and subsequent LC-QTOF-MS/MS measurements resulted in annotation of several putative metabolites. De(acetylation), glucosylation and sulfonation were the main metabolic pathways activated. Copyright © 2016 Elsevier Ltd. All rights reserved.

  5. Preparation and characteristics of beta-glucan concentrate from brewer's yeast as the additive substance in foods

    Directory of Open Access Journals (Sweden)

    Ľubomír Mikuš

    2013-02-01

    Full Text Available Normal 0 21 false false false SK X-NONE X-NONE The brewer¢s yeast was used for preparation of concentrate with content of β-glucan. Hot water extraction (100°C, 5 hours and subsequently an alkaline extraction of sediment using 1 M NaOH at 90°C for 1 hour were used. β-glucan concentrate containing 59,15 % of β-glucan had good functional properties (water binding capacity 13,34 g water/1 g concentrate, fat binding capacity 6,86 g fat/1 g concentrate and indicated biological action too.  At concentration of 2 mg/ml DMSO (dimethylsulfoxid was viability of murine L1210 leukemic cells reduced to 76.15 %. When observing the antioxidant activity it was identified, that the lipid peroxidation in linoleic acid samples was decreased during the presence of β-glucan concentrate. These results and good sensory properties like a bright colour and the pleasant taste and smell indicate, that prepared β-glucan concentrate has a potential to be used to improve the health – beneficial substances in the foods.doi:10.5219/258

  6. Identification and Characterization of Phospholipids with Very Long Chain Fatty Acids in Brewer's Yeast

    Czech Academy of Sciences Publication Activity Database

    Řezanka, Tomáš; Kolouchová, I.; Gharwalová, L.; Palyzová, Andrea; Sigler, Karel

    2017-01-01

    Roč. 52, č. 12 (2017), s. 1007-1017 ISSN 0024-4201 R&D Projects: GA ČR(CZ) GA17-00027S Institutional support: RVO:61388971 Keywords : Yeast * Very long chain fatty acids * Negative electrospray ionization Subject RIV: EE - Microbiology, Virology Impact factor: 1.934, year: 2016

  7. Beneficial Effect of Brewers' Yeast Extract on Daily Activity in a Murine Model of Chronic Fatigue Syndrome

    Directory of Open Access Journals (Sweden)

    Takashi Takahashi

    2006-01-01

    Full Text Available The aim of this study was to assess the effect of Brewers' yeast extract (BYE on daily activity in a mouse model of chronic fatigue syndrome (CFS. CFS was induced by repeated injection of Brucella abortus (BA antigen every 2 weeks. BYE was orally administered to mice in a dose of 2 g per kg per day for 2 weeks before injecting BA and for 4 weeks thereafter. We evaluated daily running activity in mice receiving BYE as compared with that in untreated mice. Weekly variation of body weight (BW and survival in both groups was monitored during the observation period. Spleen weight (SW, SW/BW ratio, percent splenic follicular area and expression levels of interferon-γ (IFN-γ and interleukin-10 (IL-10 mRNA in spleen were determined in both groups at the time of sacrifice. The daily activity during 2 weeks after the second BA injection was significantly higher in the treated group than in the control. There was no difference in BW between both groups through the experimental course. Two mice in the control died 2 and 7 days after the second injection, whereas no mice in the treated group died. Significantly decreased SW and SW/BW ratio were observed in the treated mice together with elevation of splenic follicular area. There were suppressed IFN-γ and IL-10 mRNA levels in spleens from the treated mice. Our results suggest that BYE might have a protective effect on the marked reduction in activity following repeated BA injection via normalization of host immune responses.

  8. Effects of graded levels of liquid brewer's yeast on chemical composition and fermentation quality in cassava pulp and rice straw-based total mixed ration silage.

    Science.gov (United States)

    Kamphayae, Sukanya; Kumagai, Hajime; Bureenok, Smerjai; Narmseelee, Ramphrai; Butcha, Patima

    2017-04-01

    This study aimed to evaluate the effect of liquid brewer's yeast (LBY) addition on chemical composition and fermentation quality of mixture of LBY and cassava pulp (CVP) with rice straw (RS) in different ratios during preservation periods. Four mixtures of LBY, CVP and RS were made, that is mixture ratio of LBY : CVP : RS of 0% LBY, 20% LBY, 35% LBY and 50% LBY were 0:70:30, 20:50:30, 35:35:30 and 50:20:30 as fresh matter, respectively. The bags were opened at weeks 0, 1, 2, 4 and 8 after storage. The contents of dry matter, organic matter, crude protein (CP), ether extract (EE), neutral detergent fiber and acid detergent fiber ranged 36.4-40.0, 88.9-90.8, 4.0-12.0, 1.1-1.3, 58.8-61.6 and 37.6-40.0, respectively, and the contents of CP and EE increased and the other components decreased in proportion to LBY inclusion (P fermentation quality during longer storage periods. © 2016 Japanese Society of Animal Science.

  9. Reduced production of diacetyl by overexpressing BDH2 gene and ILV5 gene in yeast of the lager brewers with one ILV2 allelic gene deleted.

    Science.gov (United States)

    Shi, Ting-Ting; Li, Ping; Chen, Shi-Jia; Chen, Ye-Fu; Guo, Xue-Wu; Xiao, Dong-Guang

    2017-03-01

    Diacetyl causes an unwanted buttery off-flavor in lager beer. The production of diacetyl is reduced by modifying the metabolic pathway of yeast in the beer fermentation process. In this study, BDH2 and ILV5 genes, coding diacetyl reductase and acetohydroxy acid reductoisomerase, respectively, were expressed using a PGK1 promoter in Saccharomyces cerevisiae, which deleted one ILV2 allelic gene. Diacetyl contents and fermentation performances were examined and compared. Results showed that the diacetyl content in beer was remarkably reduced by 16.52% in QI2-KP (one ILV2 allelic gene deleted), 55.65% in QI2-B2Y (overexpressed BDH2 gene and one ILV2 allelic gene deleted), and 69.13% in QI2-I5Y (overexpressed ILV5 gene and one ILV2 allelic gene deleted) compared with the host strain S2. The fermentation ability of mutant strains was similar to that of S2. Results of the present study can lead to further advances in this technology and its broad application in scientific investigations and industrial beer production.

  10. 77 FR 72999 - Small Brewers Bond Reduction

    Science.gov (United States)

    2012-12-07

    ... be difficult for small brewers to fully understand and use to their best advantage. Accordingly, TTB... made in English, be legible, and be written in language acceptable for public disclosure. TTB does not...

  11. 27 CFR 28.225 - Removals of beer by brewer.

    Science.gov (United States)

    2010-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 1 2010-04-01 2010-04-01 false Removals of beer by brewer..., DEPARTMENT OF THE TREASURY LIQUORS EXPORTATION OF ALCOHOL Exportation of Beer With Benefit of Drawback Execution of Claims § 28.225 Removals of beer by brewer. Where a brewer removes taxpaid beer from the...

  12. SILAGE CANE SUGAR ADDED WITH DRIED BREWER

    Directory of Open Access Journals (Sweden)

    W. J. R. Castro

    2015-02-01

    Full Text Available The objective of this experiment was to evaluate the fermentative parameters and chemical composition of silage cane sugar added with residue dried brewery. The experimental design was completely randomized with four treatments and four replications: 100% cane sugar; 90% of cane sugar + 10% residue dried brewer; 80% of cane sugar + 20% residue dried brewer and 70% cane sugar + 30% dried brewer based on natural matter, composed silages. The sugar cane was chopped in a stationary machine with forage particle size of approximately 2 cm, and homogenized manually with the additives. For storage chopped fresh weight were used in experimental silos capacity of about 4 liters. The results showed that the contents of dry matter and crude protein showed positive linear (P0.05 with mean value of 3.81, while for ether extract and ash results were positive linear (P0.05 for N ammonia presented average value of 4.18. It is concluded that the addition of brewer dehydrated improves the fermentation process of silage cane sugar, in addition to improving their nutritional characteristics.

  13. Mycobiota and mycotoxins in malted barley and brewer's spent grain from Argentinean breweries.

    Science.gov (United States)

    Gonzalez Pereyra, M L; Rosa, C A R; Dalcero, A M; Cavaglieri, L R

    2011-12-01

    To evaluate mycobiota and aflatoxins B(1) (AFB(1)), B(2) (AFB(2)), G(1) (AFG(1)), G(2) (AFG(2)) and fumonisin B(1) (FB(1)) contamination in different malted barley types and brands and brewer's grain collected from a major Argentinean brewery. Total fungal counts were performed using the plate count method. Aflatoxin B(1), AFB(2), AFG(1), AFG(2) and Zearalenone (ZEA) analyses were performed by thin-layer chromatography (TLC). Fumonisin B(1) was determined by HPLC. Eighty-three percentage of the malted barley (100% M1, 50% M2 and 100% M3) and 61% of brewer's grain samples had a count >1 × 10(4) CFU g(-1). Yeasts were isolated from all malt and brewer's grain samples. Genera containing some of the most important mycotoxin producer species--Fusarium ssp., Aspergillus ssp., Penicillium ssp. and Alternaria ssp.--were isolated from the analysed samples, along with other environmental saprophytic fungi such as Geotrichum ssp., Mucorales and Cladosporium ssp. All samples were contaminated with 104-145 μg kg(-1) FB(1). Eighteen per cent of brewer's grain samples were contaminated with 19-44.52 μg kg(-1) AFB(1). Aflatoxin B(2), AFG(1), AFG(2) and ZEA were not detected in any of the analysed samples. Fungal and mycotoxin contamination in malt and brewer's grain is an actual risk for animal and human health. This study may be useful for assessing the risk of mycotoxins in Argentinean beers and especially in animal feeds. © 2011 The Authors. Letters in Applied Microbiology © 2011 The Society for Applied Microbiology.

  14. Brewer spectrophotometer measurements in the Canadian Arctic

    Science.gov (United States)

    Kerr, J. B.; Evans, W. F. J.

    1988-01-01

    In the winters of 1987 and 1988 measurements were conducted with the Brewer Spectrophotometer at Alert (82.5 N) and Resolute (74.5 N). The measurements were conducted as part of our Canadian Program to search for an Arctic Ozone Hole (CANOZE). Ozone measurements were conducted in the months of December, January and February using the moon as a light source. The total ozone measurements will be compared with ozonesonde profiles, from ECC sondes, flown once per week from Alert and Resolute. A modified Brewer Spectrophotometer was used in a special study to search for chlorine dioxide at Alert in March 1987. Ground based observations at Saskatoon in February and at Alert in March 1987 failed to detect any measureable chlorine dioxide. Interference from another absorbing gas, which we speculate may be nitrous acid, prevented the measurements at the low levels of chlorine dioxide detected in the Southern Hemisphere by Solomon et al.

  15. EFFECTS OF MILLET MALT WORT ON BREWER'S YEAST

    African Journals Online (AJOL)

    BSN

    unconverted starch was detem1ined using AOAC method (1980) by addition of 0.2M iodine solution to the liquor. Total acidity measured as acetic acid was determined by titrating the wort to end point with sodium hydroxide using phenolphthalein indicator (Pearson, 1976). The alcohol percent (V/V) was determined by the ...

  16. Brewer, Maine Wastewater Treatment Plant Recognized for Excellence

    Science.gov (United States)

    The Brewer Water Pollution Control Facility was recently honored with a 2015 Regional Wastewater Treatment Plant Excellence Award by the US Environmental Protection Agency's New England regional office.

  17. Bioavailability of selenium from fish, yeast and selenate: A comparative study in humans using stable isotopes

    NARCIS (Netherlands)

    Fox, T.E.; Heuvel, E.G.H.M. van den; Atherton, C.A.; Dainty, J.R.; Lewis, D.J.; Langford, N.J.; Crews, H.M.; Luten, J.B.; Lorentzen, M.; Sieling, F.W.; Aken-Schneyder, P. van; Hoek, M.; Kotterman, M.J.J.; Dael, P. van; Firweather-Tail, S.J.

    2004-01-01

    Objective: To measure the bioavailability of selenium from cooked and raw fish in humans by estimating and comparing apparent absorption and retention of selenium in biosynthetically labelled fish with labelled selenate and biosynthetically labelled selenium in brewers yeast. Design: The

  18. Bioavailibility of selenium from fish, yeast and selenate: a comparative study in humans using stable isotopes

    NARCIS (Netherlands)

    Fox, T.E.; Heuvel, van den E.G.H.M.; Atherton, C.A.; Luten, J.B.; Hoek-van Nieuwenhuizen, van M.; Kotterman, M.J.J.

    2004-01-01

    Objective: To measure the bioavailability of selenium from cooked and raw fish in humans by estimating and comparing apparent absorption and retention of selenium in biosynthetically labelled fish with labelled selenate and biosynthetically labelled selenium in brewers yeast. Design: The

  19. Brewer's spent grain: A review of its potentials and applications ...

    African Journals Online (AJOL)

    Brewer's spent grain: A review of its potentials and applications. S Aliyu, M Bala. Abstract. Most developing nations continuously produce abundant agro-industrial residues such as brewer's spent grain (BSG), which are underexploited. BSG as the main by-product of brewing industry, representing approximately 85% of ...

  20. 27 CFR 28.227 - Removals of beer by persons other than the brewer or agent of the brewer.

    Science.gov (United States)

    2010-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 1 2010-04-01 2010-04-01 false Removals of beer by... ALCOHOL Exportation of Beer With Benefit of Drawback Execution of Claims § 28.227 Removals of beer by persons other than the brewer or agent of the brewer. Where there is a removal of taxpaid beer by a person...

  1. Hybridization of Palm Wine Yeasts ( Saccharomyces Cerevisiae ...

    African Journals Online (AJOL)

    Haploid auxotrophic strains of Saccharomyces cerevisiae were selected from palm wine and propagated by protoplast fusion with Brewers yeast. Fusion resulted in an increase in both ethanol production and tolerance against exogenous ethanol. Mean fusion frequencies obtained for a mating types ranged between 8 x ...

  2. Electrochemical and Chemical Complications Resulting from Yeast Extract Addition to Stimulate Microbial Growth

    Science.gov (United States)

    2016-09-22

    including strains of Saccharomyces cerevisiae grown on molasses-based media , debittered brewers yeasts (strains of Saccharo- myces cerevisiae or...mediators, riboflavin, yeast extract INTRODUCTION Yeast extract (YE) is routinely added to microbiolog- ical media to encourage microbial growth , including...microorganisms.1-4 YE is made by extracting yeast cells (removing the cell walls). Several yeast species and growth media are used for commercial production

  3. Hydrolysis of Brewers' Spent Grain by Carbohydrate Degrading Enzymes

    NARCIS (Netherlands)

    Forssell, P.; Kontkanen, H.; Schols, H.A.; Hinz, S.W.A.; Eijsink, V.G.H.; Treimo, J.; Robertson, J.A.; Waldron, K.W.; Faulds, C.B.; Buchert, J.

    2008-01-01

    In this work four commercial cellulase-hemicellulase mixtures with different activity profiles were used for solubilization of carbohydrates from brewers' spent grain (BSG). After the enzyme treatment, both the solubilised fraction and the unhydrolysed residue were characterized. Treatment with

  4. Brewer's spent grain and corn steep liquor as alternative culture medium substrates for proteinase production by Streptomyces malaysiensis AMT-3

    Directory of Open Access Journals (Sweden)

    Rodrigo Pires do Nascimento

    2011-12-01

    Full Text Available Brewer's spent grain and corn steep liquor or yeast extract were used as the sole organic forms for proteinase production by Streptomyces malaysiensis in submerged fermentation. The influence of the C and N concentrations, as well as the incubation periods, were assessed. Eight proteolytic bands were detected through gelatin-gel-electrophoresis in the various extracts obtained from the different media and after different incubation periods, with apparent molecular masses of 20, 35, 43, 50, 70, 100, 116 and 212 kDa. The results obtained suggest an opportunity for exploring this alternative strategy for proteinases production by actinomycetes, using BSG and CSL as economically feasible substrates.

  5. Evaluation of some properties of wheat-brewers' spent cassava flour ...

    African Journals Online (AJOL)

    brewers' spent cassava flour blends and that it has a lot of potential in the food industry especially its use as thickener and binding agent in the food systems. Keywords: Brewers' spent cassava flour, wheat flour, proximate, functional properties.

  6. Removal of heavy metals from metal-containing effluent by yeast ...

    African Journals Online (AJOL)

    Cr) and tin (Sn) from metal-containing effluent by waste brewer's yeast. Biosorption of Cr and Sn was studied under batch conditions at a pH value of 6.5. The biomass, non-viable cells of the yeast Saccharomyces cerevisiae, is able to adsorb ...

  7. Vegemite Beer: yeast extract spreads as nutrient supplements to promote fermentation.

    Science.gov (United States)

    Kerr, Edward D; Schulz, Benjamin L

    2016-01-01

    Vegemite is an iconic Australian food spread made from spent brewers' yeast extract, which has been reported to be used as an ingredient in illegal home brewing. In this study, we tested the utility of Vegemite and the similar spread Marmite in promoting fermentation. We could not culture microorganisms from either Vegemite or Marmite, consistent with these food-grade spreads being essentially sterile. To test if the addition of Vegemite or Marmite could assist in fermentation when additional viable yeast was also present, solutions containing glucose and a range of concentrations of either Vegemite or Marmite were inoculated with brewers' yeast. No fermentation occurred in any condition without addition of extra brewer's yeast. Fermentation did not occur when yeast was inoculated into solutions containing only glucose, but progressed efficiently with when Vegemite or Marmite was also added. Gas Chromatography confirmed that ethanol was present at ∼3% v/v post-fermentation in all samples which contained glucose, Vegemite or Marmite, and brewers' yeast. Trace amounts of methanol were also detected. Mass spectrometry proteomics identified abundant intracellular yeast proteins and barley proteins in Vegemite and Marmite, and abundant secreted yeast proteins from actively growing yeast in those samples to which extra brewers' yeast had been added. We estimate that the real-world cost of home brewed "Vegemite Beer" would be very low. Our results show that Vegemite or other yeast extract spreads could provide cheap and readily available sources of nutrient supplementation to increase the efficiency of fermentation in home brewing or other settings.

  8. Analysis of the hybrid genomes of brewing yeasts

    NARCIS (Netherlands)

    Bolat, I.

    2016-01-01

    One of the best guarded secrets of brewers is represented by the brewing yeast employed in beer fermentation, due to its profound impact upon the specific flavour profile of the final product. The current research tackles the genome diversity of lager brewing strains as well as their impact on

  9. Protease-induced solubilisation of carbohydrates from brewers' spent grain

    NARCIS (Netherlands)

    Faulds, C.B.; Collins, S.; Robertson, J.A.; Treimo, J.; Eijsink, V.G.H.; Hinz, S.W.A.; Schols, H.A.; Buchert, J.; Waldron, K.W.

    2009-01-01

    The impact of microbial proteases on the release of carbohydrates from BSG was studied. The proteases were able to release the non-cellulosic glucose, a portion of feruloylated arabinoxylan and over 50% of the protein from brewers' spent grain (BSG) after 24 h hydrolysis. The non-cellulosic glucose

  10. Nutritive Value of Maize/Sorghum Brewers' Dried Grains ...

    African Journals Online (AJOL)

    A 28-day feeding trial involving 81 one-week-old Anak broilers was carried out in a completely randomized design experiment to investigate the nutritive value of maize/sorghum brewers' dried grain (MSBDG) supplemented with palm oil in broiler starter diets. The diets were formulated to contain 0% levels of MSBDG ...

  11. Amino Acid Profile of Biodegraded Brewers Spent Grains (BSG ...

    African Journals Online (AJOL)

    The amino acids profiles of biodegraded brewers spent grains (BSG) were determined. The analysis revealed the presence of 17 amino acids including the major amino acids (cysteine, lysine and methionine) required in poultry nutrition. The concentrations of the amino acids however varied with the microbial species used ...

  12. Charles L. Brewer Award for Distinguished Teaching of Psychology

    Science.gov (United States)

    American Psychologist, 2009

    2009-01-01

    The American Psychological Foundation (APF) Charles L. Brewer Distinguished Teaching of Psychology Award recognizes an outstanding career contribution to the teaching of psychology. The 2009 recipient of the Distinguished Teaching Award is William Buskist. Dorothy W. Cantor, president of the APF, will present the APF Teaching Award at the 117th…

  13. Effect of replacing groundnut cake with urea fermented brewer's ...

    African Journals Online (AJOL)

    The effect o replacing groundnut cake with urea fermented brewer's dried grains at 0 25 50, 75 and 100 % graded levels in broiler chick starter diets was investigated. Five dietary treatments were formulated to be isonitrogenous and isocaloric to provide 23 % crude protein and 2900 kcal/kg metabolizable energy.

  14. Egg Quality Characteristics Of Isa – Brown Layers Fed Brewers ...

    African Journals Online (AJOL)

    Eggs laid by Isa-brown layers were used in this study to investigate the effect of partial substitution of biodegraded brewers' dried grains (BDG) for maize on egg quality parameters of laying hens. A total of 1,728 eggs were used for this study which spanned over a period of 84 days. Eggs were collected from laying birds fed ...

  15. Quality assurance of the Brewer spectral UV measurements in Finland

    Directory of Open Access Journals (Sweden)

    K. Lakkala

    2008-06-01

    Full Text Available The quality assurance of the two Brewer spectrophotometers of the Finnish Meteorological Institute is discussed in this paper. The complete data processing chain from raw signal to high quality spectra is presented. The quality assurance includes daily maintenance, laboratory characterizations, calculation of long-term spectral responsivity, data processing and quality assessment. The cosine correction of the measurements is based on a new method, and is included in the data processing software. The results showed that the actual cosine correction factor of the two Finnish Brewers can vary between 1.08–1.13 and 1.08–1.12, respectively, depending on the sky radiance distribution and wavelength. The temperature characterization showed a linear temperature dependence between the instruments' internal temperature and the photon counts per cycle, and a temperature correction was used for correcting the measurements. The long-term spectral responsivity was calculated using the time series of several lamps using two slightly different methods. The long-term spectral responsivity was scaled to the irradiance scale of the Helsinki University of Technology (HUT for the whole of the measurement time-periods 1990–2006 and 1995–2006 for Sodankylä and Jokioinen, respectively. Both Brewers have participated in many international spectroradiometer comparisons, and have shown good stability. The differences between the Brewers and the portable reference spectroradiometer QASUME have been within 5% during 2002–2007.

  16. Construction and evaluation of self-cloning bottom-fermenting yeast with high SSU1 expression.

    Science.gov (United States)

    Iijima, K; Ogata, T

    2010-12-01

    To construct a self-cloning brewer's yeast that can minimize the unfavourable flavours caused by oxidation and certain kinds of sulfur compounds. DNA fragments of a high-expression promoter from the TDH3 gene originating from Saccharomyces cerevisiae were integrated into the promoter regions of the S. cerevisiae-type and Saccharomyces bayanus-type SSU1 genes of bottom-fermenting brewer's yeast. PCR and sequencing confirmed the TDH3 promoter was correctly introduced into the SSU1 regions of the constructed yeasts, and no foreign DNA sequences were found. Using the constructed yeasts, the concentration of sulfite in fermenting wort was higher when compared with the parent strain. In addition, the concentrations of hydrogen sulfide, 3-methyl-2-buten-1-thiol (MBT) and 2-mercapto-3-methyl-1-butanol (2M3MB) were lower when compared with the parent strain. We successfully constructed a self-cloning brewer's yeast with high SSU1 expression that enhanced the sulfite-excreting ability and diminished the production ability of hydrogen sulfide, MBT and 2M3MB. The self-cloning brewer's yeast with high SSU1 expression would contribute to the production of superior quality beer with a high concentration of sulfite and low concentrations of hydrogen sulfide, MBT and 2M3MB. © 2010 The Authors. Journal of Applied Microbiology © 2010 The Society for Applied Microbiology.

  17. Brewer spectrometer total ozone column measurements in Sodankylä

    Science.gov (United States)

    Karppinen, Tomi; Lakkala, Kaisa; Karhu, Juha M.; Heikkinen, Pauli; Kivi, Rigel; Kyrö, Esko

    2016-06-01

    Brewer total ozone column measurements started in Sodankylä in May 1988, 9 months after the signing of The Montreal Protocol. The Brewer instrument has been well maintained and frequently calibrated since then to produce a high-quality ozone time series now spanning more than 25 years. The data have now been uniformly reprocessed between 1988 and 2014. The quality of the data has been assured by automatic data rejection rules as well as by manual checking. Daily mean values calculated from the highest-quality direct sun measurements are available 77 % of time with up to 75 measurements per day on clear days. Zenith sky measurements fill another 14 % of the time series and winter months are sparsely covered by moon measurements. The time series provides information to survey the evolution of Arctic ozone layer and can be used as a reference point for assessing other total ozone column measurement practices.

  18. Temperature dependence of the Brewer global UV measurements

    Science.gov (United States)

    Fountoulakis, Ilias; Redondas, Alberto; Lakkala, Kaisa; Berjon, Alberto; Bais, Alkiviadis F.; Doppler, Lionel; Feister, Uwe; Heikkila, Anu; Karppinen, Tomi; Karhu, Juha M.; Koskela, Tapani; Garane, Katerina; Fragkos, Konstantinos; Savastiouk, Volodya

    2017-11-01

    Spectral measurements of global UV irradiance recorded by Brewer spectrophotometers can be significantly affected by instrument-specific optical and mechanical features. Thus, proper corrections are needed in order to reduce the associated uncertainties to within acceptable levels. The present study aims to contribute to the reduction of uncertainties originating from changes in the Brewer internal temperature, which affect the performance of the optical and electronic parts, and subsequently the response of the instrument. Until now, measurements of the irradiance from various types of lamps at different temperatures have been used to characterize the instruments' temperature dependence. The use of 50 W lamps was found to induce errors in the characterization due to changes in the transmissivity of the Teflon diffuser as it warms up by the heat of the lamp. In contrast, the use of 200 or 1000 W lamps is considered more appropriate because they are positioned at longer distances from the diffuser so that warming is negligible. Temperature gradients inside the instrument can cause mechanical stresses which can affect the instrument's optical characteristics. Therefore, during the temperature-dependence characterization procedure warming or cooling must be slow enough to minimize these effects. In this study, results of the temperature characterization of eight different Brewer spectrophotometers operating in Greece, Finland, Germany and Spain are presented. It was found that the instruments' response changes differently in different temperature regions due to different responses of the diffusers' transmittance. The temperature correction factors derived for the Brewer spectrophotometers operating at Thessaloniki, Greece, and Sodankylä, Finland, were evaluated and were found to remove the temperature dependence of the instruments' sensitivity.

  19. Validation of Brewer and Pandora measurements using OMI total ozone

    Science.gov (United States)

    Baek, Kanghyun; Kim, Jae H.; Herman, Jay R.; Haffner, David P.; Kim, Jhoon

    2017-07-01

    Korea will launch the Geostationary Environment Monitoring Spectrometer (GEMS) instrument in 2018 onboard the Geostationary Korean Multi-Purpose Satellite to monitor tropospheric gas concentrations with high temporal and spatial resolutions. The purpose of this study is to examine the performance of total column ozone (TCO) measurements from ground-based Pandora and Brewer instruments that will be used for validation of the GEMS ozone product. Satellite measurements can be used to detect erroneous outliers at a particular ground station, which deviate significantly from co-located satellite measurements relative to other stations. This is possible because a single satellite retrieval algorithm is used to process the entire satellite dataset, and instrument characteristics typically change slowly over the life of the satellite. Thus, the short-term stability (months) of satellite measurements can be used to estimate the performance of the ground-based measurement network as well as to identify potential problems at individual stations. As a reference for satellite ozone measurements, we have selected TCO data derived from OMI-TOMS V8.5 algorithm, because it is a robust algorithm that has been well studied to identify its various error sources. We validated ground-based Brewer and Pandora TCO measurements using OMI-TOMS TCO data collected over South Korea from March 2012 to December 2014. The Brewer TCO measurements at Pohang showed significant deviation from overall seasonal variation during the study period. In addition, in the presence of clouds, Pandora TCO measurements are unusually ∼7% higher than OMI-TOMS TCO data. To filter out these cloud-contaminated data, we applied a Kalman filter to the Pandora measurements. The diurnal variation in the Kalman-filtered Pandora data agrees well with the Brewer data, and the correlation of Kalman-filtered Pandora data with OMI-TOMS TCO is significantly improved from 0.89 to 0.99 at Seoul and from 0.93 to 0.99 at Busan.

  20. 27 CFR 25.297 - Brewer's Report of Operations, Form 5130.9.

    Science.gov (United States)

    2010-04-01

    ... whether a quarterly report may be filed, the brewer will determine annual production of beer by adding up... in the “Remarks” section of its initial monthly Form 5130.9 that the annual production of beer is not... AND TRADE BUREAU, DEPARTMENT OF THE TREASURY LIQUORS BEER Records and Reports § 25.297 Brewer's Report...

  1. Yeast Genomics for Bread, Beer, Biology, Bucks and Breath

    Science.gov (United States)

    Sakharkar, Kishore R.; Sakharkar, Meena K.

    The rapid advances and scale up of projects in DNA sequencing dur ing the past two decades have produced complete genome sequences of several eukaryotic species. The versatile genetic malleability of the yeast, and the high degree of conservation between its cellular processes and those of human cells have made it a model of choice for pioneering research in molecular and cell biology. The complete sequence of yeast genome has proven to be extremely useful as a reference towards the sequences of human and for providing systems to explore key gene functions. Yeast has been a ‘legendary model’ for new technologies and gaining new biological insights into basic biological sciences and biotechnology. This chapter describes the awesome power of yeast genetics, genomics and proteomics in understanding of biological function. The applications of yeast as a screening tool to the field of drug discovery and development are highlighted and the traditional importance of yeast for bakers and brewers is discussed.

  2. Reproducibility of total ozone column monitoring by the Arosa Brewer spectrophotometer triad

    Science.gov (United States)

    Stübi, R.; Schill, H.; Klausen, J.; Vuilleumier, L.; Ruffieux, D.

    2017-04-01

    The historical review of the total ozone column measurements with the Arosa Brewer triad in operation since 1998 is presented. The calibration history of the different instruments and the data quality control performed at Arosa are described. Over the last 15 years, the Brewer triad shows a dispersion of ˜0.4% between the three collocated instruments and a long-term stability of ±0.5%. These values are a reference metric achievable with well-maintained Brewer instruments under favorable measurement conditions.

  3. Mycobiota and mycotoxins in malted barley and brewer's spent grain from Argentinean breweries

    National Research Council Canada - National Science Library

    Gonzalez Pereyra, M L; Rosa, C A R; Dalcero, A M; Cavaglieri, L R

    2011-01-01

    ... barley types and brands and brewer's grain collected from a major Argentinean brewery. Total fungal counts were performed using the plate count method. Aflatoxin B(1), AFB(2), AFG(1), AFG(2) and Zearalenone (ZEA...

  4. Lyman A. Brewer III (1907-1988): surgeon-scientist, inspirational teacher, and humanist.

    Science.gov (United States)

    Carter, R

    1998-12-01

    Dr. Lyman Augustus Brewer III, a distinguished, colorful thoracic surgeon and among the first to practice that specialty in the West, died on June 25, 1988, in Los Angeles, California, after a courageous battle with lymphoma. Dr. Brewer was a great humanist, innovative clinical surgeon, charismatic teacher, and surgical leader. In World War II, Lieutenant Colonel Brewer served in the Second Auxiliary Surgical Group in the Mediterranean and European theaters and helped define criteria that became the standard for the management of thoracic war injuries. Out of this experience he authored the classic paper, "The Wet Lung in War Casualties." Dr. Brewer's scientific contributions embraced the broad spectrum of thoracic surgical topics, including treatment of tuberculosis, classification of lung cancer, bronchial stump buttressing using the pericardial fat pad (Brewer fat pad), and management of esophageal perforation. Dr Brewer wrote seven books and more than 100 papers, and served as First Vice President of The American College of Surgeons and as President of the American Association for Thoracic Surgery, The Society of Thoracic Surgeons, and The Pacific Coast Surgical Association.

  5. Extraction of brewer's yeasts using different methods of cell disruption for practical biodiesel production

    Czech Academy of Sciences Publication Activity Database

    Řezanka, Tomáš; Matoulková, D.; Kolouchová, I.; Masák, J.; Víden, I.; Sigler, Karel

    2015-01-01

    Roč. 60, č. 3 (2015), s. 225-234 ISSN 0015-5632 R&D Projects: GA ČR(CZ) GAP503/11/0215 Institutional support: RVO:61388971 Keywords : CHAIN FATTY-ACIDS * WATER -BASED MEDIA * STREPTOMYCES-FRADIAE Subject RIV: EE - Microbiology, Virology Impact factor: 1.335, year: 2015

  6. Ozone, spectral irradiance and aerosol measurements with the Brewer spectro radiometer; Misure di ozono, irradianza spettrale ultravioletta e aerosol con lo spettroradiometro Brewer

    Energy Technology Data Exchange (ETDEWEB)

    Marenco, F.; Di Sarra, A. [ENEA, Centro Ricerche Casaccia, Rome (Italy)

    2001-07-01

    In this technical report a detailed description of the Brewer spectro radiometer, a widespread instrument for ozone and ultraviolet radiation, is given. The methodologies used to measure these quantities and for instrument calibration are described in detail. Finally a new methodology, developed by ENEA to derive the aerosol optical depth from the Brewer routine total ozone measurements, is described. This methodology is based on Langley extrapolation, on the determination of the transmissivity of the Brewer neutral density filters, and on a statistically significant number of half days of measurements obtained in could-free conditions. Results of this method, obtained with the Brewer of the ENEA station for climate observations Roberto Sarao, located in the island of Lampedusa, are reported. These results confirm the validity of the method, thanks to independent measurements taken in 1999 with a Multi filter Rotating Shadow band Radiometer. This methodology allows researchers to obtain an aerosol climatology from ozone measurements obtained at several sites world-wide. [Italian] In questo rapporto tecnico viene fornita la descrizione dettagliata di uno strumento comunemente utilizzato per le misure di ozono e radiazione ultravioletta: lo spettroradiometro Brewer. Le metodologie usate per la misura di queste grandezze e per la calibrazione dello strumento vengono descritte in dettaglio. Infine, viene descritto una nuova metodologia, messa a punto dall'ENEA, per ricavare lo spessore ottico degli aerosol a partire dalle misure di ozono fatte normalmente dal Brewer. Questa metodologia si basa su di una calibrazione effettuata con il metodo dell' estrapolazione di Langley, sulla misura della trasmissivita' dei filtri a densita' neutra dello strumento, e su un numero statisticamente grande di mezze giornate di misure effettuate in assenza di nuvole. Sono riportati alcuni risultati della metodologia, ottenuti con il Brewer della Stazione per le

  7. How did Saccharomyces evolve to become a good brewer?

    Science.gov (United States)

    Piskur, Jure; Rozpedowska, Elzbieta; Polakova, Silvia; Merico, Annamaria; Compagno, Concetta

    2006-04-01

    Brewing and wine production are among the oldest technologies and their products are almost indispensable in our lives. The central biological agents of beer and wine fermentation are yeasts belonging to the genus Saccharomyces, which can accumulate ethanol. Recent advances in comparative genomics and bioinformatics have made it possible to elucidate when and why yeasts produce ethanol in high concentrations, and how this remarkable trait originated and developed during their evolutionary history. Two research groups have shed light on the origin of the genes encoding alcohol dehydrogenase and the process of ethanol accumulation in Saccharomyces cerevisiae.

  8. LIVE/DEAD YEAST VIABILITY STAINING AS A TOOL FOR IMPROVING ARTISANAL PILSNER BEER PRODUCTION

    Directory of Open Access Journals (Sweden)

    Benedetta Bottari

    2014-10-01

    Full Text Available The production of an artisanal beer, made by brewers using traditional practices on a small scale, is founded on the empirical adjustment of parameters, including yeasts handling and serial repitching. The aim of this study was to monitor yeast viability during different stages of artisanal beer productions through the Live/Dead Yeast viability staining and to correlate it with fermentation dynamics in order to increase process standardization and to maintain the quality of final products. Yeast viability and fermentation activities were evaluated during seven fermentation cycles of an artisanal pilsner beer. Yeast inoculated with higher viability performed generally better in fermentation, resulting in faster sugar consumption, faster ethanol production and stability. Handling yeast and serial repitching based on Live/Dead viability measurements, could be the key way to ensure reliable manufacture of high quality beer and to improve process standardization particularly for microbreweries, where variability of production can be a challenging point.

  9. Intercomparison of Aerosol Optical Depth from Brewer Ozone spectrophotometers and CIMEL sunphotometers measurements

    Directory of Open Access Journals (Sweden)

    A. Cheymol

    2009-01-01

    Full Text Available The Langley plot method applied on the Brewer Ozone measurements can provide accurate Aerosol Optical Depth (AOD in the UV-B. We present seven intercomparisons between AOD retrieved from Brewer Ozone measurements at 320 nm and AOD measured by CIMEL sunphotometer at 340 nm or 440 nm (shifted to 320 nm in using the Angström's law, which are stored in the international AERONET database. Only the intercomparisons between co-located instruments can be used to validate the Langley Plot Method applied to the Brewer measurements: in this case, all the correlation coefficients are above 0.82. If the instruments are not at the same site, the correlation between the AOD retrieved by both instruments is much lower. In applying the Angström's law the intercomparison is improved compared to previous study.

  10. The Effect of Feeding Sorghum-Barley Brewer's Spent Grain (Sbbsg ...

    African Journals Online (AJOL)

    The objective of the study was to establish if inclusion of Sorghum-Barley Brewer's Spent Grain (SBBSG) in laying hen diets will affect laying performance and egg quality. A total of 300 Bovan Brown laying hens (37 weeks old) were randomly allocated in a completely randomized design, to five dietary treatments, T1, T2, T3, ...

  11. An "Alms-Basket" of "Bric-a-Brac": "Brewer's Dictionary of Phrase and Fable".

    Science.gov (United States)

    Bunge, Charles A.

    1999-01-01

    Describes the development and history of "Brewer's Dictionary of Phrase and Fable," a reference source first published in 1870 that includes the etymology of phrases, allusions and words. Discusses reviews that reflected and shaped its status as a standard reference book, describes the current edition, and considers its enduring value.…

  12. Effects of process parameters on the properties of barley containing snacks enriched with brewer's spent grain

    National Research Council Canada - National Science Library

    Kirjoranta, Satu; Tenkanen, Maija; Jouppila, Kirsi

    2016-01-01

    Brewer's spent grain (BSG), a by-product of malting of barley in the production of malt extract, was used as an ingredient in extruded barley-based snacks in order to improve the nutritional value of the snacks and widen...

  13. 27 CFR 28.226 - Removals of beer by agent on behalf of brewer.

    Science.gov (United States)

    2010-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 1 2010-04-01 2010-04-01 false Removals of beer by agent... TAX AND TRADE BUREAU, DEPARTMENT OF THE TREASURY LIQUORS EXPORTATION OF ALCOHOL Exportation of Beer With Benefit of Drawback Execution of Claims § 28.226 Removals of beer by agent on behalf of brewer...

  14. 27 CFR 25.152 - Reduced rate of tax for certain brewers.

    Science.gov (United States)

    2010-04-01

    ..., grandchildren, parents, and grandparents. (2) Production of beer. The production of beer as recorded in the... determining compliance with the 2,000,000 barrel limitation, production of beer by a brewer or a controlled... than one brewery shall include the combined production of beer at all their breweries when determining...

  15. Charles L. Brewer Award for Distinguished Teaching of Psychology: Neil Lutsky

    Science.gov (United States)

    American Psychologist, 2011

    2011-01-01

    The American Psychological Foundation (APF) Charles L. Brewer Award for Distinguished Teaching of Psychology recognizes an outstanding career contribution to the teaching of psychology. The 2011 recipient of the Distinguished Teaching Award is Neil Lutsky. Dorothy W. Cantor, president of the APF, will present the APF Distinguished Teaching Award…

  16. Effect of Sorghum -Barley Brewer's Spent Grain as a Feed Ingredient ...

    African Journals Online (AJOL)

    The objective of the study was to determine if the inclusion of Sorghum-Barley Brewer's Spent Grain (SBBSG) in broiler diets will affect growth performance and carcass characteristics. A total of 380 Ross broiler chicks were brooded on a common diet without SBBSG for 28 days after which they were randomly assigned to ...

  17. The Evaluation of Total Column Ozone Measurements from Pandora relatvie to Brewer and OMI

    Science.gov (United States)

    Baek, K. H.; Kim, J. H.; Herman, J. R.; Haffner, D. P.

    2014-12-01

    Korea has a plan to launch the Geostationary Environment Monitoring Spectrometer (GEMS) into geostationary orbit in 2018 to monitor tropospheric air pollutant on hourly basis over East Asia. Because ground based measurements are required to validate ozone products from GEMS, we consider to use PANDORA instrument based on the DOAS method, which can provide hourly total column ozone (TCO) measurements even in the presence of aerosols and clouds. This study is to examine the performance of TCO from PANDORA, which was installed in Busan and Seoul, by comparing with TCO from Brewer, Dobson, and OMI from March 2012 to December 2013. PANDORA TCO showed a high correlation of 0.99 with a negative bias of 2-3% relative to Brewer and Dobson TCO. However, the correlation between PANDORA and OMI TCO was lower than that between Brewer and OMI TCO. We found that Brewer didn't provide TCO in the presence of clouds. However, even though PANDORA measurements were filtered out during thick cloudy condition, the PANDORA still showed unusual high ozone during thin cloudy condition. In order to have continuous PANDORA measurements for comparison with hourly GEMS measurements, the PANDORA measurements under thin cloudy condition are required to be corrected. We have performed the correction of PANDORA observations using Kalman filter which is a set of mathematical equations that provides an efficient computational solution of the least-squares method. When we applied this approach, the result showed the improvement in correlation between PANDORA and OMI TCO as much as that between Brewer and OMI TCO.

  18. Comparison between Brewer spectrometer, M 124 filter ozonometer and Dobson spectrophotometer

    Science.gov (United States)

    Feister, U.

    1994-01-01

    Concurrent measurements were taken using the Brewer spectrometer no. 30, the filter ozonometer M 124 no. 200 and the Dobson spectrophotometer no. 71 from September 1987 to December 1988 at Potsdam. The performance of the instrument types and the compatibility of ozone data was checked under the conditions of a field measuring station. Total ozone values derived from Dobson AD direct sun measurements were considered as standard. The Dobson instrument had been calibrated at intercomparisons with the World Standard Dobson instrument no. 83 (Boulder) and with the Regional Standard instrument no. 64 (Potsdam), while the Brewer instrument was calibrated several times with the Travelling Standard Brewer no. 17 (Canada). The differences between individual Brewer DS (direct sun) ozone data and Dobson ADDS are within plus or minus 3 percent with half of all differences within plus or minus 1 percent. Less than 0.7 percent of the systematic difference can be due to atmospheric SO2. Due to inadequate regression coefficients Brewer ZB (zenith blue) ozone measurements are by (3...4) percent higher than Dobson ADDS ozone values. M124 DS ozone data are systematically by (1...2) percent higher than Dobson ADDS ozone with 50 percent of the differences within plus or minus 4 percent, but with extreme differences up to plus or minus (20...25) percent. M124 ZB ozone values are by (3...5) percent higher than Dobson ADDS with all the differences within plus or minus 10 percent, i.e. the scatter of differences is smaller for ZB than for M 124 DS measurements, Results for differences in the daily mean ozone values are also addressed. The differences include the uncertainties in the ozone values derived from both types of measurements. They provide an indication of the uncertainty in ozone data and the comparability of ozone values derived from different types of instruments.

  19. Intercomparison of total column ozone data from the Pandora spectrophotometer with Dobson, Brewer, and OMI measurements over Seoul, Korea

    Directory of Open Access Journals (Sweden)

    J. Kim

    2017-10-01

    Full Text Available Daily total column ozone (TCO measured using the Pandora spectrophotometer (no. 19 was compared with data from the Dobson (no. 124 and Brewer (no. 148 spectrophotometers, as well as from the Ozone Monitoring Instrument (OMI (with two different algorithms, Total Ozone Mapping Spectrometer (TOMS TOMS and differential optical absorption spectroscopy (DOAS methods, over the 2-year period between March 2012 and March 2014 at Yonsei University, Seoul, Korea. Based on the linear-regression method, the TCO from Pandora is closely correlated with those from other instruments with regression coefficients (slopes of 0.95 (Dobson, 1.00 (Brewer, 0.98 (OMI-TOMS, and 0.97 (OMI-DOAS, and determination coefficients (R2 of 0.95 (Dobson, 0.97 (Brewer, 0.96 (OMI-TOMS, and 0.95 (OMI-DOAS. The daily averaged TCO from Pandora has within 3 % differences compared to TCO values from other instruments. For the Dobson measurements in particular, the difference caused by the inconsistency in observation times when compared with the Pandora measurements was up to 12.5 % because of diurnal variations in the TCO values. However, the comparison with Brewer after matching the observation time shows agreement with large R2 and small biases. The TCO ratio between Brewer and Pandora shows the 0.98 ± 0.03, and the distributions for relative differences between two instruments are 89.2 and 57.1 % of the total data within the error ranges of 3 and 5 %, respectively. The TCO ratio between Brewer and Pandora also is partially dependent on solar zenith angle. The error dependence by the observation geometry is essential to the further analysis focusing on the sensitivity of aerosol and the stray-light effect in the instruments.

  20. Intercomparison of total column ozone data from the Pandora spectrophotometer with Dobson, Brewer, and OMI measurements over Seoul, Korea

    Science.gov (United States)

    Kim, Jiyoung; Kim, Jhoon; Cho, Hi-Ku; Herman, Jay; Park, Sang Seo; Lim, Hyun Kwang; Kim, Jae-Hwan; Miyagawa, Koji; Lee, Yun Gon

    2017-10-01

    Daily total column ozone (TCO) measured using the Pandora spectrophotometer (no. 19) was compared with data from the Dobson (no. 124) and Brewer (no. 148) spectrophotometers, as well as from the Ozone Monitoring Instrument (OMI) (with two different algorithms, Total Ozone Mapping Spectrometer (TOMS) TOMS and differential optical absorption spectroscopy (DOAS) methods), over the 2-year period between March 2012 and March 2014 at Yonsei University, Seoul, Korea. Based on the linear-regression method, the TCO from Pandora is closely correlated with those from other instruments with regression coefficients (slopes) of 0.95 (Dobson), 1.00 (Brewer), 0.98 (OMI-TOMS), and 0.97 (OMI-DOAS), and determination coefficients (R2) of 0.95 (Dobson), 0.97 (Brewer), 0.96 (OMI-TOMS), and 0.95 (OMI-DOAS). The daily averaged TCO from Pandora has within 3 % differences compared to TCO values from other instruments. For the Dobson measurements in particular, the difference caused by the inconsistency in observation times when compared with the Pandora measurements was up to 12.5 % because of diurnal variations in the TCO values. However, the comparison with Brewer after matching the observation time shows agreement with large R2 and small biases. The TCO ratio between Brewer and Pandora shows the 0.98 ± 0.03, and the distributions for relative differences between two instruments are 89.2 and 57.1 % of the total data within the error ranges of 3 and 5 %, respectively. The TCO ratio between Brewer and Pandora also is partially dependent on solar zenith angle. The error dependence by the observation geometry is essential to the further analysis focusing on the sensitivity of aerosol and the stray-light effect in the instruments.

  1. Physiological characterization of brewer's yeast in high-gravity beer fermentations with glucose or maltose syrups as adjuncts

    DEFF Research Database (Denmark)

    Piddocke, Maya Petrova; kreisz, Stefan; Heldt-Hansen, Hans Peter

    2009-01-01

    resulted in a lower specific growth rate, a longer lag phase before initiation of ethanol production, incomplete sugar utilization, and an increase in the concentrations of ethyl acetate and isoamyl acetate in the final beer. Increasing the gravity by adding maltose syrup as opposed to glucose syrup...

  2. Production, Purification, and Characterization of a Major Penicillium glabrum Xylanase Using Brewer's Spent Grain as Substrate

    Directory of Open Access Journals (Sweden)

    Adriana Knob

    2013-01-01

    Full Text Available In recent decades, xylanases have been used in many processing industries. This study describes the xylanase production by Penicillium glabrum using brewer's spent grain as substrate. Additionally, this is the first work that reports the purification and characterization of a xylanase using this agroindustrial waste. Optimal production was obtained when P. glabrum was grown in liquid medium in pH 5.5, at 25 °C, under stationary condition for six days. The xylanase from P. glabrum was purified to homogeneity by a rapid and inexpensive procedure, using ammonium sulfate fractionation and molecular exclusion chromatography. SDS-PAGE analysis revealed one band with estimated molecular mass of 18.36 kDa. The optimum activity was observed at 60 °C, in pH 3.0. The enzyme was very stable at 50 °C, and high pH stability was verified from pH 2.5 to 5.0. The ion Mn2+ and the reducing agents β-mercaptoethanol and DTT enhanced xylanase activity, while the ions Hg2+, Zn2+, and Cu2+ as well as the detergent SDS were strong inhibitors of the enzyme. The use of brewer's spent grain as substrate for xylanase production cannot only add value and decrease the amount of this waste but also reduce the xylanase production cost.

  3. Matrix-assisted laser desorption/ionisation mass spectrometry of transfer ribonucleic acids isolated from yeast.

    Science.gov (United States)

    Gruic-Sovulj, I; Lüdemann, H C; Hillenkamp, F; Weygand-Durasevic, I; Kucan, Z; Peter-Katalinic, J

    1997-01-01

    tRNATyr and tRNASer purified from bulk brewer's yeast tRNA were subjected to analysis by matrix-assisted laser desorption/ionisation time-of-flight mass spectrometry. Choosing a mixture of 2,4,6- and 2,3,4-trihydroxy-acetophenone and diammonium citrate as matrix a mass resolution of up to 220 (FWHM) was achieved in the linear mode of operation. Cation adduct suppression by addition of cation exchange beads and a chelating agent (CDTA) is shown to substantially improve mass resolution for this class of molecules. PMID:9108172

  4. Vaginal Yeast Infections

    Science.gov (United States)

    ... Yeast Infections Print A A A en español Infecciones vaginales por hongos What Are Vaginal Yeast Infections? ... keep the amount in a person's body under control. But yeast in the vagina can sometimes "overgrow" ...

  5. Yeast Infection (Vaginal)

    Science.gov (United States)

    ... vaginal discharge with a cottage cheese appearance Complicated yeast infection You might have a complicated yeast infection ... have an uncomplicated or a complicated infection. Uncomplicated yeast infection For mild to moderate symptoms and infrequent ...

  6. 27 CFR 25.160 - Tax adjustment for brewers who produce more than 2,000,000 barrels of beer.

    Science.gov (United States)

    2010-04-01

    ... who produce more than 2,000,000 barrels of beer. 25.160 Section 25.160 Alcohol, Tobacco Products and Firearms ALCOHOL AND TOBACCO TAX AND TRADE BUREAU, DEPARTMENT OF THE TREASURY LIQUORS BEER Tax on Beer Determination of Tax § 25.160 Tax adjustment for brewers who produce more than 2,000,000 barrels of beer. Each...

  7. Genetic diversity, genetic structure, and mating system of brewer spruce (Pinaceae), a relict of the acto-tertiary forest

    Science.gov (United States)

    F. Thomas Ledig; Paul D. Hodgskiss; David R. Johnson

    2005-01-01

    Brewer spruce (Picea breweriana), a relict of the widespread Arcto-Tertiary forests, is now restricted to a highly fragmented range in the Klamath Region of California and Oregon. Expected heterozygosity for 26 isozyme loci, averaged over 10 populations, was 0.121. More notable than the relatively high level of diversity when compared to other woody...

  8. Dead time effect on the Brewer measurements: correction and estimated uncertainties

    Science.gov (United States)

    Fountoulakis, Ilias; Redondas, Alberto; Bais, Alkiviadis F.; José Rodriguez-Franco, Juan; Fragkos, Konstantinos; Cede, Alexander

    2016-04-01

    Brewer spectrophotometers are widely used instruments which perform spectral measurements of the direct, the scattered and the global solar UV irradiance. By processing these measurements a variety of secondary products can be derived such as the total columns of ozone (TOC), sulfur dioxide and nitrogen dioxide and aerosol optical properties. Estimating and limiting the uncertainties of the final products is of critical importance. High-quality data have a lot of applications and can provide accurate estimations of trends.The dead time is specific for each instrument and improper correction of the raw data for its effect may lead to important errors in the final products. The dead time value may change with time and, with the currently used methodology, it cannot always be determined accurately. For specific cases, such as for low ozone slant columns and high intensities of the direct solar irradiance, the error in the retrieved TOC, due to a 10 ns change in the dead time from its value in use, is found to be up to 5 %. The error in the calculation of UV irradiance can be as high as 12 % near the maximum operational limit of light intensities. While in the existing documentation it is indicated that the dead time effects are important when the error in the used value is greater than 2 ns, we found that for single-monochromator Brewers a 2 ns error in the dead time may lead to errors above the limit of 1 % in the calculation of TOC; thus the tolerance limit should be lowered. A new routine for the determination of the dead time from direct solar irradiance measurements has been created and tested and a validation of the operational algorithm has been performed. Additionally, new methods for the estimation and the validation of the dead time have been developed and are analytically described. Therefore, the present study, in addition to highlighting the importance of the dead time for the processing of Brewer data sets, also provides useful information for their

  9. On the compatibility of Brewer total column ozone measurements in two adjacent valleys (Arosa and Davos) in the Swiss Alps

    Science.gov (United States)

    Stübi, René; Schill, Herbert; Klausen, Jörg; Vuilleumier, Laurent; Gröbner, Julian; Egli, Luca; Ruffieux, Dominique

    2017-11-01

    The Arosa site is well known in the ozone community for its continuous total ozone column observations that have been recorded since 1926. Originally based on Dobson sun spectrophotometers, the site has been gradually complemented by three automatic Brewer instruments, in operation since 1998. To secure the long-term ozone monitoring in this Alpine region and to benefit from synergies with the World Radiation Center, the feasibility of moving this activity to the nearby site at Davos (aerial distance of 13 km) has been explored. Concerns about a possible rupture of the 90-year-long record has motivated a careful comparison of the two sites, since great attention to the data continuity and quality has always been central to the operations of the observatory at Arosa. To this end, one element of the Arosa Brewer triad has been set up at the Davos site since November 2011 to realize a campaign of parallel measurements and to study the deviations between the three Brewer instruments. The analysis of the coincident measurement shows that the differences between Arosa and Davos remain within the range of the long-term stability of the Brewer instruments. A nonsignificant seasonal cycle is observed, which could possibly be induced by a stray-light bias and the altitude difference between the two sites. These differences are shown to be lower than the short-term variability of the time series and the overall uncertainty from individual Brewer instruments and therefore are not statistically significant. It is therefore concluded that the world's longest time series of the total ozone column obtained at Arosa site could be safely extended and continued with measurements taken from instruments located at the nearby Davos site without introducing a bias to this unique record.

  10. Brewer's Grain from Cameroon Brewery in Breeder Chicken Rations : Effect on Productive and Reproductive Performance

    Directory of Open Access Journals (Sweden)

    Mafeni, MJ.

    2001-01-01

    Full Text Available In order to evaluate the effect of brewer's dried grain (BDG on the productive and reproductive traits in breeder chickens, 120 laying hens and 12 cocks of ISA commercial breed were subjected to dietary treatments containing 0, 10, 20, and 30 % levels of BDG. Feed and water were provided ad libitum over the 5-months experimental period. Reproductive and productive traits such as egg production, egg weight, albumen height, shell weight, semen quantity fertility and hatchability of fertile eggs were measured. Results indicated that when BDG was fed at the 30 % level in the ration, the hen-day egg production (50.6 % was significantly (P of inclusion. There was a significant (P 0.05 was noticed between treatments for ratio of shell weight to egg weight, albumen height, semen quantity and fertility. The results suggest that although the 30 % level of BDG can be tolerated, the 20 %, level of BDG inclusion is more appropriate for breeder birds.

  11. Charles L. Brewer Award for Distinguished Teaching of Psychology: Sue Frantz.

    Science.gov (United States)

    2016-01-01

    The American Psychological Foundation (APF) Charles L. Brewer Distinguished Teaching of Psychology Award recognizes an outstanding career contribution to the teaching of psychology. The 2016 recipient of the Distinguished Teaching Award is Sue Frantz. Dorothy W. Cantor, president of the APF, will present the Distinguished Teaching Award at the 124th Annual Convention of the American Psychological Association on August 5, 2016, at 4:00 p.m. Members of the 2016 APF Board of Trustees are Dorothy W. Cantor, president; David H. Barlow, vice president; Melba J. T. Vasquez, secretary; Richard C. McCarty, treasurer; Elisabeth R. Straus, executive vice president/executive director; Cynthia Belar; Camilla Benbow; Rosie Phillips Bingham; Connie S. Chan; Anthony Jackson; Terence M. Keane; Archie L. Turner; W. Bruce Walsh; and Bonnie Markham and Rick McGraw, APA Board of Directors liaisons. (PsycINFO Database Record (c) 2016 APA, all rights reserved).

  12. Prions in yeast

    OpenAIRE

    Bezdíčka, Martin

    2013-01-01

    The thesis describes yeast prions and their biological effects on yeast in general. It defines the basic characteristics of yeast prions, that distinguish prions from other proteins. The thesis introduces various possibilities of prion formation, and propagation as well as specific types of yeast prions, including various functions of most studied types of prions. The thesis also focuses on chaperones that affect the state of yeast prions in cells. Lastly, the thesis indicates similarities be...

  13. Effect of on Rumen Fermentation Characteristics of Dried Brewers Grain, Methane Production and Bacterial Diversity

    Directory of Open Access Journals (Sweden)

    Alvin P. Soriano

    2014-11-01

    Full Text Available The effects of Lactobacillus mucosae (L. mucosae, a potential direct fed microbial previously isolated from the rumen of Korean native goat, on the rumen fermentation profile of brewers grain were evaluated. Fermentation was conducted in serum bottles each containing 1% dry matter (DM of the test substrate and either no L. mucosae (control, 1% 24 h broth culture of L. mucosae (T1, or 1% inoculation with the cell-free culture supernatant (T2. Each serum bottle was filled anaerobically with 100 mL of buffered rumen fluid and sealed prior to incubation for 0, 6, 12, 24, and 48 h from which fermentation parameters were monitored and the microbial diversity was evaluated. The results revealed that T1 had higher total gas production (65.00 mL than the control (61.33 mL and T2 (62.00 mL (p<0.05 at 48 h. Consequently, T1 had significantly lower pH values (p<0.05 than the other groups at 48 h. Ammonia nitrogen (NH3-N, individual and total volatile fatty acids (VFA concentration and acetate:propionate ratio were higher in T1 and T2 than the control, but T1 and T2 were comparable for these parameters. Total methane (CH4 production and carbon dioxide (CO2 were highest in T1. The percent DM and organic matter digestibilities were comparable between all groups at all times of incubation. The total bacterial population was significantly higher in T1 (p<0.05 at 24 h, but then decreased to levels comparable to the control and T2 at 48 h. The denaturing gradient gel electrophoresis profile of the total bacterial 16s rRNA showed higher similarity between T1 and T2 at 24 h and between the control and T1 at 48 h. Overall, these results suggest that addition of L. mucosae and cell-free supernatant during the in vitro fermentation of dried brewers grain increases the VFA production, but has no effect on digestibility. The addition of L. mucosae can also increase the total bacterial population, but has no significant effect on the total microbial diversity. However

  14. Bioavailability of selenium from fish, yeast and selenate: a comparative study in humans using stable isotopes.

    Science.gov (United States)

    Fox, T E; Van den Heuvel, E G H M; Atherton, C A; Dainty, J R; Lewis, D J; Langford, N J; Crews, H M; Luten, J B; Lorentzen, M; Sieling, F W; van Aken-Schneyder, P; Hoek, M; Kotterman, M J J; van Dael, P; Fairweather-Tait, S J

    2004-02-01

    To measure the bioavailability of selenium from cooked and raw fish in humans by estimating and comparing apparent absorption and retention of selenium in biosynthetically labelled fish with labelled selenate and biosynthetically labelled selenium in brewers yeast. The intervention study was a parallel, randomised, reference substance controlled design carried out at two different centres in Europe. The human study was carried out at the Institute of Food Research, Norwich, UK and at TNO Nutrition and Food Research, Zeist, The Netherlands. In all, 35 male volunteers aged 18-50 y were recruited; 17 subjects were studied in Norwich (UK) and 18 in Zeist (Netherlands). All of the recruited subjects completed the study. Biosynthetically labelled trout fish (processed by two different methods), biosynthetically labelled brewers yeast and isotopically labelled selenate were used to estimate selenium apparent absorption and retention by quantitative analysis of stable isotope labels recovered in faeces and urine. Subjects consumed the labelled foods in four meals over two consecutive days and absorption was measured by the luminal disappearance method over 10 days. Urinary clearance of isotopic labels was measured over 7 days to enable retention to be calculated. Apparent absorption of selenium from fish was similar to selenate and there was no difference between the two processing methods used. However, retention of fish selenium was significantly higher than selenate (P<0.001). Apparent absorption and retention of yeast selenium was significantly different (P<0.001) from both fish selenium and selenate. Fish selenium is a highly bioavailable source of dietary selenium. Cooking did not affect selenium apparent absorption or retention from fish. Selenium from yeast is less bioavailable.

  15. Techno-economic analysis for brewer's spent grains use on a biorefinery concept: the Brazilian case.

    Science.gov (United States)

    Mussatto, Solange I; Moncada, Jonathan; Roberto, Inês C; Cardona, Carlos A

    2013-11-01

    A techno-economic analysis for use of brewer's spent grains (BSG) on a biorefinery concept for the Brazilian case is presented. Four scenarios based on different levels of heat and mass integration for the production of xylitol, lactic acid, activated carbon and phenolic acids are shown. A simulation procedure using the software Aspen Plus and experimental yields was used. Such procedure served as basis for the techno-economic and environmental assessment according to the Brazilian conditions. Full mass integration on water and full energy integration was the configuration with the best economic and environmental performance. For this case, the obtained economic margin was 62.25%, the potential environmental impact was 0.012 PEI/kg products, and the carbon footprint of the processing stage represented 0.96 kg CO2-e/kg of BSG. This result served as basis to draw recommendations on the technological, economic and environmental feasibility for implementation of such type of biorefinery in Brazil. Copyright © 2013 Elsevier Ltd. All rights reserved.

  16. Efficient conversion of pretreated brewer's spent grain and wheat bran by submerged cultivation of Hericium erinaceus.

    Science.gov (United States)

    Wolters, Niklas; Schabronath, Christoph; Schembecker, Gerhard; Merz, Juliane

    2016-12-01

    Brewer's spent grain (BSG) and wheat bran (WB) are industrial byproducts that accumulate in millions of tons per year and are typically applied as animal feed. Since both byproducts show a great potential as substrates for fermentation, the approach developed in this study consists of utilizing these lignocellulosic byproducts for biomass production of the medicinal fungus Hericium erinaceus through submerged cultivation. To increase the biological efficiency of the bioconversion, acidic pretreatment was applied yielding a bioconversion of 38.6% for pretreated BSG and 34.8% for pretreated WB. This study shows that the complete degradation of (hemi)cellulose into monosaccharides was not required for an efficient bioconversion. The produced fungal biomass was applied in a second fermentation step to induce the secondary metabolite erinacine C production. Thus, biomass was produced as a functional food ingredient with erinacine C contents of 174.8mg/g for BSG and 99.3mg/g for WB based bioconversions. Copyright © 2016 Elsevier Ltd. All rights reserved.

  17. Improved retrieval of nitrogen dioxide (NO2) column densities by means of MKIV Brewer spectrophotometers

    Science.gov (United States)

    Diémoz, H.; Siani, A. M.; Redondas, A.; Savastiouk, V.; McElroy, C. T.; Navarro-Comas, M.; Hase, F.

    2014-11-01

    A new algorithm to retrieve nitrogen dioxide (NO2) column densities using MKIV ("Mark IV") Brewer spectrophotometers is described. The method includes several improvements, such as a more recent spectroscopic data set, the reduction of measurement noise, interference by other atmospheric species and instrumental settings, and a better determination of the zenith sky air mass factor. The technique was tested during an ad hoc calibration campaign at the high-altitude site of Izaña (Tenerife, Spain) and the results of the direct sun and zenith sky geometries were compared to those obtained by two reference instruments from the Network for the Detection of Atmospheric Composition Change (NDACC): a Fourier Transform Infrared Radiometer (FTIR) and an advanced visible spectrograph (RASAS-II) based on the differential optical absorption spectrometry (DOAS) technique. To determine the extraterrestrial constant, an easily implementable extension of the standard Langley technique for very clean sites without tropospheric NO2 was developed which takes into account the daytime linear drift of stratospheric nitrogen dioxide due to photochemistry. The measurement uncertainty was thoroughly determined by using a Monte Carlo technique. Poisson noise and wavelength misalignments were found to be the most influential contributors to the overall uncertainty, and possible solutions are proposed for future improvements. The new algorithm is backward-compatible, thus allowing for the reprocessing of historical data sets.

  18. Dried brewers grains in growing rabbits: nutritional value and effects on performance

    Directory of Open Access Journals (Sweden)

    P.J.D.O. Lima

    2017-09-01

    Full Text Available Two assays were carried out to determine i the nutritional value of dried brewers’ grains and ii the effects of inclusion of this ingredient in growing rabbit diets on animal performance and economic performance of the breeding unit. In the digestibility assay, a total of 28 male rabbits were distributed in 2 groups differing in the diet offered to animals: a reference diet (35.51% neutral detergent fibre and 16.50% crude protein [CP] and a test diet (60% of reference diet and 40% of dried brewers grains. The dried brewers’ grain contained 37.9% of CP and 3371 kcal digestible energy/kg dry matter. In the performance study, 80 weaned rabbits (40 males and 40 females were allotted at 40 d of age to 5 groups differing in the inclusion levels of dried brewers’ grains (0, 7, 14, 21 and 28% from 40 d to 90 d of age. Inclusion of dried brewers’ grains did not affect the live weight at 90 d, the feed intake between 40 d and 90 d or the dressing percentage of rabbits (on average 223 g, 96 g/d and 51.3%, respectively. There was no effect of diet on the meat quality parameters (69.5% water holding capacity, 25.6% cooking loss, 3.4 kg/cm2 Warner-Bratzler shear force and pH 5.70 and inclusion levels above 14% reduced the feed cost (–18%; P

  19. Enhancement of biohydrogen production from brewers' spent grain by calcined-red mud pretreatment.

    Science.gov (United States)

    Zhang, Jishi; Zang, Lihua

    2016-06-01

    This paper investigated the utilization of calcined-red mud (CRM) pretreatment to enhance fermentative hydrogen yields from brewers' spent grain (BSG). The BSG samples were treated with different concentrations (0.0-20g/L) of CRM at 55°C for 48h, before the biohydrogen process with heat-treated anaerobic sludge inoculum. The highest specific hydrogen production of 198.62ml/g-VS was obtained from the BSG treated with 10g/L CRM, with the corresponding lag time of 10.60h. Hydrogen yield increments increased by 67.74%, compared to the control tests without CRM. The results demonstrated that the CRM could hydrolyze more cellulose and further provided adequate broth and suitable pH value for efficient fermentative hydrogen. The model-based analysis showed that the modified Gompertz model presented a better fit for the experimental data than the first-order model. Copyright © 2016 Elsevier Ltd. All rights reserved.

  20. Improved retrieval of nitrogen dioxide (NO2 column densities by means of MKIV Brewer spectrophotometers

    Directory of Open Access Journals (Sweden)

    H. Diémoz

    2014-11-01

    Full Text Available A new algorithm to retrieve nitrogen dioxide (NO2 column densities using MKIV ("Mark IV" Brewer spectrophotometers is described. The method includes several improvements, such as a more recent spectroscopic data set, the reduction of measurement noise, interference by other atmospheric species and instrumental settings, and a better determination of the zenith sky air mass factor. The technique was tested during an ad hoc calibration campaign at the high-altitude site of Izaña (Tenerife, Spain and the results of the direct sun and zenith sky geometries were compared to those obtained by two reference instruments from the Network for the Detection of Atmospheric Composition Change (NDACC: a Fourier Transform Infrared Radiometer (FTIR and an advanced visible spectrograph (RASAS-II based on the differential optical absorption spectrometry (DOAS technique. To determine the extraterrestrial constant, an easily implementable extension of the standard Langley technique for very clean sites without tropospheric NO2 was developed which takes into account the daytime linear drift of stratospheric nitrogen dioxide due to photochemistry. The measurement uncertainty was thoroughly determined by using a Monte Carlo technique. Poisson noise and wavelength misalignments were found to be the most influential contributors to the overall uncertainty, and possible solutions are proposed for future improvements. The new algorithm is backward-compatible, thus allowing for the reprocessing of historical data sets.

  1. Protein expression-yeast.

    Science.gov (United States)

    Nielsen, Klaus H

    2014-01-01

    Yeast is an excellent system for the expression of recombinant eukaryotic proteins. Both endogenous and heterologous proteins can be overexpressed in yeast (Phan et al., 2001; Ton and Rao, 2004). Because yeast is easy to manipulate genetically, a strain can be optimized for the expression of a specific protein. Many eukaryotic proteins contain posttranslational modifications that can be performed in yeast but not in bacterial expression systems. In comparison with mammalian cell culture expression systems, growing yeast is both faster and less expensive, and large-scale cultures can be performed using fermentation. While several different yeast expression systems exist, this chapter focuses on the budding yeast Saccharomyces cerevisiae and will briefly describe some options to consider when selecting vectors and tags to be used for protein expression. Throughout this chapter, the expression and purification of yeast eIF3 is shown as an example alongside a general scheme outline. © 2014 Elsevier Inc. All rights reserved.

  2. Yeast Infection during Pregnancy

    Science.gov (United States)

    ... OK? What's the best way to treat a yeast infection during pregnancy? Answers from Yvonne Butler Tobah, M.D. You can safely treat a yeast infection during pregnancy with various over-the-counter ...

  3. Yeast (1,3)-(1,6)-beta-glucan helps to maintain the body?s defence against pathogens: a double-blind, randomized, placebo-controlled, multicentric study in healthy subjects

    OpenAIRE

    Auinger, Annegret; Riede, Linda; Bothe, Gordana; Busch, Regina; Gruenwald, Joerg

    2013-01-01

    Purpose The effect of brewers? yeast (1,3)-(1,6)-beta-d-glucan consumption on the number of common cold episodes in healthy subject was investigated. Methods In a placebo-controlled, double-blind, randomized, multicentric clinical trial, 162 healthy participants with recurring infections received 900?mg of either placebo (n?=?81) or an insoluble yeast (1,3)-(1,6)-beta-d-glucan preparation (n?=?81) per day over a course of 16?weeks. Subjects were instructed to document each occurring common co...

  4. Yeast for virus research

    Science.gov (United States)

    Zhao, Richard Yuqi

    2017-01-01

    Budding yeast (Saccharomyces cerevisiae) and fission yeast (Schizosaccharomyces pombe) are two popular model organisms for virus research. They are natural hosts for viruses as they carry their own indigenous viruses. Both yeasts have been used for studies of plant, animal and human viruses. Many positive sense (+) RNA viruses and some DNA viruses replicate with various levels in yeasts, thus allowing study of those viral activities during viral life cycle. Yeasts are single cell eukaryotic organisms. Hence, many of the fundamental cellular functions such as cell cycle regulation or programed cell death are highly conserved from yeasts to higher eukaryotes. Therefore, they are particularly suited to study the impact of those viral activities on related cellular activities during virus-host interactions. Yeasts present many unique advantages in virus research over high eukaryotes. Yeast cells are easy to maintain in the laboratory with relative short doubling time. They are non-biohazardous, genetically amendable with small genomes that permit genome-wide analysis of virologic and cellular functions. In this review, similarities and differences of these two yeasts are described. Studies of virologic activities such as viral translation, viral replication and genome-wide study of virus-cell interactions in yeasts are highlighted. Impacts of viral proteins on basic cellular functions such as cell cycle regulation and programed cell death are discussed. Potential applications of using yeasts as hosts to carry out functional analysis of small viral genome and to develop high throughput drug screening platform for the discovery of antiviral drugs are presented. PMID:29082230

  5. Methane as a Diagnostic Tracer of Changes in the Brewer-Dobson Circulation of the Stratosphere

    Science.gov (United States)

    Remsberg, E. E.

    2015-01-01

    This study makes use of time series of methane (CH4/ data from the Halogen Occultation Experiment (HALOE) to detect whether there were any statistically significant changes of the Brewer-Dobson circulation (BDC) within the stratosphere during 1992-2005. The HALOE CH4 profiles are in terms of mixing ratio versus pressure altitude and are binned into latitude zones within the Southern Hemisphere and the Northern Hemisphere. Their separate time series are then analyzed using multiple linear regression (MLR) techniques. The CH4 trend terms for the Northern Hemisphere are significant and positive at 10 N from 50 to 7 hPa and larger than the tropospheric CH4 trends of about 3%decade(exp -1) from 20 to 7 hPa. At 60 N the trends are clearly negative from 20 to 7 hPa. Their combined trends indicate an acceleration of the BDC in the middle stratosphere of the Northern Hemisphere during those years, most likely due to changes from the effects of wave activity. No similar significant BDC acceleration is found for the Southern Hemisphere. Trends from HALOE H2O are analyzed for consistency. Their mutual trends with CH4 are anti-correlated qualitatively in the middle and upper stratosphere, where CH4 is chemically oxidized to H2O. Conversely, their mutual trends in the lower stratosphere are dominated by their trends upon entry to the tropical stratosphere. Time series residuals for CH4 in the lower mesosphere also exhibit structures that are anti-correlated in some instances with those of the tracer-like species HCl. Their occasional aperiodic structures indicate the effects of transport following episodic, wintertime wave activity. It is concluded that observed multi-year, zonally averaged distributions of CH4 can be used to diagnose major instances of wave-induced transport in the middle atmosphere and to detect changes in the stratospheric BDC.

  6. Variability in the Speed of the Brewer-Dobson Circulation as Observed by Aura/MLS

    Science.gov (United States)

    Flury, Thomas; Wu, Dong L.; Read, W. G.

    2013-01-01

    We use Aura/MLS stratospheric water vapour (H2O) measurements as tracer for dynamics and infer interannual variations in the speed of the Brewer-Dobson circulation (BDC) from 2004 to 2011. We correlate one-year time series of H2O in the lower stratosphere at two subsequent pressure levels (68 hPa, approx.18.8 km and 56 hPa, approx 19.9 km at the Equator) and determine the time lag for best correlation. The same calculation is made on the horizontal on the 100 hPa (approx 16.6 km) level by correlating the H2O time series at the Equator with the ones at 40 N and 40 S. From these lag coefficients we derive the vertical and horizontal speeds of the BDC in the tropics and extra-tropics, respectively. We observe a clear interannual variability of the vertical and horizontal branch. The variability reflects signatures of the Quasi Biennial Oscillation (QBO). Our measurements confirm the QBO meridional circulation anomalies and show that the speed variations in the two branches of the BDC are out of phase and fairly well anti-correlated. Maximum ascent rates are found during the QBO easterly phase. We also find that transport of H2O towards the Northern Hemisphere (NH) is on the average two times faster than to the Southern Hemisphere (SH) with a mean speed of 1.15m/s at 100 hPa. Furthermore, the speed towards the NH shows much more interannual variability with an amplitude of about 21% whilst the speed towards the SH varies by only 10 %. An amplitude of 21% is also observed in the variability of the ascent rate at the Equator which is on the average 0.2mm/s.

  7. Effects of process parameters on the properties of barley containing snacks enriched with brewer's spent grain.

    Science.gov (United States)

    Kirjoranta, Satu; Tenkanen, Maija; Jouppila, Kirsi

    2016-01-01

    Brewer's spent grain (BSG), a by-product of malting of barley in the production of malt extract, was used as an ingredient in extruded barley-based snacks in order to improve the nutritional value of the snacks and widen the applications of this by-product in food sector. The effects of the extrusion parameters on the selected properties of the snacks were studied. Snacks with different ingredients including whole grain barley flour, BSG, whey protein isolate (WPI), barley starch and waxy corn starch were produced in 5 separate trials using a co-rotating twin-screw extruder. Extrusion parameters were water content of the mass (17-23 %), screw speed (200-500 rpm) and temperature of the last section and die (110-150 °C). Expansion, hardness and water content of the snacks were determined. Snacks containing barley flour and BSG (10 % of solids) had small expansion and high hardness. Addition of WPI (20 % of solids) increased expansion only slightly. Snacks with high expansion and small hardness were obtained when part of the barley flour was replaced with starch (barley or waxy corn). Yet, the highest expansion and the smallest hardness were achieved when barley flour was used with barley starch and WPI without BSG. Furthermore, expansion increased by increasing screw speed and decreasing water content of the mass in most of the trials. This study showed that BSG is a suitable material for extruded snacks rich in dietary fiber. Physical properties of the snacks could be improved by using barley or waxy corn starch and WPI.

  8. Comparison of GOME-2/MetOp total ozone data with Brewer spectroradiometer data over the Iberian Peninsula

    Directory of Open Access Journals (Sweden)

    M. Antón

    2009-04-01

    Full Text Available The main objective of this article is to compare the total ozone data from the new Global Ozone Monitoring Experiment instrument (GOME-2/MetOp with reliable ground-based measurement recorded by five Brewer spectroradiometers in the Iberian Peninsula. In addition, a similar comparison for the predecessor instrument GOME/ERS-2 is described. The period of study is a whole year from May 2007 to April 2008. The results show that GOME-2/MetOp ozone data already has a very good quality, total ozone columns are on average 3.05% lower than Brewer measurements. This underestimation is higher than that obtained for GOME/ERS-2 (1.46%. However, the relative differences between GOME-2/MetOp and Brewer measurements show significantly lower variability than the differences between GOME/ERS-2 and Brewer data. Dependencies of these relative differences with respect to the satellite solar zenith angle (SZA, the satellite scan angle, the satellite cloud cover fraction (CF, and the ground-based total ozone measurements are analyzed. For both GOME instruments, differences show no significant dependence on SZA. However, GOME-2/MetOp data show a significant dependence on the satellite scan angle (+1.5%. In addition, GOME/ERS-2 differences present a clear dependence with respect to the CF and ground-based total ozone; such differences are minimized for GOME-2/MetOp. The comparison between the daily total ozone values provided by both GOME instruments shows that GOME-2/MetOp ozone data are on average 1.46% lower than GOME/ERS-2 data without any seasonal dependence. Finally, deviations of a priori climatological ozone profile used by the satellite retrieval algorithm from the true ozone profile are analyzed. Although excellent agreement between a priori climatological and measured partial ozone values is found for the middle and high stratosphere, relative differences greater than 15% are common for the troposphere and lower stratosphere.

  9. Characterisation of corn extrudates with the addition of brewers' spent grain as a raw material for the production of functional batters.

    Science.gov (United States)

    Żelaziński, Tomasz; Ekielski, Adam; Siwek, Adam; Dardziński, Leszek

    2017-01-01

    Novel food batters, recommended for various products, are at present manufactured by extru- sion. Thanks to this, it is possible to look for and process new raw materials, if their processing has so far been considered impossible or economically unviable. The purpose of the work was therefore to investigate the extrudates produced from the corn and brewers' spent grain compounds that are subsequently used as raw material for food batter production. The work presents the findings of research on extrusion of corn mixes with varying levels of brewers' spent grains, to the maximum amount of 30%. Tests were conducted using a co-rotating double screw extruder, equipped with a single-outlet matrix with a diameter of 2.5mm. The products obtained were subjected to analysis of their parameters (apparent density, strength parameters, abrasiveness index) and the granulation of a single fraction was checked. The sample for which the percentage content was the highest was subjected to a detailed analysis of particle shape using vision software. It was found that an increase in the content of brewers' spent grains resulted in increased hardness of the products obtained. During the tests it was observed that the increasing hardness of the measured sam- ples is opposite to their abrasion resistance. The maximum decrement of the brasion parameters was seen for extrudates with 30% spent grain addition and was 1.4%, while the minimum decrement values for extrudates with brewers' grain content (10%) amounted to 0.85%. It was noted that this may prove the high brittleness of such products, particularly on the outer surface. It was also observed that lower grindability was recorded for samples produced by extrusion at a temperature of 140°C. On the other hand, higher grindability obtained at a temperature of 120°C may facilitate the grinding of such products, which may be particularly important in the production of food batter. Brewers' spent grains used as an addition to corn groats

  10. Anti-Saccharomyces cerevisiae antibodies (ASCA) are associated with body fat mass and systemic inflammation, but not with dietary yeast consumption: a cross-sectional study.

    Science.gov (United States)

    Kvehaugen, Anne Stine; Aasbrenn, Martin; Farup, Per G

    2017-01-01

    Baker's/brewer's yeast, Saccharomyces cerevisiae, has been used as an alternative to antibiotic growth promoters to improve growth performance in animals. In humans, Saccharomyces cerevisiae is among the most commonly detected fungi in fecal samples and likely originates from food. Recently, an association between anti-Saccharomyces cerevisiae antibodies (ASCA) and obesity in humans was suggested, but the cause of the elevated ASCA levels is not clear. Our aim was to study ASCA in morbidly obese subjects and explore potential associations with anthropometrics, diet, co-morbidities and biomarkers of inflammation and gut permeability. Subjects with morbid obesity referred to a specialized hospital unit were included. Diet and clinical data were recorded with self-administered questionnaires. Main dietary sources of baker's/brewer's yeast (e.g. bread and beer) were used as a proxy for the intake of yeast. Laboratory analyses included ASCA, serum zonulin (reflecting gut permeability), C-reactive protein and a routine haematological and biochemical screening. One-hundred-and-forty subjects; 109 (78%) female, 98 with dietary records, mean age 43 years and BMI 42 kg/m2 were included. The number of ASCA positive subjects was 31 (22%) for IgG, 4 (2.9%) for IgA and 3 (2.1%) for IgM. Age, body fat mass and C-reactive protein were significantly higher in IgG-positive compared to IgG-negative subjects (P yeast-containing food and ASCA IgG-positivity, or between yeast-containing food and fat mass. The findings indicate that ASCA IgG-positivity may be linked to the generalized inflammation commonly seen with increased adiposity, but not to dietary yeast intake. Other potential causes for the raised ASCA IgG concentrations, such as genetic predisposition, deviations in the gut microbiota and cross-reactivity of ASCA with other antigens, were not explored.

  11. Chemotropism during yeast mating.

    Science.gov (United States)

    Follette, Peter J; Arkowitz, Robert A

    2009-01-01

    Virtually all eukaryotic cells can grow in a polarized fashion in response to external signals. Cells can respond to gradients of chemoattractants or chemorepellents by directional growth, a process referred to as chemotropism. The budding yeast Saccharomyces cerevisiae undergoes chemotropic growth during mating, in which two haploid cells of opposite mating type grow toward one another. We have shown that mating pheromone gradients are essential for efficient mating in yeast and have examined the chemotropism defects of different yeast mutants. Two methods of assessing the ability of yeast strains to respond to pheromone gradients are presented here.

  12. Enhanced ethanol production from brewer's spent grain by a Fusarium oxysporum consolidated system

    Directory of Open Access Journals (Sweden)

    Christakopoulos Paul

    2009-02-01

    Full Text Available Abstract Background Brewer's spent grain (BG, a by-product of the brewing process, is attracting increasing scientific interest as a low-cost feedstock for many biotechnological applications. BG in the present study is evaluated as a substrate for lignocellulolytic enzyme production and for the production of ethanol by the mesophilic fungus Fusarium oxysporum under submerged conditions, implementing a consolidated bioconversion process. Fermentation experiments were performed with sugar mixtures simulating the carbohydrate content of BG in order to determine the utilization pattern that could be expected during the fermentation of the cellulose and hemicellulose hydrolysate of BG. The sugar mixture fermentation study focused on the effect of the initial total sugar concentration and on the effect of the aeration rate on fermenting performance of F. oxysporum. The alkali pretreatment of BG and different aeration levels during the ethanol production stage were studied for the optimization of the ethanol production by F. oxysporum. Results Enzyme yields as high as 550, 22.5, 6.5, 3225, 0.3, 1.25 and 3 U per g of carbon source of endoglucanase, cellobiohydrolase, β-D-glucosidase, xylanase, feruloyl esterase, β-D-xylosidase and α-L-arabinofuranosidase respectively, were obtained during the growth stage under optimized submerged conditions. An ethanol yield of 109 g ethanol per kg of dry BG was obtained with alkali-pretreated BG under microaerobic conditions (0.01 vvm, corresponding to 60% of the theoretical yield based on total glucose and xylose content of BG. Conclusion The enzymatic profile of the extracellular extract from F. oxysporum submerged cultures using BG and corn cob as the carbon source was proved efficient for a successful hydrolysis of BG. The fermentation study carried out using sugar mixtures simulating BG's carbohydrates content and consecutively alkali-pretreated and untreated BG, indicates that BG hydrolysis is the bottleneck

  13. Selection from Industrial Lager Yeast Strains of Variants with Improved Fermentation Performance in Very-High-Gravity Worts▿

    Science.gov (United States)

    Huuskonen, Anne; Markkula, Tuomas; Vidgren, Virve; Lima, Luis; Mulder, Linda; Geurts, Wim; Walsh, Michael; Londesborough, John

    2010-01-01

    There are economic and other advantages if the fermentable sugar concentration in industrial brewery fermentations can be increased from that of currently used high-gravity (ca. 14 to 17°P [degrees Plato]) worts into the very-high-gravity (VHG; 18 to 25°P) range. Many industrial strains of brewer's yeast perform poorly in VHG worts, exhibiting decreased growth, slow and incomplete fermentations, and low viability of the yeast cropped for recycling into subsequent fermentations. A new and efficient method for selecting variant cells with improved performance in VHG worts is described. In this new method, mutagenized industrial yeast was put through a VHG wort fermentation and then incubated anaerobically in the resulting beer while maintaining the α-glucoside concentration at about 10 to 20 g·liter−1 by slowly feeding the yeast maltose or maltotriose until most of the cells had died. When survival rates fell to 1 to 10 cells per 106 original cells, a high proportion (up to 30%) of survivors fermented VHG worts 10 to 30% faster and more completely (residual sugars lower by 2 to 8 g·liter−1) than the parent strains, but the sedimentation behavior and profiles of yeast-derived flavor compounds of the survivors were similar to those of the parent strains. PMID:20081007

  14. Prions in Yeast

    Science.gov (United States)

    Liebman, Susan W.; Chernoff, Yury O.

    2012-01-01

    The concept of a prion as an infectious self-propagating protein isoform was initially proposed to explain certain mammalian diseases. It is now clear that yeast also has heritable elements transmitted via protein. Indeed, the “protein only” model of prion transmission was first proven using a yeast prion. Typically, known prions are ordered cross-β aggregates (amyloids). Recently, there has been an explosion in the number of recognized prions in yeast. Yeast continues to lead the way in understanding cellular control of prion propagation, prion structure, mechanisms of de novo prion formation, specificity of prion transmission, and the biological roles of prions. This review summarizes what has been learned from yeast prions. PMID:22879407

  15. The yeast Golgi apparatus.

    Science.gov (United States)

    Suda, Yasuyuki; Nakano, Akihiko

    2012-04-01

    The Golgi apparatus is an organelle that has been extensively studied in the model eukaryote, yeast. Its morphology varies among yeast species; the Golgi exists as a system of dispersed cisternae in the case of the budding yeast Saccharomyces cerevisiae, whereas the Golgi cisternae in Pichia pastoris and Schizosaccharomyces pombe are organized into stacks. In spite of the different organization, the mechanism of trafficking through the Golgi apparatus is believed to be similar, involving cisternal maturation, in which the resident Golgi proteins are transported backwards while secretory cargo proteins can stay in the cisternae. Questions remain regarding the organization of the yeast Golgi, the regulatory mechanisms that underlie cisternal maturation of the Golgi and transport machinery of cargo proteins through this organelle. Studies using different yeast species have provided hints to these mechanisms. © 2011 John Wiley & Sons A/S.

  16. Sensitivity of Dobson and Brewer Umkehr ozone profile retrievals to ozone cross-sections and stray light effects

    Directory of Open Access Journals (Sweden)

    L. Flynn

    2011-09-01

    Full Text Available Remote sounding methods are used to derive ozone profile and column information from various ground-based and satellite measurements. Vertical ozone profiles measured in Dobson units (DU are currently retrieved based on laboratory measurements of the ozone absorption cross-section spectrum between 270 and 400 nm published in 1985 by Bass and Paur (BP. Recently, the US National Aeronautics and Space Administration (NASA and the European Space Agency (ESA proposed using the set of ozone cross-section measurements made at the Daumont laboratory in 1992 (BDM for revising the Aura Ozone Monitoring Instrument (OMI and Global Ozone Monitoring Experiment (GOME satellite ozone profiles and total ozone column retrievals. Dobson Umkehr zenith sky data have been collected by NOAA ground-based stations at Boulder, CO (BDR and Mauna Loa Observatory, HI (MLO since the 1980s. The UMK04 algorithm is based on the BP ozone cross-section data. It is currently used for all Dobson Umkehr data processing submitted to the World Ozone and Ultraviolet radiation Data Centre (WOUDC under the Global Atmosphere Watch (GAW program of the World Meteorological Organization (WMO. Ozone profiles are also retrieved from measurements by the Mark IV Brewers operated by the NOAA-EPA Brewer Spectrophotometer UV and Ozone Network (NEUBrew using a modified UMK04 algorithm (O3BUmkehr v.2.6, Martin Stanek. This paper describes the sensitivity of the Umkehr retrievals with respect to the proposed ozone cross-section changes. It is found that the ozone cross-section choice only minimally (within the retrieval accuracy affects the Dobson and the Brewer Umkehr retrievals. On the other hand, significantly larger errors were found in the MLO and Boulder Umkehr ozone data (−8 and +5% bias in stratosphere and troposphere respectively when the out-of-band (OOB stray light contribution to the Umkehr measurement is not taken into account (correction is currently not included in the UMK04. The

  17. Evaluation of fermentation quality of brewers' grains ensiled in combination with malt sprouts and chemical conservation additive

    Directory of Open Access Journals (Sweden)

    Ivo Vyskočil

    2008-01-01

    Full Text Available The aim of the work was to evaluate the effect of addition of humidity absorbent (malt sprouts and chemical conservation additive on fermentation process quality of brewer grains’ silage. Chemical conservation additive was based on formic acid, propionic acid, benzoic acid and ammonium formate content. In a model experiment the fresh brewer grains were used. A dry matter (DM content of brewer grains was 187.4 g / kg. Six treatments with three repetitions per treatment were prepared. The treatments A1, A2 and A3 were not supplied by humidity absorbent. Treatment A1 was a control treatment without any additive. The treatments A2 and A3 were supplied by chemical conservation additive in a dose of 3 L per tonne and 6 L per tonne, respectively. The treatments B1, B2 and B3 were supplied by malt sprouts to reach DM content of conserved matter on level 320–350 g / kg. Moreover the treatments B2 and B3 were supplied by chemical additive with its dose 3 and 6 L per tonne. Model silages were evaluated after 8 months of conservation at average laboratory temperature 26–28  °C, from each treatment were the final laboratory samples taken and analyzed. During conservation of treatments B1, B2 and B3 were no drain recognized. From A1 treatment drained 1300 ml of waste fluid that is 145 L per tonne of conserved matter. That was significant (P < 0.01 the malt sprouts addition support the lactic acid production and eliminate acetic acid production. There was no propionic acid or butyric acid detected in silages with malt sprouts event in these silages were analyzed higher (P < 0.01 concentration of ammoniac. Chemical additive supplementation improved (P < 0.01 the pH value and water leach acidity. The results show the malt sprout addition eliminates waste fluid drain and improves fermentation process. The higher concentration of chemical additive (6 l / t inhibited the fermentation process in our model experiment.

  18. Significant Weakening of Brewer-Dobson Circulation Trends Over the 21st Century as a Consequence of the Montreal Protocol

    Science.gov (United States)

    Polvani, Lorenzo M.; Abalos, Marta; Garcia, Rolando; Kinnison, Doug; Randel, William J.

    2018-01-01

    It is well established that increasing greenhouse gases, notably CO2, will cause an acceleration of the stratospheric Brewer-Dobson circulation (BDC) by the end of this century. We here present compelling new evidence that ozone depleting substances are also key drivers of BDC trends. We do so by analyzing and contrasting small ensembles of "single-forcing" integrations with a stratosphere resolving atmospheric model with interactive chemistry, coupled to fully interactive ocean, land, and sea ice components. First, confirming previous work, we show that increasing concentrations of ozone depleting substances have contributed a large fraction of the BDC trends in the late twentieth century. Second, we show that the phasing out of ozone depleting substances in coming decades—as a consequence of the Montreal Protocol—will cause a considerable reduction in BDC trends until the ozone hole is completely healed, toward the end of the 21st century.

  19. [Penicillium-inhibiting yeasts].

    Science.gov (United States)

    Benítez Ahrendts, M R; Carrillo, L

    2004-01-01

    The objective of this work was to establish the in vitro and in vivo inhibition of post-harvest pathogenic moulds by yeasts in order to make a biocontrol product. Post-harvest pathogenic moulds Penicillium digitatum, P. italicum, P. ulaiense, Phyllosticta sp., Galactomyces geotrichum and yeasts belonging to genera Brettanomyces, Candida, Cryptococcus, Kloeckera, Pichia, Rhodotorula were isolated from citrus fruits. Some yeasts strains were also isolated from other sources. The yeasts were identified by their macro and micro-morphology and physiological tests. The in vitro and in vivo activities against P. digitatum or P. ulaiense were different. Candida cantarellii and one strain of Pichia subpelliculosa produced a significant reduction of the lesion area caused by the pathogenic moulds P. digitatum and P. ulaiense, and could be used in a biocontrol product formulation.

  20. Nitrile Metabolizing Yeasts

    Science.gov (United States)

    Bhalla, Tek Chand; Sharma, Monica; Sharma, Nitya Nand

    Nitriles and amides are widely distributed in the biotic and abiotic components of our ecosystem. Nitrile form an important group of organic compounds which find their applications in the synthesis of a large number of compounds used as/in pharmaceutical, cosmetics, plastics, dyes, etc>. Nitriles are mainly hydro-lyzed to corresponding amide/acid in organic chemistry. Industrial and agricultural activities have also lead to release of nitriles and amides into the environment and some of them pose threat to human health. Biocatalysis and biotransformations are increasingly replacing chemical routes of synthesis in organic chemistry as a part of ‘green chemistry’. Nitrile metabolizing organisms or enzymes thus has assumed greater significance in all these years to convert nitriles to amides/ acids. The nitrile metabolizing enzymes are widely present in bacteria, fungi and yeasts. Yeasts metabolize nitriles through nitrilase and/or nitrile hydratase and amidase enzymes. Only few yeasts have been reported to possess aldoxime dehydratase. More than sixty nitrile metabolizing yeast strains have been hither to isolated from cyanide treatment bioreactor, fermented foods and soil. Most of the yeasts contain nitrile hydratase-amidase system for metabolizing nitriles. Transformations of nitriles to amides/acids have been carried out with free and immobilized yeast cells. The nitrilases of Torulopsis candida>and Exophiala oligosperma>R1 are enantioselec-tive and regiospecific respectively. Geotrichum>sp. JR1 grows in the presence of 2M acetonitrile and may have potential for application in bioremediation of nitrile contaminated soil/water. The nitrilase of E. oligosperma>R1 being active at low pH (3-6) has shown promise for the hydroxy acids. Immobilized yeast cells hydrolyze some additional nitriles in comparison to free cells. It is expected that more focus in future will be on purification, characterization, cloning, expression and immobilization of nitrile metabolizing

  1. Forces in yeast flocculation

    Science.gov (United States)

    El-Kirat-Chatel, Sofiane; Beaussart, Audrey; Vincent, Stéphane P.; Abellán Flos, Marta; Hols, Pascal; Lipke, Peter N.; Dufrêne, Yves F.

    2015-01-01

    In the baker's yeast Saccharomyces cerevisiae, cell-cell adhesion (``flocculation'') is conferred by a family of lectin-like proteins known as the flocculin (Flo) proteins. Knowledge of the adhesive and mechanical properties of flocculins is important for understanding the mechanisms of yeast adhesion, and may help controlling yeast behaviour in biotechnology. We use single-molecule and single-cell atomic force microscopy (AFM) to explore the nanoscale forces engaged in yeast flocculation, focusing on the role of Flo1 as a prototype of flocculins. Using AFM tips labelled with mannose, we detect single flocculins on Flo1-expressing cells, showing they are widely exposed on the cell surface. When subjected to force, individual Flo1 proteins display two distinct force responses, i.e. weak lectin binding forces and strong unfolding forces reflecting the force-induced extension of hydrophobic tandem repeats. We demonstrate that cell-cell adhesion bonds also involve multiple weak lectin interactions together with strong unfolding forces, both associated with Flo1 molecules. Single-molecule and single-cell data correlate with microscale cell adhesion behaviour, suggesting strongly that Flo1 mechanics is critical for yeast flocculation. These results favour a model in which not only weak lectin-sugar interactions are involved in yeast flocculation but also strong hydrophobic interactions resulting from protein unfolding.

  2. Comparison of UV irradiances from Aura/Ozone Monitoring Instrument (OMI with Brewer measurements at El Arenosillo (Spain – Part 1: Analysis of parameter influence

    Directory of Open Access Journals (Sweden)

    M. Antón

    2010-07-01

    Full Text Available The main objective of this study is to compare the erythemal UV irradiance (UVER and spectral UV irradiances (at 305, 310 and 324 nm from the Ozone Monitoring Instrument (OMI onboard NASA EOS/Aura polar sun-synchronous satellite (launched in July 2004, local equator crossing time 01:45 p.m. with ground-based measurements from the Brewer spectrophotometer #150 located at El Arenosillo (South of Spain. The analyzed period comprises more than four years, from October 2004 to December 2008. The effects of several factors (clouds, aerosols and the solar elevation on OMI-Brewer comparisons were analyzed. The proxies used for each factor were: OMI Lambertian Equivalent Reflectivity (LER at 360 nm (clouds, the aerosol optical depth (AOD at 440 nm measured from the ground-based Cimel sun-photometer (http://aeronet.gsfc.nasa.gov, and solar zenith angle (SZA at OMI overpass time. The comparison for all sky conditions reveals positive biases (OMI higher than Brewer 12.3% for UVER, 14.2% for UV irradiance at 305 nm, 10.6% for 310 nm and 8.7% for 324 nm. The OMI-Brewer root mean square error (RMSE is reduced when cloudy cases are removed from the analysis, (e.g., RMSE~20% for all sky conditions and RMSE smaller than 10% for cloud-free conditions. However, the biases remain and even become more significant for the cloud-free cases with respect to all sky conditions. The mentioned overestimation is partially due to aerosol extinction influence. In addition, the differences OMI-Brewer typically decrease with SZA except days with high aerosol loading, when the bias is near constant. The seasonal dependence of the OMI-Brewer difference for cloud-free conditions is driven by aerosol climatology.

    To account for the aerosol effect, a first evaluation in order to compare with previous TOMS results (Antón et al., 2007 was performed. This comparison shows that the OMI bias is between +14% and +19% for

  3. Monitoring yeast physiology during very high gravity wort fermentations by frequent analysis of gene expression.

    Science.gov (United States)

    Rautio, Jari J; Huuskonen, Anne; Vuokko, Heikki; Vidgren, Virve; Londesborough, John

    2007-09-01

    Brewer's yeast experiences constantly changing environmental conditions during wort fermentation. Cells can rapidly adapt to changing surroundings by transcriptional regulation. Changes in genomic expression can indicate the physiological condition of yeast in the brewing process. We monitored, using the transcript analysis with aid of affinity capture (TRAC) method, the expression of some 70 selected genes relevant to wort fermentation at high frequency through 9-10 day fermentations of very high gravity wort (25 degrees P) by an industrial lager strain. Rapid changes in expression occurred during the first hours of fermentations for several genes, e.g. genes involved in maltose metabolism, glycolysis and ergosterol synthesis were strongly upregulated 2-6 h after pitching. By the time yeast growth had stopped (72 h) and total sugars had dropped by about 50%, most selected genes had passed their highest expression levels and total mRNA was less than half the levels during growth. There was an unexpected upregulation of some genes of oxygen-requiring pathways during the final fermentation stages. For five genes, expression of both the Saccharomyces cerevisiae and S. bayanus components of the hybrid lager strain were determined. Expression profiles were either markedly different (ADH1, ERG3) or very similar (MALx1, ILV5, ATF1) between these two components. By frequent analysis of a chosen set of genes, TRAC provided a detailed and dynamic picture of the physiological state of the fermenting yeast. This approach offers a possible way to monitor and optimize the performance of yeast in a complex process environment. Copyright (c) 2007 John Wiley & Sons, Ltd.

  4. Yeasts associated with Manteca.

    Science.gov (United States)

    Suzzi, Giovanna; Schirone, Maria; Martuscelli, Maria; Gatti, Monica; Fornasari, Maria Emanuela; Neviani, Erasmo

    2003-04-01

    Manteca is a traditional milk product of southern Italy produced from whey deriving from Caciocavallo Podolico cheese-making. This study was undertaken to obtain more information about the microbiological properties of this product and particularly about the presence, metabolic activities, and technological significance of the different yeast species naturally occurring in Manteca. High numbers of yeasts were counted after 7 days ripening (10(4)-10(5) cfu g(-1)) and then decreased to 10(2) at the end. A total of 179 isolates were identified and studied for their phenotypic and genotypic characteristics. The most frequently encountered species were Trichosporon asahii (45), Candida parapsilosis (33), Rhodotorula mucilaginosa (32), Candida inconspicua (29). Some of these yeasts showed lipolytic activity (32 strains) and proteolytic activity (29 strains), NaCl resistance up to 10% and growth up to 45 degrees C (42 strains). Biogenic amines were formed by proteolytic strains, in particular phenylethylamine, putrescine and spermidine. Spermidine was produced by all the yeasts tested in this work, but only Trichosporon produced a great quantity of this compound. Histamine was not detectable. Caseinolytic activity was common to almost all strains, corresponding to the ability to efficiently split off amino-terminal amino acids. The highest and most constant activity expressed by all species was X-prolyl-dipeptidyl aminopeptidase. The findings suggest that the presence of yeasts may play a significant role in justifying interactions with lactic acid bacteria, and consequently with their metabolic activity in the definition of the peculiar characteristics of Manteca cheese.

  5. Yeast genome sequencing:

    DEFF Research Database (Denmark)

    Piskur, Jure; Langkjær, Rikke Breinhold

    2004-01-01

    they are short and degenerate and occupy different positions. Comparative genomics helps to understand the origin of yeasts and points out crucial molecular events in yeast evolutionary history, such as whole-genome duplication and horizontal gene transfer(s). In addition, the accumulating sequence data provide...... that the minimum number of genes from each species that need to be compared to produce a reliable phylogeny is about 20. Yeast has also become an attractive model to study speciation in eukaryotes, especially to understand molecular mechanisms behind the establishment of reproductive isolation. Comparison...... of closely related species helps in gene annotation and to answer how many genes there really are within the genomes. Analysis of non-coding regions among closely related species has provided an example of how to determine novel gene regulatory sequences, which were previously difficult to analyse because...

  6. Novel trends in electrocatalysis: Extended Brewer hypo-hyper-d-interionic bonding theory and selective interactive grafting of composite bifunctional electrocatalysts for simultaneous anodic hydrogen

    Directory of Open Access Journals (Sweden)

    Neophytides S.G.

    2003-01-01

    Full Text Available Novel Trends in Electrocatalysis: Extended Brewer Hypo-Hyper-d-lnterionic Bonding Theory and Selective Interactive Grafting of Composite Bifunctional Electrocatalysts for Simultaneous Anodic Hydrogen and CO OxidationThe Extended Brewer Interactive Interionic Bonding Theory (EBIIBT has been developed to show the equivalence of interatomic and interionic bonding features, and for their mutual combinations, as well as its effect upon electrocatalytic properties for the hydrogen electrode reactions (HELR. The equivalence of interionic hypo-hyper-d-interelectronic interaction in both metallic and any other ionic state and its effect upon electrocatalytic properties for hydrogen electrode reactions (HELR has been proved and inferred. TG (Thermal Gravimetry analysis of TPR (Temperature Programmed Reduction of mixed hypc-hyper-d-electronic oxides of transition elements was broadly employed to prove the EBIIBT effect as reflected in dramatically decreased individual temperatures of their mutual reduction into intermetallic phases. The same interionic Brewer (and/or intermetallic bonding effect has been confirmed both by UPD of hyper-d-upon hypo-d-electronic substrates and vice versa, and by the shift of bonding peaks in XPS analysis.

  7. Methane emissions from two breeds of beef cows offered diets containing barley straw with either grass silage or brewers' grains.

    Science.gov (United States)

    Duthie, C-A; Rooke, J A; Hyslop, J J; Waterhouse, A

    2015-10-01

    Increasing the concentration of dietary lipid is a promising strategy for reducing methane (CH4) emissions from ruminants. This study investigated the effect of replacing grass silage with brewers' grains on CH4 emissions of pregnant, non-lactating beef cows of two breeds. The experiment was a two×two factorial design comprising two breeds (LIMx, crossbred Limousin; and LUI, purebred Luing) and two diets consisting of (g/kg diet dry matter (DM)) barley straw (687) and grass silage (301, GS), or barley straw (763) and brewers' grains (226, BG), which were offered ad libitum. Replacing GS with BG increased the acid-hydrolysed ether extract concentration from 21 to 37 g/kg diet DM. Cows (n=48) were group-housed in equal numbers of each breed across two pens and each diet was allocated to one pen. Before measurements of CH4, individual dry matter intake (DMI), weekly BW and weekly body condition score were measured for a minimum of 3 weeks, following a 4-week period to acclimatise to the diets. CH4 emissions were subsequently measured on one occasion from each cow using individual respiration chambers. Due to occasional equipment failures, CH4 measurements were run over 9 weeks giving 10 observations for each breed×treatment combination (total n=40). There were no differences between diets for daily DMI measured in the chambers (9.92 v. 9.86 kg/day for BG and GS, respectively; P>0.05). Cows offered the BG diet produced less daily CH4 than GS-fed cows (131 v. 156 g/day: P0.05). However, when expressed as a proportion of metabolic BW (BW0.75), LUI cows had greater DMI than LIMx cows (84.5 v. 75.7 g DMI/kg BW0.75, Pcows (1.30 v. 1.05 g CH4/kg BW0.75; Pcows. This study demonstrated that replacing GS with BG in barley straw-based diets can effectively reduce CH4 emissions from beef cows, with no suppression of DMI.

  8. Genetics of Yeasts

    Science.gov (United States)

    Querol, Amparo; Fernández-Espinar, M. Teresa; Belloch, Carmela

    The use of yeasts in biotechnology processes dates back to ancient days. Before 7000 BC, beer was produced in Sumeria. Wine was made in Assyria in 3500 BC, and ancient Rome had over 250 bakeries, which were making leavened bread by 100 BC. And milk has been made into Kefyr and Koumiss in Asia for many centuries (Demain, Phaff, & Kurtzman, 1999). However, the importance of yeast in the food and beverage industries was only realized about 1860, when their role in food manufacturing became evident.

  9. L-arabinose fermenting yeast

    Science.gov (United States)

    Zhang, Min; Singh, Arjun; Knoshaug, Eric; Franden, Mary Ann; Jarvis, Eric; Suominen, Pirkko

    2010-12-07

    An L-arabinose utilizing yeast strain is provided for the production of ethanol by introducing and expressing bacterial araA, araB and araD genes. L-arabinose transporters are also introduced into the yeast to enhance the uptake of arabinose. The yeast carries additional genomic mutations enabling it to consume L-arabinose, even as the only carbon source, and to produce ethanol. Methods of producing ethanol include utilizing these modified yeast strains. ##STR00001##

  10. Assessment of yeast as a dietary additive on haematology and water quality of common carp in a recirculating aquaculture system

    Science.gov (United States)

    Goran, Siraj Muhammed Abdulla; Omar, Samad Sofy; Anwer, Ayub Youns

    2017-09-01

    Feeding experiment was accomplished at the Aquaculture unit (Close system), Grdarasha station, Agriculture College, University of Salahaddin, Erbil, Kurdistan Region, to investigate different levels of Aquagrow E (AGEY) brewer's yeast cell Saccharomyces cerevisiae on the haematological and water quality of common carp fingerlings Cyprinus carpio. The basal diet was formulated to contain 34% protein and 10% lipid and the dietary treatments were supplemented with 0.5%, 1% and 1.5% of AGEY diet. A total of 180 Common carp (10.30 ± 0.27 g) fed on experimental diets for 10 weeks. Water quality assessment for well water and pond water for rearing Cyprinus carpio in cage system conducted weekly, while some parameters including pH, EC, water temperature and DO were monitored daily during the entire periods of study. Values of total hardness, alkalinity, ammonia and nitrate for studied water samples were within normal ranges for rearing Cyprinus carpio. Mean concentration of GPT, GOT and Glucose were 104 to 170 U/L, 1371 to 3308 U/L and 34 to 63mg/dl respectively, moreover, highest levels were observed in treatments with higher concentrations of yeast in its food except for blood sugar. Slight variation in lipase enzyme were found between control and treatment groups, while levels of amylase enzyme were increased toward cages with higher levels of yeast until T1 and then decreased toward T3. Total protein levels were increased to toward higher levels of yeast in food of Cyprinus carpio fish. Haematological results showed highest levels of WBC and platelets in treatments cages than control group. Levels of RBCs and hemoglobin were highest in treatment group 1 with 0.5%of yeast than treatments higher yeast concentrations. Significant correlation was found in haematological parameters between control and treatments.

  11. Variation in Brewer-Dobson circulation during three sudden stratospheric major warming events in the 2000s

    Science.gov (United States)

    Tao, Mengchu; Liu, Yi; Zhang, Yuli

    2017-12-01

    As the strongest subseasonal atmospheric variability during boreal winter, three remarkable sudden stratospheric major warming (SSW) events in the 2000s are investigated in terms of the Brewer-Dobson circulation (BDC) response. Our study shows that the changes of cross-isentropic velocity during the SSWs are not only confined to the polar region, but also extend to the whole Northern Hemisphere: enhanced descent in the polar region, as well as enhanced ascent in the tropics. When the acceleration of the deep branch of the BDC descends to the middle stratosphere, its strength rapidly decreases over a period of one to two weeks. The acceleration of the deep branch of the BDC is driven by the enhanced planetary wave activity in the mid-to-high-latitude stratosphere. Different from the rapid response of the deep branch of the BDC, tropical upwelling in the lower stratosphere accelerates up to 20%-40% compared with the climatology, 20-30 days after the onset of the SSWs, and the acceleration lasts for one to three months. The enhancement of tropical upwelling is associated with the large-scale wave-breaking in the subtropics interacting with the midlatitude and tropical Quasi-Biennial Oscillation-related mean flow.

  12. Effect of pH on the solubilization of brewers' spent grain by microbial carbohydrases and proteases.

    Science.gov (United States)

    Faulds, Craig B; Robertson, James A; Waldron, Keith W

    2008-08-27

    The potential for enzymatic solubilization of brewers' spent grain by carbohydrases and proteases was examined over a broad pH range (pH 3.2-11.2). Enzymes from Trichoderma (Depol 686) were most efficient at a lower pH, while enzymes from the Humicola preparation (Depol 740) were the best performer over the whole range. Profiling of key glycoside hydrolase, esterase and protease activities across the pH range demonstrated that solubilization of spent grain by the Trichoderma enzymes corresponded to the range of maximum activities. This was not the case with the Humicola enzymes, where maximum solubilization of the substrate occurred at pH 9.1, at which pH the determined activities were low. Protease activity in Depol 740 was associated with a high solubilization, but inhibition of proteolytic activity resulted in only a 5% decrease in spent grain solubilization. These results suggest that while enzymes can be used to exploit agro-industrials byproduct, the use of high pH increases the extent of hydrolysis and an unidentified factor produced by Humicola improves the enzyme-catalyzed solubilization of lignocellulosic material.

  13. Opportunistic Pathogenic Yeasts

    Science.gov (United States)

    Banerjee, Uma

    Advances in medical research, made during the last few decades, have improved the prophylactic, diagnostic and therapeutic capabilities for variety of infections/diseases. However, many of the prophylactic and therapeutic procedures have been seen in many instances to exact a price of host-vulnerability to an expanding group of opportunistic pathogens and yeasts are one of the important members in it. Fortunately amongst the vast majority of yeasts present in nature only few are considered to have the capability to cause infections when certain opportunities predisposes and these are termed as ‘opportunistic pathogenic yeasts.’ However, the term ‘pathogenic’ is quite tricky, as it depends of various factors of the host, the ‘bug’ and the environment to manifest the clinical infection. The borderline is expanding. In the present century with unprecedented increase in number of immune-compromised host in various disciplines of health care settings, where any yeast, which has the capability to grow at 37 ° C (normal body temperature of human), can be pathogenic and cause infection in particular situation

  14. Recombinant wine yeasts

    OpenAIRE

    González García, Ramón; González Ramos, Daniel

    2008-01-01

    The invention relates to a method for obtaining strains that secrete a higher concentration of mannoproteins to the medium, a Saccharomyces cerevisiae yeast strain deposited at the Spanish Type Culture Collection (CECT) as CECT 13012, and to the uses of said strains.

  15. Proteolytic activities in yeast.

    Science.gov (United States)

    Saheki, T; Holzer, H

    1975-03-28

    Studies on the mechanism and time course of the activation of proteinases A (EC 3.4.23.8), B (EC 3.4.22.9) and C (EC 3.4.12.--) in crude yeast extracts at pH 5.1 and 25 degrees C showed that the increase in proteinase B activity is paralleled with the disappearance of proteinase B inhibitor. Addition of purified proteinase A to fresh crude extracts accelerates the inactivation of the proteinase B inhibitor and the appearance of maximal activities of proteinases B and C. The decrease of proteinase B inhibitor activity and the increase of proteinase B activity are markedly retarded by the addition of pepstatin. Because 10-minus 7 M pepstatin completely inhibits proteinase A without affecting proteinase B activity, this is another indication for the role of proteinase A during the activation of proteinase B. Whereas extracts of yeast grown on minimal medium reached maximal activation of proteinases B and C after 20 h of incubation at pH 5.1 and 25 degrees C, extracts of yeast grown on complete medium had to be incubated for about 100 h. In the latter case, the addition of proteinas A results in maximal activation of proteinases B and C and disappearance of proteinase B inhibitor activity only after 10--20 h of incubation. With the optimal conditions, the maximal activities of proteinases A, B and C, as well as of the proteinase B inhibitor, were determined in crude extracts of yeast that had been grown batchwise for different lengths of time either on minimal or on complete medium. Upon incubation, all three proteinases were activated by several times their initial activity. This reflects the existence of proteolytically degradable inhibitors of the three proteinases and together with the above mentioned observations it demonstrates that the "activation" of yeast proteinases A, B and C upon incubation results from the proteolytic digestion of inhibitors rather than from activation of inactive zymogens by limited proteolysis.

  16. L-arabinose fermenting yeast

    Science.gov (United States)

    Zhang, Min; Singh, Arjun; Suominen, Pirkko; Knoshaug, Eric; Franden, Mary Ann; Jarvis, Eric

    2013-02-12

    An L-arabinose utilizing yeast strain is provided for the production of ethanol by introducing and expressing bacterial araA, araB and araD genes. L-arabinose transporters are also introduced into the yeast to enhance the uptake of arabinose. The yeast carries additional genomic mutations enabling it to consume L-arabinose, even as the only carbon source, and to produce ethanol. A yeast strain engineered to metabolize arabinose through a novel pathway is also disclosed. Methods of producing ethanol include utilizing these modified yeast strains.

  17. Yeast ecology of Kombucha fermentation.

    Science.gov (United States)

    Teoh, Ai Leng; Heard, Gillian; Cox, Julian

    2004-09-01

    Kombucha is a traditional fermentation of sweetened tea, involving a symbiosis of yeast species and acetic acid bacteria. Despite reports of different yeast species being associated with the fermentation, little is known of the quantitative ecology of yeasts in Kombucha. Using oxytetracycline-supplemented malt extract agar, yeasts were isolated from four commercially available Kombucha products and identified using conventional biochemical and physiological tests. During the fermentation of each of the four products, yeasts were enumerated from both the cellulosic pellicle and liquor of the Kombucha. The number and diversity of species varied between products, but included Brettanomyces bruxellensis, Candida stellata, Schizosaccharomyces pombe, Torulaspora delbrueckii and Zygosaccharomyces bailii. While these yeast species are known to occur in Kombucha, the enumeration of each species present throughout fermentation of each of the four Kombucha cultures demonstrated for the first time the dynamic nature of the yeast ecology. Kombucha fermentation is, in general, initiated by osmotolerant species, succeeded and ultimately dominated by acid-tolerant species.

  18. Filtration, haze and foam characteristics of fermented wort mediated by yeast strain.

    Science.gov (United States)

    Douglas, P; Meneses, F J; Jiranek, V

    2006-01-01

    To investigate the influence of the choice of yeast strain on the haze, shelf life, filterability and foam quality characteristics of fermented products. Twelve strains were used to ferment a chemically defined wort and hopped ale or stout wort. Fermented products were assessed for foam using the Rudin apparatus, and filterability and haze characteristics using the European Brewing Convention methods, to reveal differences in these parameters as a consequence of the choice of yeast strain and growth medium. Under the conditions used, the choice of strain of Saccharomyces cerevisiae effecting the primary fermentation has an impact on all of the parameters investigated, most notably when the fermentation medium is devoid of macromolecular material. The filtration of fermented products has a large cost implication for many brewers and wine makers, and the haze of the resulting filtrate is a key quality criterion. Also of importance to the quality of beer and some wines is the foaming and head retention of these beverages. The foam characteristics, filterability and potential for haze formation in a fermented product have long been known to be dependant on the raw materials used, as well as other production parameters. The choice of Saccharomyces cerevisiae strain used to ferment has itself been shown here to influence these parameters.

  19. Extracellular Polysaccharides Produced by Yeasts and Yeast-Like Fungi

    Science.gov (United States)

    van Bogaert, Inge N. A.; de Maeseneire, Sofie L.; Vandamme, Erick J.

    Several yeasts and yeast-like fungi are known to produce extracellular polysaccharides. Most of these contain D-mannose, either alone or in combination with other sugars or phosphate. A large chemical and structural variability is found between yeast species and even among different strains. The types of polymers that are synthesized can be chemically characterized as mannans, glucans, phosphoman-nans, galactomannans, glucomannans and glucuronoxylomannans. Despite these differences, almost all of the yeast exopolysaccharides display some sort of biological activity. Some of them have already applications in chemistry, pharmacy, cosmetics or as probiotic. Furthermore, some yeast exopolysaccharides, such as pullulan, exhibit specific physico-chemical and rheological properties, making them useful in a wide range of technical applications. A survey is given here of the production, the characteristics and the application potential of currently well studied yeast extracellular polysaccharides.

  20. Yeasts in Hevea brasiliensis Latex.

    Science.gov (United States)

    Glushakova, A M; Kachalkin, A V; Maksimova, I A; Chernov, I Yu

    2016-07-01

    Yeast abundance and species diversity in the latex of caoutchouc tree Hevea brasiliensis (Willd. ex Juss.) M611. Arg., on its green leaves, and in soil below the plant Was studied. The yeasts present in the fresh latex in concentrations of up to 5.5 log(CFU/g) were almost exclusively represented by the species Candida heveicola, which was previously isolated from Hevea latex in China. In the course of natural modification of the latex yeast diversity increased, while yeast abundance decreased. The yeasts of thickened and solidified latex were represented by typical epiphytic and ubiquitous species: Kodamea ohmeri, Debaryomyces hansenii, Rhodotorula mucilaginosa, and synanthropic species Candida parapsilosis and Cutaneotrichosporon arbori- formis. The role of yeasts in latex modification at the initial stages of succession and their probable role in de- velopment of antifungal activity in the latex are discussed.

  1. Yeast interactions and wine flavour.

    Science.gov (United States)

    Fleet, Graham H

    2003-09-01

    Wine is the product of complex interactions between fungi, yeasts and bacteria that commence in the vineyard and continue throughout the fermentation process until packaging. Although grape cultivar and cultivation provide the foundations of wine flavour, microorganisms, especially yeasts, impact on the subtlety and individuality of the flavour response. Consequently, it is important to identify and understand the ecological interactions that occur between the different microbial groups, species and strains. These interactions encompass yeast-yeast, yeast-filamentous fungi and yeast-bacteria responses. The surface of healthy grapes has a predominance of Aureobasidium pullulans, Metschnikowia, Hanseniaspora (Kloeckera), Cryptococcus and Rhodotorula species depending on stage of maturity. This microflora moderates the growth of spoilage and mycotoxigenic fungi on grapes, the species and strains of yeasts that contribute to alcoholic fermentation, and the bacteria that contribute to malolactic fermentation. Damaged grapes have increased populations of lactic and acetic acid bacteria that impact on yeasts during alcoholic fermentation. Alcoholic fermentation is characterised by the successional growth of various yeast species and strains, where yeast-yeast interactions determine the ecology. Through yeast-bacterial interactions, this ecology can determine progression of the malolactic fermentation, and potential growth of spoilage bacteria in the final product. The mechanisms by which one species/strain impacts on another in grape-wine ecosystems include: production of lytic enzymes, ethanol, sulphur dioxide and killer toxin/bacteriocin like peptides; nutrient depletion including removal of oxygen, and production of carbon dioxide; and release of cell autolytic components. Cell-cell communication through quorum sensing molecules needs investigation.

  2. Flavour-active wine yeasts

    OpenAIRE

    Cordente, Antonio G.; Curtin, Christopher D.; Varela, Cristian; Pretorius, Isak S.

    2012-01-01

    The flavour of fermented beverages such as beer, cider, saké and wine owe much to the primary fermentation yeast used in their production, Saccharomyces cerevisiae. Where once the role of yeast in fermented beverage flavour was thought to be limited to a small number of volatile esters and higher alcohols, the discovery that wine yeast release highly potent sulfur compounds from non-volatile precursors found in grapes has driven researchers to look more closely at how choice of yeast can infl...

  3. Yeast Infections: MedlinePlus Health Topic

    Science.gov (United States)

    ... Vaginal yeast infection (Medical Encyclopedia) Also in Spanish Topic Image MedlinePlus Email Updates Get Yeast Infections updates ... gram stain Thrush Vaginal yeast infection Related Health Topics Fungal Infections Vaginitis National Institutes of Health The ...

  4. Paraphyly and (yeast) classification.

    Science.gov (United States)

    Lachance, Marc-André

    2016-12-01

    Yeast systematics has wholeheartedly embraced the phylogenetic approach. Central to this has been the unspoken convention that taxa at all ranks be strictly monophyletic. This can result in a proliferation of small genera and instances of nomenclatural instability, counter to the expected benefit of phylogenetic systematics. But the literature abounds with examples, at all taxonomic levels, where paraphyly is a reality that can no longer be ignored. The very concepts of Bacteria or Archaea, under the constraint of monophyly, are in peril. It is therefore desirable to effect a shift in practices that will recognize the existence of paraphyletic taxa.

  5. Inheritance of the yeast mitochondrial genome

    DEFF Research Database (Denmark)

    Piskur, Jure

    1994-01-01

    Mitochondrion, extrachromosomal genetics, intergenic sequences, genome size, mitochondrial DNA, petite mutation, yeast......Mitochondrion, extrachromosomal genetics, intergenic sequences, genome size, mitochondrial DNA, petite mutation, yeast...

  6. Yeasts preservation: alternatives for lyophilisation

    NARCIS (Netherlands)

    Nyanga, L.K.; Nout, M.J.R.; Smid, E.J.; Boekhout, T.; Zwietering, M.H.

    2012-01-01

    The aim of the study was to compare the effect of two low-cost, low technology traditional methods for drying starter cultures with standard lyophilisation. Lyophilised yeast cultures and yeast cultures preserved in dry rice cakes and dry plant fibre strands were examined for viable cell counts

  7. Sociobiology of the budding yeast

    Indian Academy of Sciences (India)

    ... the unicellular yeast Saccharomyces cerevisiae, for sociobiological research. I discuss the problems connected with clear classification of yeast behaviour based on the fitness-based Hamilton paradigm. Relevant traits include different types of communities, production of flocculins, invertase and toxins, and the presence ...

  8. Mitochondria autophagy in yeast.

    Science.gov (United States)

    Kanki, Tomotake; Klionsky, Daniel J; Okamoto, Koji

    2011-05-15

    The mitochondrion is an organelle that carries out a number of important metabolic processes such as fatty acid oxidation, the citric acid cycle, and oxidative phosphorylation. However, this multitasking organelle also generates reactive oxygen species (ROS), which can cause oxidative stress resulting in self-damage. This type of mitochondrial damage can lead to the further production of ROS and a resulting downward spiral with regard to mitochondrial capability. This is extremely problematic because the accumulation of dysfunctional mitochondria is related to aging, cancer, and neurodegenerative diseases. Accordingly, appropriate quality control of this organelle is important to maintain proper cellular homeostasis. It has been thought that selective mitochondria autophagy (mitophagy) contributes to the maintenance of mitochondrial quality by eliminating damaged or excess mitochondria, although little is known about the mechanism. Recent studies in yeast identified several mitophagy-related proteins, which have been characterized with regard to their function and regulation. In this article, we review recent advances in the physiology and molecular mechanism of mitophagy and discuss the similarities and differences of this degradation process between yeast and mammalian cells.

  9. Flocculation and haze removal from crude beer using in-house produced laccase from Trametes versicolor cultured on brewer's spent grain.

    Science.gov (United States)

    Dhillon, Gurpreet Singh; Kaur, Surinder; Brar, Satinder Kaur; Verma, Mausam

    2012-08-15

    The potential of brewer's spent grain (BSG), a common waste from the brewing industry, as a support-substrate for laccase production by the well-known laccase producer Trametes versicolor ATCC 20869 under solid-state fermentation conditions was assessed. An attempt was made to improve the laccase production by T. versicolor through supplementing the cultures with inducers, such as 2,2-azino bis(3-ethylbenzthiazoline-6-sulfonic acid), copper sulfate, ethanol, gallic acid, veratryl alcohol, and phenol. A higher laccase activity of 13506.2 ± 138.2 IU/gds (gram dry substrate) was obtained with a phenol concentration of 10 mg/kg substrate in a tray bioreactor after 12 days of incubation time. The flocculation properties of the laccase treated crude beer samples have been studied by using various parameters, such as viscosity, turbidity, ζ potential, total polyphenols, and total protein content. The present results indicated that laccase (25 IU/L) showed promising results as a good flocculating agent. The laccase treatment showed better flocculation capacity compared to the industrial flocculation process using stabifix as a flocculant. The laccase treatments (25 IU/L) at 4 ± 1 °C and room temperature have shown almost similar flocculation properties without much variability. The study demonstrated the potential of in-house produced laccase using brewer's spent grain for the clarification and flocculation of crude beer as a sustainable alternative to traditional flocculants, such as stabifix and bentonite.

  10. Yeast (1,3)-(1,6)-beta-glucan helps to maintain the body's defence against pathogens: a double-blind, randomized, placebo-controlled, multicentric study in healthy subjects.

    Science.gov (United States)

    Auinger, Annegret; Riede, Linda; Bothe, Gordana; Busch, Regina; Gruenwald, Joerg

    2013-12-01

    The effect of brewers' yeast (1,3)-(1,6)-beta-D-glucan consumption on the number of common cold episodes in healthy subject was investigated. In a placebo-controlled, double-blind, randomized, multicentric clinical trial, 162 healthy participants with recurring infections received 900 mg of either placebo (n = 81) or an insoluble yeast (1,3)-(1,6)-beta-D-glucan preparation (n = 81) per day over a course of 16 weeks. Subjects were instructed to document each occurring common cold episode in a diary and to rate ten predefined infection symptoms during an infections period, resulting in a symptom score. The subjects were examined by the investigator during the episode visit on the 5th day of each cold episode. In the per protocol population, supplementation with insoluble yeast (1,3)-(1,6)-beta-glucan reduced the number of symptomatic common cold infections by 25% as compared to placebo (p = 0.041). The mean symptom score was 15% lower in the beta-glucan as opposed to the placebo group (p = 0.125). Beta-glucan significantly reduced sleep difficulties caused by cold episode as compared to placebo (p = 0.028). Efficacy of yeast beta-glucan was rated better than the placebo both by physicians (p = 0.004) participants (p = 0.012). The present study demonstrated that yeast beta-glucan preparation increased the body's potential to defend against invading pathogens.

  11. Production of Food Grade Yeasts

    Directory of Open Access Journals (Sweden)

    Argyro Bekatorou

    2006-01-01

    Full Text Available Yeasts have been known to humans for thousands of years as they have been used in traditional fermentation processes like wine, beer and bread making. Today, yeasts are also used as alternative sources of high nutritional value proteins, enzymes and vitamins, and have numerous applications in the health food industry as food additives, conditioners and flavouring agents, for the production of microbiology media and extracts, as well as livestock feeds. Modern scientific advances allow the isolation, construction and industrial production of new yeast strains to satisfy the specific demands of the food industry. Types of commercial food grade yeasts, industrial production processes and raw materials are highlighted. Aspects of yeast metabolism, with respect to carbohydrate utilization, nutritional aspects and recent research advances are also discussed.

  12. Red yeast rice for dysipidemia.

    Science.gov (United States)

    Shamim, Shariq; Al Badarin, Firas J; DiNicolantonio, James J; Lavie, Carl J; O'Keefe, James H

    2013-01-01

    Red yeast rice is an ancient Chinese food product that contains monacolins, chemical substances that are similar to statins in their mechanisms of action and lipid lowering properties. Several studies have found red yeast rice to be moderately effective at improving the lipid profile, particularly for lowering the low-density lipoprotein cholesterol levels. One large randomized controlled study from China found that red yeast rice significantly improved risk of major adverse cardiovascular events and overall survival in patients following myocardial infarction. Thus, red yeast rice is a potentially useful over-the-counter cholesterol-lowering agent. However, many red yeast rice formulations are non-standardized and unregulated food supplements, and there is a need for further research and regulation of production.

  13. Evolutionary History of Ascomyceteous Yeasts

    Energy Technology Data Exchange (ETDEWEB)

    Haridas, Sajeet; Riley, Robert; Salamov, Asaf; Goker, Markus; Klenk, Hans-Peter; Kurtzman, Cletus P.; Blackwell, Meredith; Grigoriev, Igor; Jeffries, Thomas W.

    2014-06-06

    Yeasts are important for many industrial and biotechnological processes and show remarkable diversity despite morphological similarities. We have sequenced the genomes of 16 ascomycete yeasts of taxonomic and industrial importance including members of Saccharomycotina and Taphrinomycotina. A comparison of these with several other previously published yeast genomes have added increased confidence to the phylogenetic positions of previously poorly placed species including Saitoella complicata, Babjeviella inositovora and Metschnikowia bicuspidata. Phylogenetic analysis also showed that yeasts with alternative nuclear codon usage where CUG encodes serine instead of leucine are monophyletic within the Saccharomycotina. Most of the yeasts have compact genomes with a large fraction of single exon genes with Lipomyces starkeyi and the previously published Pneumocystis jirovecii being notable exceptions. Intron analysis suggests that early diverging species have more introns. We also observed a large number of unclassified lineage specific non-simple repeats in these genomes.

  14. Bioprotective Role of Yeasts

    Science.gov (United States)

    Muccilli, Serena; Restuccia, Cristina

    2015-01-01

    The yeasts constitute a large group of microorganisms characterized by the ability to grow and survive in different and stressful conditions and then to colonize a wide range of environmental and human ecosystems. The competitive traits against other microorganisms have attracted increasing attention from scientists, who proposed their successful application as bioprotective agents in the agricultural, food and medical sectors. These antagonistic activities rely on the competition for nutrients, production and tolerance of high concentrations of ethanol, as well as the synthesis of a large class of antimicrobial compounds, known as killer toxins, which showed clearly a large spectrum of activity against food spoilage microorganisms, but also against plant, animal and human pathogens. This review describes the antimicrobial mechanisms involved in the antagonistic activity, their applications in the processed and unprocessed food sectors, as well as the future perspectives in the development of new bio-drugs, which may overcome the limitations connected to conventional antimicrobial and drug resistance. PMID:27682107

  15. Bioprotective Role of Yeasts

    Directory of Open Access Journals (Sweden)

    Serena Muccilli

    2015-10-01

    Full Text Available The yeasts constitute a large group of microorganisms characterized by the ability to grow and survive in different and stressful conditions and then to colonize a wide range of environmental and human ecosystems. The competitive traits against other microorganisms have attracted increasing attention from scientists, who proposed their successful application as bioprotective agents in the agricultural, food and medical sectors. These antagonistic activities rely on the competition for nutrients, production and tolerance of high concentrations of ethanol, as well as the synthesis of a large class of antimicrobial compounds, known as killer toxins, which showed clearly a large spectrum of activity against food spoilage microorganisms, but also against plant, animal and human pathogens. This review describes the antimicrobial mechanisms involved in the antagonistic activity, their applications in the processed and unprocessed food sectors, as well as the future perspectives in the development of new bio-drugs, which may overcome the limitations connected to conventional antimicrobial and drug resistance.

  16. Interaction Between Yeasts and Zinc

    Science.gov (United States)

    Nicola, Raffaele De; Walker, Graeme

    Zinc is an essential trace element in biological systems. For example, it acts as a cellular membrane stabiliser, plays a critical role in gene expression and genome modification and activates nearly 300 enzymes, including alcohol dehydrogenase. The present chapter will be focused on the influence of zinc on cell physiology of industrial yeast strains of Saccharomyces cerevisiae, with special regard to the uptake and subsequent utilisation of this metal. Zinc uptake by yeast is metabolism-dependent, with most of the available zinc translocated very quickly into the vacuole. At cell division, zinc is distributed from mother to daughter cells and this effectively lowers the individual cellular zinc concentration, which may become zinc depleted at the onset of the fermentation. Zinc influences yeast fermentative performance and examples will be provided relating to brewing and wine fermentations. Industrial yeasts are subjected to several stresses that may impair fermentation performance. Such stresses may also impact on yeast cell zinc homeostasis. This chapter will discuss the practical implications for the correct management of zinc bioavailability for yeast-based biotechnologies aimed at improving yeast growth, viability, fermentation performance and resistance to environmental stresses

  17. Lager Yeast Comes of Age

    Science.gov (United States)

    2014-01-01

    Alcoholic fermentations have accompanied human civilizations throughout our history. Lager yeasts have a several-century-long tradition of providing fresh beer with clean taste. The yeast strains used for lager beer fermentation have long been recognized as hybrids between two Saccharomyces species. We summarize the initial findings on this hybrid nature, the genomics/transcriptomics of lager yeasts, and established targets of strain improvements. Next-generation sequencing has provided fast access to yeast genomes. Its use in population genomics has uncovered many more hybridization events within Saccharomyces species, so that lager yeast hybrids are no longer the exception from the rule. These findings have led us to propose network evolution within Saccharomyces species. This “web of life” recognizes the ability of closely related species to exchange DNA and thus drain from a combined gene pool rather than be limited to a gene pool restricted by speciation. Within the domesticated lager yeasts, two groups, the Saaz and Frohberg groups, can be distinguished based on fermentation characteristics. Recent evidence suggests that these groups share an evolutionary history. We thus propose to refer to the Saaz group as Saccharomyces carlsbergensis and to the Frohberg group as Saccharomyces pastorianus based on their distinct genomes. New insight into the hybrid nature of lager yeast will provide novel directions for future strain improvement. PMID:25084862

  18. Using survival analysis of artificial and Real Brewer's sparrow (Spizella breweri breweri) nests to model site level and nest site factors associated with nest success in the South Okanagan region of Canada

    Science.gov (United States)

    Pam Krannitz Kym Welstead

    2005-01-01

    Predation is the predominant cause of nest failure for the Brewer's Sparrow (Spizella breweri breweri), a provincially red-listed shrub-steppe species that has experienced significant declines throughout most of its range. We monitored Brewer’s Sparrow nests and conducted an artificial nest experiment, in the South Okanagan Valley,...

  19. Extension of Yeast Chronological Lifespan by Methylamine

    NARCIS (Netherlands)

    Kumar, Sanjeev; Lefevre, Sophie D.; Veenhuis, Marten; van der Klei, Ida J.

    2012-01-01

    Background: Chronological aging of yeast cells is commonly used as a model for aging of human post-mitotic cells. The yeast Saccharomyces cerevisiae grown on glucose in the presence of ammonium sulphate is mainly used in yeast aging research. We have analyzed chronological aging of the yeast

  20. The Influence of Brewer’s Yeast Autolysate and Lactic Acid Bacteria on the Production of a Functional Food Additive Based on Beetroot Juice Fermentation

    Directory of Open Access Journals (Sweden)

    Josip Baras

    2004-01-01

    Full Text Available The importance of »functional foods« in the world is increasing, and the procedures for their production are under intense development. The goal of this paper is to optimise the production of a functional food additive based on beetroot juice (Beta vulgaris L. using brewer’s yeast autolysate. In order to improve the nutritive properties of the product and to preserve it, the possibility of beetroot juice fermentation using a Lactobacillus species has been investigated. Comparative investigations of three bacteria cultures (L. plantarum A112, L. acidophilus BGSJ15-3 and L. acidophilus NCDO1748 during fermentation in two media, beetroot juice and a mixture of beetroot juice with an autolysate of brewer´s yeast, have been performed. The poorest fermentative activity and growth in both substrates was observed using the L. acidophilus NCDO1748 culture. The two cultures demonstrated better fermentative activity in the mixture of tested substrates, while acidifying activity (production of lactic acid and a decrease in pH of the L. acidophilus BGSJ15-3 culture was considerably better than that of the L. plantarum A112 culture. L. plantarum A112 culture showed better growth than L. acidophilus BGSJ15-3. From the results obtained, it has been concluded that the L. plantarum A112 and L. acidophilus BGSJ15-3 can be successfully used for fermentation of the mixture of beetroot juice and brewer’s yeast autolysate in order to obtain a functional food additive.

  1. Red Yeast Rice: An Introduction

    Science.gov (United States)

    ... mg twice daily) in patients with previous statin intolerance . American Journal of Cardiology . 2010;105:198–204. ... to Avoid Red Yeast Rice Products Promoted on Internet as Treatments for High Cholesterol: Products Found to ...

  2. Biotechnical Microbiology, yeast and bacteria

    DEFF Research Database (Denmark)

    Villadsen, Ingrid Stampe

    1999-01-01

    This section contains the following single lecture notes: Eukaryotic Cell Biology. Kingdom Fungi. Cell Division. Meiosis and Recombination. Genetics of Yeast. Organisation of the Chromosome. Organization and genetics of the mitochondrial Geneme. Regulatio of Gene Expression. Intracellular Compart...

  3. Sexual differentiation in fission yeast

    DEFF Research Database (Denmark)

    Egel, R; Nielsen, O; Weilguny, D

    1990-01-01

    The regulation of sexual reproduction in yeast constitutes the highest level of differentiation observed in these unicellular organisms. The various ramifications of this system involve DNA rearrangement, transcriptional control, post-translational modification (such as protein phosphorylation) a...

  4. Mucositis Grades and Yeast Species

    OpenAIRE

    Ognjenović, Marina; Milatić, Katja; Parat, Katica; KOVAČIĆ, IVAN; Ježina Bušelić, Marina A.; Božić, Joško

    2013-01-01

    Surgically treated patients with oral, head and neck cancer commonly develop mucositis during additional irradiation therapy. Oral mucosa inflammation other than irradiation is mostly caused by Candida albicans, yeast of Candida genus. This study evaluated possible connection between grades of oral mucositis and oral yeast profile in irradiated patients before, during and after irradiation. In 25 examined patients mucosits grades »0« to »2« before irradiation with 20% positive smears and o...

  5. Biotechnological Applications of Dimorphic Yeasts

    Science.gov (United States)

    Doiphode, N.; Joshi, C.; Ghormade, V.; Deshpande, M. V.

    The dimorphic yeasts have the equilibrium between spherical growth (budding) and polarized (hyphal or pseudohyphal tip elongation) which can be triggered by change in the environmental conditions. The reversible growth phenomenon has made dimorphic yeasts as an useful model to understand fungal evolution and fungal differentiation, in general. In nature dimorphism is clearly evident in plant and animal fungal pathogens, which survive and most importantly proliferate in the respective hosts. However, number of organisms with no known pathogenic behaviour also show such a transition, which can be exploited for the technological applications due to their different biochemical make up under different morphologies. For instance, chitin and chitosan production using dimorphic Saccharomyces, Mucor, Rhizopus and Benjaminiella, oil degradation and biotransformation with yeast-form of Yarrowia species, bioremediation of organic pollutants, exopolysac-charide production by yeast-phase of Aureobasidium pullulans, to name a few. Myrothecium verrucaria can be used for seed dressing in its yeast form and it produces a mycolytic enzyme complex in its hyphal-form for the biocontrol of fungal pathogens, while Beauveria bassiana and other entomopathogens kill the insect pest by producing yeast- like cells in the insect body. The form-specific expression of protease, chitinase, lipase, ornithine decarboxylase, glutamate dehydrogenases, etc. make Benjaminiella poitrasii, Basidiobolus sp., and Mucor rouxii strains important in bioremediation, nanobiotechnology, fungal evolution and other areas.

  6. [Spectroscopic study of the structure and intramolecular mobility of yeast pyruvate decarboxylase].

    Science.gov (United States)

    Maskevich, S A; Maskevich, A A; Kivach, L N; Chernikevich, I P; Zabrodskaia, S V; Oparin, D A

    1993-12-01

    Steady-state and time-resolved fluorimetry were used to study the properties of holo- and apopyruvate decarboxylase (EC 4.1.1.1, PDC) from Brewer's yeast after interaction with substrate (pyruvate), cofactor (thiamine diphosphate, ThDP) and Mg2+ ions. The analysis of the enzyme's intrinsic fluorescence as well as of its complex with the probe 2-(p-toluidinylnaphthalene)-6-sulphonate (TNS) revealed that ThDP was found at the polar region of the PDC active sites, inducing a decrease in the mobility of the protein's nearest surroundings. The fluorescent probe had three different sites of binding to the protein apoform, two of which being located at the catalytic site and having different rotation freedom. The study of the PDC complex with thiochrome pyrophosphate, a ThDP structural analogue, pointed to the occurrence of a non-polar region of the enzyme active site for pyruvate absorption besides the polar region. The binding of pyruvate to the protein does not depend upon the cofactor's binding. On the basis of the fluorescent studies a model of the ThDP and pyruvate arrangement at the PDC active site is suggested.

  7. Red Yeast Rice

    Directory of Open Access Journals (Sweden)

    Thu Nguyen

    2017-03-01

    Full Text Available Red yeast rice (RYR, produced by the fermentation of the Monascus purpureus mold, has been used for a long time in Asian cuisine and traditional medicine. It consists of multiple bioactive substances, including monacolins, which potentially can be used as a nutraceutical. Monacolin K, which is chemically identical to lovastatin, has been recognized as responsible for the cholesterolreducing effect of this compound. While the European Food Safety Authority maintains that the use of monacolin K from RYR preparations of at least 10 mg can produce a normal blood cholesterol level, the United States Food and Drug Administration considers monacolin K, due to its similarity with lovastatin, an unapproved drug, and therefore marketing of products that label the monacolin content is prohibited. This mini-review summarizes the benefit of RYR in hyperlipidemia, maintains RYR use as a food, and addresses the importance of regulation regarding RYR and the need for clinical data and clear label information for consumers with reference to a toxin-free, nonaugmented, standardized amount of monacolins.

  8. Red Yeast Rice.

    Science.gov (United States)

    Nguyen, Thu; Karl, Mitchell; Santini, Antonello

    2017-03-01

    Red yeast rice (RYR), produced by the fermentation of the Monascus purpureus mold, has been used for a long time in Asian cuisine and traditional medicine. It consists of multiple bioactive substances, including monacolins, which potentially can be used as a nutraceutical. Monacolin K, which is chemically identical to lovastatin, has been recognized as responsible for the cholesterolreducing effect of this compound. While the European Food Safety Authority maintains that the use of monacolin K from RYR preparations of at least 10 mg can produce a normal blood cholesterol level, the United States Food and Drug Administration considers monacolin K, due to its similarity with lovastatin, an unapproved drug, and therefore marketing of products that label the monacolin content is prohibited. This mini-review summarizes the benefit of RYR in hyperlipidemia, maintains RYR use as a food, and addresses the importance of regulation regarding RYR and the need for clinical data and clear label information for consumers with reference to a toxin-free, nonaugmented, standardized amount of monacolins.

  9. Synthetic Yeast Cooperation

    Science.gov (United States)

    Shou, Wenying; Burton, Justin

    2010-03-01

    Cooperation is wide-spread and has been postulated to drive major transitions in evolution. However, Darwinian selection favors ``cheaters'' that consume benefits without paying a fair cost. How did cooperation evolve against the threat of cheaters? To investigate the evolutionary trajectories of cooperation, we created a genetically tractable system that can be observed as it evolves from inception. The system consists of two engineered yeast strains -- a red-fluorescent strain that requires adenine and releases lysine and a yellow-fluorescent strain that requires lysine and releases adenine. Cells that consume but not supply metabolites would be cheaters. From the properties of two cooperating strains, we calculated and experimentally verified the minimal initial cell densities required for the viability of the cooperative system in the absence of exogenously added adenine and lysine. Strikingly, evolved cooperative systems were viable at 100-fold lower initial cell densities than their ancestors. We are investigating the nature and diversity of pro-cooperation changes, the dynamics of cooperator-cheater cocultures, and the effects of spatial environment on cooperation and cheating.

  10. Advances in the representation of stratospheric transport by the Brewer-Dobson circulation by use of Lagrangian modelling with CLaMS

    Science.gov (United States)

    Ploeger, Felix; Konopka, Paul; Diallo, Mohamadou; Birner, Thomas; Hoppe, Charlotte; Müller, Rolf; Haenel, Florian; Stiller, Gabriele; Poshyvailo, Liubov; Garny, Hella; Dietmüller, Simone; Jöckel, Patrick; Engel, Andreas; Boenisch, Harald

    2017-04-01

    The global stratospheric Brewer-Dobson circulation (BDC) is expected to accelerate with rising Greenhouse gas concentrations, in turn changing the stratospheric trace gas composition and providing an important feedback via radiation on climate change. However, trends in the BDC are largely uncertain, with current climate model results disagreeing with existing observations of mean age of air, the average transit time for an air parcel since entering the stratosphere. We present advances in representing stratospheric trace gas transport caused by the Brewer-Dobson circulation by using the Chemical Lagrangian model of the Stratosphere (CLaMS), a global Lagrangian chemistry transport model with a physically-based parameterization of small-scale mixing. Mean age simulated with CLaMS driven by reanalysis meteorology agrees well with satellite and in-situ observations. Regarding the inter-annual and decadal changes, like increasing age in the Northern hemisphere and decreasing age in the Southern hemisphere during 2002-2012, the natural variability (e.g., QBO, ENSO, volcanic aerosols) is found to play a key role. Age of air spectra simulated with CLaMS provide further insights into the processes involved. Our analysis reveals a crucial effect of mixing on mean age and its decadal change pattern, suggesting that differences between climate models and observations likely involve differences in the effect of mixing. This progress in modelling stratospheric transport has recently been transferred to climate modelling by coupling the Lagrangian transport scheme CLaMS into the global atmosphere-chemistry model EMAC. First results show improvements of stratospheric transport compared to the standard flux-form semi-Lagrangian transport scheme. These improvements are found particularly in regions of strong transport barriers like the polar vortex, with Lagrangian CLaMS transport resulting in a stronger and more realistic transport barrier.

  11. Yeast Genetics and Biotechnological Applications

    Science.gov (United States)

    Mishra, Saroj; Baranwal, Richa

    Yeast can be recognized as one of the very important groups of microorganisms on account of its extensive use in the fermentation industry and as a basic eukaryotic model cellular system. The yeast Saccharomyces cerevisiae has been extensively used to elucidate the genetics and regulation of several key functions in the cell such as cell mating, electron transport chain, protein trafficking, cell cycle events and others. Even before the genome sequence of the yeast was out, the structural organization and function of several of its genes was known. With the availability of the origin of replication from the 2 μm plasmid and the development of transformation system, it became the host of choice for expression of a number of important proteins. A large number of episomal and integrative shuttle vectors are available for expression of mammalian proteins. The latest developments in genomics and micro-array technology have allowed investigations of individual gene function by site-specific deletion method. The application of metabolic profiling has also assisted in understanding the cellular network operating in this yeast. This chapter is aimed at reviewing the use of this system as an experimental tool for conducting classical genetics. Various vector systems available, foreign genes expressed and the limitations as a host will be discussed. Finally, the use of various yeast enzymes in biotechnology sector will be reviewed.

  12. Emulsifying activity of hydrocarbonoclastic marine yeasts

    Digital Repository Service at National Institute of Oceanography (India)

    Gupta, R.

    Marine yeast growth on four petroleum hydrocarbons induced the production of extracellular emulsifying agents (biosurfactants). Out of the 17 marine yeast isolates tested, 7 isolates, i.e., Candida parapsilosis, C. cantarelli, C. membranae...

  13. Chromatin and Transcription in Yeast

    Science.gov (United States)

    Rando, Oliver J.; Winston, Fred

    2012-01-01

    Understanding the mechanisms by which chromatin structure controls eukaryotic transcription has been an intense area of investigation for the past 25 years. Many of the key discoveries that created the foundation for this field came from studies of Saccharomyces cerevisiae, including the discovery of the role of chromatin in transcriptional silencing, as well as the discovery of chromatin-remodeling factors and histone modification activities. Since that time, studies in yeast have continued to contribute in leading ways. This review article summarizes the large body of yeast studies in this field. PMID:22345607

  14. Characteristics of fermentation yeast isolated from traditional ...

    African Journals Online (AJOL)

    A relatively higher amount of propan-1-ol (43 mg/l) was found in the honey wine than in those made with wine yeast W4 and sake yeast K7. The aroma characteristics of honey wine made with yeast ET99 were acceptable, as determined by organoleptic tests, and were found to be applicable to ethanol fermentation.

  15. 21 CFR 73.355 - Phaffia yeast.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 1 2010-04-01 2010-04-01 false Phaffia yeast. 73.355 Section 73.355 Food and... ADDITIVES EXEMPT FROM CERTIFICATION Foods § 73.355 Phaffia yeast. (a) Identity. (1) The color additive phaffia yeast consists of the killed, dried cells of a nonpathogenic and nontoxicogenic strain of the...

  16. Yeast genomics on food flavours

    NARCIS (Netherlands)

    Schoondermark-Stolk, Sung Ah

    2005-01-01

    The appearance and concentration of the fusel alcohol 3-methyl-1-butanol is important for the flavour of fermented foods. 3-Methyl-1-butanol is formed by yeast during the conversion of L-leucine. Identification of the enzymes and genes involved in the formation of 3-methyl-1-butanol is a major

  17. Nucleotide excision repair in yeast

    NARCIS (Netherlands)

    Eijk, Patrick van

    2012-01-01

    Nucleotide Excision Repair (NER) is a conserved DNA repair pathway capable of removing a broad spectrum of DNA damage. In human cells a defect in NER leads to the disorder Xeroderma pigmentosum (XP). The yeast Saccharomyces cerevisiae is an excellent model organism to study the mechanism of NER. The

  18. Surplus yeast tank failing catastrophically

    DEFF Research Database (Denmark)

    Hedlund, Frank Huess

    2016-01-01

    GOOD REASON FOR CAUTION I A large surplus yeast tank shot into the air leaving the floor plate and the contents behind. Although not designed for overpressure, the tank was kept at “very slight overpressure” to suppress nuisance foaming. The brewery was unaware of the hazards of compressed air...

  19. Genome-wide array-CGH analysis reveals YRF1 gene copy number variation that modulates genetic stability in distillery yeasts.

    Science.gov (United States)

    Deregowska, Anna; Skoneczny, Marek; Adamczyk, Jagoda; Kwiatkowska, Aleksandra; Rawska, Ewa; Skoneczna, Adrianna; Lewinska, Anna; Wnuk, Maciej

    2015-10-13

    Industrial yeasts, economically important microorganisms, are widely used in diverse biotechnological processes including brewing, winemaking and distilling. In contrast to a well-established genome of brewer's and wine yeast strains, the comprehensive evaluation of genomic features of distillery strains is lacking. In the present study, twenty two distillery yeast strains were subjected to electrophoretic karyotyping and array-based comparative genomic hybridization (array-CGH). The strains analyzed were assigned to the Saccharomyces sensu stricto complex and grouped into four species categories: S. bayanus, S. paradoxus, S. cerevisiae and S. kudriavzevii. The genomic diversity was mainly revealed within subtelomeric regions and the losses and/or gains of fragments of chromosomes I, III, VI and IX were the most frequently observed. Statistically significant differences in the gene copy number were documented in six functional gene categories: 1) telomere maintenance via recombination, DNA helicase activity or DNA binding, 2) maltose metabolism process, glucose transmembrane transporter activity; 3) asparagine catabolism, cellular response to nitrogen starvation, localized in cell wall-bounded periplasmic space, 4) siderophore transport, 5) response to copper ion, cadmium ion binding and 6) L-iditol 2- dehydrogenase activity. The losses of YRF1 genes (Y' element ATP-dependent helicase) were accompanied by decreased level of Y' sequences and an increase in DNA double and single strand breaks, and oxidative DNA damage in the S. paradoxus group compared to the S. bayanus group. We postulate that naturally occurring diversity in the YRF1 gene copy number may promote genetic stability in the S. bayanus group of distillery yeast strains.

  20. Yeasts in an industrial malting ecosystem.

    Science.gov (United States)

    Laitila, A; Wilhelmson, A; Kotaviita, E; Olkku, J; Home, S; Juvonen, R

    2006-11-01

    The malting ecosystem consists of two components: the germinating cereal grains and the complex microbial community. Yeasts and yeast-like fungi are an important part of this ecosystem, but the composition and the effects of this microbial group have been largely unknown. In this study we surveyed the development of yeasts and yeast-like fungi in four industrial scale malting processes. A total of 136 malting process samples were collected and examined for the presence of yeasts growing at 15, 25 and 37 degrees C. More than 700 colonies were isolated and characterized. The isolates were discriminated by PCR-fingerprinting with microsatellite primer (M13). Yeasts representing different fingerprint types were identified by sequence analysis of the D1/D2 domain of the 26S rRNA gene. Furthermore, identified yeasts were screened for the production of alpha-amylase, beta-glucanase, cellulase and xylanase. A numerous and diverse yeast community consisting of both ascomycetous (25) and basidiomycetous (18) species was detected in the various stages of the malting process. The most frequently isolated ascomycetous yeasts belonged to the genera Candida, Clavispora, Galactomyces, Hanseniaspora, Issatchenkia, Pichia, Saccharomyces and Williopsis and the basidiomycetous yeasts to Bulleromyces, Filobasidium, Cryptococcus, Rhodotorula, Sporobolomyces and Trichosporon. In addition, two ascomycetous yeast-like fungi (black yeasts) belonging to the genera Aureobasidium and Exophiala were commonly detected. Yeasts and yeast-like fungi produced extracellular hydrolytic enzymes with a potentially positive contribution to the malt enzyme spectrum. Knowledge of the microbial diversity provides a basis for microflora management and understanding of the role of microbes in the cereal germination process.

  1. Effects of urban agglomeration on surface-UV doses: a comparison of Brewer measurements in Warsaw and Belsk, Poland, for the period 2013-2015

    Science.gov (United States)

    Czerwińska, Agnieszka E.; Krzyścin, Janusz W.; Jarosławski, Janusz; Posyniak, Michał

    2016-11-01

    Specific aerosols and cloud properties over large urban regions seem to generate an island, similar to the well-known urban heat island, leading to lower ultraviolet (UV) radiation intensity compared to the surrounding less polluted areas, thus creating a shield against excessive human exposure to UV radiation. The present study focuses on differences between erythemal and UVA (324 nm) doses measured by the Brewer spectrophotometers in Warsaw (52.3° N, 21.0° E) and Belsk (51.8° N, 20.8° E). The latter is a rural region located about 60 km south-west of the city. Ratios between erythemal and UVA partly daily doses, obtained during all-sky and cloudless-sky conditions for the period May 2013-December 2015, were analysed to infer a specific cloud and aerosol forcing on the surface UV doses over Warsaw. Radiative model simulations were carried out to find sources of the observed differences between the sites. It was found that Warsaw urban agglomeration induced 8 and 6 % attenuation of the erythemal and UVA doses respectively. This is mostly due to the lower sun elevation in Warsaw during the near-noon measurements and the larger optical depth of the city aerosols and increased cloudiness. It could be hypothesised that the expected stronger absorption of the solar UV radiation by urban aerosols is compensated for here by a higher surface reflectivity over the city.

  2. Valorization of Brewer's spent grain to prebiotic oligosaccharide: production, xylanase catalyzed hydrolysis, in-vitro evaluation with probiotic strains and in a batch human fecal fermentation model.

    Science.gov (United States)

    Sajib, Mursalin; Falck, Peter; Sardari, Roya R R; Mathew, Sindhu; Grey, Carl; Karlsson, Eva Nordberg; Adlercreutz, Patrick

    2018-01-11

    Brewer's spent grain (BSG) accounts for around 85% of the solid by-products from beer production. BSG was first extracted to obtain water-soluble arabinoxylan (AX). Using subsequent alkali extraction (0.5 M KOH) it was possible to dissolve additional AX. In total, about 57% of the AX in BSG was extracted with the purity of 45-55%. After comparison of nine xylanases, Pentopan mono BG, a GH11 enzyme, was selected for hydrolysis of the extracts to oligosaccharides with minimal formation of monosaccharides. Growth of Bifidobacterium adolescentis (ATCC 15703) was promoted by the enzymatic hydrolysis to arabinoxylooligosaccharides, while Lactobacillus brevis (DSMZ 1264) utilized only unsubstituted xylooligosaccharides. Furthermore, utilization of the hydrolysates by human gut microbiota was also assessed in a batch human fecal fermentation model. Results revealed that the rates of fermentation of the BSG hydrolysates by human gut microbiota were similar to that of commercial prebiotic fructooligosaccharides, while inulin was fermented at a slower rate. In summary, a sustainable process to valorize BSG to functional food ingredients has been proposed. Copyright © 2018. Published by Elsevier B.V.

  3. Optimization of some processing parameters and quality attributes of fried snacks from blends of wheat flour and brewers' spent cassava flour.

    Science.gov (United States)

    Omidiran, Adebukola T; Sobukola, Olajide P; Sanni, Ajoke; Adebowale, Abdul-Rasaq A; Obadina, Olusegun A; Sanni, Lateef O; Tomlins, Keith; Wolfgang, Tosch

    2016-01-01

    The effect of some processing parameters (frying temperature [140-160°C], frying time [2-4 min], level of brewers' spent cassava flour (BSCF) [20-40%], and thickness [2-4 mm]) on some quality attributes of wheat-BSCF fried snack was investigated. Response surface methodology based on Box-Behnken design was used to optimize the effect of process parameters on product quality. Sensory evaluation of the optimized sample to determine its level of acceptability was carried out as well as the comparison with fried snack from 100% wheat flour. Increasing temperature had significant (P texture. Based on the desirability (0.771) concept, a frying temperature of 140 °C, frying time of 4 min, 32% level of BSCF, and 2 mm thickness was obtained as the optimized conditions. Sensory analyses showed that the optimized sample was preferred in terms of texture and its oiliness to fried snack prepared from 100% wheat flour, but, the aroma, taste and appearance of the wheat snack were preferred.

  4. Discarded oranges and brewer's spent grains as promoting ingredients for microbial growth by submerged and solid state fermentation of agro-industrial waste mixtures.

    Science.gov (United States)

    Aggelopoulos, Theodoros; Bekatorou, Argyro; Pandey, Ashok; Kanellaki, Maria; Koutinas, Athanasios A

    2013-08-01

    The exploitation of various agro-industrial wastes for microbial cell mass production of Kluyveromyces marxianus, kefir, and Saccharomyces cerevisiae is reported in the present investigation. Specifically, the promotional effect of whole orange pulp on cell growth in mixtures consisting of cheese whey, molasses, and potato pulp in submerged fermentation processes was examined. A 2- to 3-fold increase of cell mass was observed in the presence of orange pulp. Likewise, the promotional effect of brewer's spent grains on cell growth in solid state fermentation of mixtures of whey, molasses, potato pulp, malt spent rootlets, and orange pulp was examined. The cell mass was increased by 3-fold for K. marxianus and 2-fold for S. cerevisiae in the presence of these substrates, proving their suitability for single-cell protein production without the need for extra nutrients. Cell growth kinetics were also studied by measurements of cell counts at various time intervals at different concentrations of added orange pulp. The protein content of the fermented substrates was increased substantially, indicating potential use of mixed agro-industrial wastes of negligible cost, as protein-enriched livestock feed, achieving at the same time creation of added value and waste minimization.

  5. Combinatorial pathway assembly in yeast

    Directory of Open Access Journals (Sweden)

    Khalil Essani

    2015-10-01

    Full Text Available With the emergence of synthetic biology and the vast knowledge about individual biocatalytic reactions, the challenge nowadays is to implement whole natural or synthetic pathways into microorganisms. For this purpose balanced enzyme activities throughout the pathway need to be achieved in addition to simple functional gene expression to avoid bottlenecks and to obtain high titers of the desired product. As the optimization of pathways in a specific biological context is often hard to achieve by rational design, combinatorial approaches have been developed to address this issue. Here, current strategies and proof of concepts for combinatorial pathway assembly in yeasts are reviewed. By exploiting its ability to join multiple DNA fragments in a very efficient and easy manner, the yeast Saccharomyces cerevisiae does not only constitute an attractive host for heterologous pathway expression, but also for assembling pathways by recombination in vivo.

  6. Yeast Isolation for Bioethanol Production

    Directory of Open Access Journals (Sweden)

    EKA RURIANI

    2012-09-01

    Full Text Available We have isolated 12 yeast isolates from five different rotten fruits by using a yeast glucose chloramphenicol agar (YGCA medium supplemented with tetracycline. From pre-screening assay, four isolates exhibited higher substrate (glucose-xylose consumption efficiency in the reaction tube fermentation compared to Saccharomyces cerevisiae dan Saccharomyces ellipsoids as the reference strains. Based on the fermentation process in gooseneck flasks, we observed that two isolates (K and SB showed high fermentation efficiency both in sole glucose and mixed glucose-xylose substrate. Moreover, isolates K and SB produced relatively identical level of ethanol concentration compared to the reference strains. Isolates H and MP could only produce high levels of ethanol in glucose fermentation, while only half of that amount of ethanol was detected in glucose-xylose fermentation. Isolate K and SB were identified as Pichia kudriavzeevii (100% based on large sub unit (LSU ribosomal DNA D1/D2 region.

  7. Yeast mixture of liquid beer and cassava pulp with rice straw for the growth of dairy heifers.

    Science.gov (United States)

    Kamphayae, Sukanya; Kumagai, Hajime; Butcha, Patima; Ritruechai, Viroj; Udchachon, Supachai

    2017-03-01

    This study was conducted to determine the effects of mixtures of liquid brewer's yeast (LBY) and cassava pulp (CVP) with rice straw (RS) on feed intake, digestibility, rumen fermentation, and growth of dairy heifers. Sixteen Holstein crossbred heifers (13.8 ± 1.6 months old, 210 ± 23 kg body weight (BW)) were randomly allocated to four feeding treatments with four replications, which were 0:0:100 (RS), 0:70:30 (0%LBY), 20:50:30 (20%LBY), and 50:20:30 (50%LBY), respectively, for LBY/CVP/RS on a fresh matter basis. The heifers were offered conventional concentrate at 1.5% initial body weight daily and fed the treatment diets ad libitum. Average daily gain and feed intake were not significantly different among the treatments. The heifers fed 50%LBY had the highest crude protein (CP) intake and DM, OM, and CP digestibility (P < 0.05). The ruminal pH did not differ significantly among treatments, while NH3-N was the highest (P < 0.05) in 50%LBY. Total volatile fatty acid (VFA) concentrations and the molar proportion of each VFA were not significantly different among the treatments. Blood urea nitrogen concentrations of 50%LBY were the highest among the treatments (P < 0.05). The results indicated that 50%LBY improved CP digestibility.

  8. Yeasts colonizing the leaf surfaces.

    Science.gov (United States)

    Sláviková, Elena; Vadkertiová, Renata; Vránová, Dana

    2007-08-01

    The yeasts were isolated from the leaf surfaces of ten species of trees. The study site was a forest park (Zelezná Studnicka) of the Small Carpathians mountain range. One hundred and thirty seven yeast strains belonging to 13 genera were isolated from 320 samples of leaves and needles. Seventeen yeast species were isolated, but only seven occurred regularly: Aureobasidium pullulans, Cryptococcus laurentii, Pichia anomala, Metschnikowia pulcherrima, Saccharomyces sp., Lachancea thermotolerans, and Rhodotorula glutinis. The remaining species were isolated from the leaves and needles of three or less tree species. A. pullulans, Cr. laurentii, and P. anomala were the most frequently found species and they occurred on leaves and needles of all ten tree species. Saccharomyces sp. occurred in leaf samples collected from eight kinds of trees. M. pulcherrima and L. thermotolerans were found in samples collected from six species of trees. Both these species occurred almost always on the leaves of deciduous trees. Rh. glutinis was the most frequently isolated carotenoids producing species. We have found out that the ascomycetous and basidiomycetous species were present in the leaf samples in approximately equal frequency, contrary to the soil samples taken from this forest park, where the ascomycetous species were found rarely.

  9. Yeast: A new oil producer?

    Directory of Open Access Journals (Sweden)

    Beopoulos Athanasios

    2012-01-01

    Full Text Available The increasing demand of plant oils or animal fat for biodiesel and specific lipid derivatives for the oleochemical field (such as lubricants, adhesives or plastics have created price imbalance in both the alimentary and energy field. Moreover, the lack of non-edible oil feedstock has given rise to concerns on land-use practices and on oil production strategies. Recently, much attention has been paid to the exploitation of microbial oils. Most of them present lipid profiles similar in type and composition to plants and could therefore have many advantages as are no competitive with food, have short process cycles and their cultivation is independent of climate factors. Among microorganisms, yeasts seem to be very promising as they can be easily genetically enhanced, are suitable for large-scale fermentation and are devoid of endotoxins. This review will focus on the recent understanding of yeasts lipid metabolism, the succeeding genetic engineering of the lipid pathways and the recent developments on fermentation techniques that pointed out yeasts as promising alternative producers for oil or plastic.

  10. Yeasts Diversity in Fermented Foods and Beverages

    Science.gov (United States)

    Tamang, Jyoti Prakash; Fleet, Graham H.

    People across the world have learnt to culture and use the essential microorganisms for production of fermented foods and alcoholic beverages. A fermented food is produced either spontaneously or by adding mixed/pure starter culture(s). Yeasts are among the essential functional microorganisms encountered in many fermented foods, and are commercially used in production of baker's yeast, breads, wine, beer, cheese, etc. In Asia, moulds are predominant followed by amylolytic and alcohol-producing yeasts in the fermentation processes, whereas in Africa, Europe, Australia and America, fermented products are prepared exclusively using bacteria or bacteria-yeasts mixed cultures. This chapter would focus on the varieties of fermented foods and alcoholic beverages produced by yeasts, their microbiology and role in food fermentation, widely used commercial starters (pilot production, molecular aspects), production technology of some common commercial fermented foods and alcoholic beverages, toxicity and food safety using yeasts cultures and socio-economy

  11. Yeast Interacting Proteins Database: YEL005C, YGL079W [Yeast Interacting Proteins Database

    Lifescience Database Archive (English)

    Full Text Available endosome; identified as a transcriptional activator in a high-throughput yeast one-hybrid assay Rows with th...protein localizes to the endosome; identified as a transcriptional activator in a high-throughput yeast one-

  12. Revaluation of Waste Yeast from Beer Production

    OpenAIRE

    Nicoleta Suruceanu; Sonia Socaci; Teodora Coldea; Elena Mudura

    2013-01-01

    Brewing yeast is an important waste product from beer production. The valorification of slurry yeast mainly consists of separation of vitamins and important nitrogen compounds. The hops compounds, one of the most important raw materials in beer technology are removed beforehand valorification. The prenylflavonoids compounds from hops are important bioactive compounds that can be revaluation with proper technology. Revaluation of prenylflavonoids from waste yeast into dietary supplement, ident...

  13. Did Gause Have a Yeast Infection?

    Science.gov (United States)

    Pritchard, Jonathon O; Porter, Alice H M; Montagnes, David J S

    2016-09-01

    We planned to develop predator-prey models using Paramecium and yeast, but they have not been empirically examined since work by Gause in the 1930s. Therefore, we evaluated if Paramecium aurelia ingests and grows on eight yeasts. Recognising that it ingested yeasts but could not grow, we assessed if it might grow on other yeasts, by empirically parameterising a predator-prey model that relies on ingestion, not growth. Simulations were compared to P. aurelia-yeast time-series data, from Gause. We hypothesised that if the model simulated predator-prey dynamics that mimicked the original data, then possibly P. aurelia could grow on yeast; simulations did not mimic the original data. Reviewing works by Gause exposed two issues: experiments were undoubtedly contaminated with bacteria, allowing growth on bacteria, not yeast; and the population cycle data cannot be considered a self-sustaining time series, as they were manipulated by adding yeast and ciliates. We conclude that past and future work should not rely on this system, for either empirical or theoretical evaluations. Finally, although we show that P. aurelia, P. caudatum, Euplotes patella, and Blepharisma sp. cannot grow on yeast, Tetrahymena pyriformis and Colpidium striatum can; these may provide models to explore predator-prey dynamics. © 2016 The Author(s) Journal of Eukaryotic Microbiology © 2016 International Society of Protistologists.

  14. Evaluation of Automated Yeast Identification System

    Science.gov (United States)

    McGinnis, M. R.

    1996-01-01

    One hundred and nine teleomorphic and anamorphic yeast isolates representing approximately 30 taxa were used to evaluate the accuracy of the Biolog yeast identification system. Isolates derived from nomenclatural types, environmental, and clinica isolates of known identity were tested in the Biolog system. Of the isolates tested, 81 were in the Biolog database. The system correctly identified 40, incorrectly identified 29, and was unable to identify 12. Of the 28 isolates not in the database, 18 were given names, whereas 10 were not. The Biolog yeast identification system is inadequate for the identification of yeasts originating from the environment during space program activities.

  15. Comparison of wet brewers' grains or dried distillers' grains as supplements to conserved bermudagrass forage as winter feeding options for beef cows.

    Science.gov (United States)

    Thomas, M V; Hersom, M J; Thrift, T A; Yelich, J V

    2017-01-01

    The objective of this study was to examine the use of 2 byproduct supplements and conserved warm-season forage as winter feeding options for primiparous beef cows. Gestating Angus ( = 48) and Brangus ( = 24) 2-yr-old cows were stratified by BW and breed to 1 of 12 pens. Pens were randomly assigned 1 of 2 supplements, wet brewers' grains (WBG) or dried distillers' grains (DDG). Coastal bermudagrass hay or round bale silage (RBS) was fed free choice (6 pens each) and cows received WBG or DDG supplements at a daily rate of 0.05% BW (DM basis) prorated for feeding 3 d/wk. Total BW and BCS changes did not differ ( = 0.65 and = 0.93, respectively) between DDG- and WBG-supplemented cows. Total amount of forage DM offered and mean calculated daily forage DM offered did not differ ( = 0.59 and = 0.20, respectively) between supplement treatments. Estimated daily mean and total supplement DM offered was greater ( forage sources were used in an unbalanced 6 × 4 design to measure intake, digestibility, and rumen parameters in ruminally fistulated steers. Supplement did not affect forage DMI of hay ( = 0.31) or RBS ( = 0.63). Total DMI was not different ( = 0.37 and = 0.73) for hay-based and RBS-based diets, respectively. Total tract digestibility tended to be greater ( = 0.06) for DDG than for WBG in hay diets but was not different ( = 0.76) for RBS diets. Daily mean ruminal pH was greater ( = 0.03) for WBG than for DDG when supplemented to hay-based diets. In RBS diets, a supplement × hour interaction ( = 0.05) existed for ruminal pH. Daily mean ruminal ammonia N concentration was greater ( forage. High-moisture forage sources can be coupled with high-moisture byproduct supplements.

  16. Fatal gestational trophoblastic neoplasia: An analysis of treatment failures at the Brewer Trophoblastic Disease Center from 1979-2012 compared to 1962-1978.

    Science.gov (United States)

    Neubauer, Nikki L; Strohl, Anna E; Schink, Julian C; Lurain, John R

    2015-08-01

    To determine clinical factors that contributed to death from gestational trophoblastic neoplasia (GTN) at the Brewer Trophoblastic Disease Center from 1979-2012 compared to 1962-1978. Nineteen women who died of GTN from 1979-2012 were retrospectively identified and compared to 45 women previously reported on who died of GTN from 1962-1978. Clinical factors analyzed included demographics, pretreatment human chorionic gonadotropin (hCG) level, duration of disease, antecedent pregnancy, number and sites of metastases, FIGO stage and score, treatment, and cause of death. Death from GTN occurred in 19 (4%) of 483 patients treated from 1979-2012 compared to 45 (11%) of 396 patients treated from 1962-1978 (P100,000 mIU/mL, time from pregnancy event to treatment >4 months, nonmolar antecedent pregnancy and use of surgery to control metastatic disease were similar between the two treatment eras. Patients in the recent series were more likely to have presented with FIGO IV disease or brain metastasis, been initially treated with multiagent chemotherapy, and received treatment before referral to our center compared to the earlier series. The most common causes of death from 1979-2012 and 1962-1978 were hemorrhage from one or more metastatic sites (11% vs. 42%), respiratory failure (37% vs. 31%), and multiorgan failure due to widespread chemoresistant disease (42% vs. 8%), respectively. Our overall survival rate in patients with gestational trophoblastic neoplasia improved from 89% in 1962-1978 to 96% in 1979-2012. More patients treated between 1979-2012 died from widespread chemoresistant disease rather than hemorrhagic complications. Copyright © 2015 Elsevier Inc. All rights reserved.

  17. High Precision, Absolute Total Column Ozone Measurements from the Pandora Spectrometer System: Comparisons with Data from a Brewer Double Monochromator and Aura OMI

    Science.gov (United States)

    Tzortziou, Maria A.; Herman, Jay R.; Cede, Alexander; Abuhassan, Nader

    2012-01-01

    We present new, high precision, high temporal resolution measurements of total column ozone (TCO) amounts derived from ground-based direct-sun irradiance measurements using our recently deployed Pandora single-grating spectrometers. Pandora's small size and portability allow deployment at multiple sites within an urban air-shed and development of a ground-based monitoring network for studying small-scale atmospheric dynamics, spatial heterogeneities in trace gas distribution, local pollution conditions, photochemical processes and interdependencies of ozone and its major precursors. Results are shown for four mid- to high-latitude sites where different Pandora instruments were used. Comparisons with a well calibrated double-grating Brewer spectrometer over a period of more than a year in Greenbelt MD showed excellent agreement and a small bias of approximately 2 DU (or, 0.6%). This was constant with slant column ozone amount over the full range of observed solar zenith angles (15-80), indicating adequate Pandora stray light correction. A small (1-2%) seasonal difference was found, consistent with sensitivity studies showing that the Pandora spectral fitting TCO retrieval has a temperature dependence of 1% per 3K, with an underestimation in temperature (e.g., during summer) resulting in an underestimation of TCO. Pandora agreed well with Aura-OMI (Ozone Measuring Instrument) satellite data, with average residuals of <1% at the different sites when the OMI view was within 50 km from the Pandora location and OMI-measured cloud fraction was <0.2. The frequent and continuous measurements by Pandora revealed significant short-term (hourly) temporal changes in TCO, not possible to capture by sun-synchronous satellites, such as OMI, alone.

  18. Effects of urban agglomeration on surface-UV doses: a comparison of Brewer measurements in Warsaw and Belsk, Poland, for the period 2013–2015

    Directory of Open Access Journals (Sweden)

    A. E. Czerwińska

    2016-11-01

    Full Text Available Specific aerosols and cloud properties over large urban regions seem to generate an island, similar to the well-known urban heat island, leading to lower ultraviolet (UV radiation intensity compared to the surrounding less polluted areas, thus creating a shield against excessive human exposure to UV radiation. The present study focuses on differences between erythemal and UVA (324 nm doses measured by the Brewer spectrophotometers in Warsaw (52.3° N, 21.0° E and Belsk (51.8° N, 20.8° E. The latter is a rural region located about 60 km south-west of the city. Ratios between erythemal and UVA partly daily doses, obtained during all-sky and cloudless-sky conditions for the period May 2013–December 2015, were analysed to infer a specific cloud and aerosol forcing on the surface UV doses over Warsaw. Radiative model simulations were carried out to find sources of the observed differences between the sites. It was found that Warsaw urban agglomeration induced 8 and 6 % attenuation of the erythemal and UVA doses respectively. This is mostly due to the lower sun elevation in Warsaw during the near-noon measurements and the larger optical depth of the city aerosols and increased cloudiness. It could be hypothesised that the expected stronger absorption of the solar UV radiation by urban aerosols is compensated for here by a higher surface reflectivity over the city.

  19. Yeast Infection Test: MedlinePlus Lab Test Information

    Science.gov (United States)

    ... this page: https://medlineplus.gov/labtests/yeastinfectiontest.html Yeast Infection Test To use the sharing features on this page, please enable JavaScript. What is a Yeast Test? Yeast is a type of fungus that ...

  20. Cell size control in yeast.

    Science.gov (United States)

    Turner, Jonathan J; Ewald, Jennifer C; Skotheim, Jan M

    2012-05-08

    Cell size is an important adaptive trait that influences nearly all aspects of cellular physiology. Despite extensive characterization of the cell-cycle regulatory network, the molecular mechanisms coupling cell growth to division, and thereby controlling cell size, have remained elusive. Recent work in yeast has reinvigorated the size control field and suggested provocative mechanisms for the distinct functions of setting and sensing cell size. Further examination of size-sensing models based on spatial gradients and molecular titration, coupled with elucidation of the pathways responsible for nutrient-modulated target size, may reveal the fundamental principles of eukaryotic cell size control. Copyright © 2012 Elsevier Ltd. All rights reserved.

  1. Glucose-6-phosphate dehydrogenase from brewers' yeast. The effects of pH and temperature on the steady-state kinetic parameters of the two-chain protein species.

    Science.gov (United States)

    Kuby, S A; Roy, R N

    1976-05-04

    A systematic study has been made of the pH- and temperature-dependency of the steady-state kinetic parameters of the stabilized two-subunit enzyme species of glucose-6-phosphate dehydrogenase, in the absence of superimposed association-dissociation reactions. The Vmax(app) data obtained in several buffers between pH 5 and 10 and at 18-32 degrees C lead to the postulate that at least two sets of protonic equilibria may govern the catalysis (one near pH 5.7 AT 25 DEGREES C and another near pH 9.2); furthermore, two pathways for product formation (i.e., two Vmax's) appear to be required to explain the biphasic nature of the log Vmax(app) vs. pH curves, with Vmax(basic) greater than Vmax(acidic + neutral). Of the several buffers explored, either a uniform degree of interaction or a minimal degree of buffer species interaction could be assessed from the enthalpy changes associated with the derived values for ionization constants attributed to the protonic equilibria in the enzyme-substrates ternary complexes for the case of Tris-acetate-EDTA buffers, at constant ionic strength. With the selection of this buffer at 0.1 (T/2) and at 25 and 32 degrees C, a self-consistent kinetic mechanism has emerged which allows for the random binding of the two fully ionized substrates to the enzyme via two major pathways, and product formation by both E-A--B- and HE-A--B-. As before (Kuby et al. Arch. Biochem, Biophys. 165, 153-178, 1974), a quasi-equilibrium is presumed, with rate-limiting steps (k + 5 and k + 5') at the interconversion of the ternary complexes. Values for the two sets of protonic equilibria defined by this mechanism (viz., pKk, pKH2 for the first ionizations, and pKk', pKH' for the second) could then be estimated. From their numerical values (e.g., at 25 degrees C: pKK = 5.7 PKH2 = 5.2; and pKK' = 9.1, PKH' = 8.2) and from the values for delta H degrees ioniz (e.g., delta H degrees pKK APPROXIMATELY 5.1 KCAL/MOL; DELTA H degrees pKK' APPROXIMATELY 11 KCAL/MOL), A POSTULATE IS PRESENTED WHICH ATTRIBUTES THESE Acid dissociation constants to an imidazole and epsilon-amino group, respectively.

  2. The wine and beer yeast Dekkera bruxellensis.

    Science.gov (United States)

    Schifferdecker, Anna Judith; Dashko, Sofia; Ishchuk, Olena P; Piškur, Jure

    2014-09-01

    Recently, the non-conventional yeast Dekkera bruxellensis has been gaining more and more attention in the food industry and academic research. This yeast species is a distant relative of Saccharomyces cerevisiae and is especially known for two important characteristics: on the one hand, it is considered to be one of the main spoilage organisms in the wine and bioethanol industry; on the other hand, it is 'indispensable' as a contributor to the flavour profile of Belgium lambic and gueuze beers. Additionally, it adds to the characteristic aromatic properties of some red wines. Recently this yeast has also become a model for the study of yeast evolution. In this review we focus on the recently developed molecular and genetic tools, such as complete genome sequencing and transformation, to study and manipulate this yeast. We also focus on the areas that are particularly well explored in this yeast, such as the synthesis of off-flavours, yeast detection methods, carbon metabolism and evolutionary history. © 2014 The Authors. Yeast published by John Wiley & Sons, Ltd.

  3. Comet assay on tetraploid yeast cells

    DEFF Research Database (Denmark)

    Rank, Jette; Syberg, Kristian; Jensen, Klara

    2009-01-01

    . Analytical problems that arose due to the small amount of DNA in the yeast nuclei in haploid and diploid cells, which contain 13 Mbp and 26 Mbp DNA per cell, respectively, were solved by using tetraploid yeast cells (52 Mbp) instead. DNA damage was shown after exposure to H2O2 and acrylamide. The lowest dose...

  4. Yeast (Saccharomyces cereveresiae) Supplementation In High ...

    African Journals Online (AJOL)

    A four-week trial to assess the impact of yeast supplementation on the performance characteristics of broiler starters fed high levels of rice bran with or without yeast addition, was conducted using two hundred and forty day old broilers of the Bova nera strain. The chicks were divided into 15 groups of 16 chicks each.

  5. Virgin olive oil yeasts: A review.

    Science.gov (United States)

    Ciafardini, Gino; Zullo, Biagi Angelo

    2018-04-01

    This review summarizes current knowledge on virgin olive oil yeasts. Newly produced olive oil contains solid particles and micro drops of vegetation water in which yeasts reproduce to become the typical microbiota of olive oil. To date, about seventeen yeast species have been isolated from different types of olive oils and their by-products, of which six species have been identified as new species. Certain yeast species contribute greatly to improving the sensorial characteristics of the newly produced olive oil, whereas other species are considered harmful as they can damage the oil quality through the production of unpleasant flavors and triacylglycerol hydrolysis. Studies carried out in certain yeast strains have demonstrated the presence of defects in olive oil treated with Candida adriatica, Nakazawaea wickerhamii and Candida diddensiae specific strains, while other olive oil samples treated with other Candida diddensiae strains were defect-free after four months of storage and categorized as extra virgin. A new acetic acid producing yeast species, namely, Brettanomyces acidodurans sp. nov., which was recently isolated from olive oil, could be implicated in the wine-vinegary defect of the product. Other aspects related to the activity of the lipase-producing yeasts and the survival of the yeast species in the flavored olive oils are also discussed. Copyright © 2017 Elsevier Ltd. All rights reserved.

  6. Yeast evolution and ecology meet genomics

    OpenAIRE

    Dunham, Maitreya J.; Louis, Edward J.

    2010-01-01

    The EMBO Conference on Experimental Approaches to Evolution and Ecology in Yeast covered a broad range of interests. The applications of genomic methods to ecological and evolutionary questions emphasize that the yeasts are poised to make significant contributions to these fields.

  7. Exobiopolymer from polyhydroxyalkanoate-producing transgenic yeast

    African Journals Online (AJOL)

    Recently, the wild type yeast Kloeckera sp. strain KY1 was equipped in their cytoplasm with the phaABC operon containing genes phbA, phbB and phbC of the PHA biosynthetic pathway of Ralstonia eutropha. Unpredicted, resulted transgenic yeast strain KY1/PHA was able to synthesize another exopolymer beside the ...

  8. Biosynthesis of polyhydroxyalkanotes in wildtype yeasts | Desuoky ...

    African Journals Online (AJOL)

    Biosynthesis of the biodegradable polymers polyhydroxyalkanotes (PHAs) are studied extensively in wild type and genetically modified prokaryotic cells, however the content and structure of PHA in wild type yeasts are not well documented. The purpose of this study was to screen forty yeast isolates collected from different ...

  9. Yeasts in sustainable bioethanol production: A review

    Directory of Open Access Journals (Sweden)

    Siti Hajar Mohd Azhar

    2017-07-01

    Full Text Available Bioethanol has been identified as the mostly used biofuel worldwide since it significantly contributes to the reduction of crude oil consumption and environmental pollution. It can be produced from various types of feedstocks such as sucrose, starch, lignocellulosic and algal biomass through fermentation process by microorganisms. Compared to other types of microoganisms, yeasts especially Saccharomyces cerevisiae is the common microbes employed in ethanol production due to its high ethanol productivity, high ethanol tolerance and ability of fermenting wide range of sugars. However, there are some challenges in yeast fermentation which inhibit ethanol production such as high temperature, high ethanol concentration and the ability to ferment pentose sugars. Various types of yeast strains have been used in fermentation for ethanol production including hybrid, recombinant and wild-type yeasts. Yeasts can directly ferment simple sugars into ethanol while other type of feedstocks must be converted to fermentable sugars before it can be fermented to ethanol. The common processes involves in ethanol production are pretreatment, hydrolysis and fermentation. Production of bioethanol during fermentation depends on several factors such as temperature, sugar concentration, pH, fermentation time, agitation rate, and inoculum size. The efficiency and productivity of ethanol can be enhanced by immobilizing the yeast cells. This review highlights the different types of yeast strains, fermentation process, factors affecting bioethanol production and immobilization of yeasts for better bioethanol production.

  10. Sporangiospore - Yeast Transformation of Mucor circinelloides

    African Journals Online (AJOL)

    Charles

    2012-02-16

    Feb 16, 2012 ... Measurement of intracellular ion concentration during sporangiospores-yeast transformation of Mucor circinelloides .... Intercellular ion variation (K+, 0.90 g/l; Na+, 0.05 to 0.20 g/l) during sporangiospore-to-yeast transformation of M. circinelloides ...... progressive replication of DNA and, hence nucleation.

  11. Measurement of yeast invertase during alcoholic fermentation

    Energy Technology Data Exchange (ETDEWEB)

    Naudin, O.; Boudarel, M.J.; Ramirez, A.

    1986-01-01

    In continuous alcoholic fermentation of molasses by Saccharomyces cerevisiae, it is important but difficult to know the variation of yeast physiological state with time, so as to maintain maximum yeast productivity. We decided to quantify invertase activity, for which there are few if any appropriate methods (Vitolo and Borzani, Analytical Biochemistry 130, 469-470, 1983). 1 reference.

  12. Biodiesel generation from oleaginous yeast Rhodotorula glutinis ...

    African Journals Online (AJOL)

    This study explored a strategy to convert agricultural and forestry residues into microbial lipid, which could be further transformed into biodiesel. Among the 250 yeast strains screened for xylose assimilating capacity, eight oleaginous yeasts were selected by Sudan Black B test. The lipid content of these 8 strains was ...

  13. Growth requirements of san francisco sour dough yeasts and bakers' yeast.

    Science.gov (United States)

    Henry, N

    1976-03-01

    The growth requirements of several yeasts isolated from San Francisco sour dough mother sponges were compared with those of bakers' yeast. The sour dough yeasts studied were one strain of Saccharomyces uvarum, one strain of S. inusitatus, and four strains of S. exiguus. S. inusitatus was the only yeast found to have an amino acid requirement, namely, methionine. All of the yeasts had an absolute requirement for pantothenic acid and a partial requirement for biotin. Inositol was stimulatory to all except bakers' yeast. All strains of S. exiguus required niacin and thiamine. Interestingly, S. inusitatus, the only yeast that required methionine, also needed folic acid. For optimal growth of S. exiguus in a molasses medium, supplementation with thiamine was required.

  14. YEAST β-MANNANASE ACTIVITY

    Directory of Open Access Journals (Sweden)

    N. V. Borzova

    2017-02-01

    Full Text Available The aim of the research was to determine the mannan-degrading activity of yeasts cultures isolated from various sources and select strains with high β-mannanase activity. As a result of screening of 245 yeast strains, which are the representatives of 7 genera and 14 species, the active producers of extracellular β-mannanase were identified. To increase β-mannanase activity, the cultures were grown under submerged conditions using guar gum galactomannan as a carbon source and an inducer. β-Mannanase activity was determined by dinitrosalicylic method. The most active biosynthetic species were Cryptococcus albidus, C. gastricus, C. magnus, C. terreus, C. laurentii, Saccharomyces cerevisiae, Williopsis californica, Metschnikowia pulcherrima, Pichia anomala and P. guilliermondii. The activity in culture supernatant was ranged from 0.2 to 75 U/ml. α-Galactosidase activity was found in two strains (Debaryomyces polymorphus UCM Y-152 and Debaryomyces hansenii var. fabryi UCM Y-2400. None of the tested cultures demonstrated both β-mannanase and α-galactosidase activity, that is, they are unable to attack both the main and side chains of galactomannan.

  15. Mycotoxins - prevention and decontamination by yeasts.

    Science.gov (United States)

    Pfliegler, Walter P; Pusztahelyi, Tünde; Pócsi, István

    2015-07-01

    The application of yeasts has great potential in reducing the economic damage caused by toxigenic fungi in the agriculture. Some yeasts may act as biocontrol agents inhibiting the growth of filamentous fungi. These species may also gain importance in the preservation of agricultural products and in the reduction of their mycotoxin contamination, yet the extent of mycotoxin production in the presence of biocontrol agents is relatively less understood. The application of yeasts in various technological processes may have a direct inhibitory effect on the toxin production of certain molds, which is independent of their growth suppressing effect. Furthermore, several yeast species are capable of accumulating mycotoxins from agricultural products, thereby effectively decontaminating them. Probiotic yeasts or products containing yeast cell wall are also applied to counteract mycotoxicosis in livestock. Several yeast strains are also able to degrade toxins to less-toxic or even non-toxic substances. This intensively researched field would greatly benefit from a deeper knowledge on the genetic and molecular basis of toxin degradation. Moreover, yeasts and their biotechnologically important enzymes may exhibit sensitivity to certain mycotoxins, thereby mounting a considerable problem for the biotechnological industry. It is noted that yeasts are generally regarded as safe; however, there are reports of toxin degrading species that may cause human fungal infections. The aspects of yeast-mycotoxin relations with a brief consideration of strain improvement strategies and genetic modification for improved detoxifying properties and/or mycotoxin resistance are reviewed here. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  16. On the reduced lifetime of nitrous oxide due to climate change induced acceleration of the Brewer-Dobson circulation as simulated by the MPI Earth System Model

    Science.gov (United States)

    Kracher, D.; Manzini, E.; Reick, C. H.; Schultz, M. G.; Stein, O.

    2014-12-01

    Greenhouse gas induced climate change will modify the physical conditions of the atmosphere. One of the projected changes is an acceleration of the Brewer-Dobson circulation in the stratosphere, as it has been shown in many model studies. This change in the stratospheric circulation consequently bears an effect on the transport and distribution of atmospheric components such as N2O. Since N2O is involved in ozone destruction, a modified distribution of N2O can be of importance for ozone chemistry. N2O is inert in the troposphere and decays only in the stratosphere. Thus, changes in the exchange between troposphere and stratosphere can also affect the stratospheric sink of N2O, and consequently its atmospheric lifetime. N2O is a potent greenhouse gas with a global warming potential of currently approximately 300 CO2-equivalents in a 100-year perspective. A faster decay in atmospheric N2O mixing ratios, i.e. a decreased atmospheric lifetime of N2O, will also reduce its global warming potential. In order to assess the impact of climate change on atmospheric circulation and implied effects on the distribution and lifetime of atmospheric N2O, we apply the Max Planck Institute Earth System Model, MPI-ESM. MPI-ESM consists of the atmospheric general circulation model ECHAM, the land surface model JSBACH, and MPIOM/HAMOCC representing ocean circulation and ocean biogeochemistry. Prognostic atmospheric N2O concentrations in MPI-ESM are determined by land N2O emissions, ocean-atmosphere N2O exchange and atmospheric tracer transport. As stratospheric chemistry is not explicitly represented in MPI-ESM, stratospheric decay rates of N2O are prescribed from a MACC MOZART simulation. Increasing surface temperatures and CO2 concentrations in the stratosphere impact atmospheric circulation differently. Thus, we conduct a series of transient runs with the atmospheric model of MPI-ESM to isolate different factors governing a shift in atmospheric circulation. From those transient

  17. Frequency of wet brewers grains supplementation during late gestation of beef cows and its effects on offspring postnatal growth and immunity.

    Science.gov (United States)

    Moriel, P; Artioli, L F A; Piccolo, M B; Marques, R S; Poore, M H; Cooke, R F

    2016-06-01

    Our objectives were to evaluate postnatal growth and measurements of innate and humoral immunity of beef calves born to dams fed wet brewers grains (WBG) daily or 3 times weekly during late gestation. On d 0 (approximately 60 d before calving), 28 multiparous, spring-calving Angus cows (BW = 578 ± 19 kg; age = 4.7 ± 0.65 yr; BCS = 7.0 ± 0.18) were stratified by sire, age, BW, and BCS and then randomly allocated into 1 of 14 drylot pens (2 cows/pen; 18 by 3 m; 27 m/cow). Cows were offered ground tall fescue hay ad libitum and received similar weekly WBG supplementation (DMI = 0.5% of BW multiplied by 7 d). Treatments were randomly assigned to pens (7 pens/treatment) and consisted of cows receiving WBG supplementation daily (S7; weekly DMI of WBG divided by 7 d) or 3 times weekly (S3; weekly DMI of WBG divided by 3 d; Mondays, Wednesdays, and Fridays) from d 0 until calving. Cow-calf pairs were managed as a single group on tall fescue pastures from calving to weaning (d 226). Calves were immediately submitted to a preconditioning period from d 226 to 266 and vaccinated against infectious bovine rhinotracheitis, bovine viral diarrhea virus, , and on d 231 and 245. Decreasing the frequency of WBG supplementation did not impact ( ≥ 0.21) precalving intake of total DM, CP, and TDN; BW and BCS change; overall plasma cortisol concentrations; and postcalving growth and pregnancy rate of cows. Overall plasma concentrations of glucose and insulin did not differ ( ≥ 0.28) between S3 and S7 cows, whereas S3 cows had greater ( = 0.002) plasma glucose concentrations and tended ( = 0.06) to have greater plasma insulin concentrations on days they were not fed WBG vs. days of WBG supplementation. Calf plasma concentrations of haptoglobin and cortisol at birth but not serum IgG ( = 0.63) tended ( = 0.10) to be greater for S3 vs. S7 calves. However, additional calf growth and immunity variables obtained during pre- and postweaning phases did not differ between S3 and S7 calves

  18. Rheologically interesting polysaccharides from yeasts

    Science.gov (United States)

    Petersen, G. R.; Nelson, G. A.; Cathey, C. A.; Fuller, G. G.

    1989-01-01

    We have examined the relationships between primary, secondary, and tertiary structures of polysaccharides exhibiting the rheological property of friction (drag) reduction in turbulent flows. We found an example of an exopolysaccharide from the yeast Cryptococcus laurentii that possessed high molecular weight but exhibited lower than expected drag reducing activity. Earlier correlations by Hoyt showing that beta 1 --> 3, beta 2 --> 4, and alpha 1 --> 3 linkages in polysaccharides favored drag reduction were expanded to include correlations to secondary structure. The effect of sidechains in a series of gellan gums was shown to be related to sidechain length and position. Disruption of secondary structure in drag reducing polysaccharides reduced drag reducing activity for some but not all exopolysaccharides. The polymer from C. laurentii was shown to be more stable than xanthan gum and other exopolysaccharides under the most vigorous of denaturing conditions. We also showed a direct relationship between extensional viscosity measurements and the drag reducing coefficient for four exopolysaccharides.

  19. Yeast-based biosensors: design and applications.

    Science.gov (United States)

    Adeniran, Adebola; Sherer, Michael; Tyo, Keith E J

    2015-02-01

    Yeast-based biosensing (YBB) is an exciting research area, as many studies have demonstrated the use of yeasts to accurately detect specific molecules. Biosensors incorporating various yeasts have been reported to detect an incredibly large range of molecules including but not limited to odorants, metals, intracellular metabolites, carcinogens, lactate, alcohols, and sugars. We review the detection strategies available for different types of analytes, as well as the wide range of output methods that have been incorporated with yeast biosensors. We group biosensors into two categories: those that are dependent upon transcription of a gene to report the detection of a desired molecule and those that are independent of this reporting mechanism. Transcription-dependent biosensors frequently depend on heterologous expression of sensing elements from non-yeast organisms, a strategy that has greatly expanded the range of molecules available for detection by YBBs. Transcription-independent biosensors circumvent the problem of sensing difficult-to-detect analytes by instead relying on yeast metabolism to generate easily detected molecules when the analyte is present. The use of yeast as the sensing element in biosensors has proven to be successful and continues to hold great promise for a variety of applications. © FEMS 2015. All rights reserved. For permissions, please e-mail: journals.permission@oup.com.

  20. Accelerating Yeast Prion Biology using Droplet Microfluidics

    Science.gov (United States)

    Ung, Lloyd; Rotem, Assaf; Jarosz, Daniel; Datta, Manoshi; Lindquist, Susan; Weitz, David

    2012-02-01

    Prions are infectious proteins in a misfolded form, that can induce normal proteins to take the misfolded state. Yeast prions are relevant, as a model of human prion diseases, and interesting from an evolutionary standpoint. Prions may also be a form of epigenetic inheritance, which allow yeast to adapt to stressful conditions at rates exceeding those of random mutations and propagate that adaptation to their offspring. Encapsulation of yeast in droplet microfluidic devices enables high-throughput measurements with single cell resolution, which would not be feasible using bulk methods. Millions of populations of yeast can be screened to obtain reliable measurements of prion induction and loss rates. The population dynamics of clonal yeast, when a fraction of the cells are prion expressing, can be elucidated. Furthermore, the mechanism by which certain strains of bacteria induce yeast to express prions in the wild can be deduced. Integrating the disparate fields of prion biology and droplet microfluidics reveals a more complete picture of how prions may be more than just diseases and play a functional role in yeast.

  1. 21 CFR 172.325 - Bakers yeast protein.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Bakers yeast protein. 172.325 Section 172.325 Food... Special Dietary and Nutritional Additives § 172.325 Bakers yeast protein. Bakers yeast protein may be safely used in food in accordance with the following conditions: (a) Bakers yeast protein is the...

  2. Yeast cell factories on the horizon

    DEFF Research Database (Denmark)

    Nielsen, Jens

    2015-01-01

    been engineered to make chemicals at industrial scale (e.g., succinic acid, lactic acid, resveratrol) and advanced biofuels (e.g., isobutanol) (1). On page 1095 of this issue, Galanie et al. (2) demonstrate that yeast can now be engineered to produce opioids (2), a major class of compounds used...... for treating severe pain. Their study represents a tour de force in the metabolic engineering of yeast, as it involved the expression of genes for more than 20 enzymatic activities from plants, mammals, bacteria, and yeast itself. It clearly represents a breakthrough advance for making complex natural products...

  3. Chemical gradients and chemotropism in yeast.

    Science.gov (United States)

    Arkowitz, Robert A

    2009-08-01

    Chemical gradients of peptide mating pheromones are necessary for directional growth, which is critical for yeast mating. These gradients are generated by cell-type specific secretion or export and specific degradation in receiving cells. Spatial information is sensed by dedicated seven-transmembrane G-protein coupled receptors and yeast cells are able to detect extremely small differences in ligand concentration across their approximately 5-microm cell surface. Here, I will discuss our current knowledge of how cells detect and respond to such shallow chemical gradients and in particular what is known about the proteins that are involved in directional growth and the establishment of the polarity axis during yeast mating.

  4. YeastWeb: a workset-centric web resource for gene family analysis in yeast

    Directory of Open Access Journals (Sweden)

    Bao Haihua

    2010-07-01

    Full Text Available Abstract Background Currently, a number of yeast genomes with different physiological features have been sequenced and annotated, which provides invaluable information to investigate yeast genetics, evolutionary mechanism, structure and function of gene families. Description YeastWeb is a novel database created to provide access to gene families derived from the available yeast genomes by assigning the genes into putative families. It has many useful features that complement existing databases, such as SGD, CYGD and Génolevures: 1 Detailed computational annotation was conducted with each entry with InterProScan, EMBOSS and functional/pathway databases, such as GO, COG and KEGG; 2 A well established user-friendly environment was created to allow users to retrieve the annotated genes and gene families using functional classification browser, keyword search or similarity-based search; 3 Workset offers users many powerful functions to manage the retrieved data efficiently, associate the individual items easily and save the intermediate results conveniently; 4 A series of comparative genomics and molecular evolution analysis tools are neatly implemented to allow users to view multiple sequence alignments and phylogenetic tree of gene families. At present, YeastWeb holds the gene families clustered from various MCL inflation values from a total of 13 available yeast genomes. Conclusions Given the great interest in yeast research, YeastWeb has the potential to become a useful resource for the scientific community of yeast biologists and related researchers investigating the evolutionary relationship of yeast gene families. YeastWeb is available at http://centre.bioinformatics.zj.cn/Yeast/.

  5. NetPhosYeast: prediction of protein phosphorylation sites in yeast

    DEFF Research Database (Denmark)

    Ingrell, C.R.; Miller, Martin Lee; Jensen, O.N.

    2007-01-01

    We here present a neural network-based method for the prediction of protein phosphorylation sites in yeast-an important model organism for basic research. Existing protein phosphorylation site predictors are primarily based on mammalian data and show reduced sensitivity on yeast phosphorylation...... sites compared to those in humans, suggesting the need for an yeast-specific phosphorylation site predictor. NetPhosYeast achieves a correlation coefficient close to 0.75 with a sensitivity of 0.84 and specificity of 0.90 and outperforms existing predictors in the identification of phosphorylation sites...

  6. Systems biology of energy homeostasis in yeast.

    Science.gov (United States)

    Zhang, Jie; Vemuri, Goutham; Nielsen, Jens

    2010-06-01

    The yeast Saccharomyces cerevisiae attains energy homeostasis through complex regulatory events that are predominantly controlled by the Snf1 kinase. This master regulator senses the stress and energy starvation and activates the metabolic processes to produce ATP and inhibits biosynthesis. In doing so, Snf1 controls the switch between catabolism and anabolism accordingly, and regulates the cellular growth and development in coordination with other signaling pathways. Since its mammalian ortholog AMPK, a drug target for obesity and type II diabetes, also exerts analogous control of metabolism, there has been extensive interest recently to understand the chemical and biological aspects of Snf1 activation and regulation in yeast to expedite human disease studies as well as fundamental understanding of yeast. This review will focus on how Snf1 regulates lipid metabolism based on the cellular energy status in yeast and drawing parallels with the mammalian system. Copyright 2010 Elsevier Ltd. All rights reserved.

  7. [Red yeast rice: An unsafe food supplement?

    Science.gov (United States)

    Steffen, Christian

    2017-03-01

    Red yeast rice is the fermentation product of the mould Monascus ruber and is traditionally used in East Asia to dye and conserve food. Its main pharmacologically active compound, monakolin K, was isolated from red yeast rice and is used as an inhibitor of cholesterol synthesis under the INN lovastatin. Lovastatin and several other statins are marketed as drugs whereas red yeast rice is offered as a food supplement. As statins can cause severe side effects, such as muscle damage and kidney failure, the dosing and information about interactions with drugs and food is essential for the use of these products. Furthermore, red yeast rice can contain the mycotoxin citrinin and several other substances that are not yet toxicologically evaluated.

  8. Sporulation in the budding yeast Saccharomyces cerevisiae

    National Research Council Canada - National Science Library

    Neiman, Aaron M

    2011-01-01

    In response to nitrogen starvation in the presence of a poor carbon source, diploid cells of the yeast Saccharomyces cerevisiae undergo meiosis and package the haploid nuclei produced in meiosis into spores...

  9. Genomic Evolution of the Ascomycete Yeasts

    Energy Technology Data Exchange (ETDEWEB)

    Riley, Robert; Haridas, Sajeet; Salamov, Asaf; Boundy-Mills, Kyria; Goker, Markus; Hittinger, Chris; Klenk, Hans-Peter; Lopes, Mariana; Meir-Kolthoff, Jan P.; Rokas, Antonis; Rosa, Carlos; Scheuner, Carmen; Soares, Marco; Stielow, Benjamin; Wisecaver, Jennifer H.; Wolfe, Ken; Blackwell, Meredith; Kurtzman, Cletus; Grigoriev, Igor; Jeffries, Thomas

    2015-03-16

    Yeasts are important for industrial and biotechnological processes and show remarkable metabolic and phylogenetic diversity despite morphological similarities. We have sequenced the genomes of 16 ascomycete yeasts of taxonomic and industrial importance including members of Saccharomycotina and Taphrinomycotina. Phylogenetic analysis of these and previously published yeast genomes helped resolve the placement of species including Saitoella complicata, Babjeviella inositovora, Hyphopichia burtonii, and Metschnikowia bicuspidata. Moreover, we find that alternative nuclear codon usage, where CUG encodes serine instead of leucine, are monophyletic within the Saccharomycotina. Most of the yeasts have compact genomes with a large fraction of single exon genes, and a tendency towards more introns in early-diverging species. Analysis of enzyme phylogeny gives insights into the evolution of metabolic capabilities such as methanol utilization and assimilation of alternative carbon sources.

  10. Structure and function of yeast alcohol dehydrogenase

    Directory of Open Access Journals (Sweden)

    VLADIMIR LESKOVAC

    2000-04-01

    Full Text Available 1. Introduction 2. Isoenzymes of YADH 3. Substrate specificity 4. Kinetic mechanism 5. Primary structure 6. The active site 7. Mutations in the yeast enzyme 8. Chemical mechanism 9. Binding of coenzymes 10. Hydride transfer

  11. Propagation of Mammalian Prions in Yeast

    National Research Council Canada - National Science Library

    Harris, David A

    2006-01-01

    ...: the budding yeast Saccharomyces cerevisiae. This unicellular organism offers a number of potential advantages for the study of prion biology, including rapid generation time, ease of culturing, and facile genetics...

  12. ADSORPTION ONTO BREWERS' SPENT GRAIN

    African Journals Online (AJOL)

    user

    metal plating, mining activities, smelting, battery manufacture, tanneries, petroleum refining, paint manufacture .... Intafact Breweries Limited, Onitsha, Anambra State,. Nigeria. The adsorbent was air dried, pulverized and ..... the uptake of lead and zinc by lignin obtained from black Liquor- A paper industry waste material”,.

  13. Live Cell Imaging in Fission Yeast.

    Science.gov (United States)

    Mulvihill, Daniel P

    2017-10-03

    Live cell imaging complements the array of biochemical and molecular genetic approaches to provide a comprehensive insight into functional dependencies and molecular interactions in fission yeast. Fluorescent proteins and vital dyes reveal dynamic changes in the spatial distribution of organelles and the proteome and how each alters in response to changes in environmental and genetic composition. This introduction discusses key issues and basic image analysis for live cell imaging of fission yeast. © 2017 Cold Spring Harbor Laboratory Press.

  14. Multidrug resistant yeasts in synanthropic wild birds

    Directory of Open Access Journals (Sweden)

    Somanath Sushela

    2010-03-01

    Full Text Available Abstract Background The aim of this study was to investigate the presence of multidrug resistant yeasts in the faeces of synanthropic wild birds from the Bangsar suburb of Kuala Lumpur. Methods Species characterisations of yeast isolates and determinations of antimycotic susceptibility profiles were undertaken using the commercial characterization kit, Integral System Yeasts Plus (Liofilchem, Italy. Results Fourteen species of yeasts were detected in the bird faecal samples.Candida albicans was present in 28.89% of bird faecal samples, Candida krusei (13.33%, Candida tropicalis (4.44%, Candida glabrata (4.44%, Candida parapsilosis (2.22%, Candida lambica (2.22%, Candida stellatoidea (2.22%, Candida rugosa (2.22% and Candida lusitaniae (2.22%. Amongst the non-candidal yeast isolates, Cryptococcus laurentii was present in 6.67% of bird faecal samples, Cryptococcus uniguttulatus (4.44%, Saccharomyces cerevisiae (4.44%, Trichosporon pullulans (2.22%, Trichosporon pullulans/Cryptococcus albidus (8.89% and Rhodotorula rubra/Rhodotorula glutinis (4.44%. Of the isolated yeasts, 18.1% (or 26/144 were found to be resistant to all 11 antimycotic agents they were tested against i.e. Nystatin, Amphotericin B, Flucytosine, Econazole, Ketoconazole, Clotrimazole, Miconazole, Itraconazole, Voriconazole, Fluconazole 16 and Fluconazole 64. 45.8% (or 66/144 of the bird faecal yeast isolates were resistant to four or more of the 11 antimycotic agents they were tested against. Conclusions This finding is of public health significance as these synanthropic wild birds may be reservoirs for transmission of drug resistant yeast infections to humans.

  15. Yeasts are essential for cocoa bean fermentation.

    Science.gov (United States)

    Ho, Van Thi Thuy; Zhao, Jian; Fleet, Graham

    2014-03-17

    Cocoa beans (Theobroma cacao) are the major raw material for chocolate production and fermentation of the beans is essential for the development of chocolate flavor precursors. In this study, a novel approach was used to determine the role of yeasts in cocoa fermentation and their contribution to chocolate quality. Cocoa bean fermentations were conducted with the addition of 200ppm Natamycin to inhibit the growth of yeasts, and the resultant microbial ecology and metabolism, bean chemistry and chocolate quality were compared with those of normal (control) fermentations. The yeasts Hanseniaspora guilliermondii, Pichia kudriavzevii and Kluyveromyces marxianus, the lactic acid bacteria Lactobacillus plantarum and Lactobacillus fermentum and the acetic acid bacteria Acetobacter pasteurianus and Gluconobacter frateurii were the major species found in the control fermentation. In fermentations with the presence of Natamycin, the same bacterial species grew but yeast growth was inhibited. Physical and chemical analyses showed that beans fermented without yeasts had increased shell content, lower production of ethanol, higher alcohols and esters throughout fermentation and lesser presence of pyrazines in the roasted product. Quality tests revealed that beans fermented without yeasts were purplish-violet in color and not fully brown, and chocolate prepared from these beans tasted more acid and lacked characteristic chocolate flavor. Beans fermented with yeast growth were fully brown in color and gave chocolate with typical characters which were clearly preferred by sensory panels. Our findings demonstrate that yeast growth and activity were essential for cocoa bean fermentation and the development of chocolate characteristics. Crown Copyright © 2014. Published by Elsevier B.V. All rights reserved.

  16. Yeast evolution and ecology meet genomics.

    Science.gov (United States)

    Dunham, Maitreya J; Louis, Edward J

    2011-01-01

    The first EMBO Conference on Experimental Approaches to Evolution and Ecology in Yeast was held in Heidelberg, Germany, at the end of September 2010. What might sound like a rather narrow topic actually covered a broad range of interests, approaches, and systems and generated a great deal of excitement among participants. The applications of genomic methods to ecological and evolutionary questions emphasize that the yeasts are poised to make significant contributions to these fields.

  17. Yeast communities in a natural tequila fermentation.

    Science.gov (United States)

    Lachance, M A

    1995-08-01

    Fresh and cooked agave, Drosophila spp., processing equipment, agave molasses, agave extract, and fermenting must at a traditional tequila distillery (Herradura, Amatitan, Jalisco, México) were studied to gain insight on the origin of yeasts involved in a natural tequila fermentations. Five yeast communities were identified. (1) Fresh agave contained a diverse mycobiota dominated by Clavispora lusitaniae and an endemic species, Metschnikowia agaveae. (2) Drosophila spp. from around or inside the distillery yielded typical fruit yeasts, in particular Hanseniaspora spp., Pichia kluyveri, and Candida krusei. (3) Schizosaccharomyces pombe prevailed in molasses. (4) Cooked agave and extract had a considerable diversity of species, but included Saccharomyces cerevisiae. (5) Fermenting juice underwent a gradual reduction in yeast heterogeneity. Torulaspora delbrueckii, Kluyveromyces marxianus, and Hanseniaspora spp. progressively ceded the way to S. cerevisiae, Zygosaccharomyces bailii, Candida milleri, and Brettanomyces spp. With the exception of Pichia membranaefaciens, which was shared by all communities, little overlap existed. That separation was even more manifest when species were divided into distinguishable biotypes based on morphology or physiology. It is concluded that crushing equipment and must holding tanks are the main source of significant inoculum for the fermentation process. Drosophila species appear to serve as internal vectors. Proximity to fruit trees probably contributes to maintaining a substantial Drosophila community, but the yeasts found in the distillery exhibit very little similarity to those found in adjacent vegetation. Interactions involving killer toxins had no apparent direct effects on the yeast community structure.

  18. Revaluation of Waste Yeast from Beer Production

    Directory of Open Access Journals (Sweden)

    Nicoleta Suruceanu

    2013-11-01

    Full Text Available Brewing yeast is an important waste product from beer production. The valorification of slurry yeast mainly consists of separation of vitamins and important nitrogen compounds. The hops compounds, one of the most important raw materials in beer technology are removed beforehand valorification. The prenylflavonoids compounds from hops are important bioactive compounds that can be revaluation with proper technology. Revaluation of prenylflavonoids from waste yeast into dietary supplement, identification and quantification of xanthohumol by HPLC method. Waste yeast from brewery pilot plant of USAMV Cluj Napoca it was dried by atomization and the powder was analyzed on xanthohumol content by HPLC method. For quantification a calibration curve it was used. The process of drying by atomisation lead to a powder product. It was used malt dextrin powder for stabilisation. The final product it was encapsulated. The xanthohumol content of powdered yeast it was 1.94 µg/ml. In conclusion the slurry yeast from beer production it is an important source of prenylflavonoids compounds.

  19. Flor yeast: new perspectives beyond wine ageing

    Directory of Open Access Journals (Sweden)

    Jean-luc eLegras

    2016-04-01

    Full Text Available The most important dogma in white-wine production is the preservation of the wine aroma and the limitation of the oxidative action of oxygen. In contrast, the ageing of Sherry and Sherry-like wines is an aerobic process that depends on the oxidative activity of flor strains of Saccharomyces cerevisiae. Under depletion of nitrogen and fermentable carbon sources, these yeast produce aggregates of floating cells and form an air-liquid biofilm on the wine surface, which is also known as the velum or flor. This behaviour is due to genetic and metabolic peculiarities that differentiate flor yeast from other wine yeast. This review will focus first on the most updated data obtained through the analysis of flor yeast with -omic tools. Comparative genomics, proteomics and metabolomics of flor and wine yeast strains are shedding new light on several features of these special yeast, and in particular, they have revealed the extent of proteome remodelling imposed by the biofilm life-style. Finally, new insights in terms of promotion and inhibition of biofilm formation through small molecules, amino acids and di/tri-peptides, and novel possibilities for the exploitation of biofilm immobilisation within a fungal hyphae framework, will be discussed.

  20. Studies on yeast nucleoside triphosphate-nucleoside diphosphate transphosphorylase (nucleoside diphosphokinase). IV. Steady-state kinetic properties with thymidine nucleotides (including 3'-azido-3'-deoxythymidine analogues).

    Science.gov (United States)

    Kuby, S A; Fleming, G; Alber, T; Richardson, D; Takenaka, H; Hamada, M

    1991-01-01

    A study of the steady-state kinetics of the crystalline brewer's yeast (Saccharomyces carlsbergensis) nucleoside diphosphokinase, with the magnesium complexes of the adenine and thymidine nucleotides as reactants, has led to a postulated kinetic mechanism which proceeds through a substituted enzyme. This agrees with the earlier conclusions of Garces and Cleland [Biochemistry 1969; 8:633-640] who characterized a reaction between the magnesium complexes of the adenine and uridine nucleotides. An advantage of using thymidine nucleotides as reactants is that they permit accurate, rapid and continuous assays of the enzymatic activity in coupled-enzymatic tests. Through measurements of the initial velocities and product inhibition studies, the Michaelis constants, maximum velocities, and inhibition constants could be evaluated for the individual substrates. Competitive substrate inhibition was encountered at relatively high substrate concentrations, which also permitted an evaluation of their ability to act as 'dead-end' inhibitors. The Michaelis constants for the 3'-azido-3'-deoxythymidine (AzT) analogues were also evaluated and, although these values were only somewhat higher than those of their natural substrates, the Km's for the adenine nucleotides as paired substrates were lower and the Vmax's were drastically reduced. The pharmacological implications of these observations are touched upon and extrapolated to the cases where therapeutic doses of AzT may be employed.

  1. Dobson, Brewer, ERA-40 and ERA-Interim original and merged total ozone data sets – evaluation of differences: a case study, Hradec Králové (Czech, 1961–2010

    Directory of Open Access Journals (Sweden)

    K. Vaníček

    2012-09-01

    Full Text Available Homogenized data series of total ozone measurements taken by the regularly and well calibrated Dobson and Brewer spectrophotometers at Hradec Králové (Czech and the data from the re-analyses ERA-40 and ERA-Interim were merged and compared to investigate differences between the particular data sets originated in Central Europe, the Northern Hemisphere (NH mid-latitudes. The Dobson-to-Brewer transfer function and the algorithm for approximation of the data from the re-analyses were developed, tested and applied for creation of instrumentally consistent and completed total ozone data series of the 50-yr period 1961–2010 of observations. This correction has reduced the well-known seasonal differences between Dobson and Brewer data below the 1% calibration limit of the spectrophotometers. Incorporation of the ERA-40 and ERA-Interim total ozone data on days with missing measurements significantly improved completeness and reliability of the data series mainly in the first two decades of the period concerned. Consistent behaviour of the original and corrected/merged data sets was found in the pre-ozone-hole period (1961–1985. In the post-Pinatubo (1994–2010 era the data series show seasonal differences that can introduce uncertainty in estimation of ozone recovery mainly in the winter-spring season when the effect of the Montreal Protocol and its Amendments is expected. All the data sets confirm substantial depletion of ozone also in the summer months that gives rise to the question about its origin. The merged and completed data series of total ozone will be further analyzed to quantify chemical ozone losses and contribution of natural atmospheric processes to the ozone depletion over the region. This case study points out the importance of selection and evaluation of the quality and consistency of the input data sets used in estimation of long-term ozone changes including recovery of the ozone layer over the selected areas. Data are available

  2. Yeast Interacting Proteins Database: YGR113W, YGL079W [Yeast Interacting Proteins Database

    Lifescience Database Archive (English)

    Full Text Available sion protein localizes to the endosome; identified as a transcriptional activator in a high-throughput yeast... a transcriptional activator in a high-throughput yeast one-hybrid assay Rows with this prey as prey Rows wi

  3. Yeast Interacting Proteins Database: YFR015C, YFR015C [Yeast Interacting Proteins Database

    Lifescience Database Archive (English)

    Full Text Available yeast homolog; expression induced by glucose limitation, nitrogen starvation, environmental stress, and entr...ression induced by glucose limitation, nitrogen starvation, environmental stress, and entry into stationary ...tion, nitrogen starvation, environmental stress, and entry into stationary phase Rows with this bait as bait..., the more highly expressed yeast homolog; expression induced by glucose limitation, nitrogen starvation, environmental

  4. Discussion of teleomorphic and anamorphic Ascomycetous yeasts and yeast-like taxa

    Science.gov (United States)

    The relationship of ascomycetous yeasts with other members of the ascomycete fungi (Ascomycota) has been controversial for over 100 years. Because yeasts are morphologically simple, it was proposed that they represent primitive forms of ascomycetes (e.g., Guilliermond 1912). Alternatively, the ide...

  5. Boolean model of yeast apoptosis as a tool to study yeast and human apoptotic regulations.

    Science.gov (United States)

    Kazemzadeh, Laleh; Cvijovic, Marija; Petranovic, Dina

    2012-01-01

    Programmed cell death (PCD) is an essential cellular mechanism that is evolutionary conserved, mediated through various pathways and acts by integrating different stimuli. Many diseases such as neurodegenerative diseases and cancers are found to be caused by, or associated with, regulations in the cell death pathways. Yeast Saccharomyces cerevisiae, is a unicellular eukaryotic organism that shares with human cells components and pathways of the PCD and is therefore used as a model organism. Boolean modeling is becoming promising approach to capture qualitative behavior and describe essential properties of such complex networks. Here we present large literature-based and to our knowledge first Boolean model that combines pathways leading to apoptosis (a type of PCD) in yeast. Analysis of the yeast model confirmed experimental findings of anti-apoptotic role of Bir1p and pro-apoptotic role of Stm1p and revealed activation of the stress protein kinase Hog proposing the maximal level of activation upon heat stress. In addition we extended the yeast model and created an in silico humanized yeast in which human pro- and anti-apoptotic regulators Bcl-2 family and Valosin-contain protein (VCP) are included in the model. We showed that accumulation of Bax in silico humanized yeast shows apoptotic markers and that VCP is essential target of Akt Signaling. The presented Boolean model provides comprehensive description of yeast apoptosis network behavior. Extended model of humanized yeast gives new insights of how complex human disease like neurodegeneration can initially be tested.

  6. Differences between flocculating yeast and regular industrial yeast in transcription and metabolite profiling during ethanol fermentation

    Directory of Open Access Journals (Sweden)

    Lili Li

    2017-03-01

    Full Text Available Objectives: To improve ethanolic fermentation performance of self-flocculating yeast, difference between a flocculating yeast strain and a regular industrial yeast strain was analyzed by transcriptional and metabolic approaches. Results: The number of down-regulated (industrial yeast YIC10 vs. flocculating yeast GIM2.71 and up-regulated genes were 4503 and 228, respectively. It is the economic regulation for YIC10 that non-essential genes were down-regulated, and cells put more “energy” into growth and ethanol production. Hexose transport and phosphorylation were not the limiting-steps in ethanol fermentation for GIM2.71 compared to YIC10, whereas the reaction of 1,3-disphosphoglycerate to 3-phosphoglycerate, the decarboxylation of pyruvate to acetaldehyde and its subsequent reduction to ethanol were the most limiting steps. GIM2.71 had stronger stress response than non-flocculating yeast and much more carbohydrate was distributed to other bypass, such as glycerol, acetate and trehalose synthesis. Conclusions: Differences between flocculating yeast and regular industrial yeast in transcription and metabolite profiling will provide clues for improving the fermentation performance of GIM2.71.

  7. 27 CFR 25.252 - Records.

    Science.gov (United States)

    2010-04-01

    ... TREASURY LIQUORS BEER Removal of Brewer's Yeast and Other Articles § 25.252 Records. (a) Production. The brewer shall keep records of the production of malt syrup, wort, and other articles which are removed...

  8. Influence of pesticides on yeasts colonizing leaves.

    Science.gov (United States)

    Vadkertiová, Renata; Sláviková, Elena

    2011-01-01

    The effect of nine different pesticides on the growth of yeasts isolated from the leaves of fruit and forest trees was investigated. Four insecticides (with the active ingredients: thiacloprid, deltamethrin, lambdacyhalothrin, and thiamethoxam) and five fungicides (with the effective substances: bitertanol, kresoxim-methyl, mancozeb, trifloxystrobin, and cupric oxychloride) were tested. The concentrations of chemicals were those recommended by the manufacturers for the spraying of trees. The yeast strains isolated from the leaves of fruit trees were not sensitive to any of the insecticides. The majority of yeast strains isolated from the leaves of forest trees were either not sensitive or only to a small extent. While Rhodotorula mucilaginosa and Pichia anomala were not affected by any insecticide, the strains of Cryptococcus laurentii and Rhodotorula glutinis showed the highest sensitivity. The effects of fungicides on the growth of isolated yeasts were more substantial. The fungicide Dithane DG (mancozeb) completely inhibited the growth of all yeasts. All strains isolated from fruit tree leaves were more resistant to the tested fungicides than those isolated from the leaves of forest trees. The most resistant strains from the leaves of fruit trees belonged to the species Metschnikowia pulcherrima, Pichia anomala, and Saccharomyces cerevisiae, whereas Cryptococcus albidus and C. laurentii, originating from the leaves of forest trees, showed the highest sensitivity to fungicides.

  9. Extension of yeast chronological lifespan by methylamine.

    Directory of Open Access Journals (Sweden)

    Sanjeev Kumar

    Full Text Available BACKGROUND: Chronological aging of yeast cells is commonly used as a model for aging of human post-mitotic cells. The yeast Saccharomyces cerevisiae grown on glucose in the presence of ammonium sulphate is mainly used in yeast aging research. We have analyzed chronological aging of the yeast Hansenula polymorpha grown at conditions that require primary peroxisome metabolism for growth. METHODOLOGY/PRINCIPAL FINDINGS: The chronological lifespan of H. polymorpha is strongly enhanced when cells are grown on methanol or ethanol, metabolized by peroxisome enzymes, relative to growth on glucose that does not require peroxisomes. The short lifespan of H. polymorpha on glucose is mainly due to medium acidification, whereas most likely ROS do not play an important role. Growth of cells on methanol/methylamine instead of methanol/ammonium sulphate resulted in further lifespan enhancement. This was unrelated to medium acidification. We show that oxidation of methylamine by peroxisomal amine oxidase at carbon starvation conditions is responsible for lifespan extension. The methylamine oxidation product formaldehyde is further oxidized resulting in NADH generation, which contributes to increased ATP generation and reduction of ROS levels in the stationary phase. CONCLUSION/SIGNIFICANCE: We conclude that primary peroxisome metabolism enhanced chronological lifespan of H. polymorpha. Moreover, the possibility to generate NADH at carbon starvation conditions by an organic nitrogen source supports further extension of the lifespan of the cell. Consequently, the interpretation of CLS analyses in yeast should include possible effects on the energy status of the cell.

  10. Cell polarization in budding and fission yeasts.

    Science.gov (United States)

    Martin, Sophie G; Arkowitz, Robert A

    2014-03-01

    Polarization is a fundamental cellular property, which is essential for the function of numerous cell types. Over the past three to four decades, research using the best-established yeast systems in cell biological research, Saccharomyces cerevisiae (or budding yeast) and Schizosaccharomyces pombe (or fission yeast), has brought to light fundamental principles governing the establishment and maintenance of a polarized, asymmetric state. These two organisms, though both ascomycetes, are evolutionarily very distant and exhibit distinct shapes and modes of growth. In this review, we compare and contrast the two systems. We first highlight common cell polarization pathways, detailing the contribution of Rho GTPases, the cytoskeleton, membrane trafficking, lipids, and protein scaffolds. We then contrast the major differences between the two organisms, describing their distinct strategies in growth site selection and growth zone dimensions and compartmentalization, which may be the basis for their distinct shapes. © 2013 Federation of European Microbiological Societies. Published by John Wiley & Sons Ltd. All rights reserved.

  11. Yeast interactions in inoculated wine fermentation

    Directory of Open Access Journals (Sweden)

    Maurizio eCiani

    2016-04-01

    Full Text Available The use of selected starter culture is widely diffused in winemaking. In pure fermentation, the ability of inoculated Saccharomyces cerevisiae to suppress the wild microflora is one of the most important feature determining the starter ability to dominate the process. Since the wine is the result of the interaction of several yeast species and strains, many studies are available on the effect of mixed cultures on the final wine quality. In mixed fermentation the interactions between the different yeasts composing the starter culture can led the stability of the final product and the analytical and aromatic profile. In the present review, we will discuss the recent developments regarding yeast interactions in pure and in mixed fermentation, focusing on the influence of interactions on growth and dominance in the process.

  12. [Molecular taxonomy techniques used for yeast identification].

    Science.gov (United States)

    Ghindea, Raluca; Csutak, Ortansa; Stoica, Ileana; Ionescu, Robertina; Soare, Simona; Pelinescu, Diana; Nohit, Ana-Maria; Creangă, Oana; Vassu, Tatiana

    2004-01-01

    Due to the major impact of yeasts in human life based on the existence of pathogen yeast species and of species with biotechnological abilities, in the last few years new molecular techniques are performed for an accurate identification of natural isolates. Our study is aimed to review some of these techniques such as electrokariotyping by PFGE (Pulsed Field Gel Electrophoresis), estimation of the molar percentage of guanine and cytosine, the applications of PCR reaction in yeast identification using RAPD (Random amplified polymorphic DNA), UP-PCR (Universally Primed Polymerase Chain Reaction), MLST (Multilocus sequence typing) techniques, mtDNA and rDNA homology studies. Such molecular techniques complete the phenotypical characterization based on classical taxonomical tests allowing thus the polyphasic identification of the microorganisms.

  13. Bioadsorption strategies with yeast molecular display technology.

    Science.gov (United States)

    Shibasaki, Seiji; Ueda, Mitsuyoshi

    2014-01-01

    Molecular display techniques using microbial cell surfaces have been widely developed in the past twenty years, and are useful tools as whole cell catalysts for various applications such as bioconversion, bioremediation, biosensing, and the screening system of protein libraries. Furthermore, different types of microbial cells among eukaryotic and prokaryotic strains have been investigated for their use in surface display technologies. Recently, several kinds of protein-displaying yeasts have been utilized as bioadsorbents in this platform technology. In particular, these trials have successfully expanded the possibility of applications to metal binding, affinity purification, and receptor-ligand interaction by using the yeast cell surface. In this mini review, we describe the general principles of molecular display technology using yeast cells and its applications, with a particular focus on bioadsorption.

  14. Probiotic Properties of Non-Saccharomyces Yeasts

    DEFF Research Database (Denmark)

    Smith, Ida Mosbech

    to harmless luminal substances is a key feature of the intestinal immune system. In this context, dendritic cells (DCs) present in the tissues lining the human gut are central players involved in microbial sensing and shaping of appropriate adaptive immune responses. Probiotics are live microorganisms which...... when administered in adequate amounts confer a health benefit on the host. While the majority of probiotic microorganisms studied to date are lactic acid bacteria, research in yeasts with potentially beneficial influences on human health has mainly revolved around Saccharomyces boulardii. This yeast...... has shown a positive impact on disease outcome in clinical studies of inflammatory bowel disease, indicating an ability of S. boulardii to influence human immune responses underlying intestinal inflammation. Consequent to this focus on S. boulardii as the fundamental probiotic yeast, very little...

  15. Yeasts and yeast-like organisms associated with fruits and blossoms of different fruit trees.

    Science.gov (United States)

    Vadkertiová, Renáta; Molnárová, Jana; Vránová, Dana; Sláviková, Elena

    2012-12-01

    Yeasts are common inhabitants of the phyllosphere, but our knowledge of their diversity in various plant organs is still limited. This study focused on the diversity of yeasts and yeast-like organisms associated with matured fruits and fully open blossoms of apple, plum, and pear trees, during 2 consecutive years at 3 localities in southwest Slovakia. The occurrence of yeasts and yeast-like organisms in fruit samples was 2½ times higher and the yeast community more diverse than that in blossom samples. Only 2 species (Aureobasidium pullulans and Metschnikowia pulcherrima) occurred regularly in the blossom samples, whereas Galactomyces candidus, Hanseniaspora guilliermondii, Hanseniaspora uvarum, M. pulcherrima, Pichia kluyveri, Pichia kudriavzevii, and Saccharomyces cerevisiae were the most frequently isolated species from the fruit samples. The ratio of the number of samples where only individual species were present to the number of samples where 2 or more species were found (consortium) was counted. The occurrence of individual species in comparison with consortia was much higher in blossom samples than in fruit samples. In the latter, consortia predominated. Aureobasidium pullulans, M. pulcherrima, and S. cerevisiae, isolated from both the fruits and blossoms, can be considered as resident yeast species of various fruit tree species cultivated in southwest Slovakia localities.

  16. ISOLATION OF PROTEOLYTIC PSYCHROTROPHIC YEASTS FROM FRESH RAW SEAFOODS

    NARCIS (Netherlands)

    KOBATAKE, M; KREGERVANRIJ, NJW; PLACIDO, MTLC; VANUDEN, N

    A total of 103 cultures of yeasts were isolated from seven kinds of fresh raw seafoods. The isolates comprised six genera, Candida, Cryptococcus, Debaryomyces. Rhodotorula, Sterigmatomyces and Trichosporon, and included 21 different species. All the isolates were psychrotrophic yeasts. Proteolytic

  17. Autophagy: one more Nobel Prize for yeast

    Directory of Open Access Journals (Sweden)

    Andreas Zimmermann

    2016-12-01

    Full Text Available The recent announcement of the 2016 Nobel Prize in Physiology or Medicine, awarded to Yoshinori Ohsumi for the discoveries of mechanisms governing autophagy, underscores the importance of intracellular degradation and recycling. At the same time, it further cements yeast, in which this field decisively developed, as a prolific model organism. Here we provide a quick historical overview that mirrors both the importance of autophagy as a conserved and essential process for cellular life and death as well as the crucial role of yeast in its mechanistic characterization.

  18. Autophagy: one more Nobel Prize for yeast.

    Science.gov (United States)

    Zimmermann, Andreas; Kainz, Katharina; Andryushkova, Aleksandra; Hofer, Sebastian; Madeo, Frank; Carmona-Gutierrez, Didac

    2016-12-05

    The recent announcement of the 2016 Nobel Prize in Physiology or Medicine, awarded to Yoshinori Ohsumi for the discoveries of mechanisms governing autophagy, underscores the importance of intracellular degradation and recycling. At the same time, it further cements yeast, in which this field decisively developed, as a prolific model organism. Here we provide a quick historical overview that mirrors both the importance of autophagy as a conserved and essential process for cellular life and death as well as the crucial role of yeast in its mechanistic characterization.

  19. Flux control through protein phosphorylation in yeast

    DEFF Research Database (Denmark)

    Chen, Yu; Nielsen, Jens

    2016-01-01

    Protein phosphorylation is one of the most important mechanisms regulating metabolism as it can directly modify metabolic enzymes by the addition of phosphate groups. Attributed to such a rapid and reversible mechanism, cells can adjust metabolism rapidly in response to temporal changes. The yeast...... describe the development of phosphoproteomics in yeast as well as approaches to analysing the phosphoproteomics data. Finally, we focus on integrated analyses with other omics data sets and genome-scale metabolic models. Despite the advances, future studies improving both experimental technologies...

  20. Analysis of RNA metabolism in fission yeast

    DEFF Research Database (Denmark)

    Wise, Jo Ann; Nielsen, Olaf

    2017-01-01

    Here we focus on the biogenesis and function of messenger RNA (mRNA) in fission yeast cells. Following a general introduction that also briefly touches on other classes of RNA, we provide an overview of methods used to analyze mRNAs throughout their life cycles.......Here we focus on the biogenesis and function of messenger RNA (mRNA) in fission yeast cells. Following a general introduction that also briefly touches on other classes of RNA, we provide an overview of methods used to analyze mRNAs throughout their life cycles....

  1. DNA replication in yeast is stochastic

    Science.gov (United States)

    Cheng-Hsin Yang, Scott; Rhind, Nicholas; Bechhoefer, John

    2010-03-01

    Largely on the basis of a simple --- perhaps too simple --- analysis of microarray-chip experiments, people have concluded that DNA replication in budding yeast (S. cerevisiae) is a nearly deterministic process, in which the position and activation time of each origin of replication is pre-determined. In this talk, we introduce a more quantitative approach to the analysis of microarray data. Applying our new methods to budding yeast, we show that the microarray data imply a picture of replication where the timing of origin activation is highly stochastic. We then propose a physical model (the ``multiple-initiator model") to account for the observed probability distributions of origin- activation timing.

  2. Overwintering of vineyard yeasts: survival of interacting yeast communities in grapes mummified on vines

    Directory of Open Access Journals (Sweden)

    Matthias eSipiczki

    2016-02-01

    Full Text Available The conversion of grape must into wine involves the development and succession of yeast populations differing in species composition. The initial population is formed by vineyard strains which are washed into the must from the crushed grapes and then completed with yeasts coming from the cellar environment. As the origin and natural habitat of the vineyard yeasts are not fully understood, this study addresses the possibility that grape yeasts can be preserved in berries left behind on vines at harvest until the spring of the next year. These berries become mummified during the winter on the vines. To investigate whether yeasts can survive in these overwintering grapes, mummified berries were collected in 16 localities in the Tokaj wine region (Hungary-Slovakia in early March. The collected berries were rehydrated to recover viable yeasts by plating samples onto agar plates. For the detection of minority species which would not be detected by direct plating, an enrichment step repressing the propagation of alcohol-sensitive yeasts was also included in the process. The morphological, physiological and molecular analysis identified 13 basidiomycetous and 23 ascomycetous species including fermentative yeasts of wine-making relevance among the 3879 isolates. The presence of viable strains of these species demonstrates that the grapes mummified on the vine can serve as a safe reservoir of yeasts, and may contribute to the maintenance of grape-colonizing yeast populations in the vineyard over years, parallel with other vectors and habitats. All basidiomycetous species were known phylloplane yeasts. Three Hanseniaspora species and pigmented Metschnikowia strains were the most frequent ascomycetes. Other fermentative yeasts of wine-making relevance were detected only in the enrichment cultures. Saccharomyces (S. paradoxus, S. cerevisiae and S. uvarum were recovered from 13 % of the samples. No Candida zemplinina was found. The isolates with Aureobasidium

  3. Occurrence of Killer Yeast Strains in Fruit and Berry Wine Yeast Populations

    Directory of Open Access Journals (Sweden)

    Gintare Gulbiniene

    2004-01-01

    Full Text Available Apple, cranberry, chokeberry and Lithuanian red grape wine yeast populations were used for the determination of killer yeast occurrence. According to the tests of the killer characteristics and immunity the isolated strains were divided into seven groups. In this work the activity of killer toxins purified from some typical strains was evaluated. The analysed strains produced different amounts of active killer toxin and some of them possessed new industrially significant killer properties. Total dsRNA extractions in 11 killer strains of yeast isolated from spontaneous fermentations revealed that the molecular basis of the killer phenomenon was not only dsRNAs, but also unidentified genetic determinants.

  4. Newly identified prions in budding yeast, and their possible functions

    OpenAIRE

    Crow, Emily T.; Li, Liming

    2011-01-01

    Yeast prions are atypical genetic elements that are transmitted as heritable protein conformations. [PSI+], [URE3], and [PIN+] are three well-studied prions in the budding yeast, Saccharomyces cerevisiae. In the last three years, several additional prions have been reported in yeast, including [SWI+], [OCT+], [MCA], [GAR+], [MOT3+], [ISP+], and [NSI+]. The growing number of yeast prions suggests that protein-based inheritance might be a widespread biological phenomenon. In this review, we sum...

  5. Effect of increasing growth temperature on yeast fermentation ...

    African Journals Online (AJOL)

    The effect of increasing growth temperature on yeast fermentation was studied at approximately 5 oC intervals over a range of 18 – 37 oC, using one strain each of ale, lager and wine yeast. The ale and wine yeasts grew at all the temperatures tested, but lager yeast failed to grow at 37 oC. All these strains gave lower ...

  6. Differential Adsorption of Ochratoxin A and Anthocyanins by Inactivated Yeasts and Yeast Cell Walls during Simulation of Wine Aging

    National Research Council Canada - National Science Library

    Petruzzi, Leonardo; Baiano, Antonietta; De Gianni, Antonio; Sinigaglia, Milena; Corbo, Maria Rosaria; Bevilacqua, Antonio

    2015-01-01

    The adsorption of ochratoxin A (OTA) by yeasts is a promising approach for the decontamination of musts and wines, but some potential competitive or interactive phenomena between mycotoxin, yeast cells, and anthocyanins might modify...

  7. Drosophila-associated yeast species in vineyard ecosystems.

    Science.gov (United States)

    Lam, Samuel S T H; Howell, Kate S

    2015-10-01

    Yeast activity during wine fermentation directly contributes to wine quality, but the source and movement of yeasts in vineyards and winery environments have not been resolved. Here, we investigate the yeast species associated with the Drosophila insect vector to help understand yeast dispersal and persistence. Drosophila are commonly found in vineyards and are known to have a mutualistic relationship with yeasts in other ecosystems. Drosophilids were collected from vineyards, grape waste (marc) piles and wineries during grape harvest. Captured flies were identified morphologically, and their associated yeasts were identified. Drosophila melanogaster/D. simulans, D. hydei and Scaptodrosophila lativittata were identified in 296 captured Drosophila flies. These flies were associated with Metschnikowia pulcherrima, Hanseniaspora uvarum, Torulaspora delbrueckii and H. valbyensis yeasts. Yeast and Drosophila species diversity differed between collection locations (vineyard and marc: R = 0.588 for Drosophila and R = 0.644 for yeasts). Surprisingly, the primary wine fermentation yeast, Saccharomyces cerevisiae, was not isolated. Drosophila flies are preferentially associated with different yeast species in the vineyard and winery environments, and this association may help the movement and dispersal of yeast species in the vineyard and winery ecosystem. © FEMS 2015. All rights reserved.

  8. Performance of baker's yeast produced using date syrup substrate ...

    African Journals Online (AJOL)

    Baker's yeast was produced from three selected baker's yeast strains using date syrup as a substrate at low and high flow rate compared to those produced using molasses substrates. Performance of the produced baker's yeasts on Arabic bread quality was investigated. Baking tests showed a positive relationship between ...

  9. Effect of yeast extract and chitosan on shoot proliferation ...

    African Journals Online (AJOL)

    This paper reported the effect of yeast extract and chitosan with combination of yeast extract on the growth and morphological changes and production of phenolics in the in vitro plantlets of Curcuma mangga. Yeast extract did not show any effect on the biomass and shoot proliferation of in vitro plantlets. However, the ...

  10. Effects of chlorine and temperature on yeasts isolatedfrom a soft ...

    African Journals Online (AJOL)

    Yeasts isolated from sugar and filling valves in a bottling process were exposed to different chlorine concentrations and various high temperatures. It was found that growth of yeasts decreased with increase in chlorine concentration. The maximum chlorine concentration that inhibited both types of yeasts was 60mg/l while ...

  11. Bright stable luminescent yeast using bacterial luciferase as a sensor.

    NARCIS (Netherlands)

    Szittner, R; Jansen, G.; Thomas, DY; Meighen, E

    2003-01-01

    24h while luminescence of yeast with decanal decayed to less than 0.01% of that with Z-9-tetradecenal after 2min. Moreover, yeast survived in 0.5% (v/v) Z-9-tetradecenal while 0.005% (v/v) decanal was lethal. Luminescence of yeast (+luxAB) was also stimulated 100-fold by transformation with the

  12. Screening of yeasts capable of producing cellulase-free xylanase

    African Journals Online (AJOL)

    Professor

    2015-06-10

    Jun 10, 2015 ... medium and the enzymatic activities of endo-xylanase, β-xylosidase, carboxymetilcellulase, and filter paper cellulose ... yeasts, parts of the fruits and vegetables (stems, leaves, roots) were evaluated separately. Yeast isolation. For enrichment, about 2.5 g of each sample was inoculated into. 25 mL yeast ...

  13. (FOS)-fermenting yeast or bacterial strains as potential

    African Journals Online (AJOL)

    ltrujillo

    or solid growth medium containing these “prebiotic” ... Saccharomyces cerevisiae L/25-7-82, S. cerevisiae L/25-7-76, ... Culture media. The commonly used minimal Yeast Nitrogen base (YNB) and rich media YP (Yeast extract and Peptone) and LB (Luria Bertani) for yeast and bacterial grow, respectively, were prepared ...

  14. Quality evaluation of some commercial baker's yeasts in Nigeria ...

    African Journals Online (AJOL)

    Seven different brands of commercial baker's yeast commonly found in Nigerian markets were evaluated for their acidity, viability and leavening activity. The baking and staling qualities of bread produced using the yeasts were also determined. Acidity and viability of yeast cells in the samples ranged from 2.09 to 2.78 and ...

  15. Phenotypic characters of yeasts isolated from kpete-kpete, a ...

    African Journals Online (AJOL)

    USER

    2015-07-08

    Jul 8, 2015 ... Key words: Sorghum beer, tchoukoutou, kpete-kpete, yeast, Saccharomyces cerevisiae. INTRODUCTION. Fermented .... Physicochemical and microbiological characteristics of the traditional starter kpete-kpete. Samples origin. Yeasts ... Phenotypic characteristics of yeasts isolates. Results (Table 2) show ...

  16. Yeast Contamination Potential in a Carbonated Soft Drink Industry ...

    African Journals Online (AJOL)

    MICHAEL

    species of Saccharomyces cerevisiae (Thrall, 2004). Yeasts are useful in bakery and breweries but undesirable in carbonated soft drink industries due to ... characteristics compared to yeast colonies described in Cheesebrough (1985). RESULTS AND DISCUSSION. The yeasts isolated had some budding cells. The.

  17. 21 CFR 172.590 - Yeast-malt sprout extract.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Yeast-malt sprout extract. 172.590 Section 172.590... CONSUMPTION Flavoring Agents and Related Substances § 172.590 Yeast-malt sprout extract. Yeast-malt sprout extract, as described in this section, may be safely used in food in accordance with the following...

  18. 21 CFR 184.1983 - Bakers yeast extract.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Bakers yeast extract. 184.1983 Section 184.1983 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) FOOD... Listing of Specific Substances Affirmed as GRAS § 184.1983 Bakers yeast extract. (a) Bakers yeast extract...

  19. 21 CFR 573.750 - Pichia pastoris dried yeast.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Pichia pastoris dried yeast. 573.750 Section 573... Food Additive Listing § 573.750 Pichia pastoris dried yeast. (a) Identity. The food additive Pichia pastoris dried yeast may be used in feed formulations of broiler chickens as a source of protein not to...

  20. Yeast Interacting Proteins Database: YDR357C, YGL079W [Yeast Interacting Proteins Database

    Lifescience Database Archive (English)

    Full Text Available izes to the endosome; identified as a transcriptional activator in a high-throughpu...ome; identified as a transcriptional activator in a high-throughput yeast one-hybrid assay Rows with this pr

  1. Yeast Interacting Proteins Database: YFR015C, YLR258W [Yeast Interacting Proteins Database

    Lifescience Database Archive (English)

    Full Text Available yeast homolog; expression induced by glucose limitation, nitrogen starvation, environmental stress, and entr...; expression induced by glucose limitation, nitrogen starvation, environmental stress, and entry into statio

  2. Yeast Interacting Proteins Database: YFR015C, YJL137C [Yeast Interacting Proteins Database

    Lifescience Database Archive (English)

    Full Text Available yeast homolog; expression induced by glucose limitation, nitrogen starvation, environmental stress, and entr...pression induced by glucose limitation, nitrogen starvation, environmental stress, and entry into stationary

  3. Optimization of yeast ( Saccharomyces cerevisiae ) RNA isolation ...

    African Journals Online (AJOL)

    Quality of the starting RNA is indispensably important for obtaining highly reproducible quantitative polymerase chain reaction (qPCR) and microarray results for all organisms as well as S. cerevisiae. Isolating RNA from yeast cells with a maximum quality was especially critical since these cells were rich in polysaccharides ...

  4. Glucose and the ATP paradox in yeast.

    NARCIS (Netherlands)

    Somsen, O.J.G.; Hoeben, M.A.; Esgalhado, M.E.L.M.; Snoep, J.L.; Visser, D.; van der Heijden, R.T.J.M.; Heijnen, J.J.; Westerhoff, H.V.

    2000-01-01

    A sustained decrease in the intracellular ATP concentration has been observed when extra glucose was added to yeast cells growing aerobically under glucose limitation. Because glucose degradation is the main source of ATP-derived free energy, this is a counter-intuitive phenomenon, which cannot be

  5. Cell biology of homologous recombination in yeast

    DEFF Research Database (Denmark)

    Eckert-Boulet, Nadine Valerie; Rothstein, Rodney; Lisby, Michael

    2011-01-01

    Homologous recombination is an important pathway for error-free repair of DNA lesions, such as single- and double-strand breaks, and for rescue of collapsed replication forks. Here, we describe protocols for live cell imaging of single-lesion recombination events in the yeast Saccharomyces...

  6. Biofuels. Altered sterol composition renders yeast thermotolerant

    DEFF Research Database (Denmark)

    Caspeta, Luis; Chen, Yun; Ghiaci, Payam

    2014-01-01

    adaptive laboratory evolution to select yeast strains with improved growth and ethanol production at ≥40°C. Sequencing of the whole genome, genome-wide gene expression, and metabolic-flux analyses revealed a change in sterol composition, from ergosterol to fecosterol, caused by mutations in the C-5 sterol...

  7. Cell polarity: wanderful exploration in yeast sex.

    Science.gov (United States)

    Arkowitz, Robert A

    2013-01-07

    Chemical gradients are used by cells to provide positional information. Two new studies reveal that polarity proteins are highly dynamic in yeast cells responding to a pheromone gradient and suggest that this behavior is important for robust directional growth. Copyright © 2013 Elsevier Ltd. All rights reserved.

  8. Uncommon opportunistic yeast bloodstream infections from Qatar

    NARCIS (Netherlands)

    Taj-Aldeen, S.J.; AbdulWahab, A.; Kolecka, A.; Deshmukh, A.; Meis, J.F.G.M.; Boekhout, T.

    2014-01-01

    Eleven uncommon yeast species that are associated with high mortality rates irrespective of antifungal therapy were isolated from 17/187 (201 episodes) pediatric and elderly patients with fungemia from Qatar. The samples were taken over a 6-year period (January 2004-December 2010). Isolated species

  9. yeast transformation of Mucor circinelloides Tieghe

    African Journals Online (AJOL)

    GRACE

    2006-05-02

    May 2, 2006 ... In a study monitored at 24 h intervals, profiling gave 2-phase expression in some treatments and this was ..... observed in the broths, although minimal in contrast to the observation in the 2- phase growth pattern described in ... Microscopic examination showed that the morphology of note was the yeast form ...

  10. Deoxyribonucleic Acid Base Composition in Yeasts

    Science.gov (United States)

    Meyer, Sally A.; Phaff, H. J.

    1969-01-01

    The deoxyribonucleic acid base composition of 15 species of yeasts was determined to obtain further clues to or supporting evidence for their taxonomic position. Species examined belonged to the genera Saccharomyces, Debaryomyces, Lodderomyces, Metschnikowia, and Candida. The range of moles per cent guanine plus cytosine (GC content) for all yeasts examined extended from 34.9 to 48.3%. The sporogenous species and the asporogenous yeasts spanned the range with 36.6 to 48.3% GC and 34.9 to 48% GC, respectively. Three Saccharomyces species (S. rosei and related species) exhibited significantly higher GC contents than S. cerevisiae, whereas the fermentative species D. globosus revealed a%GC more aligned to the S. rosei group than to the nonfermentative D. hansenii. Similar GC contents were demonstrated by L. elongasporus and its proposed imperfect form C. parapsilosis. The range of GC contents of various strains of three Metschnikowia species studied was 6.1%, with the type strain of M. pulcherrima having the highest GC content (48.3%) of all of the yeasts examined. PMID:5764346

  11. The glucose signaling network in yeast

    Science.gov (United States)

    Kim, Jeong-Ho; Roy, Adhiraj; Jouandot, David; Cho, Kyu Hong

    2013-01-01

    Background Most cells possess a sophisticated mechanism for sensing glucose and responsing to it appropriately. Glucose sensing and signaling in the budding yeast Saccharomyces cerevisiae represents an important paradigm for understanding how extracellular signals lead to changes in the gene expression program in eukaryotes. Scope of review This review focuses on the yeast glucose sensing and signaling pathways that operate in a highly regulated and cooperative manner to bring about glucose-induction of HXT gene expression. Major conclusions The yeast cells possess a family of glucose transporters (HXTs), with different kinetic properties. They employ three major glucose signaling pathways— Rgt2/Snf3, AMPK, and cAMP-PKA—to express only those transporters best suited for the amounts of glucose available. We discuss the current understanding of how these pathways are integrated into a regulatory network to ensure efficient uptake and utilization of glucose. General significance Elucidating the role of multiple glucose signals and pathways involved in glucose uptake and metabolism in yeast may reveal the molecular basis of glucose homeostasis in humans, especially under pathological conditions, such as hyperglycemia in diabetics and the elevated rate of glycolysis observed in many solid tumors. PMID:23911748

  12. UBA domain containing proteins in fission yeast

    DEFF Research Database (Denmark)

    Hartmann-Petersen, Rasmus; Semple, Colin A M; Ponting, Chris P

    2003-01-01

    characterised on both the functional and structural levels. One example of a widespread ubiquitin binding module is the ubiquitin associated (UBA) domain. Here, we discuss the approximately 15 UBA domain containing proteins encoded in the relatively small genome of the fission yeast Schizosaccharomyces pombe...

  13. Yeast metabolic engineering for hemicellulosic ethanol production

    Science.gov (United States)

    Jennifer Van Vleet; Thomas W. Jeffries

    2009-01-01

    Efficient fermentation of hemicellulosic sugars is critical for the bioconversion of lignocellulosics to ethanol. Efficient sugar uptake through the heterologous expression of yeast and fungal xylose/glucose transporters can improve fermentation if other metabolic steps are not rate limiting. Rectification of cofactor imbalances through heterologous expression of...

  14. Arachidonic acid metabolites in pathogenic yeasts

    Directory of Open Access Journals (Sweden)

    Ells Ruan

    2012-08-01

    Full Text Available Abstract Although most of what is known about the biology and function of arachidonic acid metabolites comes from the study of mammalian biology, these compounds can also be produced by lower eukaryotes, including yeasts and other fungi. It is also in this group of organisms that the least is known about the metabolic pathways leading to the production of these compounds as well as the functions of these compounds in the biology of fungi and yeasts. This review will deal with the discovery of oxylipins from polyunsaturated fatty acids, and more specifically the arachidonic acid derived eicosanoids, such as 3-hydroxy eicosatetraenoic acid, prostaglandin F2α and prostaglandin E2, in yeasts starting in the early 1990s. This review will also focus on what is known about the metabolic pathways and/or proteins involved in the production of these compounds in pathogenic yeasts. The possible roles of these compounds in the biology, including the pathology, of these organisms will be discussed.

  15. Antarctic Yeasts: Biodiversity and Potential Applications

    Science.gov (United States)

    Shivaji, S.; Prasad, G. S.

    This review is an attempt in cataloguing the diversity of yeasts in Antarctica, highlight their biotechnological potential and understand the basis of adaptation to low temperature. As of now several psychrophilic and psychrotolerant yeasts from Antarctic soils and marine waters have been characterized with respect to their growth characteristics, ecological distribution and taxonomic significance. Interestingly most of these species belonged to basidiomycetous yeasts which as a group are known for their ability to circumvent and survive under stress conditions. Simultaneously their possible role as work horses in the biotechnological industry was recognized due to their ability to produce novel enzymes and biomolecules such as agents for the breakdown of xenobiotics, and novel pharmaceutical chemi cals. The high activity of psychrophilic enzymes at low and moderate temperatures offers potential economic benefits. As of now lipases from Pseudozyma antarctica have been extensively studied to understand their unique thermal stability at 90°C and also because of its use in the pharmaceutical, agriculture, food, cosmetics and chemical industry. A few of the other enzymes which have been studied include extracellular alpha-amylase and glucoamylase from the yeast Pseudozyma antarctica (Candida antarctica), an extra-cellular protease from Cryptococcus humicola, an aspartyl proteinase from Cryptococcus humicola, a novel extracellular subtilase from Leucosporidium antarcticum, and a xylanase from Cryptococcus adeliensis

  16. Actin and Endocytosis in Budding Yeast

    Science.gov (United States)

    Goode, Bruce L.; Eskin, Julian A.; Wendland, Beverly

    2015-01-01

    Endocytosis, the process whereby the plasma membrane invaginates to form vesicles, is essential for bringing many substances into the cell and for membrane turnover. The mechanism driving clathrin-mediated endocytosis (CME) involves > 50 different protein components assembling at a single location on the plasma membrane in a temporally ordered and hierarchal pathway. These proteins perform precisely choreographed steps that promote receptor recognition and clustering, membrane remodeling, and force-generating actin-filament assembly and turnover to drive membrane invagination and vesicle scission. Many critical aspects of the CME mechanism are conserved from yeast to mammals and were first elucidated in yeast, demonstrating that it is a powerful system for studying endocytosis. In this review, we describe our current mechanistic understanding of each step in the process of yeast CME, and the essential roles played by actin polymerization at these sites, while providing a historical perspective of how the landscape has changed since the preceding version of the YeastBook was published 17 years ago (1997). Finally, we discuss the key unresolved issues and where future studies might be headed. PMID:25657349

  17. Vaginal yeast infections in diabetic women

    African Journals Online (AJOL)

    The overall vaginal prevalence of C. albicans was 12,8% (26/203 patients). This yeast was associated with genital symp- toms in 84,6% (22/26) ofthe patients from whom it was isolated. Only 4 patients without symptoms yielded C. albicans. One of these had classic candidiasis on clinical grounds, while the other 3 patients ...

  18. Localization of some phosphatases in yeast

    NARCIS (Netherlands)

    Tonino, G.J.M.; Steyn-Parvé, Elizabeth P.

    1963-01-01

    1. 1. The localization of some phosphatases has been studied in yeast cells that were either fragmented by shaking intact cells with glass beads or by hypotonic or isotonic disruption of protoplasts prepared from intact cells. 2. 2. The non-specific acid phosphatase with optimum activity at pH

  19. Developmentally programmed nuclear destruction during yeast gametogenesis.

    Science.gov (United States)

    Eastwood, Michael D; Cheung, Sally W T; Lee, Kwan Yin; Moffat, Jason; Meneghini, Marc D

    2012-07-17

    Autophagy controls cellular catabolism in diverse eukaryotes and modulates programmed cell death in plants and animals. While studies of the unicellular yeast Saccharomyces cerevisiae have provided fundamental insights into the mechanisms of autophagy, the roles of cell death pathways in yeast are less well understood. Here, we describe widespread developmentally programmed nuclear destruction (PND) events that occur during yeast gametogenesis. PND is executed through apoptotic-like DNA fragmentation in coordination with an unusual form of autophagy that is most similar to mammalian lysosomal membrane permeabilization and mega-autophagy, a form of plant autophagic cell death. Undomesticated strains execute gametogenic PND broadly in maturing colonies to the apparent benefit of sibling cells, confirming its prominence during the yeast life cycle. Our results reveal that diverse cell-death-related processes converge during gametogenesis in a microbe distantly related to plants or animals, highlighting gametogenesis as a process during which programmed cell death mechanisms may have evolved. Copyright © 2012 Elsevier Inc. All rights reserved.

  20. Modeling diauxic glycolytic oscillations in yeast

    DEFF Research Database (Denmark)

    Hald, Bjørn Olav; Sørensen, Preben Graae

    2010-01-01

    Glycolytic oscillations in a stirred suspension of starved yeast cells is an excellent model system for studying the dynamics of metabolic switching in living systems. In an open-flow system the oscillations can be maintained indefinitely at a constant operating point where they can be characteri...

  1. Vaginal yeast infections in diabetic women

    African Journals Online (AJOL)

    could we implicate either trichomoniasis or candidiasis as causes ofthese symptoms (Table I). It is possible that in some instances yeasts may have been missed on cul- ture since it has been estimated that at least 10' cfu/m! are required for a culture to be positive.15 Gardnerella vaginalis was not sought in this study and ...

  2. Characteristics of fermentation yeast isolated from traditional ...

    African Journals Online (AJOL)

    Indigenous honey wine, known locally as ogol, was collected in a village of the Majangir ethnic group in Southwest Ethiopia, and the procedure for ogol fermentation was investigated. A fermentation yeast was first isolated from ogol and identified as being a strain of the genus Saccharomyces cerevisiae. Honey wine made ...

  3. Ureohydrolases as dominant selectable markers in yeast

    NARCIS (Netherlands)

    Daran, J.G.; Pronk, J.T.; Romagnoli, G.

    2015-01-01

    The invention relates to a nucleic acid molecule encoding a novel selection marker. Said marker is a guanidinobutyrase from Kluyveromyces lactis, which, when expressed in Saccharomyces, allows the growth of the yeast in the presence of guanidinobutyrate as the sole nitrogen source. Said marker can

  4. Functional differences in yeast protein disulfide isomerases

    DEFF Research Database (Denmark)

    Nørgaard, P; Westphal, V; Tachibana, C

    2001-01-01

    PDI1 is the essential gene encoding protein disulfide isomerase in yeast. The Saccharomyces cerevisiae genome, however, contains four other nonessential genes with homology to PDI1: MPD1, MPD2, EUG1, and EPS1. We have investigated the effects of simultaneous deletions of these genes. In several c...

  5. Biosynthesis of polyhydroxyalkanotes in wildtype yeasts 1 ...

    African Journals Online (AJOL)

    MICHAEL

    Valentin. 1995). The major commercial drawback of the so-produced bacterial PHAs is their high production cost, making them substantially more expensive than synthetic plastics (Poirier et al. 1995). Therefore, looking for eukaryotic cell systems like yeast able to accumulate. PHAs seems to be a beneficial alternative to the.

  6. Effect of yeast storage temperature and flour composition on fermentative activities of baker's yeast

    Directory of Open Access Journals (Sweden)

    Pejin Dušanka J.

    2009-01-01

    Full Text Available Baker's yeast is a set of living cells of Saccharomyces cerevisiae. It contains around 70-72% of water, 42-45% of proteins, around 40% of carbohydrates, around 7.5% of lipids (based on dry matter, and vitamin B-complex. On the basis of yeast cell analysis it can be concluded that yeast is a complex biological system which changes in time. The intensity of the changes depends on temperature. Yeast sample was stored at 4°C i 24°C for 12 days. During storage at 4°C, the content of total carbohydrates decreased from 48.81% to 37.50% (dry matter, whereas carbohydrate loss ranged from 40.81% to 29.28% at 24°C. The content of trehalose was 12.33% in the yeast sample stored at 4°C and 0.24% at 24°C. Loss of fermentative activity was 81.76% in the sample stored at 24°C for 12 days. The composition of five samples of 1st category flour was investigated. It was found that flours containing more reducing sugars and maltose enable higher fermentation activities. The flours with higher ash content (in the range 0.5-0.94% had higher contents of phytic acid. Higher ash and phytic contents in flour increased the yeast fermentative efficiency. In bakery industry, a range of ingredients has been applied to improve the product's quality such as surface active substances (emulsifiers, enzymes, sugars and fats. In the paper, the effect of some ingredients added to dough (margarine, saccharose, sodium chloride and malted barley on the yeast fermentative activity was studied. The mentioned ingredients were added to dough at different doses: 0.5, 1.0, 1.5 and 2.0%, flour basis. It was found that the investigated ingredients affected the fermentative activity of yeast and improved the bread quality.

  7. Killer yeasts as biocontrol agents of spoilage yeasts and bacteria isolated from wine

    Directory of Open Access Journals (Sweden)

    Fernández de Ullivarri Miguel

    2014-01-01

    Full Text Available During the winemaking process Saccharomyces cerevisiae is the main yeast species but other yeasts called non-Saccharomyces as well as different species of lactic acid bacteria (LAB are also present. Then, one strategy to prevent or reduce microbial contamination during the winemaking process is the use of killer yeasts. The aim of this study was to evaluate the killer activity (KA of autochthonous yeasts from Northwest region of Argentine (S. cerevisiae Cf8 and Wickerhamomyces anomalus Cf20 on spoilage yeasts and in LAB of the wine. The KA was evaluated using cell-free supernatants obtained from pure and mixed cultures of strains Cf8-Cf20. S. cerevisiae Cf8 showed a growth reduction between 7 and 48% on D. anomala BDa15, P. membranifaciens BPm481 and Z. bailii Bzb317 while W. anomalus Cf20 exhibited KA of 20, 61, 91 and 92% against B. bruxellensis Ld1, D. anomala BDa15, P. membranifaciens BPm481 and P. guilliermondii Cd6, respectively. Killer mixed supernatants showed growth inhibition similar to strain Cf20. Screening against LAB showed that both killer toxins were able to inhibit the growth of L. hilgardii 5w as well as to reduce a 16–31% histamine production by this LAB strain. These results confirm the potential of autochthonous killer yeasts as biocontrol agents in winemaking process. The mixed culture S. cerevisiae Cf8-W. anomalus Cf20 presented a wide range of KA on spoilage yeasts as well as on L. hilgardii. Therefore, the use of killer yeasts as starter cultures would allow producing wines with controlled quality.

  8. DETERMINATION OF KILLER CHARACTER OF WINE YEAST ISOLATED FROM ISTRA

    Directory of Open Access Journals (Sweden)

    Sandi ORLIC

    2008-07-01

    Full Text Available Wild wine yeasts with killer phenotype are widespread in many wine regions of the world. The presence of killer yeasts may become particularly important in wine fermentations conducted by inoculation with selected strains of Saccharomyces cerevisiae. Wild killer yeasts may suppress selected sensitive yeasts inoculated into the must during the fermentation. The goal of this investigation was to identify killer yeast in Istra region using physiological and molecular methods. In total 50 S.cerevisiae strains were tested. Using the physiological methods 17 strains were identifi ed like killer positive and using molecular methods two strains more. Our results are in agreement with some previous ecological surveys.

  9. Inventions on baker's yeast strains and specialty ingredients.

    Science.gov (United States)

    Gélinas, Pierre

    2009-06-01

    Baker's yeast is one of the oldest food microbial starters. Between 1927 and 2008, 165 inventions on more than 337 baker's yeast strains were patented. The first generation of patented yeast strains claimed improved biomass yield at the yeast plant, higher gassing power in dough or better survival to drying to prepare active dry baker's yeast. Especially between 1980 and 1995, a major interest was given to strains for multiple bakery applications such as dough with variable sugar content and stored at refrigeration (cold) or freezing temperatures. During the same period, genetically engineered yeast strains became very popular but did not find applications in the baking industry. Since year 2000, patented baker's yeast strains claimed aroma, anti-moulding or nutritive properties to better meet the needs of the baking industry. In addition to patents on yeast strains, 47 patents were issued on baker's yeast specialty ingredients for niche markets. This review shows that patents on baker's yeast with improved characteristics such as aromatic or nutritive properties have regularly been issued since the 1920's. Overall, it also confirms recent interest for a very wide range of tailored-made yeast-based ingredients for bakery applications.

  10. The Role of Magnesium and Calcium in Governing Yeast Agglomeration

    Directory of Open Access Journals (Sweden)

    Rosslyn M. Birch

    2002-01-01

    Full Text Available »Grit« formation by agglomerating cells of baker’s yeast is an idiosyncratic phenomenon of irreversible cellular aggregation that is detrimental to yeast quality. Agglomeration results in failure of rehydrated dried yeast to evenly resuspend and has economic consequences for both yeast manufacturers and bakers. Several environmental factors are implicated in governing yeast agglomeration, but no significant differences between 'gritty' and 'non-gritty' yeast in terms of cell hydrophobicity or flocculence have been reported. In this study, analysis of cellular metal ions has revealed high levels of calcium in 'gritty' strains of Saccharomyces cerevisiae, which suggests that calcium ions may positively influence agglomeration. In contrast, it was found that cellular magnesium levels were higher in 'non-gritty' yeast. Furthermore, by increasing magnesium concentrations in molasses yeast growth media, a reduction in cellular calcium was observed and this concomitantly reduced the tendency of cells to agglomerate and form grit. Magnesium thus acted antagonistically against calcium-induced agglomeration, possibly by blocking calcium binding to yeast cell surface receptors. Results suggested that yeast agglomeration and metal ion bioavailability were inextricably linked and the findings are discussed in relation to possible measures of alleviating cellular agglomeration in the production of baker’s yeast.

  11. Baker's yeast: production of D- and L-3-hydroxy esters

    DEFF Research Database (Denmark)

    Dahl, Allan Carsten; Madsen, Jørgen Øgaard

    1998-01-01

    Baker's yeast grown under oxygen limited conditions and used in the reduction of 3-oxo esters results in a shift of the stereoselectivity of the yeast towards D-hydroxy esters as compared with ordinary baker's yeast. The highest degree of stereoselectivity was obtained with growing yeast or yeast...... harvested while growing. In contrast, the stereoselectivity was shifted towards L-hydroxy esters when the oxo esters were added slowly to ordinary baker's yeast supplied with gluconolactone as co-substrate. The reduction rate with gluconolactone was increased by active aeration. Ethyl L-(S)-3......-hydroxybutanoate was afforded in >99% ee. Both enantiomers of ethyl 3-hydroxypentanoate, D-(R) in 96% ee and L-(S) in 93% ee, and of ethyl 4-chloro-3-hydroxybutanoate, D-(S) in 98% ee and L-(R) in 94% ee, were obtained. The results demonstrate that the stereoselectivity of baker's yeast can be controlled...

  12. Patulin biodegradation by marine yeast Kodameae ohmeri.

    Science.gov (United States)

    Dong, Xiaoyan; Jiang, Wei; Li, Chunsheng; Ma, Ning; Xu, Ying; Meng, Xianghong

    2015-01-01

    Patulin contamination of fruit- and vegetable-based products had become a major challenge for the food industry. Biological methods of patulin control can play an important role due to their safety and high efficiency. In this study, a strain of marine yeast with high patulin degradation ability was screened. The yeast was identified as Kodameae ohmeri by the BioLog identification system and partial 26S rRNA gene sequencing. The degradation products of patulin were identified as (E)- and (Z)-ascladiol through HPLC and LC-TOF/MS. High patulin tolerance at 100 μg ml(-1) and a high degradation rate at 35°C at a pH between 3 and 6 indicates the potential application of K. ohmeri for patulin detoxification of apple-derived products.

  13. Made for Each Other: Ascomycete Yeasts and Insects.

    Science.gov (United States)

    Blackwell, Meredith

    2017-06-01

    Fungi and insects live together in the same habitats, and many species of both groups rely on each other for success. Insects, the most successful animals on Earth, cannot produce sterols, essential vitamins, and many enzymes; fungi, often yeast-like in growth form, make up for these deficits. Fungi, however, require constantly replenished substrates because they consume the previous ones, and insects, sometimes lured by volatile fungal compounds, carry fungi directly to a similar, but fresh, habitat. Yeasts associated with insects include Ascomycota (Saccharomycotina, Pezizomycotina) and a few Basidiomycota. Beetles, homopterans, and flies are important associates of fungi, and in turn the insects carry yeasts in pits, specialized external pouches, and modified gut pockets. Some yeasts undergo sexual reproduction within the insect gut, where the genetic diversity of the population is increased, while others, well suited to their stable environment, may never mate. The range of interactions extends from dispersal of yeasts on the surface of insects (e.g., cactus- Drosophila -yeast and ephemeral flower communities, ambrosia beetles, yeasts with holdfasts) to extremely specialized associations of organisms that can no longer exist independently, as in the case of yeast-like symbionts of planthoppers. In a few cases yeast-like fungus-insect associations threaten butterflies and other species with extinction. Technical advances improve discovery and identification of the fungi but also inform our understanding of the evolution of yeast-insect symbioses, although there is much more to learn.

  14. MALDI-TOF MS as a tool to identify foodborne yeasts and yeast-like fungi.

    Science.gov (United States)

    Quintilla, Raquel; Kolecka, Anna; Casaregola, Serge; Daniel, Heide M; Houbraken, Jos; Kostrzewa, Markus; Boekhout, Teun; Groenewald, Marizeth

    2018-02-02

    Since food spoilage by yeasts causes high economic losses, fast and accurate identifications of yeasts associated with food and food-related products are important for the food industry. In this study the efficiency of the matrix assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF MS) to identify food related yeasts was evaluated. A CBS in-house MALDI-TOF MS database was created and later challenged with a blinded test set of 146 yeast strains obtained from food and food related products. Ninety eight percent of the strains were correctly identified with log score values>1.7. One strain, Mrakia frigida, gained a correct identification with a score value1.7. Ambiguous identifications were observed due to two incorrect reference mass spectra's found in the commercial database BDAL v.4.0, namely Candida sake DSM 70763 which was re-identified as Candida oleophila, and Candida inconspicua DSM 70631 which was re-identified as Pichia membranifaciens. MALDI-TOF MS can distinguish between most of the species, but for some species complexes, such as the Kazachstania telluris and Mrakia frigida complexes, MALDI-TOF MS showed limited resolution and identification of sibling species was sometimes problematic. Despite this, we showed that the MALDI-TOF MS is applicable for routine identification and validation of foodborne yeasts, but a further update of the commercial reference databases is needed. Copyright © 2017 Elsevier B.V. All rights reserved.

  15. De novo biosynthesis of vanillin in fission yeast (Schizosaccharomyces pombe) and baker's yeast (Saccharomyces cerevisiae).

    Science.gov (United States)

    Hansen, Esben H; Møller, Birger Lindberg; Kock, Gertrud R; Bünner, Camilla M; Kristensen, Charlotte; Jensen, Ole R; Okkels, Finn T; Olsen, Carl E; Motawia, Mohammed S; Hansen, Jørgen

    2009-05-01

    Vanillin is one of the world's most important flavor compounds, with a global market of 180 million dollars. Natural vanillin is derived from the cured seed pods of the vanilla orchid (Vanilla planifolia), but most of the world's vanillin is synthesized from petrochemicals or wood pulp lignins. We have established a true de novo biosynthetic pathway for vanillin production from glucose in Schizosaccharomyces pombe, also known as fission yeast or African beer yeast, as well as in baker's yeast, Saccharomyces cerevisiae. Productivities were 65 and 45 mg/liter, after introduction of three and four heterologous genes, respectively. The engineered pathways involve incorporation of 3-dehydroshikimate dehydratase from the dung mold Podospora pauciseta, an aromatic carboxylic acid reductase (ACAR) from a bacterium of the Nocardia genus, and an O-methyltransferase from Homo sapiens. In S. cerevisiae, the ACAR enzyme required activation by phosphopantetheinylation, and this was achieved by coexpression of a Corynebacterium glutamicum phosphopantetheinyl transferase. Prevention of reduction of vanillin to vanillyl alcohol was achieved by knockout of the host alcohol dehydrogenase ADH6. In S. pombe, the biosynthesis was further improved by introduction of an Arabidopsis thaliana family 1 UDP-glycosyltransferase, converting vanillin into vanillin beta-D-glucoside, which is not toxic to the yeast cells and thus may be accumulated in larger amounts. These de novo pathways represent the first examples of one-cell microbial generation of these valuable compounds from glucose. S. pombe yeast has not previously been metabolically engineered to produce any valuable, industrially scalable, white biotech commodity.

  16. Biotechnology of non-Saccharomyces yeasts-the basidiomycetes.

    Science.gov (United States)

    Johnson, Eric A

    2013-09-01

    Yeasts are the major producer of biotechnology products worldwide, exceeding production in capacity and economic revenues of other groups of industrial microorganisms. Yeasts have wide-ranging fundamental and industrial importance in scientific, food, medical, and agricultural disciplines (Fig. 1). Saccharomyces is the most important genus of yeast from fundamental and applied perspectives and has been expansively studied. Non-Saccharomyces yeasts (non-conventional yeasts) including members of the Ascomycetes and Basidiomycetes also have substantial current utility and potential applicability in biotechnology. In an earlier mini-review, "Biotechnology of non-Saccharomyces yeasts-the ascomycetes" (Johnson Appl Microb Biotechnol 97: 503-517, 2013), the extensive biotechnological utility and potential of ascomycetous yeasts are described. Ascomycetous yeasts are particularly important in food and ethanol formation, production of single-cell protein, feeds and fodder, heterologous production of proteins and enzymes, and as model and fundamental organisms for the delineation of genes and their function in mammalian and human metabolism and disease processes. In contrast, the roles of basidiomycetous yeasts in biotechnology have mainly been evaluated only in the past few decades and compared to the ascomycetous yeasts and currently have limited industrial utility. From a biotechnology perspective, the basidiomycetous yeasts are known mainly for the production of enzymes used in pharmaceutical and chemical synthesis, for production of certain classes of primary and secondary metabolites such as terpenoids and carotenoids, for aerobic catabolism of complex carbon sources, and for bioremediation of environmental pollutants and xenotoxicants. Notwithstanding, the basidiomycetous yeasts appear to have considerable potential in biotechnology owing to their catabolic utilities, formation of enzymes acting on recalcitrant substrates, and through the production of unique primary

  17. An engineered yeast efficiently secreting penicillin.

    Directory of Open Access Journals (Sweden)

    Loknath Gidijala

    Full Text Available This study aimed at developing an alternative host for the production of penicillin (PEN. As yet, the industrial production of this beta-lactam antibiotic is confined to the filamentous fungus Penicillium chrysogenum. As such, the yeast Hansenula polymorpha, a recognized producer of pharmaceuticals, represents an attractive alternative. Introduction of the P. chrysogenum gene encoding the non-ribosomal peptide synthetase (NRPS delta-(L-alpha-aminoadipyl-L-cysteinyl-D-valine synthetase (ACVS in H. polymorpha, resulted in the production of active ACVS enzyme, when co-expressed with the Bacillus subtilis sfp gene encoding a phosphopantetheinyl transferase that activated ACVS. This represents the first example of the functional expression of a non-ribosomal peptide synthetase in yeast. Co-expression with the P. chrysogenum genes encoding the cytosolic enzyme isopenicillin N synthase as well as the two peroxisomal enzymes isopenicillin N acyl transferase (IAT and phenylacetyl CoA ligase (PCL resulted in production of biologically active PEN, which was efficiently secreted. The amount of secreted PEN was similar to that produced by the original P. chrysogenum NRRL1951 strain (approx. 1 mg/L. PEN production was decreased over two-fold in a yeast strain lacking peroxisomes, indicating that the peroxisomal localization of IAT and PCL is important for efficient PEN production. The breakthroughs of this work enable exploration of new yeast-based cell factories for the production of (novel beta-lactam antibiotics as well as other natural and semi-synthetic peptides (e.g. immunosuppressive and cytostatic agents, whose production involves NRPS's.

  18. Live Cell Imaging in Fission Yeast

    OpenAIRE

    Mulvihill, Daniel P.

    2017-01-01

    Live cell imaging complements the array of biochemical and molecular genetic approaches to provide a comprehensive insight into functional dependencies and molecular interactions in fission yeast. Fluorescent proteins and vital dyes reveal dynamic changes in the spatial distribution of organelles and the proteome and how each alters in response to changes in environmental and genetic composition. This introduction discusses key issues and basic image analysis for live cell imaging of fission ...

  19. Chronological aging-induced apoptosis in yeast

    OpenAIRE

    Fabrizio, Paola; Longo, Valter D.

    2008-01-01

    Saccharomyces cerevisiae is the simplest among the major eukaryotic model organisms for aging and diseases. Longevity in the chronological life span paradigm is measured as the mean and maximum survival period of populations of non-dividing yeast. This paradigm has been used successfully to identify several life-regulatory genes and three evolutionary conserved pro-aging pathways. More recently, Schizosaccharomyces pombe has been shown to age chronologically in a manner that resembles that of...

  20. Complete biosynthesis of opioids in yeast

    OpenAIRE

    Galanie, Stephanie; Thodey, Kate; Trenchard, Isis J.; Interrante, Maria Filsinger; Smolke, Christina D.

    2015-01-01

    Opioids are the primary drugs used in Western medicine for pain management and palliative care. Farming of opium poppies remains the sole source of these essential medicines despite diverse market demands and uncertainty in crop yields due to weather, climate change, and pests. Here, we engineered yeast to produce the selected opioid compounds thebaine and hydrocodone starting from sugar. All work was conducted in a laboratory that is permitted and secured for work with controlled substances....

  1. Taxonomy Icon Data: fission yeast [Taxonomy Icon

    Lifescience Database Archive (English)

    Full Text Available fission yeast Schizosaccharomyces pombe Schizosaccharomyces_pombe_L.png Schizosaccharomy...ces_pombe_NL.png Schizosaccharomyces_pombe_S.png Schizosaccharomyces_pombe_NS.png http://biosciencedbc.jp/taxonomy..._icon/icon.cgi?i=Schizosaccharomyces+pombe&t=L http://biosciencedbc.jp/taxonomy_icon/icon.cgi?i=Schizosaccharomy...ces+pombe&t=NL http://biosciencedbc.jp/taxonomy_icon/icon.cgi?i=Schizosaccharomy...ces+pombe&t=S http://biosciencedbc.jp/taxonomy_icon/icon.cgi?i=Schizosaccharomyces+pombe&t=NS

  2. Ribosome biogenesis in the yeast Saccharomyces cerevisiae.

    Science.gov (United States)

    Woolford, John L; Baserga, Susan J

    2013-11-01

    Ribosomes are highly conserved ribonucleoprotein nanomachines that translate information in the genome to create the proteome in all cells. In yeast these complex particles contain four RNAs (>5400 nucleotides) and 79 different proteins. During the past 25 years, studies in yeast have led the way to understanding how these molecules are assembled into ribosomes in vivo. Assembly begins with transcription of ribosomal RNA in the nucleolus, where the RNA then undergoes complex pathways of folding, coupled with nucleotide modification, removal of spacer sequences, and binding to ribosomal proteins. More than 200 assembly factors and 76 small nucleolar RNAs transiently associate with assembling ribosomes, to enable their accurate and efficient construction. Following export of preribosomes from the nucleus to the cytoplasm, they undergo final stages of maturation before entering the pool of functioning ribosomes. Elaborate mechanisms exist to monitor the formation of correct structural and functional neighborhoods within ribosomes and to destroy preribosomes that fail to assemble properly. Studies of yeast ribosome biogenesis provide useful models for ribosomopathies, diseases in humans that result from failure to properly assemble ribosomes.

  3. Induction and construct UV protective yeast plasmid.

    Science.gov (United States)

    Cuero, Raul; McKay, David S

    2013-07-10

    In this study, we apply concepts of synthetic biology in combination with conventional methods to assemble different genetic components to construct yeast resistant to UV radiation, and to induce production of anti-UV proteins. This work combines sequences of different promoters, STRESS-proteins, heat shock protein (HSP), kinase proteins, alcohol dehydrogenase protein (ADH), ribosomal binding sites, fluorescent reporter proteins, terminators, and a synthetic ribosomal switch. The aim of this investigation was to induce an anti-UV proteins, and to construct an anti-UV yeast plasmid to be used for protection of skin cells against UV radiation. This investigation demonstrates induction and construction of anti-UV genes and production of their corresponding proteins. Cultures of Saccharomyces cerevisiae (ATCC # 66348) were exposed to short-wave UV radiation and were then subjected to time-PCR to assess specific gene expression. Proteins were identified using two dimensional difference gel electrophoresis (2D DIGE) and LC-MS/MS. Different up-regulated and down-regulated proteins were identified. Highly expressed identified proteins were cloned into S. cerevisiae using a synthetic biology approach. Extracts from UV-induced genetically transformed yeasts were used to protect skin cell cultures (ATCC #2522-CRL) in vitro. Both microscopic analysis and an apoptosis assay showed protection of the skin cell cultures against UV radiation. Copyright © 2013 Elsevier B.V. All rights reserved.

  4. Nanomaterials Enhanced Gene Expression in Yeast Cells

    Directory of Open Access Journals (Sweden)

    Su-Fang Chien

    2008-01-01

    Full Text Available Metal nanomaterials are shown to enhance gene expression for rice -galactosidase gene (-Gal in yeast cells. Au and Ag nanoparticles and their nanocomposites, silica-Au and silica-Ag, were prepared and characterized by UV-vis spectroscopy and TEM technique. The rice -galactosidase gene was cloned into the yeast chromosome, where the cloned cells were precultured and induced into a medium containing each of the testing nanomaterials. The nanomaterials were observed to incorporate inside the cells, and no cell death has been detected during the course of gene expression. The enzyme activity was determined by a synthetic substrate, p-nitrophenyl--D-galctopyranoside, and the yellow product yield was recorded in a spectrophotometer at 400 nm. When Au and Ag nanoparticles were incorporated with the culture, a 3–5 fold enhancement in -galactosidase was observed for intracellular activity as well as the secreted activity into the medium. The secreted protein was analyzed to have a pure form and displayed as a single protein band in the SDS-gel electrophoresis. The effects of size and chemical nature of nanomaterials on gene expression for the rice -galactosidase gene in yeast cells are discussed.

  5. Wood impregnation of yeast lees for winemaking.

    Science.gov (United States)

    Palomero, Felipe; Bertani, Paolo; Fernández de Simón, Brígida; Cadahía, Estrella; Benito, Santiago; Morata, Antonio; Suárez-Lepe, José A

    2015-03-15

    This study develops a new method to produce more complex wines by means of an indirect diffusion of wood aromas from yeast cell-walls. An exogenous lyophilized biomass was macerated with an ethanol wood extract solution and subsequently dried. Different times were used for the adsorption of polyphenols and volatile compounds to the yeast cell-walls. The analysis of polyphenols and volatile compounds (by HPLC/DAD and GC-MS, respectively) demonstrate that the adsorption/diffusion of these compounds from the wood to the yeast takes place. Red wines were also aged with Saccharomyces cerevisiae lees that had been impregnated with wood aromas and subsequently dried. Four different types of wood were used: chestnut, cherry, acacia and oak. Large differences were observed between the woods studied with regards to their volatile and polyphenolic profiles. Sensory evaluations confirmed large differences even with short-term contact between the wines and the lees, showing that the method could be of interest for red wine making. In addition, the results demonstrate the potential of using woods other than oak in cooperage. Copyright © 2014 Elsevier Ltd. All rights reserved.

  6. Biomedical applications of yeast- a patent view, part one: yeasts as workhorses for the production of therapeutics and vaccines.

    Science.gov (United States)

    Roohvand, Farzin; Shokri, Mehdi; Abdollahpour-Alitappeh, Meghdad; Ehsani, Parastoo

    2017-08-01

    Yeasts, as Eukaryotes, offer unique features for ease of growth and genetic manipulation possibilities, making it an exceptional microbial host. Areas covered: This review provides general and patent-oriented insights into production of biopharmaceuticals by yeasts. Patents, wherever possible, were correlated to the original or review articles. The review describes applications of major GRAS (generally regarded as safe) yeasts for the production of therapeutic proteins and subunit vaccines; additionally, immunomodulatory properties of yeast cell wall components were reviewed for use of whole yeast cells as a new vaccine platform. The second part of the review will discuss yeast- humanization strategies and innovative applications. Expert opinion: Biomedical applications of yeasts were initiated by utilization of Saccharomyces cerevisiae, for production of leavened (fermented) products, and advanced to serve to produce biopharmaceuticals. Higher biomass production and expression/secretion yields, more similarity of glycosylation patterns to mammals and possibility of host-improvement strategies through application of synthetic biology might enhance selection of Pichia pastoris (instead of S. cerevisiae) as a host for production of biopharmaceutical in future. Immunomodulatory properties of yeast cell wall β-glucans and possibility of intracellular expression of heterologous pathogen/tumor antigens in yeast cells have expanded their application as a new platform, 'Whole Yeast Vaccines'.

  7. Taming wild yeast: potential of conventional and nonconventional yeasts in industrial fermentations.

    Science.gov (United States)

    Steensels, Jan; Verstrepen, Kevin J

    2014-01-01

    Yeasts are the main driving force behind several industrial food fermentation processes, including the production of beer, wine, sake, bread, and chocolate. Historically, these processes developed from uncontrolled, spontaneous fermentation reactions that rely on a complex mixture of microbes present in the environment. Because such spontaneous processes are generally inconsistent and inefficient and often lead to the formation of off-flavors, most of today's industrial production utilizes defined starter cultures, often consisting of a specific domesticated strain of Saccharomyces cerevisiae, S. bayanus, or S. pastorianus. Although this practice greatly improved process consistency, efficiency, and overall quality, it also limited the sensorial complexity of the end product. In this review, we discuss how Saccharomyces yeasts were domesticated to become the main workhorse of food fermentations, and we investigate the potential and selection of nonconventional yeasts that are often found in spontaneous fermentations, such as Brettanomyces, Hanseniaspora, and Pichia spp.

  8. Not your ordinary yeast: non-Saccharomyces yeasts in wine production uncovered.

    Science.gov (United States)

    Jolly, Neil P; Varela, Cristian; Pretorius, Isak S

    2014-03-01

    Saccharomyces cerevisiae and grape juice are 'natural companions' and make a happy wine marriage. However, this relationship can be enriched by allowing 'wild' non-Saccharomyces yeast to participate in a sequential manner in the early phases of grape must fermentation. However, such a triangular relationship is complex and can only be taken to 'the next level' if there are no spoilage yeast present and if the 'wine yeast' - S. cerevisiae - is able to exert its dominance in time to successfully complete the alcoholic fermentation. Winemakers apply various 'matchmaking' strategies (e.g. cellar hygiene, pH, SO2 , temperature and nutrient management) to keep 'spoilers' (e.g. Dekkera bruxellensis) at bay, and allow 'compatible' wild yeast (e.g. Torulaspora delbrueckii, Pichia kluyveri, Lachancea thermotolerans and Candida/Metschnikowia pulcherrima) to harmonize with potent S. cerevisiae wine yeast and bring the best out in wine. Mismatching can lead to a 'two is company, three is a crowd' scenario. More than 40 of the 1500 known yeast species have been isolated from grape must. In this article, we review the specific flavour-active characteristics of those non-Saccharomyces species that might play a positive role in both spontaneous and inoculated wine ferments. We seek to present 'single-species' and 'multi-species' ferments in a new light and a new context, and we raise important questions about the direction of mixed-fermentation research to address market trends regarding so-called 'natural' wines. This review also highlights that, despite the fact that most frontier research and technological developments are often focussed primarily on S. cerevisiae, non-Saccharomyces research can benefit from the techniques and knowledge developed by research on the former. © 2013 Federation of European Microbiological Societies. Published by John Wiley & Sons Ltd. All rights reserved.

  9. Frontiers of yeast metabolic engineering: diversifying beyond ethanol and Saccharomyces.

    Science.gov (United States)

    Liu, Leqian; Redden, Heidi; Alper, Hal S

    2013-12-01

    Microbial systems provide an attractive, renewable route to produce desired organic molecules such as fuels and chemicals. While attention within the field of metabolic engineering has mostly focused on Escherichia coli, yeast is a potent host and growing host for industrial products and has many outstanding, biotechnologically desirable native traits. Thus, there has been a recent shift in focus toward yeast as production hosts to replace E. coli. As such, products have diversified in yeast beyond simply ethanol. Additionally, nonconventional yeasts have been considered to move beyond Saccharomyces cerevisiae. This review highlights recent advances in metabolic engineering of yeasts for producing value-added chemical compounds including alcohols, sugar derivatives, organic acids, fats, terpenes, aromatics, and polyketides. Furthermore, we will also discuss the future direction of metabolic engineering of yeasts. Copyright © 2013 Elsevier Ltd. All rights reserved.

  10. Biosorption of nickel by yeasts in an osmotically unsuitable environment

    Energy Technology Data Exchange (ETDEWEB)

    Breierova, Emilia; Kovarova, Annamaria [SAS, Bratislava (Slovakia). Inst. of Chemistry; Certik, Milan [SUT, Bratislava (Slovakia). Dept. of Biochemical Technology; Gregor, Tomas [Mendel Univ. of Agriculture and Forestry, Brno (Czech Republic)

    2008-11-15

    The tolerance, sorption of nickel(II) ions, and changes in the production and composition of exopolymers of eight yeast strains grown under nickel presence with/without NaCl were studied. Strains of Pichia anomala and Candida maltosa known as the most resistant yeasts against nickel tolerated up to 3 mm Ni{sup 2+}. NaCl addition decreased both the resistance ofthe yeast strains toward nickel ions and the sorption of metal ions into cells. All yeasts absorbed nickel predominantly into exopolymers (glycoproteins) and on the surface of cells. However, while the amount of polysaccharide moieties of exoglycoproteins of most of the resistant yeasts was induced by stress conditions, the ratio polysaccharide/protein in the exopolymers remained unchanged in the sensitive species Cystofilobasidium. The exopolymer composition might play a key role in yeast adaptation to stress conditions caused by heavy metal ions. (orig.)

  11. Ecology and Biodiversity of Yeasts with Potential Value in Biotechnology

    Science.gov (United States)

    Deak, T.

    In the latest edition of the standard treatise of yeasts, in 1998, 700 species were described. Since then, the number of recognized yeast species has doubled, with a steep increase particularly in the number of the basidiomycetous yeasts. Of all these yeast species, only about a dozen is used at industrial scale, and some 70 - 80 species have been shown at laboratory scale to possess potential value in biotechnology; their ratio is, in the best case, 5 - 10 %. If it is accepted, that according to a modest estimate, the known yeast species represent only 5 % of the total number which may inhabit the Earth, then there is ample room to search for new species with novel potential to exploit. Where could these yeasts be discovered?

  12. A new methodology to obtain wine yeast strains overproducing mannoproteins.

    Science.gov (United States)

    Quirós, Manuel; Gonzalez-Ramos, Daniel; Tabera, Laura; Gonzalez, Ramon

    2010-04-30

    Yeast mannoproteins are highly glycosylated proteins that are covalently bound to the beta-1,3-glucan present in the yeast cell wall. Among their outstanding enological properties, yeast mannoproteins contribute to several aspects of wine quality by protecting against protein haze, reducing astringency, retaining aroma compounds and stimulating growth of lactic-acid bacteria. The development of a non-recombinant method to obtain enological yeast strains overproducing mannoproteins would therefore be very useful. Our previous experience on the genetic determinants of the release of these molecules by Saccharomyces cerevisiae has allowed us to propose a new methodology to isolate and characterize wine yeast that overproduce mannoproteins. The described methodology is based on the resistance of the killer 9 toxin produced by Williopsis saturnus, a feature linked to an altered biogenesis of the yeast cell wall. Copyright 2010 Elsevier B.V. All rights reserved.

  13. Yeast buddies helping to unravel the complexity of neurodegenerative disorders.

    Science.gov (United States)

    Fruhmann, Gernot; Seynnaeve, David; Zheng, Ju; Ven, Karen; Molenberghs, Sofie; Wilms, Tobias; Liu, Beidong; Winderickx, Joris; Franssens, Vanessa

    2017-01-01

    Neurodegenerative disorders have a profound effect on the quality of life of patients and their environment. However, the development of adequate therapies requires accurate understanding of the underlying disease pathogenesis. On that account, yeast models can play an important role, as they enable the elucidation of the mechanisms leading to neurodegenerative disorders. Furthermore, by using so-called humanized yeast systems, the findings in yeast can be interpolated to humans. In this review, we will give an overview of the current body of knowledge on the use of yeast models with regard to Huntington's, Parkinson's and Alzheimer's disease. In addition to the results, obtained with the baker's yeast Saccharomyces cerevisiae, we also consider the existing literature on the less common but promising fission yeast Schizosaccharomyces pombe. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

  14. Differentiation of enzymatic activity of yeasts and yeast-like microorganisms isolated from various environments

    Directory of Open Access Journals (Sweden)

    Elżbieta Bogusławska-Wąs

    2014-08-01

    Full Text Available The aim of study was to determinate enzymatic activity of yeast-like organisms - Candida lipolytica, Rhodotorula rubra, Trichosporon beigelii, Zygosaccharomyces sp. - isolated from the Szczecin Lagoon and herring salads. We have shown that lipolytic activity was higher than protcolytic for every strain tested. The lowest activity level was found out for amylolytic hydrolases. The results also demonstrated that yeast-like organisms isolated from the Szczecin Lagoon revealed much higher average enzymatic activity compared to tbe same species isolated from herring salads, excepting C. lipolytica.

  15. Breaking Oil-in-water Emulsions Stabilized By Yeast

    OpenAIRE

    Furtado; Guilherme F.; Picone; Carolina S. F.; Cuellar; Maria C.; Cunha; Rosiane L.

    2016-01-01

    Several biotechnological processes can show an undesirable formation of emulsions making difficult phase separation and product recovery. The breakup of oil-in-water emulsions stabilized by yeast was studied using different physical and chemical methods. These emulsions were composed by deionized water, hexadecane and commercial yeast (Saccharomyces cerevisiae). The stability of the emulsions was evaluated varying the yeast concentration from 7.47 to 22.11% (w/w) and the phases obtained after...

  16. Extracellular protease from the antarctic yeast Candida humicola.

    OpenAIRE

    Ray, M K; Devi, K U; Kumar, G S; Shivaji, S

    1992-01-01

    The psychrotrophic, dimorphic yeast Candida humicola, isolated from Antarctic soil, secretes an acidic protease into the medium. The secretion of this protease by C. humicola was found to be dependent on the composition of the medium. In YPD or yeast nitrogen base medium containing either amino acids or ammonium sulfate as the nitrogen source, the activity of the protease in the medium was low (basal level). However, when yeast nitrogen base medium was depleted of amino acids or ammonium sulf...

  17. Yeast species associated with the spontaneous fermentation of cider

    OpenAIRE

    Suárez, Belén; Pando, Rosa; Fernández, Norman; Querol, A.; Rodríguez, Roberto

    2011-01-01

    This paper reports the influence of cider-making technology (pneumatic and traditional pressing) on the dynamics of wild yeast populations. Yeast colonies isolated from apple juice before and throughout fermentation at a cider cellar of Asturias (Spain), during two consecutive years were studied. The yeast strains were identified by restriction fragment length polymorphism analysis of the 5.8S rRNA gene and the two flanking internal transcribed sequences (ITS). The musts obtained by ...

  18. Probiotic properties of yeasts occurring in fermented food and beverages

    DEFF Research Database (Denmark)

    Jespersen, Lene

    Besides being able to improve the quality and safety of many fermented food and beverages some yeasts offer a number of probiotic traits. Especially a group of yeast referred to as "Saccharomyces boulardii", though taxonomically belonging to Saccharomyces cerevisiae, has been claimed to have...... probiotic properties. Besides, yeasts naturally occurring globally in food and beverages will have traits that might have a positive impact on human health....

  19. Red Yeast Rice Preparations: Are They Suitable Substitutions for Statins?

    Science.gov (United States)

    Dujovne, Carlos A

    2017-10-01

    Red yeast rice, a commercially available food supplement known to reduce serum cholesterol, has been repeatedly advocated as alternative therapy for hypercholesterolemic patients that refuse statins, cannot tolerate statin therapy's side effects, or request a "naturopathic" medicine. Red yeast rice contains a fungus (Monascus purpureus), which was utilized in the original production of lovastatin (MEVACOR, Merck & Co, Whitehouse Station, NJ), the first marketed pharmaceutical statin, and is chemically identical to such product. Their identical properties account for the similarity in therapeutic and side effects of red yeast rice and lovastatin. The red yeast rice ingredient that blocks cholesterol production is monacolin K. Because red yeast rice preparations have large variability in monacolin K content, predicting or understanding dose-related efficacy and side-effect risks of red yeast rice is practically impossible. The lipid-regulating potency of red yeast rice in commercial preparations was found to be extensively different according to the number or concentration of monacolin K they possess. Furthermore, more than one type of monacolin was found in different preparations (or batches) of red yeast rice. Other ingredients found in red yeast rice are also known to be potentially toxic. The US Food and Drug Administration issued warnings to consumers in 2007 and in 2013 against taking red yeast rice products due to the lack of assurance about its efficacy, safety, and lack of standardized preparation methods. This article discusses my clinical trial results with red yeast rice, reviews the literature on its therapeutic and side effects, and discusses why red yeast rice is not an acceptable substitution for statins. Copyright © 2017 Elsevier Inc. All rights reserved.

  20. The complexity and implications of yeast prion domains

    OpenAIRE

    Du, Zhiqiang

    2011-01-01

    Prions are infectious proteins with altered conformations converted from otherwise normal host proteins. While there is only one known mammalian prion protein, PrP, a handful of prion proteins have been identified in the yeast Saccharomyces cerevisiae. Yeast prion proteins usually have a defined region called prion domain (PrD) essential for prion properties, which are typically rich in glutamine (Q) and asparagine (N). Despite sharing several common features, individual yeast PrDs are genera...

  1. Microbial Populations in Naked Neck Chicken Ceca Raised on Pasture Flock Fed with Commercial Yeast Cell Wall Prebiotics via an Illumina MiSeq Platform.

    Directory of Open Access Journals (Sweden)

    Si Hong Park

    Full Text Available Prebiotics are non-digestible carbohydrate dietary supplements that selectively stimulate the growth of one or more beneficial bacteria in the gastrointestinal tract of the host. These bacteria can inhibit colonization of pathogenic bacteria by producing antimicrobial substances such as short chain fatty acids (SCFAs and competing for niches with pathogens within the gut. Pasture flock chickens are generally raised outdoors with fresh grass, sunlight and air, which represents different environmental growth conditions compared to conventionally raised chickens. The purpose of this study was to evaluate the difference in microbial populations from naked neck chicken ceca fed with commercial prebiotics derived from brewer's yeast cell wall via an Illumina MiSeq platform. A total of 147 day-of-hatch naked neck chickens were distributed into 3 groups consisted of 1 C: control (no prebiotic, 2 T1: Biolex® MB40 with 0.2%, and 3 T2: Leiber® ExCel with 0.2%, consistently supplemented prebiotics during the experimental period. At 8 weeks, a total of 15 birds from each group were randomly selected and ceca removed for DNA extraction. The Illumina Miseq platform based on V4 region of 16S rRNA gene was applied for microbiome analysis. Both treatments exhibited limited impact on the microbial populations at the phylum level, with no significant differences in the OTU number of Bacteroidetes among groups and an increase of Proteobacteria OTUs for the T1 (Biolex® MB40 group. In addition there was a significant increase of genus Faecalibacterium OTU, phylum Firmicutes. According to the development of next generation sequencing (NGS, microbiome analysis based on 16S rRNA gene proved to be informative on the prebiotic impact on poultry gut microbiota in pasture-raised naked neck birds.

  2. Adsorption of egg albumin onto methylated yeast biomass

    OpenAIRE

    Seki, Hideshi; Suzuki, Akira; Maruyama, Hideo

    2004-01-01

    A new biosorbent, methylated yeast (MeYE), was prepared for the adsorptive separation of proteins from aqueous solutions. Yeast was methylated in a 0.1 M HCl methyl alcohol solution at room temperature. About 80% of the carboxylic groups of yeast could be methylated within 9 h. The adsorption of egg albumin to MeYE was studied to evaluate the protein adsorption ability of MeYE. At near neutral pH, egg albumin was scarcely adsorbed to unmethylated yeast and the adsorption amount of egg albumin...

  3. Aboveground Deadwood Deposition Supports Development of Soil Yeasts

    Directory of Open Access Journals (Sweden)

    Thorsten Wehde

    2012-12-01

    Full Text Available Unicellular saprobic fungi (yeasts inhabit soils worldwide. Although yeast species typically occupy defined areas on the biome scale, their distribution patterns within a single type of vegetation, such as forests, are more complex. In order to understand factors that shape soil yeast communities, soils collected underneath decaying wood logs and under forest litter were analyzed. We isolated and identified molecularly a total of 25 yeast species, including three new species. Occurrence and distribution of yeasts isolated from these soils provide new insights into ecology and niche specialization of several soil-borne species. Although abundance of typical soil yeast species varied among experimental plots, the analysis of species abundance and community composition revealed a strong influence of wood log deposition and leakage of organic carbon. Unlike soils underneath logs, yeast communities in adjacent areas harbored a considerable number of transient (phylloplane-related yeasts reaching 30% of the total yeast quantity. We showed that distinguishing autochthonous community members and species transient in soils is essential to estimate appropriate effects of environmental factors on soil fungi. Furthermore, a better understanding of species niches is crucial for analyses of culture-independent data, and may hint to the discovery of unifying patterns of microbial species distribution.

  4. In Situ Assays of Chemotropism During Yeast Mating.

    Science.gov (United States)

    Stone, David E; Arkowitz, Robert A

    2016-01-01

    Virtually all eukaryotic cells can grow in a polarized fashion in response to external signals. Cells can respond to gradients of chemoattractants or chemorepellents by directional growth, a process referred to as chemotropism. The budding yeast Saccharomyces cerevisiae undergoes chemotropic growth during mating, in which two haploid cells of opposite mating type grow towards one another. Mating pheromone gradients are essential for efficient mating in yeast and different yeast mutants are defective in chemotropism. Two methods of assessing the ability of yeast strains to respond to pheromone gradients are presented here.

  5. Improved vanillin production in baker's yeast through in silico design

    National Research Council Canada - National Science Library

    Brochado, Ana Rita; Matos, Claudia; Møller, Birger L; Hansen, Jørgen; Mortensen, Uffe H; Patil, Kiran Raosaheb

    2010-01-01

    .... Currently vanillin is mostly produced via chemical synthesis. A de novo synthetic pathway for heterologous vanillin production from glucose has recently been implemented in baker's yeast, Saccharamyces cerevisiae...

  6. Variation in yeast mitochondrial activity associated with asci.

    Science.gov (United States)

    Swart, Chantel W; van Wyk, Pieter W J; Pohl, Carolina H; Kock, Johan L F

    2008-07-01

    An increase in mitochondrial membrane potential (DeltaPsim) and mitochondrially produced 3-hydroxy (3-OH) oxylipins was experienced in asci of the nonfermentative yeasts Galactomyces reessii and Lipomyces starkeyi and the fermentative yeasts Pichia farinosa and Schizosaccharomyces octosporus. Strikingly, asci of Zygosaccharomyces bailii showed no increase in mitochondrial activity (DeltaPsim and oxylipin production). As expected, oxygen deprivation only inhibited ascus formation in those yeasts with increased ascus mitochondrial activity. We conclude that ascus formation in yeasts is not always dependent on mitochondrial activity. In this case, fermentation may provide enough energy for ascus formation in Z. bailii.

  7. Effect of fungicides on epiphytic yeasts associated with strawberry

    Science.gov (United States)

    Debode, Jane; Van Hemelrijck, Wendy; Creemers, Piet; Maes, Martine

    2013-01-01

    We studied the effect of two commonly used fungicides on the epiphytic yeast community of strawberry. Greenhouse and field experiments were conducted applying Switch (cyprodinil plus fludioxonil) or Signum (boscalid plus pyraclostrobin) to strawberry plants. Yeasts on leaves and fruits were assessed on treated and untreated plants at several time points via plating and denaturing gradient gel electrophoresis (DGGE) analysis. The yeast counts on plates of the treated plants were similar to the control plants. Unripe fruits had 10 times larger yeast concentrations than ripe fruits or leaves. Some dominant yeast types were isolated and in vitro tests showed that they were at least 10 times less sensitive to Switch and Signum as compared with two important fungal strawberry pathogens Botrytis cinerea and Colletotrichum acutatum, which are the targets for the fungicide control. DGGE analysis showed that the applied fungicides had no effect on the composition of the yeast communities, while the growing system, strawberry tissue, and sampling time did affect the yeast communities. The yeast species most commonly identified were Cryptococcus, Rhodotorula, and Sporobolomyces. These results point toward the potential applicability of natural occurring yeast antagonists into an integrated disease control strategy for strawberry diseases.

  8. Effect of dietary yeast autolysate on performance, slaughter, and ...

    African Journals Online (AJOL)

    TOSHIBA

    2017-05-22

    Saccharomyces cerevisiae) on performance ... Keywords: Carcass attributes, carcass percentages, growth, sex ... yeast, as natural growth and performance enhancers as alternatives to antibiotics in poultry diets (Bonos et al.,.

  9. The yeast osmostress response is carbon source dependent

    DEFF Research Database (Denmark)

    Babazadeh, Roja; Lahtvee, Petri-Jaan; Adiels, Caroline B.

    2017-01-01

    to now, essentially all osmostress studies in yeast have been performed with glucose as carbon and energy source, which is metabolised by glycolysis with glycerol as a by-product. Here we investigated the response of yeast to osmotic stress when yeast is respiring ethanol as carbon and energy source....... Remarkably, yeast cells do not accumulate glycerol under these conditions and it appears that trehalose may partly take over the role as compatible solute. The HOG pathway is activated in very much the same way as during growth on glucose and is also required for osmotic adaptation. Slower volume recovery...

  10. Applications of yeast surface display for protein engineering

    Science.gov (United States)

    Cherf, Gerald M.; Cochran, Jennifer R.

    2015-01-01

    The method of displaying recombinant proteins on the surface of Saccharomyces cerevisiae via genetic fusion to an abundant cell wall protein, a technology known as yeast surface display, or simply, yeast display, has become a valuable protein engineering tool for a broad spectrum of biotechnology and biomedical applications. This review focuses on the use of yeast display for engineering protein affinity, stability, and enzymatic activity. Strategies and examples for each protein engineering goal are discussed. Additional applications of yeast display are also briefly presented, including protein epitope mapping, identification of protein-protein interactions, and uses of displayed proteins in industry and medicine. PMID:26060074

  11. Influência da alimentação de Anagasta kuehniella Zeller(Lepidoptera: Pyralidae no desenvolvimento de Ceraeochrysa cubana Hagen (Neuroptera: Chrysopidae

    Directory of Open Access Journals (Sweden)

    Gilmar Nunes

    2017-04-01

    Abstract. Aimed to evaluate the biological development of Ceraeochrysa cubana Hagen immature stages fed on eggs of the mothsubmitted to different food substrates with ingredients on different concentrations (%: Corn flour (50% + Wheat flour (50% + Brewer’s yeast (3%; Transgenic corn flour (50% + Wheat flour (50% + Brewer’s yeast (3%; Breadcrumbs (97% + Brewer’s yeast (3%; Breadcrumbs (48.5% + Wheat flour (48.5% + Brewer’s yeast (3%; Rice flour (97% + Brewer’s yeast (3%; Rice flour (48.5% + Wheat flour (48.5 % + Brewer’s yeast (3%; Oatmeal (97% + Brewer’s yeast (3%; Oatmeal (48.5% + Wheat flour (48.5% + Brewer’s yeast (3%. We evaluated the period of each larval stage, complete larval period, pre pupal+pupal period, and larva to adulthood period, larval and pupal feasibility. Diets with oatmeal provided for moth promote greater time for the predator reach adulthood, with rice flour low sex ratio and with breadcrumbs low pupal feasibility. Diets formulated with corn flours + brewer’s yeast are most recommended for Ephestia kuehniella Zeller, aiming C. cubana mass rearing.

  12. Cytology, Cell Walls and septa: A Summary of Yeast Cell Biology from a Phylogenetic Perspective

    NARCIS (Netherlands)

    Klei, I.; Veenhuis, M.; Brul, S.; Klis, F.M.; de Groot, P.W.J.; Müller, W.H.; van Driel, K.G.A.; Boekhout, T.; Kurtzman, C. P.; Fell, J. W.; Boekhout, T.

    2011-01-01

    his chapter aims to present an overview of yeast cell biology, biochemical structure and composition of cell walls in various yeast species, septal pore ultrastructure, and other subcellular characteristics, and a phylogenetic framework to these observations. Yeast cells have ultrastructural

  13. Yeast Interacting Proteins Database: YGR013W, YKL012W [Yeast Interacting Proteins Database

    Lifescience Database Archive (English)

    Full Text Available st specific, no metazoan counterpart Rows with this bait as bait (1) Rows with this bait as prey (0) YKL012W...U71 Bait description Component of U1 snRNP required for mRNA splicing via spliceosome; yeast specific, no metazoan counter

  14. Genetically modified yeast species, and fermentation processes using genetically modified yeast

    Energy Technology Data Exchange (ETDEWEB)

    Rajgarhia, Vineet; Koivuranta, Kari; Penttila, Merja; Ilmen, Marja; Suominen, Pirkko; Aristidou, Aristos; Miller, Christopher Kenneth; Olson, Stacey; Ruohonen, Laura

    2016-08-09

    Yeast cells are transformed with an exogenous xylose isomerase gene. Additional genetic modifications enhance the ability of the transformed cells to ferment xylose to ethanol or other desired fermentation products. Those modifications include deletion of non-specific or specific aldose reductase gene(s), deletion of xylitol dehydrogenase gene(s) and/or overexpression of xylulokinase.

  15. Dynamic changes in brewing yeast cells in culture revealed by statistical analyses of yeast morphological data.

    Science.gov (United States)

    Ohnuki, Shinsuke; Enomoto, Kenichi; Yoshimoto, Hiroyuki; Ohya, Yoshikazu

    2014-03-01

    The vitality of brewing yeasts has been used to monitor their physiological state during fermentation. To investigate the fermentation process, we used the image processing software, CalMorph, which generates morphological data on yeast mother cells and bud shape, nuclear shape and location, and actin distribution. We found that 248 parameters changed significantly during fermentation. Successive use of principal component analysis (PCA) revealed several important features of yeast, providing insight into the dynamic changes in the yeast population. First, PCA indicated that much of the observed variability in the experiment was summarized in just two components: a change with a peak and a change over time. Second, PCA indicated the independent and important morphological features responsible for dynamic changes: budding ratio, nucleus position, neck position, and actin organization. Thus, the large amount of data provided by imaging analysis can be used to monitor the fermentation processes involved in beer and bioethanol production. Copyright © 2013 The Society for Biotechnology, Japan. Published by Elsevier B.V. All rights reserved.

  16. Utilization of spent brewer’s yeast Saccharomyces cerevisiae for the production of yeast enzymatic hydrolysate

    Directory of Open Access Journals (Sweden)

    M Bayarjargal

    2014-09-01

    Full Text Available Spent brewer’s yeast (Saccharomyces cerevisiae is a rich source of protein, vitamins and widely used as a raw material for production of food supplements. The autolysis and enzymatic treatment of spent brewer’s yeast using Pancreatin (2.5% and Flavourzyme (2.5% were performed at 45 °C and 50 °C, respectively. The autolysis and hydrolysis processes were evaluated by determining a soluble solids, soluble protein concentration and α-amino nitrogen content in a reaction mixture. The yield of pancreatic digest and α-amino nitrogen content was high in comparison with autolysis and Flavourzyme treatment. The total solids recovery in dry Yeast hydrolysate was about 50%, a protein and α-amino nitrogen content was 55.9 and 4.8%, respectively. These results show the possibility of utilizing the spent brewer’s yeast as hydrolysate using hydrolytic enzymes and use it as a food supplement after biological experiments.DOI: http://dx.doi.org/10.5564/mjc.v12i0.179 Mongolian Journal of Chemistry Vol.12 2011: 88-91

  17. Genetically modified yeast species, and fermentation processes using genetically modified yeast

    Science.gov (United States)

    Rajgarhia, Vineet; Koivuranta, Kari; Penttila, Merja; Ilmen, Marja; Suominen, Pirkko; Aristidou, Aristos; Miller, Christopher Kenneth; Olson, Stacey; Ruohonen, Laura

    2013-05-14

    Yeast cells are transformed with an exogenous xylose isomerase gene. Additional genetic modifications enhance the ability of the transformed cells to ferment xylose to ethanol or other desired fermentation products. Those modifications include deletion of non-specific or specific aldose reductase gene(s), deletion of xylitol dehydrogenase gene(s) and/or overexpression of xylulokinase.

  18. Genetically modified yeast species, and fermentation processes using genetically modified yeast

    Energy Technology Data Exchange (ETDEWEB)

    Rajgarhia, Vineet; Koivuranta, Kari; Penttila, Merja; Ilmen, Marja; Suominen, Pirkko; Aristidou, Aristos; Miller, Christopher Kenneth; Olson, Stacey; Ruohonen, Laura

    2017-09-12

    Yeast cells are transformed with an exogenous xylose isomerase gene. Additional genetic modifications enhance the ability of the transformed cells to ferment xylose to ethanol or other desired fermentation products. Those modifications include deletion of non-specific or specific aldose reductase gene(s), deletion of xylitol dehydrogenase gene(s) and/or overexpression of xylulokinase.

  19. How does yeast respond to pressure?

    Directory of Open Access Journals (Sweden)

    P.M.B. Fernandes

    2005-08-01

    Full Text Available The brewing and baking yeast Saccharomyces cerevisiae has been used as a model for stress response studies of eukaryotic cells. In this review we focus on the effect of high hydrostatic pressure (HHP on S. cerevisiae. HHP exerts a broad effect on yeast cells characteristic of common stresses, mainly associated with protein alteration and lipid bilayer phase transition. Like most stresses, pressure induces cell cycle arrest. Below 50 MPa (500 atm yeast cell morphology is unaffected whereas above 220 MPa wild-type cells are killed. S. cerevisiae cells can acquire barotolerance if they are pretreated with a sublethal stress due to temperature, ethanol, hydrogen peroxide, or pressure. Nevertheless, pressure only leads to protection against severe stress if, after pressure pretreatment, the cells are also re-incubated at room pressure. We attribute this effect to the inhibition of the protein synthesis apparatus under HHP. The global genome expression analysis of S. cerevisiae cells submitted to HHP revealed a stress response profile. The majority of the up-regulated genes are involved in stress defense and carbohydrate metabolism while most repressed genes belong to the cell cycle progression and protein synthesis categories. However, the signaling pathway involved in the pressure response is still to be elucidated. Nitric oxide, a signaling molecule involved in the regulation of a large number of cellular functions, confers baroprotection. Furthermore, S. cerevisiae cells in the early exponential phase submitted to 50-MPa pressure show induction of the expression level of the nitric oxide synthase inducible isoform. As pressure becomes an important biotechnological tool, studies concerning this kind of stress in microorganisms are imperative.

  20. Crystal structure of yeast Sco1

    Energy Technology Data Exchange (ETDEWEB)

    Abajian, Carnie; Rosenzweig, Amy C. (NWU)

    2010-03-05

    The Sco family of proteins are involved in the assembly of the dinuclear CuA site in cytochrome c oxidase (COX), the terminal enzyme in aerobic respiration. These proteins, which are found in both eukaryotes and prokaryotes, are characterized by a conserved CXXXC sequence motif that binds copper ions and that has also been proposed to perform a thiol:disulfide oxidoreductase function. The crystal structures of Saccharomyces cerevisiae apo Sco1 (apo-ySco1) and Sco1 in the presence of copper ions (Cu-ySco1) were determined to 1.8- and 2.3-{angstrom} resolutions, respectively. Yeast Sco1 exhibits a thioredoxin-like fold, similar to that observed for human Sco1 and a homolog from Bacillus subtilis. The Cu-ySco1 structure, obtained by soaking apo-ySco1 crystals in copper ions, reveals an unexpected copper-binding site involving Cys181 and Cys216, cysteine residues present in ySco1 but not in other homologs. The conserved CXXXC cysteines, Cys148 and Cys152, can undergo redox chemistry in the crystal. An essential histidine residue, His239, is located on a highly flexible loop, denoted the Sco loop, and can adopt positions proximal to both pairs of cysteines. Interactions between ySco1 and its partner proteins yeast Cox17 and yeast COX2 are likely to occur via complementary electrostatic surfaces. This high-resolution model of a eukaryotic Sco protein provides new insight into Sco copper binding and function.

  1. Population FBA predicts metabolic phenotypes in yeast.

    Directory of Open Access Journals (Sweden)

    Piyush Labhsetwar

    2017-09-01

    Full Text Available Using protein counts sampled from single cell proteomics distributions to constrain fluxes through a genome-scale model of metabolism, Population flux balance analysis (Population FBA successfully described metabolic heterogeneity in a population of independent Escherichia coli cells growing in a defined medium. We extend the methodology to account for correlations in protein expression arising from the co-regulation of genes and apply it to study the growth of independent Saccharomyces cerevisiae cells in two different growth media. We find the partitioning of flux between fermentation and respiration predicted by our model agrees with recent 13C fluxomics experiments, and that our model largely recovers the Crabtree effect (the experimentally known bias among certain yeast species toward fermentation with the production of ethanol even in the presence of oxygen, while FBA without proteomics constraints predicts respirative metabolism almost exclusively. The comparisons to the 13C study showed improvement upon inclusion of the correlations and motivated a technique to systematically identify inconsistent kinetic parameters in the literature. The minor secretion fluxes for glycerol and acetate are underestimated by our method, which indicate a need for further refinements to the metabolic model. For yeast cells grown in synthetic defined (SD medium, the calculated broad distribution of growth rates matches experimental observations from single cell studies, and we characterize several metabolic phenotypes within our modeled populations that make use of diverse pathways. Fast growing yeast cells are predicted to perform significant amount of respiration, use serine-glycine cycle and produce ethanol in mitochondria as opposed to slow growing cells. We use a genetic algorithm to determine the proteomics constraints necessary to reproduce the growth rate distributions seen experimentally. We find that a core set of 51 constraints are essential but

  2. Ribosylurea accumulates in yeast urc4 mutants.

    Science.gov (United States)

    Björnberg, O; Vodnala, M; Domkin, V; Hofer, A; Rasmussen, A; Andersen, G; Piskur, J

    2010-06-01

    Yeast Saccharomyces (Lachancea) kluyveri urc4 mutants, unable to grow on uracil, biotransformed (14)C(2)-uracil into two labeled compounds, as detected by high performance liquid chromatography (HPLC). These two compounds could also be obtained following organic synthesis of ribosylurea. This finding demonstrates that in the URC pyrimidine degradation pathway, the opening of the uracil ring takes place when uracil is attached to the ribose moiety. Ribosylurea has not been reported in the cell metabolism before and the two observed compounds likely represent an equilibrium mixture of the pyranosyl and furanosyl forms.

  3. Structural Studies of the Yeast Mitochondrial Degradosome

    DEFF Research Database (Denmark)

    Feddersen, Ane; Jonstrup, Anette Thyssen; Brodersen, Ditlev Egeskov

    and nuclear exosome complexes, which consist of 10-12 different nuclease subunits, the mitochondrial degradosome is composed of only two large subunits - an RNase (Dss1p) and a helicase (Suv3p), belonging the Ski2 class of DExH box RNA helicases. Both subunits are encoded on the yeast nuclear genome...... and imported to the mitochondrial matrix posttranslationally. In an effort to understand the complex mechanisms underlying control of RNA turnover and surveillance in eukaryotic organisms, we are studying the structure of the mitochondrial degradosome as a model system for the more complex exosomes. Dss1p...

  4. Levaduras inhibidoras de Penicillium Inhibitory Penicillium yeasts

    Directory of Open Access Journals (Sweden)

    M.R. Benítez Ahrendts

    2004-12-01

    Full Text Available El objetivo de este trabajo fue determinar la acción inhibitoria in vitro e in vivo de algunas cepas de levaduras de la zona citrícola jujeña sobre el crecimiento de los mohos patógenos post-cosecha y seleccionarlas para elaborar un producto de biocontrol. Se aislaron de frutos cítricos cepas de los mohos patógenos post-cosecha Penicillium digitatum, P. italicum,P. ulaiense, Phyllosticta sp. y Galactomyces geotrichum, así como de levaduras saprófítas de los géneros Brettanomyces, Candida, Cryptococcus, Kloeckera, Pichia y Rhodotorula. También se obtuvieron algunas levaduras de otras fuentes. Se identificaron las levaduras por las características macro y micromorfológicas y las pruebas fisiológicas. La actividad in vitro e in vivo de las diferentes cepas fue diferente según se enfrentaran a P. digitatum o P. ulaiense. Candida cantarellii y una cepa de Pichia subpelliculosa produjeron una reducción significativa del área de las lesiones provocadas por estas especies de Penicillium, y podrían ser empleadas en la formulación de un producto para biocontrol.The objective of this work was to establish the in vitro and in vivo inhibition of post-harvest pathogenic moulds by yeasts in order to make a biocontrol product. Post-harvest pathogenic moulds Penicillium digitatumP. italicum, P. ulaiense, Phyllosticta sp., Galactomyces geotrichum and yeasts belonging to genera Brettanomyces, Candida, Cryptococcus, Kloeckera,Pichia, Rhodotorula were isolated from citrus fruits. Some yeasts strains were also isolated from other sources. The yeasts were identified by their macro and micro-morphology and physiological tests. The in vitro and in vivo activities against P. digitatum or P. ulaiense were different. Candida cantarellii and one strain of Pichia subpelliculosa produced a significant reduction of the lesion area caused by the pathogenic moulds P. digitatum and P. ulaiense, and could be used in a biocontrol product formulation.

  5. Cyanohydrin reactions enhance glycolytic oscillations in yeast

    DEFF Research Database (Denmark)

    Hald, Bjørn Olav; Nielsen, Astrid Gram; Tortzen, Christian

    2015-01-01

    Synchronous metabolic oscillations can be induced in yeast by addition of glucose and removal of extracellular acetaldehyde (ACAx). Compared to other means of ACAx removal, cyanide robustly induces oscillations, indicating additional cyanide reactions besides ACA to lactonitrile conversion. Here...... for ~66% of total cyanide removal. Simulations of our updated computational model show that intracellular cyanide reactions increase the amplitude of oscillations and that cyanide addition lowers [ACA] instantaneously. We conclude that cyanide provides the following means of inducing global oscillations......: a) by reducing [ACAx] relative to oscillation amplitude, b) by targeting multiple intracellular carbonyl compounds during fermentation, and c) by acting as a phase resetting stimulus....

  6. Laser effects on yeast cell suspensions

    Science.gov (United States)

    Grigorovici, A.; Despa, Sanda I.; Paunescu, Teodor G.

    1995-03-01

    The aim of this paper is to determine the effects produced by coherent electromagnetic radiation in the ultraviolet and visible range on the growth of a Saccharomyces cerevisiae cell suspension. There were made several experiments in which we used different irradiation parameters (power, irradiation time, wavelength) for pointing out those that produce the stimulation or inhibition of the cellular culture growth. Beyond the modifications that appeared in the culture evolution we investigated other physical and chemical changes induced by the laser light on yeast cell suspensions.

  7. The Use of HIS6 Gene as a Selectable Marker for Yeast Vector

    OpenAIRE

    IMADEARTIKA,

    2009-01-01

    The yeast Saccharomyces cerevisiae HIS6 gene has been shown to be functional as a selectable marker for selecting and maintaining a yeast vector in yeast S. cerevisiae host cells. The yeast HIS6 gene encodes an enzyme involved in the yeast histidine biosynthesis. The yeast HIS6 gene was cloned into a yeast expression vector. The resultant recombinant plasmid was introduced into yeast host cells defective in endogenous HIS6 gene. The functionality of the HIS6 gene as a selectable marker was te...

  8. The Use of HIS6 Gene as a Selectable Marker for Yeast Vector

    Directory of Open Access Journals (Sweden)

    IMADEARTIKA

    2009-03-01

    Full Text Available The yeast Saccharomyces cerevisiae HIS6 gene has been shown to be functional as a selectable marker for selecting and maintaining a yeast vector in yeast S. cerevisiae host cells. The yeast HIS6 gene encodes an enzyme involved in the yeast histidine biosynthesis. The yeast HIS6 gene was cloned into a yeast expression vector. The resultant recombinant plasmid was introduced into yeast host cells defective in endogenous HIS6 gene. The functionality of the HIS6 gene as a selectable marker was tested by growing transformed cells on selective minimum medium lacking histidine supplementation.

  9. Psychrophilic yeasts and their biotechnological applications - A review

    African Journals Online (AJOL)

    SAM

    2014-05-28

    May 28, 2014 ... The presence of organic carbon and nitrogen sources in waters, originated from melting glacier ice, have been demonstrated and the occurrence of yeast strains degrading a variety of organic compounds including polysaccharides, esters, lipids and pectin's have been observed in the yeasts isolated from.

  10. RAPYD--rapid annotation platform for yeast data.

    Science.gov (United States)

    Schneider, Jessica; Blom, Jochen; Jaenicke, Sebastian; Linke, Burkhard; Brinkrolf, Karina; Neuweger, Heiko; Tauch, Andreas; Goesmann, Alexander

    2011-08-20

    Lower eukaryotes of the kingdom Fungi include a variety of biotechnologically important yeast species that are in the focus of genome research for more than a decade. Due to the rapid progress in ultra-fast sequencing technologies, the amount of available yeast genome data increases steadily. Thus, an efficient bioinformatics platform is required that covers genome assembly, eukaryotic gene prediction, genome annotation, comparative yeast genomics, and metabolic pathway reconstruction. Here, we present a bioinformatics platform for yeast genomics named RAPYD addressing the key requirements of extensive yeast sequence data analysis. The first step is a comprehensive regional and functional annotation of a yeast genome. A region prediction pipeline was implemented to obtain reliable and high-quality predictions of coding sequences and further genome features. Functions of coding sequences are automatically determined using a configurable prediction pipeline. Based on the resulting functional annotations, a metabolic pathway reconstruction module can be utilized to rapidly generate an overview of organism-specific features and metabolic blueprints. In a final analysis step shared and divergent features of closely related yeast strains can be explored using the comparative genomics module. An in-depth application example of the yeast Meyerozyma guilliermondii illustrates the functionality of RAPYD. A user-friendly web interface is available at https://rapyd.cebitec.uni-bielefeld.de. Copyright © 2010 Elsevier B.V. All rights reserved.

  11. Interactions between yeasts, fungicides and apple fruit russeting

    NARCIS (Netherlands)

    Gildemacher, P.R.; Heijne, B.; Silvestri, M.; Houbraken, J.; Hoekstra, E.; Theelen, B.; Boekhout, T.

    2006-01-01

    The effect of inoculations with yeasts occurring on apple surfaces and fungicide treatments on the russeting of Elstar apples was studied. Captan, dithianon and a water treatment were implemented to study the interaction between the fungicides, the inoculated yeast species and Aureobasidium

  12. Metabolic engineering of yeast for fermentative production of flavonoids

    DEFF Research Database (Denmark)

    Rodriguez Prado, Edith Angelica; Strucko, Tomas; Stahlhut, Steen Gustav

    2017-01-01

    Yeast Saccharomyces cerevisiae was engineered for de novo production of six different flavonoids (naringenin, liquiritigenin, kaempferol, resokaempferol, quercetin, and fisetin) directly from glucose, without supplementation of expensive intermediates. This required reconstruction of long...... demonstrates the potential of flavonoid-producing yeast cell factories....

  13. Bipolar budding in yeasts - an electron microscope study

    NARCIS (Netherlands)

    Kreger-van Rij, N.J.W.; Veenhuis, M.

    1971-01-01

    Bud formation in yeasts with bipolar budding was studied by electron microscopy of thin sections. Budding in yeasts of the species Saccharomycodes ludwigii, Hanseniaspora valbyensis and Wickerhamia fluorescens resulted in concentric rings of scar ridges on the wall of the mother cell. The wall

  14. Phenotypic characters of yeasts isolated from kpete-kpete, a ...

    African Journals Online (AJOL)

    USER

    2015-07-08

    Jul 8, 2015 ... Based on their phenotypic characters and their assimilation profiles, 49 yeasts were isolated and found to belong to five ... marriage, birth, the handing over of a dowry, etc.) and constitute a source of ..... Table 3. Assimilation profiles of yeasts isolated from traditional starter kpete-kpete. Parameter a* b c d. E.

  15. Yeast contamination potential in a carbonated soft drink industry ...

    African Journals Online (AJOL)

    Components of the filling valve in a gravity filling machine namely, tulip rubber, spreader rubber and vent tube were analyzed for yeasts using the membrane filtration method. After 5 days incubation, it was found that the tulip rubber had the highest yeast count of 9 cfu/20mls while the vent tube had the least count of 5 ...

  16. A vaccine grade of yeast Saccharomyces cerevisiae expressing mammalian myostatin

    Directory of Open Access Journals (Sweden)

    Zhang Tingting

    2012-12-01

    Full Text Available Abstract Background Yeast Saccharomyces cerevisiae is a widely-used system for protein expression. We previously showed that heat-killed whole recombinant yeast vaccine expressing mammalian myostatin can modulate myostatin function in mice, resulting in increase of body weight and muscle composition in these animals. Foreign DNA introduced into yeast cells can be lost soon unless cells are continuously cultured in selection media, which usually contain antibiotics. For cost and safety concerns, it is essential to optimize conditions to produce quality food and pharmaceutical products. Results We developed a simple but effective method to engineer a yeast strain stably expressing mammalian myostatin. This method utilized high-copy-number integration of myostatin gene into the ribosomal DNA of Saccharomyces cerevisiae. In the final step, antibiotic selection marker was removed using the Cre-LoxP system to minimize any possible side-effects for animals. The resulting yeast strain can be maintained in rich culture media and stably express mammalian myostatin for two years. Oral administration of the recombinant yeast was able to induce immune response to myostatin and modulated the body weight of mice. Conclusions Establishment of such yeast strain is a step further toward transformation of yeast cells into edible vaccine to improve meat production in farm animals and treat human muscle-wasting diseases in the future.

  17. Investigating the proteins released by yeasts in synthetic wine fermentations.

    Science.gov (United States)

    Mostert, Talitha T; Divol, Benoit

    2014-02-03

    Proteins from various biological sources previously identified in wine play important roles in the functioning and survival of their producers and may exhibit oenological properties. Yeasts contribute significantly to the protein pool during and after alcoholic fermentation. While the extracellular proteins of Saccharomyces cerevisiae, the main wine yeast species, have been characterised, those of non-Saccharomyces yeasts remain restricted to a few enzymes. A more comprehensive insight into all proteins released during fermentation could improve our understanding of how yeasts survive and interact in mixed culture fermentations. This study aimed to characterise the exo-proteome of Saccharomyces and selected non-Saccharomyces yeasts in pure and mixed cultures in a wine-like medium. While S. cerevisiae completed the fermentation rapidly, Metschnikowia pulcherrima hardly fermented and Lachancea thermotolerans fermented slowly but steadily. In sequential fermentations, the kinetics resembled those of the non-Saccharomyces yeasts for a period before switching to that of S. cerevisiae. Identification of the proteins present in wine at the end of fermentation using mass fingerprinting revealed the large diversity of proteins secreted and the influence of yeast interactions therein. The fermentation kinetics observed could partially be explained by the extent of the contribution of the different yeast to the protein content. Copyright © 2013 Elsevier B.V. All rights reserved.

  18. Antioxidant and Anticancer activities of yeast grown on commercial ...

    African Journals Online (AJOL)

    There is also considerable evidence which indicates lower risk of Cancer in yeast extracts and the used commercial media. The present study was conducted to determine antioxidant activity of yeast extracts grown on four different commercial media using DPPH, total phenolic content, total antioxidant activity and TBARS ...

  19. Identification of Yeasts Present in Sour Fermented Foods and Fodder

    NARCIS (Netherlands)

    Middelhoven, W.J.

    2002-01-01

    This paper deals with rapid methods for identification of 50 yeast species frequently isolated from foods and fodders that underwent a lactic acid fermentation. However, many yeast species present in olive brine, alpechin, and other olive products were not treated. The methods required for

  20. The making of biodiversity across the yeast subphyllum

    Science.gov (United States)

    Goals for this research project are to determine how the functional diversity of the yeast subphylum is encoded, and to reconstruct the history of yeasts to elucidate the tempo and mode of functional diversification. The impact of this work will be to integrate discoveries within broadly disseminate...

  1. Characterisation of palm wine yeast isolates for industrial utilisation ...

    African Journals Online (AJOL)

    Characterisation of palm wine yeast isolates for industrial utilisation. IN Nwachukwu, VI Ibekwe, RN Nwabueze, BN Anyanwu. Abstract. Investigations were carried out on yeasts isolated from palm wines obtained from South Eastern Nigeria. The isolates were characterised for certain attributes necessary for ethanol ...

  2. Analysis of the RNA Content of the Yeast "Saccharomyces Cerevisiae"

    Science.gov (United States)

    Deutch, Charles E.; Marshall, Pamela A.

    2008-01-01

    In this article, the authors describe an interconnected set of relatively simple laboratory experiments in which students determine the RNA content of yeast cells and use agarose gel electrophoresis to separate and analyze the major species of cellular RNA. This set of experiments focuses on RNAs from the yeast "Saccharomyces cerevisiae", a…

  3. Identification of GPD1 gene from yeast via fluorescence differential ...

    African Journals Online (AJOL)

    The main task of this work was to identify abiotic stress-induced gene(s) from yeast (Saccharomyces cerevisiae) and introduce it to a prokaryotic system to detect its effect on conferring tolerance to salt stress. Six isolates of yeast (S. cerevisiae) were evaluated under salt and osmotic stresses at concentrations of 2 M NaCl ...

  4. Biotechnology of non-Saccharomyces yeasts--the ascomycetes.

    Science.gov (United States)

    Johnson, Eric A

    2013-01-01

    Saccharomyces cerevisiae and several other yeast species are among the most important groups of biotechnological organisms. S. cerevisiae and closely related ascomycetous yeasts are the major producer of biotechnology products worldwide, exceeding other groups of industrial microorganisms in productivity and economic revenues. Traditional industrial attributes of the S. cerevisiae group include their primary roles in food fermentations such as beers, cider, wines, sake, distilled spirits, bakery products, cheese, sausages, and other fermented foods. Other long-standing industrial processes involving S. cerevisae yeasts are production of fuel ethanol, single-cell protein (SCP), feeds and fodder, industrial enzymes, and small molecular weight metabolites. More recently, non-Saccharomyces yeasts (non-conventional yeasts) have been utilized as industrial organisms for a variety of biotechnological roles. Non-Saccharomyces yeasts are increasingly being used as hosts for expression of proteins, biocatalysts and multi-enzyme pathways for the synthesis of fine chemicals and small molecular weight compounds of medicinal and nutritional importance. Non-Saccharomyces yeasts also have important roles in agriculture as agents of biocontrol, bioremediation, and as indicators of environmental quality. Several of these products and processes have reached commercial utility, while others are in advanced development. The objective of this mini-review is to describe processes currently used by industry and those in developmental stages and close to commercialization primarily from non-Saccharomyces yeasts with an emphasis on new opportunities. The utility of S. cerevisiae in heterologous production of selected products is also described.

  5. Influence of catalyst (Yeast) on the Biomethanization of Selected ...

    African Journals Online (AJOL)

    Yeast catalyzed the rate of biomethanization of waste materials and rate at which it alter the reaction rate has been determined. It was observed that addition of yeast improved the quality and quantity of biogas generated and also fastened the acid and methane forming stages during biomethanization. The volumes of ...

  6. Screening of indigenous Yeast strains of fermented foods of Western ...

    African Journals Online (AJOL)

    s$s informatic

    2012-06-28

    Jun 28, 2012 ... probiotic attributes. MATERIALS AND METHODS. Isolation of yeast. Indigenous yeast were enumerated and isolated from traditional fermented food viz., Bhaturu (uncooked) of Western Himalayas by standard serial dilution technique on potato dextrose agar (peeled potato 250 g, dextrose 20 g, agar 20 g, ...

  7. Effect of salt hyperosmotic stress on yeast cell viability

    Directory of Open Access Journals (Sweden)

    Logothetis Stelios

    2007-01-01

    Full Text Available During fermentation for ethanol production, yeasts are subjected to different kinds of physico-chemical stresses such as: initially high sugar concentration and low temperature; and later, increased ethanol concentrations. Such conditions trigger a series of biological responses in an effort to maintain cell cycle progress and yeast cell viability. Regarding osmostress, many studies have been focused on transcriptional activation and gene expression in laboratory strains of Saccharomyces cerevisiae. The overall aim of this present work was to further our understanding of wine yeast performance during fermentations under osmotic stress conditions. Specifically, the research work focused on the evaluation of NaCl-induced stress responses of an industrial wine yeast strain S. cerevisiae (VIN 13, particularly with regard to yeast cell growth and viability. The hypothesis was that osmostress conditions energized specific genes to enable yeast cells to survive under stressful conditions. Experiments were designed by pretreating cells with different sodium chloride concentrations (NaCl: 4%, 6% and 10% w/v growing in defined media containing D-glucose and evaluating the impact of this on yeast growth and viability. Subsequent fermentation cycles took place with increasing concentrations of D-glucose (20%, 30%, 40% w/v using salt-adapted cells as inocula. We present evidence that osmostress induced by mild salt pre-treatments resulted in beneficial influences on both cell viability and fermentation performance of an industrial wine yeast strain.

  8. Evaluation Of Soursop Wine Produced With Baker's Yeast ...

    African Journals Online (AJOL)

    Evaluation Of Soursop Wine Produced With Baker's Yeast ( Saccharomyces cerevisae ) ... Journal of Agriculture and Food Sciences ... Soursop pulp was fermented for wine production using baker's yeast (S. cerevisiae) and the wine produced was evaluated using some wine quality parameters (pH, Titrable acidity (TA), ...

  9. Ethanol production potential of local yeast strains isolated from ripe ...

    African Journals Online (AJOL)

    STORAGESEVER

    2008-05-16

    May 16, 2008 ... has been Saccharomyces cerevisiae. This yeast also has the ability to produce ethanol which is not contaminated by other products from the substrate. Banana peels are readily available agricultural waste in. Nigeria, yet they seem to be underutilized as potential growth medium for local yeast strains, ...

  10. New yeast-based approaches in production of palmitoleic acid

    Czech Academy of Sciences Publication Activity Database

    Kolouchová, I.; Sigler, Karel; Schreiberová, O.; Masák, J.; Řezanka, Tomáš

    2015-01-01

    Roč. 192, SEP 2015 (2015), s. 726-734 ISSN 0960-8524 R&D Projects: GA ČR(CZ) GAP503/11/0215; GA ČR GA14-00227S Institutional support: RVO:61388971 Keywords : Oleaginous yeasts * Non-oleaginous yeasts * Palmitoleic acid Subject RIV: EE - Microbiology, Virology Impact factor: 4.917, year: 2015

  11. Antioxidant and Anticancer activities of yeast grown on commercial ...

    African Journals Online (AJOL)

    Media preparation. Three commercial media were prepared by weighting of 30 grams and cooked on hot plate then filtrated by cotton and sterilized in the autoclave at 121 °C for 20 min. while basal medium was prepared according to Chen et al. (2010), yeast- peptone-dextrose (YPD) broth containing. 0.5% (w ⁄v) yeast ...

  12. Electrospun chitosan/baker's yeast nanofibre adsorbent: preparation ...

    Indian Academy of Sciences (India)

    Many studies have shown the capability of baker's yeast (Saccharomyces cerevisiae) for heavy met- als removal, but less efforts are dedicated for application of ... Chitosan (75–85% deacetylated) with medium molecular weight and glutaraldehyde solution (25 wt%) were supplied by Sigma-Aldrich. The baker's yeast was ...

  13. Functional genomics of beer-related physiological processes in yeast

    NARCIS (Netherlands)

    Hazelwood, L.A.

    2009-01-01

    Since the release of the entire genome sequence of the S. cerevisiae laboratory strain S288C in 1996, many functional genomics tools have been introduced in fundamental and application-oriented yeast research. In this thesis, the applicability of functional genomics for the improvement of yeast in

  14. Occurrence and function of yeasts in Asian indigenous fermented foods

    NARCIS (Netherlands)

    Aidoo, K.E.; Nout, M.J.R.; Sarkar, P.K.

    2006-01-01

    In the Asian region, indigenous fermented foods are important in daily life. In many of these foods, yeasts are predominant and functional during the fermentation. The diversity of foods in which yeasts predominate ranges from leavened bread-like products such as nan and idli, to alcoholic beverages

  15. The effect of ruminal incubation of bioactive yeast ( Saccharomyces ...

    African Journals Online (AJOL)

    The rising interest in the use of organic and inorganic substances in manipulating rumen function for improved fermentative activity has provided avenues for the inclusion of various species of yeast cultures in ruminant diets. In this study, we investigated the effect of bioactive yeast (Saccharomyces cerevisiae), on rumen ...

  16. Phenotypic characters of yeasts isolated from kpete-kpete , a ...

    African Journals Online (AJOL)

    ... on their phenotypic characters and their assimilation profiles, 49 yeasts were isolated and found to belong to five genera with seven species. Seventy one percent (71%) of the isolates were identified as Saccharomyces cerevisiae. Key words: Sorghum beer, tchoukoutou, kpete-kpete, yeast, Saccharomyces cerevisiae.

  17. Anti-yeast activity of extracts and fractions from Uvariodendron ...

    African Journals Online (AJOL)

    The resistance to available antifungals highlights the urgent need for innovative drugs to treat yeasts infections. This study aimed at evaluating the activity of extracts and fractions from Uvariodendron calophyllum against pathogenic yeasts. The ethanolic and aqueous extracts obtained by maceration were liquidliquid- ...

  18. Improving industrial yeast strains: exploiting natural and artificial diversity

    Science.gov (United States)

    Steensels, Jan; Snoek, Tim; Meersman, Esther; Nicolino, Martina Picca; Voordeckers, Karin; Verstrepen, Kevin J

    2014-01-01

    Yeasts have been used for thousands of years to make fermented foods and beverages, such as beer, wine, sake, and bread. However, the choice for a particular yeast strain or species for a specific industrial application is often based on historical, rather than scientific grounds. Moreover, new biotechnological yeast applications, such as the production of second-generation biofuels, confront yeast with environments and challenges that differ from those encountered in traditional food fermentations. Together, this implies that there are interesting opportunities to isolate or generate yeast variants that perform better than the currently used strains. Here, we discuss the different strategies of strain selection and improvement available for both conventional and nonconventional yeasts. Exploiting the existing natural diversity and using techniques such as mutagenesis, protoplast fusion, breeding, genome shuffling and directed evolution to generate artificial diversity, or the use of genetic modification strategies to alter traits in a more targeted way, have led to the selection of superior industrial yeasts. Furthermore, recent technological advances allowed the development of high-throughput techniques, such as ‘global transcription machinery engineering’ (gTME), to induce genetic variation, providing a new source of yeast genetic diversity. PMID:24724938

  19. Specialist nectar-yeasts decline with urbanization in Berlin

    Science.gov (United States)

    Wehner, Jeannine; Mittelbach, Moritz; Rillig, Matthias C.; Verbruggen, Erik

    2017-03-01

    Nectar yeasts are common inhabitants of insect-pollinated flowers but factors determining their distribution are not well understood. We studied the influence of host identity, environmental factors related to pollution/urbanization, and the distance to a target beehive on local distribution of nectar yeasts within Robinia pseudoacacia L. and Tilia tomentosa Moench in Berlin, Germany. Nectar samples of six individuals per species were collected at seven sites in a 2 km radius from each target beehive and plated on YM-Agar to visualise the different morphotypes, which were then identified by sequencing a section of the 26S rDNA gene. Multivariate linear models were used to analyze the effects of all investigated factors on yeast occurrence per tree. Yeast distribution was mainly driven by host identity. The influence of the environmental factors (NO2, height of construction, soil sealing) strongly depended on the radius around the tree, similar to the distance of the sampled beehive. Incidence of specialist nectar-borne yeast species decreased with increasing pollution/urbanization index. Given that specialist yeast species gave way to generalist yeasts that have a reduced dependency on pollinators for between-flower dispersal, our results indicate that increased urbanization may restrict the movement of nectar-specialized yeasts, via limitations of pollinator foraging behavior.

  20. Transporter engineering in biomass utilization by yeast.

    Science.gov (United States)

    Hara, Kiyotaka Y; Kobayashi, Jyumpei; Yamada, Ryosuke; Sasaki, Daisuke; Kuriya, Yuki; Hirono-Hara, Yoko; Ishii, Jun; Araki, Michihiro; Kondo, Akihiko

    2017-11-01

    Biomass resources are attractive carbon sources for bioproduction because of their sustainability. Many studies have been performed using biomass resources to produce sugars as carbon sources for cell factories. Expression of biomass hydrolyzing enzymes in cell factories is an important approach for constructing biomass-utilizing bioprocesses because external addition of these enzymes is expensive. In particular, yeasts have been extensively engineered to be cell factories that directly utilize biomass because of their manageable responses to many genetic engineering tools, such as gene expression, deletion and editing. Biomass utilizing bioprocesses have also been developed using these genetic engineering tools to construct metabolic pathways. However, sugar input and product output from these cells are critical factors for improving bioproduction along with biomass utilization and metabolic pathways. Transporters are key components for efficient input and output activities. In this review, we focus on transporter engineering in yeast to enhance bioproduction from biomass resources. © FEMS 2017. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  1. Production of glycolipid biosurfactants by basidiomycetous yeasts.

    Science.gov (United States)

    Morita, Tomotake; Fukuoka, Tokuma; Imura, Tomohiro; Kitamoto, Dai

    2009-05-01

    BSs (biosurfactants) produced by various micro-organisms show unique properties (e.g. mild production conditions, lower toxicity, higher biodegradability and environmental compatibility) compared with chemically synthesized surfactants. The numerous advantages of BSs have prompted applications not only in the food, cosmetic and pharmaceutical industries but also in environmental protection and energy-saving technology. Among BSs, glycolipid types are the most promising, owing to their high productivity from renewable resources and versatile biochemical properties. MELs (mannosylerythritol lipids), which are glycolipid BSs abundantly produced by basidiomycetous yeasts such as strains of Pseudozyma, exhibit not only excellent interfacial properties, but also remarkable differentiation-inducing activities against human leukaemia cells. MELs also show high binding affinity towards different immunoglobulins and lectins. Recently, a cationic liposome bearing MEL has been demonstrated to increase dramatically the efficiency of gene transfection into mammalian cells. These features of BSs should broaden their application in new advanced technologies. In the present review the current status of research and development on glycolipid BSs, especially their production by Pseudozyma yeasts, is described.

  2. Mechanics of cell division in fission yeast

    Science.gov (United States)

    Chang, Fred

    2012-02-01

    Cytokinesis is the stage of cell division in which a cell divides into two. A paradigm of cytokinesis in animal cells is that the actomyosin contractile ring provides the primary force to squeeze the cell into two. In the fission yeast Schizosaccharomyces pombe, cytokinesis also requires a actomyosin ring, which has been generally assumed to provide the force for cleavage. However, in contrast to animal cells, yeast cells assemble a cell wall septum concomitant with ring contraction and possess large (MPa) internal turgor pressure. Here, we show that the inward force generated by the division apparatus opposes turgor pressure; a decrease in effective turgor pressure leads to an increase in cleavage rate. We show that the ring cannot be the primary force generator. Scaling arguments indicate that the contractile ring can only provide a tiny fraction of the mechanical stress required to overcome turgor. Further, we show that cleavage can occur even in the absence of the contractile ring. Instead of the contractile ring, scaling arguments and modeling suggest that the large forces for cytokinesis are produced by the assembly of cell wall polymers in the growing septum.

  3. Selection of Xilose-Fermenting Yeast Strains

    Directory of Open Access Journals (Sweden)

    Rosimeire Oenning da Silva

    Full Text Available ABSTRACT In Brazil, ethanol is obtained by fermentat of sugar cane juice using Saccharomyces cerevisiae. The cane juice extraction generates the bagasse that has been used for obtaining generation biofuel. However, the sugarcane bagasse has 30% pentose that cannot be fermented to ethanol by S. cerevisiae. Thus the aim of this study was to isolate a yeast able to ferment xylose to ethanol. Samples of cane juice and flowers were used for the isolation of 165 strains that were then screened for ethanol production using plate testing. Among them, the ethanol positive strains Wickerhamomyces anomalus, Schizosaccharomyces pombe and Starmerella meliponinorum were selected for a xylose fermentation assay, using a semi-synthetic and bagasse hydrolysate as must. S. meliponinorum and S. pombe produced 0.63 and 2.7 gL-1 of ethanol, respectively, from xylose in a semisynthetic medium. In the medium consisting of bagasse hydrolysate must, 0.67 and 1.1 gL-1 of ethanol were obtained from S. meliponinorum and S. pombe, respectively. All the yeasts produced xylitol from xylose in the semisynthetic medium and S. meliponinorum was that which produced the highest quantity (14.5 g L-1.

  4. Signaling pathways of replication stress in yeast.

    Science.gov (United States)

    Pardo, Benjamin; Crabbé, Laure; Pasero, Philippe

    2017-03-01

    Eukaryotic cells activate the S-phase checkpoint in response to a variety of events affecting the progression of replication forks, collectively referred to as replication stress. This signaling pathway is divided in two branches: the DNA damage checkpoint (DDC) and the DNA replication checkpoint (DRC). Both pathways are activated by the sensor kinase Mec1 and converge on the effector kinase Rad53. However, the DDC operates throughout the cell cycle and depends on the checkpoint mediator Rad9 to activate Rad53, whereas the DRC is specific to S phase and is mediated by Mrc1 and other fork components to signal replication impediments. In this review, we summarize current knowledge on these two pathways, with a focus on the budding yeast Saccharomyces cerevisiae, in which many important aspects of the replication stress response were discovered. We also discuss the differences and similarities between DDC and DRC and speculate on how these pathways cooperate to ensure the complete and faithful duplication of the yeast genome under various replication stress conditions. © FEMS 2016. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  5. Perchlorate Reduction by Yeast for Mars Exploration

    Science.gov (United States)

    Sharma, Alaisha

    2015-01-01

    Martian soil contains high levels (0.6 percentage by mass) of calcium perchlorate (Ca(ClO4)2), which readily dissociates into calcium and the perchlorate ion (ClO4-) in water. Even in trace amounts, perchlorates are toxic to humans and have been implicated in thyroid dysfunction. Devising methods to lessen perchlorate contamination is crucial to minimizing the health risks associated with human exploration and colonization of Mars. We designed a perchlorate reduction pathway, which sequentially reduces perchlorate to chloride (Cl-) and oxygen (O2), for implementation in the yeast Saccharomyces cerevisiae. Using genes obtained from perchlorate reducing bacteria Azospira oryzae and Dechloromonas aromatica, we plan to assemble this pathway directly within S. cerevisiae through recombinational cloning. A perchlorate reduction pathway would enable S. cerevisiae to lower perchlorate levels and produce oxygen, which may be harvested or used directly by S. cerevisiae for aerobic growth and compound synthesis. Moreover, using perchlorate as an external electron acceptor could improve the efficiency of redox-imbalanced production pathways in yeast. Although several perchlorate reducing bacteria have been identified and utilized in water treatment systems on Earth, the widespread use of S. cerevisiae as a synthetic biology platform justifies the development of a perchlorate reducing strain for implementation on Mars.

  6. Thermotolerant yeasts and application for ethanol production

    Directory of Open Access Journals (Sweden)

    To-on, N.

    2007-07-01

    Full Text Available A total of 70 thermotolerant yeast strains were isolated at 40oC from 145 samples including fruit, leaves, flowers, soils and oil-palm fruits. Six isolates showed maximum growth at 40oC within 18 h. Three isolates (MIY1, MIY48 and MIY57 were selected based on their ability to ferment glucose and sucrose rapidly (24 h and showed the maximum temperature for growth at 42oC but it was good at 40oC. MIY57 produced 4.6% (v/v ethanol at 40oC from a medium containing 15% glucose. The optimum cultivation conditions for growth and ethanol production of MIY57 was 5% inoculum into the fermentation medium containing 15% glucose and 1% yeast extract with initial pH of 4.5 on a shaking incubator at 150 rpm at 40oC. MIY57, under these conditions, produced maximum ethanol of 5.0% (v/v after 48 h incubation while S. cerevisiae TISTR 5048 produced only 3.7% (v/v. Maximum cell dry weight was 7.2 g/L (at 18 h, again much higher than that of S. cerevisiae TISTR 5048 (4.1 g/L. Based on morphological, physiological and molecular studies, this strain (MIY57 was identified as Saccharomyces cerevisiae.

  7. Nanomechanics of Yeast Surfaces Revealed by AFM

    Science.gov (United States)

    Dague, Etienne; Beaussart, Audrey; Alsteens, David

    Despite the large and well-documented characterization of the microbial cell wall in terms of chemical composition, the determination of the mechanical properties of surface molecules in relation to their function remains a key challenge in cell biology.The emergence of powerful tools allowing molecular manipulations has already revolutionized our understanding of the surface properties of fungal cells. At the frontier between nanophysics and molecular biology, atomic force microscopy (AFM), and more specifically single-molecule force spectroscopy (SMFS), has strongly contributed to our current knowledge of the cell wall organization and nanomechanical properties. However, due to the complexity of the technique, measurements on live cells are still at their infancy.In this chapter, we describe the cell wall composition and recapitulate the principles of AFM as well as the main current methodologies used to perform AFM measurements on live cells, including sample immobilization and tip functionalization.The current status of the progress in probing nanomechanics of the yeast surface is illustrated through three recent breakthrough studies. Determination of the cell wall nanostructure and elasticity is presented through two examples: the mechanical response of mannoproteins from brewing yeasts and elasticity measurements on lacking polysaccharide mutant strains. Additionally, an elegant study on force-induced unfolding and clustering of adhesion proteins located at the cell surface is also presented.

  8. Copper exposure effects on yeast mitochondrial proteome.

    Science.gov (United States)

    Banci, Lucia; Bertini, Ivano; Ciofi-Baffoni, Simone; D'Alessandro, Annamaria; Jaiswal, Deepa; Marzano, Valeria; Neri, Sara; Ronci, Maurizio; Urbani, Andrea

    2011-10-19

    Mitochondria play an important role on the entire cellular copper homeostatic mechanisms. Alteration of cellular copper levels may thus influence mitochondrial proteome and its investigation represents an important contribution to the general understanding of copper-related cellular effects. In these study we have performed an organelle targeted proteomic investigation focusing our attention on the effect of non-lethal 1mM copper concentration on Saccharomyces cerevisiae mitochondrial proteome. Functional copper effects on yeast mitochondrial proteome were evaluated by using both 2D electrophoresis (2-DE) and liquid chromatography coupled with tandem mass spectrometry. Proteomic data have been then analyzed by different unsupervised meta-analysis approaches that highlight the impairment of mitochondrial functions and the activation of oxidative stress response. Interestingly, our data have shown that stress response generated by 1mM copper treatment determines the activation of S. cerevisiae survival pathway. To investigate these findings we have treated yeast cells responsiveness to copper with hydrogen peroxide and observed a protective role of this metal. These results are suggestive of a copper role in the protection from oxidative stress possibly due to the activation of mechanisms involved in cellular survival and growth. Copyright © 2011 Elsevier B.V. All rights reserved.

  9. Parameters affecting methanol utilization by yeasts

    Energy Technology Data Exchange (ETDEWEB)

    Foda, M.S.; El-Masry, H.G.

    1981-01-01

    Screening of 28 yeast cultures, representing 22 species of various yeasts, with respect to their capabilities to assimilate methanol, has shown that this property was mostly found in certain species of the two genera Hansenula and Candida. When methanol was used as a sole carbon source for a methanol-adapted strain of Hansenula polymorpha, a linear yield response could be obtained with increasing alcohol up to 2% concentration. The amount of inoculum proved to be the decisive factor in determining a priori the ability of the organism to grow at 6% methanol as final concentration. The optimum pH values for growth ranged between 4.5-5.5 with no growth at pH 6.5 or higher. A marked growth stimulation was obtained when the medium was supplied with phosphate up to 0.08 M as final concentration. Within the nitrogen sources tested, corn steep liquor concentrate gave the highest yield of cells. The significance of the obtained results are discussed with reference to feasibilities of application.

  10. Building terpene production platforms in yeast.

    Science.gov (United States)

    Zhuang, Xun; Chappell, Joe

    2015-09-01

    Plants and microbes commonly make terpenes and terpenoids in small amounts and as complex mixtures, and their chemical synthesis is often costly and inefficient. Hence, there are many efforts to create robust and efficient biological production platforms for this interesting class of molecules. In this study, our effort was directed towards building a yeast production platform using an unbiased genetic selection approach. Yeast strain BY4741 was subjected to EMS mutagenesis, followed by selection for growth in the presence of nystatin, squalestatin, and exogenous cholesterol. This unbiased screen selected for mutant yeast lines having a dispensable mevalonate pathway and containing uncharacterized SUE (sterol uptake enhancement) mutations supporting aerobic uptake of exogenous sterol. These mutants were next screened for high level accumulation of farnesol (FOH), an indicator for high level accumulation of the key intermediate FPP, farnesyl diphosphate. To further improve the FPP pool in these mutants, insertional mutations into the ERG9 gene (coding for squalene synthase) were introduced into those lines capable of accumulating ≥50 mg farnesol/L. This generated another series of lines that accumulated farnesol levels over 70 mg/L in small-scale shake cultures. To evaluate the utility of these lines as a general production platform for specific terpenes, select SUE/erg9 lines were transformed with a vector harboring the Hyoscyamus muticus premnaspirodiene synthase (HPS) gene encoding for a sesquiterpene synthase. The new yeast line ZX178-08 accumulated the highest level of premnaspirodiene, up to 116 mg/L, with FOH levels of 23.6 mg/L. In comparison, the parental line BY4741 accumulated 10 times less premnaspirodiene, 10.94 mg/L, with no farnesol detectable. Co-expression of the HPS gene with an amino-terminal truncated, catalytic form of the hamster HMGR gene, tHMGR, increased premnaspirodiene accumulation to 170.23 ± 30.44 mg/L, almost a 50

  11. New lager yeast strains generated by interspecific hybridization.

    Science.gov (United States)

    Krogerus, Kristoffer; Magalhães, Frederico; Vidgren, Virve; Gibson, Brian

    2015-05-01

    The interspecific hybrid Saccharomyces pastorianus is the most commonly used yeast in brewery fermentations worldwide. Here, we generated de novo lager yeast hybrids by mating a domesticated and strongly flocculent Saccharomyces cerevisiae ale strain with the Saccharomyces eubayanus type strain. The hybrids were characterized with respect to the parent strains in a wort fermentation performed at temperatures typical for lager brewing (12 °C). The resulting beers were analysed for sugar and aroma compounds, while the yeasts were tested for their flocculation ability and α-glucoside transport capability. These hybrids inherited beneficial properties from both parent strains (cryotolerance, maltotriose utilization and strong flocculation) and showed apparent hybrid vigour, fermenting faster and producing beer with higher alcohol content (5.6 vs 4.5 % ABV) than the parents. Results suggest that interspecific hybridization is suitable for production of novel non-GM lager yeast strains with unique properties and will help in elucidating the evolutionary history of industrial lager yeast.

  12. Yeast diversity and native vigor for flavor phenotypes.

    Science.gov (United States)

    Carrau, Francisco; Gaggero, Carina; Aguilar, Pablo S

    2015-03-01

    Saccharomyces cerevisiae, the yeast used widely for beer, bread, cider, and wine production, is the most resourceful eukaryotic model used for genetic engineering. A typical concern about using engineered yeasts for food production might be negative consumer perception of genetically modified organisms. However, we believe the true pitfall of using genetically modified yeasts is their limited capacity to either refine or improve the sensory properties of fermented foods under real production conditions. Alternatively, yeast diversity screening to improve the aroma and flavors could offer groundbreaking opportunities in food biotechnology. We propose a 'Yeast Flavor Diversity Screening' strategy which integrates knowledge from sensory analysis and natural whole-genome evolution with information about flavor metabolic networks and their regulation. Copyright © 2015 Elsevier Ltd. All rights reserved.

  13. The role of red yeast rice for the physician.

    Science.gov (United States)

    Gordon, Ram Y; Becker, David J

    2011-02-01

    Red yeast rice is an ancient Chinese dietary staple and medication used by millions of patients as an alternative therapy for hypercholesterolemia. In recent years, the use of red yeast rice has grown exponentially due to increased public interest in complementary and alternative medications and the publication of several randomized, controlled trials demonstrating its efficacy and safety in different populations. The most promising role for red yeast rice is as an alternative lipid-lowering therapy for patients who refuse to take statins because of philosophical reasons or patients who are unable to tolerate statin therapy due to statin-associated myalgias. However, there is limited government oversight of red yeast rice products, wide variability of active ingredients in available formulations, and the potential of toxic byproducts. Therefore, until red yeast rice products are regulated and standardized, physicians and patients should be cautious in recommending this promising alternative therapy for hyperlipidemia.

  14. PMAA-stabilized ferrofluid/chitosan/yeast composite for bioapplications

    Energy Technology Data Exchange (ETDEWEB)

    Baldikova, Eva, E-mail: baldie@email.cz [Global Change Research Institute, CAS, Na Sadkach 7, 370 05 Ceske Budejovice (Czech Republic); Department of Applied Chemistry, Faculty of Agriculture, University of South Bohemia, Branisovska 1457, 370 05 Ceske Budejovice (Czech Republic); Prochazkova, Jitka [Global Change Research Institute, CAS, Na Sadkach 7, 370 05 Ceske Budejovice (Czech Republic); Stepanek, Miroslav; Hajduova, Jana [Department of Physical and Macromolecular Chemistry, Faculty of Science, Charles University, Hlavova 2030, 128 40 Prague 2 (Czech Republic); Pospiskova, Kristyna [Regional Centre of Advanced Technologies and Materials, Palacky University, Slechtitelu 27, 783 71 Olomouc (Czech Republic); Safarikova, Mirka [Global Change Research Institute, CAS, Na Sadkach 7, 370 05 Ceske Budejovice (Czech Republic); Department of Nanobiotechnology, Biology Centre, CAS, ISB, Na Sadkach 7, 370 05 Ceske Budejovice (Czech Republic); Safarik, Ivo [Global Change Research Institute, CAS, Na Sadkach 7, 370 05 Ceske Budejovice (Czech Republic); Regional Centre of Advanced Technologies and Materials, Palacky University, Slechtitelu 27, 783 71 Olomouc (Czech Republic); Department of Nanobiotechnology, Biology Centre, CAS, ISB, Na Sadkach 7, 370 05 Ceske Budejovice (Czech Republic)

    2017-04-01

    A simple, one-pot process for the preparation of magnetically responsive yeast-based biocatalysts was developed. Saccharomyces cerevisiae, Candida utilis and Kluyveromyces lactis cells were successfully incorporated into chitosan gel magnetically modified with poly(methacrylic acid)-stabilized magnetic fluid (PMAA-FF) during its formation. Magnetic PMAA-FF/chitosan/yeast composites were efficiently employed for invert sugar production. The dependence of invertase activity on used yeast, amount of magnetic biocatalyst, agitation time and after reuse was studied in detail. The tested magnetic biocatalysts retained at least 69% of their initial activity after 8 reuse cycles. - Highlights: • New types of magnetically responsive yeast biocomposites were prepared. • Recently developed PMAA-stabilized magnetic fluid was used. • Three yeast species were entrapped into magnetic chitosan gel during its formation. • All biocatalysts were efficiently employed for invert sugar formation.

  15. Tolerance of budding yeast Saccharomyces cerevisiae to ultra high pressure

    Science.gov (United States)

    Shibata, M.; Torigoe, M.; Matsumoto, Y.; Yamamoto, M.; Takizawa, N.; Hada, Y.; Mori, Y.; Takarabe, K.; Ono, F.

    2014-05-01

    Our studies on the tolerance of plants and animals against very high pressure of several GPa have been extended to a smaller sized fungus, the budding yeast Saccharomyces cerevisiae. Several pieces of budding yeast (dry yeast) were sealed in a small teflon capsule with a liquid pressure medium fluorinate, and exposed to 7.5 GPa by using a cubic anvil press. The pressure was kept constant for various duration of time from 2 to 24 h. After the pressure was released, the specimens were brought out from the teflon capsule, and they were cultivated on a potato dextrose agar. It was found that the budding yeast exposed to 7.5 GPa for up to 6 h showed multiplication. However, those exposed to 7.5 GPa for longer than 12 h were found dead. The high pressure tolerance of budding yeast is a little weaker than that of tardigrades.

  16. Antimicrobial activity of yeasts against some pathogenic bacteria

    Directory of Open Access Journals (Sweden)

    Gamal Younis

    2017-08-01

    Full Text Available Aim: This study was designed to isolate and identify yeast species from milk and meat products, and to test their antimicrobial activity against some bacterial species. Materials and Methods: A total of 160 milk and meat products samples were collected from random sellers and super markets in New Damietta city, Damietta, Egypt. Samples were subjected to yeast isolation procedures and tested for its antimicrobial activity against Staphylococcus aureus, Pseudomonas aeruginosa, and Escherichia coli. In addition, all yeast species isolates were subjected to polymerase chain reaction (PCR for detection of khs (kievitone hydratase and pelA (pectate degrading enzyme genes. Results: The recovery rate of yeasts from sausage was 20% (2/10 followed by kareish cheese, processed cheese, and butter 10% (1/10 each as well as raw milk 9% (9/100, and fruit yoghurt 30% (6/20. Different yeast species were recovered, namely, Candida kefyr (5 isolates, Saccharomyces cerevisiae (4 isolates, Candida intermedia (3 isolates, Candida tropicalis (2 isolates, Candida lusitaniae (2 isolates, and Candida krusei (1 isolate. khs gene was detected in all S. cerevisiae isolates, however, pelA gene was not detected in all identified yeast species. Antimicrobial activity of recovered yeasts against the selected bacterial species showed high activity with C. intermedia against S. aureus and E. coli, C. kefyr against E. coli, and C. lusitaniae against S. aureus. Moderate activities were obtained with C. tropicalis, C. lusitaniae, and S. cerevisiae against E. coli; meanwhile, all the tested yeasts revealed a very low antimicrobial activity against P. aeruginosa. Conclusion: The obtained results confirmed that some kinds of yeasts have the ability to produce antimicrobial compounds that could inhibit some pathogenic and spoilage bacteria and these antimicrobial activity of yeasts enables them to be one of the novel agents in controlling spoilage of food.

  17. Lipid raft involvement in yeast cell growth and death

    Directory of Open Access Journals (Sweden)

    Faustino eMollinedo

    2012-10-01

    Full Text Available The notion that cellular membranes contain distinct microdomains, acting as scaffolds for signal transduction processes, has gained considerable momentum. In particular, a class of such domains that is rich in sphingolipids and cholesterol, termed as lipid rafts, is thought to compartmentalize the plasma membrane, and to have important roles in survival and cell death signaling in mammalian cells. Likewise, yeast lipid rafts are membrane domains enriched in sphingolipids and ergosterol, the yeast counterpart of mammalian cholesterol. Sterol-rich membrane domains have been identified in several fungal species, including the budding yeast Saccharomyces cerevisiae, the fission yeast Schizosaccharomyces pombe as well as the pathogens Candida albicans and Crytococcus neoformans. Yeast rafts have been mainly involved in membrane trafficking, but increasing evidence implicates rafts in a wide range of additional cellular processes. Yeast lipid rafts house biologically important proteins involved in the proper function of yeast, such as proteins that control Na+, K+ and pH homeostasis, which influence many cellular processes, including cell growth and death. Membrane raft constituents affect drug susceptibility, and drugs interacting with sterols alter raft composition and membrane integrity, leading to yeast cell death. Because of the genetic tractability of yeast, analysis of yeast rafts could be an excellent model to approach unanswered questions of mammalian raft biology, and to understand the role of lipid rafts in the regulation of cell death and survival in human cells. A better insight in raft biology might lead to envisage new raft-mediated approaches to the treatment of human diseases where regulation of cell death and survival is critical, such as cancer and neurodegenerative diseases.

  18. Yeast species associated with wine grapes in China.

    Science.gov (United States)

    Li, Shuang-Shi; Cheng, Chao; Li, Zheng; Chen, Jing-Yu; Yan, Bin; Han, Bei-Zhong; Reeves, Malcolm

    2010-03-31

    Having more information on the yeast ecology of grapes is important for wine-makers to produce wine with high quality and typical attributes. China is a significant wine-consuming country and is becoming a serious wine-producer, but little has been reported about the yeast ecology of local ecosystems. This study provides the first step towards the exploitation of the yeast wealth in China's vine-growing regions. The aim of this study was to investigate the yeast population density and diversity on three grape varieties cultivated in four representative vine-growing regions of China. Yeast species diversity was evaluated by using polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) and sequence analysis of the 5.8S internal transcribed spacer (ITS) ribosomal DNA (rDNA) region of cultivable yeasts. The grapes harbored yeast populations at 10(2)-10(6)CFU/mL, consisting mostly of non-Saccharomyces species. Seventeen different yeast species belonging to eight genera were detected on the grape samples tested, including Hanseniaspora uvarum, Cryptococcus flavescens, Pichia fermentans, Candida zemplinina, Cryptococcus carnescens, Candida inconpicua, Zygosaccharomyces fermentati, Issatchenkia terricola, Candida quercitrusa, Hanseniaspora guilliermondii, Candida bombi, Zygosaccharomyces bailii, Sporidiobolus pararoseus, Cryptococcus magnus, Metschnikowia pulcherrima, Issatchenkia orientalis and Pichia guilliermondii. H. uvarum and C. flavescens were the dominant species present on the grapes. For the first time Sporidiobolus pararoseus was discovered as an inhabitant of the grape ecosystem. The yeast community on grape berries was influenced by the grape chemical composition, vine-variety and vine-growing region. This study is the first to identify the yeast communities associated with grapes in China using molecular methods. The results enrich our knowledge of wine-related microorganisms, and can be used to promote the development of the local wine

  19. Performance of non-conventional yeasts in co-culture with brewers’ yeast for steering ethanol and aroma production

    NARCIS (Netherlands)

    Rijswijck, van Irma M.H.; Wolkers - Rooijackers, Judith C.M.; Abee, Tjakko; Smid, Eddy J.

    2017-01-01

    Increasing interest in new beer types has stimulated the search for approaches to extend the metabolic variation of brewers’ yeast. Therefore, we tested two approaches using non-conventional yeast to create a beer with lower ethanol content and a complex aroma bouquet. First, the mono-culture

  20. Introducing a new breed of wine yeast: interspecific hybridisation between a commercial Saccharomyces cerevisiae wine yeast and Saccharomyces mikatae.

    Directory of Open Access Journals (Sweden)

    Jennifer R Bellon

    Full Text Available Interspecific hybrids are commonplace in agriculture and horticulture; bread wheat and grapefruit are but two examples. The benefits derived from interspecific hybridisation include the potential of generating advantageous transgressive phenotypes. This paper describes the generation of a new breed of wine yeast by interspecific hybridisation between a commercial Saccharomyces cerevisiae wine yeast strain and Saccharomyces mikatae, a species hitherto not associated with industrial fermentation environs. While commercially available wine yeast strains provide consistent and reliable fermentations, wines produced using single inocula are thought to lack the sensory complexity and rounded palate structure obtained from spontaneous fermentations. In contrast, interspecific yeast hybrids have the potential to deliver increased complexity to wine sensory properties and alternative wine styles through the formation of novel, and wider ranging, yeast volatile fermentation metabolite profiles, whilst maintaining the robustness of the wine yeast parent. Screening of newly generated hybrids from a cross between a S. cerevisiae wine yeast and S. mikatae (closely-related but ecologically distant members of the Saccharomyces sensu stricto clade, has identified progeny with robust fermentation properties and winemaking potential. Chemical analysis showed that, relative to the S. cerevisiae wine yeast parent, hybrids produced wines with different concentrations of volatile metabolites that are known to contribute to wine flavour and aroma, including flavour compounds associated with non-Saccharomyces species. The new S. cerevisiae x S. mikatae hybrids have the potential to produce complex wines akin to products of spontaneous fermentation while giving winemakers the safeguard of an inoculated ferment.

  1. Introducing a new breed of wine yeast: interspecific hybridisation between a commercial Saccharomyces cerevisiae wine yeast and Saccharomyces mikatae.

    Science.gov (United States)

    Bellon, Jennifer R; Schmid, Frank; Capone, Dimitra L; Dunn, Barbara L; Chambers, Paul J

    2013-01-01

    Interspecific hybrids are commonplace in agriculture and horticulture; bread wheat and grapefruit are but two examples. The benefits derived from interspecific hybridisation include the potential of generating advantageous transgressive phenotypes. This paper describes the generation of a new breed of wine yeast by interspecific hybridisation between a commercial Saccharomyces cerevisiae wine yeast strain and Saccharomyces mikatae, a species hitherto not associated with industrial fermentation environs. While commercially available wine yeast strains provide consistent and reliable fermentations, wines produced using single inocula are thought to lack the sensory complexity and rounded palate structure obtained from spontaneous fermentations. In contrast, interspecific yeast hybrids have the potential to deliver increased complexity to wine sensory properties and alternative wine styles through the formation of novel, and wider ranging, yeast volatile fermentation metabolite profiles, whilst maintaining the robustness of the wine yeast parent. Screening of newly generated hybrids from a cross between a S. cerevisiae wine yeast and S. mikatae (closely-related but ecologically distant members of the Saccharomyces sensu stricto clade), has identified progeny with robust fermentation properties and winemaking potential. Chemical analysis showed that, relative to the S. cerevisiae wine yeast parent, hybrids produced wines with different concentrations of volatile metabolites that are known to contribute to wine flavour and aroma, including flavour compounds associated with non-Saccharomyces species. The new S. cerevisiae x S. mikatae hybrids have the potential to produce complex wines akin to products of spontaneous fermentation while giving winemakers the safeguard of an inoculated ferment.

  2. Introducing a New Breed of Wine Yeast: Interspecific Hybridisation between a Commercial Saccharomyces cerevisiae Wine Yeast and Saccharomyces mikatae

    Science.gov (United States)

    Bellon, Jennifer R.; Schmid, Frank; Capone, Dimitra L.; Dunn, Barbara L.; Chambers, Paul J.

    2013-01-01

    Interspecific hybrids are commonplace in agriculture and horticulture; bread wheat and grapefruit are but two examples. The benefits derived from interspecific hybridisation include the potential of generating advantageous transgressive phenotypes. This paper describes the generation of a new breed of wine yeast by interspecific hybridisation between a commercial Saccharomyces cerevisiae wine yeast strain and Saccharomyces mikatae, a species hitherto not associated with industrial fermentation environs. While commercially available wine yeast strains provide consistent and reliable fermentations, wines produced using single inocula are thought to lack the sensory complexity and rounded palate structure obtained from spontaneous fermentations. In contrast, interspecific yeast hybrids have the potential to deliver increased complexity to wine sensory properties and alternative wine styles through the formation of novel, and wider ranging, yeast volatile fermentation metabolite profiles, whilst maintaining the robustness of the wine yeast parent. Screening of newly generated hybrids from a cross between a S. cerevisiae wine yeast and S. mikatae (closely-related but ecologically distant members of the Saccharomyces sensu stricto clade), has identified progeny with robust fermentation properties and winemaking potential. Chemical analysis showed that, relative to the S. cerevisiae wine yeast parent, hybrids produced wines with different concentrations of volatile metabolites that are known to contribute to wine flavour and aroma, including flavour compounds associated with non-Saccharomyces species. The new S. cerevisiae x S. mikatae hybrids have the potential to produce complex wines akin to products of spontaneous fermentation while giving winemakers the safeguard of an inoculated ferment. PMID:23614011

  3. Biocavity laser spectroscopy of genetically altered yeast cells and isolated yeast mitochondria

    Science.gov (United States)

    Gourley, Paul L.; Hendricks, Judy K.; McDonald, Anthony E.; Copeland, R. Guild; Naviaux, Robert K.; Yaffe, Michael P.

    2006-02-01

    We report an analysis of 2 yeast cell mutants using biocavity laser spectroscopy. The two yeast strains differed only by the presence or absence of mitochondrial DNA. Strain 104 is a wild-type (ρ +) strain of the baker's yeast, Saccharomyces cerevisiae. Strain 110 was derived from strain 104 by removal of its mitochondrial DNA (mtDNA). Removal of mtDNA causes strain 110 to grow as a "petite" (ρ -), named because it forms small colonies (of fewer cells because it grows more slowly) on agar plates supplemented with a variety of different carbon sources. The absence of mitochondrial DNA results in the complete loss of all the mtDNA-encoded proteins and RNAs, and loss of the pigmented, heme-containing cytochromes a and b. These cells have mitochondria, but the mitochondria lack the normal respiratory chain complexes I, III, IV, and V. Complex II is preserved because its subunits are encoded by genes located in nuclear DNA. The frequency distributions of the peak shifts produced by wild-type and petite cells and mitochondria show striking differences in the symmetry and patterns of the distributions. Wild-type ρ + cells (104) and mitochondria produced nearly symmetric, Gaussian distributions. The ρ - cells (110) and mitochondria showed striking asymmetry and skew that appeared to follow a Poisson distribution.

  4. Import of proteins into isolated yeast mitochondria.

    Science.gov (United States)

    Peleh, Valentina; Ramesh, Ajay; Herrmann, Johannes M

    2015-01-01

    Mitochondria are essential organelles of eukaryotic cells. The vast majority of mitochondrial proteins is encoded within the nuclear genome and translocated into various mitochondrial compartments after translation in the cytosol as preproteins. Even in rather primitive eukaryotes like yeasts, there are 700-1,000 different proteins that need to be recognized in the cytosol, directed to the protein translocases in the two mitochondrial membranes and sorted to their appropriate mitochondrial subcompartment. In vitro reconstituted import systems have proved to be important tools to study these processes in detail. Using isolated mitochondria and radioactively labeled precursor proteins, it was possible to identify several import machineries and pathways consisting of a large number of components during the last few decades.

  5. Immunosuppressive decalin derivatives from red yeast rice.

    Science.gov (United States)

    Zhu, Lin; Lu, Jing-Guang; Li, Ting; Zhu, Guo-Yuan; Han, Quan-Bin; Hsiao, Wen-Luan; Liu, Liang; Jiang, Zhi-Hong

    2012-04-27

    Five new decalin derivatives (1-5), together with two known compounds (6 and 7), were isolated from the ethyl acetate extract of red yeast rice. Their structures were elucidated by means of NMR and mass spectroscopic analyses. Monascusic lactone A (1) is the first reported naturally occurring decalin derivative possessing a spiro lactone at the C-1 position. The immunosuppressive effects of all these isolates (1-7) on human T cell proliferation were investigated, and all, especially monascusic acids B (2), C (3), D (4), and A (6) and heptaketide (7), suppressed human T cell proliferation in a dose-dependent manner from 10 to 100 μM. This is the first report on the immunosuppressive activity of decalin derivatives. © 2012 American Chemical Society and American Society of Pharmacognosy

  6. Debaryomyces hansenii: An Osmotolerant and Halotolerant Yeast

    Science.gov (United States)

    Aggarwal, Monika; Mondal, Alok K.

    The yeast Debaryomyces hansenii which was isolated from saline environments such as sea water, concentrated brines, salty food, is one of the most halotolerant species. It can grow in media containing as high as 4 M NaCl, while the growth of Saccharomyces cerevisiae is limited in media with more than 1.7 M NaCl. This species is very important for food industry as it is used for surface ripening of cheese and meat products. In the recent past, there is growing interest in understanding the molecular mechanisms of high halotolerance exhibited by D. hansenii. Availability of genome sequence of D. hansenii has opened up new vistas in this direction

  7. Chromosome Dynamics in the Yeast Interphase Nucleus

    Science.gov (United States)

    Heun, Patrick; Laroche, Thierry; Shimada, Kenji; Furrer, Patrick; Gasser, Susan M.

    2001-12-01

    Little is known about the dynamics of chromosomes in interphase nuclei. By tagging four chromosomal regions with a green fluorescent protein fusion to lac repressor, we monitored the movement and subnuclear position of specific sites in the yeast genome, sampling at short time intervals. We found that early and late origins of replication are highly mobile in G1 phase, frequently moving at or faster than 0.5 micrometers/10 seconds, in an energy-dependent fashion. The rapid diffusive movement of chromatin detected in G1 becomes constrained in S phase through a mechanism dependent on active DNA replication. In contrast, telomeres and centromeres provide replication-independent constraint on chromatin movement in both G1 and S phases.

  8. Analyzing DNA replication checkpoint in budding yeast.

    Science.gov (United States)

    Hustedt, Nicole; Shimada, Kenji

    2014-01-01

    Checkpoints are conserved mechanisms that prevent progression into the next phase of the cell cycle when cells are unable to accomplish the previous event properly. Cells also possess a surveillance mechanism called the DNA replication checkpoint, which consists of a conserved kinase cascade that is provoked by insults that block or slow down replication fork progression. In the budding yeast Saccharomyces cerevisiae, the DNA replication checkpoint controls the timing of S-phase events such as origin firing and spindle elongation. This checkpoint also upregulates dNTP pools and maintains the replication fork structure in order to resume DNA replication after replication block. Many replication checkpoint factors have been found to be tumor suppressors, highlighting the importance of this checkpoint pathway in human health. Here we describe a series of protocols to analyze the DNA replication checkpoint in S. cerevisiae.

  9. Beneficial properties of probiotic yeast Saccharomyces boulardii

    Directory of Open Access Journals (Sweden)

    Tomičić Zorica M.

    2016-01-01

    Full Text Available Saccharomyces boulardii is unique probiotic and biotherapeutic yeast, known to survive in gastric acidity and it is not adversely affected or inhibited by antibiotics or does not alter or adversely affect the normal microbiota. S. boulardii has been utilized worldwide as a probiotic supplement to support gastrointestinal health. The multiple mechanisms of action of S. boulardii and its properties may explain its efficacy and beneficial effects in acute and chronic gastrointestinal diseases that have been confirmed by clinical trials. Caution should be taken in patients with risk factors for adverse events. Its potential application in various dairy foods could offer an alternative probiotic product to people suffering from antibiotic-associated diarrhea. This review discusses the evidence for efficacy and safety of S. boulardii as a probiotic for the prevention and therapy of gastrointestinal disorders in humans.

  10. Identification and characterization of yeasts in sugarcane silages.

    Science.gov (United States)

    Avila, C L S; Bravo Martins, C E C; Schwan, R F

    2010-11-01

    To enumerate the micro-organisms and to identify the yeast species present during the ensilage of different sugarcane (Saccharum spp.) cultivars. Samples of sugarcane silage were collected at 10, 20, 30 and 40 days from the start of fermentation. Population levels of lactic acid bacteria (LAB), mesophilic facultative anaerobic (MFA) bacteria, filamentous fungi and yeasts were determined. Nine species of yeasts were classified according to traditional methods and confirmed using molecular techniques. LAB dominated the ensiling process of sugarcane, although yeasts were present at relatively high population levels throughout the whole fermentation period. The detected species of yeasts varied according to sugarcane cultivar and time of fermentation. Torulaspora delbrueckii was the predominant yeast, followed by Pichia anomala and Saccharomyces cerevisiae. Knowledge of the population of micro-organisms in general, and of yeasts in particular, present during the fermentation of sugarcane is of fundamental importance in the development of more effective ensiling processes. © 2010 The Authors. Journal of Applied Microbiology © 2010 The Society for Applied Microbiology.

  11. Rapid isolation of yeast genomic DNA: Bust n' Grab

    Directory of Open Access Journals (Sweden)

    Peterson Kenneth R

    2004-04-01

    Full Text Available Abstract Background Mutagenesis of yeast artificial chromosomes (YACs often requires analysis of large numbers of yeast clones to obtain correctly targeted mutants. Conventional ways to isolate yeast genomic DNA utilize either glass beads or enzymatic digestion to disrupt yeast cell wall. Using small glass beads is messy, whereas enzymatic digestion of the cells is expensive when many samples need to be analyzed. We sought to develop an easier and faster protocol than the existing methods for obtaining yeast genomic DNA from liquid cultures or colonies on plates. Results Repeated freeze-thawing of cells in a lysis buffer was used to disrupt the cells and release genomic DNA. Cell lysis was followed by extraction with chloroform and ethanol precipitation of DNA. Two hundred ng – 3 μg of genomic DNA could be isolated from a 1.5 ml overnight liquid culture or from a large colony. Samples were either resuspended directly in a restriction enzyme/RNase coctail mixture for Southern blot hybridization or used for several PCR reactions. We demonstrated the utility of this method by showing an analysis of yeast clones containing a mutagenized human β-globin locus YAC. Conclusion An efficient, inexpensive method for obtaining yeast genomic DNA from liquid cultures or directly from colonies was developed. This protocol circumvents the use of enzymes or glass beads, and therefore is cheaper and easier to perform when processing large numbers of samples.

  12. Yeast cell-based analysis of human lactate dehydrogenase isoforms.

    Science.gov (United States)

    Mohamed, Lulu Ahmed; Tachikawa, Hiroyuki; Gao, Xiao-Dong; Nakanishi, Hideki

    2015-12-01

    Human lactate dehydrogenase (LDH) has attracted attention as a potential target for cancer therapy and contraception. In this study, we reconstituted human lactic acid fermentation in Saccharomyces cerevisiae, with the goal of constructing a yeast cell-based LDH assay system. pdc null mutant yeast (mutated in the endogenous pyruvate decarboxylase genes) are unable to perform alcoholic fermentation; when grown in the presence of an electron transport chain inhibitor, pdc null strains exhibit a growth defect. We found that introduction of the human gene encoding LDHA complemented the pdc growth defect; this complementation depended on LDHA catalytic activity. Similarly, introduction of the human LDHC complemented the pdc growth defect, even though LDHC did not generate lactate at the levels seen with LDHA. In contrast, the human LDHB did not complement the yeast pdc null mutant, although LDHB did generate lactate in yeast cells. Expression of LDHB as a red fluorescent protein (RFP) fusion yielded blebs in yeast, whereas LDHA-RFP and LDHC-RFP fusion proteins exhibited cytosolic distribution. Thus, LDHB exhibits several unique features when expressed in yeast cells. Because yeast cells are amenable to genetic analysis and cell-based high-throughput screening, our pdc/LDH strains are expected to be of use for versatile analyses of human LDH. © The Authors 2015. Published by Oxford University Press on behalf of the Japanese Biochemical Society. All rights reserved.

  13. Yeast Biomass Production in Brewery's Spent Grains Hemicellulosic Hydrolyzate

    Science.gov (United States)

    Duarte, Luís C.; Carvalheiro, Florbela; Lopes, Sónia; Neves, Ines; Gírio, Francisco M.

    Yeast single-cell protein and yeast extract, in particular, are two products which have many feed, food, pharmaceutical, and biotechnological applications. However, many of these applications are limited by their market price. Specifically, the yeast extract requirements for culture media are one of the major technical hurdles to be overcome for the development of low-cost fermentation routes for several top value chemicals in a biorefinery framework. A potential biotechnical solution is the production of yeast biomass from the hemicellulosic fraction stream. The growth of three pentose-assimilating yeast cell factories, Debaryomyces hansenii, Kluyveromyces marxianus, and Pichia stipitis was compared using non-detoxified brewery's spent grains hemicellulosic hydrolyzate supplemented with mineral nutrients. The yeasts exhibited different specific growth rates, biomass productivities, and yields being D. hansenii as the yeast species that presented the best performance, assimilating all sugars and noteworthy consuming most of the hydrolyzate inhibitors. Under optimized conditions, D. hansenii displayed a maximum specific growth rate, biomass yield, and productivity of 0.34 h-1, 0.61 g g-1, and 0.56 g 1-1 h-1, respectively. The nutritional profile of D. hansenii was thoroughly evaluated, and it compares favorably to others reported in literature. It contains considerable amounts of some essential amino acids and a high ratio of unsaturated over saturated fatty acids.

  14. Unsuspected pyocyanin effect in yeast under anaerobiosis.

    Science.gov (United States)

    Barakat, Rana; Goubet, Isabelle; Manon, Stephen; Berges, Thierry; Rosenfeld, Eric

    2014-02-01

    The blue-green phenazine, Pyocyanin (PYO), is a well-known virulence factor produced by Pseudomonas aeruginosa, notably during cystic fibrosis lung infections. It is toxic to both eukaryotic and bacterial cells and several mechanisms, including the induction of oxidative stress, have been postulated. However, the mechanism of PYO toxicity under the physiological conditions of oxygen limitation that are encountered by P. aeruginosa and by target organisms in vivo remains unclear. In this study, wild-type and mutant strains of the yeast Saccharomyces cerevisiae were used as an effective eukaryotic model to determine the toxicity of PYO (100-500 μmol/L) under key growth conditions. Under respiro-fermentative conditions (with glucose as substrate), WT strains and certain H2 O2 -hypersensitive strains showed a low-toxic response to PYO. Under respiratory conditions (with glycerol as substrate) all the strains tested were significantly more sensitive to PYO. Four antioxidants were tested but only N-acetylcysteine was capable of partially counteracting PYO toxicity. PYO did not appear to affect short-term respiratory O2 uptake, but it did seem to interfere with cyanide-poisoned mitochondria through a complex III-dependent mechanism. Therefore, a combination of oxidative stress and respiration disturbance could partly explain aerobic PYO toxicity. Surprisingly, the toxic effects of PYO were more significant under anaerobic conditions. More pronounced effects were observed in several strains including a 'petite' strain lacking mitochondrial DNA, strains with increased or decreased levels of ABC transporters, and strains deficient in DNA damage repair. Therefore, even though PYO is toxic for actively respiring cells, O2 may indirectly protect the cells from the higher anaerobic-linked toxicity of PYO. The increased sensitivity to PYO under anaerobic conditions is not unique to S. cerevisiae and was also observed in another yeast, Candida albicans. © 2013 The Authors

  15. The yeast spectrum of the 'tea fungus Kombucha'.

    Science.gov (United States)

    Mayser, P; Fromme, S; Leitzmann, C; Gründer, K

    1995-01-01

    The tea fungus 'Kombucha' is a symbiosis of Acetobacter, including Acetobacter xylinum as a characteristic species, and various yeasts. A characteristic yeast species or genus has not yet been identified. Kombucha is mainly cultivated in sugared black tea to produce a slightly acidulous effervescent beverage that is said to have several curative effects. In addition to sugar, the beverage contains small amounts of alcohol and various acids, including acetic acid, gluconic acid and lactic acid, as well as some antibiotic substances. To characterize the yeast spectrum with special consideration given to facultatively pathogenic yeasts, two commercially available specimens of tea fungus and 32 from private households in Germany were analysed by micromorphological and biochemical methods. Yeasts of the genera Brettanomyces, Zygosaccharomyces and Saccharomyces were identified in 56%, 29% and 26% respectively. The species Saccharomycodes ludwigii and Candida kefyr were only demonstrated in isolated cases. Furthermore, the tests revealed pellicle-forming yeasts such as Candida krusei or Issatchenkia orientalis/occidentalis as well as species of the apiculatus yeasts (Kloeckera, Hanseniaspora). Thus, the genus Brettanomyces may be a typical group of yeasts that are especially adapted to the environment of the tea fungus. However, to investigate further the beneficial effects of tea fungus, a spectrum of the other typical genera must be defined. Only three specimens showed definite contaminations. In one case, no yeasts could be isolated because of massive contamination with Penicillium spp. In the remaining two samples (from one household), Candida albicans was demonstrated. The low rate of contamination might be explained by protective mechanisms, such as formation of organic acids and antibiotic substances. Thus, subjects with a healthy metabolism do not need to be advised against cultivating Kombucha. However, those suffering from immunosuppression should preferably

  16. Gut yeast communities in Larus michahellis from various breeding colonies.

    Science.gov (United States)

    Al-Yasiri, Mohammed Hashim; Normand, Anne-Cécile; Piarroux, Renaud; Ranque, Stéphane; Mauffrey, Jean-François

    2017-06-01

    Yellow-legged gulls have been reported to carry antibiotic-resistant Enterobacteriaceae; however, the gut mycobiota of these birds has not yet been described. In this study, we analyzed the gut yeast communities in five yellow-legged gull breeding colonies along the Mediterranean littoral in southern France. Gull fecal samples were inoculated onto four types of culture media, including one supplemented with itraconazole. Yeast species richness, abundance, and diversity were estimated, and factorial analysis was used to highlight correspondences between breeding colonies. Yeast grew in 113 of 177 cultures, and 17 distinct yeast species were identified. The most frequent species were Candida krusei (53.5%), Galactomyces geotrichum (44.1%), C. glabrata (40.9%), C. albicans (20.5%), and Saccharomyces cerevisiae (18.1%). Gut yeast community structure in the gulls at both Pierre-Blanche Lagoon (PB) and Frioul Archipelago (F) were characterized by greater species richness and diversity than in those at the two cities of La Grande-Motte (GM) and Palavas-les-Flots (PF) as well as Riou Archipelago (R). Gulls in these latter three sites probably share a similar type of anthropogenic diet. Notably, the proportion of anthropic yeast species, including C. albicans and C. glabrata, in the gull mycobiota increased with gull colony synanthropy. Antifungal resistance was found in each of the five most frequent yeast species. We found that the gut yeast communities of these yellow-legged gulls include antifungal-resistant human pathogens. Further studies should assess the public health impact of these common synanthropic seabirds, which represent a reservoir and disseminator of drug-resistant human pathogenic yeast into the environment. © The Author 2016. Published by Oxford University Press on behalf of The International Society for Human and Animal Mycology. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  17. Construction of gateway-compatible yeast two-hybrid vectors for ...

    African Journals Online (AJOL)

    Yeast two-hybrid system combined with the gateway technology will greatly facilitate the cloning of interested DNA fragment into yeast two-hybrid vectors and therefore increase the efficiency of yeast two-hybrid analysis. In this study, we constructed a pair of Gateway-compatible yeast two-hybrid vectors pBTM116GW and ...

  18. PMAA-stabilized ferrofluid/chitosan/yeast composite for bioapplications

    Science.gov (United States)

    Baldikova, Eva; Prochazkova, Jitka; Stepanek, Miroslav; Hajduova, Jana; Pospiskova, Kristyna; Safarikova, Mirka; Safarik, Ivo

    2017-04-01

    A simple, one-pot process for the preparation of magnetically responsive yeast-based biocatalysts was developed. Saccharomyces cerevisiae, Candida utilis and Kluyveromyces lactis cells were successfully incorporated into chitosan gel magnetically modified with poly(methacrylic acid)-stabilized magnetic fluid (PMAA-FF) during its formation. Magnetic PMAA-FF/chitosan/yeast composites were efficiently employed for invert sugar production. The dependence of invertase activity on used yeast, amount of magnetic biocatalyst, agitation time and after reuse was studied in detail. The tested magnetic biocatalysts retained at least 69% of their initial activity after 8 reuse cycles.

  19. Production of biopharmaceutical proteins by yeast: Advances through metabolic engineering

    DEFF Research Database (Denmark)

    Nielsen, Jens

    2013-01-01

    by yeast are human serum albumin, hepatitis vaccines and virus like particles used for vaccination against human papillomavirus. Here is given a brief overview of biopharmaceutical production by yeast and it is discussed how the secretory pathway can be engineered to ensure more efficient protein...... for production of several large volume products. Insulin and insulin analogs are by far the dominating biopharmaceuticals produced by yeast, and this will increase as the global insulin market is expected to grow from USD12B in 2011 to more than USD32B by 2018. Other important biopharmaceuticals produced...

  20. Yeasts isolated from clinical samples of AIDS patients

    Directory of Open Access Journals (Sweden)

    Neves Rejane Pereira

    2002-01-01

    Full Text Available In order to investigate yeasts in oropharyngeal secretion, urine, sputum and inguinal scales from AIDS patients, clinical samples were collected from one hundred patients interned in the Infectious and Parasitic Diseases Sector of the Hospital das Clínicas of the Universidade Federal de Pernambuco and in Hospital Universitário Osvaldo Cruz of the Universidade de Pernambuco. Yeasts were isolated from seventy-two out of one hundred and eight clinical samples. The isolated yeasts were: Candida albicans (sixty-two isolates, Candida tropicalis (four isolates, Candida glabrata (two isolates, Candida parapsilosis (two isolates, Candida krusei (one isolate and Trichosporon pullulans (one isolate.

  1. The Influence of Yeast Concentration in Fermentation of Beer

    OpenAIRE

    , K Pehlivani; , D Prifti

    2014-01-01

    Different factors play their role in the fermentation of beer but very important ones are temperature, C02 pressure and yeast concentration. In this work it has been studied the inşuence of the yeast concentration in the main parameters of fermentation. It has been studied the beer fermentation in three cases, with three different concentrations of yeast: First case was used the 20.0 X 106 cells/ml; Second case was used 22.0 X 106 cells/m1; Third case was used 24.0 X 10 6 cells/ml. All other ...

  2. Evolutionary biology through the lens of budding yeast comparative genomics.

    Science.gov (United States)

    Marsit, Souhir; Leducq, Jean-Baptiste; Durand, Éléonore; Marchant, Axelle; Filteau, Marie; Landry, Christian R

    2017-10-01

    The budding yeast Saccharomyces cerevisiae is a highly advanced model system for studying genetics, cell biology and systems biology. Over the past decade, the application of high-throughput sequencing technologies to this species has contributed to this yeast also becoming an important model for evolutionary genomics. Indeed, comparative genomic analyses of laboratory, wild and domesticated yeast populations are providing unprecedented detail about many of the processes that govern evolution, including long-term processes, such as reproductive isolation and speciation, and short-term processes, such as adaptation to natural and domestication-related environments.

  3. Production of yeast extract from whey using Kluyveromyces marxianus

    Directory of Open Access Journals (Sweden)

    Revillion Jean P. de Palma

    2003-01-01

    Full Text Available The yeast Kluyveromyces marxianus CBS 6556 was grown on whey to produce nucleotide-rich yeast extracts. Thermal treatments of cells at 35 or 50ºC for 15-30h resulted in yeast extracts containing about 20 g/L protein, with only the second treatment resulting in the presence of small amounts of RNA. In contrast, autolysis in buffered solution was the unique treatment that resulted in release of high amounts of intracellular RNA, being, therefore, the better procedure to produce 5'-nucletide rich extract with K. marxianus.

  4. Yeast biotechnology: teaching the old dog new tricks

    Science.gov (United States)

    2014-01-01

    Yeasts are regarded as the first microorganisms used by humans to process food and alcoholic beverages. The technology developed out of these ancient processes has been the basis for modern industrial biotechnology. Yeast biotechnology has gained great interest again in the last decades. Joining the potentials of genomics, metabolic engineering, systems and synthetic biology enables the production of numerous valuable products of primary and secondary metabolism, technical enzymes and biopharmaceutical proteins. An overview of emerging and established substrates and products of yeast biotechnology is provided and discussed in the light of the recent literature. PMID:24602262

  5. Industrial Relevance of Chromosomal Copy Number Variation in Saccharomyces Yeasts

    Science.gov (United States)

    Gorter de Vries, Arthur R.; Pronk, Jack T.

    2017-01-01

    ABSTRACT Chromosomal copy number variation (CCNV) plays a key role in evolution and health of eukaryotes. The unicellular yeast Saccharomyces cerevisiae is an important model for studying the generation, physiological impact, and evolutionary significance of CCNV. Fundamental studies of this yeast have contributed to an extensive set of methods for analyzing and introducing CCNV. Moreover, these studies provided insight into the balance between negative and positive impacts of CCNV in evolutionary contexts. A growing body of evidence indicates that CCNV not only frequently occurs in industrial strains of Saccharomyces yeasts but also is a key contributor to the diversity of industrially relevant traits. This notion is further supported by the frequent involvement of CCNV in industrially relevant traits acquired during evolutionary engineering. This review describes recent developments in genome sequencing and genome editing techniques and discusses how these offer opportunities to unravel contributions of CCNV in industrial Saccharomyces strains as well as to rationally engineer yeast chromosomal copy numbers and karyotypes. PMID:28341679

  6. Yeast peroxisomes : function and biogenesis of a versatile cell organelle

    NARCIS (Netherlands)

    van der Klei, IJ; Veenhuis, M

    1997-01-01

    Yeast peroxisomes harbour enzymes involved in the metabolism of specific growth substrates, Sequestration of these enzymes increases the efficiency of such pathways. Currently, 16 genes involved in peroxisome biogenesis have been identified, and analysis of their products suggests novel mechanisms

  7. Metabolic engineering of yeast for fermentative production of flavonoids

    DEFF Research Database (Denmark)

    Rodriguez Prado, Edith Angelica; Strucko, Tomas; Stahlhut, Steen Gustav

    2017-01-01

    Yeast Saccharomyces cerevisiae was engineered for de novo production of six different flavonoids (naringenin, liquiritigenin, kaempferol, resokaempferol, quercetin, and fisetin) directly from glucose, without supplementation of expensive intermediates. This required reconstruction of long...

  8. Black yeast-like fungi in skin and nail

    DEFF Research Database (Denmark)

    Saunte, D M; Tarazooie, B; Arendrup, M C

    2011-01-01

    Black yeast-like fungi are rarely reported from superficial infections. We noticed a consistent prevalence of these organisms as single isolations from mycological routine specimens. To investigate the prevalence of black yeast-like fungi in skin, hair and nail specimens and to discuss the probab......Black yeast-like fungi are rarely reported from superficial infections. We noticed a consistent prevalence of these organisms as single isolations from mycological routine specimens. To investigate the prevalence of black yeast-like fungi in skin, hair and nail specimens and to discuss...... prevalent species were Phialophora europaea (n = 29), Coniosporium epidermidis (n = 12), Ochroconis cf. humicola (n = 6) and Cladophialophora boppii (n = 4). These are not common saprobes and thus less likely to be coincidental colonizers. In 10/30 cases, discolouration of nail/skin had been noticed...

  9. Bioprospecting of yeasts for amylase production in solid state ...

    African Journals Online (AJOL)

    Bioprospecting of yeasts for amylase production in solid state fermentation and evaluation of the catalytic properties of enzymatic extracts. APA de Oliveira, MA Silvestre, HF Alves-Prado, A Rodrigues, MF da Paz, GG Fonseca, RSR Leite ...

  10. A contribution to the knowledge of yeasts in Olsztyn lakes

    Directory of Open Access Journals (Sweden)

    Maria Dynowska

    2014-08-01

    Full Text Available Yeasts species have been analysed from Skanda and Kartowo Lakes. Their presence reflects poor sanitary stale of the lakes, with Skanda Lake particulary affected by the process of eutrophication.

  11. Tools for genetic engineering of the yeast Hansenula polymorpha

    NARCIS (Netherlands)

    Saraya, Ruchi; Gidijala, Loknath; Veenhuis, Marten; van der Klei, Ida J; Mapelli, Valeria

    2014-01-01

    Hansenula polymorpha is a methylotrophic yeast species that has favorable properties for heterologous protein production and metabolic engineering. It provides an attractive expression platform with the capability to secrete high levels of commercially important proteins. Over the past few years

  12. Conversion of homothallic yeast to heterothallism through to gene disruption

    CSIR Research Space (South Africa)

    Van Zyl, WH

    1993-04-01

    Full Text Available A simple method was developed for the conversion of homothallic Saccharomyces cerevisiae yeast strains to heterothallism through HO gene disruption. An integrative ho=neo disrupted allele was constructed by cloning a dominant selectable marker...

  13. production of bioethanol from rice straw using yeast extracts ...

    African Journals Online (AJOL)

    user

    %(w/v), 2%(w/v) and 2.5%(w/v) concentrations as cells for ... Keywords: Bioethanol, Oryza sativa, Saccharomyces cerevisiae, Fermentation, Yield, Substrate. 1. INTRODUCTION .... Yeast Peptone Dextrose Agar (YPDA) medium. Plates.

  14. Molecular display technology using yeast--arming technology.

    Science.gov (United States)

    Shibasaki, Seiji; Maeda, Hatsuo; Ueda, Mitsuyoshi

    2009-01-01

    A technology to display proteins or peptides on living organisms has been developed over the last two decades. So-called "Molecular display (Arming) technology" or "Cell surface engineering" has been one of the important tools for analyzing and understanding protein function, or for screening of novel clones from libraries. In addition, it endows cells with novel abilities that cannot be added by conventional genetic recombination. In particular, the yeast Saccharomyces cerevisiae has a lot of advantages in molecular display technology. Normal yeast cells can be transformed into a wide variety of "arming yeasts" that have catalytic functions, affinity binding to valuable ligands, bioremediation properties, bio-monitoring properties, etc. This review describes the background, applications, and representative achievements of molecular display technology of yeast.

  15. Oxidative Stress and Programmed Cell Death in Yeast

    Science.gov (United States)

    Farrugia, Gianluca; Balzan, Rena

    2012-01-01

    Yeasts, such as Saccharomyces cerevisiae, have long served as useful models for the study of oxidative stress, an event associated with cell death and severe human pathologies. This review will discuss oxidative stress in yeast, in terms of sources of reactive oxygen species (ROS), their molecular targets, and the metabolic responses elicited by cellular ROS accumulation. Responses of yeast to accumulated ROS include upregulation of antioxidants mediated by complex transcriptional changes, activation of pro-survival pathways such as mitophagy, and programmed cell death (PCD) which, apart from apoptosis, includes pathways such as autophagy and necrosis, a form of cell death long considered accidental and uncoordinated. The role of ROS in yeast aging will also be discussed. PMID:22737670

  16. RAPD analysis : a rapid technique for differentation of spoilage yeasts

    NARCIS (Netherlands)

    Baleiras Couto, M.M.; Vossen, J.M.B.M. van der; Hofstra, H.; Huis in 't Veld, J.H.J.

    1994-01-01

    Techniques for the identification of the spoilage yeasts Saccharomyces cerevisiae and members of the Zygosaccharomyces genus from food and beverages sources were evaluated. The use of identification systems based on physiological characteristics resulted often in incomplete identification or

  17. The role of mitochondria in yeast programmed cell death

    Directory of Open Access Journals (Sweden)

    Nicoletta eGuaragnella

    2012-07-01

    Full Text Available Mammalian apoptosis and yeast programmed cell death (PCD share a variety of features including ROS production, protease activity and a major role played by mitochondria. In view of this, and of the distinctive characteristics differentiating yeast and multicellular organism PCD, the mitochondrial contribution to cell death in the genetically tractable yeast Saccharomyces cerevisiae has been intensively investigated. In this mini-review we report whether and how yeast mitochondrial function and proteins belonging to oxidative phosphorylation, protein trafficking into and out of mitochondria, and mitochondrial dynamics, play a role in PCD. Since in PCD many processes take place over time, emphasis will be placed on an experimental model based on acetic acid induced PCD (AA-PCD which has the unique feature of having been investigated as a function of time. As will be described there are at least two AA-PCD pathways each with a multifaceted role played by mitochondrial components, in particular by cytochrome c.

  18. Quantitative phosphoproteomics applied to the yeast pheromone signaling pathway

    DEFF Research Database (Denmark)

    Gruhler, Albrecht; Olsen, Jesper Velgaard; Mohammed, Shabaz

    2005-01-01

    /MS/MS) for identification. This integrated phosphoproteomic technology identified and quantified phosphorylation in key regulator and effector proteins of a prototypical G-protein-coupled receptor signaling pathway, the yeast pheromone response. SILAC encoding of yeast proteomes was achieved by incorporation of [(13)C(6......)]arginine and [(13)C(6)]lysine in a double auxotroph yeast strain. Pheromone-treated yeast cells were mixed with SILAC-encoded cells as the control and lysed, and extracted proteins were digested with trypsin. Phosphopeptides were enriched by a combination of strong cation exchange chromatography and IMAC...... phosphopeptides, 139 were differentially regulated at least 2-fold in response to mating pheromone. Among these regulated proteins were components belonging to the mitogen-activated protein kinase signaling pathway and to downstream processes including transcriptional regulation, the establishment of polarized...

  19. Localization of indigenous yeast in the murine stomach.

    Science.gov (United States)

    Savage, D C; Dubos, R J

    1967-12-01

    Certain strains of yeast were cultured frequently from the feces of adult CFW mice and Long-Evans and Sprague-Dawley rats, but not from infants of those murine strains, or from adults or infants of NCS or NCS-D mice. When the yeasts could be cultured from the feces, they could also be grown from all areas of the digestive tracts of the animals, but especially from the stomachs, where they formed layers on the epithelium of the glandular mucosa. Three of the yeast isolates, one each from the three murine colonies, were provisionally classified in the genus Torulopsis of the asporogenous yeasts. These yeast strains failed to colonize the digestive tubes of suckling infant mice of either the CFW or NCS-D colonies. In contrast, they colonized the guts of adult NCS-D mice and formed layers in their stomachs; tests with the yeast from CFW mice revealed that this strain colonized the guts and formed layers in the stomachs of germ-free CFW mice. When established in NCS-D mice, the yeast strains did not affect qualitatively or quantitatively the growth of the animals or the composition of the bacterial flora in the gastrointestinal tracts. Moreover, they did not elicit an unusual inflammatory response in the digestive tracts; nor were they pathogenic for NCS mice when injected by the intraperitoneal or intravenous routes. The yeasts thus appear to be harmless saprophytes that are able to flourish in the environment of the surface of the secreting epithelium of the murine stomach. The findings conform with the view that some types of microorganisms of the gastrointestinal tract are not just mixed randomly but rather occupy microenvironments in almost pure culture. This concept is important to the understanding of the ecology of the gut microflora.

  20. Yeast Diversity and Persistence in Botrytis-Affected Wine Fermentations

    OpenAIRE

    Mills, David A; Johannsen, Eric A.; Cocolin, Luca

    2002-01-01

    Culture-dependent and -independent methods were used to examine the yeast diversity present in botrytis-affected (“botrytized”) wine fermentations carried out at high (∼30°C) and ambient (∼20°C) temperatures. Fermentations at both temperatures possessed similar populations of Saccharomyces, Hanseniaspora, Pichia, Metschnikowia, Kluyveromyces, and Candida species. However, higher populations of non-Saccharomyces yeasts persisted in ambient-temperature fermentations, with Candida and, to a less...

  1. Bacterial and yeast counts in Brazilian commodities and spices

    Directory of Open Access Journals (Sweden)

    Freire Francisco das Chagas Oliveira

    2002-01-01

    Full Text Available A total of thirteen genera of bacteria and two genera of yeasts were detected in surface sterilized and unsterilized Brazilian commodities and spices such as cashew kernels, Brazil nut kernels, black and white pepper. The genus Bacillus with eight species was by far the most common. The yeasts isolated were Pichia sp., P. guillermondii and Rhodotorula sp. Bacillus cereus, Salmonella typhimurium and Staphylococcus aureus were detected in cashew and Brazil nut kernels.

  2. A review on sustainable yeast biotechnological processes and applications

    DEFF Research Database (Denmark)

    Nandy, Subir Kumar; Srivastava, R. K.

    2018-01-01

    Yeast is very well known eukaryotic organism for its remarkable biodiversity and extensive industrial applications. Saccharomyces cerevisiae is one of the most widely used microorganisms in biotechnology with successful applications in the biochemical production. Biological conversion with the fo......Yeast is very well known eukaryotic organism for its remarkable biodiversity and extensive industrial applications. Saccharomyces cerevisiae is one of the most widely used microorganisms in biotechnology with successful applications in the biochemical production. Biological conversion...

  3. Antimicrobial activity of yeasts against some pathogenic bacteria

    OpenAIRE

    Gamal Younis; Amal Awad; Dawod, Rehab E.; Yousef, Nehal E.

    2017-01-01

    Aim: This study was designed to isolate and identify yeast species from milk and meat products, and to test their antimicrobial activity against some bacterial species. Materials and Methods: A total of 160 milk and meat products samples were collected from random sellers and super markets in New Damietta city, Damietta, Egypt. Samples were subjected to yeast isolation procedures and tested for its antimicrobial activity against Staphylococcus aureus, Pseudomonas aeruginosa, and Escherich...

  4. Isolation of yeast Saccharomyces cerevisiae from unusual natural habitats

    OpenAIRE

    Finžgar, Bernarda

    2012-01-01

    Baker yeast Saccharomyces cerevisiae has been an eukarontic experimental organism since 1960s, becoming even more significant with the determination of its complete nucleotide genome sequence in 1996. Even though its biochemical function in the fermentation process had long remained unclear, its metabolism and products (eg. bread, beer, wine) have been used for millennia. S. cerevisiae yeast represents an important organism for production of recombinant proteins (gene manipulation). Moreover,...

  5. Spent yeast as natural source of functional food additives

    Science.gov (United States)

    Rakowska, Rita; Sadowska, Anna; Dybkowska, Ewa; Świderski, Franciszek

    Spent yeasts are by-products arising from beer and wine production which over many years have been chiefly used as feed additives for livestock. They contain many valuable and bioactive substances which has thereby generated much interest in their exploitation. Up till now, the main products obtained from beer-brewing yeasts are β-glucans and yeast extracts. Other like foodstuffs include dried brewer’s yeast, where this is dried and the bitterness removed to be fit for human consumption as well as mannan-oligosaccharides hitherto used in the feed industry. β-glucans constitute the building blocks of yeast cell walls and can thus be used in human nutrition as dietary supplements or serving as food additives in functional foods. β-glucans products obtained via post-fermentation of beer also exhibit a high and multi-faceted biological activity where they improve the blood’s lipid profile, enhance immunological status and have both prebiotic and anti-oxidant properties. Yeast extracts are currently being used more and more to enhance flavour in foodstuffs, particularly for meat and its products. Depending on how autolysis is carried out, it is possible to design extracts of various meat flavours characteristic of specific meats. Many different flavour profiles can be created which may be additionally increased in combination with vegetable extracts. Within the food market, yeast extracts can appear in various guises such as liquids, pastes or powders. They all contain significant amounts of glutamic acid, 5’-GMP and 5’-IMP nucleotides together with various amino acids and peptides that act synergistically for enhancing the flavour of foodstuff products. Recent studies have demonstrated additional benefits of yeast extracts as valuable sources of amino acids and peptides which can be used in functional foods and dietary supplements. These products possess GRAS status (Generally Recognised As Safe) which thereby also adds further as to why they should be used

  6. Comparative genomics: a revolutionary tool for wine yeast strain development.

    Science.gov (United States)

    Borneman, Anthony R; Pretorius, Isak S; Chambers, Paul J

    2013-04-01

    The application of Next Generation sequencing to comparative genomics is enabling in-depth characterization of genetic variation between wine yeast strains used in fermentation starter cultures. Knowledge from this work will be harnessed in strain development programs. As a result, winemakers will soon have at their disposal novel, improved yeast starter cultures displaying increased reliability and providing a means of tailoring wine sensory characteristics for new and ever-changing markets. Copyright © 2012 Elsevier Ltd. All rights reserved.

  7. Yeasts and wine off-flavours: a technological perspective

    OpenAIRE

    Malfeito-Ferreira, Manuel

    2010-01-01

    Review article. Part of the special issue "Wine microbiology and safety: from the vineyard to the bottle (Microsafety Wine)", 19-20 Nov. 2009, Italy In wine production, yeasts have both beneficial and detrimental activities. Saccharomyces cerevisiae is the yeast mainly responsible for turning grape juice into wine but this species and several others may also show undesirable effects in wines. Among such effects, technologists are particularly concerned with the production of...

  8. Quantitative Analysis of the Effective Functional Structure in Yeast Glycolysis

    OpenAIRE

    Cortes, Jesus M.; Ildefonso M. De la Fuente

    2010-01-01

    Yeast glycolysis is considered the prototype of dissipative biochemical oscillators. In cellular conditions, under sinusoidal source of glucose, the activity of glycolytic enzymes can display either periodic, quasiperiodic or chaotic behavior. In order to quantify the functional connectivity for the glycolytic enzymes in dissipative conditions we have analyzed different catalytic patterns using the non-linear statistical tool of Transfer Entropy. The data were obtained by means of a yeast gly...

  9. Digestibilidade da dieta, parâmetros ruminais e desempenho de ovinos Santa Inês alimentados com polpa cítrica peletizada e resíduo úmido de cervejaria Diet digestibility, ruminal parameters and performance of Santa Ines sheep fed dried citrus pulp and wet brewer grain

    Directory of Open Access Journals (Sweden)

    Susana Gilaverte

    2011-03-01

    Full Text Available Dois experimentos foram realizados com o objetivo de avaliar o efeito da substituição do milho por polpa cítrica peletizada e resíduo úmido de cervejaria sobre a digestibilidade aparente dos nutrientes da dieta, os parâmetros ruminais e o desempenho de ovinos. As dietas foram definidas pela substituição do milho (controle pela polpa cítrica peletizada ou pela mistura de resíduo úmido de cervejaria e polpa cítrica. No experimento 1, para avaliação do consumo, da digestibilidade aparente dos nutrientes e dos parâmetros ruminais, foram utilizados 12 machos da raça Santa Inês canulados no rúmen, distribuídos em delineamento experimental de blocos completos casualisados, com três dietas e quatro repetições. No experimento 2, para avaliação do desempenho, foram confinadas 48 fêmeas, que foram alimentadas com as mesmas dietas do experimento 1. A substituição do milho pela polpa cítrica peletizada não influenciou o consumo nem a digestibilidade dos nutrientes da dieta, diferente da inclusão de resíduo úmido de cervejaria, que reduziu o consumo e a digestibilidade aparente dos nutrientes, com exceção apenas da FDN, cuja digestibilidade aparente foi similar entre as dietas. A inclusão de resíduo úmido de cervejaria na dieta reduziu as concentrações ruminais de acetato e propionato e aumentou a relação acetato/propionato e o pH ruminal. Em geral, não há diferença entre a dieta contendo milho e aquela contendo polpa cítrica em substituição total ao milho. A utilização de resíduo úmido de cervejaria, no entanto, reduz o ganho médio diário, o peso corporal final e a eficiência alimentar.Two experiments were carried out with the objective to determine the effect of replacing corn by dried citrus pulp and wet brewer grain on apparent digestibility of nutrients of the diet, ruminal parameters and performance of sheep. The diets were defined by the replacement of corn (control by dried citrus pulp or by a

  10. Chimeric types of chromosome X in bottom-fermenting yeasts.

    Science.gov (United States)

    Ogata, T; Izumikawa, M; Tadami, H

    2009-10-01

    To determine the structure of the chimeric chromosome X of bottom-fermenting yeasts. Eight cosmid clones carrying DNA from chromosome X of bottom-fermenting yeasts were selected by end-sequencing. Four of the cosmid clones had Saccharomyces cerevisiae (SC)-type and Saccharomyces bayanus (SB)-type chimeric ends, two had SC-type ends and two had SB-type ends. Sequencing revealed that the bottom-fermenting yeast strains in this study had four types of chromosome X: SC-SC, SC-SB, SB-SC and SB-SB. The translocation site in the chimeric chromosome is conserved among bottom-fermenting yeast strains, and was created by homologous recombination within a region of high sequence identity between the SC-type sequence and the SB-type sequence. Existing bottom-fermenting yeast strains share a common ancestor in which the chimeric chromosome X was generated. The knowledge gained in this study sheds light on the evolution of bottom-fermenting yeasts.

  11. Yeast-suspension as soiling matter in disinfectant testing.

    Science.gov (United States)

    Løberg, R M; Faegri, A; Hegna, I K

    1989-01-01

    Using the Kelsey-Sykes capacity-test, it was found that a sterile yeast suspension used to simulate 'dirty' conditions, gave an increased effect of Chloramine T against the fungi Candida albicans, Aspergillus fumigatus, Geotrichum candidum and Penicillium sp. compared with the effect under 'clean' conditions. This effect was not found with the fungus Rhodotorula rubra nor on the various bacteria tested. The enhanced effect was found with respect to both Chloramine T and Chloramine B, but not with the sodium hypochlorite solution when tested on C. albicans. This effect was due to a diffusible factor from the yeast cells. The factor was evident in the solution after heating of the yeast-cell suspension and in unsterilized yeast-cell suspension left at room temperature for 2 h or more. The effect of Chloramine T on the fungi C. albicans and A. fumigatus was reduced as expected when the yeast suspension was replaced by 20% normal horse serum. The results indicate that using sterile yeast suspensions in this type of test, may erroneously give high fungicidal effects of Chloramine, and thus lead to an incorrect use-dilution concentration, especially if the determination is made on the basis of the effect observed only under dirty conditions.

  12. Association between Grape Yeast Communities and the Vineyard Ecosystems.

    Directory of Open Access Journals (Sweden)

    João Drumonde-Neves

    Full Text Available The grape yeast biota from several wine-producing areas, with distinct soil types and grapevine training systems, was assessed on five islands of Azores Archipelago, and differences in yeast communities composition associated with the geographic origin of the grapes were explored. Fifty-seven grape samples belonging to the Vitis vinifera grapevine cultivars Verdelho dos Açores (Verdelho, Arinto da Terceira (Arinto and Terrantez do Pico (Terrantez were collected in two consecutive years and 40 spontaneous fermentations were achieved. A total of 1710 yeast isolates were obtained from freshly crushed grapes and 1200 from final stage of fermentations. Twenty-eight species were identified, Hanseniaspura uvarum, Pichia terricola and Metschnikowia pulcherrima being the three most representative species isolated. Candida carpophila was encountered for the first time as an inhabitant of grape or wine-associated environments. In both sampling years, a higher proportion of H. uvarum in fresh grapes from Verdelho cultivar was observed, in comparison with Arinto cultivar. Qualitatively significant differences were found among yeast communities from several locations on five islands of the Archipelago, particularly in locations with distinctive agro-ecological compositions. Our results are in agreement with the statement that grape-associated microbial biogeography is non-randomly associated with interactions of climate, soil, cultivar, and vine training systems in vineyard ecosystems. Our observations strongly support a possible linkage between grape yeast and wine typicality, reinforcing the statement that different viticultural terroirs harbor distinctive yeast biota, in particular in vineyards with very distinctive environmental conditions.

  13. Association between Grape Yeast Communities and the Vineyard Ecosystems.

    Science.gov (United States)

    Drumonde-Neves, João; Franco-Duarte, Ricardo; Lima, Teresa; Schuller, Dorit; Pais, Célia

    2017-01-01

    The grape yeast biota from several wine-producing areas, with distinct soil types and grapevine training systems, was assessed on five islands of Azores Archipelago, and differences in yeast communities composition associated with the geographic origin of the grapes were explored. Fifty-seven grape samples belonging to the Vitis vinifera grapevine cultivars Verdelho dos Açores (Verdelho), Arinto da Terceira (Arinto) and Terrantez do Pico (Terrantez) were collected in two consecutive years and 40 spontaneous fermentations were achieved. A total of 1710 yeast isolates were obtained from freshly crushed grapes and 1200 from final stage of fermentations. Twenty-eight species were identified, Hanseniaspura uvarum, Pichia terricola and Metschnikowia pulcherrima being the three most representative species isolated. Candida carpophila was encountered for the first time as an inhabitant of grape or wine-associated environments. In both sampling years, a higher proportion of H. uvarum in fresh grapes from Verdelho cultivar was observed, in comparison with Arinto cultivar. Qualitatively significant differences were found among yeast communities from several locations on five islands of the Archipelago, particularly in locations with distinctive agro-ecological compositions. Our results are in agreement with the statement that grape-associated microbial biogeography is non-randomly associated with interactions of climate, soil, cultivar, and vine training systems in vineyard ecosystems. Our observations strongly support a possible linkage between grape yeast and wine typicality, reinforcing the statement that different viticultural terroirs harbor distinctive yeast biota, in particular in vineyards with very distinctive environmental conditions.

  14. Optimization of killer assays for yeast selection protocols.

    Science.gov (United States)

    Lopes, C A; Sangorrín, M P

    2010-01-01

    A new optimized semiquantitative yeast killer assay is reported for the first time. The killer activity of 36 yeast isolates belonging to three species, namely, Metschnikowia pulcherrima, Wickerhamomyces anomala and Torulaspora delbrueckii, was tested with a view to potentially using these yeasts as biocontrol agents against the wine spoilage species Pichia guilliermondii and Pichia membranifaciens. The effectiveness of the classical streak-based (qualitative method) and the new semiquantitative techniques was compared. The percentage of yeasts showing killer activity was found to be higher by the semiquantitative technique (60%) than by the qualitative method (45%). In all cases, the addition of 1% NaCl into the medium allowed a better observation of the killer phenomenon. Important differences were observed in the killer capacity of different isolates belonging to a same killer species. The broadest spectrum of action was detected in isolates of W. anomala NPCC 1023 and 1025, and M. pulcherrima NPCC 1009 and 1013. We also brought experimental evidence supporting the importance of the adequate selection of the sensitive isolate to be used in killer evaluation. The new semiquantitative method proposed in this work enables to visualize the relationship between the number of yeasts tested and the growth of the inhibition halo (specific productivity). Hence, this experimental approach could become an interesting tool to be taken into account for killer yeast selection protocols.

  15. Yeast signaling pathways in the oxidative stress response

    Energy Technology Data Exchange (ETDEWEB)

    Ikner, Aminah [Section of Microbiology, Division of Biological Sciences, University of California, Davis, CA 95616 (United States); Shiozaki, Kazuhiro [Section of Microbiology, Division of Biological Sciences, University of California, Davis, CA 95616 (United States)]. E-mail: kshiozaki@ucdavis.edu

    2005-01-06

    Oxidative stress that generates the reactive oxygen species (ROS) is one of the major causes of DNA damage and mutations. The 'DNA damage checkpoint' that arrests cell cycle and repairs damaged DNA has been a focus of recent studies, and the genetically amenable model systems provided by yeasts have been playing a leading role in the eukaryotic checkpoint research. However, means to eliminate ROS are likely to be as important as the DNA repair mechanisms in order to suppress mutations in the chromosomal DNA, and yeasts also serve as excellent models to understand how eukaryotes combat oxidative stress. In this article, we present an overview of the signaling pathways that sense oxidative stress and induce expression of various anti-oxidant genes in the budding yeast Saccharomyces cerevisiae, the fission yeast Schizosaccharomyces pombe and the pathogenic yeast Candida albicans. Three conserved signaling modules have been identified in the oxidative stress response of these diverse yeast species: the stress-responsive MAP kinase cascade, the multistep phosphorelay and the AP-1-like transcription factor. The structure and function of these signaling modules are discussed.

  16. Psychrophilic yeasts in glacial environments of Alpine glaciers.

    Science.gov (United States)

    Turchetti, Benedetta; Buzzini, Pietro; Goretti, Marta; Branda, Eva; Diolaiuti, Guglielmina; D'Agata, Carlo; Smiraglia, Claudio; Vaughan-Martini, Ann

    2008-01-01

    The presence of psychrophilic yeasts in supra- and subglacial sediments, ice and meltwater collected from two glaciers of the Italian Alps (Forni and Sforzellina-Ortles-Cevedale group) was investigated. After incubation at 4 degrees C, subglacial sediments contained from 1.3 x 10(3) to 9.6 x 10(3) CFU of yeasts g(-1). The number of yeast cells in supraglacial sediments was c. 10-100-fold lower. A significant proportion of isolated yeasts exhibited one or more extracellular enzymatic activities (starch-degrading, lipolytic, esterolytic, proteolytic and pectinolytic activity) at 4 degrees C. Selected isolates were able to grow at 2 degrees C under laboratory-simulated in situ conditions. In all, 106 isolated yeasts were identified by MSP-PCR fingerprinting and 26S rRNA gene sequencing of the D1/D2 region as belonging to 10 species: Aureobasidium pullulans, Cryptococcus gilvescens (over 50% of the total), Cryptococcus terricolus, Mrakia gelida, Naganishia globosa, Rhodotorula glacialis, Rhodotorula psychrophenolica, Rhodotorula bacarum, Rhodotorula creatinivora and Rhodotorula laryngis. Four strains, all belonging to a new yeast species, yet to be described, were also isolated.

  17. Yeast genome sequencing: the power of comparative genomics.

    Science.gov (United States)

    Piskur, Jure; Langkjaer, Rikke B

    2004-07-01

    For decades, unicellular yeasts have been general models to help understand the eukaryotic cell and also our own biology. Recently, over a dozen yeast genomes have been sequenced, providing the basis to resolve several complex biological questions. Analysis of the novel sequence data has shown that the minimum number of genes from each species that need to be compared to produce a reliable phylogeny is about 20. Yeast has also become an attractive model to study speciation in eukaryotes, especially to understand molecular mechanisms behind the establishment of reproductive isolation. Comparison of closely related species helps in gene annotation and to answer how many genes there really are within the genomes. Analysis of non-coding regions among closely related species has provided an example of how to determine novel gene regulatory sequences, which were previously difficult to analyse because they are short and degenerate and occupy different positions. Comparative genomics helps to understand the origin of yeasts and points out crucial molecular events in yeast evolutionary history, such as whole-genome duplication and horizontal gene transfer(s). In addition, the accumulating sequence data provide the background to use more yeast species in model studies, to combat pathogens and for efficient manipulation of industrial strains.

  18. Auxanographic Carbohydrate Assimilation Method for Large Scale Yeast Identification.

    Science.gov (United States)

    Devadas, Suganthi Martena; Ballal, Mamatha; Prakash, Peralam Yegneswaran; Hande, Manjunath H; Bhat, Geetha V; Mohandas, Vinitha

    2017-04-01

    The auxanographic carbohydrate assimilation had been an important method for differentiation of yeasts. Prevailing methods described in the literature for carbohydrate assimilation has limited scope for use in large scale yeast identification. To optimize the large scale auxanographic carbohydrate assimilation method for yeast identification. A modified auxanographic carbohydrate assimilation method was developed and a total of 35 isolates of Candida species comprising of four ATCC (American Type Culture Collection) Candida strains ( Candida albicans ATCC 90028, Candida tropicalis ATCC 90018, Candida parapsilosis ATCC 750, Candida krusei ATCC 6258) and 31 clinical isolates of Candida tropicalis (n=13), Candida krusei (n=7), Candida glabrata (n=3), Candida kefyr (n=3), Candida albicans (n=5) were validated. The carbohydrates tested were Glucose, Sucrose, Maltose, Lactose, Cellubiose, Raffinose, Trehalose, Xylose, Galactose and Dulcitol. A total of 35 Candida species were tested for their carbohydrate assimilative property and the results were consistent with the existing standard protocols. A well circumscribed opaque yeast growth indicated assimilation of the test carbohydrate and translucent to opalescent growth with the outline of initial inoculum alone indicated lack of assimilation. The control plate indicated no growth of the Candida species. The carbohydrate assimilation tests finds utility for yeast diversity studies exploring novel ecological niches. The technique described here facilitates testing of an extended range of carbohydrates and yeasts in a cost effective manner.

  19. The Fermentative and Aromatic Ability of Kloeckera and Hanseniaspora Yeasts

    Science.gov (United States)

    Díaz-Montaño, Dulce M.; de Jesús Ramírez Córdova, J.

    Spontaneous alcoholic fermentation from grape, agave and others musts into an alcoholic beverage is usually characterized by the presence of several non-Saccharomyces yeasts. These genera yeasts are dominant in the early stages of the alcoholic fermentation. However the genera Hanseniaspora and Kloeckera may survive at a significant level during fermentation and can influence the chemical composition of the beverage. Several strains belonging to the species Kloeckera api-culata and Hanseniaspora guilliermondii have been extensively studied in relation to the formation of some metabolic compounds affecting the bouquet of the final product. Indeed some apiculate yeast showed positive oenological properties and their use in the alcoholic fermentations has been suggested to enhance the aroma and flavor profiles. The non- Saccharomyces yeasts have the capability to produce and secrete enzymes in the medium, such as β -glucosidases, which release monoterpenes derived from their glycosylated form. These compounds contribute to the higher fruit-like characteristic of final product. This chapter reviews metabolic activity of Kloeckera and Hanseniaspora yeasts in several aspects: fermentative capability, aromatic compounds production and transformation of aromatic precursor present in the must, also covers the molecular methods for identifying of the yeast

  20. Guidelines and recommendations on yeast cell death nomenclature

    Directory of Open Access Journals (Sweden)

    Didac Carmona-Gutierrez

    2018-01-01

    Full Text Available Elucidating the biology of yeast in its full complexity has major implications for science, medicine and industry. One of the most critical processes determining yeast life and physiology is cellular demise. However, the investigation of yeast cell death is a relatively young field, and a widely accepted set of concepts and terms is still missing. Here, we propose unified criteria for the definition of accidental, regulated, and programmed forms of cell death in yeast based on a series of morphological and biochemical criteria. Specifically, we provide consensus guidelines on the differential definition of terms including apoptosis, regulated necrosis, and autophagic cell death, as we refer to additional cell death routines that are relevant for the biology of (at least some species of yeast. As this area of investigation advances rapidly, changes and extensions to this set of recommendations will be implemented in the years to come. Nonetheless, we strongly encourage the authors, reviewers and editors of scientific articles to adopt these collective standards in order to establish an accurate framework for yeast cell death research and, ultimately, to accelerate the progress of this vibrant field of research.

  1. Influence of yeast strain on Shiraz wine quality indicators.

    Science.gov (United States)

    Holt, Helen; Cozzolino, Daniel; McCarthy, Jane; Abrahamse, Caroline; Holt, Sylvester; Solomon, Mark; Smith, Paul; Chambers, Paul J; Curtin, Chris

    2013-08-01

    Wine styles are defined by complex and highly diverse chemical compositions. Evidence suggests that some of this complexity is determined by the choice of yeast strain used in fermentation. There are hundreds of different commercially available wine yeast strains that, potentially, provide a means by which winemakers can tailor their wines for different consumer market segments. In this study we evaluated the impacts of fermenting Shiraz must with different yeast strains, with a focus on chemical composition and tannin content of the finished wines. Principal Component Analysis (PCA) of the wines indicated that choice of yeast strain had a strong influence on a number of wine compositional parameters, including tannin. In three fermentation experiments, across two vintages and using different winemaking protocols, a compelling case for yeast strain 'signature' was evident. The results demonstrate that there is an opportunity to use commercial wine yeast diversity to modulate red wine composition and, by implication, the style of finished wines. Copyright © 2013 Elsevier B.V. All rights reserved.

  2. Yeast diversity on grapes in two German wine growing regions.

    Science.gov (United States)

    Brysch-Herzberg, Michael; Seidel, Martin

    2015-12-02

    The yeast diversity on wine grapes in Germany, one of the most northern wine growing regions of the world, was investigated by means of a culture dependent approach. All yeast isolates were identified by sequence analysis of the D1/D2 domain of the 26S rDNA and the ITS region. Besides Hanseniaspora uvarum and Metschnikowia pulcherrima, which are well known to be abundant on grapes, Metschnikowia viticola, Rhodosporidium babjevae, and Curvibasidium pallidicorallinum, as well as two potentially new species related to Sporidiobolus pararoseus and Filobasidium floriforme, turned out to be typical members of the grape yeast community. We found M. viticola in about half of the grape samples in high abundance. Our data strongly suggest that M. viticola is one of the most important fermenting yeast species on grapes in the temperate climate of Germany. The frequent occurrence of Cu. pallidicorallinum and strains related to F. floriforme is a new finding. The current investigation provides information on the distribution of recently described yeast species, some of which are known from a very few strains up to now. Interestingly yeasts known for their role in the wine making process, such as Saccharomyces cerevisiae, Saccharomyces bayanus ssp. uvarum, Torulaspora delbrueckii, and Zygosaccharomyces bailii, were not found in the grape samples. Copyright © 2015. Published by Elsevier B.V.

  3. Immobilisation increases yeast cells' resistance to dehydration-rehydration treatment.

    Science.gov (United States)

    Borovikova, Diana; Rozenfelde, Linda; Pavlovska, Ilona; Rapoport, Alexander

    2014-08-20

    This study was performed with the goal of revealing if the dehydration procedure used in our new immobilisation method noticeably decreases the viability of yeast cells in immobilised preparations. Various yeasts were used in this research: Saccharomyces cerevisiae cells that were rather sensitive to dehydration and had been aerobically grown in an ethanol-containing medium, a recombinant strain of S. cerevisiae grown in aerobic conditions which were completely non-resistant to dehydration and an anaerobically grown bakers' yeast strain S. cerevisiae, as well as a fairly resistant Pichia pastoris strain. Experiments performed showed that immobilisation of all these strains essentially increased their resistance to a dehydration-rehydration treatment. The increase of cells' viability (compared with control cells dehydrated in similar conditions) was from 30 to 60%. It is concluded that a new immobilisation method, which includes a dehydration stage, does not lead to an essential loss of yeast cell viability. Correspondingly, there is no risk of losing the biotechnological activities of immobilised preparations. The possibility of producing dry, active yeast preparations is shown, for those strains that are very sensitive to dehydration and which can be used in biotechnology in an immobilised form. Finally, the immobilisation approach can be used for the development of efficient methods for the storage of recombinant yeast strains. Copyright © 2014 Elsevier B.V. All rights reserved.

  4. Yeast diversity of sourdoughs and associated metabolic properties and functionalities.

    Science.gov (United States)

    De Vuyst, Luc; Harth, Henning; Van Kerrebroeck, Simon; Leroy, Frédéric

    2016-12-19

    Together with acidifying lactic acid bacteria, yeasts play a key role in the production process of sourdough, where they are either naturally present or added as a starter culture. Worldwide, a diversity of yeast species is encountered, with Saccharomyces cerevisiae, Candida humilis, Kazachstania exigua, Pichia kudriavzevii, Wickerhamomyces anomalus, and Torulaspora delbrueckii among the most common ones. Sourdough-adapted yeasts are able to withstand the stress conditions encountered during their growth, including nutrient starvation as well as the effects of acidic, oxidative, thermal, and osmotic stresses. From a technological point of view, their metabolism primarily contributes to the leavening and flavour of sourdough products. Besides ethanol and carbon dioxide, yeasts can produce metabolites that specifically affect flavour, such as organic acids, diacetyl, higher alcohols from branched-chain amino acids, and esters derived thereof. Additionally, several yeast strains possess functional properties that can potentially lead to nutritional and safety advantages. These properties encompass the production of vitamins, an improvement of the bioavailability of phenolic compounds, the dephosphorylation of phytic acid, the presence of probiotic potential, and the inhibition of fungi and their mycotoxin production. Strains of diverse species are new candidate functional starter cultures, offering opportunities beyond the conventional use of baker's yeast. Copyright © 2016 Elsevier B.V. All rights reserved.

  5. Prevalence of yeast other than Candida albicans in denture wearers.

    Science.gov (United States)

    Cavaleiro, Inês; Proença, Luis; Félix, Sérgio; Salema-Oom, Madalena

    2013-07-01

    The isolation of yeast species other than Candida albicans from the oral mucosa has been increasing in frequency, suggesting that those may constitute emerging potential oral colonizers. The purpose of this work was to determine whether yeast species other than C. albicans are associated with factors related to wearing of dental prostheses. tRNA-PCR fingerprinting and sequencing of the 26S rDNA D1/D2 domain were used to identify all yeasts isolated from CHROMagar™ Candida cultures of oral swabs collected from 178 patients. Besides C. albicans, 13 other species were identified, corresponding to 34% of the yeast isolates. The majority of the non-C. albicans species were not detected as single colonizers but rather in co-colonization with one or two other yeasts, often with C. albicans. No significant associations were found with non-C. albicans species. On the contrary, the best-fitted logistic regression model predicts that either wearing a denture (adjusted odds = 4.6) or insufficient oral hygiene (adjusted odds = 2.3) are risks for colonization by yeast, in general. The colonization with non-C. albicans species and co-colonization were not independently associated with any of the analyzed host-related factors. In particular, neither wearing a removable denture nor being elderly were significant predictors. © 2012 by the American College of Prosthodontists.

  6. Interactions between Drosophila and its natural yeast symbionts?Is Saccharomyces cerevisiae a good model for studying the fly-yeast relationship?

    OpenAIRE

    Hoang, Don; Kopp, Artyom; Chandler, James Angus

    2015-01-01

    Yeasts play an important role in the biology of the fruit fly, Drosophila melanogaster. In addition to being a valuable source of nutrition, yeasts affect D. melanogaster behavior and interact with the host immune system. Most experiments investigating the role of yeasts in D. melanogaster biology use the baker’s yeast, Saccharomyces cerevisiae. However, S. cerevisiae is rarely found with natural populations of D. melanogaster or other Drosophila species. Moreover, the strain of S. cerevisiae...

  7. In vitro antifungal activity of fluconazole and voriconazole against non-Candida yeasts and yeast-like fungi clinical isolates.

    Science.gov (United States)

    Mandras, Narcisa; Roana, Janira; Scalas, Daniela; Fucale, Giacomo; Allizond, Valeria; Banche, Giuliana; Barbui, Anna; Li Vigni, Nicolò; Newell, Vance A; Cuffini, Anna Maria; Tullio, Vivian

    2015-10-01

    The risk of opportunistic infections caused by non-Candida yeasts and yeast-like fungi is increasingly common, mainly in immunocompromised patients. Appropriate first-line therapy has not been defined and standardized, mainly due to the low number of cases reported. To improve empirical treatment guidelines, we describe the susceptibility profile to fluconazole and voriconazole of 176 non-Candida yeasts and yeast-like fungi collected from hospitals in Piedmont, North West Italy from January 2009 to December 2013. The results showed that most isolates are susceptible to voriconazole (94%), but less susceptible to fluconazole (78%), suggesting that voriconazole could be used as first-line therapy in infections caused by these fungi.

  8. Golgi maturation visualized in living yeast.

    Science.gov (United States)

    Losev, Eugene; Reinke, Catherine A; Jellen, Jennifer; Strongin, Daniel E; Bevis, Brooke J; Glick, Benjamin S

    2006-06-22

    The Golgi apparatus is composed of biochemically distinct early (cis, medial) and late (trans, TGN) cisternae. There is debate about the nature of these cisternae. The stable compartments model predicts that each cisterna is a long-lived structure that retains a characteristic set of Golgi-resident proteins. In this view, secretory cargo proteins are transported by vesicles from one cisterna to the next. The cisternal maturation model predicts that each cisterna is a transient structure that matures from early to late by acquiring and then losing specific Golgi-resident proteins. In this view, secretory cargo proteins traverse the Golgi by remaining within the maturing cisternae. Various observations have been interpreted as supporting one or the other mechanism. Here we provide a direct test of the two models using three-dimensional time-lapse fluorescence microscopy of the yeast Saccharomyces cerevisiae. This approach reveals that individual cisternae mature, and do so at a consistent rate. In parallel, we used pulse-chase analysis to measure the transport of two secretory cargo proteins. The rate of cisternal maturation matches the rate of protein transport through the secretory pathway, suggesting that cisternal maturation can account for the kinetics of secretory traffic.

  9. [Invasive yeast infections in severely burned patients].

    Science.gov (United States)

    Renau, Ana Isabel; García-Vidal, Carolina; Salavert, Miguel

    2016-01-01

    Currently, there are few studies on candidaemia in the severely burned patient. These patients share the same risk factors for invasive fungal infections as other critically ill patients, but have certain characteristics that make them particularly susceptible. These include the loss of skin barrier due to extensive burns, fungal colonisation of the latter, and the use of hydrotherapy or other topical therapies (occasionally with antimicrobials). In addition, the increased survival rate achieved in recent decades in critically burned patients due to the advances in treatment has led to the increase of invasive Candida infections. This explains the growing interest in making an earlier and more accurate diagnosis, as well as more effective treatments to reduce morbidity and mortality of candidaemia in severe burned patients. A review is presented on all aspects of the burned patient, including the predisposition and risk factors for invasive candidiasis, pathogenesis of candidaemia, underlying immunodeficiency, local epidemiology and antifungal susceptibility, evolution and prognostic factors, as well as other non-Candida yeast infections. Finally, we include specific data on our local experience in the management of candidaemia in severe burned patients, which may serve to quantify the problem, place it in context, and offer a realistic perspective. Copyright © 2016 Asociación Española de Micología. Publicado por Elsevier España, S.L.U. All rights reserved.

  10. Molecular architecture of the yeast Mediator complex

    Science.gov (United States)

    Robinson, Philip J; Trnka, Michael J; Pellarin, Riccardo; Greenberg, Charles H; Bushnell, David A; Davis, Ralph; Burlingame, Alma L; Sali, Andrej; Kornberg, Roger D

    2015-01-01

    The 21-subunit Mediator complex transduces regulatory information from enhancers to promoters, and performs an essential role in the initiation of transcription in all eukaryotes. Structural information on two-thirds of the complex has been limited to coarse subunit mapping onto 2-D images from electron micrographs. We have performed chemical cross-linking and mass spectrometry, and combined the results with information from X-ray crystallography, homology modeling, and cryo-electron microscopy by an integrative modeling approach to determine a 3-D model of the entire Mediator complex. The approach is validated by the use of X-ray crystal structures as internal controls and by consistency with previous results from electron microscopy and yeast two-hybrid screens. The model shows the locations and orientations of all Mediator subunits, as well as subunit interfaces and some secondary structural elements. Segments of 20–40 amino acid residues are placed with an average precision of 20 Å. The model reveals roles of individual subunits in the organization of the complex. DOI: http://dx.doi.org/10.7554/eLife.08719.001 PMID:26402457

  11. Yeast peroxisomes: structure, functions and biotechnological opportunities.

    Science.gov (United States)

    Sibirny, Andriy A

    2016-06-01

    Peroxisomes are ubiquitous organelles found in most eukaryotic cells. In yeasts, peroxisomes play important roles in cell metabolism, especially in different catabolic processes including fatty acid β-oxidation, the glyoxylic shunt and methanol metabolism, as well as some biosynthetic processes. In addition, peroxisomes are the compartment in which oxidases and catalase are localized. New peroxisomes mainly arise by fission of pre-existing ones, although they can also be formed from the endoplasmic reticulum (ER). Peroxisomes consist of matrix-soluble proteins and membrane proteins known as peroxins. A total of 34 PEX peroxin genes and proteins have been identified to date. and their functions have been elucidated. Protein import into peroxisomes depends on peroxins and requires specific signals in the structure of transported proteins: PTS1, PTS2 and mPTS. The mechanisms of metabolite penetration into peroxisomes are still poorly understood. Peroxisome number and the volume occupied by these organelles are tightly regulated. Methanol, fatty acids and methylamine act as efficient peroxisome proliferators, whereas glucose and ethanol induce peroxisome autophagic degradation (pexophagy). To date, 42 Atg proteins involved in pexophagy are known. Catabolism and alcoholic fermentation of the major pentose sugar, xylose, depend on peroxisomal enzymes. Overexpression of peroxisomal transketolase and transaldolase activates xylose fermentation. Peroxisomes could be useful as target organelles for overexpression of foreign toxic proteins. © FEMS 2016. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  12. Electrochemical regulation of budding yeast polarity.

    Directory of Open Access Journals (Sweden)

    Armin Haupt

    2014-12-01

    Full Text Available Cells are naturally surrounded by organized electrical signals in the form of local ion fluxes, membrane potential, and electric fields (EFs at their surface. Although the contribution of electrochemical elements to cell polarity and migration is beginning to be appreciated, underlying mechanisms are not known. Here we show that an exogenous EF can orient cell polarization in budding yeast (Saccharomyces cerevisiae cells, directing the growth of mating projections towards sites of hyperpolarized membrane potential, while directing bud emergence in the opposite direction, towards sites of depolarized potential. Using an optogenetic approach, we demonstrate that a local change in membrane potential triggered by light is sufficient to direct cell polarization. Screens for mutants with altered EF responses identify genes involved in transducing electrochemical signals to the polarity machinery. Membrane potential, which is regulated by the potassium transporter Trk1p, is required for polarity orientation during mating and EF response. Membrane potential may regulate membrane charges through negatively charged phosphatidylserines (PSs, which act to position the Cdc42p-based polarity machinery. These studies thus define an electrochemical pathway that directs the orientation of cell polarization.

  13. Electrochemical Regulation of Budding Yeast Polarity

    Science.gov (United States)

    Piel, Matthieu; Chang, Fred; Minc, Nicolas

    2014-01-01

    Cells are naturally surrounded by organized electrical signals in the form of local ion fluxes, membrane potential, and electric fields (EFs) at their surface. Although the contribution of electrochemical elements to cell polarity and migration is beginning to be appreciated, underlying mechanisms are not known. Here we show that an exogenous EF can orient cell polarization in budding yeast (Saccharomyces cerevisiae) cells, directing the growth of mating projections towards sites of hyperpolarized membrane potential, while directing bud emergence in the opposite direction, towards sites of depolarized potential. Using an optogenetic approach, we demonstrate that a local change in membrane potential triggered by light is sufficient to direct cell polarization. Screens for mutants with altered EF responses identify genes involved in transducing electrochemical signals to the polarity machinery. Membrane potential, which is regulated by the potassium transporter Trk1p, is required for polarity orientation during mating and EF response. Membrane potential may regulate membrane charges through negatively charged phosphatidylserines (PSs), which act to position the Cdc42p-based polarity machinery. These studies thus define an electrochemical pathway that directs the orientation of cell polarization. PMID:25548923

  14. Cytotoxic dehydromonacolins from red yeast rice.

    Science.gov (United States)

    Zhu, Lin; Yau, Lee-Fong; Lu, Jing-Guang; Zhu, Guo-Yuan; Wang, Jing-Rong; Han, Quan-Bin; Hsiao, Wen-Luan; Jiang, Zhi-Hong

    2012-02-01

    Two new dehydromonacolins (1 and 3), together with nine known monacolins (4-12), were isolated from red yeast rice. Compounds 4-6 were isolated from a natural resource for the first time. Their structures were elucidated by means of NMR and mass spectroscopic analyses. The structure of dehydromonacolin N (1) was further confirmed by its semisynthesis from monacolin K (lovastatin) (11). Dehydromonacolin J (2), an intermediate in the semisynthesis of 1, was obtained as a new dehydromonacolin. The structure of dehydromonacolin L (3) was also confirmed by an elimination reaction of monacolin L (12). Compound 1, possessing a C2 side chain, is unprecedented in the natural monacolin family and exhibited moderate cytotoxic activity against Hep G2, Caco-2, and MCF-7 cancer cell lines. Dehydromonacolin K (8) demonstrated the most potent cytotoxicity to all three of these cell lines. The structure-activity relationship of natural and synthesized monacolins was discussed. This is the first report on the cytotoxic effects of dehydromonacolins.

  15. Silver tolerance and accumulation in yeasts.

    Science.gov (United States)

    Kierans, M; Staines, A M; Bennett, H; Gadd, G M

    1991-01-01

    Debaryomyces hansenii (NCYC 459 and strain 75-21), Candida albicans (3153A), Saccharomyces cerevisiae (X2180-1B), Rhodotorula rubra (NCYC 797) and Aureobasidium pullulans (IMI 45533 and ATCC 42371) were grown on solid medium supplemented with varying concentrations of AgNO3. Although Ag+ is highly toxic towards yeasts, growth on solid media was still possible at Ag concentrations of 1-2 mM. Further subculture on higher Ag concentrations (up to 5 mM) resulted in elevated tolerance. The extent of Ag tolerance depended on whether Ag-containing plates were exposed to light prior to inoculation since light-mediated reduction of Ag+ to Ag0 resulted in the production of a less toxic silver species. Experimental organisms exhibited blackening of colonies and the surrounding agar during growth on AgNO3-containing medium especially at the highest Ag concentrations tested. All organisms accumulated Ag from the medium; electron microscopy revealed that silver was deposited as electron-dense granules in and around cell walls and in the external medium. X-ray microprobe analysis indicated that these granules were metallic Ag0 although AgCl was also present in some organisms. Volatile and non-volatile reducing compounds were produced by several test organisms which presumably effected Ag+ reduction to Ag0.

  16. X-ray irradiation of yeast cells

    Science.gov (United States)

    Masini, Alessandra; Batani, Dimitri; Previdi, Fabio; Conti, Aldo; Pisani, Francesca; Botto, Cesare; Bortolotto, Fulvia; Torsiello, Flavia; Turcu, I. C. Edmond; Allott, Ric M.; Lisi, Nicola; Milani, Marziale; Costato, Michele; Pozzi, Achille; Koenig, Michel

    1997-10-01

    Saccharomyces Cerevisiae yeast cells were irradiated using the soft X-ray laser-plasma source at Rutherford Laboratory. The aim was to produce a selective damage of enzyme metabolic activity at the wall and membrane level (responsible for fermentation) without interfering with respiration (taking place in mitochondria) and with nuclear and DNA activity. The source was calibrated by PIN diodes and X-ray spectrometers. Teflon stripes were chosen as targets for the UV laser, emitting X-rays at about 0.9 keV, characterized by a very large decay exponent in biological matter. X-ray doses to the different cell compartments were calculated following a Lambert-Bouguet-Beer law. After irradiation, the selective damage to metabolic activity at the membrane level was measured by monitoring CO2 production with pressure silicon detectors. Preliminary results gave evidence of pressure reduction for irradiated samples and non-linear response to doses. Also metabolic oscillations were evidenced in cell suspensions and it was shown that X-ray irradiation changed the oscillation frequency.

  17. DNA replication induces compositional biases in yeast.

    Science.gov (United States)

    Marsolier-Kergoat, Marie-Claude; Goldar, Arach

    2012-03-01

    Asymmetries intrinsic to the process of DNA replication are expected to cause differences in the substitution patterns of the leading and the lagging strands and to induce compositional biases. These biases have been detected in the majority of eubacterial genomes but rarely in eukaryotes. Only in the human genome, the activity of a minority of replication origins seems to generate compositional biases. In this work, we provide evidence for replication-associated GC and TA skews in the genomes of two yeast species, Saccharomyces cerevisiae and Kluyveromyces lactis, whereas the data for the Schizosaccharomyces pombe genome are less conclusive. In contrast with the genomes of Homo sapiens and of the majority of eubacteria, the leading strand is enriched in cytosine and adenine in both S. cerevisiae and K. lactis. We observed significant variations across the interorigin intervals of several substitution rates in the S. cerevisiae lineage since its divergence from S. paradoxus. We also found that the S. cerevisiae genome is far from compositional equilibrium and that its present compositional biases are due to substitution rates operating before its divergence from S. paradoxus. Finally, we observed that replication and transcription tend to be cooriented in the S. cerevisiae genome, especially for genes encoding subunits of protein complexes. Taken together, our results suggest that replication-related compositional biases may be a feature of many eukaryotic genomes despite the stochastic nature of the firing of replication origins in these genomes.

  18. Yeast diversity and novel yeast D1/D2 sequences from corn phylloplane obtained by a culture-independent approach.

    Science.gov (United States)

    Nasanit, Rujikan; Jaibangyang, Sopin; Tantirungkij, Manee; Limtong, Savitree

    2016-12-01

    Culture-independent techniques have recently been used for evaluation of microbial diversity in the environment since it addresses the problem of unculturable microorganisms. In this study, the diversity of epiphytic yeasts from corn (Zea mays Linn.) phylloplanes in Thailand was investigated using this technique and sequence-based analysis of the D1/D2 domains of the large subunit ribosomal DNA sequences. Thirty-seven samples of corn leaf were collected randomly from 10 provinces. The DNA was extracted from leaf washing samples and the D1/D2 domains were amplified. The PCR products were cloned and then screened by colony PCR. A total of 1049 clones were obtained from 37 clone libraries. From this total, 329 clones (213 sequences) were closely related to yeast strains in the GenBank database, and they were clustered into 77 operational taxonomic units (OTUs) with a similarity threshold of 99 %. The majority of sequences (98.5 %) were classified into the phylum Basidiomycota. Sixteen known yeast species were identified. Interestingly, more than 65 % of the D1/D2 sequences obtained by this technique were suggested to be sequences from new yeast taxa. The predominant yeast sequences detected belonged to the order Ustilaginales with relative frequency of 68.0 %. The most common known yeast species detected on the leaf samples were Pseudozyma hubeiensis pro tem. and Moesziomyces antarcticus with frequency of occurrence of 24.3 and 21.6 %, respectively.

  19. Red yeasts and carotenoid production: outlining a future for non-conventional yeasts of biotechnological interest.

    Science.gov (United States)

    Mannazzu, Ilaria; Landolfo, Sara; Lopes da Silva, Teresa; Buzzini, Pietro

    2015-11-01

    Carotenoids are one of the most common classes of pigments that occur in nature. Due to their biological properties, they are widely used in phytomedicine and in the chemical, pharmaceutical, cosmetic, food and feed industries. Accordingly, their global market is continuously growing, and it is expected to reach about US$1.4 billion in 2018. Carotenoids can be easily produced by chemical synthesis, although their biotechnological production is rapidly becoming an appealing alternative to the chemical route, partly due to consumer concerns against synthetic pigments. Among the yeasts, and apart from the pigmented species Phaffia rhodozyma (and its teleomorph Xanthophyllomyces dendrorhous), a handful of species of the genera Rhodosporidium, Rhodotorula, Sporobolomyces and Sporidiobolus are well known carotenoid producers. These are known as 'red yeasts', and their ability to synthesize mixtures of carotenoids from low-cost carbon sources has been broadly studied recently. Here, in agreement with the renewed interest in microbial carotenoids, the recent literature is reviewed regarding the taxonomy of the genera Rhodosporidium, Rhodotorula, Sporobolomyces and Sporidiobolus, the stress factors that influence their carotenogenesis, and the most advanced analytical tools for evaluation of carotenoid production. Moreover, a synopsis of the molecular and "-omic" tools available for elucidation of the metabolic pathways of the microbial carotenoids is reported.

  20. Metals uptake by live yeast and heat-modified yeast residue

    Directory of Open Access Journals (Sweden)

    Geórgia Labuto

    2015-07-01

    Full Text Available This study evaluated the biosorption of Cd2+, Cr3+, Pb2+ and Cu2+ at pHs 3, 4, 5 and 6 for Saccharomyces cerevisiae both alive and biologically inactivated by different heating procedures (oven, autoclave or spray dry technique originated from alcohol industry. The material inactivated by autoclave (IA, at 120°C, 30 min had the best performance for metals uptake: 1.88 ± 0.07 (Cu2+, 2.22 ± 0.02 (Cr3+ and 1.57 ± 0.08 g kg-1 (Pb2+. For Cd2+; while the material inactivated by spray dry (RY presented the higher sorption capacity, 2.30 ± 0.08 g kg-1. The sorption studies showed that the biosorbent materials presented different sorption capacities and an ideal sorption pH. The sorption sites were investigated by potentiometric titration and FT-IR and showed that different heating processes used to inactivate biological samples produce materials with different characteristics and with a diverse sorption capacity due to modification of the available sorption sites. This suggests that inactivation by heating can be an alternative to improve the performance of biosorbents. The main sorption sites for each material were phenolic for live yeast (LY and carboxylic for yeast inactivated by heating in an autoclave (IA.