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Sample records for bakers yeast

  1. 21 CFR 172.898 - Bakers yeast glycan.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Bakers yeast glycan. 172.898 Section 172.898 Food... Multipurpose Additives § 172.898 Bakers yeast glycan. Bakers yeast glycan may be safely used in food in accordance with the following conditions: (a) Bakers yeast glycan is the comminuted, washed, pasteurized, and...

  2. 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... Listing of Specific Substances Affirmed as GRAS § 184.1983 Bakers yeast extract. (a) Bakers yeast extract... a selected strain of yeast, Saccharomyces cerevisiae. It may be concentrated or dried. (b) The...

  3. 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 ...

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

    African Journals Online (AJOL)

    STORAGESEVER

    2010-05-24

    May 24, 2010 ... evaluate the effect of using Baker's yeast produced using date syrup as .... Gas production power (ml/20g dough) for baker's yeasts (LSD Test*). Incubation ... Brain (2005) indicated that a falling number value of 350 s or longer ...

  5. 21 CFR 172.325 - Bakers yeast protein.

    Science.gov (United States)

    2010-04-01

    ... and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) FOOD FOR HUMAN CONSUMPTION (CONTINUED) FOOD ADDITIVES PERMITTED FOR DIRECT ADDITION TO FOOD FOR HUMAN CONSUMPTION Special Dietary and Nutritional Additives § 172.325 Bakers yeast protein. Bakers yeast protein may be...

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

    DEFF Research Database (Denmark)

    Dahl, Allan Carsten; Madsen, Jørgen Øgaard

    1998-01-01

    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......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......-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...

  7. S-adenosylmethionine decarboxylase from baker's yeast.

    Science.gov (United States)

    Pösö, H; Sinervirta, R; Jänne, J

    1975-01-01

    1. S-Adenosyl-L-methionine decarboxylase (S-adenosyl-L-methionine carboxy-lyase, EC 4.1.1.50) was purified more than 1100-fold from extracts of Saccharomyces cerevisiae by affinity chromatography on columns of Sepharose containing covalently bound methylglyoxal bis(guanylhydrazone) (1,1'[(methylethanediylidene)dinitrilo]diguanidine) [Pegg, (1974) Biochem J. 141, 581-583]. The final preparation appeared to be homogeneous on polyacrylamide-gel electrophoresis at pH 8.4. 2. S-Adenosylmethionine decarboxylase activity was completely separated from spermidine synthase activity [5'-deoxyadenosyl-(5'),3-aminopropyl-(1),methylsulphonium-salt-putrescine 3-aminopropyltransferase, EC 2.5.1.16] during the purification procedure. 3. Adenosylmethionine decarboxylase activity from crude extracts of baker's yeast was stimulated by putrescine, 1,3-diamino-propane, cadaverine (1,5-diaminopentane) and spermidine; however, the purified enzyme, although still stimulated by the diamines, was completely insensitive to spermidine. 4. Adenosylmethionine decarboxylase has an apparent Km value of 0.09 mM for adenosylmethionine in the presence of saturating concentrations of putrescine. The omission of putrescine resulted in a five-fold increase in the apparent Km value for adenosylmethionine. 5. The apparent Ka value for putrescine, as the activator of the reaction, was 0.012 mM. 6. Methylglyoxal bis(guanylhydrazone) and S-methyladenosylhomocysteamine (decarboxylated adenosylmethionine) were powerful inhibitors of the enzyme. 7. Adenosylmethionine decarboxylase from baker's yeast was inhibited by a number of conventional carbonyl reagents, but in no case could the inhibition be reversed with exogenous pyridoxal 5'-phosphate. PMID:1108876

  8. Production of baker's yeast using date juice.

    Science.gov (United States)

    Beiroti, A; Hosseini, S N

    2007-07-01

    Baker's yeast is an important additive among the products which improves bread quality and for present time is being produced in different countries by batch, fed batch or continuous cultures. Saccharomyces cerevisiae is used in fermentation of starch in dough, giving a favourable taste and produces a variety of vitamins and proteins. The main ingredient in yeast production is carbon source such as beet molasses, cane molasses, and so on. Since beet molasses has other major function as in high yield alcohol production and also due to the bioenvironmental issues and related wastewater treatment, the use of other carbohydrate sources may be considered. One of these carbohydrate sources is date which is wasted a great deal annually in this country (Iran) . In this study, the capability of date to act as a suitable carbon sources was investigated. The waste date turned into juice and consequently production and growth rate of Sacchromyces cervisiae were studied with this juice. A maximum possible yield of 50% was obtained by the optimum medium (P3), at pH 3.4, 30 degrees C, 1.4 vvm aeration rate and agitation of 500 r/min.

  9. Heuristic Sensitivity Analysis for Baker's Yeast Model Parameters

    OpenAIRE

    Leão, Celina P.; Soares, Filomena O.

    2004-01-01

    The baker's yeast, essentially composed by living cells of Saccharomyces cerevisiae, used in the bread making and beer industries as a microorganism, has an important industrial role. The simulation procedure represents then a necessary tool to understand clearly the baker's yeast fermentation process. The use of mathematical models based on mass balance equations requires the knowledge of the reaction kinetics, thermodynamics, and transport and physical properties. Models may be more or less...

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

    African Journals Online (AJOL)

    55.8 to161.6mlh g , respectively. Bread baked from different baker's yeasts were not significantly different (p>0.05) in their crumb structure and texture. However, significant differences were found in terms of crust color, loaf symmetry and overall acceptability. The staling rate of bread samples correlated positively with yeast's ...

  11. Bakers yeast-mediated transformations of alpha-keto epoxides

    CSIR Research Space (South Africa)

    Meth-Cohn, O

    1994-06-07

    Full Text Available Alpha beta-Epoxy ketones on treatment with baker's yeast yield different types of products depending on their substitution. Small groups such as H or Me attached at the epoxy end protect that end from attack. Thus, 1-acyl epoxides with H, methyl...

  12. Isolation of a tyrosine-activating enzyme from baker's yeast

    NARCIS (Netherlands)

    Ven, A.M. van de; Koningsberger, V.V.; Overbeek, J.Th.G.

    1958-01-01

    The extracts of ether-CO2-frozen baker's yeast contain enzymes that catalyze the ATP-linked amino acid activation by way of pyrophosphate elimination. From the extract a tyrosine-activating enzyme could be isolated, which, judging from ultracentrifugation and electrophoretic data, was about 70% pure

  13. Genetic and phenotypic characteristics of baker's yeast: relevance to baking.

    Science.gov (United States)

    Randez-Gil, Francisca; Córcoles-Sáez, Isaac; Prieto, José A

    2013-01-01

    Yeasts rarely encounter ideal physiological conditions during their industrial life span; therefore, their ability to adapt to changing conditions determines their usefulness and applicability. This is especially true for baking strains of Saccharomyces cerevisiae. The success of this yeast in the ancient art of bread making is based on its capacity to rapidly transform carbohydrates into CO2 rather than its unusual resistance to environmental stresses. Moreover, baker's yeast must exhibit efficient respiratory metabolism during yeast manufacturing, which determines biomass yield. However, optimal growth conditions often have negative consequences in other commercially important aspects, such as fermentative power or stress tolerance. This article reviews the genetic and physiological characteristics of baking yeast strains, emphasizing the activation of regulatory mechanisms in response to carbon source and stress signaling and their importance in defining targets for strain selection and improvement.

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

    DEFF Research Database (Denmark)

    Brochado, Ana Rita; Matos, Cláudia; Møller, Birger L.

    2010-01-01

    Background: Vanillin is one of the most widely used flavouring agents, originally obtained from cured seed pods of the vanilla orchid Vanilla planifolia. 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. In this study we aimed at engineering this vanillin cell factory towards improved productivity and thereby at developing an attractive alternative to chemical synthesis. Results: Expression of a glycosyltransferase from Arabidopsis...

  15. Accumulation of gold using Baker's yeast, Saccharomyces cerevisiae

    International Nuclear Information System (INIS)

    Roy, Kamalika; Lahiri, Susanta; Sinha, P.

    2006-01-01

    Authors have reported preconcentration of 152 Eu, a long-lived fission product, by yeast cells, Saccharomyces cerevisiae. Gold being a precious metal is used in electroplating, hydrogenation catalyst, etc. Heterogeneous composition of samples and low concentration offers renewed interest in its selective extraction of gold using various extractants. Gold can be recovered from different solutions using various chemical reagents like amines, organophosphorus compounds, and extractants containing sulphur as donor atom, etc. In the present work, two different strains of baker's yeast, Saccharomyces cerevisiae have been used to study the preconcentration of gold at various experimental conditions

  16. Removal of heavy metal from industrial effluents using Baker's yeast

    Science.gov (United States)

    Ferdous, Anika; Maisha, Nuzhat; Sultana, Nayer; Ahmed, Shoeb

    2016-07-01

    Bioremediation of wastewater containing heavy metals is one of the major challenges in environmental biotechnology. Heavy metals are not degraded and as a result they remain in the ecosystem, and pose serious health hazards as it comes in contact with human due to anthropogenic activities. Biological treatment with various microorganisms has been practiced widely in recent past, however, accessing and maintaining the microorganisms have always been a challenge. Microorganisms like Baker's yeast can be very promising biosorbents as they offer high surface to volume ratio, large availability, rapid kinetics of adsorption and desorption and low cost. The main aim of this study is to evaluate the applicability of the biosorption process using baker's yeast. Here we present an experimental investigation of biosorption of Chromium (Cr) from water using commercial Baker's Yeast. It was envisaged that yeast, dead or alive, would adsorb heavy metals, however, operating parameters could play vital roles in determining the removal efficiency. Parameters, such as incubation time, pH, amount of biosorbent and heavy metal concentration were varied to investigate the impacts of those parameters on removal efficiency. Rate of removal was found to be inversely proportional to the initial Cr (+6) concentrations but the removal rate per unit biomass was a weakly dependent on initial Cr(+6) concentrations. Biosorption process was found to be more efficient at lower pH and it exhibited lower removal with the increase in solution pH. The optimum incubation time was found to be between 6-8 hours and optimum pH for the metal ion solution was 2. The effluents produced in leather industries are the major source of chromium pollution in Bangladesh and this study has presented a very cost effective yet efficient heavy metal removal approach that can be adopted for such kind of wastewater.

  17. Novel baker's yeast catalysed hydride reduction of an epoxide moiety

    CSIR Research Space (South Africa)

    Horak, RM

    1995-02-27

    Full Text Available 8. This was successfully prepared by the coupling 4 of valeric acid chloride to Meldrum' s acid to yield the C-acyl derivative 6. Compound 6 was treated with SO2Ci 2 yielding the chloro acyl derivative of Meldrum...) O D (8) (v) + O2 N/~/CHO Reagents: (i) SOCI2, 70%, (ii) Meldrum's acid, pyridine, 80%, (iii) SO2C12, 65%, (iv) D20, Ac20, 20%, (v) K-t-butoxide, 20%, (vi) Baker's yeast, 12%. Scheme 3 The deuterium labelled...

  18. Optimization of the flux values in multichannel ceramic membrane microfiltration of Baker`s yeast suspension

    Directory of Open Access Journals (Sweden)

    Milović Nemanja R.

    2016-01-01

    Full Text Available The objective of this work was to estimate the effects of the operating parameters on the baker's yeast microfiltration through multichannel ceramic membrane. The selected parameters were transmembrane pressure, suspension feed flow, and initial suspension concentration. In order to investigate the influence and interaction effects of these parameters on the microfiltration operation, two responses have been chosen: average permeate flux and flux decline. The Box-Behnken experimental design and response surface methodology was used for result processing and process optimization. According to the obtained results, the most important parameter influencing permeate flux during microfiltration is the initial suspension concentration. The maximum average flux value was achieved at an initial concentration of 0.1 g/L, pressure around 1.25 bars and a flow rate at 16 L/h. [Projekat Ministarstva nauke Republike Srbije, br. TR 31002

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

    Science.gov (United States)

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

    2010-11-08

    Vanillin is one of the most widely used flavouring agents, originally obtained from cured seed pods of the vanilla orchid Vanilla planifolia. 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. In this study we aimed at engineering this vanillin cell factory towards improved productivity and thereby at developing an attractive alternative to chemical synthesis. Expression of a glycosyltransferase from Arabidopsis thaliana in the vanillin producing S. cerevisiae strain served to decrease product toxicity. An in silico metabolic engineering strategy of this vanillin glucoside producing strain was designed using a set of stoichiometric modelling tools applied to the yeast genome-scale metabolic network. Two targets (PDC1 and GDH1) were selected for experimental verification resulting in four engineered strains. Three of the mutants showed up to 1.5 fold higher vanillin β-D-glucoside yield in batch mode, while continuous culture of the Δpdc1 mutant showed a 2-fold productivity improvement. This mutant presented a 5-fold improvement in free vanillin production compared to the previous work on de novo vanillin biosynthesis in baker's yeast. Use of constraints corresponding to different physiological states was found to greatly influence the target predictions given minimization of metabolic adjustment (MOMA) as biological objective function. In vivo verification of the targets, selected based on their predicted metabolic adjustment, successfully led to overproducing strains. Overall, we propose and demonstrate a framework for in silico design and target selection for improving microbial cell factories.

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

    Science.gov (United States)

    2010-01-01

    Background Vanillin is one of the most widely used flavouring agents, originally obtained from cured seed pods of the vanilla orchid Vanilla planifolia. 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. In this study we aimed at engineering this vanillin cell factory towards improved productivity and thereby at developing an attractive alternative to chemical synthesis. Results Expression of a glycosyltransferase from Arabidopsis thaliana in the vanillin producing S. cerevisiae strain served to decrease product toxicity. An in silico metabolic engineering strategy of this vanillin glucoside producing strain was designed using a set of stoichiometric modelling tools applied to the yeast genome-scale metabolic network. Two targets (PDC1 and GDH1) were selected for experimental verification resulting in four engineered strains. Three of the mutants showed up to 1.5 fold higher vanillin β-D-glucoside yield in batch mode, while continuous culture of the Δpdc1 mutant showed a 2-fold productivity improvement. This mutant presented a 5-fold improvement in free vanillin production compared to the previous work on de novo vanillin biosynthesis in baker's yeast. Conclusion Use of constraints corresponding to different physiological states was found to greatly influence the target predictions given minimization of metabolic adjustment (MOMA) as biological objective function. In vivo verification of the targets, selected based on their predicted metabolic adjustment, successfully led to overproducing strains. Overall, we propose and demonstrate a framework for in silico design and target selection for improving microbial cell factories. PMID:21059201

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

    Directory of Open Access Journals (Sweden)

    Hansen Jørgen

    2010-11-01

    Full Text Available Abstract Background Vanillin is one of the most widely used flavouring agents, originally obtained from cured seed pods of the vanilla orchid Vanilla planifolia. 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. In this study we aimed at engineering this vanillin cell factory towards improved productivity and thereby at developing an attractive alternative to chemical synthesis. Results Expression of a glycosyltransferase from Arabidopsis thaliana in the vanillin producing S. cerevisiae strain served to decrease product toxicity. An in silico metabolic engineering strategy of this vanillin glucoside producing strain was designed using a set of stoichiometric modelling tools applied to the yeast genome-scale metabolic network. Two targets (PDC1 and GDH1 were selected for experimental verification resulting in four engineered strains. Three of the mutants showed up to 1.5 fold higher vanillin β-D-glucoside yield in batch mode, while continuous culture of the Δpdc1 mutant showed a 2-fold productivity improvement. This mutant presented a 5-fold improvement in free vanillin production compared to the previous work on de novo vanillin biosynthesis in baker's yeast. Conclusion Use of constraints corresponding to different physiological states was found to greatly influence the target predictions given minimization of metabolic adjustment (MOMA as biological objective function. In vivo verification of the targets, selected based on their predicted metabolic adjustment, successfully led to overproducing strains. Overall, we propose and demonstrate a framework for in silico design and target selection for improving microbial cell factories.

  2. Effect of inhibitors on acid production by baker's yeast.

    Science.gov (United States)

    Sigler, K; Knotková, A; Kotyk, A

    1978-01-01

    Glucose-induced acid extrusion, respiration and anaerobic fermentation in baker's yeast was studied with the aid of sixteen inhibitors. Uranyl(2+) nitrate affected the acid extrusion more anaerobically than aerobically; the complexing of Mg2+ and Ca2+ by EDTA at the membrane had no effect. Inhibitors of glycolysis (iodoacetamide, N-ethylmaleimide, fluoride) suppressed acid production markedly, and so did the phosphorylation-blocking arsenate. Fluoroacetate, inhibiting the citric-acid cycle, had no effect. Inhibition by uncouplers depended on their pKa values: 2,4,6-trinitrophenol (pKa 0.4) less than 2,4-dinitrophenol (4.1) less than azide (4.7) less than 3-chlorophenylhydrazonomalononitrile (6.0). Inhibition by trinitrophenol was only slightly increased by its acetylation. Cyanide and nonpermeant oligomycin showed practically no effect; inhibition by dicyclohexylcarbodiimide was delayed but potent. The concentration profiles of inhibition of acid production differed from those of respiration and fermentation. Thus, though the acid production is a metabolically dependent process, it does not reflect the intensity of metabolism, except partly in the first half of glycolysis.

  3. Treatment of the baker's yeast wastewater by electrocoagulation

    International Nuclear Information System (INIS)

    Kobya, M.; Delipinar, S.

    2008-01-01

    In the laboratory-scale experiments, treatment of baker's yeast production wastewater has been investigated by electrocoagulation (EC) using a batch reactor. Effects of the process variables such as pH, electrode material (Fe and Al), current density, and operating time are investigated in terms of removal efficiencies of chemical oxygen demand (COD), total organic carbon (TOC), turbidity, and operating cost, respectively. The maximum removal efficiencies of COD, TOC and turbidity under optimal operating conditions, i.e., pH 6.5 for Al electrode and pH 7 for Fe electrode, current density of 70 A/m 2 and operating time of 50 min were 71, 53 and 90% for Al electrode and 69, 52 and 56% for Fe electrode, respectively. Al electrode gave 4.4 times higher removal efficiency of turbidity than Fe electrode due to interference from color of dissolved iron. The operating costs for Al and Fe electrodes in terms of $/m 3 or $/kg COD were 1.54 and 0.82, 0.51 and 0.27, respectively

  4. Kazachstania gamospora and Wickerhamomyces subpelliculosus: Two alternative baker's yeasts in the modern bakery.

    Science.gov (United States)

    Zhou, Nerve; Schifferdecker, Anna Judith; Gamero, Amparo; Compagno, Concetta; Boekhout, Teun; Piškur, Jure; Knecht, Wolfgang

    2017-06-05

    Saccharomyces cerevisiae, the conventional baker's yeast, remains the most domesticated yeast monopolizing the baking industry. Its rapid consumption of sugars and production of CO 2 are the most important attributes required to leaven the dough. New research attempts highlight that these attributes are not unique to S. cerevisiae, but also found in several non-conventional yeast species. A small number of these yeast species with similar properties have been described, but remain poorly studied. They present a vast untapped potential for the use as leavening agents and flavor producers due to their genetic and phylogenetic diversity. We assessed the potential of several non-conventional yeasts as leavening agents and flavor producers in dough-like conditions in the presence of high sugar concentrations and stressful environments mimicking conditions found in flour dough. We tested the capabilities of bread leavening and aroma formation in a microbread platform as well as in a bakery setup. Bread leavened with Kazachstania gamospora and Wickerhamomyces subpelliculosus had better overall results compared to control baker's yeast. In addition, both displayed higher stress tolerance and broader aroma profiles than the control baker's yeast. These attributes are important in bread and other farinaceous products, making K. gamospora and W. subpelliculosus highly applicable as alternative baker's yeasts. Copyright © 2017 Elsevier B.V. All rights reserved.

  5. Kazachstania gamospora and Wickerhamomyces subpelliculosus : Two alternative baker's yeasts in the modern bakery

    NARCIS (Netherlands)

    Zhou, Nerve; Judith Schifferdecker, Anna; Gamero Lluna, Amparo; Compagno, Concetta; Boekhout, Teun; Piškur, Jure; Knecht, Wolfgang

    2017-01-01

    Saccharomyces cerevisiae, the conventional baker's yeast, remains the most domesticated yeast monopolizing the baking industry. Its rapid consumption of sugars and production of CO2 are the most important attributes required to leaven the dough. New research attempts highlight that these attributes

  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. 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.

  8. A novel bread making process using salt-stressed Baker's yeast.

    Science.gov (United States)

    Yeh, Lien-Te; Charles, Albert Linton; Ho, Chi-Tang; Huang, Tzou-Chi

    2009-01-01

    By adjusting the mixing order of ingredients in traditional formula, an innovative bread making process was developed. The effect of salt-stressed Baker's yeast on bread dough of different sugar levels was investigated. Baker's yeast was stressed in 7% salt solution then mixed into dough, which was then evaluated for fermentation time, dough fermentation producing gas, dough expansion, bread specific volumes, and sensory and physical properties. The results of this study indicated that salt-stressed Baker's yeast shortened fermentation time in 16% and 24% sugar dough. Forty minutes of salt stress produced significant amount of gas and increased bread specific volumes. The bread was softer and significantly improved sensory properties for aroma, taste, and overall acceptability were obtained.

  9. 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

    2009-01-01

    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 β-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. PMID:19286778

  10. Uranium uptake by baker's yeast (Saccharomyces cerevisiae) - development of a biological ion exchanger

    International Nuclear Information System (INIS)

    Oost, T.; Schoening, K.U.

    1991-01-01

    The use of micro-organisms for decontamination of, and heavy metal recovery from industrial waste water is a modern, low-cost, and environmentally friendly alternative to the conventional chemical and physical methods. The uptake of uranium by baker's yeast is investigated under the aspect of application in biotechnology. A novel, regenerable biological ion exchanger was produced by immobilisation of the yeast in agar gel. (orig.) [de

  11. Selection and Characterization of Potential Baker's Yeast from Indigenous Resources of Nepal.

    Science.gov (United States)

    Karki, Tika B; Timilsina, Parash Mani; Yadav, Archana; Pandey, Gyanu Raj; Joshi, Yogesh; Bhujel, Sahansila; Adhikari, Rojina; Neupane, Katyayanee

    2017-01-01

    The study aims to isolate the yeast strains that could be used effectively as baker's yeast and compare them with the commercial baker's yeast available in the market of Nepal. A total of 10 samples including locally available sources like fruits, Murcha, and a local tree "Dar" were collected from different localities of Bhaktapur, Kavre, and Syangja districts of Nepal, respectively. Following enrichment and fermentation of the samples, 26 yeast strains were isolated using selective medium Wallerstein Laboratory Nutrient Agar. From the differential tests which included morphological and microscopic observation and physiological and biochemical characterization such as nitrate reduction and lactose utilization tests, 8 strains were selected as possible Saccharomyces strain. The selected strains were further assessed for their efficient leavening ability by tests such as ethanol tolerance, osmotolerance, invertase test, and stress exclusion test. The three most potent strains ENG, MUR3B, and SUG1 isolated from grape, Murcha, and sugarcane, respectively, were used in the fermentation and baking of dough. These strains also carried a possibility of being used as industrial baker's yeast.

  12. Kinetics of alcoholic fermentation during the culturing of bakers' yeast

    Energy Technology Data Exchange (ETDEWEB)

    Franz, B

    1961-01-01

    A synthesis was made of the effects of various factors on the rate of fermentation by Saccharomyces cerevisiae. The rate obeyed the Michaelis-Menten equation, was independent of the concentration of yeast, was maximal at 20/sup 0/ (0.61 ml ethanol/g dry yeast/h), was not significantly affected between pH 6.5 and 3.0 but declined at 3.0, was inhibited by ethanol at a rate proportional to the concentration squared (at ethanol = 12 volume %, the fermentation rate was practically zero), and was enhanced by the addition of phosphorus when a P-poor yeast was employed.

  13. Looking for immunotolerance: a case of allergy to baker's yeast (Saccharomyces cerevisiae).

    Science.gov (United States)

    Pajno, G B; Passalacqua, G; Salpietro, C; Vita, D; Caminiti, L; Barberio, G

    2005-09-01

    We describe one case of baker's yeast true allergy in a boy with previously diagnosed mite-allergy and atopic dermatitis. At the age of 6, being atopic dermatitis and rhinitis well controlled by drugs, he began to experience generalized urticaria and asthma after eating pizza and bread, but only fresh from the oven. The diagnostic workup revealed single sensitization to baker's yeast (Saccharomyces cerevisiae), and a severe systemic reaction also occurred during the prick-by-prick procedure. After discussing with parents, no special dietary restriction was suggested but the use of autoinjectable adrenaline and on demand salbutamol. A diary of symptoms was recorded by means of a visual-analog scale. During the subsequent 2 years, the severity of symptoms was progressively reduced, and presently urticaria has disappeared. Only cough persists, invariantly after eating just-baked and yeast-containing foods. If bread, pizza and cakes are ate more than one hour after preparation, no symptom occur at all. Baker's yeast is a common component of everyday diet and it usually acts as an allergen only by the inhalatory route. We speculate that the continuous exposure to saccharomyces in foods may have lead to an immunotolerance with a progressive reduction of symptoms, whereas why the allergens is active only in ready-baked foods remains unexplained.

  14. Quality parameters and RAPD-PCR differentiation of commercial baker's yeast and hybrid strains.

    Science.gov (United States)

    El-Fiky, Zaki A; Hassan, Gamal M; Emam, Ahmed M

    2012-06-01

    Baker's yeast, Saccharomyces cerevisiae, is a key component in bread baking. Total of 12 commercial baker's yeast and 2 hybrid strains were compared using traditional quality parameters. Total of 5 strains with high leavening power and the 2 hybrid strains were selected and evaluated for their alpha-amylase, maltase, glucoamylase enzymes, and compared using random amplified polymorphic DNA (RAPD). The results revealed that all selected yeast strains have a low level of alpha-amylase and a high level of maltase and glucoamylase enzymes. Meanwhile, the Egyptian yeast strain (EY) had the highest content of alpha-amylase and maltase enzymes followed by the hybrid YH strain. The EY and YH strains have the highest content of glucoamylase enzyme almost with the same level. The RAPD banding patterns showed a wide variation among commercial yeast and hybrid strains. The closely related Egyptian yeast strains (EY and AL) demonstrated close similarity of their genotypes. The 2 hybrid strains were clustered to Turkish and European strains in 1 group. The authors conclude that the identification of strains and hybrids using RAPD technique was useful in determining their genetic relationship. These results can be useful not only for the basic research, but also for the quality control in baking factories. © 2012 Institute of Food Technologists®

  15. The Treasure of the Humble: Lessons from Baker's Yeast

    Science.gov (United States)

    Sitaraman, Ramakrishnan

    2011-01-01

    The study of model organisms is a powerful and proven experimental strategy for understanding biological processes. This paper describes an attempt to utilize advances in yeast molecular biology to enhance student understanding by presenting a more comprehensive view of several interconnected molecular processes in the overall functioning of an…

  16. Development of intra-strain self-cloning procedure for breeding baker's yeast strains.

    Science.gov (United States)

    Nakagawa, Youji; Ogihara, Hiroyuki; Mochizuki, Chisato; Yamamura, Hideki; Iimura, Yuzuru; Hayakawa, Masayuki

    2017-03-01

    Previously reported self-cloning procedures for breeding of industrial yeast strains require DNA from other strains, plasmid DNA, or mutagenesis. Therefore, we aimed to construct a self-cloning baker's yeast strain that exhibits freeze tolerance via an improved self-cloning procedure. We first disrupted the URA3 gene of a prototrophic baker's yeast strain without the use of any marker gene, resulting in a Δura3 homozygous disruptant. Then, the URA3 gene of the parental baker's yeast strain was used as a selection marker to introduce the constitutive TDH3 promoter upstream of the PDE2 gene encoding high-affinity cyclic AMP phosphodiesterase. This self-cloning procedure was performed without using DNA from other Saccharomyces cerevisiae strains, plasmid DNA, or mutagenesis and was therefore designated an intra-strain self-cloning procedure. Using this self-cloning procedure, we succeeded in producing self-cloning baker's yeast strains that harbor the TDH3p-PDE2 gene heterozygously and homozygously, designated TDH3p-PDE2 hetero and TDH3p-PDE2 homo strains, respectively. These self-cloning strains expressed much higher levels of PDE2 mRNA than the parental strain and exhibited higher viability after freeze stress, as well as higher fermentation ability in frozen dough, when compared with the parental strain. The TDH3p-PDE2 homo strain was genetically more stable than the TDH3p-PDE2 hetero strain. These results indicate that both heterozygous and homozygous strains of self-cloning PDE2-overexpressing freeze-tolerant strains of industrial baker's yeast can be prepared using the intra-strain self-cloning procedure, and, from a practical viewpoint, the TDH3p-PDE2 homo strain constructed in this study is preferable to the TDH3p-PDE2 hetero strain for frozen dough baking. Copyright © 2016 The Society for Biotechnology, Japan. Published by Elsevier B.V. All rights reserved.

  17. Post-fermentative production of glutathione by baker's yeast (S. cerevisiae) in compressed and dried forms.

    Science.gov (United States)

    Musatti, Alida; Manzoni, Matilde; Rollini, Manuela

    2013-01-25

    The study was aimed at investigating the best biotransformation conditions to increase intracellular glutathione (GSH) levels in samples of baker's yeast (Saccharomyces cerevisiae) employing either the commercially available compressed and dried forms. Glucose, GSH precursors amino acids, as well as other cofactors, were dissolved in a biotransformation solution and yeast cells were added (5%dcw). Two response surface central composite designs (RSCCDs) were performed in sequence: in the first step the influence of amino acid composition (cysteine, glycine, glutamic acid and serine) on GSH accumulation was investigated; once their formulation was set up, the influence of other components was studied. Initial GSH content was found 0.53 and 0.47%dcw for compressed and dried forms. GSH accumulation ability of baker's yeast in compressed form was higher at the beginning of shelf life, that is, in the first week, and a maximum of 2.04%dcw was obtained. Performance of yeast in dried form was not found satisfactory, as the maximum GSH level was 1.18%dcw. When cysteine lacks from the reaction solution, yeast cells do not accumulate GSH. With dried yeast, the highest GSH yields occurred when cysteine was set at 3 g/L, glycine and glutamic acid at least at 4 g/L, without serine. Employing compressed yeast, the highest GSH yields occurred when cysteine and glutamic acid were set at 2-3 g/L, while glycine and serine higher than 2 g/L. Results allowed to set up an optimal and feasible procedure to obtain GSH-enriched yeast biomass, with up to threefold increase with respect to initial content. Copyright © 2012 Elsevier B.V. All rights reserved.

  18. Metabolism of 2-deoxyglyconic acid in plants and bakers yeast

    International Nuclear Information System (INIS)

    Gakhokidze, R.A.; Beriashvili, L.T.; Chigvinadze, T.D.

    1996-01-01

    During photosynthesis in Phaseolus vulgaris haricot bean and Zea mays leaves, assimilated carbon 14 CO 2 is rapidly incorporated into aldonic acids including 2-deoxygluconic acid whose radioactivity was relatively high. In these plants, radioactive carbon of 2-deoxy-D-gluconic acid prepared from 1-6 14 C-D-glucose is actively involved in the formation of sugars, organic acids, and amino acids. In baking yeast Saccharomyces cerevisiae, the rate of respiration-dependent oxidation of 2-deoxy-D-gluconic acid differs versus the rate of D-glucose oxidation [ru

  19. Overproduction of 2-phenylethanol by industrial yeasts to improve organoleptic properties of bakers' products.

    Science.gov (United States)

    Dueñas-Sánchez, Rafael; Pérez, Ana G; Codón, Antonio C; Benítez, Tahía; Rincón, Ana María

    2014-06-16

    2-Phenylethanol (PEA), an important alcohol derived from phenylalanine, is involved in aroma and flavour of bakers' products. Four spontaneous mutants of an industrial bakers' yeast, V1 strain, were isolated for their resistance to p-fluoro-DL-phenylalanine (PFP), a toxic analogue of L-phenylalanine. Mutants overproduced this amino acid and showed variations in their internal pool for several other amino acids. Moreover, a rise in PEA production after growth in industrial medium (MAB) was observed in three of the mutants, although their growth and fermentative capacities were slightly impaired. However, concentration of PEA remained higher during dough fermentation and also after baking, thus improving taste and aroma in bread. Copyright © 2014 Elsevier B.V. All rights reserved.

  20. Isolation of baker's yeast mutants with proline accumulation that showed enhanced tolerance to baking-associated stresses.

    Science.gov (United States)

    Tsolmonbaatar, Ariunzaya; Hashida, Keisuke; Sugimoto, Yukiko; Watanabe, Daisuke; Furukawa, Shuhei; Takagi, Hiroshi

    2016-12-05

    During bread-making processes, yeast cells are exposed to baking-associated stresses such as freeze-thaw, air-drying, and high-sucrose concentrations. Previously, we reported that self-cloning diploid baker's yeast strains that accumulate proline retained higher-level fermentation abilities in both frozen and sweet doughs than the wild-type strain. Although self-cloning yeasts do not have to be treated as genetically modified yeasts, the conventional methods for breeding baker's yeasts are more acceptable to consumers than the use of self-cloning yeasts. In this study, we isolated mutants resistant to the proline analogue azetidine-2-carboxylate (AZC) derived from diploid baker's yeast of Saccharomyces cerevisiae. Some of the mutants accumulated a greater amount of intracellular proline, and among them, 5 mutants showed higher cell viability than that observed in the parent wild-type strain under freezing or high-sucrose stress conditions. Two of them carried novel mutations in the PRO1 gene encoding the Pro247Ser or Glu415Lys variant of γ-glutamyl kinase (GK), which is a key enzyme in proline biosynthesis in S. cerevisiae. Interestingly, we found that these mutations resulted in AZC resistance of yeast cells and desensitization to proline feedback inhibition of GK, leading to intracellular proline accumulation. Moreover, baker's yeast cells expressing the PRO1 P247S and PRO1 E415K gene were more tolerant to freezing stress than cells expressing the wild-type PRO1 gene. The approach described here could be a practical method for the breeding of proline-accumulating baker's yeasts with higher tolerance to baking-associated stresses. Copyright © 2016 Elsevier B.V. All rights reserved.

  1. Radiation stimulation of yeast crops for increasing output of alcohol and baker yeasts

    International Nuclear Information System (INIS)

    Vlad, E.; Marsheu, P.

    1974-01-01

    The purpose of this study was to stimulate by gamma radiation the existing commercial types of yeast so as to obtain yeasts that would better reflect the substrate and have improved reproductive capacity. The experiments were conducted under ordinary conditions using commercial yeasts received from one factory producing alcohol and bakery yeasts and isolated as pure cultures. Irradiating yeast cultures with small doses (up to 10 krad) was found to stimulate the reproduction and fermenting activity of yeast cells as manifested in increased accumulation of yeast biomass and greater yield of ethyl alcohol. (E.T.)

  2. Active site - a site of binding of affinity inhibitors in baker's yeast inorganic pyrophosphatase

    International Nuclear Information System (INIS)

    Svyato, I.E.; Sklyankina, V.A.; Avaeva, S.M.

    1986-01-01

    The interaction of the enzyme-substrate complex with methyl phosphate, O-phosphoethanolamine, O-phosphopropanolamine, N-acetylphosphoserine, and phosphoglyolic acid, as well as pyrophosphatase, modified by monoesters of phosphoric acid, with pyrophosphate and tripolyphosphate, was investigated. It was shown that the enzyme containing the substrate in the active site does not react with monophosphates, but modified pyrophosphatase entirely retains the ability to bind polyanions to the regulatory site. It is concluded that the inactivation of baker's yeast inorganic pyrophosphatase by monoesters of phosphoric acid, which are affinity inhibitors of it, is the result of modification of the active site of the enzyme

  3. An improved, bias-reduced probabilistic functional gene network of baker's yeast, Saccharomyces cerevisiae.

    Directory of Open Access Journals (Sweden)

    Insuk Lee

    2007-10-01

    Full Text Available Probabilistic functional gene networks are powerful theoretical frameworks for integrating heterogeneous functional genomics and proteomics data into objective models of cellular systems. Such networks provide syntheses of millions of discrete experimental observations, spanning DNA microarray experiments, physical protein interactions, genetic interactions, and comparative genomics; the resulting networks can then be easily applied to generate testable hypotheses regarding specific gene functions and associations.We report a significantly improved version (v. 2 of a probabilistic functional gene network of the baker's yeast, Saccharomyces cerevisiae. We describe our optimization methods and illustrate their effects in three major areas: the reduction of functional bias in network training reference sets, the application of a probabilistic model for calculating confidences in pair-wise protein physical or genetic interactions, and the introduction of simple thresholds that eliminate many false positive mRNA co-expression relationships. Using the network, we predict and experimentally verify the function of the yeast RNA binding protein Puf6 in 60S ribosomal subunit biogenesis.YeastNet v. 2, constructed using these optimizations together with additional data, shows significant reduction in bias and improvements in precision and recall, in total covering 102,803 linkages among 5,483 yeast proteins (95% of the validated proteome. YeastNet is available from http://www.yeastnet.org.

  4. Sugar utilization patterns and respiro-fermentative metabolism in the baker's yeast Torulaspora delbrueckii.

    Science.gov (United States)

    Alves-Araújo, C; Pacheco, A; Almeida, M J; Spencer-Martins, I; Leão, C; Sousa, M J

    2007-03-01

    The highly osmo- and cryotolerant yeast species Torulaspora delbrueckii is an important case study among the non-Saccharomyces yeast species. The strain T. delbrueckii PYCC 5321, isolated from traditional corn and rye bread dough in northern Portugal, is considered particularly interesting for the baking industry. This paper reports the sugar utilization patterns of this strain, using media with glucose, maltose and sucrose, alone or in mixtures. Kinetics of growth, biomass and ethanol yields, fermentation and respiration rates, hydrolase activities and sugar uptake rates were used to infer the potential applied relevance of this yeast in comparison to a conventional baker's strain of Saccharomyces cerevisiae. The results showed that both maltase and maltose transport in T. delbrueckii were subject to glucose repression and maltose induction, whereas invertase was subject to glucose control but not dependent on sucrose induction. A comparative analysis of specific sugar consumption rates and transport capacities suggests that the transport step limits both glucose and maltose metabolism. Specific rates of CO(2) production and O(2) consumption showed a significantly higher contribution of respiration to the overall metabolism in T. delbrueckii than in S. cerevisiae. This was reflected in the biomass yields from batch cultures and could represent an asset for the large-scale production of the former species. This work contributes to a better understanding of the physiology of a non-conventional yeast species, with a view to the full exploitation of T. delbrueckii by the baking industry.

  5. Thermodynamic analysis of fermentation and anaerobic growth of baker's yeast for ethanol production.

    Science.gov (United States)

    Teh, Kwee-Yan; Lutz, Andrew E

    2010-05-17

    Thermodynamic concepts have been used in the past to predict microbial growth yield. This may be the key consideration in many industrial biotechnology applications. It is not the case, however, in the context of ethanol fuel production. In this paper, we examine the thermodynamics of fermentation and concomitant growth of baker's yeast in continuous culture experiments under anaerobic, glucose-limited conditions, with emphasis on the yield and efficiency of bio-ethanol production. We find that anaerobic metabolism of yeast is very efficient; the process retains more than 90% of the maximum work that could be extracted from the growth medium supplied to the chemostat reactor. Yeast cells and other metabolic by-products are also formed, which reduces the glucose-to-ethanol conversion efficiency to less than 75%. Varying the specific ATP consumption rate, which is the fundamental parameter in this paper for modeling the energy demands of cell growth, shows the usual trade-off between ethanol production and biomass yield. The minimum ATP consumption rate required for synthesizing cell materials leads to biomass yield and Gibbs energy dissipation limits that are much more severe than those imposed by mass balance and thermodynamic equilibrium constraints. 2010 Elsevier B.V. All rights reserved.

  6. High-performance mesoporous LiFePO₄ from Baker's yeast.

    Science.gov (United States)

    Zhang, Xudong; Zhang, Xueguang; He, Wen; Sun, Caiyun; Ma, Jingyun; Yuan, Junling; Du, Xiaoyong

    2013-03-01

    Based on the biomineralization assembly concept, a simple and inexpensive biomimetic sol-gel method is found to synthesize high-performance mesoporous LiFePO(4) (HPM-LFP). The key step of this approach is to apply Baker's yeast cells as both a structural template and a biocarbon source. The formation mechanism of ordered hierarchical mesoporous network structure is revealed by characterizing its morphology and microstructure. The HPM-LFP exhibits outstanding electrochemical performances. The HPM-LFP has a high discharge capacity (about 153 mAh g(-1) at a 0.1 C rate), only 2% capacity loss from the initial value after 100 cycles at a current density of 0.1 C. This simple and potentially universal design strategy is currently being pursued in the synthesis of an ideal cathode-active material for high power applications. Copyright © 2012 Elsevier B.V. All rights reserved.

  7. The interaction of uranyl ions with inorganic pyrophosphatase from baker's yeast

    International Nuclear Information System (INIS)

    Bienwald, B.; Heitmann, P.

    1978-01-01

    The interaction of uranyl ions with inorganic pyrophosphatase from baker's yeast was investigated by measurement of their effect on the protein fluorescence. Fluorescence titrations of the native enzyme with uranyl nitrate show that there is a specific binding of uranyl ions to the enzyme. It was deduced that each subunit of the enzyme binds one uranyl ion. The binding constant was estimated to be in the order of 10 7 M -1 . The enzyme which contains a small number of chemically modified carboxyl groups was not able to bind uranyl ions specifically. The modification of carboxyl groups was carried out by use of a water soluble carbodiimide and the nucleophilic reagent N-(2,4-dinitro-phenyl)-hexamethylenediamine. The substrate analogue calcium pyrophosphate displaced the uranyl ions from their binding sites at the enzyme From the results it is concluded that carboxyl groups of the active site are the ligands for the binding of uranyl ions. (author)

  8. Utilization of baker's yeast (Saccharomyces cerevisiae for the production of yeast extract: effects of different enzymatic treatments on solid, protein and carbohydrate recovery

    Directory of Open Access Journals (Sweden)

    TATJANA VUKASINOVIC MILIC

    2007-05-01

    Full Text Available Yeast extract (YE was produced from commercial pressed baker's yeast (active and inactivated using two enzymes: papain and lyticase. The effects of enzyme concentration and hydrolysis time on the recovery of solid, protein and carbohydrate were investigated. Autolysis, as a basic method for cell lysis was also used and the results compared. The optimal extraction conditions were investigated. The optimal concentrations of papain and lyticase were found to be 2.5 % and 0.025 %, respectively.

  9. Improvement of fermentation ability under baking-associated stress conditions by altering the POG1 gene expression in baker's yeast.

    Science.gov (United States)

    Sasano, Yu; Haitani, Yutaka; Hashida, Keisuke; Oshiro, Satoshi; Shima, Jun; Takagi, Hiroshi

    2013-08-01

    During the bread-making process, yeast cells are exposed to many types of baking-associated stress. There is thus a demand within the baking industry for yeast strains with high fermentation abilities under these stress conditions. The POG1 gene, encoding a putative transcription factor involved in cell cycle regulation, is a multicopy suppressor of the yeast Saccharomyces cerevisiae E3 ubiquitin ligase Rsp5 mutant. The pog1 mutant is sensitive to various stresses. Our results suggested that the POG1 gene is involved in stress tolerance in yeast cells. In this study, we showed that overexpression of the POG1 gene in baker's yeast conferred increased fermentation ability in high-sucrose-containing dough, which is used for sweet dough baking. Furthermore, deletion of the POG1 gene drastically increased the fermentation ability in bread dough after freeze-thaw stress, which would be a useful characteristic for frozen dough baking. Thus, the engineering of yeast strains to control the POG1 gene expression level would be a novel method for molecular breeding of baker's yeast. Copyright © 2013 Elsevier B.V. All rights reserved.

  10. Prevention of GABA reduction during dough fermentation using a baker's yeast dal81 mutant.

    Science.gov (United States)

    Ando, Akira; Nakamura, Toshihide

    2016-10-01

    γ-Aminobutyric acid (GABA) is consumed by yeasts during fermentation. To prevent GABA reduction in bread dough, a baker's yeast mutant AY77 deficient in GABA assimilation was characterized and utilized for wheat dough fermentation. An amber mutation in the DAL81 gene, which codes for a positive regulator of multiple nitrogen degradation pathways, was found in the AY77 strain. The qPCR analyses of genes involved in nitrogen utilization showed that transcriptional levels of the UGA1 and DUR3 genes encoding GABA transaminase and urea transporter, respectively, are severely decreased in the AY77 cells. The AY77 strain cultivated by fed-batch culture using cane molasses exhibited inferior gas production during dough fermentation compared to that of wild-type strain AY13. However, when fed with molasses containing 0.5% ammonium sulfate, the mutant strain exhibited gas production comparable to that of the AY13 strain. In contrast to the AY13 strain, which completely consumed GABA in dough within 5 h, the AY77 strain consumed no GABA under either culture condition. Dough fermentation with the dal81 mutant strain should be useful for suppression of GABA reduction in breads. Copyright © 2016 The Society for Biotechnology, Japan. Published by Elsevier B.V. All rights reserved.

  11. Exploration of potential baker's yeast from sugarcane juice: optimization and evaluation.

    Science.gov (United States)

    Mamun-Or-rashid, A N M; Dash, Biplab Kumar; Chowdhury, Md Nurul Abadin; Waheed, Momtaz Fatima; Pramanik, Md Kamruzzaman

    2013-07-01

    The present study was carried out to explore baker's yeasts strains from sugarcane juice to assess its potential in laboratory scale production of breads. Collected juice samples were processed for isolation and identification of yeast strains based on standard cultural, morphological and biochemical characteristics. Among the six isolated strains, four (designated as S1, S2, S5 and S6) were identified as Saccharomyces cerevisiae and the rests (designated S3 and S4) were as S. rouxii. When assessing their CO2 production rates as a measure of their baking potential, S6 was found to produce maximum amount of gas (226.67 mm3 mL(-1)) in sucrose broth, whereas gas produced by S2, S1 and S5 were relatively insignificant (170, 136.67 and 86.67 mm3 mL(-1), respectively). No strain was found to produce undesirable H2S gas responsible for off-flavor. Besides, effects of different physicochemical parameters (e.g., pH, temperature, substrate concentration, incubation period, agitation etc.) on the production of yeast cell-mass were studied. Yield of cell mass was indirectly measured by spectrophotometric method at 550 nm. All the test isolates were found to produce maximum cell mass at a pH range of 4.0 to 5.0 in 2 to 4% molasses broth at 30 degrees C after 4 days of incubation. In the laboratory scale production of bread using composite flour, Isolate-S6 formed significant characteristic texture. Considering overall characteristics, Isolate- S6 was found to be satisfactorily potent for baking purpose.

  12. Improvement of stress tolerance and leavening ability under multiple baking-associated stress conditions by overexpression of the SNR84 gene in baker's yeast.

    Science.gov (United States)

    Lin, Xue; Zhang, Cui-Ying; Bai, Xiao-Wen; Feng, Bing; Xiao, Dong-Guang

    2015-03-16

    During the bread-making process, industrial baker's yeast cells are exposed to multiple baking-associated stresses, such as elevated high-temperature, high-sucrose and freeze-thaw stresses. There is a high demand for baker's yeast strains that could withstand these stresses with high leavening ability. The SNR84 gene encodes H/ACA snoRNA (small nucleolar RNA), which is known to be involved in pseudouridylation of the large subunit rRNA. However, the function of the SNR84 gene in baker's yeast coping with baking-associated stresses remains unclear. In this study, we explored the effect of SNR84 overexpression on baker's yeast which was exposed to high-temperature, high-sucrose and freeze-thaw stresses. These results suggest that overexpression of the SNR84 gene conferred tolerance of baker's yeast cells to high-temperature, high-sucrose and freeze-thaw stresses and enhanced their leavening ability in high-sucrose and freeze-thaw dough. These findings could provide a valuable insight for breeding of novel stress-resistant baker's yeast strains that are useful for baking. Copyright © 2015 Elsevier B.V. All rights reserved.

  13. Treatment of the baker's yeast wastewater by electrocoagulation

    Energy Technology Data Exchange (ETDEWEB)

    Kobya, M. [Department of Environmental Engineering, Gebze Institute of Technology, 41400 Gebze (Turkey)], E-mail: kobya@gyte.edu.tr; Delipinar, S. [Department of Environmental Engineering, Gebze Institute of Technology, 41400 Gebze (Turkey)

    2008-06-15

    In the laboratory-scale experiments, treatment of baker's yeast production wastewater has been investigated by electrocoagulation (EC) using a batch reactor. Effects of the process variables such as pH, electrode material (Fe and Al), current density, and operating time are investigated in terms of removal efficiencies of chemical oxygen demand (COD), total organic carbon (TOC), turbidity, and operating cost, respectively. The maximum removal efficiencies of COD, TOC and turbidity under optimal operating conditions, i.e., pH 6.5 for Al electrode and pH 7 for Fe electrode, current density of 70 A/m{sup 2} and operating time of 50 min were 71, 53 and 90% for Al electrode and 69, 52 and 56% for Fe electrode, respectively. Al electrode gave 4.4 times higher removal efficiency of turbidity than Fe electrode due to interference from color of dissolved iron. The operating costs for Al and Fe electrodes in terms of $/m{sup 3} or $/kg COD were 1.54 and 0.82, 0.51 and 0.27, respectively.

  14. Antioxidant N-acetyltransferase Mpr1/2 of industrial baker's yeast enhances fermentation ability after air-drying stress in bread dough.

    Science.gov (United States)

    Sasano, Yu; Takahashi, Shunsuke; Shima, Jun; Takagi, Hiroshi

    2010-03-31

    During bread-making processes, yeast cells are exposed to multiple stresses. Air-drying stress is one of the most harmful stresses by generation of reactive oxygen species (ROS). Previously, we discovered that the novel N-acetyltransferase Mpr1/2 confers oxidative stress tolerance by reducing intracellular ROS level in Saccharomyces cerevisiae Sigma1278b strain. In this study, we revealed that Japanese industrial baker's yeast possesses one MPR gene. The nucleotide sequence of the MPR gene in industrial baker's yeast was identical to the MPR2 gene in Sigma1278b strain. Gene disruption analysis showed that the MPR2 gene in industrial baker's yeast is involved in air-drying stress tolerance by reducing the intracellular oxidation levels. We also found that expression of the Lys63Arg and Phe65Leu variants with enhanced enzymatic activity and stability, respectively, increased the fermentation ability of bread dough after exposure to air-drying stress compared with the wild-type Mpr1. In addition, our recent study showed that industrial baker's yeast cells accumulating proline exhibited enhanced freeze tolerance in bread dough. Proline accumulation also enhanced the fermentation ability after air-drying stress treatment in industrial baker's yeast. Hence, the antioxidant enzyme Mpr1/2 could be promising for breeding novel yeast strains that are tolerant to air-drying stress. Copyright 2010 Elsevier B.V. All rights reserved.

  15. Enhancement of the proline and nitric oxide synthetic pathway improves fermentation ability under multiple baking-associated stress conditions in industrial baker's yeast

    Directory of Open Access Journals (Sweden)

    Sasano Yu

    2012-04-01

    Full Text Available Abstract Background During the bread-making process, industrial baker's yeast, mostly Saccharomyces cerevisiae, is exposed to baking-associated stresses, such as air-drying and freeze-thaw stress. These baking-associated stresses exert severe injury to yeast cells, mainly due to the generation of reactive oxygen species (ROS, leading to cell death and reduced fermentation ability. Thus, there is a great need for a baker's yeast strain with higher tolerance to baking-associated stresses. Recently, we revealed a novel antioxidative mechanism in a laboratory yeast strain that is involved in stress-induced nitric oxide (NO synthesis from proline via proline oxidase Put1 and N-acetyltransferase Mpr1. We also found that expression of the proline-feedback inhibition-less sensitive mutant γ-glutamyl kinase (Pro1-I150T and the thermostable mutant Mpr1-F65L resulted in an enhanced fermentation ability of baker's yeast in bread dough after freeze-thaw stress and air-drying stress, respectively. However, baker's yeast strains with high fermentation ability under multiple baking-associated stresses have not yet been developed. Results We constructed a self-cloned diploid baker's yeast strain with enhanced proline and NO synthesis by expressing Pro1-I150T and Mpr1-F65L in the presence of functional Put1. The engineered strain increased the intracellular NO level in response to air-drying stress, and the strain was tolerant not only to oxidative stress but also to both air-drying and freeze-thaw stresses probably due to the reduced intracellular ROS level. We also showed that the resultant strain retained higher leavening activity in bread dough after air-drying and freeze-thaw stress than that of the wild-type strain. On the other hand, enhanced stress tolerance and fermentation ability did not occur in the put1-deficient strain. This result suggests that NO is synthesized in baker's yeast from proline in response to oxidative stresses that induce ROS

  16. Enhancement of the proline and nitric oxide synthetic pathway improves fermentation ability under multiple baking-associated stress conditions in industrial baker's yeast.

    Science.gov (United States)

    Sasano, Yu; Haitani, Yutaka; Hashida, Keisuke; Ohtsu, Iwao; Shima, Jun; Takagi, Hiroshi

    2012-04-01

    During the bread-making process, industrial baker's yeast, mostly Saccharomyces cerevisiae, is exposed to baking-associated stresses, such as air-drying and freeze-thaw stress. These baking-associated stresses exert severe injury to yeast cells, mainly due to the generation of reactive oxygen species (ROS), leading to cell death and reduced fermentation ability. Thus, there is a great need for a baker's yeast strain with higher tolerance to baking-associated stresses. Recently, we revealed a novel antioxidative mechanism in a laboratory yeast strain that is involved in stress-induced nitric oxide (NO) synthesis from proline via proline oxidase Put1 and N-acetyltransferase Mpr1. We also found that expression of the proline-feedback inhibition-less sensitive mutant γ-glutamyl kinase (Pro1-I150T) and the thermostable mutant Mpr1-F65L resulted in an enhanced fermentation ability of baker's yeast in bread dough after freeze-thaw stress and air-drying stress, respectively. However, baker's yeast strains with high fermentation ability under multiple baking-associated stresses have not yet been developed. We constructed a self-cloned diploid baker's yeast strain with enhanced proline and NO synthesis by expressing Pro1-I150T and Mpr1-F65L in the presence of functional Put1. The engineered strain increased the intracellular NO level in response to air-drying stress, and the strain was tolerant not only to oxidative stress but also to both air-drying and freeze-thaw stresses probably due to the reduced intracellular ROS level. We also showed that the resultant strain retained higher leavening activity in bread dough after air-drying and freeze-thaw stress than that of the wild-type strain. On the other hand, enhanced stress tolerance and fermentation ability did not occur in the put1-deficient strain. This result suggests that NO is synthesized in baker's yeast from proline in response to oxidative stresses that induce ROS generation and that increased NO plays an important

  17. Enhancement of the proline and nitric oxide synthetic pathway improves fermentation ability under multiple baking-associated stress conditions in industrial baker's yeast

    Science.gov (United States)

    2012-01-01

    Background During the bread-making process, industrial baker's yeast, mostly Saccharomyces cerevisiae, is exposed to baking-associated stresses, such as air-drying and freeze-thaw stress. These baking-associated stresses exert severe injury to yeast cells, mainly due to the generation of reactive oxygen species (ROS), leading to cell death and reduced fermentation ability. Thus, there is a great need for a baker's yeast strain with higher tolerance to baking-associated stresses. Recently, we revealed a novel antioxidative mechanism in a laboratory yeast strain that is involved in stress-induced nitric oxide (NO) synthesis from proline via proline oxidase Put1 and N-acetyltransferase Mpr1. We also found that expression of the proline-feedback inhibition-less sensitive mutant γ-glutamyl kinase (Pro1-I150T) and the thermostable mutant Mpr1-F65L resulted in an enhanced fermentation ability of baker's yeast in bread dough after freeze-thaw stress and air-drying stress, respectively. However, baker's yeast strains with high fermentation ability under multiple baking-associated stresses have not yet been developed. Results We constructed a self-cloned diploid baker's yeast strain with enhanced proline and NO synthesis by expressing Pro1-I150T and Mpr1-F65L in the presence of functional Put1. The engineered strain increased the intracellular NO level in response to air-drying stress, and the strain was tolerant not only to oxidative stress but also to both air-drying and freeze-thaw stresses probably due to the reduced intracellular ROS level. We also showed that the resultant strain retained higher leavening activity in bread dough after air-drying and freeze-thaw stress than that of the wild-type strain. On the other hand, enhanced stress tolerance and fermentation ability did not occur in the put1-deficient strain. This result suggests that NO is synthesized in baker's yeast from proline in response to oxidative stresses that induce ROS generation and that increased NO

  18. Intermolecular hydrogen transfer catalyzed by a flavodehydrogenase, bakers' yeast flavocytochrome b2

    International Nuclear Information System (INIS)

    Urban, P.; Lederer, F.

    1985-01-01

    Bakers yeast flavocytochrome b2 is a flavin-dependent L-2-hydroxy acid dehydrogenase which also exhibits transhydrogenase activity. When a reaction takes place between [2- 3 H]lactate and a halogenopyruvate, tritium is found in water and at the halogenolactate C2 position. When the halogenopyruvate undergoes halide ion elimination, tritium is also found at the C3 position of the resulting pyruvate. The amount tau of this intermolecular tritium transfer depends on the initial keto acid-acceptor concentration. At infinite acceptor concentration, extrapolation yields a maximal transfer of 97 +/- 11%. This indicates that the hydroxy acid-derived hydrogen resides transiently on enzyme monoprotic heteroatoms and that exchange with bulk solvent occurs only at the level of free reduced enzyme. Using a minimal kinetic scheme, the rate constant for hydrogen exchange between Ered and solvent is calculated to be on the order of 10(2) M-1 S-1, which leads to an estimated pK approximately equal to 15 for the ionization of the substrate-derived proton while on the enzyme. It is suggested that this hydrogen could be shared between the active site base and Flred N5 anion. It is furthermore shown that some tritium is incorporated into the products when the transhydrogenation is carried out in tritiated water. Finally, with [2-2H]lactate-reduced enzyme, a deuterium isotope effect is observed on the rate of bromopyruvate disappearance. Extrapolation to infinite bromopyruvate concentration yields DV = 4.4. An apparent inverse isotope effect is determined for bromide ion elimination. These results strengthen the idea that oxidoreduction and elimination pathways involve a common carbanionic intermediate

  19. Reduções enantiosseletivas de cetonas utilizando-se fermento de pão Enantioselective reductions of ketones using baker's yeast

    Directory of Open Access Journals (Sweden)

    José Augusto R. Rodrigues

    2001-12-01

    Full Text Available Baker's yeast has been successful employed to reduce carbonyl compounds carrying appropriated substituents at distances under the electronic influence of the keto group. High yields and enantiomeric excess (ee were obtained with 1,2-alkanedione, 1,2-alkanedione (2-O-methyloxime and 1,3-alkanedione. Potential chiral building blocks were obtained and applied for stereoselective synthesis of valuable compounds. Evidence for a free radical chain process was obtained with baker's yeast reduction of a-iodoacetophenone using radical inhibitors.

  20. Ethanol yield and volatile compound content in fermentation of agave must by Kluyveromyces marxianus UMPe-1 comparing with Saccharomyces cerevisiae baker's yeast used in tequila production.

    Science.gov (United States)

    López-Alvarez, Arnoldo; Díaz-Pérez, Alma Laura; Sosa-Aguirre, Carlos; Macías-Rodríguez, Lourdes; Campos-García, Jesús

    2012-05-01

    In tequila production, fermentation is an important step. Fermentation determines the ethanol productivity and organoleptic properties of the beverage. In this study, a yeast isolated from native residual agave must was identified as Kluyveromyces marxianus UMPe-1 by 26S rRNA sequencing. This yeast was compared with the baker's yeast Saccharomyces cerevisiae Pan1. Our findings demonstrate that the UMPe-1 yeast was able to support the sugar content of agave must and glucose up to 22% (w/v) and tolerated 10% (v/v) ethanol concentration in the medium with 50% cells survival. Pilot and industrial fermentation of agave must tests showed that the K. marxianus UMPe-1 yeast produced ethanol with yields of 94% and 96% with respect to fermentable sugar content (glucose and fructose, constituting 98%). The S. cerevisiae Pan1 baker's yeast, however, which is commonly used in some tequila factories, showed 76% and 70% yield. At the industrial level, UMPe-1 yeast shows a maximum velocity of fermentable sugar consumption of 2.27g·L(-1)·h(-1) and ethanol production of 1.38g·L(-1)·h(-1), providing 58.78g ethanol·L(-1) at 72h fermentation, which corresponds to 96% yield. In addition, the major and minor volatile compounds in the tequila beverage obtained from UMPe-1 yeast were increased. Importantly, 29 volatile compounds were identified, while the beverage obtained from Pan1-yeast contained fewer compounds and in lower concentrations. The results suggest that the K. marxianus UMPe-1 is a suitable yeast for agave must fermentation, showing high ethanol productivity and increased volatile compound content comparing with a S. cerevisiae baker's yeast used in tequila production. Copyright © 2012 The Society for Biotechnology, Japan. Published by Elsevier B.V. All rights reserved.

  1. In vivo evaluation of antipyretic effects of homoeopathic ultrahigh dilutions of Typhoidinum on baker's yeast-induced fever in comparison with Paracetamol

    Directory of Open Access Journals (Sweden)

    Saeed Ahmad

    2017-01-01

    Full Text Available Introduction: Homoeopathy is a widely used, controversial alternative system of medicine. It is assumed that homoeopathic medicines are slower in action and does not work in acute conditions such as ‘fever’. The study aims to estimate the effectiveness of some homoeopathic remedies in fever and to compare their effects with Paracetamol. Materials and Methods: Baker's yeast fever model of rabbits was used in the study. Rabbits were divided into four different groups (n = 6. Rectal temperature was measured before and after fever induction hourly. After fever induction, medicines were administered orally. Paracetamol and Typhoidinum in 200C and 1M potencies were given orally. ANOVA followed by post hoc test was used for statistical analysis of results. The results were considered statistically significant at P ≤ 0.05. Results: Fever was induced in all the rabbits after 4 h of baker's yeast administration. The results of the study revealed the significant effectiveness of Typhoidinum in 200C and 1M potencies in baker's yeast-induced fever (P = 0.05. Typhoidinum in both potencies showed less significant results as compared to Paracetamol. However, all the medicines’ effects were significant compared to the negative control. Conclusion: Typhoidinum 200C and 1M worked against baker's yeast-induced fever. However, the results were slower and less significant than Paracetamol that might be due to lack of similarity of remedy picture and disease picture.

  2. p-Toluenethiol as an Initiator of Autolysis in Bakers' Yeast

    Science.gov (United States)

    Arnold, Wilfred N.

    1972-01-01

    Cysteine or dithiothreitol enhances the rate of autolysis in toluene-treated yeast. p-Toluenethiol alone is even more effective and is recommended for the isolation of β-fructofuranosidase. This suggests a more general application of p-toluenethiol in the isolation of enzymes from yeast. PMID:5058457

  3. Baker's yeast beta glucan supplementation increases salivary IgA and decreases cold/flu symptomatic days after intense exercise.

    Science.gov (United States)

    McFarlin, Brian K; Carpenter, Katie C; Davidson, Tiffany; McFarlin, Meredith A

    2013-09-01

    Strenuous exercise, such as running a marathon, is known to suppress mucosal immunity for up to 24 hr, which can increase the risk of developing an upper respiratory tract infection (URTI) and reduced performance capacity (Allgrove JE, Geneen L, Latif S, Gleeson M. Influence of a fed or fasted state on the s-IgA response to prolonged cycling in active men and women. Int J Sport Nutr Exerc Metab. 2009;19(3):209-221; Barrett B, Locken K, Maberry R, Schwamman J, Brown R, Bobula J, Stauffacher EA. The Wisconsin Upper Respiratory Symptom Survey (WURSS): a new research instrument for assessing the common cold. J Fam Pract. 2002;51(3):265; Carpenter KC, Breslin WL, Davidson T, Adams A, McFarlin BK. Baker's yeast beta glucan supplementation increases monocytes and cytokines post-exercise: implications for infection risk? Br J Nutr. 2012;1-9). While many dietary interventions have been used to combat postexercise immune suppression, most have been ineffective. The key purpose of this study was to determine if baker's yeast β-glucan (BG) could positively affect the immune system of individuals undergoing intense exercise stress using two experiments. In the first (E1; N = 182 men and women), BG was compared to placebo supplementation for the incidence of URTI symptoms for 28 days postmarathon. In the second (E2; N = 60 men and women) changes in salivary immunoglobulin A (IgA) were evaluated after 50-min of strenuous cycling when participants had been supplemented for 10 days with either BG (250 mg/day) or placebo (rice flour). For E1, subjects reported URTI symptoms using a daily health log. For E2, saliva was collected prior to, immediately, and 2-hr postexercise using a salivette. Data for E1 and E2 were analyzed using separate analyses of variance (ANOVAs) with repeated measures (p flu symptom days postmarathon compared to placebo (p = .026). In E2, BG was associated with a 32% increase in salivary IgA (p = .048) at 2 hr after exercise compared to placebo. In summary

  4. Some Practical Aspects of Sugar Fermentation by Baker's Yeast (Saccharomyces cerevisiae)

    Science.gov (United States)

    Freeland, P. W.

    1973-01-01

    Describes simple quantitative determinations for ethanol and carbon dioxide, together with techniques for examining the effects of a number of environmental factors on their production. The experimental work centers around the growth of a cell population of yeast, and is suitable for senior high school students. (JR)

  5. Teaching Microbial Physiology Using Glucose Repression Phenomenon in Baker's Yeast as an Example

    Science.gov (United States)

    Raghevendran, Vijayendran; Nielsen, Jens; Olsson, Lisbeth

    2005-01-01

    The yeast "Saccharomyces cerevisiae" has been used by human beings since ancient times for its ability to convert sugar to alcohol. Continual exposure to glucose in the natural environment for innumerable generations has probably enabled "S. cerevisiae" to grow in fermentative mode on sugars by switching off the genes responsible for respiration…

  6. Teaching microbial physiology using glucose repression phenomenon in baker's yeast as an examplele

    DEFF Research Database (Denmark)

    Vijayendran, Raghavendran; Nielsen, Jens; Olsson, Lisbeth

    2005-01-01

    The yeast Saccharomyces cerevisiae has been used by human beings since ancient times for its ability to convert sugar to alcohol. Continual exposure to glucose in the natural environment for innumerable generations has probably enabled S. cerevisiae to grow in fermentative mode on sugars by switc......The yeast Saccharomyces cerevisiae has been used by human beings since ancient times for its ability to convert sugar to alcohol. Continual exposure to glucose in the natural environment for innumerable generations has probably enabled S. cerevisiae to grow in fermentative mode on sugars...... by switching off the genes responsible for respiration even under aerobic conditions. This phenomenon is referred to as the Crabtree effect. The present review focuses on glucose repression in S. cerevisiae from a physiological perspective. Physiological studies presented involve batch and chemostat...

  7. mlh3 mutations in baker's yeast alter meiotic recombination outcomes by increasing noncrossover events genome-wide.

    Directory of Open Access Journals (Sweden)

    Najla Al-Sweel

    2017-08-01

    Full Text Available Mlh1-Mlh3 is an endonuclease hypothesized to act in meiosis to resolve double Holliday junctions into crossovers. It also plays a minor role in eukaryotic DNA mismatch repair (MMR. To understand how Mlh1-Mlh3 functions in both meiosis and MMR, we analyzed in baker's yeast 60 new mlh3 alleles. Five alleles specifically disrupted MMR, whereas one (mlh3-32 specifically disrupted meiotic crossing over. Mlh1-mlh3 representatives for each class were purified and characterized. Both Mlh1-mlh3-32 (MMR+, crossover- and Mlh1-mlh3-45 (MMR-, crossover+ displayed wild-type endonuclease activities in vitro. Msh2-Msh3, an MSH complex that acts with Mlh1-Mlh3 in MMR, stimulated the endonuclease activity of Mlh1-mlh3-32 but not Mlh1-mlh3-45, suggesting that Mlh1-mlh3-45 is defective in MSH interactions. Whole genome recombination maps were constructed for wild-type and MMR+ crossover-, MMR- crossover+, endonuclease defective and null mlh3 mutants in an S288c/YJM789 hybrid background. Compared to wild-type, all of the mlh3 mutants showed increases in the number of noncrossover events, consistent with recombination intermediates being resolved through alternative recombination pathways. Our observations provide a structure-function map for Mlh3 that reveals the importance of protein-protein interactions in regulating Mlh1-Mlh3's enzymatic activity. They also illustrate how defective meiotic components can alter the fate of meiotic recombination intermediates, providing new insights for how meiotic recombination pathways are regulated.

  8. Dowex anion exchanger-loaded-baker's yeast as bi-functionalized biosorbents for selective extraction of anionic and cationic mercury(II) species

    International Nuclear Information System (INIS)

    Mahmoud, Mohamed E.; Yakout, Amr A.; Osman, Maher M.

    2009-01-01

    Dowex anion exchanger-immobilized-baker's yeast [Dae-yeast] were synthesized and potentially applied as environmental friendly biosorbents to evaluate the up-take process of anionic and cationic mercury(II) species as well as other metal ions. Optimization of mass ratio of Dowex anion exchanger versus yeast (1:1-1:10) in presence of various interacting buffer solutions (pH 4.0-9.0) was performed and evaluated. Surface modification of [Dae-yeast] was characterized by scanning electron microscopy (SEM) and infrared spectroscopy. The maximum metal biosorption capacity values of [Dae-yeast] towards mercury(II) were found in the range of 0.800-0.960, 0.840-0.950 and 0.730-0.900 mmol g -1 in presence of buffer solutions pH 2.0, 4.0 and 7.0, respectively. Three possible and different mechanisms are proposed to account for the biosorption of mercury and mercuric species under these three buffering conditions based on ion exchange, ion pair and chelation interaction processes. Factors affecting biosorption of mercury from aqueous medium including the pH effect of aqueous solutions (1.0-7.0), shaking time (1-30 min) and interfering ions were searched. The potential applications of modified biosorbents for selective biosorption and extraction of mercury from different real matrices including dental filling waste materials, industrial waste water samples and mercury lamp waste materials were also explored. The results denote to excellent percentage extraction values, from nitric acid as the dissolution solvent with a pH 2.0, as determined in the range of 90.77-97.91 ± 3.00-5.00%, 90.00-93.40 ± 4.00-5.00% and 92.31-100.00 ± 3.00-4.00% for the three tested samples, respectively.

  9. Chemoselective biohydrogenation of chalcone (2Ε)-3-(1,3-benzodioxole-5-yl)-1-phenyl-2-propen-1-one mediated by baker yeasts immobilized in polymeric supports

    International Nuclear Information System (INIS)

    Mundstock, Flavia L.S.; Silva, Vanessa D.; Nascimento, Maria da G.

    2009-01-01

    In this study, the yeast Saccharomyces cerevisiae, baker's yeast (BY) was immobilized in poly(ethylene oxide) (PEO), poly(vinyl alcohol) (PVA), sodium caseinate (SC), gelatin (G) films and in agar (A) and gelatin (G) gels, and used as a biocatalyst in the biohydrogenation reaction of (2Ε)-3-(1,3-benzodioxyl-5-yl)-1-phenyl-2-propen-1-one (1). The transformation of (1) into the corresponding dehydro chalcone (2) through biohydrogenation reactions was carried out in n-hexane at 25 or 35 deg C, for 4-48 h reaction. The product conversion, under different experimental conditions, was evaluated by hydrogen nuclear magnetic resonance, 1 H NMR.The highest conversion degrees were achieved using BY immobilized in agar gel, (29-47%), depending also on the temperature. Using BY immobilized in PEO, PVA, SC and G films, the conversion into (2) was lower (0-21%). The results show the feasibility of the use of BY immobilized in polymeric materials to reduce a,b-unsaturated carbonyl compounds. (author)

  10. Increased availability of NADH in metabolically engineered baker's yeast improves transaminase-oxidoreductase coupled asymmetric whole-cell bioconversion

    DEFF Research Database (Denmark)

    Knudsen, Jenny Dahl; Hägglöf, Cecilia; Weber, Nora

    2016-01-01

    yeast for transamination-reduction coupled asymmetric one-pot conversion was investigated. RESULTS: A series of active whole-cell biocatalysts were constructed by over-expressing the (S)-selective ω-transaminase (VAMT) from Capsicum chinense together with the NADH-dependent (S)-selective alcohol...

  11. Entropy of Baker's Transformation

    Institute of Scientific and Technical Information of China (English)

    栾长福

    2003-01-01

    Four theorems about four different kinds of entropies for Baker's transformation are presented. The Kolmogorov entropy of Baker's transformation is sensitive to the initial flips by the time. The topological entropy of Baker's transformation is found to be log k. The conditions for the state of Baker's transformation to be forbidden are also derived. The relations among the Shanonn, Kolmogorov, topological and Boltzmann entropies are discussed in details.

  12. Beyond bread and beer: whole cell protein extracts from baker's yeast as a bulk source for 3D cell culture matrices.

    Science.gov (United States)

    Bodenberger, Nicholas; Kubiczek, Dennis; Paul, Patrick; Preising, Nico; Weber, Lukas; Bosch, Ramona; Hausmann, Rudolf; Gottschalk, Kay-Eberhard; Rosenau, Frank

    2017-03-01

    Here, we present a novel approach to form hydrogels from yeast whole cell protein. Countless hydrogels are available for sophisticated research, but their fabrication is often difficult to reproduce, with the gels being complicated to handle or simply too expensive. The yeast hydrogels presented here are polymerized using a four-armed, amine reactive crosslinker and show a high chemical and thermal resistance. The free water content was determined by measuring swelling ratios for different protein concentrations, and in a freeze-drying approach, pore sizes of up to 100 μm in the gel could be created without destabilizing the 3D network. Elasticity was proofed to be adjustable with the help of atomic force microscopy by merely changing the amount of used protein. Furthermore, the material was tested for possible cell culture applications; diffusion rates in the network are high enough for sufficient supply of human breast cancer cells and adenocarcinomic human alveolar basal epithelial cells with nutrition, and cells showed high viabilities when tested for compatibility with the material. Furthermore, hydrogels could be functionalized with RGD peptide and the optimal concentration for sufficient cell adhesion was determined to be 150 μM. Given that yeast protein is one of the cheapest and easiest available protein sources and that hydrogels are extremely easy to handle, the developed material has highly promising potential for both sophisticated cell culture techniques as well as for larger scale industrial applications.

  13. Changes in trehalose content of baker's yeast as affected by octanoic acid Alterações no teor de trealose de levedura de panificação provocadas por ácido octanóico

    Directory of Open Access Journals (Sweden)

    L.E. Gutierrez

    1993-12-01

    Full Text Available Octanoic acid inhibited ethanolic fermentation by Saccharomyces cerevisiae (bakers yeast and the trehalose accumulation, however did not affect the endogenous degradation of trehalose. This inhibition may be explained by the binding of octanoic acid to hexokinase or other proteins of plasma membrane because they are not necessary for endogenous fermentation. The degradation of trehalose may be due to an activation of trehalase.A adição de ácido octanóico inibiu a fermentação alcoólica realizada por Saccharomyces cerevisiae (levedura de panificação e o acúmulo de trealose, contudo não afetou a degradação endógena de trealose. Esta inibição poderia ser explicada pela ligação do ácido octanóico a hexoquinase ou outra proteína da membrana plasmática porque não são necessárias para a fermentação endógena. A degradação da trealose poderia ser devida a uma ativação da trealase.

  14. Fed-batch cultivation of baker's yeast followed by nitrogen or carbon starvation: effects on fermentative capacity and content of trehalose and glycogen

    DEFF Research Database (Denmark)

    Jørgensen, Henning; Olsson, Lisbeth; Rønnow, B.

    2002-01-01

    , trehalose and glycogen. Nitrogen starvation triggered the accumulation of trehalose and glycogen. After 8 h of starvation, the content of trehalose and glycogen was increased 4-fold and 2-fold, respectively. Carbon starvation resulted in a partial conversion of glycogen into trehalose. The trehalose content...... increased from 45 to 64 mg (g dry-weight)(-1), whereas the glycogen content in the same period was reduced from 55 to 5 mg (g dry-weight)(-1). Glycogen was consumed faster than trehalose during storage of the starved yeast for 1 month. Nitrogen starvation resulted in a decrease in the protein content...

  15. Overexpression of O‐methyltransferase leads to improved vanillin production in baker's yeast only when complemented with model‐guided network engineering

    DEFF Research Database (Denmark)

    Brochado, Ana Rita; Patil, Kiran R.

    2013-01-01

    limited in eukaryotic systems. In this study, we compared the effects of overexpressing a key gene in de novo vanillin biosynthesis (coding for O‐methyltransferase, hsOMT) in two yeast strains, with and without model‐guided global network modifications. Overexpression of hsOMT resulted in increased...... vanillin production only in the strain with model‐guided modifications, exemplifying advantage of using a global strategy prior to local pathway manipulation. Biotechnol. Bioeng. 2013; 110: 656–659. © 2012 Wiley Periodicals, Inc....

  16. Overexpression of O-methyltransferase leads to improved vanillin production in baker's yeast only when complemented with model-guided network engineering.

    Science.gov (United States)

    Brochado, Ana Rita; Patil, Kiran R

    2013-02-01

    Overproduction of a desired metabolite is often achieved via manipulation of the pathway directly leading to the product or through engineering of distant nodes within the metabolic network. Empirical examples illustrating the combined effect of these local and global strategies have been so far limited in eukaryotic systems. In this study, we compared the effects of overexpressing a key gene in de novo vanillin biosynthesis (coding for O-methyltransferase, hsOMT) in two yeast strains, with and without model-guided global network modifications. Overexpression of hsOMT resulted in increased vanillin production only in the strain with model-guided modifications, exemplifying advantage of using a global strategy prior to local pathway manipulation. Copyright © 2012 Wiley Periodicals, Inc.

  17. Activation of waste brewer's yeast Saccharomyces cerevisiae for bread production

    OpenAIRE

    Popov Stevan D.; Dodić Siniša N.; Mastilović Jasna S.; Dodić Jelena M.; Popov-Raljić Jovanka V.

    2005-01-01

    The waste brewer's yeast S. cerevisiae (activated and non-activated) was compared with the commercial baker's yeast regarding the volume of developed gas in dough, volume and freshness stability of produced bread. The activation of waste brewer's yeast resulted in the increased volume of developed gas in dough by 100% compared to non-activated brewer's yeast, and the obtained bread is of more stable freshness compared to bread produced with baker's yeast. The activation of BY affects positive...

  18. Interview to Bobby Baker

    Directory of Open Access Journals (Sweden)

    Aisling Foster

    2015-11-01

    Full Text Available Bobby Baker es una mujer, y una artista londinense con una carrera que abarca casi cuatro décadas. Ha trabajado fundamentalmente en el ámbito de la performance haciendo frecuente uso de material personal. Entre sus obras encontramos una versión comestible de su familia a tamaño natural, una protesta callejera de guisantes humanos que reclaman los derechos de los pacientes en el ámbito de la salud mental o una serie de performances que de modo irónico representan su vida doméstica. Su exposición itinerante «Diary Drawings: Mental Illness and Me 1997 - 2008» se estrenó en la Wellcome Collection en 2009, y el libro que la acompaña fue galardonado con el Mind Book of the Year 2011. Sus obras más recientes Mad Gyms & Kitchens y Drawing On A (Grand Mother’s Experience han sido encargadas como parte de la Cultural Olympiad de Londres en 2012 y del Women of the World Festival en 2015 respectivamente. Bobby Baker recibió el Doctorado Honorífico en 2011 tras su participación en la AHRC Creative Fellowship de Queen Mary University de Londres y es la directora artística de la asociación Daily Life Ltd.http://dailylifeltd.co.uk Grabación y edición sonora: Andrea ZarzaTraducción y transcripción: Celia Terradillos, Zara Rodríguez 

  19. Chemoselective biohydrogenation of chalcone (2{Epsilon})-3-(1,3-benzodioxole-5-yl)-1-phenyl-2-propen-1-one mediated by baker yeasts immobilized in polymeric supports; Bioidrogenacao quimioseletiva da chalcona (2{Epsilon})-3-(1,3-benzodioxol-5-il)-1-fenil-2-propen-1-ona mediada por fermentos de pao imobilizado em suportes polimericos

    Energy Technology Data Exchange (ETDEWEB)

    Mundstock, Flavia L.S.; Silva, Vanessa D.; Nascimento, Maria da G., E-mail: mundstock@qmc.ufsc.b [Universidade Federal de Santa Catarina (DQ/UFSC), Florianopolis, SC (Brazil). Dept. de Quimica

    2009-07-01

    In this study, the yeast Saccharomyces cerevisiae, baker's yeast (BY) was immobilized in poly(ethylene oxide) (PEO), poly(vinyl alcohol) (PVA), sodium caseinate (SC), gelatin (G) films and in agar (A) and gelatin (G) gels, and used as a biocatalyst in the biohydrogenation reaction of (2{Epsilon})-3-(1,3-benzodioxyl-5-yl)-1-phenyl-2-propen-1-one (1). The transformation of (1) into the corresponding dehydro chalcone (2) through biohydrogenation reactions was carried out in n-hexane at 25 or 35 deg C, for 4-48 h reaction. The product conversion, under different experimental conditions, was evaluated by hydrogen nuclear magnetic resonance, {sup 1}H NMR.The highest conversion degrees were achieved using BY immobilized in agar gel, (29-47%), depending also on the temperature. Using BY immobilized in PEO, PVA, SC and G films, the conversion into (2) was lower (0-21%). The results show the feasibility of the use of BY immobilized in polymeric materials to reduce a,b-unsaturated carbonyl compounds. (author)

  20. Natural and modified promoters for tailored metabolic engineering of the yeast Saccharomyces cerevisiae

    NARCIS (Netherlands)

    Hubmann, Georg; Thevelein, Johan M; Nevoigt, Elke

    2014-01-01

    The ease of highly sophisticated genetic manipulations in the yeast Saccharomyces cerevisiae has initiated numerous initiatives towards development of metabolically engineered strains for novel applications beyond its traditional use in brewing, baking, and wine making. In fact, baker's yeast has

  1. The Baker's cyst - a diagnostic problem

    International Nuclear Information System (INIS)

    Meydam, K.

    1981-01-01

    Precise definition of Baker's cyst has been prevented by variety of synonyms. Following anatomical description, Baker's determination, and investigations of myself one should differentiate between the rupture of capsule, bursa semimembranos-gastrocnemia, and Baker's cyst because thea are clearly independent from the pathologic-anatomical point of view. Clinical importance of Baker's cyst in connection with further diseases of the knee joint and therapeutical possibilities are discussed. (orig.) [de

  2. Obituary: Dr. Richard Roland Baker

    Directory of Open Access Journals (Sweden)

    Thornton R

    2014-12-01

    Full Text Available Richard Baker died at Easter 2007 after a very short illness. It is sad that he died so soon after his retirement from the British American Tobacco Company at the end of 2005, and just as he was beginning to enjoy his new life, even though tobacco science still had a part to play.

  3. The manometric determination of thiamine pyrophosphate and the inhibition of the acid yeast phosphatase

    NARCIS (Netherlands)

    Steyn-Parvé, Elizabeth P.

    1962-01-01

    Sodium molybdate is a powerful inhibitor of the acid yeast phosphatase in both fresh baker's yeast and dried brewer's yeast, provided that the yeast is suspended in a suitable buffer. It displays no action in citrate or phosphate buffers, but is active in acetate or maleate buffers, both at the

  4. Baker's asthma in a child.

    Science.gov (United States)

    Alonso, E; Ausín, A; Elices, A; Moreno-Escobosa, M; Ibáñez, M; Laso, M

    2001-01-01

    baker's asthma is a well-known occupational lung disease which usually develops in adults. We report the case of a two years old boy who suffered from asthma, urticaria and atopic dermatitis for twelve months, whose symptoms were associated to visits to his grandfather's bakery. skin prick tests (SPT) were made to dust mites, moulds, flours, alfa-amylase and egg. It was also determined total IgE and specific IgE antibodies to alfa-amylase and flours. Subsequently, a challenge test was carried out with wheat flour. The SPTs were positive to flours, alfa-amylase and egg. The determination of specific IgE antibodies showed 2.64 kU/L to wheat, 0.79 kU/L to glyadin and 2.98 kU/L to alfa-amylase. The patient developed asthma and rhinitis after manipulating wheat flour for 10 min. we demonstrated a type I hypersensitivity to wheat flour and alfa-amylase in a two years old child by SPT, specific IgE antibodies and challenge test. This case in the childhood equivalent of occupational baker's asthma.

  5. Hybrid yeast strains capable of raising an extraordinarily broad range of dough types

    Energy Technology Data Exchange (ETDEWEB)

    Kowalski, S.; Zander, I.; Windisch, S.

    1981-01-01

    Over 200 hybrid yeast strains were screened and 11 of these found to have versatile fermentation characteristics. This paper reports the results obtained with these 11 strains compared with a commercially available strain of baker's yeast used for bread making and marketed as 'instant active dry yeast'. In contrast to bakers yeast, the hybrid strains fermented very well in yeast, hard biscuit, shortcake and heavy cake dough without prior sponge formation. The fermentation kinetics were investigated and the technical potential of such hybrid strains discussed on the basis of the fermentation kinetics.

  6. Pühendusega isadele - Baker Street

    Index Scriptorium Estoniae

    2009-01-01

    Üritusest 7. novembril Kuressaares Arensburg lounge-restoranis Muusa toimuvast isadepäevahõngulisest üritusest, esinevad Virgo Veldi & Band kavaga "Baker Street", erikülalisena Villu Veski. Saksofonistist Virgo Veldist

  7. CRED REA Algal Assessments, Baker Island 2006

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Twelve quadrats were sampled along 2 consecutively-placed, 25m transect lines as part of Rapid Ecological Assessments conducted at 8 sites at Baker Island in the US...

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

    Indian Academy of Sciences (India)

    poration, complexation, reverse osmosis and membrane pro- cesses [2–4]. ... activities and some human activities such as exploitation of uranium and ... bre adsorbent for U(VI) and Th(IV) removal from aqueous solutions. 2. Experimental ..... Adsorption capacity of uranium(VI) and thorium(IV) in binary systems. where. H.

  9. Some Aspects of Catalase Induction in Baker's Yeast (Saccharomyces cerevisiae)

    Science.gov (United States)

    Freeland, P. W.

    1974-01-01

    Described are experiments for demonstrating essential features of substrate-induced enzyme synthesis based on the Jacob-Monod model, and for showing that the activity of certain genes can be modified by environmental temperature. (RH)

  10. Magnetic resonance investigation of magnetic-labeled baker's yeast cells

    International Nuclear Information System (INIS)

    Godoy Morais, J.P.M.; Azevedo, R.B.; Silva, L.P.; Lacava, Z.G.M.; Bao, S.N.; Silva, O.; Pelegrini, F.; Gansau, C.; Buske, N.; Safarik, I.; Safarikova, M.; Morais, P.C.

    2004-01-01

    In this study, the interaction of DMSA-coated magnetite nanoparticles (5 and 10 nm core-size) with Saccharomyces cerevisae was investigated using magnetic resonance (MR) and transmission electron microscopy (TEM). The TEM micrographs revealed magnetite nanoparticles attached externally to the cell wall. The MR data support the strong interaction among the nanoparticles supported by the cells. A remarkable shift in the resonance field was used as signature of particle attachment to the cell wall

  11. The indentation of pressurized elastic shells: from polymeric capsules to yeast cells

    KAUST Repository

    Vella, D.; Ajdari, A.; Vaziri, A.; Boudaoud, A.

    2011-01-01

    of capsules. Our results are relevant for determining the internal pressure in bacterial, fungal or plant cells. As an illustration of this, we apply our results to recent measurements of the stiffness of baker's yeast and infer from these experiments

  12. Analysis of in vivo binding of yeast heat shock factor to promoter DNA

    African Journals Online (AJOL)

    SERVER

    2008-04-17

    Apr 17, 2008 ... The baker's yeast, Saccharomyces cerevisiae, harbors only a single HSF ... ethanol. The resulting DNA was dissolved in 20 µl TE. PCR. 3% of each .... tolerance oxidant stress, and involve in other biochemical pathways.

  13. 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

  14. Activation of waste brewer's yeast Saccharomyces cerevisiae for bread production

    Directory of Open Access Journals (Sweden)

    Popov Stevan D.

    2005-01-01

    Full Text Available The waste brewer's yeast S. cerevisiae (activated and non-activated was compared with the commercial baker's yeast regarding the volume of developed gas in dough, volume and freshness stability of produced bread. The activation of waste brewer's yeast resulted in the increased volume of developed gas in dough by 100% compared to non-activated brewer's yeast, and the obtained bread is of more stable freshness compared to bread produced with baker's yeast. The activation of BY affects positively the quality of produced bread regarding bread volume. The volume of developed gas in dough prepared with the use of non-activated BY was not sufficient, therefore, it should not be used as fermentation agent, but only as an additive in bread production process for bread freshness preservation. Intense mixing of dough results in more compressible crumb 48 hrs after baking compared to high-speed mixing.

  15. Steroids isolated from Millettia versicolor Baker (Fabaceae)

    African Journals Online (AJOL)

    STORAGESEVER

    2008-06-03

    Jun 3, 2008 ... African Journal of Biotechnology Vol. 7 (11), pp. ... Full Length Research Paper ... of Millettia versicolor Baker, a medicinal plant used in the traditional ... The spectral analysis enabled us to identify 4 known .... evidence for participation of protein kinase C and protein kinase A ... Neoplasma 51(6): 407-414.

  16. Procces for producing ethanol and/or baking yeast. Verfahren zur Herstellung von Aethanol und/oder Backhefe

    Energy Technology Data Exchange (ETDEWEB)

    Pilepp, E.; Scheffler, U.; Osthaus, G.

    1987-06-25

    A method for the production of ethanol and/or baker's yeast is described, in which a substrate of sacchariferous substances and a nutrient solution is fermented with a yeast of the genus saccharomyces at a temperature of 20 to 40/sup 0/C and ethanol and/or the baker's yeast are subsequently separated from the fermented substrate. This method provides that the mixture consisting of the substrate and the yeast is sterilized by circulation in a homogenizer.

  17. Water-quality effects on Baker Lake of recent volcanic activity at Mount Baker, Washington

    Science.gov (United States)

    Bortleson, Gilbert Carl; Wilson, Reed T.; Foxworthy, B.L.

    1976-01-01

    Increased volcanic activity on Mount Baker, which began in March 1975, represents the greatest known activity of a Cascade Range volcano since eruptions at Lassen Peak, Calif. during 1914-17. Emissions of dust and increased emanations of steam, other gases, and heat from the Sherman Crater area of the mountain focused attention on the possibility of hazardous events, including lava flows, pyroclastic eruptions, avalanches, and mudflows. However, the greatest undesirable natural results that have been observed after one year of the increased activity are an increase in local atmospheric pollution and a decrease in the quality of some local water resources, including Baker Lake. Baker Lake, a hydropower reservoir behind Upper Baker Dam, supports a valuable fishery resource and also is used for recreation. The lake's feedwater is from Baker River and many smaller streams, some of which, like Boulder Creek, drain parts of Mount Baker. Boulder Creek receives water from Sherman Crater, and its channel is a likely route for avalanches or mudflows that might originate in the crater area. Boulder Creek drains only about 5 percent of the total drainage area of Baker Lake, but during 1975 carried sizeable but variable loads of acid and dissolved minerals into the lake. Sulfurous gases and the fumarole dust from Sherman Crater are the main sources for these materials, which are brought into upper Boulder Creek by meltwater from the crater. In September 1973, before the increased volcanic activity, Boulder Creek near the lake had a pH of 6.0-6.6; after the increase the pH ranged as low as about 3.5. Most nearby streams had pH values near 7. On April 29, in Boulder Creek the dissolved sulfate concentration was 6 to 29 times greater than in nearby creeks or in Baker River; total iron was 18-53 times greater than in nearby creeks; and other major dissolved constituents generally 2 to 7 times greater than in the other streams. The short-term effects on Baker Lake of the acidic

  18. Reduction of toxic effects of aflatoxin B1 by using baker yeast (Saccharomyces cerevisiae in growing broiler chicks diets Redução dos efeitos tóxicos da aflatoxina B1, utilizando-se levedura de panificação (Saccharomyces cerevisiae, na dieta de pintos de corte em crescimento

    Directory of Open Access Journals (Sweden)

    Kemal Çelýk

    2003-06-01

    Full Text Available This study was carried out to investigate the effects of adding baker yeast (BY, chlortetracycline (CTC and both BY + CTC to a control diet containing 200 ng/g of aflatoxin B1 (C + AFB1 on performance, serum parameters and pathologyc alterations of broilers. A total 100 chicks (Ross PM 3 were divided into five groups in individual cages and each containing 20 animals. BY, a rich source of protein and vitamin B complex, was mixed into the diets at 2.0 %, CTC was mixed into the diet at 2.5 ng/g. Feed consumption, body weight and feed efficiency were recorded weekly. Serum parameters and pathologyc alterations were determined at the end of the study. Dead animals were recorded daily. Liver changes were clearly apparent in the C+AFB1and C+ AFB1+CTC most of the livers were enlarged, yellow and had pethecial hemorrhages. Canalicula cholestosis was absent in group C+AFB1 and C+ AFB1+CTC, but not others. When compared to the control (C group, alkaline phosphatase (ALP, appear to be significantly increased in the C+AFB1 and C+CTC+ AFB1 groups. Serum glutamic oxalacetic transaminase (GOTwas increased in C+AFB1 birds. Serum alphaphetoprotein was not affected by the treatments. Feed consumption and body weight were significantly reduced in group AFB1. Birds receiving BY + AFB1, CTC + AFB1 and BY + CTC + AFB1 had a significantly higher body weight than group C+AFB1. Feed efficiency was better in group CTC + AFB1 than the others. The findings of this research suggest tha BY (2% can partly counteract some of the toxic effects of AFB1.Este estudo foi desenvolvido para avaliar os efeitos da adição de Levedura de panificação (BY e cortetraciclina (CTC e ambos BY+CTC a uma dieta controle © contendo 200 ng/g de aflatoxina B1 (C+AFB1 sobre desempenho, parâmetros séricos e alterações patológicas de frangos de corte. Um total de 100 pintinhos (Ross PM3 foi dividido em cinco grupos, em gaiolas individuais, contendo 20 animais para cada grupo. A levedura de

  19. Between science and industry-applied yeast research.

    Science.gov (United States)

    Korhola, Matti

    2018-03-01

    I was fortunate to enter yeast research at the Alko Research Laboratories with a strong tradition in yeast biochemistry and physiology studies. At the same time in the 1980s there was a fundamental or paradigm change in molecular biology research with discoveries in DNA sequencing and other analytical and physical techniques for studying macromolecules and cells. Since that time biotechnological research has expanded the traditional fermentation industries to efficient production of industrial and other enzymes and specialty chemicals. Our efforts were directed towards improving the industrial production organisms: minerals enriched yeasts (Se, Cr, Zn) and high glutathione content yeast, baker´s, distiller´s, sour dough and wine yeasts, and the fungal Trichoderma reesei platform for enzyme production. I am grateful for the trust of my colleagues in several leadership positions at the Alko Research Laboratories, Yeast Industry Platform and at the international yeast community.

  20. Obituary: James Gilbert Baker, 1914-2005

    Science.gov (United States)

    Baker, Neal Kenton

    2005-12-01

    Dr. James Gilbert Baker, renowned astronomer and optical physicist, died 29 June 2005 at his home in Bedford, New Hampshire at the age of 90. Although his scientific interest was astronomy, his extraordinary ability in optical design led to the creation of hundreds of optical systems that supported astronomy, aerial reconnaissance, instant photography (Polaroid SX70 camera), and the US space programs. He was the recipient of numerous awards for his creative work. He was born in Louisville, Kentucky, on 11 November 1914, the fourth child of Jesse B. Baker and Hattie M. Stallard. After graduating from Louisville DuPont Manual High, he went on to attend the University of Louisville majoring in Mathematics. He became very close to an Astronomy Professor, Dr. Moore, and many times used his telescopes to do nightly observations. While at the university, he built mirrors for his own telescopes and helped form the Louisville Astronomical Society in 1933. At the University of Louisville, he also met his future wife, Elizabeth Katherine Breitenstein of Jefferson County, Kentucky. He received his BA in 1935 at the height of the Depression. He began his graduate work in astronomy at the Harvard College Observatory. After his MA (1936), he was appointed a Junior Fellow (1937-1943) in the Prestigious Harvard Society of Fellows. He received his PhD in 1942 from Harvard in rather an unusual fashion, which is worth retelling. During an Astronomy Department dinner, Dr. Harlow Shapley (the director) asked him to give a talk. According to the "Courier-Journal Magazine", "Dr. Shapley stood up and proclaimed an on-the-spot departmental meeting and asked for a vote on recommending Baker for a Ph.D. on the basis of the 'oral exam' he had just finished. The vote was unanimous." It was at Harvard College Observatory during this first stage of his career that he collaborated with Donald H. Menzel, Lawrence H. Aller, and George H. Shortley on a landmark set of papers on the physical processes

  1. Assessment and characterisation of yeast-based products intended to mitigate ochratoxin exposure using in vitro and in vivo models

    NARCIS (Netherlands)

    Pfohl-Leszkowicz, A; Hadjeba-Medjdoub, K; Ballet, N; Schrickx, J; Fink-Gremmels, J

    2015-01-01

    The aim of this paper was to evaluate the capacity of several yeast-based products, derived from baker's and brewer's yeasts, to sequester the mycotoxin ochratoxin A (OTA) and to decrease its rate of absorption and DNA adduct formation in vivo. The experimental protocol included in vitro binding

  2. 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.

  3. Conditions of activation of yeast plasma membrane ATPase.

    Science.gov (United States)

    Sychrová, H; Kotyk, A

    1985-04-08

    The in vivo activation of the H+-ATPase of baker's yeast plasma membrane found by Serrano in 1983 was demonstrated with D-glucose aerobically and anaerobically (as well as in a respiration-deficient mutant) and, after suitable induction, with maltose, trehalose, and galactose. The activated but not the control ATPase was sensitive to oligomycin. No activation was possible in a cell-free extract with added glucose. The ATPase was not activated in yeast protoplasts which may account for the absence of glucose-stimulated secondary active transports in these wall-less cells and provide support for a microscopic coupling between ATPase activity and these transports in yeast cells.

  4. Yeasts: providing questions and answers for modern biology.

    Science.gov (United States)

    Dickinson, J R

    2000-01-01

    Yeasts are to be found in virtually every conceivable niche on this planet and are amazingly varied in their shapes ('morphologies'), life cycles, metabolic capabilities, potentials for use in industrial processes, abilities to spoil food and drink or to act as dangerous human pathogens. This review describes four very different species of yeast to illustrate some of the diversity which exists and, in the case of one of them, Saccharomyces cerevisiae (the familiar baker's or brewer's yeast), the extent of both our knowledge and ignorance.

  5. Prevalence of sensitization to 'improver' enzymes in UK supermarket bakers.

    Science.gov (United States)

    Jones, M; Welch, J; Turvey, J; Cannon, J; Clark, P; Szram, J; Cullinan, P

    2016-07-01

    Supermarket bakers are exposed not only to flour and alpha-amylase but also to other 'improver' enzymes, the nature of which is usually shrouded by commercial sensitivity. We aimed to determine the prevalence of sensitization to 'improver' enzymes in UK supermarket bakers. We examined the prevalence of sensitization to enzymes in 300 bakers, employed by one of two large supermarket bakeries, who had declared work-related respiratory symptoms during routine health surveillance. Sensitization was determined using radioallergosorbent assay to eight individual enzymes contained in the specific 'improver' mix used by each supermarket. The prevalence of sensitization to 'improver' enzymes ranged from 5% to 15%. Sensitization was far more likely if the baker was sensitized also to either flour or alpha-amylase. The prevalence of sensitization to an 'improver' enzyme did not appear to be related to the concentration of that enzyme in the mix. We report substantial rates of sensitization to enzymes other than alpha-amylase in UK supermarket bakers; in only a small proportion of bakers was there evidence of sensitization to 'improver mix' enzymes without sensitization to either alpha-amylase or flour. The clinical significance of these findings needs further investigation, but our findings indicate that specific sensitization in symptomatic bakers may not be identified without consideration of a wide range of workplace antigens. © 2016 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  6. Phenolics from Kalanchoe marmorata Baker, Family Crassulaceae

    Directory of Open Access Journals (Sweden)

    Abdel Nasser Badawy Singab

    2011-06-01

    Full Text Available In search of plants rich in phenolics in Egypt, Kalanchoe marmorata Baker was subjected to phytochemical study. The preliminary phytochemical screening revealed its richness in phenolics. Fractionation of the lyophilized aqueous extract of the leaves of K. marmorata by different organic solvents successively resulted in the isolation and purification of five compounds from the ethyl acetate soluble fraction. These compounds namely; E1 isorhamnetin-3-O-α-l-1C4-rhamnopyranoside; E2 quercitin; E3 4′-methoxy-myricetin-3-O-α-l-1C4-rhamnopyranoside; E4 Quercitin-3-O-β-d-4C1-glucopyranoside and E5 protocatechuic-4′-O-β-d-4C1-glucopyranoside, were identified by analysis of their spectral data including 1H NMR and 13C NMR.

  7. 78 FR 27215 - Baker County Oregon; Notice of Application Tendered for Filing With the Commission and...

    Science.gov (United States)

    2013-05-09

    ...: Baker County, Oregon (Baker County). e. Name of Project: Mason Dam Hydroelectric Project. f. Location...'s (Reclamation) Mason Dam, near Baker City, in Baker County, Oregon. The project would occupy 6.4... facilities. The proposed project's generation would not change the current day- to-day operation of Mason dam...

  8. Posterior tibial neuropathy by a Baker's cyst: case report.

    Science.gov (United States)

    Lee, J H; Jun, J B; Lee, H S; Yun, H R; Choi, C H; Park, S B; Hong, E K; Yoo, D H; Kim, S Y

    2000-01-01

    Baker's cysts are rare cause of peripheral nerve entrapment and only a few cases of tibial nerve entrapment resulting from the popliteal cyst in the calf muscle have been reported in the literature. We present a case of rheumatoid arthritis complicated by a Baker's cyst with a tibial nerve entrapment. It is important to diagnose a Baker's cyst early and to differentiate it from thrombophlebitis, a popliteal aneurysm, tumor or muscle tear to effect optimal therapy and to obviate a potential neuropathy. Prompt recognition of these cases may save the patients unnecessary procedures and delay in treatment.

  9. Disturbance and Celebration of Josephine Baker in Copenhagen 1928

    DEFF Research Database (Denmark)

    Spanger, Marlene

    2015-01-01

    Marlene Spanger analyses reactions to the internationally recognised dancer and singer Josephine Baker (1906–1975), whose performances in Copenhagen gave rise to a heated emotional debate in Danish newspapers; these reactions mirror contemporary dominant religious, biological and colonial discour...

  10. CRED REA Coral Population Parameters at Baker, Phoenix Islands, 2004

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Belt transects along 2 consecutively-placed, 25m transect lines were surveyed as part of Rapid Ecological Assessments conducted at 3 sites at Baker in the Phoenix...

  11. CRED REA Algal Assessments, Baker Island 2004 (NODC Accession 0010352)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Twelve quadrats were sampled along 2 consecutively-placed, 25m transect lines as part of Rapid Ecological Assessments conducted at 6 sites at Baker Island in the US...

  12. Intramuscular dissection of Baker's cysts: report on three cases

    International Nuclear Information System (INIS)

    Fang, Christopher S.J.; McCarthy, Catherine L.; McNally, Eugene G.

    2004-01-01

    Baker's cysts are fluid distensions of the gastrocnemius-semimembranosus bursa and are the most common cystic lesion around the knee. Typically cysts enlarge along intermuscular planes around the knee. We report three cases in which the expanding cyst did not respect these planes and dissected along an intramuscular route as confirmed by MR imaging. Such behaviour by Baker's cysts is hitherto unreported in the literature. Possible mechanisms to account for this phenomenon are discussed. (orig.)

  13. Biofortification of folates in white wheat bread by selection of yeast strain and process.

    Science.gov (United States)

    Hjortmo, Sofia; Patring, Johan; Jastrebova, Jelena; Andlid, Thomas

    2008-09-30

    We here demonstrate that folate content in yeast fermented food can be dramatically increased by using a proper (i) yeast strain and (ii) cultivation procedure for the selected strain prior to food fermentation. Folate levels were 3 to 5-fold higher in white wheat bread leavened with a Saccharomyces cerevisiae strain CBS7764, cultured in defined medium and harvested in the respiro-fermentative phase of growth prior to dough preparation (135-139 microg/100 dry matter), compared to white wheat bread leavened with commercial Baker's yeast (27-43 microg/100 g). The commercial Baker's yeast strain had been industrially produced, using a fed-batch process, thereafter compressed and stored in the refrigerator until bakings were initiated. This strategy is an attractive alternative to fortification of bread with synthetically produced folic acid. By using a high folate producing strain cultured a suitable way folate levels obtained were in accordance with folic acid content in fortified cereal products.

  14. Purification and Characterization of Enzymes from Yeast: An Extended Undergraduate Laboratory Sequence for Large Classes

    Science.gov (United States)

    Johanson, Kelly E.; Watt, Terry J.; McIntyre, Neil R.; Thompson, Marleesa

    2013-01-01

    Providing a project-based experience in an undergraduate biochemistry laboratory class can be complex with large class sizes and limited resources. We have designed a 6-week curriculum during which students purify and characterize the enzymes invertase and phosphatase from bakers yeast. Purification is performed in two stages via ethanol…

  15. Chemical signaling and insect attraction is a conserved trait in yeasts.

    Science.gov (United States)

    Becher, Paul G; Hagman, Arne; Verschut, Vasiliki; Chakraborty, Amrita; Rozpędowska, Elżbieta; Lebreton, Sébastien; Bengtsson, Marie; Flick, Gerhard; Witzgall, Peter; Piškur, Jure

    2018-03-01

    Yeast volatiles attract insects, which apparently is of mutual benefit, for both yeasts and insects. However, it is unknown whether biosynthesis of metabolites that attract insects is a basic and general trait, or if it is specific for yeasts that live in close association with insects. Our goal was to study chemical insect attractants produced by yeasts that span more than 250 million years of evolutionary history and vastly differ in their metabolism and lifestyle. We bioassayed attraction of the vinegar fly Drosophila melanogaster to odors of phylogenetically and ecologically distinct yeasts grown under controlled conditions. Baker's yeast Saccharomyces cerevisiae , the insect-associated species Candida californica , Pichia kluyveri and Metschnikowia andauensis , wine yeast Dekkera bruxellensis , milk yeast Kluyveromyces lactis , the vertebrate pathogens Candida albicans and Candida glabrata , and oleophilic Yarrowia lipolytica were screened for fly attraction in a wind tunnel. Yeast headspace was chemically analyzed, and co-occurrence of insect attractants in yeasts and flowering plants was investigated through a database search. In yeasts with known genomes, we investigated the occurrence of genes involved in the synthesis of key aroma compounds. Flies were attracted to all nine yeasts studied. The behavioral response to baker's yeast was independent of its growth stage. In addition to Drosophila , we tested the basal hexapod Folsomia candida (Collembola) in a Y-tube assay to the most ancient yeast, Y. lipolytica, which proved that early yeast signals also function on clades older than neopteran insects. Behavioral and chemical data and a search for selected genes of volatile metabolites underline that biosynthesis of chemical signals is found throughout the yeast clade and has been conserved during the evolution of yeast lifestyles. Literature and database reviews corroborate that yeast signals mediate mutualistic interactions between insects and yeasts

  16. Shuffling cards, factoring numbers and the quantum baker's map

    International Nuclear Information System (INIS)

    Lakshminarayan, Arul

    2005-01-01

    It is pointed out that an exactly solvable permutation operator, viewed as the quantization of cyclic shifts, is useful in constructing a basis in which to study the quantum baker's map, a paradigm system of quantum chaos. In the basis of this operator the eigenfunctions of the quantum baker's map are compressed by factors of around five or more. We show explicitly its connection to an operator that is closely related to the usual quantum baker's map. This permutation operator has interesting connections to the art of shuffling cards as well as to the quantum factoring algorithm of Shor via the quantum order finding one. Hence we point out that this well-known quantum algorithm makes crucial use of a quantum chaotic operator, or at least one that is close to the quantization of the left-shift, a closeness that we also explore quantitatively. (letter to the editor)

  17. Malignant pleural mesothelioma in bakers and pastry cooks.

    Science.gov (United States)

    Ascoli, V; Calisti, R; Carnovale-Scalzo, C; Nardi, F

    2001-10-01

    The occurrence of malignant pleural mesothelioma (MPM) among bakers and pastry cooks has never been documented. We detected eight cases of MPM in bakers, pastry cooks, and biscuit cooks engaged in making, baking/cooking, and selling pastry/bread in two hospital-based series (Rome and Orbassano/Turin, Italy; period 1990-1997; 222 cases). Field-investigations revealed asbestos-containing material (ACM) in ovens for baking bread, that were manufactured prior to the 1980s. It is suggested that there is a possible new association of the risk of having worked as a baker or pastry cook and MPM. Presumptive source of exposure to asbestos was the use of asbestos-insulated ovens. Copyright 2001 Wiley-Liss, Inc.

  18. Quantum baker maps with controlled-not coupling

    International Nuclear Information System (INIS)

    Vallejos, Raul O; Santoro, Pedro R del; Almeida, Alfredo M Ozorio de

    2006-01-01

    The characteristic stretching and squeezing of chaotic motion is linearized within the finite number of phase space domains which subdivide a classical baker map. Tensor products of such maps are also chaotic, but a more interesting generalized baker map arises if the stacking orders for the factor maps are allowed to interact. These maps are readily quantized, in such a way that the stacking interaction is entirely attributed to primary qubits in each map, if each jth subsystem has Hilbert space dimension D j 2 n j . We here study the particular example of two baker maps that interact via a controlled-not interaction, which is a universal gate for quantum computation. Numerical evidence indicates that the control subspace becomes an ideal Markovian environment for the target map in the limit of large Hilbert space dimension

  19. USA sender Able og Baker en tur i rummet

    DEFF Research Database (Denmark)

    Alstrup, Aage Kristian Olsen

    2014-01-01

    DETTE ER DEN TREDJE ARTIKEL I SERIEN OM DYRENES ROLLE I RUMFORSKNINGEN. VI SKAL MØDE DE TO PRIMATER ABLE OG BAKER, SOM NASA SUCCESFULDT SENDTE EN TUR I RUMMET I MAJ 1959 – HALVANDET ÅR EFTER, AT SOVJETUNIONEN HAVDE SENDT HUNDEN LAIKA DERUD.......DETTE ER DEN TREDJE ARTIKEL I SERIEN OM DYRENES ROLLE I RUMFORSKNINGEN. VI SKAL MØDE DE TO PRIMATER ABLE OG BAKER, SOM NASA SUCCESFULDT SENDTE EN TUR I RUMMET I MAJ 1959 – HALVANDET ÅR EFTER, AT SOVJETUNIONEN HAVDE SENDT HUNDEN LAIKA DERUD....

  20. 76 FR 72718 - Notice of Availability of the Draft Baker Resource Management Plan and Environmental Impact...

    Science.gov (United States)

    2011-11-25

    ... following methods: Web site: http://www.blm.gov/or/districts/vale/plans/bakerrmp/contact.php . Email: Baker... above address or may be viewed at: http://www.blm.gov/or/districts/vale/plans/bakerrmp/index.php . FOR... will revise the existing Baker RMP of 1989 and provide the Baker Field Office with an updated framework...

  1. Framework for Sustaining Innovation at Baker Library, Harvard Business School

    Science.gov (United States)

    Dolan, Meghan; Hemment, Michael; Oliver, Stephanie

    2017-01-01

    Baker Library at Harvard Business School is increasingly asked by the school's faculty to create custom digital information products to enhance course assignments and to find novel ways of electronically disseminating faculty research. In order to prioritize these requests, as well as facilitate, manage, and track the resulting projects, the…

  2. Senecio grisebachii Baker: Pyrrolizidine alkaloids and experimental poisoning in calves

    Science.gov (United States)

    The main objectives of this study were to determine the 1,2-dehydropyrrolizidine alkaloid (DHPA) content in Senecio grisebachii Baker (Compositae), to experimentally demonstrate its toxicity in calves and to describe the main clinical and pathological findings of this toxicity. S. grisebachii plants...

  3. A “pessoa” de Rudder Baker é realmente incorporada?

    Directory of Open Access Journals (Sweden)

    Jonas Gonçalves Coelho

    2008-06-01

    Full Text Available Some philosophers materialists think, against the dualism of substance, that an embodied mind is only a mind that depends on a body to exist, that is, that the mind doesn’t exist independently of a body. I will take as representative of this very limited point of view about embodiment the ideas of Lynne Baker and her Constitution View. Baker says that she prefers to face the problem of the relationship between persons and bodies than the problem of the relationship between mind and body because this last formulation of the problem implies the idea of a mind distinct and separated of the body while the first is more according of her view of an embodied and situated mind. But the problem is that Baker forgets it when she defines persons in terms of first-person perspective or self-consciousness. Although, Baker says that the self-consciousness depends on structural – a body – and environmental – the situation – conditions, what becomes a self-conscious human person an entity ontologically distinct of the body that constitutes it and of other animals are their realizations like arts, philosophy, science, moral, etc. It looks like that for Baker the self-consciousness is not only a necessary condition but also a sufficient one for that human realizations, while the body fulfill only an indirect role. Against these ideas we can ask: the great realizations that distinguish the human persons of other animals would be possible independently of the biological constitution of our body and its needs?

  4. 113Cd-NMR investigation of a cadmium-substituted copper, zinc-containing superoxide dismutase from yeast

    DEFF Research Database (Denmark)

    Kofod, Pauli; Bauer, Rogert; Danielsen, Eva

    1991-01-01

    113Cd nuclear magnetic resonance spectroscopy has been used to investigate the metal binding sites of cadmium-substituted copper,zinc-containing superoxide dismutase from baker's yeast. NMR signals were obtained for 113Cd(II) at the Cu site as well as for 113Cd(II) at the Zn site. The two subunits...

  5. Phosphorylation site on yeast pyruvate dehydrogenase complex

    International Nuclear Information System (INIS)

    Uhlinger, D.J.

    1986-01-01

    The pyruvate dehydrogenase complex was purified to homogeneity from baker's yeast (Saccharomyces cerevisiae). Yeast cells were disrupted in a Manton-Gaulin laboratory homogenizer. The pyruvate dehydrogenase complex was purified by fractionation with polyethylene glycol, isoelectric precipitation, ultracentrifugation and chromatography on hydroxylapatite. Final purification of the yeast pyruvate dehydrogenase complex was achieved by cation-exchange high pressure liquid chromatography (HPLC). No endogenous pyruvate dehydrogenase kinase activity was detected during the purification. However, the yeast pyruvate dehydrogenase complex was phosphorylated and inactivated with purified pyruvate dehydrogenase kinase from bovine kidney. Tryptic digestion of the 32 P-labeled complex yielded a single phosphopeptide which was purified to homogeniety. The tryptic digest was subjected to chromatography on a C-18 reverse phase HPLC column with a linear gradient of acetonitrile. Radioactive fractions were pooled, concentrated, and subjected to anion-exchange HPLC. The column was developed with a linear gradient of ammonium acetate. Final purification of the phosphopeptide was achieved by chromatography on a C-18 reverse phase HPLC column developed with a linear gradient of acetonitrile. The amino acid sequence of the homogeneous peptide was determined by manual modified Edman degradation

  6. The impact of yeast fermentation on dough matrix properties.

    Science.gov (United States)

    Rezaei, Mohammad N; Jayaram, Vinay B; Verstrepen, Kevin J; Courtin, Christophe M

    2016-08-01

    Most studies on dough properties are performed on yeastless dough to exclude the complicating, time-dependent effect of yeast. Baker's yeast, however, impacts dough matrix properties during fermentation, probably through the production of primary (CO2 and ethanol) and secondary (glycerol, acetic acid and succinic acid) metabolites. The aim of this study is to obtain a better understanding of the changes in yeasted dough behavior introduced by fermentation, by investigating the impact of yeast fermentation on Farinograph dough consistency, dough spread, Kieffer rig dough extensibility and gluten agglomeration behavior in a fermented dough-batter gluten starch separation system. Results show that fermentation leads to a dough with less flow and lower extensibility that breaks more easily under stress and strain. The dough showed less elastic and more plastic deformation behavior. Gluten agglomerates were smaller for yeasted dough than for the unyeasted control. These changes probably have to be attributed to metabolites generated during fermentation. Indeed, organic acids and also ethanol in concentrations produced by yeast were previously shown to have similar effects in yeastless dough. These findings imply the high importance of yeast fermentation metabolites on dough matrix properties in industrial bread production. © 2015 Society of Chemical Industry. © 2015 Society of Chemical Industry.

  7. National Uranium Resource Evaluation: Baker Quadrangle, Oregon and Idaho

    International Nuclear Information System (INIS)

    Bernardi, M.L.; Robins, J.W.

    1982-05-01

    The Baker Quadrangle, Oregon, and Idaho, was evaluated to identify areas containing geologic environments favorable for uranium deposits. The criteria used was developed for the National Uranium Resource Evaluation program. Stream-sediment reconnaissance and detailed surface studies were augmented by subsurface-data interpretion and an aerial radiometric survey. Results indicate that lower Pliocene sedimentary rocks in the Lower Powder River Valley-Virtue Flat basin are favorable characteristics, they remain unevaluated because of lack of subsurface data. Tertiary sandstones, possibly present at depth in the Long and Cascade Valleys, also remain unevaluated due to lack of subsurface data. All remaining environments in the Baker Quadrangle are unfavorable for all classes of uranium deposits

  8. Ross E. Baker, DC: A Canadian chiropractic survivor.

    Science.gov (United States)

    Brown, Douglas M

    2014-03-01

    This paper is an historical biography of a fortunate man. It begins with a glimpse of Ross E. Baker's origins in south-western Ontario, watches him going to school and working in Hamilton before joining the Canadian Army and shipping off to Europe to fight in the Second World War. At War's end, the article picks up Dr. Baker as he comes home, starts a family, becomes a chiropractor and sustains a viable practice. Now in the twilight of life, the good doctor is last seen content with his retirement, spending days at his cottage property, reviewing his memoirs and reflecting on the tumult, terror and eventual triumph of the D-Day landing at Normandy.

  9. Direct concentration and viability measurement of yeast in corn mash using a novel imaging cytometry method.

    Science.gov (United States)

    Chan, Leo L; Lyettefi, Emily J; Pirani, Alnoor; Smith, Tim; Qiu, Jean; Lin, Bo

    2011-08-01

    Worldwide awareness of fossil-fuel depletion and global warming has been increasing over the last 30 years. Numerous countries, including the USA and Brazil, have introduced large-scale industrial fermentation facilities for bioethanol, biobutanol, or biodiesel production. Most of these biofuel facilities perform fermentation using standard baker's yeasts that ferment sugar present in corn mash, sugar cane, or other glucose media. In research and development in the biofuel industry, selection of yeast strains (for higher ethanol tolerance) and fermentation conditions (yeast concentration, temperature, pH, nutrients, etc.) can be studied to optimize fermentation performance. Yeast viability measurement is needed to identify higher ethanol-tolerant yeast strains, which may prolong the fermentation cycle and increase biofuel output. In addition, yeast concentration may be optimized to improve fermentation performance. Therefore, it is important to develop a simple method for concentration and viability measurement of fermenting yeast. In this work, we demonstrate an imaging cytometry method for concentration and viability measurements of yeast in corn mash directly from operating fermenters. It employs an automated cell counter, a dilution buffer, and staining solution from Nexcelom Bioscience to perform enumeration. The proposed method enables specific fluorescence detection of viable and nonviable yeasts, which can generate precise results for concentration and viability of yeast in corn mash. This method can provide an essential tool for research and development in the biofuel industry and may be incorporated into manufacturing to monitor yeast concentration and viability efficiently during the fermentation process.

  10. Allergic airway disease in Italian bakers and pastry makers.

    Science.gov (United States)

    De Zotti, R; Larese, F; Bovenzi, M; Negro, C; Molinari, S

    1994-08-01

    A survey was carried out on respiratory symptoms and skin prick test response to common allergens (atopy), storage mites, and occupational allergens among 226 bakers and pastry makers from 105 small businesses in northern Italy. Atopy was present in 54 workers (23.4%); 40 workers (17.7%) were skin positive to at least one storage mite, 27 (11.9%) to wheat flour and 17 (7.5%) to alpha-amylase. Work related asthma was reported by 11 (4.9%) workers and rhinoconjunctivitis by 31 (17.7%); 22 workers (10.2%) complained of chronic bronchitis. The distribution of skin prick test results among bakers and among 119 white collar workers did not indicate (by logistic analysis) an increased risk for bakers to skin sensitisation to common allergens, storage mite, or to a group of five flours. Sensitisation to wheat flour, on the other hand, was present only among exposed workers. Skin sensitisation to occupational allergens was significantly associated with atopy (p < 0.001), smoking habit (p = 0.015), and work seniority (p = 0.027). The risk of work related symptoms was associated with sensitisation to wheat or alpha-amylase, and with atopy, but not with sensitisation to storage mites, work seniority, or smoking habit. The results of the study indicate that there is still a significant risk of allergic respiratory disease among Italian bakers. Not only wheat allergens, but also alpha-amylase must be considered as causative agents, although sensitisation to storage mites is not important in the occupational allergic response. Atopy must be regarded as an important predisposing factor for skin sensitisation to occupational allergens and for the onset of symptoms at work. The data confirm that for effective prevention, greater care should be taken not only in limiting environmental exposure, but also in identifying susceptible people.

  11. Maximal reductions in the Baker-Hausdorff formula

    International Nuclear Information System (INIS)

    Kolsrud, M.

    1992-05-01

    A preliminary expression for the Baker-Hausdorff formula is found up to ninth order, i.e. a series expansion of z in terms of multiple commutators, where e x =e x e y with x and y non-commuting, up to ninth degree in x,y. By means of complete sets of linear relations between multiple commutators, maximal reduction of the number of different multiple commutators in the series is obtained. 4 refs

  12. Zinc oxide and silver nanoparticles toxicity in the baker's yeast, Saccharomyces cerevisiae.

    Science.gov (United States)

    Galván Márquez, Imelda; Ghiyasvand, Mergan; Massarsky, Andrey; Babu, Mohan; Samanfar, Bahram; Omidi, Katayoun; Moon, Thomas W; Smith, Myron L; Golshani, Ashkan

    2018-01-01

    Engineered nanomaterials (ENMs) are increasingly incorporated into a variety of commercial applications and consumer products; however, ENMs may possess cytotoxic properties due to their small size. This study assessed the effects of two commonly used ENMs, zinc oxide nanoparticles (ZnONPs) and silver nanoparticles (AgNPs), in the model eukaryote Saccharomyces cerevisiae. A collection of ≈4600 S. cerevisiae deletion mutant strains was used to deduce the genes, whose absence makes S. cerevisiae more prone to the cytotoxic effects of ZnONPs or AgNPs. We demonstrate that S. cerevisiae strains that lack genes involved in transmembrane and membrane transport, cellular ion homeostasis, and cell wall organization or biogenesis exhibited the highest sensitivity to ZnONPs. In contrast, strains that lack genes involved in transcription and RNA processing, cellular respiration, and endocytosis and vesicular transport exhibited the highest sensitivity to AgNPs. Secondary assays confirmed that ZnONPs affected cell wall function and integrity, whereas AgNPs exposure decreased transcription, reduced endocytosis, and led to a dysfunctional electron transport system. This study supports the use of S. cerevisiae Gene Deletion Array as an effective high-throughput technique to determine cellular targets of ENM toxicity.

  13. Optimization of Baker's Yeast Production on Date Extract Using Response Surface Methodology (RSM).

    Science.gov (United States)

    Kara Ali, Mounira; Outili, Nawel; Ait Kaki, Asma; Cherfia, Radia; Benhassine, Sara; Benaissa, Akila; Kacem Chaouche, Noreddine

    2017-08-07

    This work aims to study the production of the biomass of S. cerevisiae on an optimized medium using date extract as the only carbon source in order to obtain a good yield of the biomass. The biomass production was carried out according to the central composite experimental design (CCD) as a response surface methodology using Minitab 16 software. Indeed, under optimal biomass production conditions, temperature (32.9 °C), pH (5.35) and the total reducing sugar extracted from dates (70.93 g/L), S. cerevisiae produced 40 g/L of their biomass in an Erlenmeyer after only 16 h of fermentation. The kinetic performance of the S. cerevisiae strain was investigated with three unstructured models i.e., Monod, Verhulst, and Tessier. The conformity of the experimental data fitted showed a good consistency with Monod and Tessier models with R² = 0.945 and 0.979, respectively. An excellent adequacy was noted in the case of the Verhulst model ( R² = 0.981). The values of kinetic parameters ( Ks , X m , μ m , p and q ) calculated by the Excel software, confirmed that Monod and Verhulst were suitable models, in contrast, the Tessier model was inappropriately fitted with the experimental data due to the illogical value of Ks (-9.434). The profiles prediction of the biomass production with the Verhulst model, and that of the substrate consumption using Leudeking Piret model over time, demonstrated a good agreement between the simulation models and the experimental data.

  14. Yeast redoxyendonuclease, a DNA repair enzyme similar to Escherichia coli endonuclease III

    International Nuclear Information System (INIS)

    Gossett, J.; Lee, K.; Cunningham, R.P.; Doetsch, P.W.

    1988-01-01

    A DNA repair endonuclease (redoxyendonuclease) was isolated from bakers' yeast (Saccharomyces cerevisiae). The enzyme has been purified by a series of column chromatography steps and cleaves OsO 4 -damaged, double-stranded DNA at sites of thymine glycol and heavily UV-irradiated DNA at sites of cytosine, thymine, and guanine photoproducts. The base specificity and mechanism of phosphodiester bond cleavage for the yeast redoxyendonuclease appear to be identical with those of Escherichia coli endonuclease III when thymine glycol containing, end-labeled DNA fragments of defined sequence are employed as substrates. Yeast redoxyendonuclease has an apparent molecular size of 38,000-42,000 daltons and is active in the absence of divalent metal cations. The identification of such an enzyme in yeast may be of value in the elucidation of the biochemical basis for radiation sensitivity in certain yeast mutants

  15. Hydrothermal decomposition of yeast cells for production of proteins and amino acids

    Energy Technology Data Exchange (ETDEWEB)

    Lamoolphak, Wiwat [Department of Chemical Engineering, Faculty of Engineering, Chulalongkorn University, Patumwan, Payathai Road, Bangkok 10330 (Thailand); Goto, Motonobu [Department of Applied Chemistry and Biochemistry, Kumamoto University, Kumamoto 850-8555 (Japan); Sasaki, Mitsuru [Department of Applied Chemistry and Biochemistry, Kumamoto University, Kumamoto 850-8555 (Japan); Suphantharika, Manop [Department of Biotechnology, Faculty of Science, Mahidol University, Rama VI Road, Bangkok 10400 (Thailand); Muangnapoh, Chirakarn [Department of Chemical Engineering, Faculty of Engineering, Chulalongkorn University, Patumwan, Payathai Road, Bangkok 10330 (Thailand); Prommuag, Chattip [Department of Chemical Engineering, Faculty of Engineering, Chulalongkorn University, Patumwan, Payathai Road, Bangkok 10330 (Thailand); Shotipruk, Artiwan [Department of Chemical Engineering, Faculty of Engineering, Chulalongkorn University, Patumwan, Payathai Road, Bangkok 10330 (Thailand)]. E-mail: artiwan.s@chula.ac.th

    2006-10-11

    This study examines hydrothermal decomposition of Baker's yeast cells, used as a model for spent Brewer's yeast waste, into protein and amino acids. The reaction was carried out in a closed batch reactor at various temperatures between 100 and 250 deg. C. The reaction products were separated into water-soluble and solid residue. The results demonstrated that the amount of yeast residue decreased with increasing hydrolysis temperature. After 20 min reaction in water at 250 deg. C, 78% of yeast was decomposed. The highest amount of protein produced was also obtained at this condition and was found to be 0.16 mg/mg dry yeast. The highest amount of amino acids (0.063 mg/mg dry yeast) was found at the lowest temperature tested after 15 min. The hydrolysis product obtained at 200 deg. C was tested as a nutrient source for yeast growth. The growth of yeast cells in the culture medium containing 2 w/v% of this product was comparable to that of the cells grown in the medium containing commercial yeast extract at the same concentration. These results demonstrated the feasibility of using subcritical water to potentially decompose proteinaceous waste such as spent Brewer's yeast while recovering more useful products.

  16. Hydrothermal decomposition of yeast cells for production of proteins and amino acids

    International Nuclear Information System (INIS)

    Lamoolphak, Wiwat; Goto, Motonobu; Sasaki, Mitsuru; Suphantharika, Manop; Muangnapoh, Chirakarn; Prommuag, Chattip; Shotipruk, Artiwan

    2006-01-01

    This study examines hydrothermal decomposition of Baker's yeast cells, used as a model for spent Brewer's yeast waste, into protein and amino acids. The reaction was carried out in a closed batch reactor at various temperatures between 100 and 250 deg. C. The reaction products were separated into water-soluble and solid residue. The results demonstrated that the amount of yeast residue decreased with increasing hydrolysis temperature. After 20 min reaction in water at 250 deg. C, 78% of yeast was decomposed. The highest amount of protein produced was also obtained at this condition and was found to be 0.16 mg/mg dry yeast. The highest amount of amino acids (0.063 mg/mg dry yeast) was found at the lowest temperature tested after 15 min. The hydrolysis product obtained at 200 deg. C was tested as a nutrient source for yeast growth. The growth of yeast cells in the culture medium containing 2 w/v% of this product was comparable to that of the cells grown in the medium containing commercial yeast extract at the same concentration. These results demonstrated the feasibility of using subcritical water to potentially decompose proteinaceous waste such as spent Brewer's yeast while recovering more useful products

  17. Yeast synthetic biology for the production of recombinant therapeutic proteins.

    Science.gov (United States)

    Kim, Hyunah; Yoo, Su Jin; Kang, Hyun Ah

    2015-02-01

    The production of recombinant therapeutic proteins is one of the fast-growing areas of molecular medicine and currently plays an important role in treatment of several diseases. Yeasts are unicellular eukaryotic microbial host cells that offer unique advantages in producing biopharmaceutical proteins. Yeasts are capable of robust growth on simple media, readily accommodate genetic modifications, and incorporate typical eukaryotic post-translational modifications. Saccharomyces cerevisiae is a traditional baker's yeast that has been used as a major host for the production of biopharmaceuticals; however, several nonconventional yeast species including Hansenula polymorpha, Pichia pastoris, and Yarrowia lipolytica have gained increasing attention as alternative hosts for the industrial production of recombinant proteins. In this review, we address the established and emerging genetic tools and host strains suitable for recombinant protein production in various yeast expression systems, particularly focusing on current efforts toward synthetic biology approaches in developing yeast cell factories for the production of therapeutic recombinant proteins. © FEMS 2015. All rights reserved. For permissions, please e-mail: journals.permission@oup.com.

  18. 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.

  19. [Mitochondria inheritance in yeast saccharomyces cerevisiae].

    Science.gov (United States)

    Fizikova, A Iu

    2011-01-01

    The review is devoted to the main mechanisms of mitochondria inheritance in yeast Saccharonmyces cerevisiae. The genetic mechanisms of functionally active mitochondria inheritance in eukaryotic cells is one of the most relevant in modem researches. A great number of genetic diseases are associated with mitochondria dysfunction. Plasticity of eukaryotic cell metabolism according to the environmental changes is ensured by adequate mitochondria functioning by means of ATP synthesis coordination, reactive oxygen species accumulation, apoptosis regulation and is an important factor of cell adaptation to stress. Mitochondria participation in important for cell vitality processes masters the presence of accurate mechanisms of mitochondria functions regulation according to environment fluctuations. The mechanisms of mitochondria division and distribution are highly conserved. Baker yeast S. cerevisiae is an ideal model object for mitochondria researches due to energetic metabolism lability, ability to switch over respiration to fermentation, and petite-positive phenotype. Correction of metabolism according to the environmental changes is necessary for cell vitality. The influence of respiratory, carbon, amino acid and phosphate metabolism on mitochondria functions was shown. As far as the mechanisms that stabilize functions of mitochondria and mtDNA are highly conserve, we can project yeast regularities on higher eukaryotes systems. This makes it possible to approximate understanding the etiology and pathogenesis of a great number of human diseases.

  20. Respiratory symptoms and sensitization in bread and cake bakers.

    Science.gov (United States)

    Smith, T A; Smith, P W

    1998-07-01

    This purpose of this study was to examine the relationship between exposure to wheat flour, soya flour and fungal amylase and the development of work-related symptoms and sensitization in bread and cake bakery employees who have regular exposure to these substances. The study populations consisted of 394 bread bakery workers and 77 cake bakery workers whose normal jobs involved the sieving, weighing and mixing of ingredients. The groups were interviewed with the aim of identifying the prevalence, nature and pattern of any work-related respiratory symptoms. They were also skin-prick tested against the common bakery sensitizing agents, i.e., wheat flour, soya flour, rice flour and fungal amylase. The results of personal sampling for sieving, weighing and mixing operations at the bakeries from which the study groups were taken were collated in order to determine typical exposures to total inhalable dust from the ingredients, expressed as 8 hour time-weighted average exposures. Data from the health surveillance and collated dust measurements were compared with the aim of establishing an exposure-response relationship for sensitization. The prevalence of work-related symptoms in bread bakery and cake bakery ingredient handlers was 20.4% and 10.4% respectively. However, in a large proportion of those reporting symptoms in connection with work, the symptoms were intermittent and of short duration. It is considered that the aetiology of such symptoms is likely to be due to a non-specific irritant effect of high total dust levels, rather than allergy. None of the cake bakers and only 3.1% of the bread bakers had symptoms which were thought to be due to allergy to baking ingredients. Using skin-prick testing as a marker of sensitization, the prevalence of positive tests to wheat flour was 6% for the bread bakers and 3% for the cake bakers. Comparable prevalences for soya flour were 7% and 1% respectively. However, the prevalence of positive skin-prick tests to fungal amylase

  1. Mount Baker lahars and debris flows, ancient, modern, and future

    Science.gov (United States)

    Tucker, David S; Scott, Kevin M.; Grossman, Eric E.; Linneman, Scott

    2014-01-01

    The Middle Fork Nooksack River drains the southwestern slopes of the active Mount Baker stratovolcano in northwest Washington State. The river enters Bellingham Bay at a growing delta 98 km to the west. Various types of debris flows have descended the river, generated by volcano collapse or eruption (lahars), glacial outburst floods, and moraine landslides. Initial deposition of sediment during debris flows occurs on the order of minutes to a few hours. Long-lasting, down-valley transport of sediment, all the way to the delta, occurs over a period of decades, and affects fish habitat, flood risk, gravel mining, and drinking water.

  2. Breaking an encryption scheme based on chaotic baker map

    International Nuclear Information System (INIS)

    Alvarez, Gonzalo; Li, Shujun

    2006-01-01

    In recent years, a growing number of cryptosystems based on chaos have been proposed, many of them fundamentally flawed by a lack of robustness and security. This Letter describes the security weaknesses of a recently proposed cryptographic algorithm with chaos at the physical level based on the baker map. It is shown that the security is trivially compromised for practical implementations of the cryptosystem with finite computing precision and for the use of the iteration number n as the secret key. Some possible countermeasures to enhance the security of the chaos-based cryptographic algorithm are also discussed

  3. Building Abelian Functions with Generalised Baker-Hirota Operators

    Directory of Open Access Journals (Sweden)

    Matthew England

    2012-06-01

    Full Text Available We present a new systematic method to construct Abelian functions on Jacobian varieties of plane, algebraic curves. The main tool used is a symmetric generalisation of the bilinear operator defined in the work of Baker and Hirota. We give explicit formulae for the multiple applications of the operators, use them to define infinite sequences of Abelian functions of a prescribed pole structure and deduce the key properties of these functions. We apply the theory on the two canonical curves of genus three, presenting new explicit examples of vector space bases of Abelian functions. These reveal previously unseen similarities between the theories of functions associated to curves of the same genus.

  4. The Archives of the History of American Psychology: An Interview with David B. Baker.

    Science.gov (United States)

    Prieto, Loreto R.

    2001-01-01

    Presents an interview with David B. Baker, Director of the Archives of the History of American Psychology. Covers topics such as: Baker's interest in the history of psychology, his work at the Archives of the History of American Psychology, and recommendations for teachers when addressing history in non-history courses. (CMK)

  5. Harvesting yeast (Saccharomyces cerevisiae) at different physiological phases significantly affects its functionality in bread dough fermentation.

    Science.gov (United States)

    Rezaei, Mohammad N; Dornez, Emmie; Jacobs, Pieter; Parsi, Anali; Verstrepen, Kevin J; Courtin, Christophe M

    2014-05-01

    Fermentation of sugars into CO2, ethanol and secondary metabolites by baker's yeast (Saccharomyces cerevisiae) during bread making leads to leavening of dough and changes in dough rheology. The aim of this study was to increase our understanding of the impact of yeast on dough related aspects by investigating the effect of harvesting yeast at seven different points of the growth profile on its fermentation performance, metabolite production, and the effect on critical dough fermentation parameters, such as gas retention potential. The yeast cells harvested during the diauxic shift and post-diauxic growth phase showed a higher fermentation rate and, consequently, higher maximum dough height than yeast cells harvested in the exponential or stationary growth phase. The results further demonstrate that the onset of CO2 loss from fermenting dough is correlated with the fermentation rate of yeast, but not with the amount of CO2 that accumulated up to the onset point. Analysis of the yeast metabolites produced in dough yielded a possible explanation for this observation, as they are produced in different levels depending on physiological phase and in concentrations that can influence dough matrix properties. Together, our results demonstrate a strong effect of yeast physiology at the time of harvest on subsequent dough fermentation performance, and hint at an important role of yeast metabolites on the subsequent gas holding capacity. Copyright © 2013 Elsevier Ltd. All rights reserved.

  6. Ultrasound guided percutaneous treatment and follow-up of Baker's cyst in knee osteoarthritis

    International Nuclear Information System (INIS)

    Köroğlu, Mert; Çallıoğlu, Mehmet; Eriş, Hüseyin Naim; Kayan, Mustafa; Çetin, Meltem; Yener, Mahmut; Gürses, Cemil; Erol, Bekir; Türkbey, Barış; Parlak, Ayşe Eda; Akhan, Okan

    2012-01-01

    Objective: Purpose of this study is to assess sonographic changes and clinical response in different subgroups of Baker's cyst patients with knee osteoarthritis after a single session of ultrasound-guided percutaneous aspiration and corticosteroid injection. Materials and methods: Thirty-two knee osteoarthritis patients (46–85 years, mean 58.97 ± 9.88) with symptomatic Baker's cyst diagnosed at ultrasonography were included in the study. To determine the grade of the symptoms, Visual Analogue Scale was applied. The patients were grouped in two, as simple (n = 24) and complex (n = 8) Baker's cyst. Thirty-two ultrasound-guided cyst aspirations concomitant 1 ml betamethasone injection (24 simple, 8 complex subgroups) were performed. Patients were followed clinically as well as via ultrasonography for 6 months after procedures. Results: A significant decrease in volume of the Baker's cysts after percutaneous treatment was accompanied by a significant clinical improvement. Moreover, the volume reduction of Baker's cyst after the treatment was significantly correlated with the clinical improvement (Pearson correlation coefficient = 0.542, p = 0.001). All 6 Baker's cysts relapsed at ultrasonography were complex type. Furthermore, a comparison of patients with simple Baker's cysts and those with complex Baker's cysts demonstrated no significant change in Visual Analogue Scale scores between two groups (p = 0.061, Mann–Whitney U). No complications (minor or major) occurred secondary to percutaneous treatment. Conclusion: Baker's cysts can be grouped as simple and complex groups via ultrasonography prior to the treatment. Cyst aspiration with ultrasound-guided corticosteroid injection yields clinical improvement and cyst volume reduction in all subgroups of patients with Baker's cyst secondary to knee osteoarthritis.

  7. Horizontal gene transfer promoted evolution of the ability to propagate under anaerobic conditions in yeasts

    DEFF Research Database (Denmark)

    Gojkovic, Zoran; Knecht, Wolfgang; Warneboldt, J.

    2004-01-01

    The ability to propagate under anaerobic conditions is an essential and unique trait of brewer's or baker's yeast (Saccharomyces cervisiae). To understand the evolution of facultative anaerobiosis we studied the dependence of de novo pyrimidine biosynthesis, more precisely the fourth enzymic...... activity catalysed by dihydroorotate dehydrogenase (DHODase), on the enzymes of the respiratory chain in several yeast species. While the majority of yeasts possess a mitochondrial DHODase, Saccharomyces cerevisiae has a cytoplasmatic enzyme, whose activity is independent of the presence of oxygen. From....... We show that these two S. kluyveri enzymes, and their coding genes, differ in their dependence on the presence of oxygen. Only the cytoplasmic DHODase promotes growth in the absence of oxygen. Apparently a Saccharomyces yeast progenitor which had a eukaryotic-like mitochondrial DHODase acquired...

  8. 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...

  9. Neoglacial fluctuations of Deming Glacier, Mt. Baker, Washington USA.

    Science.gov (United States)

    Osborn, G.; Menounos, B.; Scott, K.; Clague, J. J.; Tucker, D.; Riedel, J.; Davis, P.

    2007-12-01

    Deming Glacier flows from the upper west slopes of Mt. Baker, a stratovolcano in the Cascade Range of Washington, USA. The north and south lateral moraines of Deming Glacier are composed of at least four tills separated by layers of detrital wood and sheared stumps in growth position. The stratigraphy records fluctuations of the glacier during the Holocene. The outer ten rings of an in situ stump from the middle wood layer, which is about 40 m below the north lateral moraine crest and 1.2 km downvalley from the present glacier terminus, yielded an age of 1750 ± 50~~ 14C yr BP [1810-1550 cal yr BP]. The stump revealed at least 300 rings and thus records a period of landscape stability and relatively restricted glaciation for several hundred years prior to ca. 1750 14C yr BP . Samples from the lowest wood layer also have been submitted for radiocarbon dating. Outer rings of detrital wood samples collected from two wood mats exposed in the south lateral moraine, 2.3 km downvalley of the glacier terminus, returned radiocarbon ages of 1600 ± 30~~ 14C yr BP [1550- 1410 cal yr BP] and 430 ± 30~~ 14C yr BP [AD 1420-1620]. These data indicate that Deming Glacier advanced over a vegetated moraine sometime after 1810 cal yr BP to a position less extensive that it achieved at the peak of the Little Ice Age. The glacier then receded before it began its final and most extensive Holocene advance after AD 1420. The older advance is correlative with the 'First Millennium AD' advance, recently recognized throughout western North America. The younger advance coincides with an advance of Mt. Baker's Easton Glacier [AD 1430-1630], and advances of many alpine glaciers elsewhere in western North America. Our data suggest that glaciers on Mt. Baker fluctuated in a similar manner to alpine glaciers in the Coast Mountains of British Columbia and in other mountain ranges of northwest North America during Neoglaciation.

  10. The vertebrate fauna of Ichauway, Baker County, GA

    Science.gov (United States)

    Smith, L.L.; Steen, D.A.; Stober, J.M.; Freeman, Mary C.; Golladay, S.W.; Conner, L.M.; Cochrane, J.

    2006-01-01

    Less than 4% of the once extensive Pinus palustris (longleaf pine) ecosystem remains today. Although longleaf pine habitats are recognized for their high species diversity, few published accounts document the vertebrate faunas of remaining tracts. Here we report on the vertebrate species richness of lchauway, an 11,300-ha property in Baker County, GA. The property includes ca. 7300 ha of longleaf pine with native ground cover, along with more than 30 seasonal wetlands and ca. 45 km of riparian habitat associated with Ichawaynochaway Creek, Big Cypress Creek, and the Flint River. The fauna includes 61 species of fish, 31 amphibians, 53 reptiles, 191 birds, and 41 mammals. Despite the relative isolation of the property from other natural ecosystems, the vertebrate fauna of lchauway is remarkably diverse and may offer an example of reference conditions to guide restoration of longleaf pine forests, associated seasonal wetlands, and riparian areas elsewhere in the southeastern U S.

  11. The scholarly rebellion of the early Baker Street Irregulars

    Directory of Open Access Journals (Sweden)

    George Mills

    2017-03-01

    Full Text Available This work provides and analyzes an early institutional history of the pioneering Sherlock Holmes American fan club, the Baker Street Irregulars (BSI. Using the publications and records of these devoted Sherlockians, I track the BSI's development from a speakeasy gathering in 1934 to a national organization by the mid-1940s. This growth was built on a foundation of Victorian nostalgia and playful humor. Yet at the same time the members of the Irregulars took their fandom seriously, producing Sherlockian scholarship and creating an infrastructure of journals, conferences, and credentialing that directly mimicked the academy. They positioned themselves in contrast to prevailing scholarly practices of the period, such as New Criticism. I trace both how their fan practices developed over time and how this conflict with the academy led to many of the BSI's defining characteristics.

  12. Leaf Epidermis of the Rheophyte Dyckia brevifolia Baker (Bromeliaceae

    Directory of Open Access Journals (Sweden)

    Ghislaine Maria Lobo

    2013-01-01

    Full Text Available Some species of Dyckia Schult. f., including Dyckia brevifolia Baker, are rheophytes that live in the fast-moving water currents of streams and rivers which are subject to frequent flooding, but also period of low water. This study aimed to analyze the leaf epidermis of D. brevifolia in the context of epidermal adaptation to this aquatic plant’s rheophytic habitat. The epidermis is uniseriate, and the cuticle is thickened. The inner periclinal and anticlinal walls of the epidermal cells are thickened and lignified. Stomata are tetracytic, located in the depressions in relation to the surrounding epidermal cells, and covered by peltate trichomes. While the epidermal characteristics of D. brevifolia are similar to those of Bromeliaceae species, this species has made particular adaptations of leaf epidermis in response to its rheophytic environment.

  13. Interactions between Drosophila and its natural yeast symbionts-Is Saccharomyces cerevisiae a good model for studying the fly-yeast relationship?

    Science.gov (United States)

    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 used most often in D. melanogaster experiments is a commercially and industrially important strain that, to the best of our knowledge, was not isolated from flies. Since disrupting natural host-microbe interactions can have profound effects on host biology, the results from D. melanogaster-S. cerevisiae laboratory experiments may not be fully representative of host-microbe interactions in nature. In this study, we explore the D. melanogaster-yeast relationship using five different strains of yeast that were isolated from wild Drosophila populations. Ingested live yeasts have variable persistence in the D. melanogaster gastrointestinal tract. For example, Hanseniaspora occidentalis persists relative to S. cerevisiae, while Brettanomyces naardenensis is removed. Despite these differences in persistence relative to S. cerevisiae, we find that all yeasts decrease in total abundance over time. Reactive oxygen species (ROS) are an important component of the D. melanogaster anti-microbial response and can inhibit S. cerevisiae growth in the intestine. To determine if sensitivity to ROS explains the differences in yeast persistence, we measured yeast growth in the presence and absence of hydrogen peroxide. We find that B. naardenesis is completely inhibited by hydrogen peroxide, while H. occidentalis is not, which is consistent with yeast sensitivity to ROS affecting persistence within the D. melanogaster gastrointestinal tract. We also compared the feeding preference of D

  14. Mechanisms of uv mutagenesis in yeast and E. coli

    International Nuclear Information System (INIS)

    Lawrence, C.; Christensen, R.; Christensen, J.R.; O'Brien, T.

    1983-01-01

    Experiments investigating ultraviolet light mutagenesis in either bakers' yeast, Saccharomyces cerevisiae, or E. coli have led to the following conclusions. First, cyclobutane pyrimidine dimers cause most mutations in both organisms; pyrimidine adducts, such as PyC, can account at best for only a small proportion. 86 percent of forward mutations induced at the E. coli lacI locus can be abolished by photoreactivation under conditions which do not alter the level of recA induction. About 75 percent of the forward mutations induced at the CAN1 locus of yeast could be removed by photoreactivation, a value that lies within the range observed previously for the reversion of CYC1 alleles (60 percent - 97 percent). Second, about 10 percent of the lacI forward mutations are untargeted, a smaller fraction than found previously for cycl-91 reversion in yeast. It is not yet clear whether the two species are really different in this respect, of whether the cycl-91 reversion site is a typical of the yeast genome at large. Third, analysis of reversion frequencies of 20 mutant alleles suggests that about 10 to 25 percent of all replication errors produced by mutagenic mechanisms in uv-irradiated yeast involve additions or deletions of base-pairs, indicating that error-prone repair does not just produce substitutions. Last, the REV1 locus in yeast is concerned with the induction of frameshift mutations at some, but not all, genetic sites, just as found previously for substitution mutations. The function of the REV3 gene is more widely, though not universally, required while the function of the RAD6 gene, like that of the recA locus in E. coli, appears to be necessary for all kinds of uv mutagenesis. E coli genes comparable to REV1 and REV3 have not yet been described; conversely, there does not yet appear to be a yeast equivalent of umuC

  15. Mechanisms of uv mutagenesis in yeast and E. coli

    International Nuclear Information System (INIS)

    Lawrence, C.; Christensen, R.; Christensen, J.R.; O'Brien, T.

    1983-01-01

    Experiments investigating ultraviolet light mutagenesis in either bakers' yeast, Saccharomyces cerevisiae, or E. coli have led to the following conclusions. First, cyclobutane pyrimidine dimers cause most mutations in both organisms; pyrimidine adducts, such as PyC, can account at best for only a small proportion. Eighty-six percent of forward mutations induced at the E. coli lacI locus can be abolished by photoreactivation under conditions which do not alter the level of recA induction. About 75 percent of the forward mutations induced at the CAN1 locus of yeast could be removed by photoreactivation, a value that lies within the range observed previously for the reversion of CYC1 alleles (60 percent - 97 percent). Second, about 10 percent of the lacI forward mutations are untargeted, a smaller fraction than found previously for cycl1-91 reversion in yeast. It is not yet clear whether the two species are really different in this respect, or whether the cyc1-91 reversion site is atypical of the yeast genome at large. Third, analysis of reversion frequencies of 20 mutant alleles suggests that about 10 - 25 percent of all replication errors produced by mutagenic mechanisms in UV-irradiated yeast involve additions or deletions of base-pairs, indicating that error-prone repair does not just produce substitutions. Last, the REV1 locus in yeast is concerned with the induction of frameshift mutations at some, but not all, genetic sites, just as found previously for substitution mutations. The function of the REV3 gene is more widely, though not universally, required while the function of the RAD6 gene, like that of the recA locus in E. coli, appears to be necessary for all kinds of UV mutagenesis. E. coli genes comparable to REV1 and REV3 have not yet been described, conversely, there does not yet appear to be a yeast equivalent of umuC. 13 references, 4 tables

  16. Vaginal yeast infection

    Science.gov (United States)

    Yeast infection - vagina; Vaginal candidiasis; Monilial vaginitis ... Most women have a vaginal yeast infection at some time. Candida albicans is a common type of fungus. It is often found in small amounts ...

  17. Marketing research among small and medium-sized business enterprises - a VDEW field investigation with baker`s shops; Marktforschung bei Gewerbebetrieben - VDEW-Baeckereibefragung

    Energy Technology Data Exchange (ETDEWEB)

    Fischer, A. [Isar-Amperwerke AG, Muenchen (Germany); Nickel, M. [VDEW-Hauptgeschaeftsstelle, Frankfurt am Main (Germany). Gruppe ``Energiewirtschaft und Statistik``

    1998-12-14

    The baker`s trade is a business of interest to electric utilities, as bakers have a high demand for process heat and their supply requirements are characterized by simple load histories. Hence competing electric utilities in the competitive market target this customer group with increasing efforts. The authors summarize the information obtained from the field investigation and the conclusions drawn. (orig./CB) [Deutsch] Die Baeckereien sind wegen ihres hohen Prozesswaermebedarfs und des guenstigen Lastverlaufs eine interessante Kundengruppe fuer die Stromversorger. Der Beratung und Betreuung dieser Kunden muss deshalb hohe Aufmerksamkeit gewidmet werden. Nicht zuletzt wegen des Wettbewerbs auf dem Energiemarkt muessen die Stromversorger die Kundenorientierung noch intensivieren. Auch dadurch entstehen neue Anforderungen an die Kundenberatung und -betreuung. Die Verfasser erlaeutern die wichtigsten Ergebnisse und Schlussfolgerungen aus einer Befragung von Baeckereibetrieben. (orig.)

  18. Gridded multibeam bathymetry of Baker Island, Pacific Remote Island Areas, Central Pacific

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Gridded bathymetry at 40m resolution surrounding Baker Island, within the Pacific Remote Island Areas - Central Pacific Ocean. Bottom coverage was achieved in depths...

  19. A Survey of Hygiene Practices of Bakers in Amuwo Odofin Local ...

    African Journals Online (AJOL)

    A Survey of Hygiene Practices of Bakers in Amuwo Odofin Local Government ... pest control, hygiene of personnel, storage and waste management. Important as this strategy is in the food industry, little has been reported on the practice of ...

  20. CRED REA Algal Assessments at Baker Island, Pacific Remote Island Areas in 2008

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Twelve quadrats were sampled along 2 consecutively-placed, 25m transect lines, as part of Rapid Ecological Assessments, conducted at 1 site at Baker in the Pacific...

  1. CRED REA Fish Team Belt Transect Survey at Baker, Pacific Remote Island Areas, 2006

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Belt transects along 3 consecutively-placed, 25m transect lines were surveyed as part of Rapid Ecological Assessments conducted at 9 sites at Baker in the Pacific...

  2. Aerial Photography and Imagery, Ortho-Corrected - 2011 Digital Orthophotos - Baker County

    Data.gov (United States)

    NSGIC Education | GIS Inventory — This dataset is a collection of GeoTIFF natural color orthophotos covering Baker, Bradford, and Union counties within Florida. An orthophoto is remotely sensed image...

  3. Drug synergy drives conserved pathways to increase fission yeast lifespan.

    Directory of Open Access Journals (Sweden)

    Xinhe Huang

    Full Text Available Aging occurs over time with gradual and progressive loss of physiological function. Strategies to reduce the rate of functional loss and mitigate the subsequent onset of deadly age-related diseases are being sought. We demonstrated previously that a combination of rapamycin and myriocin reduces age-related functional loss in the Baker's yeast Saccharomyces cerevisiae and produces a synergistic increase in lifespan. Here we show that the same drug combination also produces a synergistic increase in the lifespan of the fission yeast Schizosaccharomyces pombe and does so by controlling signal transduction pathways conserved across a wide evolutionary time span ranging from yeasts to mammals. Pathways include the target of rapamycin complex 1 (TORC1 protein kinase, the protein kinase A (PKA and a stress response pathway, which in fission yeasts contains the Sty1 protein kinase, an ortholog of the mammalian p38 MAP kinase, a type of Stress Activated Protein Kinase (SAPK. These results along with previous studies in S. cerevisiae support the premise that the combination of rapamycin and myriocin enhances lifespan by regulating signaling pathways that couple nutrient and environmental conditions to cellular processes that fine-tune growth and stress protection in ways that foster long term survival. The molecular mechanisms for fine-tuning are probably species-specific, but since they are driven by conserved nutrient and stress sensing pathways, the drug combination may enhance survival in other organisms.

  4. Genetic manipulation of amylotic yeast for degradation of starch

    International Nuclear Information System (INIS)

    Nasim, A.

    1991-01-01

    The availability of a variety of techniques in Genetic Engineering has greatly facilitated the manipulation of hereditary material. These methodologies provide effective tools to utilize the existing microorganisms for creating novel combinations of hybrid strains for the degradation of substrates that can be converted into alcohol. Yeasts have several distinct advantages including the long standing industrial experience of scaling up the growth. The present report deals with the account of some experimental approaches used to obtained amylolytic yeast strains with ability to degrade starch. From among the naturally occurring yeasts schwanniomyces was found to be very efficient for this purpose. Both gene cloning and protoplast fusion were used to transfer DNA from Saccharomyces diastaticus to the bakers yeast Saccharomyces cerevisiae. The glucoamylase gene of S. diastaticus has been successfully cloned into S. cerevisiae. The observations are discussed as there relate to the current efforts to degrade substrates for energy placing special emphasis on the tremendous potential that naturally occurring microbes may have. This emphasizes the need to examine this aspect critically before initiating attempts to genetically engineer microbes for heterologous gene transfer, which appears to have serious limitations as far as the production of the end products adequate for industrial purposes are concerned. (author)

  5. The yeast genome may harbor hypoxia response elements (HRE).

    Science.gov (United States)

    Ferreira, Túlio César; Hertzberg, Libi; Gassmann, Max; Campos, Elida Geralda

    2007-01-01

    The hypoxia-inducible factor-1 (HIF-1) is a heterodimeric transcription factor activated when cells are submitted to hypoxia. The heterodimer is composed of two subunits, HIF-1alpha and the constitutively expressed HIF-1beta. During normoxia, HIF-1alpha is degraded by the 26S proteasome, but hypoxia causes HIF-1alpha to be stabilized, enter the nucleus and bind to HIF-1beta, thus forming the active complex. The complex then binds to the regulatory sequences of various genes involved in physiological and pathological processes. The specific regulatory sequence recognized by HIF-1 is the hypoxia response element (HRE) that has the consensus sequence 5'BRCGTGVBBB3'. Although the basic transcriptional regulation machinery is conserved between yeast and mammals, Saccharomyces cerevisiae does not express HIF-1 subunits. However, we hypothesized that baker's yeast has a protein analogous to HIF-1 which participates in the response to changes in oxygen levels by binding to HRE sequences. In this study we screened the yeast genome for HREs using probabilistic motif search tools. We described 24 yeast genes containing motifs with high probability of being HREs (p-value<0.1) and classified them according to biological function. Our results show that S. cerevisiae may harbor HREs and indicate that a transcription factor analogous to HIF-1 may exist in this organism.

  6. 'Yeast mail': a novel Saccharomyces application (NSA) to encrypt messages.

    Science.gov (United States)

    Rosemeyer, Helmut; Paululat, Achim; Heinisch, Jürgen J

    2014-09-01

    The universal genetic code is used by all life forms to encode biological information. It can also be used to encrypt semantic messages and convey them within organisms without anyone but the sender and recipient knowing, i.e., as a means of steganography. Several theoretical, but comparatively few experimental, approaches have been dedicated to this subject, so far. Here, we describe an experimental system to stably integrate encrypted messages within the yeast genome using a polymerase chain reaction (PCR)-based, one-step homologous recombination system. Thus, DNA sequences encoding alphabetical and/or numerical information will be inherited by yeast propagation and can be sent in the form of dried yeast. Moreover, due to the availability of triple shuttle vectors, Saccharomyces cerevisiae can also be used as an intermediate construction device for transfer of information to either Drosophila or mammalian cells as steganographic containers. Besides its classical use in alcoholic fermentation and its modern use for heterologous gene expression, we here show that baker's yeast can thus be employed in a novel Saccharomyces application (NSA) as a simple steganographic container to hide and convey messages. Copyright © 2014 Verlag Helvetica Chimica Acta AG, Zürich.

  7. Studying Functions of All Yeast Genes Simultaneously

    Science.gov (United States)

    Stolc, Viktor; Eason, Robert G.; Poumand, Nader; Herman, Zelek S.; Davis, Ronald W.; Anthony Kevin; Jejelowo, Olufisayo

    2006-01-01

    A method of studying the functions of all the genes of a given species of microorganism simultaneously has been developed in experiments on Saccharomyces cerevisiae (commonly known as baker's or brewer's yeast). It is already known that many yeast genes perform functions similar to those of corresponding human genes; therefore, by facilitating understanding of yeast genes, the method may ultimately also contribute to the knowledge needed to treat some diseases in humans. Because of the complexity of the method and the highly specialized nature of the underlying knowledge, it is possible to give only a brief and sketchy summary here. The method involves the use of unique synthetic deoxyribonucleic acid (DNA) sequences that are denoted as DNA bar codes because of their utility as molecular labels. The method also involves the disruption of gene functions through deletion of genes. Saccharomyces cerevisiae is a particularly powerful experimental system in that multiple deletion strains easily can be pooled for parallel growth assays. Individual deletion strains recently have been created for 5,918 open reading frames, representing nearly all of the estimated 6,000 genetic loci of Saccharomyces cerevisiae. Tagging of each deletion strain with one or two unique 20-nucleotide sequences enables identification of genes affected by specific growth conditions, without prior knowledge of gene functions. Hybridization of bar-code DNA to oligonucleotide arrays can be used to measure the growth rate of each strain over several cell-division generations. The growth rate thus measured serves as an index of the fitness of the strain.

  8. The influence of sucrose and maltose on Saccharomyces cerevisiae yeast multiplication

    Directory of Open Access Journals (Sweden)

    O. I. Ponomareva

    2016-01-01

    Full Text Available The data on the influence of fermentable carbohydrates concentration on yeast multiplication are widely represented in the literature. This study presents the results of experiments showing an influence of sucrose and maltose concentration on Saccharomyces cerevisiae yeast multiplication. The objects of this research are bakery, beer, wine and alcohol yeast that are widely used in fermentation industry. Beet molasses and malt wort were chosen as nutrient medium for yeast breeding. Their basic sugars are mainly represented by sucrose and maltose. The concentration of sugars was 9, 12, 16 and 20%. The intensity of yeast multiplication was evaluated based on yeast cells concentration during their cultivation and the specific growth rate. Sugar concentrations causing an intensive accumulation of examined yeast strains were determined. This paper presents the experimental data that were received describing the influence of sucrose and maltose concentration on the duration of a lag phase period for different yeast strains. Specific growth rates of researched strains were determined for nutrient mediums with different glucose and maltose concentrations. It was found that the Crabtree effect, that is caused by high carbohydrates concentration in culture medium, is most pronounced when yeast cells grow on a sucrose medium. Brewer’s and baker's yeast are more adapted to high concentrations of carbohydrates. The obtained experimental data could be utilized to develop flow charts of growing a pure culture of Saccharomyces cerevisiae yeast to use at fermentation plants, including low power ones.

  9. 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

  10. Coupled skinny baker's maps and the Kaplan-Yorke conjecture

    Science.gov (United States)

    Gröger, Maik; Hunt, Brian R.

    2013-09-01

    The Kaplan-Yorke conjecture states that for ‘typical’ dynamical systems with a physical measure, the information dimension and the Lyapunov dimension coincide. We explore this conjecture in a neighborhood of a system for which the two dimensions do not coincide because the system consists of two uncoupled subsystems. We are interested in whether coupling ‘typically’ restores the equality of the dimensions. The particular subsystems we consider are skinny baker's maps, and we consider uni-directional coupling. For coupling in one of the possible directions, we prove that the dimensions coincide for a prevalent set of coupling functions, but for coupling in the other direction we show that the dimensions remain unequal for all coupling functions. We conjecture that the dimensions prevalently coincide for bi-directional coupling. On the other hand, we conjecture that the phenomenon we observe for a particular class of systems with uni-directional coupling, where the information and Lyapunov dimensions differ robustly, occurs more generally for many classes of uni-directionally coupled systems (also called skew-product systems) in higher dimensions.

  11. Coupled skinny baker's maps and the Kaplan–Yorke conjecture

    International Nuclear Information System (INIS)

    Gröger, Maik; Hunt, Brian R

    2013-01-01

    The Kaplan–Yorke conjecture states that for ‘typical’ dynamical systems with a physical measure, the information dimension and the Lyapunov dimension coincide. We explore this conjecture in a neighborhood of a system for which the two dimensions do not coincide because the system consists of two uncoupled subsystems. We are interested in whether coupling ‘typically’ restores the equality of the dimensions. The particular subsystems we consider are skinny baker's maps, and we consider uni-directional coupling. For coupling in one of the possible directions, we prove that the dimensions coincide for a prevalent set of coupling functions, but for coupling in the other direction we show that the dimensions remain unequal for all coupling functions. We conjecture that the dimensions prevalently coincide for bi-directional coupling. On the other hand, we conjecture that the phenomenon we observe for a particular class of systems with uni-directional coupling, where the information and Lyapunov dimensions differ robustly, occurs more generally for many classes of uni-directionally coupled systems (also called skew-product systems) in higher dimensions. (paper)

  12. Obituary: Norman Hodgson Baker, Jr., 1931-2005

    Science.gov (United States)

    Helfand, David J.

    2005-12-01

    Norman H. Baker, a key contributor to the foundation of modern stellar pulsation theory and former editor of the "Astronomical Journal", died on 11 October 2005 in Watertown, New York near his beloved summer home in Natural Bridge. He succumbed to complications of Waldenstrom's macroglobulinemia, a bone marrow lymphoma that he had successfully surmounted for twenty-two years. Norm, as he was known to all, was born 23 October 1931 in Fergus Falls, Minnesota to Norman Hodgson and Jeannette (née Lieber) Baker. He attended the University of Minnesota where he met the first of many lifelong astronomical friends, Bill Erickson. He received his BA in 1952. He went on to do his PhD, "Radiation from Particle Interactions which Create Current," at Cornell University under Phil Morrison. He then moved to a postdoctoral position at the Max Planck Institut für Physik und Astrophysik in München with the intent of pursuing his work in plasma physics with Ludwig Biermann and Arnulf Schlüter. However, Rudolf (Rudi) Kippenhan snatched him away to pursue what became his lifelong interest, stellar physics. This was the dawn of the era in which electronic computers were becoming practical for scientific calculations, and Norm immediately adopted this new tool. Indeed, he remained at the forefront of computing technology throughout his life: He was certainly the first member of the Astronomy Department at Columbia to buy a Mac, and was undoubtedly one of the few emeritus professors in the world known by all the administrative staff as the first person to turn to when stumped by a computer problem. Following his first paper with Kippenhan on stellar rotation, Norm turned his attention to stellar pulsations, a topic he would pursue throughout his career. His 1962 paper in "Zeitschrift für Astrophysik" on pulsational models of Cepheids (Baker and Kippenhan 1962, 54, 155) is a classic in the field. The first figure displays the three dimensional model of the atmospheric absorption

  13. Kenneth Frank Baker--pioneer leader in plant pathology.

    Science.gov (United States)

    Cook, R James

    2005-01-01

    Kenneth F. Baker (1908-1996) made major contributions to understanding diseases of ornamental plants, seed pathology, soil-borne plant pathogens, biological control, and history of plant pathology. His work set the stage for the success of today's ornamentals and nursery industries. His leadership and writings created the scientific framework for research and teaching on soil-borne plant pathogens and biological control. After B.Sc. and Ph.D. degrees from Washington State University in 1930 and 1934, respectively, and one year as a National Research Council Fellow with B.M. Dugger at Wisconsin, he took jobs in 1935 with the U.S. Department of Agriculture in Nebraska on establishment of shelter belts and 1936-39 with the Pineapple Producers Cooperative Association in Hawaii. He worked on diseases of ornamental plants at the University of California, Los Angeles, starting in 1939, moving to Berkeley in 1961 when the UCLA program closed. He retired in 1975 and moved to Corvallis, OR, as Emeritus Professor, Oregon State University, and Collaborator, U.S. Department of Agriculture, Agricultural Research Service. He spent four sabbatical leaves in Australia, and was elected fellow of the American Association for the Advancement of Science in 1950, fellow of the American Phytopathological Society in 1969, and the Horticultural Hall of Fame in 1976.

  14. Vernonia condensata Baker (Asteraceae): A Promising Source of Antioxidants

    Science.gov (United States)

    da Silva, Jucélia Barbosa; Temponi, Vanessa dos Santos; Gasparetto, Carolina Miranda; Fabri, Rodrigo Luiz; Aragão, Danielle Maria de Oliveira; Pinto, Nícolas de Castro Campos; Ribeiro, Antônia; Scio, Elita; Del-Vechio-Vieira, Glauciemar; de Sousa, Orlando Vieira

    2013-01-01

    The present study evaluated the antioxidant potential of Vernonia condensata Baker (Asteraceae). Dried and powdered leaves were exhaustively extracted with ethanol by static maceration followed by partition to obtain the hexane, dichloromethane, ethyl acetate, and butanol fractions. Total phenols and flavonoids contents were determined through spectrophotometry and flavonoids were identified by HPLC-DAD system. The antioxidant activity was assessed by DPPH radical scavenging activity, TLC-bioautography, reducing power of Fe+3, phosphomolybdenum, and TBA assays. The total phenolic content and total flavonoids ranged from 0.19 to 23.11 g/100 g and from 0.13 to 4.10 g/100 g, respectively. The flavonoids apigenin and luteolin were identified in the ethyl acetate fraction. The IC50 of DPPH assay varied from 4.28 to 75.10 µg/mL and TLC-bioautography detected the antioxidant compounds. The reducing power of Fe+3 was 19.98 to 336.48 μg/mL, while the reaction with phosphomolybdenum ranged from 13.54% to 32.63% and 56.02% to 135.00% considering ascorbic acid and rutin as reference, respectively. At 30 mg/mL, the ethanolic extract and fractions revealed significant effect against lipid peroxidation. All these data sustain that V. condensata is an important and promising source of bioactive substances with antioxidant activity. PMID:24489987

  15. Performance evaluation of startup for a yeast membrane bioreactor (MBRy) treating landfill leachate.

    Science.gov (United States)

    Amaral, Míriam C S; Gomes, Rosimeire F; Brasil, Yara L; Oliveira, Sílvia M A; Moravia, Wagner G

    2017-12-06

    The startup process of a membrane bioreactor inoculated with yeast biomass (Saccharomyces cerevisiae) and used in the treatment of landfill leachate was evaluated. The yeast membrane bioreactor (MBRy) was inoculated with an exogenous inoculum, a granulated active dry commercial bakers' yeast. The MBRy was successfully started up with a progressive increase in the landfill leachate percentage in the MBRy feed and the use of Sabouraud Dextrose Broth. The membrane plays an important role in the startup phase because of its full biomass retention and removal of organic matter. MBRy is a suitable and promising process to treat recalcitrant landfill leachate. After the acclimation period, the COD and NH 3 removal efficiency reached values of 72 ± 3% and 39 ± 2% respectively. MBRy shows a low membrane-fouling potential. The membrane fouling was influenced by soluble microbial products, extracellular polymeric substances, sludge particle size, and colloidal dissolved organic carbon.

  16. Non-Genetic Engineering Approaches for Isolating and Generating Novel Yeasts for Industrial Applications

    Science.gov (United States)

    Chambers, P. J.; Bellon, J. R.; Schmidt, S. A.; Varela, C.; Pretorius, I. S.

    Generating novel yeast strains for industrial applications should be quite straightforward; after all, research into the genetics, biochemistry and physiology of Baker's Yeast, Saccharomyces cerevisiae, has paved the way for many advances in the modern biological sciences. We probably know more about this humble eukaryote than any other, and it is the most tractable of organisms for manipulation using modern genetic engineering approaches. In many countries, however, there are restrictions on the use of genetically-modified organisms (GMOs), particularly in foods and beverages, and the level of consumer acceptance of GMOs is, at best, variable. Thus, many researchers working with industrial yeasts use genetic engineering techniques primarily as research tools, and strain development continues to rely on non-GM technologies. This chapter explores the non-GM tools and strategies available to such researchers.

  17. Effect of the gamma radiation on the chemical, rheological, baker and microbiological properties in wheat flour

    International Nuclear Information System (INIS)

    Agundez A, Z.; Fernandez R, M.V.; Arce C, M.E.; Cruz Z, E.; Chernov, V.; Barboza F, M.

    2002-01-01

    The gamma radiation has been used in several places of the World as a sterilization method, preservation and pasteurization of foodstuffs, effect which is achieved due to diminishing or elimination of the microorganisms, reaching every time more acceptance, moreover eliminates the uses of toxic and carcinogenic substances, of general use, but at the present, being in the process of being totally prohibited, due to the higher risk in the human health. In this work the related results with the effects of the gamma radiation are presented, coming from a 60 Co source, in commercial wheat flour exposed to a dose of 1.0 KGy. The used dose is that allowed according to the NOM-033-SSA1-1993 standard. It was determined that the chemical characteristics of humidity, protein and ashes were not affected by radiation. The rheological properties neither suffer severe effects as consequence of radiation; the pharynographic and alveographic parameters were lightly affected by the treatment. Significant changes were detected in the percentage of water absorption and in the tolerance index to mixing. However a diminish of 10% in the development time and an increase of 13% in the stability was observed, for the irradiated samples respect to the those samples not irradiated. In relation to the alveograph parameters it was only detected a diminish of 7% in the force parameter (w) without changes in the tenacity/blowing up index ratio (P/L). The fall number diminish 11% indicating a small diminution in viscosity. The bakering properties do not turn out modified by the irradiation treatment finding a specific weight of 4.6 and 4.5 (cm 3 /g) for the control and irradiated samples, respectively. In the mesophyll analysis it was found a diminish of 96% from the original charge in control samples, observing a diminution of 74 and 25% in yeasts and mushrooms respectively. Microbiologically it was determined absence of total coliforms bacteria and faecal coliforms in the control samples and of

  18. An algorithm for the Baker-Campbell-Hausdorff formula

    Energy Technology Data Exchange (ETDEWEB)

    Matone, Marco [Dipartimento di Fisica e Astronomia “G. Galilei”, Istituto Nazionale di Fisica Nucleare, Università di Padova, Via Marzolo, 8-35131 Padova (Italy)

    2015-05-21

    A simple algorithm, which exploits the associativity of the BCH formula, and that can be generalized by iteration, extends the remarkable simplification of the Baker-Campbell-Hausdorff (BCH) formula, recently derived by Van-Brunt and Visser. We show that if [X,Y]=uX+vY+cI, [Y,Z]=wY+zZ+dI, and, consistently with the Jacobi identity, [X,Z]=mX+nY+pZ+eI, then exp (X)exp (Y)exp (Z)=exp (aX+bY+cZ+dI) where a, b, c and d are solutions of four equations. In particular, the Van-Brunt and Visser formula exp (X)exp (Z)=exp (aX+bZ+c[X,Z]+dI) extends to cases when [X,Z] contains also elements different from X and Z. Such a closed form of the BCH formula may have interesting applications both in mathematics and physics. As an application, we provide the closed form of the BCH formula in the case of the exponentiation of the Virasoro algebra, with SL{sub 2}(ℂ) following as a subcase. We also determine three-dimensional subalgebras of the Virasoro algebra satisfying the Van-Brunt and Visser condition. It turns out that the exponential form of SL{sub 2}(ℂ) has a nice representation in terms of its eigenvalues and of the fixed points of the corresponding Möbius transformation. This may have applications in Uniformization theory and Conformal Field Theories.

  19. 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...... with the focus on the different utilization of renewable feedstocks into fuels and chemicals has been intensively investigated due to increasing concerns on sustainability issues worldwide. Compared with its counterparts, Saccharomyces cerevisiae, the baker's yeast, is more industrially relevant due to known...... genetic and physiological background, the availability of a large collection of genetic tools, the compatibility of high-density and large-scale fermentation, and optimize the pathway for variety of products. Therefore, S. cerevisiae is one of the most popular cell factories and has been successfully used...

  20. A Double Perturbation Method for Reducing Dynamical Degradation of the Digital Baker Map

    Science.gov (United States)

    Liu, Lingfeng; Lin, Jun; Miao, Suoxia; Liu, Bocheng

    2017-06-01

    The digital Baker map is widely used in different kinds of cryptosystems, especially for image encryption. However, any chaotic map which is realized on the finite precision device (e.g. computer) will suffer from dynamical degradation, which refers to short cycle lengths, low complexity and strong correlations. In this paper, a novel double perturbation method is proposed for reducing the dynamical degradation of the digital Baker map. Both state variables and system parameters are perturbed by the digital logistic map. Numerical experiments show that the perturbed Baker map can achieve good statistical and cryptographic properties. Furthermore, a new image encryption algorithm is provided as a simple application. With a rather simple algorithm, the encrypted image can achieve high security, which is competitive to the recently proposed image encryption algorithms.

  1. Baker’s yeasts for use in frozen-dough technology : sugar utilization in freeze tolerant Torulaspora delbrueckii strains and elucidation of cryo-resistance mechanisms

    OpenAIRE

    Pacheco, Andreia

    2009-01-01

    Tese de doutoramento em Ciências (ramo de conhecimento em Biologia) Bread is a central dietary item in most countries of the world. Currently, frozen dough technology is extensively used in the baking industry to supply oven-fresh bakery products to consumers and to improve labor conditions for bakers. Since freeze–thaw stress affects the viability and activity of yeast cells, one serious disadvantage of this technology is a significant reduction in leavening activity during fr...

  2. New mutations affecting induced mutagenesis in yeast.

    Science.gov (United States)

    Lawrence, C W; Krauss, B R; Christensen, R B

    1985-01-01

    Previously isolated mutations in baker's yeast, Saccharomyces cerevisiae, that impair induced mutagenesis were all identified with the aid of tests that either exclusively or predominantly detect base-pair substitutions. To avoid this bias, we have screened 11 366 potentially mutant clones for UV-induced reversion of the frameshift allele, his4-38, and have identified 10 mutants that give much reduced yields of revertants. Complementation and recombination tests show that 6 of these carry mutations at the previously known REV1, REV1 and REV3 loci, while the remaining 4 define 3 new genes, REV4 (2 mutations), REV5 and REV6. The rev4 mutations are readily suppressed in many genetic backgrounds and, like the rev5 mutation, impart only a limited deficiency for induced mutagenesis: it is likely, therefore that the REV4+ and REV5+ gene functions are only remotely concerned with this process. The rev6 mutants have a more general deficiency, however, as well as marked sensitivity to UV and an increased spontaneous mutation rate, properties that suggest the REV6 gene is directly involved in mutation induction. The REV5 gene is located about 1 cM proximal to CYC1 on chromosome X.

  3. A generalization of Baker's quadratic formulae for hyperelliptic p-functions

    International Nuclear Information System (INIS)

    Athorne, Chris

    2011-01-01

    We present a generalization of a compact form, due to Baker, for quadratic identities satisfied by the three-index p-functions on curves of genus g=2, and a further generalization of a new result in genus g=3. The compact forms involve a bordered determinant containing 2(g-1)(g+1) free parameters. -- Highlights: → Properties of Weierstrass P-functions for hyperelliptic curves. → Generalization of result of H.F. Baker for genus two case. → Compact formulae with maximal number of parameters in genus two and three cases.

  4. Ultrasound guided percutaneous treatment and follow-up of Baker's cyst in knee osteoarthritis

    Energy Technology Data Exchange (ETDEWEB)

    Koeroglu, Mert, E-mail: mertkoroglu@hotmail.com [Antalya Education and Research Hospital, Department of Radiology, Antalya (Turkey); Call Latin-Small-Letter-Dotless-I oglu, Mehmet, E-mail: mehmetcallioglu@hotmail.com [Sueleyman Demirel University, Faculty of Medicine, Department of Radiology, Isparta (Turkey); Eris, Hueseyin Naim, E-mail: drhneris@hotmail.com [Sueleyman Demirel University, Faculty of Medicine, Department of Radiology, Isparta (Turkey); Kayan, Mustafa, E-mail: drkayan32@hotmail.com [Sueleyman Demirel University, Faculty of Medicine, Department of Radiology, Isparta (Turkey); Cetin, Meltem, E-mail: meltemcetin2011@yahoo.com [Sueleyman Demirel University, Faculty of Medicine, Department of Radiology, Isparta (Turkey); Yener, Mahmut, E-mail: bahtiyaryener@yahoo.com [Sueleyman Demirel University, Faculty of Medicine, Department of Physical Medicine and Rehabilitation, Isparta (Turkey); Guerses, Cemil, E-mail: cemilgurses@gmail.com [Antalya Education and Research Hospital, Department of Radiology, Antalya (Turkey); Erol, Bekir, E-mail: mertkoroglu@hotmail.com [Antalya Education and Research Hospital, Department of Radiology, Antalya (Turkey); Tuerkbey, Bar Latin-Small-Letter-Dotless-I s, E-mail: bturkbey@yahoo.com [Hacettepe University, Faculty of Medicine, Department of Radiology, Ankara (Turkey); Parlak, Ayse Eda, E-mail: drteda@yahoo.com [Antalya Education and Research Hospital, Department of Radiology, Antalya (Turkey); Akhan, Okan, E-mail: akhano@tr.net [Hacettepe University, Faculty of Medicine, Department of Radiology, Ankara (Turkey)

    2012-11-15

    Objective: Purpose of this study is to assess sonographic changes and clinical response in different subgroups of Baker's cyst patients with knee osteoarthritis after a single session of ultrasound-guided percutaneous aspiration and corticosteroid injection. Materials and methods: Thirty-two knee osteoarthritis patients (46-85 years, mean 58.97 {+-} 9.88) with symptomatic Baker's cyst diagnosed at ultrasonography were included in the study. To determine the grade of the symptoms, Visual Analogue Scale was applied. The patients were grouped in two, as simple (n = 24) and complex (n = 8) Baker's cyst. Thirty-two ultrasound-guided cyst aspirations concomitant 1 ml betamethasone injection (24 simple, 8 complex subgroups) were performed. Patients were followed clinically as well as via ultrasonography for 6 months after procedures. Results: A significant decrease in volume of the Baker's cysts after percutaneous treatment was accompanied by a significant clinical improvement. Moreover, the volume reduction of Baker's cyst after the treatment was significantly correlated with the clinical improvement (Pearson correlation coefficient = 0.542, p = 0.001). All 6 Baker's cysts relapsed at ultrasonography were complex type. Furthermore, a comparison of patients with simple Baker's cysts and those with complex Baker's cysts demonstrated no significant change in Visual Analogue Scale scores between two groups (p = 0.061, Mann-Whitney U). No complications (minor or major) occurred secondary to percutaneous treatment. Conclusion: Baker's cysts can be grouped as simple and complex groups via ultrasonography prior to the treatment. Cyst aspiration with ultrasound-guided corticosteroid injection yields clinical improvement and cyst volume reduction in all subgroups of patients with Baker's cyst secondary to knee osteoarthritis.

  5. Erisipelóide de Baker-Rosenbach

    Directory of Open Access Journals (Sweden)

    Aureo Guimarães de Macedo

    1970-10-01

    Full Text Available O erisipelóide de Baker-Rosenbach, embora assinalado no Brasil há 23, anos, por Sebastião Sampaio, seguido de nove casos estudados em 1951 por Lacaz e Ancona Lopes, não tem sido motivo de publicações posteriores. O A. teve ocasião de estudar seis casos, senão que três foram motivo de trabalho anterior e foram observados em 1953. Os três restantes, um de 1965 e dois de 1967, são aqui relatados. Assinala o A. a ubiquidade do germe, o Erysipelotrix rhusiopathiae e a variedade de condições em que o homem pode infectar-se, especialmente no exercício de determinadas profissões, o que dá à doença, caráter típico de doença profissional. São os operários de fábricas de botões ou em geral os que lidam com ossos, especialmente de porco ou carneiro, os açougueiros, magarefes, salsicheiros etc. São particularmente vulneráveis os que tratam com produtos do mar, pescadores, mercadores de siris, camarões, crustáceos, peixes em geral, pela facilidade com que se podem ferir e adquirir a infecção por picada ocasional. A doença atinge numerosos animais domésticos ou não, com formas clínicas bem definidas no porco (erisipela dos porcos, no carneiro (poliartrite dos carneiros, em animais de corte e de tração, em aves domésticas ou de rapina, ratos e camundongos, além de outros numerosos roedores. Moscas hematófagas e outros insetos têm sido encontrados infectados. Nunca é demais frisar que os produtos do mar são grande fonte de infecção humana. No homem, tem a dcença em geral, caráter benigno e localizado (erisipelóide, podendo em certas circunstâncias assumir característica septicêmica como no porco, produzir endocardite, como no carneiro além de outras formas clínicas e complicações. São resumidos no texto os três casos anteriormente apresentados e bem descritos os três inéditos, que têm história clínica e evolução típicas de erisipelóide. Tratando-se de doença com características tipicamente

  6. Analysis of the Involvement of Different Ceramide Variants in the Response to Hydroxyurea Stress in Baker's Yeast.

    Directory of Open Access Journals (Sweden)

    Po-Wei Chen

    Full Text Available Sphingolipids have been identified as important signaling compounds in stress responses. However, it is not always clear how different sphingolipid profiles are achieved in a particular stress situation. Here we propose a detailed mass action model, containing 42 dependent variables and 137 reactions, that offers explanations of the roles of variant ceramides species, which differ in the lengths of their fatty acyl chains and their saturation state, in the response to hydroxyurea stress. The simulations demonstrate that the cells manage to achieve hydroxyurea tolerance through a well-coordinated, differential usage of the variant ceramide species. Moreover, the results suggest that key enzymes have different affinities toward saturated and unsaturated fatty acyl chains, which implies that the saturation state affords the cells with an additional mode of regulation that had not been recognized so far. These conclusions from our computational analysis are yet to be validated experimentally.

  7. Simultaneous wastewater treatment and biogas production using integrated anaerobic baffled reactor granular activated carbon from baker's yeast wastewater.

    Science.gov (United States)

    Pirsaheb, Meghdad; Mohamadi, Samira; Rahmatabadi, Sama; Hossini, Hooshyar; Motteran, Fabrício

    2017-08-30

    In this study, simultaneous degradation of organic matter and color removal from food processing industries wastewater using an integrated anaerobic baffled reactor granular activated carbon (IABRGAC) was investigated. Theretofore, effective parameters such as hydraulic retention time (HRT) and granular activated carbon (GAC) filling ratio were studied. The bioreactor was operated at 3, 4 and 5 d of HRT and GAC filling ratio of 20%, 35% and 50%. To analyze and optimize the independent operating variables, response surface methodology was applied. Operating condition was optimized for HRT (4 d) and GAC filling ratio (50%). Better COD (94.6%) and BOD (93.7%) removal efficiency occurred with loading COD of 15,000 mg/L, with diminished wastewater color around 54% and turbidity to 54 NTU. In addition, methane production, methane yielding rate (Y m ) and specific methanogenic activity (SMA) test in an integrated system were investigated. The system IABRGAC was able to generate a volumetric rate about 0.31 and 0.44 L/g COD removed d at the experimental condition. The Y m was between 0.31 and 0.44 L/g COD removed .d and SMA was between 0.13 and 0.38 g COD/g volatile suspended solid. Based on results it can be concluded that the IABRGAC to be a successful pretreatment for highstrength wastewater before discharging the final effluent to sewerage and aerobic treating processes.

  8. A vibrating membrane bioreactor operated at supra- and sub-critical flux: Influence of extracellular polymeric substances from yeast cells

    DEFF Research Database (Denmark)

    Beier, Søren Prip; Jonsson, Gunnar Eigil

    2007-01-01

    A vibrating membrane bioreactor, in which the fouling problems are reduced by vibrating a hollow fiber membrane module, has been tested in constant flux microfiltration above (supra-critical) and below (sub-critical) an experimentally determined critical flux. Suspensions of bakers yeast cells were...... chosen as filtration medium (dry weight 4 g/l). The influence of extracellular polymeric substances (EPS) from the yeast cells is evaluated by UV absorbance measurements of the bulk supernatant during filtration. The critical flux seems to be an interval or a relative value rather than an absolute value....... Filtration just below the critical flux (sub-critical) seems to be a good compromise between acceptable flux level and acceptable increase of fouling resistance and trans-membrane pressure (TMP) in a given time period. EPS from the yeast cells causes the membrane module to foul and part of the fouling...

  9. Yang--Mills gauge theories and Baker--Johnson quantum electrodynamics

    International Nuclear Information System (INIS)

    Lemmon, J.; Mahanthappa, K.T.

    1976-01-01

    We show that the physical mass of a fermion in a symmetric asymptotically free non-Abelian vector gauge theory is dynamical in origin. We comment on the close analogy that exists between such a theory and the Baker--Johnson finite quantum electrodynamics. Comments are also made when there is spontaneous symmetry breaking

  10. Astragalus kongrensis Benth. Ex Baker (Fabaceae, a New Record for Central and North-West Himalayas

    Directory of Open Access Journals (Sweden)

    Lal Babu Chaudhary

    2006-09-01

    Full Text Available Astragalus kongrensis Benth. Ex Baker is reported for the first time from Central (Nepal and North-West Himalayas (India. Earlier the species was known from East Himalaya (Sikkim-India, Bhutan and China. The description and illustrations of the species are provided.

  11. On a parametrization of Baker-Campbell-Hausdorf formula for bosonic superfields in Lie algebra

    International Nuclear Information System (INIS)

    Gabeskiria, M.A.

    1984-01-01

    A compact form for the Baker-Cambell-Hausdorf formula has been obtained. Here the dependence of bosonic superfields, with their values on the Crassmann hull G(LAMBDA 2 ) of Lie algebra G, on the generators LAMBDA 2 has been factorized as a single exponent

  12. Electronically Transmitted Threats and Higher Education: Oppression, Free Speech, and Jake Baker

    Science.gov (United States)

    Schroeder, Jared C.

    2013-01-01

    When Jake Baker wrote a violent, sexually themed story about one of his classmates and emailed it to a friend, the case that ensued highlighted how new technologies have created fresh ways for students to harass, oppress, or be oppressed by others. This article examines concepts of violence and cultural imperialism oppression, primarily as defined…

  13. 77 FR 39675 - Wallowa-Whitman National Forest, Baker County, OR; North Fork Burnt River Mining

    Science.gov (United States)

    2012-07-05

    ...-Whitman National Forest, Baker County, OR; North Fork Burnt River Mining AGENCY: Forest Service, USDA... North Fork Burnt River Mining Record of Decision will replace and supercede the 2004 North Fork Burnt River Mining Record of Decision only where necessary to address the inadequacies identified by the court...

  14. Reconstructing streamflow variation of the Baker River from tree-rings in Northern Patagonia since 1765

    Science.gov (United States)

    Lara, Antonio; Bahamondez, Alejandra; González-Reyes, Alvaro; Muñoz, Ariel A.; Cuq, Emilio; Ruiz-Gómez, Carolina

    2015-10-01

    The understanding of the long-term variation of large rivers streamflow with a high economic and social relevance is necessary in order to improve the planning and management of water resources in different regions of the world. The Baker River has the highest mean discharge of those draining both slopes of the Andes South of 20°S and it is among the six rivers with the highest mean streamflow in the Pacific domain of South America (1100 m3 s-1 at its outlet). It drains an international basin of 29,000 km2 shared by Chile and Argentina and has a high ecologic and economic value including conservation, tourism, recreational fishing, and projected hydropower. This study reconstructs the austral summer - early fall (January-April) streamflow for the Baker River from Nothofagus pumilio tree-rings for the period 1765-2004. Summer streamflow represents 45.2% of the annual discharge. The regression model for the period (1961-2004) explains 54% of the variance of the Baker River streamflow (R2adj = 0.54). The most significant temporal pattern in the record is the sustained decline since the 1980s (τ = -0.633, p = 1.0144 ∗ 10-5 for the 1985-2004 period), which is unprecedented since 1765. The Correlation of the Baker streamflow with the November-April observed Southern Annular Mode (SAM) is significant (1961-2004, r = -0.55, p < 0.001). The Baker record is also correlated with the available SAM tree-ring reconstruction based on other species when both series are filtered with a 25-year spline and detrended (1765-2004, r = -0.41, p < 0.01), emphasizing SAM as the main climatic forcing of the Baker streamflow. Three of the five summers with the highest streamflow in the entire reconstructed record occurred after the 1950s (1977, 1958 and 1959). The causes of this high streamflow events are not yet clear and cannot be associated with the reported recent increase in the frequency of glacial-lake outburst floods (GLOFs). The decreasing trend in the observed and reconstructed

  15. Yeast genome sequencing:

    DEFF Research Database (Denmark)

    Piskur, Jure; Langkjær, Rikke Breinhold

    2004-01-01

    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...... 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...

  16. Beer and bread to brains and beyond: can yeast cells teach us about neurodegenerative disease?

    Science.gov (United States)

    Gitler, Aaron D

    2008-01-01

    For millennia, humans have harnessed the astonishing power of yeast, producing such culinary masterpieces as bread, beer and wine. Therefore, in this new millennium, is it very farfetched to ask if we can also use yeast to unlock some of the modern day mysteries of human disease? Remarkably, these seemingly simple cells possess most of the same basic cellular machinery as the neurons in the brain. We and others have been using the baker's yeast, Saccharomyces cerevisiae, as a model system to study the mechanisms of devastating neurodegenerative diseases such as Parkinson's, Huntington's, Alzheimer's and amyotrophic lateral sclerosis. While very different in their pathophysiology, they are collectively referred to as protein-misfolding disorders because of the presence of misfolded and aggregated forms of various proteins in the brains of affected individuals. Using yeast genetics and the latest high-throughput screening technologies, we have identified some of the potential causes underpinning these disorders and discovered conserved genes that have proven effective in preventing neuron loss in animal models. Thus, these genes represent new potential drug targets. In this review, I highlight recent work investigating mechanisms of cellular toxicity in a yeast Parkinson's disease model and discuss how similar approaches are being applied to additional neurodegenerative diseases.

  17. Breeding of Freeze-tolerant Yeast and the Mechanisms of Stress-tolerance

    Science.gov (United States)

    Hino, Akihiro

    Frozen dough method have been adopted in the baking industry to reduce labor and to produce fresh breads in stores. New freeze-tolerant yeasts for frozen dough preparations were isolated from banana peel and identified. To obtain strains that have fermentative ability even after several months of frozen storage in fermented dough, we attempted to breed new freeze-tolerantstrain. The hybrid between S.cerevisiae, which is a isolated freeze-tolerant strain, and a strain isolated from bakers' yeast with sexual conjugation gave a good quality bread made from frozen dough method. Freeze-tolerant strains showed higher surviving and trehalose accumulating abilities than freeze-sensitive strains. The freeze tolerance of the yeasts was associated with the basal amount of intracellular trehalose after rapid degradation at the onset of the prefermentation period. The complicated metabolic pathway and the regulation system of trehalose in yeast cells are introduced. The trehalose synthesis may act as a metabolic buffer system which contribute to maintain the intracellular inorganic phosphate and as a feedback regulation system in the glycolysis. However, it is not known enough how the trehalose protects yeast cells from stress.

  18. Evolution of the hemiascomycete yeasts: on life styles and the importance of inbreeding.

    Science.gov (United States)

    Knop, Michael

    2006-07-01

    The term 'breeding system' is used to describe the morphological and behavioural aspects of the sexual life cycle of a species. The yeast breeding system provides three alternatives that enable hapoids to return to the diploid state that is necessary for meiosis: mating of unrelated haploids (amphimixis), mating between spores from the same tetrad (intratetrad mating, automixis) and mother daughter mating upon mating type switching (haplo-selfing). The frequency of specific mating events affects the level of heterozygosity present in individuals and the genetic diversity of populations. This review discusses the reproductive strategies of yeasts, in particular S. cerevisiae (Bakers' or budding yeast). Emphasis is put on intratetrad mating, its implication for diversity, and how the particular genome structure could have evolved to ensure the preservation of a high degree of heterozygosity in conjunction with frequent intratetrad matings. I also discuss how the ability of yeast to control the number of spores that are formed accounts for high intratetrad mating rates and for enhanced transmission of genomic variation. I extend the discussion to natural genetic variation and propose that a high level of plasticity is inherent in the yeast breeding system, which may allow variation of the breeding behaviour in accordance with the needs imposed by the environment. (c) 2006 Wiley Periodicals, Inc.

  19. 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

  20. Some contrasting biostratigraphic links between the Baker and Olds Ferry Terranes, eastern Oregon

    Science.gov (United States)

    Nestell, Merlynd K.; Blome, Charles D.

    2016-01-01

    New stratigraphic and paleontologic data indicate that ophiolitic melange windows in the Olds Ferry terrane of eastern Oregon contain limestone blocks and chert that are somewhat different in age than those present in the adjacent Baker terrane melange. The melange windows in the Olds Ferry terrane occur as inliers in the flyschoid Early and Middle Jurassic age Weatherby Formation, which depositionally overlies the contact between the melange-rich Devonian to Upper Triassic rocks of the Baker terrane on the north, and Upper Triassic and Early Jurassic volcanic arc rocks of the Huntington Formation on the south. The Baker terrane and Huntington Formation represent fragments of a subduction complex and related volcanic island arc, whereas the Weatherby Formation consists of forearc basin sedimentary deposits. The tectonic blocks in the melange windows of the Weatherby Formation (in the Olds Ferry terrane) are dated by scarce biostratigraphic evidence as Upper Pennsylvanian to Lower Permian and Upper Triassic. In contrast, tectonic blocks of limestone in theBaker terrane yield mostly fusulinids and small foraminifers of Middle Pennsylvanian Moscovian age at one locality.Middle Permian (Guadalupian) Tethyan fusulinids and smaller foraminifers (neoschwagerinids and other Middle Permian genera) are present at a few other localities. Late Triassic conodonts and bryozoans are also present in a few of the Baker terrane tectonic blocks. These limestone blocks are generally embedded in Permian and Triassic radiolarian bearing chert or argillite. Based on conodont, radiolarian and fusulinid data, the age limits of the meange blocks in the Weatherby Formation range from Pennsylvanian to Late Triassic.

  1. Transcriptional reprogramming in yeast using dCas9 and combinatorial gRNA strategies

    DEFF Research Database (Denmark)

    Damgaard Jensen, Emil; Ferreira, Raphael; Jakociunas, Tadas

    2017-01-01

    on developing synthetic biology tools for orthogonal control of transcription. Most recently, the nuclease-deficient Cas9 (dCas9) has emerged as a flexible tool for controlling activation and repression of target genes, by the simple RNA-guided positioning of dCas9 in the vicinity of the target gene...... transcription start site. In this study we compared two different systems of dCas9-mediated transcriptional reprogramming, and applied them to genes controlling two biosynthetic pathways for biobased production of isoprenoids and triacylglycerols (TAGs) in baker's yeast Saccharomyces cerevisiae. By testing 101...... production and increases in TAG. Taken together, we show similar performance for a constitutive and an inducible dCas9 approach, and identify multiplex gRNA designs that can significantly perturb isoprenoid production and TAG profiles in yeast without editing the genomic context of the target genes. We also...

  2. Application of synthetic biology for production of chemicals in yeast Saccharomyces cerevisiae

    DEFF Research Database (Denmark)

    Borodina, Irina; Li, Mingji

    2015-01-01

    Synthetic biology and metabolic engineering enable generation of novel cell factories that efficiently convert renewable feedstocks into biofuels, bulk, and fine chemicals, thus creating the basis for biosustainable economy independent on fossil resources. While over a hundred proof...... biology has the potential to bring down this cost by improving our ability to predictably engineer biological systems. This review highlights synthetic biology applications for design, assembly, and optimization of non-native biochemical pathways in baker's yeast Saccharomyces cerevisiae. We describe......-of-concept chemicals have been made in yeast, only a very small fraction of those has reached commercial-scale production so far. The limiting factor is the high research cost associated with the development of a robust cell factory that can produce the desired chemical at high titer, rate, and yield. Synthetic...

  3. Allergy in bakers' apprentices and factors associated to non-participation in a cohort study of allergic sensitization

    DEFF Research Database (Denmark)

    Skjold, Tina; Nielsen, Sven C; Adolf, Katja

    2006-01-01

    Objective  To describe the prevalence of atopy and respiratory symptoms among baker apprentices at the start of the education and factors associated with non-participation in the study. Methods  A total of 346 students, 22.1(0.6) years of age, mean (SD), from the food production programme...... of atopy in bakers' apprentices was of the same magnitude in the general Danish population. Significantly, more male bakers' apprentices had atopy. This finding has major impact on the diagnostic procedures of occupational allergy in bakery workers emphasizing the need for standardization of the clinical...

  4. The indentation of pressurized elastic shells: from polymeric capsules to yeast cells

    KAUST Repository

    Vella, D.

    2011-08-10

    Pressurized elastic capsules arise at scales ranging from the 10 m diameter pressure vessels used to store propane at oil refineries to the microscopic polymeric capsules that may be used in drug delivery. Nature also makes extensive use of pressurized elastic capsules: plant cells, bacteria and fungi have stiff walls, which are subject to an internal turgor pressure. Here, we present theoretical, numerical and experimental investigations of the indentation of a linearly elastic shell subject to a constant internal pressure. We show that, unlike unpressurized shells, the relationship between force and displacement demonstrates two linear regimes. We determine analytical expressions for the effective stiffness in each of these regimes in terms of the material properties of the shell and the pressure difference. As a consequence, a single indentation experiment over a range of displacements may be used as a simple assay to determine both the internal pressure and elastic properties of capsules. Our results are relevant for determining the internal pressure in bacterial, fungal or plant cells. As an illustration of this, we apply our results to recent measurements of the stiffness of baker\\'s yeast and infer from these experiments that the internal osmotic pressure of yeast cells may be regulated in response to changes in the osmotic pressure of the external medium.

  5. The genome of wine yeast Dekkera bruxellensis provides a tool to explore its food-related properties

    Energy Technology Data Exchange (ETDEWEB)

    Piskur, Jure; Ling, Zhihao; Marcet-Houben, Marina; Ishchuk, Olena P.; Aerts, Andrea; LaButti, Kurt; Copeland, Alex; Lindquist, Erika; Barry, Kerrie; Compagno, Concetta; Bisson, Linda; Grigoriev, Igor V.; Gabaldon, Toni; Phister, Trevor

    2012-03-14

    The yeast Dekkera/Brettanomyces bruxellensis can cause enormous economic losses in wine industry due to production of phenolic off-flavor compounds. D. bruxellensis is a distant relative of baker's yeast Saccharomyces cerevisiae. Nevertheless, these two yeasts are often found in the same habitats and share several food-related traits, such as production of high ethanol levels and ability to grow without oxygen. In some food products, like lambic beer, D. bruxellensis can importantly contribute to flavor development. We determined the 13.4 Mb genome sequence of the D. bruxellensis strain Y879 (CBS2499) and deduced the genetic background of several ?food-relevant? properties and evolutionary history of this yeast. Surprisingly, we find that this yeast is phylogenetically distant to other food-related yeasts and most related to Pichia (Komagataella) pastoris, which is an aerobic poor ethanol producer. We further show that the D. bruxellensis genome does not contain an excess of lineage specific duplicated genes nor a horizontally transferred URA1 gene, two crucial events that promoted the evolution of the food relevant traits in the S. cerevisiae lineage. However, D. bruxellensis has several independently duplicated ADH and ADH-like genes, which are likely responsible for metabolism of alcohols, including ethanol, and also a range of aromatic compounds.

  6. An enquiry into the prevalence of musculoskeletal disorders and ergonomic risk factors among Hamadan-based bakers in 2017

    Directory of Open Access Journals (Sweden)

    Majid Motamedzade Torghabeh

    2018-01-01

    Conclusion: Musculoskeletal disorders of the knees, the middle and lower back, shoulders and wrists are of a high prevalence among bakers of traditional bread. Therefore, both engineering and management interventions are recommended to eliminate musculoskeletal disorders.

  7. CRED 5 m Gridded bathymetry of Baker Island, Pacific Remote Island Areas, Central Pacific (Arc ASCII Format)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Gridded (5 m cell size) bathymetry of the shelf and slope environments of Baker Island, Pacific Remote Isand Areas, Central Pacific. Almost complete bottom coverage...

  8. Racial science in social context: John R. Baker on eugenics, race, and the public role of the scientist.

    Science.gov (United States)

    Kenny, Michael G

    2004-09-01

    In 1974 a British biologist, John Randal Baker (1900-1984), published a large and controversial book simply entitled Race that reiterated persistent eugenicist themes concerning the relation between race, intelligence, and progress. The history of Baker's book is a case study in the politics of scientific publishing, and his ideas influenced scholars associated with later works such as The Bell Curve. Baker, a student of Julian Huxley, was a longtime participant in the British eugenics movement and opponent of what he took to be a facile belief in human equality. In 1942, together with Michael Polanyi, he founded the Society for Freedom in Science to oppose those who advocated the central planning of scientific research. Baker's eugenics, political activities, and views on race express an elitist individualism, associated with the conservative wing of the eugenics movement, that this paper explores in the context of his career as a whole.

  9. CRED 40 m Gridded bathymetry of Baker Island, Pacific Remote Island Areas, Central Pacific (Arc ASCII Format)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Gridded (40 m cell size) bathymetry of the shelf and slope environments of Baker Island, Pacific Remote Island Areas, Central Pacific. Almost complete bottom...

  10. Topics in noncommutative algebra the theorem of Campbell, Baker, Hausdorff and Dynkin

    CERN Document Server

    Bonfiglioli, Andrea

    2012-01-01

    Motivated by the importance of the Campbell, Baker, Hausdorff, Dynkin Theorem in many different branches of Mathematics and Physics (Lie group-Lie algebra theory, linear PDEs, Quantum and Statistical Mechanics, Numerical Analysis, Theoretical Physics, Control Theory, sub-Riemannian Geometry), this monograph is intended to: 1) fully enable readers (graduates or specialists, mathematicians, physicists or applied scientists, acquainted with Algebra or not) to understand and apply the statements and numerous corollaries of the main result; 2) provide a wide spectrum of proofs from the modern literature, comparing different techniques and furnishing a unifying point of view and notation; 3) provide a thorough historical background of the results, together with unknown facts about the effective early contributions by Schur, Poincaré, Pascal, Campbell, Baker, Hausdorff and Dynkin; 4) give an outlook on the applications, especially in Differential Geometry (Lie group theory) and Analysis (PDEs of subelliptic type); ...

  11. Assessment of increased thermal activity at Mount Baker, Washington, March 1975-March 1976

    Science.gov (United States)

    Frank, David; Meier, Mark Frederick; Swanson, Donald A.; with contributions by Babcock, James W.; Fretwell, Marvin O.; Malone, Stephen D.; Rosenfeld, Charles L.; Shreve, Ronald L.; Wilcox, Ray E.

    1977-01-01

    In March 1975 Mount Baker showed a large increase in thermal emission, which has persisted for more than 1 year. Fumarole ejecta accompanied the thermal activity from March to September, but the ejecta had no constituents that suggest a magmatic source. Estimates of that part of the total heat flux that would account for the observed snow and ice loss show that the heat-flow increase was roughly one order of magnitude, from about 2 megawatts at 10 watts per square meter, averaged over Sherman Crater before 1975, to about 30 megawatts at 180 watts per square meter, during 1975. Almost half of the glacier that occupied the basin of Sherman Crater was melted in 1975. The new activity generated great concern among the public and the government agencies responsible for geological evaluation of potential hazards and for protection of life and property. The past geologic history, current topography, rock alteration, and location of major fumarolic activity indicate that large rock avalanches and mudflows on the east slope in Boulder Creek valley are the potential hazards of most significance related to present conditions. The most probable types of large mass movements would be mudflows, having speeds of as much as 50 kilometers per hour, that would originate from mixtures of snow, ice, and melt water and avalanches of structurally weak clay-rich rocks that make up the rim of Sherman Crater. Similar mudflows from the volcano have traveled at least 12 kilometers 8 times during the past 10,000 years. A possible worst case event, however, might be a larger, air-cushioned avalanche of as much as 20 to 30 million cubic meters that could hit Baker Lake at speeds of more than 300 kilometers per hour and generate a wave of water large enough to overtop Upper Baker Dam. At least 30 million cubic meters of potentially unstable material occurs as hydrothermally altered remnants of the rim of Sherman Crater and could provide the required volume for the estimated worst case event or

  12. 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.

  13. Furoquinoline Alkaloids and Methoxyflavones from the Stem Bark of Melicope madagascariensis (Baker T.G. Hartley

    Directory of Open Access Journals (Sweden)

    Vincent E. Rasamison

    2016-09-01

    Full Text Available Abstract Melicope madagascariensis (Rutaceae is an endemic plant species of Madagascar that was first classified as a member of the genus Euodia J. R. & G. Forst (Rutaceae under the scientific name Euodia madagascariensis Baker. Based on morphological characteristics, Thomas Gordon Hartley taxonomically revised E. madagascariensis Baker to be M. madagascariensis (Baker T.G. Hartley. Chemotaxonomical studies have long been used to help the identification and confirmation of taxonomical classification of plant species and botanicals. Aiming to find more evidences to support the taxonomical revision performed on E. madagascariensis, we carried out phytochemical investigation of two samples of the plant. Fractionation of the ethanol extracts prepared from two stem bark samples of M. madagascariensis (Baker T.G. Hartley led to the isolation of seven known furoquinoline alkaloids 1–7 and two known methoxyflavones 8 and 9. The presence of furoquinoline alkaloids and methoxyflavones in the title species is in agreement with its taxonomic transfer from Euodia to Melicope. Antiprotozoal evaluation of the isolated compounds showed that 6-methoxy-7-hydroxydictamnine (heliparvifoline, 3 showed weak antimalarial activity (IC50 = 35 µM against the chloroquine-resistant strain Dd2 of Plasmodium falciparum. Skimmianine (4 displayed moderate cytotoxicity with IC50 value of 1.5 µM against HT-29 colon cancer cell line whereas 3,5-dihydroxy-3′,4′,7-trimethoxyflavone (9 was weakly active in the same assay (IC50 = 13.9 µM. Graphical Abstract

  14. A new term in the recursive expansion of the inverse Baker-Campbell-Hausdorff formula

    International Nuclear Information System (INIS)

    Riccardi, A.

    1984-01-01

    A recursive algorithm is derived, allowing the expansion in lambda of z=exp(x+lambda y) for noncommuting x and y, written as ordered product of exponentials. Such an expansion is the inverse of the usual Baker-Campbell-Hausdorff formula. The explicit form of the terms, up to third order in lambda is also given. The same method provides the explicit expansion to any order for the matrix elements of z

  15. 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##

  16. Lung cancer risk among bakers, pastry cooks and confectionary makers: the SYNERGY study.

    Science.gov (United States)

    Behrens, Thomas; Kendzia, Benjamin; Treppmann, Tabea; Olsson, Ann; Jöckel, Karl-Heinz; Gustavsson, Per; Pohlabeln, Hermann; Ahrens, Wolfgang; Brüske, Irene; Wichmann, Hans-Erich; Merletti, Franco; Mirabelli, Dario; Richiardi, Lorenzo; Simonato, Lorenzo; Zaridze, David; Szeszenia-Dabrowska, Neonila; Rudnai, Peter; Lissowska, Jolanta; Fabianova, Eleonora; Tardón, Adonina; Field, John; Stanescu Dumitru, Rodica; Bencko, Vladimir; Foretova, Lenka; Janout, Vladimir; Siemiatycki, Jack; Parent, Marie-Elise; McLaughlin, John; Demers, Paul; Landi, Maria Teresa; Caporaso, Neil; Kromhout, Hans; Vermeulen, Roel; Peters, Susan; Benhamou, Simone; Stücker, Isabelle; Guida, Florence; Consonni, Dario; Bueno-de-Mesquita, Bas; 't Mannetje, Andrea; Pearce, Neil; Tse, Lap Ah; Yu, Ignatius Tak-sun; Plato, Nils; Boffetta, Paolo; Straif, Kurt; Schüz, Joachim; Pesch, Beate; Brüning, Thomas

    2013-11-01

    Some studies have suggested increased lung cancer risks among bakers, however the results overall were inconsistent. The authors studied lung cancer risks among bakers and baking-related occupations in the SYNERGY pooled case-control database from 16 countries. Occupation in a baking-related job was identified from the subjects' job histories. ORs adjusted for log(age), study centre, smoking behaviour and ever employment in a job with known exposure to occupational lung carcinogens were calculated by unconditional logistic regression. Findings were stratified by sex, histological subtype of lung cancer and smoking status. 19 366 cases (15 606 men) and 23 670 control subjects (18 528 men) were included. 473 cases (415 men, 58 women) and 501 controls (437 men, 64 women) had ever worked in baking or a related job. We did not observe an increased risk for men in baking (OR 1.01; 95% CI 0.86 to 1.18). No linear trends were observed for duration of employment. Some results suggested increased lung cancer risks for women, for example, for working as a baker for >30 years and in never-smokers, but after exclusion of one study these increased risks disappeared. The findings from this study do not suggest increased lung cancer risks in baking-related professions.

  17. Yeast as a system for modeling mitochondrial disease mechanisms and discovering therapies

    Directory of Open Access Journals (Sweden)

    Jean-Paul Lasserre

    2015-06-01

    Full Text Available Mitochondrial diseases are severe and largely untreatable. Owing to the many essential processes carried out by mitochondria and the complex cellular systems that support these processes, these diseases are diverse, pleiotropic, and challenging to study. Much of our current understanding of mitochondrial function and dysfunction comes from studies in the baker's yeast Saccharomyces cerevisiae. Because of its good fermenting capacity, S. cerevisiae can survive mutations that inactivate oxidative phosphorylation, has the ability to tolerate the complete loss of mitochondrial DNA (a property referred to as ‘petite-positivity’, and is amenable to mitochondrial and nuclear genome manipulation. These attributes make it an excellent model system for studying and resolving the molecular basis of numerous mitochondrial diseases. Here, we review the invaluable insights this model organism has yielded about diseases caused by mitochondrial dysfunction, which ranges from primary defects in oxidative phosphorylation to metabolic disorders, as well as dysfunctions in maintaining the genome or in the dynamics of mitochondria. Owing to the high level of functional conservation between yeast and human mitochondrial genes, several yeast species have been instrumental in revealing the molecular mechanisms of pathogenic human mitochondrial gene mutations. Importantly, such insights have pointed to potential therapeutic targets, as have genetic and chemical screens using yeast.

  18. Yeast Infection during Pregnancy

    Science.gov (United States)

    ... disrupt the pH balance of the vagina. Common yeast infection symptoms include vaginal itching and a white, thick discharge that looks ... and Prevention. http://www.cdc.gov/std/tg2015/candidiasis.htm. Accessed Aug. 27, ... Vagina, Cervix, Toxic Shock Syndrome, Endometritis, and Salpingitis. In: ...

  19. Polysome Profile Analysis - Yeast

    Czech Academy of Sciences Publication Activity Database

    Pospíšek, M.; Valášek, Leoš Shivaya

    2013-01-01

    Roč. 530, č. 2013 (2013), s. 173-181 ISSN 0076-6879 Institutional support: RVO:61388971 Keywords : grow yeast cultures * polysome profile analysis * sucrose density gradient centrifugation Subject RIV: CE - Biochemistry Impact factor: 2.194, year: 2013

  20. Transcriptional robustness and protein interactions are associated in yeast

    Directory of Open Access Journals (Sweden)

    Conant Gavin C

    2011-05-01

    Full Text Available Abstract Background Robustness to insults, both external and internal, is a characteristic feature of life. One level of biological organization for which noise and robustness have been extensively studied is gene expression. Cells have a variety of mechanisms for buffering noise in gene expression, but it is not completely clear what rules govern whether or not a given gene uses such tools to maintain appropriate expression. Results Here, we show a general association between the degree to which yeast cells have evolved mechanisms to buffer changes in gene expression and whether they possess protein-protein interactions. We argue that this effect bears an affinity to epistasis, because yeast appears to have evolved regulatory mechanisms such that distant changes in gene copy number for a protein-protein interaction partner gene can alter a gene's expression. This association is not unexpected given recent work linking epistasis and the deleterious effects of changes in gene dosage (i.e., the dosage balance hypothesis. Using gene expression data from artificial aneuploid strains of bakers' yeast, we found that genes coding for proteins that physically interact with other proteins show less expression variation in response to aneuploidy than do other genes. This effect is even more pronounced for genes whose products interact with proteins encoded on aneuploid chromosomes. We further found that genes targeted by transcription factors encoded on aneuploid chromosomes were more likely to change in expression after aneuploidy. Conclusions We suggest that these observations can be best understood as resulting from the higher fitness cost of misexpression in epistatic genes and a commensurate greater regulatory control of them.

  1. 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.

  2. 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.

  3. Production of liquid transport fuel from cellulose material (wood). III Laboratory preparation of wood sugars and fermentation to ethanol and yeast

    Energy Technology Data Exchange (ETDEWEB)

    Whitworth, D A; Harwood, V D

    1977-10-25

    A laboratory procedure is described for hydrolyzing cellulose material to sugars by the use of hot sulfuric acid. The procedure has been used routinely for assessing raw materials. Raw materials used were radiata pine (fresh wood and decayed thinnings), pine needles, sawdust from old dumps, newspaper, cardboard, beech wood, and coconut wood. The neutralized sugar-liquors produced, supplemented with fertilizer grade nutrients, were fermented with bakers' yeast and gave near optimal conversion of hexoses to ethanol and of pentoses to protein biomass. From 100 g radiata pine (wood: bark mix 85:15) 25 ml (20 g) of ethanol and 2 g yeast biomass were routinely produced, although fermentation rates were lower than with pure sugars. The results, however, clearly showed that, by a hot dilute sulfure acid hydrolysis followed by a yeast fermentation process, cellulose resources avaliable in New Zealand are suitable for conversion to ethanol. 5 table, 1 figure.

  4. Degradation of spent craft brewer's yeast by caprine rumen hyper ammonia-producing bacteria.

    Science.gov (United States)

    Harlow, B E; Bryant, R W; Cohen, S D; O'Connell, S P; Flythe, M D

    2016-10-01

    Spent yeast from craft beers often includes more hops (Humulus lupulus L.) secondary metabolites than traditional recipes. These compounds include α- and β- acids, which are antimicrobial to the rumen hyper ammonia-producing bacteria (HAB) that are major contributors to amino acid degradation. The objective was to determine if the hops acids in spent craft brewer's yeast (CY; ~ 3·5 mg g(-1) hops acids) would protect it from degradation by caprine rumen bacteria and HAB when compared to a baker's yeast (BY; no hops acids). Cell suspensions were prepared by harvesting rumen fluid from fistulated goats, straining and differential centrifugation. The cells were re-suspended in media with BY or CY. After 24 h (39°C), HAB were enumerated and ammonia was measured. Fewer HAB and less ammonia was produced from CY than from BY. Pure culture experiments were conducted with Peptostreptococcus anaerobiusBG1 (caprine HAB). Ammonia production by BG1 from BY was greater than from CY. Ammonia production was greater when exogenous amino acids were included, but similar inhibition was observed in CY treatments. These results indicate that rumen micro-organisms deaminated the amino acids in CY to a lesser degree than BY. Spent brewer's yeast has long been included in ruminant diets as a protein supplement. However, modern craft beers often include more hops (Humulus lupulus L.) than traditional recipes. These compounds include α- and β- acids, which are antimicrobial to the rumen hyper ammonia-producing bacteria (HAB) that are major contributors to amino acid degradation. This study demonstrated that hops acids in spent craft brewer's yeast protected protein from destruction by HABin vitro. These results suggest that the spent yeast from craft breweries, a source of beneficial hops secondary metabolites, could have value as rumen-protected protein. Published 2016. This article is a U.S. Government work and is in the public domain in the USA.

  5. A study on the fundamental mechanism and the evolutionary driving forces behind aerobic fermentation in yeast.

    Science.gov (United States)

    Hagman, Arne; Piškur, Jure

    2015-01-01

    Baker's yeast Saccharomyces cerevisiae rapidly converts sugars to ethanol and carbon dioxide at both anaerobic and aerobic conditions. The later phenomenon is called Crabtree effect and has been described in two forms, long-term and short-term effect. We have previously studied under fully controlled aerobic conditions forty yeast species for their central carbon metabolism and the presence of long-term Crabtree effect. We have also studied ten steady-state yeast cultures, pulsed them with glucose, and followed the central carbon metabolism and the appearance of ethanol at dynamic conditions. In this paper we analyzed those wet laboratory data to elucidate possible mechanisms that determine the fate of glucose in different yeast species that cover approximately 250 million years of evolutionary history. We determine overflow metabolism to be the fundamental mechanism behind both long- and short-term Crabtree effect, which originated approximately 125-150 million years ago in the Saccharomyces lineage. The "invention" of overflow metabolism was the first step in the evolution of aerobic fermentation in yeast. It provides a general strategy to increase energy production rates, which we show is positively correlated to growth. The "invention" of overflow has also simultaneously enabled rapid glucose consumption in yeast, which is a trait that could have been selected for, to "starve" competitors in nature. We also show that glucose repression of respiration is confined mainly among S. cerevisiae and closely related species that diverged after the whole genome duplication event, less than 100 million years ago. Thus, glucose repression of respiration was apparently "invented" as a second step to further increase overflow and ethanol production, to inhibit growth of other microbes. The driving force behind the initial evolutionary steps was most likely competition with other microbes to faster consume and convert sugar into biomass, in niches that were semi-anaerobic.

  6. A study on the fundamental mechanism and the evolutionary driving forces behind aerobic fermentation in yeast.

    Directory of Open Access Journals (Sweden)

    Arne Hagman

    Full Text Available Baker's yeast Saccharomyces cerevisiae rapidly converts sugars to ethanol and carbon dioxide at both anaerobic and aerobic conditions. The later phenomenon is called Crabtree effect and has been described in two forms, long-term and short-term effect. We have previously studied under fully controlled aerobic conditions forty yeast species for their central carbon metabolism and the presence of long-term Crabtree effect. We have also studied ten steady-state yeast cultures, pulsed them with glucose, and followed the central carbon metabolism and the appearance of ethanol at dynamic conditions. In this paper we analyzed those wet laboratory data to elucidate possible mechanisms that determine the fate of glucose in different yeast species that cover approximately 250 million years of evolutionary history. We determine overflow metabolism to be the fundamental mechanism behind both long- and short-term Crabtree effect, which originated approximately 125-150 million years ago in the Saccharomyces lineage. The "invention" of overflow metabolism was the first step in the evolution of aerobic fermentation in yeast. It provides a general strategy to increase energy production rates, which we show is positively correlated to growth. The "invention" of overflow has also simultaneously enabled rapid glucose consumption in yeast, which is a trait that could have been selected for, to "starve" competitors in nature. We also show that glucose repression of respiration is confined mainly among S. cerevisiae and closely related species that diverged after the whole genome duplication event, less than 100 million years ago. Thus, glucose repression of respiration was apparently "invented" as a second step to further increase overflow and ethanol production, to inhibit growth of other microbes. The driving force behind the initial evolutionary steps was most likely competition with other microbes to faster consume and convert sugar into biomass, in niches that

  7. Development of industrial yeast for second generation bioethanol production

    Energy Technology Data Exchange (ETDEWEB)

    Hou, X

    2012-01-15

    The cost of lignocellulose-based bioethanol needs to be reduced, in order to commercialize this clean and sustainable fuel substitute for fossil fuels. A microorganism that can completely and efficiently convert all the sugars in lignocellulose into ethanol is one of the prerequisites of a cost-effective production process. In addition, the microorganisms should also have a high tolerance towards the inhibitory compounds present in the lignocellulosic hydrolysate, which are formed during the pretreatment of lignocellulose. Baker's yeast, Saccharomyces cerevisiae, is generally regarded as a robust microorganism and can efficiently ferment glucose. But it lacks the ability to ferment xylose which comprises 20-35% of lignocellulose. Naturally xylose-fermenting yeast such as Pichia stipitis is much more sensitive to inhibitors than S. cerevisiae and it requires accurately controlled microaerophilic conditions during the xylose fermentation, rendering the process technically difficult and expensive. In this study, a novel xylose fermenting yeast Spathaspora passalidarum displayed fast cell growth and efficient xylose fermentation under anaerobic conditions. In contrast, P. stipitis was almost unable to utilize xylose under the same conditions. It is further demonstrated that S. passalidarum converts xylose by means of NADH-preferred xylose reductase (XR) and NAD+-dependent xylitol dehydrogenase (XDH). Thus, the capacity of S. passalidarum to utilize xylose under anaerobic conditions is possibly due to a balance between supply and demand of cofactor through this XR-XDH pathway. Only one other XR with NADH preference has been reported so far. Unfortunately, S. passalidarum also has a low tolerance towards inhibitors generated during pretreatment, which prevents immediate use of this yeast in industrial application. S. passalidarum is able to convert the inhibitor furfural to furfuryl alcohol in a synthetic medium when the addition of furfural is low. The enzymes involved

  8. Development of industrial yeast for second generation bioethanol production

    Energy Technology Data Exchange (ETDEWEB)

    Hou, X.

    2012-01-15

    The cost of lignocellulose-based bioethanol needs to be reduced, in order to commercialize this clean and sustainable fuel substitute for fossil fuels. A microorganism that can completely and efficiently convert all the sugars in lignocellulose into ethanol is one of the prerequisites of a cost-effective production process. In addition, the microorganisms should also have a high tolerance towards the inhibitory compounds present in the lignocellulosic hydrolysate, which are formed during the pretreatment of lignocellulose. Baker's yeast, Saccharomyces cerevisiae, is generally regarded as a robust microorganism and can efficiently ferment glucose. But it lacks the ability to ferment xylose which comprises 20-35% of lignocellulose. Naturally xylose-fermenting yeast such as Pichia stipitis is much more sensitive to inhibitors than S. cerevisiae and it requires accurately controlled microaerophilic conditions during the xylose fermentation, rendering the process technically difficult and expensive. In this study, a novel xylose fermenting yeast Spathaspora passalidarum displayed fast cell growth and efficient xylose fermentation under anaerobic conditions. In contrast, P. stipitis was almost unable to utilize xylose under the same conditions. It is further demonstrated that S. passalidarum converts xylose by means of NADH-preferred xylose reductase (XR) and NAD+-dependent xylitol dehydrogenase (XDH). Thus, the capacity of S. passalidarum to utilize xylose under anaerobic conditions is possibly due to a balance between supply and demand of cofactor through this XR-XDH pathway. Only one other XR with NADH preference has been reported so far. Unfortunately, S. passalidarum also has a low tolerance towards inhibitors generated during pretreatment, which prevents immediate use of this yeast in industrial application. S. passalidarum is able to convert the inhibitor furfural to furfuryl alcohol in a synthetic medium when the addition of furfural is low. The enzymes

  9. Alpha-ketoglutarate enhances freeze-thaw tolerance and prevents carbohydrate-induced cell death of the yeast Saccharomyces cerevisiae.

    Science.gov (United States)

    Bayliak, Maria M; Hrynkiv, Olha V; Knyhynytska, Roksolana V; Lushchak, Volodymyr I

    2018-01-01

    Stress resistance and fermentative capability are important quality characteristics of baker's yeast. In the present study, we examined protective effects of exogenous alpha-ketoglutarate (AKG), an intermediate of the tricarboxylic acid cycle and amino acid metabolism, against freeze-thaw and carbohydrate-induced stresses in the yeast Saccharomyces cerevisiae. Growth on AKG-supplemented medium prevented a loss of viability and improved fermentative capacity of yeast cells after freeze-thaw treatment. The cells grown in the presence of AKG had higher levels of amino acids (e.g., proline), higher metabolic activity and total antioxidant capacity, and higher activities of catalase, NADP-dependent glutamate dehydrogenase and glutamine synthase compared to control ones. Both synthesis of amino acids and enhancement of antioxidant system capacity could be involved in AKG-improved freeze-thaw tolerance in S. cerevisiae. Cell viability dramatically decreased under incubation of stationary-phase yeast cells in 2% glucose or fructose solutions (in the absence of the other nutrients) as compared with incubation in distilled water or in 10 mM AKG solution. The decrease in cell viability was accompanied by acidification of the medium, and decrease in cellular respiration, aconitase activity, and levels of total protein and free amino acids. The supplementation with 10 mM AKG effectively prevented carbohydrate-induced yeast death. Protective mechanisms of AKG could be associated with the intensification of respiration and prevention of decreasing protein level as well as with direct antioxidant AKG action.

  10. Yeast glycolipid biosurfactants.

    Science.gov (United States)

    Jezierska, Sylwia; Claus, Silke; Van Bogaert, Inge

    2017-10-25

    Various yeasts, both conventional and exotic ones, are known to produce compounds useful to mankind. Ethanol is the most known of these compounds, but more complex molecules such as amphiphilic biosurfactants can also be derived from eukaryotic microorganisms at an industrially and commercially relevant scale. Among them, glycolipids are the most promising, due to their attractive properties and high product titers. Many of these compounds can be considered as secondary metabolites with a specific function for the host. Hence, a dedicated biosynthetic process enables regulation and combines pathways delivering the lipidic moiety and the hydrophilic carbohydrate part of the glycolipid. In this Review, we will discuss the biosynthetic and regulatory aspects of the yeast-derived sophorolipids, mannosylerythritol lipids, and cellobiose lipids, with special emphasis on the relation between glycolipid synthesis and the general lipid metabolism. © 2017 Federation of European Biochemical Societies.

  11. Genetically engineered yeast

    DEFF Research Database (Denmark)

    2014-01-01

    A genetically modified Saccharomyces cerevisiae comprising an active fermentation pathway producing 3-HP expresses an exogenous gene expressing the aminotransferase YhxA from Bacillus cereus AH1272 catalysing a transamination reaction between beta-alanine and pyruvate to produce malonate semialde......A genetically modified Saccharomyces cerevisiae comprising an active fermentation pathway producing 3-HP expresses an exogenous gene expressing the aminotransferase YhxA from Bacillus cereus AH1272 catalysing a transamination reaction between beta-alanine and pyruvate to produce malonate...... semialdehyde. The yeast may also express a 3-hydroxyisobutyrate dehydrogenase (HIBADH) and a 3-hydroxypropanoate dehydrogenase (3-HPDH) and aspartate 1-decarboxylase. Additionally the yeast may express pyruvate carboxylase and aspartate aminotransferase....

  12. 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/m 2 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.

  13. Tapping into yeast diversity.

    Science.gov (United States)

    Fay, Justin C

    2012-11-01

    Domesticated organisms demonstrate our capacity to influence wild species but also provide us with the opportunity to understand rapid evolution in the context of substantially altered environments and novel selective pressures. Recent advances in genetics and genomics have brought unprecedented insights into the domestication of many organisms and have opened new avenues for further improvements to be made. Yet, our ability to engineer biological systems is not without limits; genetic manipulation is often quite difficult. The budding yeast, Saccharomyces cerevisiae, is not only one of the most powerful model organisms, but is also the premier producer of fermented foods and beverages around the globe. As a model system, it entertains a hefty workforce dedicated to deciphering its genome and the function it encodes at a rich mechanistic level. As a producer, it is used to make leavened bread, and dozens of different alcoholic beverages, such as beer and wine. Yet, applying the awesome power of yeast genetics to understanding its origins and evolution requires some knowledge of its wild ancestors and the environments from which they were derived. A number of surprisingly diverse lineages of S. cerevisiae from both primeval and secondary forests in China have been discovered by Wang and his colleagues. These lineages substantially expand our knowledge of wild yeast diversity and will be a boon to elucidating the ecology, evolution and domestication of this academic and industrial workhorse.

  14. Helicopter magnetic and electromagnetic surveys at Mounts Adams, Baker and Rainier, Washington: implications for debris flow hazards and volcano hydrology

    Science.gov (United States)

    Finn, Carol A.; Deszcz-Pan, Maria

    2011-01-01

    High‐resolution helicopter magnetic and electromagnetic (HEM) data flown over the rugged, ice‐covered Mt. Adams, Mt. Baker and Mt. Rainier volcanoes (Washington), reveal the distribution of alteration, water and ice thickness essential to evaluating volcanic landslide hazards. These data, combined with geological mapping and rock property measurements, indicate the presence of appreciable thicknesses (>500 m) of water‐saturated hydrothermally altered rock west of the modern summit of Mount Rainier in the Sunset Amphitheater region and in the central core of Mount Adams north of the summit. Alteration at Mount Baker is restricted to thinner (<300 m) zones beneath Sherman Crater and the Dorr Fumarole Fields. The EM data identified water‐saturated rocks from the surface to the detection limit (100–200 m) in discreet zones at Mt. Rainier and Mt Adams and over the entire summit region at Mt. Baker. The best estimates for ice thickness are obtained over relatively low resistivity (<800 ohm‐m) ground for the main ice cap on Mt. Adams and over most of the summit of Mt. Baker. The modeled distribution of alteration, pore fluids and partial ice volumes on the volcanoes helps identify likely sources for future alteration‐related debris flows, including the Sunset Amphitheater region at Mt. Rainier, steep cliffs at the western edge of the central altered zone at Mount Adams and eastern flanks of Mt. Baker.

  15. 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......) and receptor/signal processing. A few basic similarities are common to both fission and budding yeasts. The wiring of the regulatory circuitry, however, varies considerably between these divergent yeast groups....

  16. Entropy analysis in yeast DNA

    International Nuclear Information System (INIS)

    Kim, Jongkwang; Kim, Sowun; Lee, Kunsang; Kwon, Younghun

    2009-01-01

    In this article, we investigate the language structure in yeast 16 chromosomes. In order to find it, we use the entropy analysis for codons (or amino acids) of yeast 16 chromosomes, developed in analysis of natural language by Montemurro et al. From the analysis, we can see that there exists a language structure in codons (or amino acids) of yeast 16 chromosomes. Also we find that the grammar structure of amino acids of yeast 16 chromosomes has a deep relationship with secondary structure of protein.

  17. Genomics and the making of yeast biodiversity

    NARCIS (Netherlands)

    Hittinger, Chris Todd; Rokas, Antonis; Bai, Feng-Yan; Boekhout, Teun; Gonçalves, Paula; Jeffries, Thomas W; Kominek, Jacek; Lachance, Marc-André; Libkind, Diego; Rosa, Carlos A; Sampaio, José Paulo; Kurtzman, Cletus P

    2015-01-01

    Yeasts are unicellular fungi that do not form fruiting bodies. Although the yeast lifestyle has evolved multiple times, most known species belong to the subphylum Saccharomycotina (syn. Hemiascomycota, hereafter yeasts). This diverse group includes the premier eukaryotic model system, Saccharomyces

  18. Current awareness on yeast.

    Science.gov (United States)

    2002-02-01

    In order to keep subscribers up-to-date with the latest developments in their field, this current awareness service is provided by John Wiley & Sons and contains newly-published material on yeasts. Each bibliography is divided into 10 sections. 1 Books, Reviews & Symposia; 2 General; 3 Biochemistry; 4 Biotechnology; 5 Cell Biology; 6 Gene Expression; 7 Genetics; 8 Physiology; 9 Medical Mycology; 10 Recombinant DNA Technology. Within each section, articles are listed in alphabetical order with respect to author. If, in the preceding period, no publications are located relevant to any one of these headings, that section will be omitted. (3 weeks journals - search completed 5th. Dec. 2001)

  19. W. Ritchie Russell, A.B. Baker, and Fred Plum: Pioneers of ventilatory management in poliomyelitis.

    Science.gov (United States)

    Wijdicks, Eelco F M

    2016-09-13

    Historically, neurologists were not involved in the day-to-day management of critically ill patients with bulbar poliomyelitis, but some were. The major contributions of 3 neurologists-W. Ritchie Russell, A.B. Baker, and Fred Plum-in the respiratory management of poliomyelitis have not been recognized. Russell's work was instrumental in identifying multiple types of poliomyelitis defined by their respiratory needs, and he advised treatment that varied from simple postural drainage to use of respirators. He participated in the development of the Radcliffe respiratory pump. Baker recognized the essential involvement of the vagal nerve in respiratory distress, but also observed that involvement of vital centers without cranial nerve involvement would lead to irregular and shallow respiration in some patients and in others with marked dysautonomic features. A similar finding of central involvement of respiration was noted by Plum, who also stressed the importance of hypercapnia. Plum emphasized measurements of vital capacity and techniques to minimize trauma with suctioning after tracheostomy. These 3 neurologists understood the importance of airway and ventilator management, which is currently one of the many pillars of neurocritical care. © 2016 American Academy of Neurology.

  20. [Respiratory allergies among symptomatic bakers and pastry cooks: initial results of a prevalence study].

    Science.gov (United States)

    Bataille, A; Anton, M; Mollat, F; Bobe, M; Bonneau, C; Caramaniam, M N; Géraut, C; Dupas, D

    1995-01-01

    A survey was carried out on respiratory symptoms and skin prick response to common allergens, storage mite and occupational allergens. Among 178 symptomatics bakers and pastry workers from small businesses in western France, only 65 people underwent skin prick and specific-IgE. 12 (18%) workers were skin positive to at least one common or occupational allergens. The more often skin positive were D. Ptero. mite 36 (57%); Alpha amylase 23 (35%); wheat flour 17 (26%); saccharomyces cerevisiae 16 (25%); Ephestia 15 (24%). The sensitivity of skin test was better than specific IgE for D. Ptero. Mite 36 (57%); and Alpha amylase 23 (35%). The sensitivity of specific IgE was better than skin test for wheat flour 26 (45%) and rye flour 23 (40%). Occurrence of skin positive to occupational allergen among symptomatics with rhinitis and asthma is much more frequent in workers with skin positive to common allergens (40/36) than in workers with skin negative (8/20). Atopy must be regarded as an important predisposing factor for skin sensitisation to occupational allergens. We conclude in the necessity of a standardised allergologic exploration to be done in symptomatics bakers.

  1. A novel image encryption scheme based on the ergodicity of baker map

    Science.gov (United States)

    Ye, Ruisong; Chen, Yonghong

    2012-01-01

    Thanks to the exceptionally good properties in chaotic systems, such as sensitivity to initial conditions and control parameters, pseudo-randomness and ergodicity, chaos-based image encryption algorithms have been widely studied and developed in recent years. A novel digital image encryption scheme based on the chaotic ergodicity of Baker map is proposed in this paper. Different from traditional encryption schemes based on Baker map, we permute the pixel positions by their corresponding order numbers deriving from the approximating points in one chaotic orbit. To enhance the resistance to statistical and differential attacks, a diffusion process is suggested as well in the proposed scheme. The proposed scheme enlarges the key space significantly to resist brute-force attack. Additionally, the distribution of gray values in the cipher-image has a random-like behavior to resist statistical analysis. The proposed scheme is robust against cropping, tampering and noising attacks as well. It therefore suggests a high secure and efficient way for real-time image encryption and transmission in practice.

  2. Magma at depth: A retrospective analysis of the 1975 unrest at Mount Baker, Washington, USA

    Science.gov (United States)

    Crider, Juliet G.; Frank, David; Malone, Stephen D.; Poland, Michael P.; Werner, Cynthia; Caplan-Auerbach, Jacqueline

    2011-01-01

    Mount Baker volcano displayed a short interval of seismically-quiescent thermal unrest in 1975, with high emissions of magmatic gas that slowly waned during the following three decades. The area of snow-free ground in the active crater has not returned to pre-unrest levels, and fumarole gas geochemistry shows a decreasing magmatic signature over that same interval. A relative microgravity survey revealed a substantial gravity increase in the ~30 years since the unrest, while deformation measurements suggest slight deflation of the edifice between 1981-83 and 2006-07. The volcano remains seismically quiet with regard to impulsive volcano-tectonic events, but experiences shallow (10 km) long-period earthquakes. Reviewing the observations from the 1975 unrest in combination with geophysical and geochemical data collected in the decades that followed, we infer that elevated gas and thermal emissions at Mount Baker in 1975 resulted from magmatic activity beneath the volcano: either the emplacement of magma at mid-crustal levels, or opening of a conduit to a deep existing source of magmatic volatiles. Decadal-timescale, multi-parameter observations were essential to this assessment of magmatic activity.

  3. Yeast biomass production: a new approach in glucose-limited feeding strategy

    Directory of Open Access Journals (Sweden)

    Érika Durão Vieira

    2013-01-01

    Full Text Available The aim of this work was to implement experimentally a simple glucose-limited feeding strategy for yeast biomass production in a bubble column reactor based on a spreadsheet simulator suitable for industrial application. In biomass production process using Saccharomyces cerevisiae strains, one of the constraints is the strong tendency of these species to metabolize sugars anaerobically due to catabolite repression, leading to low values of biomass yield on substrate. The usual strategy to control this metabolic tendency is the use of a fed-batch process in which where the sugar source is fed incrementally and total sugar concentration in broth is maintained below a determined value. The simulator presented in this work was developed to control molasses feeding on the basis of a simple theoretical model in which has taken into account the nutritional growth needs of yeast cell and two input data: the theoretical specific growth rate and initial cell biomass. In experimental assay, a commercial baker's yeast strain and molasses as sugar source were used. Experimental results showed an overall biomass yield on substrate of 0.33, a biomass increase of 6.4 fold and a specific growth rate of 0.165 h-1 in contrast to the predicted value of 0.180 h-1 in the second stage simulation.

  4. The expression of glycerol facilitators from various yeast species improves growth on glycerol of Saccharomyces cerevisiae

    Directory of Open Access Journals (Sweden)

    Mathias Klein

    2016-12-01

    Full Text Available Glycerol is an abundant by-product during biodiesel production and additionally has several assets compared to sugars when used as a carbon source for growing microorganisms in the context of biotechnological applications. However, most strains of the platform production organism Saccharomyces cerevisiae grow poorly in synthetic glycerol medium. It has been hypothesized that the uptake of glycerol could be a major bottleneck for the utilization of glycerol in S. cerevisiae. This species exclusively relies on an active transport system for glycerol uptake. This work demonstrates that the expression of predicted glycerol facilitators (Fps1 homologues from superior glycerol-utilizing yeast species such as Pachysolen tannophilus, Komagataella pastoris, Yarrowia lipolytica and Cyberlindnera jadinii significantly improves the growth performance on glycerol of the previously selected glycerol-consuming S. cerevisiae wild-type strain (CBS 6412-13A. The maximum specific growth rate increased from 0.13 up to 0.18 h−1 and a biomass yield coefficient of 0.56 gDW/gglycerol was observed. These results pave the way for exploiting the assets of glycerol in the production of fuels, chemicals and pharmaceuticals based on baker's yeast. Keywords: Yeast, Saccharomyces cerevisiae, Glycerol, Transport, Glycerol facilitator, Fps1, Stl1

  5. Towards the design of an optimal strategy for the production of ergosterol from Saccharomyces cerevisiae yeasts.

    Science.gov (United States)

    Náhlík, Jan; Hrnčiřík, Pavel; Mareš, Jan; Rychtera, Mojmír; Kent, Christopher A

    2017-05-01

    The total yield of ergosterol produced by the fermentation of the yeast Saccharomyces cerevisiae depends on the final amount of yeast biomass and the ergosterol content in the cells. At the same time ergosterol purity-defined as percentage of ergosterol in the total sterols in the yeast-is equally important for efficient downstream processing. This study investigated the development of both the ergosterol content and ergosterol purity in different physiological (metabolic) states of the microorganism S. cerevisiae with the aim of reaching maximal ergosterol productivity. To expose the yeast culture to different physiological states during fermentation an on-line inference of the current physiological state of the culture was used. The results achieved made it possible to design a new production strategy, which consists of two preferable metabolic states, oxidative-fermentative growth on glucose followed by oxidative growth on glucose and ethanol simultaneously. Experimental application of this strategy achieved a value of the total efficiency of ergosterol production (defined as product of ergosterol yield coefficient and volumetric productivity), 103.84 × 10 -6 g L -1 h -1 , more than three times higher than with standard baker's yeast fed-batch cultivations, which attained in average 32.14 × 10 -6 g L -1 h -1 . At the same time the final content of ergosterol in dry biomass was 2.43%, with a purity 86%. These results make the product obtained by the proposed control strategy suitable for effective down-stream processing. © 2017 American Institute of Chemical Engineers Biotechnol. Prog., 33:838-848, 2017. © 2017 American Institute of Chemical Engineers.

  6. Effects of yeasts and bacteria on the levels of folates in rye sourdoughs.

    Science.gov (United States)

    Kariluoto, Susanna; Aittamaa, Marja; Korhola, Matti; Salovaara, Hannu; Vahteristo, Liisa; Piironen, Vieno

    2006-02-01

    Fermentation of rye dough is often accompanied with an increase in folate content. In this study, three sourdough yeasts, Candida milleri CBS 8195, Saccharomyces cerevisiae TS 146, and Torulaspora delbrueckii TS 207; a control, baker's yeast S. cerevisiae ALKO 743; and four Lactobacillus spp., L. acidophilus TSB 262, L. brevis TSB 307, L. plantarum TSB 304, and L. sanfranciscensis TSB 299 originally isolated from rye sourdough were examined for their abilities to produce or consume folates. The microorganisms were grown in yeast extract-peptone-d-glucose medium as well as in small-scale fermentations that modelled the sourdough fermentation step used in rye baking. Total folate contents were determined using Lactobacillus rhamnosus (ATCC 7469) as the growth indicator organism. The microorganisms studied did not excrete folates into the media in significant amounts. Yeasts increased the folate contents of sterilised rye flour-water mixtures from 6.5 microg/100 g to between 15 and 23 microg/100 g after 19-h fermentation, whereas lactic acid bacteria decreased it to between 2.9 and 4.2 microg/100 g. Strains of Lactobacillus bulgaricus, L. casei, L. curvatus, L. fermentum, L. helveticus, Pediococcus spp., and Streptococcus thermophilus that were also tested gave folate contents after fermentation that varied between 2 and 10.4 microg/100 g. Although the four Lactobacillus spp. from sourdough consumed folates their effect on folate contents in co-cultivations was minimal. It was concluded that the increase of folate content during fermentation was mainly due to folate synthesis by yeasts. Fermentation of non-sterilised flour-water mixtures as such resulted in three-fold increases in the folate contents. Two folate producing bacteria were isolated from the non-sterilised flour and identified as Enterobacter cowanii and Pantoea agglomerans.

  7. Apoptosis and pro-death autophagy induced by a spirostanol saponin isolated from Rohdea chinensis (Baker) N. Tanaka (synonym Tupistra chinensis Baker) on HL-60 cells.

    Science.gov (United States)

    Yi, Xiaomin; Xiang, Limin; Huang, Yuying; Wang, Yihai; He, Xiangjiu

    2018-03-15

    Our previous study has revealed that the spirostanol saponins isolated from the rhizomes of Rohdea chinensis (Baker) N. Tanaka (synonym Tupistra chinensis Baker) (Convallariaceae) (a reputed folk medicine) exhibited potent antiproliferative activity. However, the underlying mechanism of purified saponins remains unclear. More studies are necessary to assess the apoptosis and autophagy activities of the saponins from R. chinensis and clarify their antiproliferative mechanisms. The present study certificated the potential antiproliferative activity and mechanism of 5β-spirost-25(27)-en-1β,3β-diol-1-O-α-L-rhamnopyranosyl-(1→2)- β-D-xylopyranosyl-3-O-α-L-rhamnopyranoside (SPD), a spirostanol saponin from R. chinensis, against human acute promyelocytic leukemia cells (HL-60). The antiproliferative activity of SPD in vitro was evaluated by MTT assay compared with cis-dichlorodiammineplatinum (II). The autophagic activity was assessed using MDC staining and western blot, cell apoptosis inspection was detected by Annexin V-FITC/PI double staining and the mitochondrial membrane potential was detected by JC-1 fluorescence dye combined with flow cytometry. The potential mechanisms for protein levels of apoptosis and autophagy were evaluated by western blot. Treatment of HL-60 cells with SPD resulted in growth inhibition (IC 50 value of 2.0 ± 0.2 µM, after 48 h treatment) and induction of apoptosis and autophagy. Results from Annexin V-FITC/PI double-staining assay and mitochondrial membrane potential detection showed that apoptosis was happened after SPD treatment. The regulation of caspase-3, Bax, Bcl-2, PARP following SPD treatment contributed to the induction of mitochondria-dependent apoptosis. Meanwhile, SPD induced autophagy related with Akt/mTOR/p70S6K signaling and activated of AMPK signaling pathway. Furthermore, blocking autophagy with bafilomycin A1 reduced the cytotoxicity of SPD in HL-60 cells. The antiproliferative, apoptosis and pro

  8. 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...

  9. On the growth of scientific knowledge: yeast biology as a case study.

    Directory of Open Access Journals (Sweden)

    Xionglei He

    2009-03-01

    Full Text Available The tempo and mode of human knowledge expansion is an enduring yet poorly understood topic. Through a temporal network analysis of three decades of discoveries of protein interactions and genetic interactions in baker's yeast, we show that the growth of scientific knowledge is exponential over time and that important subjects tend to be studied earlier. However, expansions of different domains of knowledge are highly heterogeneous and episodic such that the temporal turnover of knowledge hubs is much greater than expected by chance. Familiar subjects are preferentially studied over new subjects, leading to a reduced pace of innovation. While research is increasingly done in teams, the number of discoveries per researcher is greater in smaller teams. These findings reveal collective human behaviors in scientific research and help design better strategies in future knowledge exploration.

  10. Mitochondrial modification and respiratory deficiency in the yeast cell caused by cadmium poisoning

    Energy Technology Data Exchange (ETDEWEB)

    Lindegren, C C; Lindegren, G

    1973-01-01

    Cells of Fleischmann bakers' yeast were grown in standard nutrient broth and in broth to which cobalt, or cadmium, or thallium, had been added. The cells were fixed by glutaraldehyde-permanganate and sectioned. Electron microscopy showed that (a) the endoplasmic reticulum was fixed well in cells grown in cobalt or cadmium, but the endoplasmic reticulum was not fixed in cells grown in normal or thallium broth; (b) the cristate mitochondria were normal in all cells except those grown in cadmium. No cristae were visible in the cristate mitochondria of cells grown in cadmium broth; (c) a large fraction of the cells recovered from cadmium broth were respiratory-deficient; (d) thallic oxide was present in the cristate mitochondria of cells recovered from thallium broth. 13 references, 3 figures.

  11. Omics Data Complementarity Underlines Functional Cross-Communication in Yeast.

    Science.gov (United States)

    Malod-Dognin, Noël; Pržulj, Nataša

    2017-06-10

    Mapping the complete functional layout of a cell and understanding the cross-talk between different processes are fundamental challenges. They elude us because of the incompleteness and noisiness of molecular data and because of the computational intractability of finding the exact answer. We perform a simple integration of three types of baker's yeast omics data to elucidate the functional organization and lines of cross-functional communication. We examine protein-protein interaction (PPI), co-expression (COEX) and genetic interaction (GI) data, and explore their relationship with the gold standard of functional organization, the Gene Ontology (GO). We utilize a simple framework that identifies functional cross-communication lines in each of the three data types, in GO, and collectively in the integrated model of the three omics data types; we present each of them in our new Functional Organization Map (FOM) model. We compare the FOMs of the three omics datasets with the FOM of GO and find that GI is in best agreement with GO, followed COEX and PPI. We integrate the three FOMs into a unified FOM and find that it is in better agreement with the FOM of GO than those of any omics dataset alone, demonstrating functional complementarity of different omics data.

  12. The mechanism of untargeted mutagenesis in UV-irradiated yeast.

    Science.gov (United States)

    Lawrence, C W; Christensen, R B

    1982-01-01

    The SOS error-prone repair hypothesis proposes that untargeted and targeted mutations in E. coli both result from the inhibition of polymerase functions that normally maintain fidelity, and that this is a necessary precondition for translesion synthesis. Using mating experiments with excision deficient strains of Bakers' yeast, Saccharomyces cerevisiae, we find that up to 40% of cycl-91 revertants induced by UV are untargeted, showing that a reduction in fidelity is also found in irradiated cells of this organism. We are, however, unable to detect the induction or activation of any diffusible factor capable of inhibiting fidelity, and therefore suggest that untargeted and targeted mutations are the consequence of largely different processes. We propose that these observations are best explained in terms of a limited fidelity model. Untargeted mutations are thought to result from the limited capacity of processes which normally maintain fidelity, which are active during replication on both irradiated and unirradiated templates. Even moderate UV fluences saturate this capacity, leading to competition for the limited resource. Targeted mutations are believed to result from the limited, though far from negligible, capacity of lesions like pyrimidine dimers to form Watson-Crick base pairs.

  13. The mechanism of untargeted mutagenesis in UV-irradiated yeast

    International Nuclear Information System (INIS)

    Lawrence, C.W.; Christensen, R.B.

    1982-01-01

    The SOS error-prone repair hypothesis proposes that untargeted and targeted mutations in E. coli both result from the inhibition of polymerase functions that normally maintain fidelity, and that this is a necessary precondition for translesion synthesis. Using mating experiments with excision deficient strains of Bakers' yeast, Saccharomyces cerevisiae, we find that up to 40% of cycl-91 revertants induced by UV are untargeted, showing that a reduction in fidelity is also found in irradiated cells of this organism. We are, however, unable to detect the induction or activation of any diffusible factor capable of inhibiting fidelity, and therefore suggest that untargeted and targeted mutations are the consequence of largely different processes. We propose that these observations are best explained in terms of a limited fidelity model. Untargeted mutations are thought to result from the limited capacity of processes which normally maintain fidelity, which are active during replication on both irradiated and unirradiated templates. Even moderate UV fluences saturate this capacity, leading to competition for the limited resource. Targeted mutations are believed to result from the limited, though far from negligible, capacity of lesions like pyrimidine dimers to form Watson-Crick base pairs. (orig.)

  14. 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

  15. 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.

  16. 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.

  17. Assessment and characterisation of yeast-based products intended to mitigate ochratoxin exposure using in vitro and in vivo models.

    Science.gov (United States)

    Pfohl-Leszkowicz, A; Hadjeba-Medjdoub, K; Ballet, N; Schrickx, J; Fink-Gremmels, J

    2015-01-01

    The aim of this paper was to evaluate the capacity of several yeast-based products, derived from baker's and brewer's yeasts, to sequester the mycotoxin ochratoxin A (OTA) and to decrease its rate of absorption and DNA adduct formation in vivo. The experimental protocol included in vitro binding studies using isotherm models, in vivo chicken experiments, in which the serum and tissue concentrations of OTA were analysed in the absence and presence of the test compounds, and the profile of OTA-derived metabolites and their associated DNA adducts were determined. Additionally in vitro cell culture studies (HK2 cells) were applied to assess further the effects for yeast cell product enriched with glutathione (GSH) or selenium. Results of the in vitro binding assay in a buffer system indicated the ability of the yeast-based products, as sequester of OTA, albeit at a different level. In the in vitro experiments in chickens, decreased serum and tissue concentrations of treated animals confirmed that yeast-based products are able to prevent the absorption of OTA. A comparison of the binding affinity in a standard in vitro binding assay with the results obtained in an in vivo chicken experiment, however, showed a poor correlation and resulted in a different ranking of the products. More importantly, we could show that yeast-based products actively modulate the biotransformation of OTA in vivo as well as in vitro in a cell culture model. This effect seems to be attributable to residual enzymatic activities in the yeast-based products. An enrichment of yeast cell wall products with GSH or selenium further modulated the profile of the generated OTA metabolites and the associated pattern of OTA-induced DNA adducts by increasing the conversion of OTA into less toxic metabolites such as OTA, OTB and 4-OH-OTA. A reduced absorption and DNA adduct formation was particularly observed with GSH-enriched yeast, whereas selenium-enriched yeasts could counteract the OTA-induced decrease

  18. High power density yeast catalyzed microbial fuel cells

    Science.gov (United States)

    Ganguli, Rahul

    Microbial fuel cells leverage whole cell biocatalysis to convert the energy stored in energy-rich renewable biomolecules such as sugar, directly to electrical energy at high efficiencies. Advantages of the process include ambient temperature operation, operation in natural streams such as wastewater without the need to clean electrodes, minimal balance-of-plant requirements compared to conventional fuel cells, and environmentally friendly operation. These make the technology very attractive as portable power sources and waste-to-energy converters. The principal problem facing the technology is the low power densities compared to other conventional portable power sources such as batteries and traditional fuel cells. In this work we examined the yeast catalyzed microbial fuel cell and developed methods to increase the power density from such fuel cells. A combination of cyclic voltammetry and optical absorption measurements were used to establish significant adsorption of electron mediators by the microbes. Mediator adsorption was demonstrated to be an important limitation in achieving high power densities in yeast-catalyzed microbial fuel cells. Specifically, the power densities are low for the length of time mediator adsorption continues to occur. Once the mediator adsorption stops, the power densities increase. Rotating disk chronoamperometry was used to extract reaction rate information, and a simple kinetic expression was developed for the current observed in the anodic half-cell. Since the rate expression showed that the current was directly related to microbe concentration close to the electrode, methods to increase cell mass attached to the anode was investigated. Electrically biased electrodes were demonstrated to develop biofilm-like layers of the Baker's yeast with a high concentration of cells directly connected to the electrode. The increased cell mass did increase the power density 2 times compared to a non biofilm fuel cell, but the power density

  19. Yeast "make-accumulate-consume" life strategy evolved as a multi-step process that predates the whole genome duplication.

    Science.gov (United States)

    Hagman, Arne; Säll, Torbjörn; Compagno, Concetta; Piskur, Jure

    2013-01-01

    When fruits ripen, microbial communities start a fierce competition for the freely available fruit sugars. Three yeast lineages, including baker's yeast Saccharomyces cerevisiae, have independently developed the metabolic activity to convert simple sugars into ethanol even under fully aerobic conditions. This fermentation capacity, named Crabtree effect, reduces the cell-biomass production but provides in nature a tool to out-compete other microorganisms. Here, we analyzed over forty Saccharomycetaceae yeasts, covering over 200 million years of the evolutionary history, for their carbon metabolism. The experiments were done under strictly controlled and uniform conditions, which has not been done before. We show that the origin of Crabtree effect in Saccharomycetaceae predates the whole genome duplication and became a settled metabolic trait after the split of the S. cerevisiae and Kluyveromyces lineages, and coincided with the origin of modern fruit bearing plants. Our results suggest that ethanol fermentation evolved progressively, involving several successive molecular events that have gradually remodeled the yeast carbon metabolism. While some of the final evolutionary events, like gene duplications of glucose transporters and glycolytic enzymes, have been deduced, the earliest molecular events initiating Crabtree effect are still to be determined.

  20. 75 FR 65263 - Virginia Graeme Baker Pool and Spa Safety Act; Public Accommodation; Withdrawal of Proposed Rule

    Science.gov (United States)

    2010-10-22

    ...'' or ``Act'') as ``an inn, hotel, motel, or other place of lodging, except for an establishment located... interpretive rule to interpret ``public accommodations facility'' in the VGB Act as ``an inn, hotel, motel, or... CONSUMER PRODUCT SAFETY COMMISSION 16 CFR Part 1450 Virginia Graeme Baker Pool and Spa Safety Act...

  1. Genetic study on yeast

    International Nuclear Information System (INIS)

    Mortimer, R.K.

    1981-01-01

    Research during the past year has moved ahead on several fronts. A major compilation of all the genetic mapping data for the yeast Saccharomyces cerevisiae has been completed. The map describes the location of over 300 genes on 17 chromosomes. A report on this work will appear in Microbiological Reviews in December 1980. Recombinant DNA procedures have been introduced into the experiments and RAD52 (one of the genes involved in recombination and repair damage), has been successfully cloned. This clone will be used to determine the gene product. Diploid cells homozygous for RAD52 have exceptionally high frequencies of mitotic loss of chromosomes. This loss is stimulated by ionizing radiation. This effect is a very significant finding. The effect has also been seen with certain other RAD mutants

  2. 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

  3. 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

  4. ERGONOMIC CONSIDERATION OF THE EFFECT OF FLOUR DUST ON PEAK EXPIRATORY FLOW RATE OF BAKERS IN ABEOKUTA, OGUN STATE

    Directory of Open Access Journals (Sweden)

    Adekunle Ibrahim MUSA

    2017-06-01

    Full Text Available Flour dusts are one of the most harmful chemicals in the bakery industries which could lead to serious heart and lung diseases. This study investigated the effect of flour dust on Peak Expiratory Flow Rate of male bakers in Abeokuta, Ogun State, Nigeria with the relationship to the anthropometrical parameters. A total of One hundred Eighty (180 male participants were investigated, where ninety (90 participants were bakers and ninety (90 individuals as control group. The Peak expiratory flow rate (PEFR and anthropometrical parameters of the participant were measured using mini-Wright peak flow meter (PFM 20, OMRON and Detecto PD300MDHR (Cardinal Scale manufacturing company, USA column scale with digital height rod was used to measure body mass [kg] and height (cm respectively. The PEFR and anthropometrical parameters of the bakers and control groups were analysed using descriptive statistics and T-test with SPSS. The results showed that lower PEFR, 182.67 ± 16.34 L/min existed in bakers compared to 287.67 ± 17.02 L/min in the control study. The result also showed that a significant correlation exist between body mass, height and age (P < 0.01, PEFR, height (P < 0.05 and years of exposure (P < 0.01 of the bakers respectively. Furthermore, the results also showed that workers in the dusting and mixing of flour are at a risk of developing related pulmonary function impairment such as asthma. The study concluded that there is need to develop an effective intervention strategy, treatment seeking behaviour through awareness programs to prevent lung impairment diseases among the bakery workers.

  5. Yeasts preservation: alternatives for lyophilisation

    OpenAIRE

    Nyanga, Loveness K.; Nout, Martinus J. R.; Smid, Eddy J.; Boekhout, Teun; Zwietering, Marcel 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 during 6 months storage at 4 and 25 °C. None of the yeast cultures showed a significant loss in viable cell count during 6 months of storage at 4 °C upon lyophilisation and preservation in dry rice cak...

  6. [Distiller Yeasts Producing Antibacterial Peptides].

    Science.gov (United States)

    Klyachko, E V; Morozkina, E V; Zaitchik, B Ts; Benevolensky, S V

    2015-01-01

    A new method of controlling lactic acid bacteria contamination was developed with the use of recombinant Saccharomyces cerevisiae strains producing antibacterial peptides. Genes encoding the antibacterial peptides pediocin and plantaricin with codons preferable for S. cerevisiae were synthesized, and a system was constructed for their secretory expression. Recombinant S. cerevisiae strains producing antibacterial peptides effectively inhibit the growth of Lactobacillus sakei, Pediacoccus pentasaceus, Pediacoccus acidilactici, etc. The application of distiller yeasts producing antibacterial peptides enhances the ethanol yield in cases of bacterial contamination. Recombinant yeasts producing the antibacterial peptides pediocin and plantaricin can successfully substitute the available industrial yeast strains upon ethanol production.

  7. I Teoremi di Campbell, Baker, Hausdorff e Dynkin. Storia, Prove, Problemi Aperti

    Directory of Open Access Journals (Sweden)

    Andrea Bonfiglioli

    2010-12-01

    Full Text Available The aim of this lecture is to provide an overview of facts and references about past and recent results on the Theorem of Campbell, Baker, Hausdorff and Dynkin (shortcut as the CBHD Theorem, following the recent preprint monograph [13]. In particular, we shall give sketches of the following facts: A historical précis of the early proofs (see also [1]; the statement of the CBHD Theorem as usually given in Algebra and that employed in the Analysis of linear PDE's; a review of proofs of the CBHD Theorem (as given by: Bourbaki; Hausdorff; Dynkin; Varadarajan together with a unifying demonstrational approach; an application to the Third Theorem of Lie (in local form. Some new results will be also commented: The intertwinement of the CBHD Theorem with the Theorem of Poincaré-Birkhoff-Witt and with the free Lie algebras (see [12]; recent results on optimal domains of convergence.

  8. Gordon Baker, Wittgensteinian Philosophical Conceptions and Perspicuous Representation: the Possibility of Multidimensional Logical Descriptions

    Directory of Open Access Journals (Sweden)

    Oskari Kuusela

    2014-12-01

    Full Text Available This paper discusses Gordon Baker’s interpretation of the later Wittgenstein, in particular his interpretation of the notion of Wittgensteinian philosophical conceptions (Auffassungen and the notions of non-exclusivity, local incompatibility, non-additivity and global pluralism which Baker uses to characterize Wittgensteinian conceptions. On the basis of this discussion, and a critique of certain features of Baker’s interpretation of Wittgensteinian conceptions, I introduce the notion of a multidimensional logical description of language use, explaining how this notion, which Baker’s interpretation excludes, constitutes and important element of the later Wittgenstein’s philosophical method of clarification and perspicuous representation. I conclude by explaining how Baker’s problematic notions of local incompatibility and non-additivity, if they are seen in the light of Wittgenstein’s criticisms of certain views of the completeness of philosophical or logical accounts, nevertheless point in the right direction.

  9. Painful swollen leg – think beyond deep vein thrombosis or Baker's cyst

    Directory of Open Access Journals (Sweden)

    Babu Vinayagam

    2008-01-01

    Full Text Available Abstract Background The diagnosis of deep vein thrombosis of leg is very common in clinical practice. Not infrequently a range of pathologies are diagnosed after excluding a thrombosis, often after a period of anticoagulation. Case presentation This is a report of three patients who presented with a painful swollen leg and were initially treated as a deep vein thrombosis or a baker's cyst, but later diagnosed as a pleomorphic sarcoma, a malignant giant cell tumor of the muscle and a myxoid liposarcoma. A brief review of such similar reports and the relevant literature is presented. Conclusion A painful swollen leg is a common clinical scenario and though rare, tumors must be thought of without any delay, in a duplex negative, low risk deep vein thrombosis situation.

  10. Qualitative and quantitative multiplexed proteomic analysis of complex yeast protein fractions that modulate the assembly of the yeast prion Sup35p.

    Directory of Open Access Journals (Sweden)

    Virginie Redeker

    Full Text Available BACKGROUND: The aggregation of the baker's yeast prion Sup35p is at the origin of the transmissible [PSI(+] trait. We and others have shown that molecular chaperones modulate Sup35p aggregation. However, other protein classes might be involved in [PSI(+] formation. RESULTS: We designed a functional proteomic study that combines two techniques to identify modulators of Sup35p aggregation and describe the changes associated to [PSI(+] formation. The first allows measuring the effect of fractionated Saccharomyces cerevisiae cytosolic extracts from [PSI(+] and [psi(-] yeast cells on Sup35p assembly. The second is a multiplex qualitative and quantitative comparison of protein composition of active and inactive fractions using a gel-free and label-free LC-MS approach. We identify changes in proteins involved in translation, folding, degradation, oxido-reduction and metabolic processes. CONCLUSION: Our functional proteomic study provides the first inventory list of over 300 proteins that directly or indirectly affect Sup35p aggregation and [PSI(+] formation. Our results highlight the complexity of the cellular changes accompanying [PSI(+] formation and pave the way for in vitro studies aimed to document the effect of individual and/or combinations of proteins identified here, susceptible of affecting Sup35p assembly.

  11. Uranium geology of the eastern Baker Lake basin, District of Keewatin, Northwest Territories

    International Nuclear Information System (INIS)

    Miller, A.R.

    1980-01-01

    Proterozoic sequences associated with major unconformities are potential uranium metallogenic provinces. Late Aphebian to Paleohelikian Dubawnt Group contintental clastic sedimentary and subaerial alkaline volcanic rocks and underlying Archean gneisses, District of Keewatin, Northwest Territories, represent one such uraniferous metallogenic province. Three types of uranium mineralization are present in the eastern Baker Lake basin, which extends from Christopher Island at the eastern end of Baker Lake southwestwards to the western limit of Thirty Mile Lake. The three uranium associations are: 1) fracture controlled mineralization in the Dubawnt Group and basement gneisses (U-Cu-Ag-Au-Se or U-Cu-Pb-Mo-Zn), 2)diatreme breccia mineralization in basement gneisses (U-Cu-Zn), and 3) impregnation and microfracture mineralization in altered arkose peripheral to lamprophyre dykes(U-Cu-Ag). Hydrothermal fracture related mineralization is controlled by northwest- and east-northeast-trending fault-fracture zones. Diatreme breccia mineralization results from the channelling of groundwaters through highly permeable brecciated gneiss. Mineralization within the altered Kazan arkose peripheral to alkaline dyke complexes formed by a two stage process. Iron and copper sulphides and silver were deposited within the outer portions of the thermal aureole in response to a temperature and Eh gradient across a convective cell created by the thermal anomaly of the dyke complex. The epigenetic sulphide mineralization subsequently provided the reducing environment for precipitation of uranium from groundwater. All three uranium associations show a close spatial distribution to the basal Dubawnt unconformity. The lithological and structural relationships of the Dubawnt Group rocks, types of mineralization and associated alteration assemblages are strikingly similar to the Beaverlodge district, Saskatchewan. (author)

  12. Yeast strains and methods of use thereof

    OpenAIRE

    Goddard, Matthew Robert; Gardner, Richard Clague; Anfang, Nicole

    2013-01-01

    The present invention relates to yeast strains and, in particular, to yeast stains for use in fermentation processes. The invention also relates to methods of fermentation using the yeast strains of the invention either alone or in combination with other yeast strains. The invention thither relates to methods for the selection of yeast strains suitable for fermentation cultures by screening for various metabolic products and the use of specific nutrient sources.

  13. 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...

  14. Structural investigations of yeast mannans

    International Nuclear Information System (INIS)

    Rademacher, K.H.

    1983-01-01

    Cell wall mannans were isolated from 8 different Candida species and separated in oligosaccharides by partial acetolysis. After gel chromatography specific acetolysis patterns were obtained. The 13 C NMR spectra of mannans and oligosaccharides were recorded. Signals at delta = 93.1 - 105.4 were assigned to certain chemical structures. Both the spectral patterns and the acetolysis patterns of the yeast mannans can be used for the discrimination of related yeasts. (author)

  15. Accumulation of linear mitochondrial DNA fragments in the nucleus shortens the chronological life span of yeast.

    Science.gov (United States)

    Cheng, Xin; Ivessa, Andreas S

    2012-10-01

    Translocation of mitochondrial DNA (mtDNA) fragments to the nucleus and insertion of those fragments into nuclear DNA has been observed in several organisms ranging from yeast to plants and mammals. Disruption of specific nuclear genes by de novo insertions of mtDNA fragments has even been linked to the initiation of several human diseases. Recently, we demonstrated that baker's yeast strains with high rates of mtDNA fragments migrating to the nucleus (yme1-1 mutant) exhibit short chronological life spans (CLS). The yeast CLS is determined by the survival of non-dividing cell populations. Here, we show that lack of the non-homologous-end-joining enzyme DNA ligase IV (DNL4) can rescue the short CLS of the yme1-1 mutant. In fission yeast, DNA ligase IV has been shown to be required for the capture of mtDNA fragments during the repair of double-stranded DNA breaks in nuclear DNA. In further analyses using pulse field gel and 2D gel electrophoresis we demonstrate that linear mtDNA fragments with likely nuclear localization accumulate in the yme1-1 mutant. The accumulation of the linear mtDNA fragments in the yme1-1 mutant is suppressed when Dnl4 is absent. We propose that the linear nuclear mtDNA fragments accelerate the aging process in the yme1-1 mutant cells by possibly affecting nuclear processes including DNA replication, recombination, and repair as well as transcription of nuclear genes. We speculate further that Dnl4 protein has besides its function as a ligase also a role in DNA protection. Dnl4 protein may stabilize the linear mtDNA fragments in the nucleus by binding to their physical ends. In the absence of Dnl4 protein the linear fragments are therefore unprotected and possibly degraded by nuclear nucleases. Copyright © 2012 Elsevier GmbH. All rights reserved.

  16. Continuous measurement of ethanol production by aerobic yeast suspensions with an enzyme electrode

    Energy Technology Data Exchange (ETDEWEB)

    Verduyn, C.; Zomerdijk, T.P.L.; Dijken, J.P. van; Scheffers, W.A.

    1984-03-01

    An alcohol electrode was constructed which consisted of an oxygen probe onto which alcohol oxidase was immobilized. This enzyme electrode was used, in combination with a reference oxygen electrode, to study the short-term kinetics of alcoholic fermentation by aerobic yeast suspensions after pulsing with glucose. The results demonstrate that this device is an excellent tool in obtaining quantitative data on the short-term expression of the Crabtree effect in yeasts. Samples from aerobic glucose-limited chemostat cultures of Saccharomyces cerevisiae not producing ethanol, immediately (within 2 min) exhibited aerobic alcohol fermentation after being pulsed with excess glucose. With chemostat-grown Candida utilis, however, ethanol production was not detactable even at high sugar concentrations. The Crabtree effect in S. cerevisiae was studied in more detail with commercial baker's yeast. Ethanol formation occurred only at initial glucose concentrations exceeding 150 mgx1/sup -1/, and the rate of alcoholic fermentation increased with increasing glucose concentrations up to 1,000 mgx1/sup -1/ glucose. Similar experiments with batch cultures of certain ''non-fermentative'' yeasts revealed that these organisms are capable of alcoholic fermentation. Thus, even under fully aerobic conditions, Hansenula nonfermentans and Candida buffonii produced ethanol after being pulsed with glucose. In C. buffonii ethanol formation was already apparent at very low glucose concentrations (10 mgx1/sup -1/) and alcoholic fermentation even proceeded at a higher rate than in S. cerevisiae. With Rhodotorula rubra, however, the rate of ethanol formation was below the detection limit, i.e., less than 0.1 mmolxg cells/sup -1/xh/sup -1/.

  17. Biotechnological production of high specific activity L-35S-cysteine and L-35S-methionine by using a diploid yeast Saccharomyces cerevisiae

    International Nuclear Information System (INIS)

    Gajendiran, N.; Jayachandran, N.; Unny, V.K.P.; Thyagarajan, S.; Rao, B.S.

    1994-01-01

    High specific activity L- 3 5 S-cysteine and L- 35 S-methionine were synthesised by using a wild type diploid strain of baker's yeast-Saccharomyces cerevisiae. Yeast cells were grown in a sulphur depleted synthetic medium in which Na 2 3 5 SO 4 (50 mCi/ml) was supplemented as the sole sulphur source. The level of incorporation was 60% on an average. The protein hydrolysate of the cultured cells was subjected to paper and column chromatographic separations to get the individual L- 3 5 S-aminoacids. The radiochemical yields of cysteine and methionine were 6-7% and 18-20% respectively. The radiochemical purity of the products was >95%. The highest specific activity for the products obtained by employing this method was 1100 Ci/mmole from the starting material, Na 2 35 SO 4 , with a specific activity of 1350 Ci/mmole. (Author)

  18. Oral yeast colonization throughout pregnancy.

    Science.gov (United States)

    Rio, R; Simões-Silva, L; Garro, S; Silva, M-J; Azevedo, Á; Sampaio-Maia, B

    2017-03-01

    Recent studies suggest that placenta may harbour a unique microbiome that may have origin in maternal oral microbiome. Although the major physiological and hormonal adjustments observed in pregnant women lead to biochemical and microbiological modifications of the oral environment, very few studies evaluated the changes suffered by the oral microbiota throughout pregnancy. So, the aim of our study was to evaluate oral yeast colonization throughout pregnancy and to compare it with non-pregnant women. The oral yeast colonization was assessed in saliva of 30 pregnant and non-pregnant women longitudinally over a 6-months period. Demographic information was collected, a non-invasive intra-oral examination was performed and saliva flow and pH were determined. Pregnant and non-pregnant groups were similar regarding age and level of education. Saliva flow rate did not differ, but saliva pH was lower in pregnant than in non-pregnant women. Oral yeast prevalence was higher in pregnant than in non-pregnant women, either in the first or in the third trimester, but did not attain statistical significance. In individuals colonized with yeast, the total yeast quantification (Log10CFU/mL) increase from the 1st to the 3rd trimester in pregnant women, but not in non-pregnant women. Pregnancy may favour oral yeast growth that may be associated with an acidic oral environment.

  19. 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.

  20. Yeast ribosomal proteins

    International Nuclear Information System (INIS)

    Otaka, E.; Kobata, K.

    1978-01-01

    The cytoplasmic 80s ribosomal proteins from the cells of yeast Saccharomyces cerevisiae were analyzed by SDS two-dimensional polyacrylamide gel electrophoresis. Seventyfour proteins were identified and consecutively numbered from 1 to 74. Upon oxidation of the 80s proteins with performic acid, ten proteins (no. 15, 20, 35, 40, 44, 46, 49, 51, 54 and 55) were dislocated on the gel without change of the total number of protein spots. Five proteins (no. 8, 14, 16, 36 and 74) were phosphorylated in vivo as seen in 32 P-labelling experiments. The large and small subunits separated in low magnesium medium were analyzed by the above gel electrophoresis. At least forty-five and twenty-eight proteins were assumed to be in the large and small subunits, respectively. All proteins found in the 80s ribosomes, except for no. 3, were detected in either subunit without appearance of new spots. The acidic protein no. 3 seems to be lost during subunit dissociation. (orig.) [de

  1. Metabolic regulation of yeast

    Science.gov (United States)

    Fiechter, A.

    1982-12-01

    Metabolic regulation which is based on endogeneous and exogeneous process variables which may act constantly or time dependently on the living cell is discussed. The observed phenomena of the regulation are the result of physical, chemical, and biological parameters. These parameters are identified. Ethanol is accumulated as an intermediate product and the synthesis of biomass is reduced. This regulatory effect of glucose is used for the aerobic production of ethanol. Very high production rates are thereby obtained. Understanding of the regulation mechanism of the glucose effect has improved. In addition to catabolite repression, several other mechanisms of enzyme regulation have been described, that are mostly governed by exogeneous factors. Glucose also affects the control of respiration in a third class of yeasts which are unable to make use of ethanol as a substrate for growth. This is due to the lack of any anaplerotic activity. As a consequence, diauxic growth behavior is reduced to a one-stage growth with a drastically reduced cell yield. The pulse chemostat technique, a systematic approach for medium design is developed and medium supplements that are essential for metabolic control are identified.

  2. Yeast Flocculation—Sedimentation and Flotation

    Directory of Open Access Journals (Sweden)

    Graham G. Stewart

    2018-04-01

    Full Text Available Unlike most fermentation alcohol beverage production processes, brewers recycle their yeast. This is achieved by employing a yeast culture’s: flocculation, adhesion, sedimentation, flotation, and cropping characteristics. As a consequence of yeast recycling, the quality of the cropped yeast culture’s characteristics is critical. However, the other major function of brewer’s yeast is to metabolise wort into ethanol, carbon dioxide, glycerol, and other fermentation products, many of which contribute to beer’s overall flavour characteristics. This review will only focus on brewer’s yeast flocculation characteristics.

  3. Understanding the Effects of Genotype, Growing Year, and Breeding on Tunisian Durum Wheat Allergenicity. 1. The Baker's Asthma Case.

    Science.gov (United States)

    Boukid, Fatma; Prandi, Barbara; Sforza, Stefano; Sayar, Rhouma; Seo, Yong Weon; Mejri, Mondher; Yacoubi, Ines

    2017-07-19

    Baker's asthma is a serious airway disease triggered by wheat protein CM3 α-amylase/trypsin inhibitor. The purpose of the present study was to investigate the impact of genotype and crop year on allergen CM3 α-amylase/trypsin inhibitor associated with baker's asthma. A historical series of Tunisian durum wheat (100 accessions), derived from three crop years, was used to compare the amount of CM3 from landraces to advanced cultivars. CM3 protein quantification was assessed after an enzymatic cleavage of the soluble protein extracts on a UPLC/ESI-MS system, using a marker peptide for its quantification. Combined data analysis of variance revealed an important effect of genotype, crop year, and their interaction. The CM3 allergenic proteins were found to significantly vary among studied genotypes, as confirmed by genetic variability, coefficient of variance, heritability, and genetic advance.

  4. Effects of alkylresorcinols on volume and structure of yeast-leavened bread.

    Science.gov (United States)

    Andersson, Annica Am; Landberg, Rikard; Söderman, Thomas; Hedkvist, Sofie; Katina, Kati; Juvonen, Riikka; Holopainen, Ulla; Lehtinen, Pekka; Aman, Per

    2011-01-30

    Alkylresorcinols (AR) are amphiphilic phenolic compounds found in high amounts in wheat, durum wheat and rye, with different homologue composition for each cereal. The effect of different amounts of added AR from these cereals on bread volume, height, porosity and microstructure was studied. Breads with added rye bran (with high levels of AR) or acetone-extracted rye bran (with low levels of AR) were also baked, as well as breads with finely milled forms of each of these brans. Breads with high amounts of added AR, irrespective of AR homologue composition, had a lower volume, a more compact structure and an adverse microstructure compared with breads with no or low levels of added AR. AR were also shown to inhibit the activity of baker's yeast. There was no difference in bread volume and porosity between bread baked with rye bran and acetone-extracted rye bran or with brans of different particle size. Irrespective of homologue composition, AR had a negative effect on wheat bread properties when added in high amounts as purified extracts from wheat, durum wheat and rye. Natural levels of AR in rye bran, however, did not affect the volume and porosity of yeast-leavened wheat breads. 2010 Society of Chemical Industry.

  5. Genomic reconstruction to improve bioethanol and ergosterol production of industrial yeast Saccharomyces cerevisiae.

    Science.gov (United States)

    Zhang, Ke; Tong, Mengmeng; Gao, Kehui; Di, Yanan; Wang, Pinmei; Zhang, Chunfang; Wu, Xuechang; Zheng, Daoqiong

    2015-02-01

    Baker's yeast (Saccharomyces cerevisiae) is the common yeast used in the fields of bread making, brewing, and bioethanol production. Growth rate, stress tolerance, ethanol titer, and byproducts yields are some of the most important agronomic traits of S. cerevisiae for industrial applications. Here, we developed a novel method of constructing S. cerevisiae strains for co-producing bioethanol and ergosterol. The genome of an industrial S. cerevisiae strain, ZTW1, was first reconstructed through treatment with an antimitotic drug followed by sporulation and hybridization. A total of 140 mutants were selected for ethanol fermentation testing, and a significant positive correlation between ergosterol content and ethanol production was observed. The highest performing mutant, ZG27, produced 7.9 % more ethanol and 43.2 % more ergosterol than ZTW1 at the end of fermentation. Chromosomal karyotyping and proteome analysis of ZG27 and ZTW1 suggested that this breeding strategy caused large-scale genome structural variations and global gene expression diversities in the mutants. Genetic manipulation further demonstrated that the altered expression activity of some genes (such as ERG1, ERG9, and ERG11) involved in ergosterol synthesis partly explained the trait improvement in ZG27.

  6. Application of synthetic biology for production of chemicals in yeast Saccharomyces cerevisiae.

    Science.gov (United States)

    Li, Mingji; Borodina, Irina

    2015-02-01

    Synthetic biology and metabolic engineering enable generation of novel cell factories that efficiently convert renewable feedstocks into biofuels, bulk, and fine chemicals, thus creating the basis for biosustainable economy independent on fossil resources. While over a hundred proof-of-concept chemicals have been made in yeast, only a very small fraction of those has reached commercial-scale production so far. The limiting factor is the high research cost associated with the development of a robust cell factory that can produce the desired chemical at high titer, rate, and yield. Synthetic biology has the potential to bring down this cost by improving our ability to predictably engineer biological systems. This review highlights synthetic biology applications for design, assembly, and optimization of non-native biochemical pathways in baker's yeast Saccharomyces cerevisiae We describe computational tools for the prediction of biochemical pathways, molecular biology methods for assembly of DNA parts into pathways, and for introducing the pathways into the host, and finally approaches for optimizing performance of the introduced pathways. © FEMS 2015. All rights reserved. For permissions, please e-mail: journals.permission@oup.com.

  7. Understanding bistability in yeast glycolysis using general properties of metabolic pathways.

    Science.gov (United States)

    Planqué, Robert; Bruggeman, Frank J; Teusink, Bas; Hulshof, Josephus

    2014-09-01

    Glycolysis is the central pathway in energy metabolism in the majority of organisms. In a recent paper, van Heerden et al. showed experimentally and computationally that glycolysis can exist in two states, a global steady state and a so-called imbalanced state. In the imbalanced state, intermediary metabolites accumulate at low levels of ATP and inorganic phosphate. It was shown that Baker's yeast uses a peculiar regulatory mechanism--via trehalose metabolism--to ensure that most yeast cells reach the steady state and not the imbalanced state. Here we explore the apparent bistable behaviour in a core model of glycolysis that is based on a well-established detailed model, and study in great detail the bifurcation behaviour of solutions, without using any numerical information on parameter values. We uncover a rich suite of solutions, including so-called imbalanced states, bistability, and oscillatory behaviour. The techniques employed are generic, directly suitable for a wide class of biochemical pathways, and could lead to better analytical treatments of more detailed models. Copyright © 2014 Elsevier Inc. All rights reserved.

  8. Prevalence of IgE against neuromuscular blocking agents in hairdressers and bakers.

    Science.gov (United States)

    Dong, S; Acouetey, D S; Guéant-Rodriguez, R-M; Zmirou-Navier, D; Rémen, T; Blanca, M; Mertes, P M; Guéant, J-L

    2013-11-01

    Allergic IgE-mediated reactions to neuromuscular blocking agents (NMBAs) are the main cause of immediate hypersensitivity reactions in anaesthesia; their predominant occurrence in the absence of previous exposure to NMBAs suggests a risk related to environmental exposure. To investigate the prevalence of specific IgE to quaternary ammonium ions in two populations professionally exposed to quaternary ammonium compounds, in the north-eastern France. The study had a retrospective follow-up design whereby apprentices were assessed after their 2-year training period as apprentices. The professionally exposed hairdresser populations (n = 128) were compared with baker/pastry makers (n = 108) and 'non-exposed' matched control subjects (n = 379). We observed a 4.6-fold higher frequency of positive IgE against quaternary ammonium ions in hairdressers (HD), compared with baker/pastry makers (BP) and control (C) groups. The competitive inhibition of quaternary ammonium Sepharose radioimmunoassay (QAS-IgE RIA) with succinylcholine was significantly higher in HD, compared with BP and C groups, with inhibition percentage of 66.2 ± 7.4, 39.7 ± 6.0 and 43.8 ± 9.9, respectively (P  100 kU/L were the two significant predictors of IgE-sensitization against quaternary ammonium ions in the multivariate analysis of a model that included age, sex, professional exposure, increased concentration of total IgE (IgE > 100 kU/L) and positive IgE against prevalent allergens (Phadiatop(®) ; P = 0.019 and P = 0.001, respectively). The exposure to hairdressing professional occupational factors increases IgE-sensitization to NMBAs and quaternary ammonium ion compounds used in hairdressing. Besides the pholcodine hypothesis, our study suggests that repetitive exposure to quaternary ammonium compounds used in hairdressing is a risk factor for NMBAs sensitization. © 2013 John Wiley & Sons Ltd.

  9. Geochemical results of a hydrothermally altered area at Baker Creek, Blaine County, Idaho

    Science.gov (United States)

    Erdman, James A.; Moye, Falma J.; Theobald, Paul K.; McCafferty, Anne E.; Larsen, Richard K.

    2001-01-01

    The area immediately east of Baker Creek, Blaine County, Idaho, is underlain by a thick section of mafic to intermediate lava flows of the Eocene Challis Volcanic Group. Widespread propylitic alteration surrounds a zone of argillic alteration and an inner core of phyllic alteration. Silicified breccia is present along an east-trending fault within the zone of phyllic alteration. As part of a reconnaissance geochemical survey, soils and plants were sampled. Several species of plants (Douglas-fir [ Pseudotsuga menziesii ], mountain big sagebrush [ Artemisia tridentata ssp. vaseyana ], and elk sedge [ Carex geyerii ]) were collected from 10 upland localities and stream sediments, panned concentrates, and aquatic mosses were collected from 16 drainage basin localities all of which were generally within the area of alteration. Geochemical results yielded anomalous concentrations of molybenum, zinc, silver, and lead in at least half of the seven different sample media and of gold, thallium, arsenic, antimony, manganese, boron, cadmium, bismuth, copper, and beryllium in from one to four of the various media. Part of this suite of elements? silver, gold, arsenic, antimony, thallium, and manganese? suggests that the mineralization in the area is epithermal. Barite and pyrite (commonly botryoidal-framboidal) are widespread throughout the area sampled. Visible gold and pyromorphite (a secondary lead mineral) were identified in only one small drainage basin, but high levels of gold were detected in aquatic mosses over a larger area. Data from the upland and stream sampling indicate two possible mineralized areas. The first mineralized area was identified by a grab sample from an outcrop of quartz stockwork that contained 50 ppb Au, 1.5 ppm Ag, and 50 ppm Mo. Although the soil and plant species that were sampled in the area indicated mineralized bedrock, the Douglas-fir samples were the best indicators of the silver anomaly. The second possible mineralized area centers on the

  10. Simplifying the Reinsch algorithm for the Baker-Campbell-Hausdorff series

    Science.gov (United States)

    Van-Brunt, Alexander; Visser, Matt

    2016-02-01

    The Goldberg version of the Baker-Campbell-Hausdorff series computes the quantity Z ( X , Y ) = ln (" separators=" e X e Y ) = ∑ w g ( w ) w ( X , Y ) , where X and Y are not necessarily commuting in terms of "words" constructed from the {X, Y} "alphabet." The so-called Goldberg coefficients g(w) are the central topic of this article. This Baker-Campbell-Hausdorff series is a general purpose tool of very wide applicability in mathematical physics, quantum physics, and many other fields. The Reinsch algorithm for the truncated series permits one to calculate the Goldberg coefficients up to some fixed word length |w| by using nilpotent (|w| + 1) × (|w| + 1) matrices. We shall show how to further simplify the Reinsch algorithm, making its implementation (in principle) utterly straightforward using "off the shelf" symbolic manipulation software. Specific computations provide examples which help to provide a deeper understanding of the Goldberg coefficients and their properties. For instance, we shall establish some strict bounds (and some equalities) on the number of non-zero Goldberg coefficients. Unfortunately, we shall see that the number of nonzero Goldberg coefficients often grows very rapidly (in fact exponentially) with the word length |w|. Furthermore, the simplified Reinsch algorithm readily generalizes to many closely related but still quite distinct problems—we shall also present closely related results for the symmetric product S ( X , Y ) = ln (" separators=" e X / 2 e Y e X / 2 ) = ∑ w g S ( w ) w ( X , Y ) . Variations on such themes are straightforward. For instance, one can just as easily consider the "loop" product L ( X , Y ) = ln (" separators=" e X e Y e - X e - Y ) = ∑ w g L ( w ) w ( X , Y ) . This "loop" type of series is of interest, for instance, when considering either differential geometric parallel transport around a closed curve, non-Abelian versions of Stokes' theorem, or even Wigner rotation/Thomas precession in special

  11. Consumption of agro-industrial supplies by the baker subsector of Palmira, Valle, Colombia. Consumo de insumos agroindustriales por el subsector panificador de Palmira, Valle del Cauca.

    Directory of Open Access Journals (Sweden)

    Adarme J Wilson

    2007-06-01

    Full Text Available The indicators of agroindustrial consumption in the bakers subsector Pymes play a primary role for designing sustainable strategies for the small craftsman of bread. The administrative, operative and human talent subsystems were evaluated, in 30 of 178 organizations that conformed the bakers subsystems of Palmira on 2005. The estimated annual consumption of wheat flour on 2004 was 2016 t; 348 t of sugar; 240 t of cheese; 54 t of salt; 492 t of margarine; 99 t of yeast; 151200 panels of eggs. With regarding to raw materials it consumes 384000 m3 of natural gas; 1.2 million kw of electric power and 156000 m3 of water. The sector generates 681 direct employments. Map is presented with the location of 86% of the bakeries registered in the Trade Chamber. There is not a unique bakery that had implemented a program of Good Manufacture Practices BPM in an integral way, that meets the National Institute of Medications and Foods Surveillance INVIMA Standars, that has of a system of Hazard Analysis and Critical Control Point (HACCP or have been is to be certified with Quality Assuring Standars (ISO 9000, and/or Environmental Administration (ISO 14000, with occupational health programs (OHSAS 18000 and permanent improvement programs relative to administrative and commercial aspects.Los indicadores de consumo agroindustrial en las Pymes del subsector panificador resultan apremiantes para el diseño de estrategias de sostenibilidad para los pequeños artesanos del pan. Se evaluaron los subsistemas administrativos, talento humano y operativo en 30 de las 178 organizaciones que conformaron el subsistema panificador de Palmira en el 2005. El consumo estimado anual para el 2004 de harina de trigo fue 2.016 t; 348 t de azúcar; 240 t de queso; 54 t de sal; 492 t de margarina; 99 t de levadura; 151.200 paneles de huevos. En materias primas auxiliares consume 384.000 m3 de gas natural; 1.2 millones de kw de energía eléctrica y 156.000 m3 de agua. El sector genera

  12. Physical Forces Modulate Oxidative Status and Stress Defense Meditated Metabolic Adaptation of Yeast Colonies: Spaceflight and Microgravity Simulations

    Science.gov (United States)

    Hammond, Timothy G.; Allen, Patricia L.; Gunter, Margaret A.; Chiang, Jennifer; Giaever, Guri; Nislow, Corey; Birdsall, Holly H.

    2018-05-01

    Baker's yeast ( Saccharomyces cerevisiae) has broad genetic homology to human cells. Although typically grown as 1-2mm diameter colonies under certain conditions yeast can form very large (10 + mm in diameter) or `giant' colonies on agar. Giant yeast colonies have been used to study diverse biomedical processes such as cell survival, aging, and the response to cancer pharmacogenomics. Such colonies evolve dynamically into complex stratified structures that respond differentially to environmental cues. Ammonia production, gravity driven ammonia convection, and shear defense responses are key differentiation signals for cell death and reactive oxygen system pathways in these colonies. The response to these signals can be modulated by experimental interventions such as agar composition, gene deletion and application of pharmaceuticals. In this study we used physical factors including colony rotation and microgravity to modify ammonia convection and shear stress as environmental cues and observed differences in the responses of both ammonia dependent and stress response dependent pathways We found that the effects of random positioning are distinct from rotation. Furthermore, both true and simulated microgravity exacerbated both cellular redox responses and apoptosis. These changes were largely shear-response dependent but each model had a unique response signature as measured by shear stress genes and the promoter set which regulates them These physical techniques permitted a graded manipulation of both convection and ammonia signaling and are primed to substantially contribute to our understanding of the mechanisms of drug action, cell aging, and colony differentiation.

  13. Physical Forces Modulate Oxidative Status and Stress Defense Meditated Metabolic Adaptation of Yeast Colonies: Spaceflight and Microgravity Simulations

    Science.gov (United States)

    Hammond, Timothy G.; Allen, Patricia L.; Gunter, Margaret A.; Chiang, Jennifer; Giaever, Guri; Nislow, Corey; Birdsall, Holly H.

    2017-12-01

    Baker's yeast (Saccharomyces cerevisiae) has broad genetic homology to human cells. Although typically grown as 1-2mm diameter colonies under certain conditions yeast can form very large (10 + mm in diameter) or `giant' colonies on agar. Giant yeast colonies have been used to study diverse biomedical processes such as cell survival, aging, and the response to cancer pharmacogenomics. Such colonies evolve dynamically into complex stratified structures that respond differentially to environmental cues. Ammonia production, gravity driven ammonia convection, and shear defense responses are key differentiation signals for cell death and reactive oxygen system pathways in these colonies. The response to these signals can be modulated by experimental interventions such as agar composition, gene deletion and application of pharmaceuticals. In this study we used physical factors including colony rotation and microgravity to modify ammonia convection and shear stress as environmental cues and observed differences in the responses of both ammonia dependent and stress response dependent pathways We found that the effects of random positioning are distinct from rotation. Furthermore, both true and simulated microgravity exacerbated both cellular redox responses and apoptosis. These changes were largely shear-response dependent but each model had a unique response signature as measured by shear stress genes and the promoter set which regulates them These physical techniques permitted a graded manipulation of both convection and ammonia signaling and are primed to substantially contribute to our understanding of the mechanisms of drug action, cell aging, and colony differentiation.

  14. The yeast replicative aging model.

    Science.gov (United States)

    He, Chong; Zhou, Chuankai; Kennedy, Brian K

    2018-03-08

    It has been nearly three decades since the budding yeast Saccharomyces cerevisiae became a significant model organism for aging research and it has emerged as both simple and powerful. The replicative aging assay, which interrogates the number of times a "mother" cell can divide and produce "daughters", has been a stalwart in these studies, and genetic approaches have led to the identification of hundreds of genes impacting lifespan. More recently, cell biological and biochemical approaches have been developed to determine how cellular processes become altered with age. Together, the tools are in place to develop a holistic view of aging in this single-celled organism. Here, we summarize the current state of understanding of yeast replicative aging with a focus on the recent studies that shed new light on how aging pathways interact to modulate lifespan in yeast. Copyright © 2018. Published by Elsevier B.V.

  15. [Yeast species in vulvovaginitis candidosa].

    Science.gov (United States)

    Nemes-Nikodém, Éva; Tamási, Béla; Mihalik, Noémi; Ostorházi, Eszter

    2015-01-04

    Vulvovaginal candidiasis is the most common mycosis, however, the available information about antifungal susceptibilities of these yeasts is limited. To compare the gold standard fungal culture with a new molecular identification method and report the incidence of yeast species in vulvovaginitis candidosa. The authors studied 370 yeasts isolated from vulvovaginal candidiasis and identified them by phenotypic and molecular methods. The most common species was Candida albicans (85%), followed by Candida glabrata, and other Candida species. At present there are no recommendations for the evaluation of antifungal susceptibility of pathogenic fungal species occurring in vulvovaginal candidiasis and the natural antifungal resistance of the different species is known only. Matrix Assisted Laser Desorption Ionization Time of Flight identification can be used to differentiate the fluconazole resistant Candida dubliniensis and the sensitive Candida albicans strains.

  16. Chemical constituents of the essential oil, antioxidant and antibacterial activities from Elettariopsis curtisii Baker.

    Directory of Open Access Journals (Sweden)

    Vanida Chairgulprasert

    2008-08-01

    Full Text Available Elettariopsis curtisii Baker, the culinary and medicinal herb, was investigated to elucidate its chemical constituents and determine antioxidant and antibacterial activities. The essential oil of E. curtisii was obtained by steam distillation of fresh rhizomes in a maximum yield of 0.63%. GC-MS data indicated the presence of six compounds, of which trans-2-decenal (78.03% was the principal constituent. The essential oils and also the hexane, dichloromethane and methanol extracts from the rhizomes and leaves were assessed for antioxidant and antibacterial activities. In an evaluation of antioxidant activity, the crude dichloromethane extract of the leaves exhibited the highest scavenging effect on the DPPH radicalwith an EC50 of 0.28+0.01 mg/mL. The leaf dichloromethane extract also had the highest total phenol concentration, (73.4+2.80 mg GA/g of extract whereas the crude methanol extract from the rhizomes had the highest reducing power with an EC50 of 2.07+0.06 mg/mL. In terms of antibacterial activity, the essential oil (distilled from either the leaves or the rhizomesdisplayed the highest inhibitory activity, with the same MID value of 1 mg/disc against 5 strains of bacteria, Bacillus subtilis,Escherichia coli, Staphylococcus aureus, Sarcina sp. and Pseudomonas aeruginosa.

  17. 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...

  18. 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

  19. 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

  20. Inaccurate DNA synthesis in cell extracts of yeast producing active human DNA polymerase iota.

    Science.gov (United States)

    Makarova, Alena V; Grabow, Corinn; Gening, Leonid V; Tarantul, Vyacheslav Z; Tahirov, Tahir H; Bessho, Tadayoshi; Pavlov, Youri I

    2011-01-31

    Mammalian Pol ι has an unusual combination of properties: it is stimulated by Mn(2+) ions, can bypass some DNA lesions and misincorporates "G" opposite template "T" more frequently than incorporates the correct "A." We recently proposed a method of detection of Pol ι activity in animal cell extracts, based on primer extension opposite the template T with a high concentration of only two nucleotides, dGTP and dATP (incorporation of "G" versus "A" method of Gening, abbreviated as "misGvA"). We provide unambiguous proof of the "misGvA" approach concept and extend the applicability of the method for the studies of variants of Pol ι in the yeast model system with different cation cofactors. We produced human Pol ι in baker's yeast, which do not have a POLI ortholog. The "misGvA" activity is absent in cell extracts containing an empty vector, or producing catalytically dead Pol ι, or Pol ι lacking exon 2, but is robust in the strain producing wild-type Pol ι or its catalytic core, or protein with the active center L62I mutant. The signature pattern of primer extension products resulting from inaccurate DNA synthesis by extracts of cells producing either Pol ι or human Pol η is different. The DNA sequence of the template is critical for the detection of the infidelity of DNA synthesis attributed to DNA Pol ι. The primer/template and composition of the exogenous DNA precursor pool can be adapted to monitor replication fidelity in cell extracts expressing various error-prone Pols or mutator variants of accurate Pols. Finally, we demonstrate that the mutation rates in yeast strains producing human DNA Pols ι and η are not elevated over the control strain, despite highly inaccurate DNA synthesis by their extracts.

  1. Inaccurate DNA synthesis in cell extracts of yeast producing active human DNA polymerase iota.

    Directory of Open Access Journals (Sweden)

    Alena V Makarova

    2011-01-01

    Full Text Available Mammalian Pol ι has an unusual combination of properties: it is stimulated by Mn(2+ ions, can bypass some DNA lesions and misincorporates "G" opposite template "T" more frequently than incorporates the correct "A." We recently proposed a method of detection of Pol ι activity in animal cell extracts, based on primer extension opposite the template T with a high concentration of only two nucleotides, dGTP and dATP (incorporation of "G" versus "A" method of Gening, abbreviated as "misGvA". We provide unambiguous proof of the "misGvA" approach concept and extend the applicability of the method for the studies of variants of Pol ι in the yeast model system with different cation cofactors. We produced human Pol ι in baker's yeast, which do not have a POLI ortholog. The "misGvA" activity is absent in cell extracts containing an empty vector, or producing catalytically dead Pol ι, or Pol ι lacking exon 2, but is robust in the strain producing wild-type Pol ι or its catalytic core, or protein with the active center L62I mutant. The signature pattern of primer extension products resulting from inaccurate DNA synthesis by extracts of cells producing either Pol ι or human Pol η is different. The DNA sequence of the template is critical for the detection of the infidelity of DNA synthesis attributed to DNA Pol ι. The primer/template and composition of the exogenous DNA precursor pool can be adapted to monitor replication fidelity in cell extracts expressing various error-prone Pols or mutator variants of accurate Pols. Finally, we demonstrate that the mutation rates in yeast strains producing human DNA Pols ι and η are not elevated over the control strain, despite highly inaccurate DNA synthesis by their extracts.

  2. Biosynthesis of acid phosphatase of baker's yeast . Characterization of a protoplast-bound fraction containing precursors of the exo-enzyme

    NARCIS (Netherlands)

    Boer, Pieter; Rijn, Herman J.M. van; Reinking, A.; Steyn-Parvé, Elizabeth P.

    1975-01-01

    1. 1.|Yest protoplasts, secreting acid phosphatase (orthophosphoric-monoester phosphohydrolase (acid optimum) EC 3.1.3.2) contain a small amount of firmly bound enzyme, even after lysis (Van Rijn, H.J.M.; Boer, P. and Steyn-Parvé, E.P. (1972) Biochim. Biophys. Acta 268, 431–441). The major part

  3. Osmotolerance and leavening ability in sweet and frozen sweet dough. Comparative analysis between Torulaspora delbrueckii and Saccharomyces cerevisiae baker's yeast strains.

    Science.gov (United States)

    Hernandez-Lopez, M J; Prieto, J A; Randez-Gil, F

    2003-01-01

    The response of Saccharomyces cerevisiae and freeze-tolerant Torulaspora delbrueckii strains to osmotic stress and their CO2 production capacity in sweet and frozen-sweet dough has been examined. T. delbrueckii strains, IGC5321 and IGC5323 showed higher leavening ability than Saccharomyces, specially after exposure to hyperosmotic stress of bread dough containing 20% sucrose and 2% salt added. In addition, Torulaspora and especially T. delbrueckii IGC5321 exhibited no loss of CO2 production capacity during freeze-thaw stress. Overall, these results appeared to indicate that Torulaspora cells are more tolerant than Saccharomyces to osmotic stress of bread dough. This trait correlated with a low invertase activity, a slow rate of trehalose mobilisation and the ability to respond rapidly to osmotic stress. Growth behaviour on high osmotic synthetic media was also examined. Cells of the IGC5321 strain showed intrinsic osmotolerance and ion toxicity resistance. However, T. delbrueckii IGC5323 exhibited a clear phenotype of osmosensitivity. Hence, this characteristic may not be essential or the only determinant for leavening ability in salted high-sugar dough.

  4. Diet, occupational exposure and early asthma incidence among bakers, pastry makers and hairdressers

    Directory of Open Access Journals (Sweden)

    Rémen Thomas

    2012-05-01

    Full Text Available Abstract Background The natural history of occupational asthma (OA is influenced by many determinants. This study aims to assess the combined roles of personal characteristics, including occupational exposure and nutritional habits, on the incidence of OA during the first years at work. Methods A nested case–control study was conducted within a retrospective cohort of young workers in the bakery, pastry-making and hairdressing sectors. Cases were subjects diagnosed as ‘confirmed’ or ‘probable’ OA consecutively to a medical visit (N = 31. Controls were subjects without OA (N = 196. Atopy was defined after blood specific IgE analysis, based on the PhadiatopTM test. Occupational exposure was characterized by standardized questionnaires and diet patterns by a food frequency questionnaire. Results Among bakers and pastry-makers, only atopy is an independent risk factor of OA (OR = 10.07 95%CI [2.76 – 36.65]. Among hairdressers, several variables are associated with OA. Body mass index (unit OR = 1.24 [1.03 – 1.48] and the score of exposure intensity (unit OR = 1.79 [1.05 – 3.05] are independent predictors of OA, but the role of atopy is weak (OR = 4.94 [0.66 – 36.75]. Intake of vitamin A is higher among hairdressers cases (crude p = 0.002, adjusted p = 0.01 after control for body mass index and atopy; the same observation is made for vitamin D (crude p = 0.004, adjusted p = 0.01. Conclusion This study suggests that the influence of several factors on the incidence of OA, including dietary vitamins, might vary across exposure settings.

  5. Diet, occupational exposure and early asthma incidence among bakers, pastry makers and hairdressers.

    Science.gov (United States)

    Rémen, Thomas; Acouetey, Dovi-Stéphanie; Paris, Christophe; Zmirou-Navier, Denis

    2012-05-29

    The natural history of occupational asthma (OA) is influenced by many determinants. This study aims to assess the combined roles of personal characteristics, including occupational exposure and nutritional habits, on the incidence of OA during the first years at work. A nested case-control study was conducted within a retrospective cohort of young workers in the bakery, pastry-making and hairdressing sectors. Cases were subjects diagnosed as 'confirmed' or 'probable' OA consecutively to a medical visit (N = 31). Controls were subjects without OA (N = 196). Atopy was defined after blood specific IgE analysis, based on the PhadiatopTM test. Occupational exposure was characterized by standardized questionnaires and diet patterns by a food frequency questionnaire. Among bakers and pastry-makers, only atopy is an independent risk factor of OA (OR = 10.07 95%CI [2.76 - 36.65]). Among hairdressers, several variables are associated with OA. Body mass index (unit OR = 1.24 [1.03 - 1.48]) and the score of exposure intensity (unit OR = 1.79 [1.05 - 3.05]) are independent predictors of OA, but the role of atopy is weak (OR = 4.94 [0.66 - 36.75]). Intake of vitamin A is higher among hairdressers cases (crude p = 0.002, adjusted p = 0.01 after control for body mass index and atopy); the same observation is made for vitamin D (crude p = 0.004, adjusted p = 0.01). This study suggests that the influence of several factors on the incidence of OA, including dietary vitamins, might vary across exposure settings.

  6. Climate change impacts on the Lehman-Baker Creek drainage in the Great Basin National Park

    Science.gov (United States)

    Volk, J. M.

    2013-12-01

    Global climate models (GCMs) forced by increased CO2 emissions forecast anomalously dry and warm trends over the southwestern U.S. for the 21st century. The effect of warmer conditions may result in decreased surface water resources within the Great Basin physiographic region critical for ecology, irrigation and municipal water supply. Here we use downscaled GCM output from the A2 and B1 greenhouse gas emission scenarios to force a Precipitation-Runoff Modeling System (PRMS) watershed model developed for the Lehman and Baker Creeks Drainage (LBCD) in the Great Basin National Park, NV for a century long time period. The goal is to quantify the effects of rising temperature to the water budget in the LBCD at monthly and annual timescales. Dynamically downscaled GCM projections are attained from the NSF EPSCoR Nevada Infrastructure for Climate Change Science, Education, and Outreach project and statistically downscaled output is retrieved from the "U.S. Bias Corrected and Downscaled WCRP CMIP3 Climate Projections". Historical daily climate and streamflow data have been collected simultaneously for periods extending 20 years or longer. Mann-Kendal trend test results showed a statistically significant (α= 0.05) long-term rising trend from 1895 to 2012 in annual and monthly average temperatures for the study area. A grid-based, PRMS watershed model of the LBCD has been created within ArcGIS 10, and physical parameters have been estimated at a spatial resolution of 100m. Simulation results will be available soon. Snow cover is expected to decrease and peak runoff to occur earlier in the spring, resulting in increased runoff, decreased infiltration/recharge, decreased baseflows, and decreased evapo-transpiration.

  7. Baker 10 x 20 NTMS area, Oregon and Idaho: data report (abbreviated)

    International Nuclear Information System (INIS)

    Cook, J.R.

    1981-05-01

    Surface sediment samples were collected at 1426 sites, at a target sampling density of one site per 13 square kilometers. Ground water samples were collected at 460 sites. Neutron activation analysis results are given for uranium and 16 other elements in sediments, and for uranium and 9 other elements in ground water and surface water. Mass spectrometry results are given for helium in ground water. Field measurements and observations are reported for each site. Analytical data and field measurements are presented in tables and maps. Data from ground water and surface water sites include: (1) water chemistry measurements (pH, conductivity, and alkalinity), (2) physical measurements, where applicable (water temperature, well description, and scintillometer reading), and (3) elemental analyses (U, Al, Br, Cl, Dy, F, Mg, Mn, Na, and V). Helium analyses are given for ground water. Data from sediment sites include: (1) stream water chemistry measurements from sites where water was available, and (2) elemental analyses for sediment samples (U, Th, Hf, Al, Ce, Dy, Eu, Fe, La, Lu, Mn, Sc, Sm, Na, Ti, V, and Yb). Sample site descriptors (stream characteristics, vegetation, etc.) are also tabulated. Areal distribution maps, histograms, and cumulative frequency plots for these elements; U/Th, U/Hf, U/(Th + Hf), and U/La ratios; and scintillometer readings at sediment sample sites are included on the microfiche. The maximum uranium concentration found in sediments in the Baker quadrangle was 21.1 ppM. The mean of the logarithms of the uranium concentrations was 0.77. Concentrations of uranium and the rare-earth elements were high along the eastern edge of the quadrangle

  8. When is Deceptive Message Production More Effortful than Truth-Telling? A Baker's Dozen of Moderators.

    Science.gov (United States)

    Burgoon, Judee K

    2015-01-01

    Deception is thought to be more effortful than telling the truth. Empirical evidence from many quarters supports this general proposition. However, there are many factors that qualify and even reverse this pattern. Guided by a communication perspective, I present a baker's dozen of moderators that may alter the degree of cognitive difficulty associated with producing deceptive messages. Among sender-related factors are memory processes, motivation, incentives, and consequences. Lying increases activation of a network of brain regions related to executive memory, suppression of unwanted behaviors, and task switching that is not observed with truth-telling. High motivation coupled with strong incentives or the risk of adverse consequences also prompts more cognitive exertion-for truth-tellers and deceivers alike-to appear credible, with associated effects on performance and message production effort, depending on the magnitude of effort, communicator skill, and experience. Factors related to message and communication context include discourse genre, type of prevarication, expected response length, communication medium, preparation, and recency of target event/issue. These factors can attenuate the degree of cognitive taxation on senders so that truth-telling and deceiving are similarly effortful. Factors related to the interpersonal relationship among interlocutors include whether sender and receiver are cooperative or adversarial and how well-acquainted they are with one another. A final consideration is whether the unit of analysis is the utterance, turn at talk, episode, entire interaction, or series of interactions. Taking these factors into account should produce a more nuanced answer to the question of when deception is more difficult than truth-telling.

  9. Endoplasmic reticulum involvement in yeast cell death

    International Nuclear Information System (INIS)

    Nicanor Austriaco, O.

    2012-01-01

    Yeast cells undergo programed cell death (PCD) with characteristic markers associated with apoptosis in mammalian cells including chromatin breakage, nuclear fragmentation, reactive oxygen species generation, and metacaspase activation. Though significant research has focused on mitochondrial involvement in this phenomenon, more recent work with both Saccharomyces cerevisiae and Schizosaccharomyces pombe has also implicated the endoplasmic reticulum (ER) in yeast PCD. This minireview provides an overview of ER stress-associated cell death (ER-SAD) in yeast. It begins with a description of ER structure and function in yeast before moving to a discussion of ER-SAD in both mammalian and yeast cells. Three examples of yeast cell death associated with the ER will be highlighted here including inositol starvation, lipid toxicity, and the inhibition of N-glycosylation. It closes by suggesting ways to further examine the involvement of the ER in yeast cell death.

  10. Brewing characteristics of piezosensitive sake yeasts

    Science.gov (United States)

    Nomura, Kazuki; Hoshino, Hirofumi; Igoshi, Kazuaki; Onozuka, Haruka; Tanaka, Erika; Hayashi, Mayumi; Yamazaki, Harutake; Takaku, Hiroaki; Iguchi, Akinori; Shigematsu, Toru

    2018-04-01

    Application of high hydrostatic pressure (HHP) treatment to food processing is expected as a non-thermal fermentation regulation technology that supresses over fermentation. However, the yeast Saccharomyces cerevisiae used for Japanese rice wine (sake) brewing shows high tolerance to HHP. Therefore, we aimed to generate pressure-sensitive (piezosensitive) sake yeast strains by mating sake with piezosensitive yeast strains to establish an HHP fermentation regulation technology and extend the shelf life of fermented foods. The results of phenotypic analyses showed that the generated yeast strains were piezosensitive and exhibited similar fermentation ability compared with the original sake yeast strain. In addition, primary properties of sake brewed using these strains, such as ethanol concentration, sake meter value and sake flavor compounds, were almost equivalent to those obtained using the sake yeast strain. These results suggest that the piezosensitive strains exhibit brewing characteristics essentially equivalent to those of the sake yeast strain.

  11. 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.

  12. Oral yeast colonization throughout pregnancy

    OpenAIRE

    Rio, Rute; Sim?es-Silva, Liliana; Garro, Sofia; Silva, M?rio-Jorge; Azevedo, ?lvaro; Sampaio-Maia, Benedita

    2017-01-01

    Background Recent studies suggest that placenta may harbour a unique microbiome that may have origin in maternal oral microbiome. Although the major physiological and hormonal adjustments observed in pregnant women lead to biochemical and microbiological modifications of the oral environment, very few studies evaluated the changes suffered by the oral microbiota throughout pregnancy. So, the aim of our study was to evaluate oral yeast colonization throughout pregnancy and to compare it with n...

  13. 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.

  14. Yeast flocculation: New story in fuel ethanol production.

    Science.gov (United States)

    Zhao, X Q; Bai, F W

    2009-01-01

    Yeast flocculation has been used in the brewing industry to facilitate biomass recovery for a long time, and thus its mechanism of yeast flocculation has been intensively studied. However, the application of flocculating yeast in ethanol production garnered attention mainly in the 1980s and 1990s. In this article, updated research progress in the molecular mechanism of yeast flocculation and the impact of environmental conditions on yeast flocculation are reviewed. Construction of flocculating yeast strains by genetic approach and utilization of yeast flocculation for ethanol production from various feedstocks were presented. The concept of self-immobilized yeast cells through their flocculation is revisited through a case study of continuous ethanol fermentation with the flocculating yeast SPSC01, and their technical and economic advantages are highlighted by comparing with yeast cells immobilized with supporting materials and regular free yeast cells as well. Taking the flocculating yeast SPSC01 as an example, the ethanol tolerance of the flocculating yeast was also discussed.

  15. Morfoanatomia, tricomas glandulares e fitoquímica de Lomatozona artemisiifolia Baker (ASTERACEAE - EUPATORIEAE) - uma planta endêmica do Cerrado de Goiás

    OpenAIRE

    Trindade, Luma Mota Palmeira

    2013-01-01

    Morfoanatomia, tricomas glandulares e fitoquímica de Lomatozona artemisiifolia Baker (Asteraceae - Eupatorieae) – Uma planta endêmica do cerrado de Goiás - A família Asteraceae é amplamente distribuída, possuindo 24.000 espécies e 1.600 a 1700 gêneros, constituindo uma das maiores famílias de fanerógamas. No Cerrado, dentre as fanerógamas, é a segunda maior família em quantidade de espécies. Dentre as inúmeras espécies de Asteraceae está presente Lomatozona artemisiifolia Baker, pertence à tr...

  16. Three-dimensional geophysical mapping of shallow water saturated altered rocks at Mount Baker, Washington: Implications for slope stability

    Science.gov (United States)

    Finn, Carol A.; Deszcz-Pan, Maryla; Ball, Jessica L.; Bloss, Benjamin J.; Minsley, Burke J.

    2018-05-01

    Water-saturated hydrothermal alteration reduces the strength of volcanic edifices, increasing the potential for catastrophic sector collapses that can lead to far traveled and destructive debris flows. Intense hydrothermal alteration significantly lowers the resistivity and magnetization of volcanic rock and therefore hydrothermally altered rocks can be identified with helicopter electromagnetic and magnetic measurements. Geophysical models constrained by rock properties and geologic mapping show that intensely altered rock is restricted to two small (500 m diameter), >150 m thick regions around Sherman Crater and Dorr Fumarole Field at Mount Baker, Washington. This distribution of alteration contrasts with much thicker and widespread alteration encompassing the summits of Mounts Adams and Rainier prior to the 5600 year old Osceola collapse, which is most likely due to extreme erosion and the limited duration of summit magmatism at Mount Baker. In addition, the models suggest that the upper 300 m of rock contains water which could help to lubricate potential debris flows. Slope stability modeling incorporating the geophysically modeled distribution of alteration and water indicates that the most likely and largest ( 0.1 km3) collapses are from the east side of Sherman Crater. Alteration at Dorr Fumarole Field raises the collapse hazard there, but not significantly because of its lower slope angles. Geochemistry and analogs from other volcanoes suggest a model for the edifice hydrothermal system.

  17. Three-dimensional geophysical mapping of shallow water saturated altered rocks at Mount Baker, Washington: Implications for slope stability

    Science.gov (United States)

    Finn, Carol A.; Deszcz-Pan, Maria; Ball, Jessica L.; Bloss, Benjamin J.; Minsley, Burke J.

    2018-01-01

    Water-saturated hydrothermal alteration reduces the strength of volcanic edifices, increasing the potential for catastrophic sector collapses that can lead to far traveled and destructive debris flows. Intense hydrothermal alteration significantly lowers the resistivity and magnetization of volcanic rock and therefore hydrothermally altered rocks can be identified with helicopter electromagnetic and magnetic measurements. Geophysical models constrained by rock properties and geologic mapping show that intensely altered rock is restricted to two small (500 m diameter), >150 m thick regions around Sherman Crater and Dorr Fumarole Field at Mount Baker, Washington. This distribution of alteration contrasts with much thicker and widespread alteration encompassing the summits of Mounts Adams and Rainier prior to the 5600 year old Osceola collapse, which is most likely due to extreme erosion and the limited duration of summit magmatism at Mount Baker. In addition, the models suggest that the upper ~300 m of rock contains water which could help to lubricate potential debris flows. Slope stability modeling incorporating the geophysically modeled distribution of alteration and water indicates that the most likely and largest (~0.1 km3) collapses are from the east side of Sherman Crater. Alteration at Dorr Fumarole Field raises the collapse hazard there, but not significantly because of its lower slope angles. Geochemistry and analogs from other volcanoes suggest a model for the edifice hydrothermal system.

  18. Drosophila Regulate Yeast Density and Increase Yeast Community Similarity in a Natural Substrate

    OpenAIRE

    Stamps, Judy A.; Yang, Louie H.; Morales, Vanessa M.; Boundy-Mills, Kyria L.

    2012-01-01

    Drosophila melanogaster adults and larvae, but especially larvae, had profound effects on the densities and community structure of yeasts that developed in banana fruits. Pieces of fruit exposed to adult female flies previously fed fly-conditioned bananas developed higher yeast densities than pieces of the same fruits that were not exposed to flies, supporting previous suggestions that adult Drosophila vector yeasts to new substrates. However, larvae alone had dramatic effects on yeast densit...

  19. Whey - raw material for the production of baker starter-cultures

    Directory of Open Access Journals (Sweden)

    Jasna Mrvčić

    2008-05-01

    Full Text Available The possibility of production Lactic acid bacteria (LAB, which are suitable for breadmaking on whey was researched and compared to the results achieved in modified MRS medium. The growth and fermentation activities of Leuconostoc meseteroides L-3, Lactobacillus brevis L-62 and Lactobacillus plantarum L-73 were examined by monitoring lactic and acetic acid production in fermentation broth and in sourdough. Presented results show that deproteinized whey is suitable for LAB production. The best biomass yield (1,7 g/L and lactic acid production (9,15 mg/mL was achieved with L. plantarum L-73. Better flavour, elasticity and shelf life of bread made with whey-based starters compared to the classical yeast-monoculture based bread were determined by sensory analysis (DLG method.

  20. YMDB: the Yeast Metabolome Database

    Science.gov (United States)

    Jewison, Timothy; Knox, Craig; Neveu, Vanessa; Djoumbou, Yannick; Guo, An Chi; Lee, Jacqueline; Liu, Philip; Mandal, Rupasri; Krishnamurthy, Ram; Sinelnikov, Igor; Wilson, Michael; Wishart, David S.

    2012-01-01

    The Yeast Metabolome Database (YMDB, http://www.ymdb.ca) is a richly annotated ‘metabolomic’ database containing detailed information about the metabolome of Saccharomyces cerevisiae. Modeled closely after the Human Metabolome Database, the YMDB contains >2000 metabolites with links to 995 different genes/proteins, including enzymes and transporters. The information in YMDB has been gathered from hundreds of books, journal articles and electronic databases. In addition to its comprehensive literature-derived data, the YMDB also contains an extensive collection of experimental intracellular and extracellular metabolite concentration data compiled from detailed Mass Spectrometry (MS) and Nuclear Magnetic Resonance (NMR) metabolomic analyses performed in our lab. This is further supplemented with thousands of NMR and MS spectra collected on pure, reference yeast metabolites. Each metabolite entry in the YMDB contains an average of 80 separate data fields including comprehensive compound description, names and synonyms, structural information, physico-chemical data, reference NMR and MS spectra, intracellular/extracellular concentrations, growth conditions and substrates, pathway information, enzyme data, gene/protein sequence data, as well as numerous hyperlinks to images, references and other public databases. Extensive searching, relational querying and data browsing tools are also provided that support text, chemical structure, spectral, molecular weight and gene/protein sequence queries. Because of S. cervesiae's importance as a model organism for biologists and as a biofactory for industry, we believe this kind of database could have considerable appeal not only to metabolomics researchers, but also to yeast biologists, systems biologists, the industrial fermentation industry, as well as the beer, wine and spirit industry. PMID:22064855

  1. Bacterial Signaling Nucleotides Inhibit Yeast Cell Growth by Impacting Mitochondrial and Other Specifically Eukaryotic Functions.

    Science.gov (United States)

    Hesketh, Andy; Vergnano, Marta; Wan, Chris; Oliver, Stephen G

    2017-07-25

    cells recover. Despite the importance of this process, the broader impact of bacterial nucleotides on the functioning of eukaryotic cells remains poorly defined. To address this, we genetically modified cells of the eukaryote Saccharomyces cerevisiae (baker's yeast) to produce three of these molecules (cdiAMP, cdiGMP, and ppGpp) and used the engineered strains as model systems to characterize the effects of the molecules on the cells. In addition to demonstrating that the nucleotides are each capable of adversely affecting yeast cell function and growth, we also identified the cellular functions important for mitigating the damage caused, suggesting possible modes of action. This study expands our understanding of the molecular interactions that can take place between bacterial and eukaryotic cells. Copyright © 2017 Hesketh et al.

  2. Experimental evolution in budding yeast

    Science.gov (United States)

    Murray, Andrew

    2012-02-01

    I will discuss our progress in analyzing evolution in the budding yeast, Saccharomyces cerevisiae. We take two basic approaches. The first is to try and examine quantitative aspects of evolution, for example by determining how the rate of evolution depends on the mutation rate and the population size or asking whether the rate of mutation is uniform throughout the genome. The second is to try to evolve qualitatively novel, cell biologically interesting phenotypes and track the mutations that are responsible for the phenotype. Our efforts include trying to alter cell morphology, evolve multicellularity, and produce a biological oscillator.

  3. Chemostat Culture for Yeast Physiology.

    Science.gov (United States)

    Kerr, Emily O; Dunham, Maitreya J

    2017-07-05

    The use of chemostat culture facilitates the careful comparison of different yeast strains growing in well-defined conditions. Variations in physiology can be measured by examining gene expression, metabolite levels, protein content, and cell morphology. In this protocol, we show how a combination of sample types can be collected during harvest from a single 20-mL chemostat in a ministat array, with special attention to coordinating the handling of the most time-sensitive sample types. © 2017 Cold Spring Harbor Laboratory Press.

  4. Triosephosphate isomerase: energetics of the reaction catalyzed by the yeast enzyme expressed in Escherichia coli

    International Nuclear Information System (INIS)

    Nickbarg, E.B.; Knowles, J.R.

    1988-01-01

    Triosephosphate isomerase from bakers' yeast, expressed in Escherichia coli strain DF502(p12), has been purified to homogeneity. The kinetics of the reaction in each direction have been determined at pH 7.5 and 30 degrees C. Deuterium substitution at the C-2 position of substrate (R)-glyceraldehyde phosphate and at the 1-pro-R position of substrate dihydroxyacetone phosphate results in kinetic isotope effects on kcat of 1.6 and 3.4, respectively. The extent of transfer of tritium from [1(R)- 3 H]dihydroxyacetone phosphate to product (R)-glyceraldehyde phosphate during the catalyzed reaction is only 3% after 66% conversion to product, indicating that the enzymic base that mediates proton transfer is in rapid exchange with solvent protons. When the isomerase-catalyzed reaction is run in tritiated water in each direction, radioactivity is incorporated both into the remaining substrate and into the product. In the exchange-conversion experiment with dihydroxyacetone phosphate as substrate, the specific radioactivity of remaining dihydroxyacetone phosphate rises as a function of the extent of reaction with a slope of about 0.3, while the specific radioactivity of the products is 54% that of the solvent. In the reverse direction with (R)-glyceraldehyde phosphate as substrate, the specific radioactivity of the product formed is only 11% that of the solvent, while the radioactivity incorporated into the remaining substrate (R)-glyceraldehyde phosphate also rises as a function of the extent of reaction with a slope of 0.3. These results have been analyzed according to the protocol described earlier to yield the free energy profile of the reaction catalyzed by the yeast isomerase

  5. Validation of a predictive model for the growth of chalk yeasts on bread.

    Science.gov (United States)

    Burgain, Anaïs; Bensoussan, Maurice; Dantigny, Philippe

    2015-07-02

    The present study focused on the effects of temperature, T, and water activity, aw, on the growth of Hyphopichia burtonii, Pichia anomala, and Saccharomycopsis fibuligera on Sabouraud Agar Medium. Cardinal values were estimated by means of cardinal models with inflection. All the yeasts were xerophilic, and they exhibited growth at 0.85 aw. The combined effects of T, aw, and pH on the growth of these species were described by the gamma-concept and validated on bread in the range of 15-25 °C, 0.91-0.97 aw, and pH 4.6-6.8. The optimum growth rates on bread were 2.88, 0.259, and 1.06 mm/day for H. burtonii, P. anomala, and S. fibuligera, respectively. The optimal growth rate of S. fibuligera on bread was about 2 fold that obtained on Sabouraud. Due to reproduction by budding, P. anomala exhibited low growth on Sabouraud and bread. However, this species is of major concern in the baker's industry because of the production of ethyl acetate in bread. Copyright © 2015 Elsevier B.V. All rights reserved.

  6. Kinetic analysis and chemical modification studies of nicotinate phosphoribosyltransferase from yeast

    International Nuclear Information System (INIS)

    Hess, S.L.

    1988-01-01

    Nicotinate phosphoribosyltransferase (NaPRTase) from Baker's yeast catalyzes the formation of nicotinate mononucleotide (NaMN) and pyrophosphate from phosphoribosyl α-1-pyrophosphate and nicotinate, concomitant with ATP hydrolysis. Using purified NaPRTase, initial velocity measurements were performed varying one substrate concentration at different fixed levels of the second substrate and maintaining the third substrate constant. Subsequently, an exchange of label was observed between ATP and [ 14 C]-ADP. This rate of exchange was inhibited by PRibPP and pyrophosphate. Incubations of NaPRTase with pyridoxal 5'-phosphate followed by sodium borohydride reduction led to inactivation of the enzyme. Pyridoxal was a less effective inhibitor than pyridoxal 5'-phosphate. The inactivation of the enzyme by pyridoxal 5'-phosphate was reversible upon flow dialysis, whereas reduction of the enzyme-pyridoxal complex with sodium borohydride rendered the inhibition irreversible. The presence of ATP or PRibPP, with or with Mg 2+ , provided protection against this inactivation, while a kinetic analysis revealed the inhibition to be competitive, and noncompetitive, respectively. One mole of [ 3 H]-pyridoxal phosphate was required to completely inactivate the enzyme, which was reduced in the presence of MgATP and MgPRibPP to 0.2 and 0.6, respectively. No incorporation of pyridoxal 5'-phosphate was observed in the combination of both of the two substrates

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

    African Journals Online (AJOL)

    Biodiesel generation from oleaginous yeast Rhodotorula glutinis with xylose assimilating capacity. ... Biodiesel generation from oleaginous yeast Rhodotorula glutinis with xylose assimilating capacity. C Dai, J Tao, F Xie, Y Dai, M Zhao. Abstract. This study explored a strategy to convert agricultural and forestry residues into ...

  8. Yeasts in sustainable bioethanol production: A review.

    Science.gov (United States)

    Mohd Azhar, Siti Hajar; Abdulla, Rahmath; Jambo, Siti Azmah; Marbawi, Hartinie; Gansau, Jualang Azlan; Mohd Faik, Ainol Azifa; Rodrigues, Kenneth Francis

    2017-07-01

    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.

  9. 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.

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

    African Journals Online (AJOL)

    SERVER

    2007-09-19

    Sep 19, 2007 ... 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 ...

  11. 21 CFR 73.355 - Phaffia yeast.

    Science.gov (United States)

    2010-04-01

    ... stabilized color additive mixture. Color additive mixtures for fish feed use made with phaffia yeast may... additive mixtures for coloring foods. (b) Specifications. Phaffia yeast shall conform to the following... § 501.4 of this chapter. (3) The presence of the color additive in salmonid fish that have been fed...

  12. 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 ...

  13. 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.

  14. 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.

  15. [Respiratory allergies among bakers and pastry cooks: epidemiologic survey done in 1991 by the occupational physicians of the Loire-Atlantique].

    Science.gov (United States)

    Anton, M; Bataille, A; Mollat, F; Bobe, M; Bonneau, C; Caramaniam, M N; Géraut, C; Dupas, D

    1995-01-01

    The aim was to study the prevalence of respiratory allergy (rhinitis and asthma) in a population of bakers and pastrycooks. In 1991, 485 bakers and pastry cooks were examined by 27 work-physicians of Loire-Atlantic. The investigation was composed of a standardised questionnaire (signs of respiratory function, atopic history, smoking of tobacco ...), a clinical examination, and tests of respiratory function. An allergy assessment was made of all subjects with symptoms. 14.4% of subjects had rhinitis and 6.4% asthma. Development of these pathologies was clearly job-related for 2/3 of those with rhinitis and more than half of the asthmatics (55%). Occupational rhinitis and asthma were significantly more frequent in bakers than in pastrycooks and were linked to atopic history. Occupational asthma was associated with length of exposure to flour and with occupational rhinitis. In conclusion, these findings are comparable with or a little less than those that have been reported in occupational literature. They under-estimate the importance of the problem because of the occupational selection effect that is associated with these pathologies. Rhinitis and asthma are 1.5 to 3 time more common in bakers than in pastrycooks.

  16. A Reassessment of George Pierce Baker's "The Principles of Argumentation": Minimizing the Use of Formal Logic in Favor of Practical Approaches

    Science.gov (United States)

    Bordelon, Suzanne

    2006-01-01

    In this article, the author demonstrated how recent histories relied primarily on previous accounts and one textbook to characterize George Pierce Baker's work. This narrow assessment of "The Principles of Argumentation" limits one's understanding of his contribution to argumentation theory and pedagogy. Similarly, one has seen the need for care…

  17. The essence of yeast quiescence.

    Science.gov (United States)

    De Virgilio, Claudio

    2012-03-01

    Like all microorganisms, yeast cells spend most of their natural lifetime in a reversible, quiescent state that is primarily induced by limitation for essential nutrients. Substantial progress has been made in defining the features of quiescent cells and the nutrient-signaling pathways that shape these features. A view that emerges from the wealth of new data is that yeast cells dynamically configure the quiescent state in response to nutritional challenges by using a set of key nutrient-signaling pathways, which (1) regulate pathway-specific effectors, (2) converge on a few regulatory nodes that bundle multiple inputs to communicate unified, graded responses, and (3) mutually modulate their competences to transmit signals. Here, I present an overview of our current understanding of the architecture of these pathways, focusing on how the corresponding core signaling protein kinases (i.e. PKA, TORC1, Snf1, and Pho85) are wired to ensure an adequate response to nutrient starvation, which enables cells to tide over decades, if not centuries, of famine. © 2011 Federation of European Microbiological Societies. Published by Blackwell Publishing Ltd. All rights reserved.

  18. Comet assay on tetraploid yeast cells

    DEFF Research Database (Denmark)

    Rank, Jette; Syberg, Kristian; Jensen, Klara

    2009-01-01

    Tetraploid yeast cells (Saccharomyces cerevisiae) were used in the comet assay with the intention of developing a new, fast and easy assay for detecting environmental genotoxic agents without using higher organisms. Two DNA-damaging chemicals, H2O2 and acrylamide, together with wastewater from...... three municipal treatment plants were tested for their effect on the yeast-cell DNA. The main problem with using yeast in the comet assay is the necessity to degrade the cell wall. This was achieved by using Zymolase 100 T twice during the procedure, since Zymolase 20 T did not open the cell wall....... 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...

  19. Electron transport chain in a thermotolerant yeast.

    Science.gov (United States)

    Mejía-Barajas, Jorge A; Martínez-Mora, José A; Salgado-Garciglia, Rafael; Noriega-Cisneros, Ruth; Ortiz-Avila, Omar; Cortés-Rojo, Christian; Saavedra-Molina, Alfredo

    2017-04-01

    Yeasts capable of growing and surviving at high temperatures are regarded as thermotolerant. For appropriate functioning of cellular processes and cell survival, the maintenance of an optimal redox state is critical of reducing and oxidizing species. We studied mitochondrial functions of the thermotolerant Kluyveromyces marxianus SLP1 and the mesophilic OFF1 yeasts, through the evaluation of its mitochondrial membrane potential (ΔΨ m ), ATPase activity, electron transport chain (ETC) activities, alternative oxidase activity, lipid peroxidation. Mitochondrial membrane potential and the cytoplasmic free Ca 2+ ions (Ca 2+ cyt) increased in the SLP1 yeast when exposed to high temperature, compared with the mesophilic yeast OFF1. ATPase activity in the mesophilic yeast diminished 80% when exposed to 40° while the thermotolerant SLP1 showed no change, despite an increase in the mitochondrial lipid peroxidation. The SLP1 thermotolerant yeast exposed to high temperature showed a diminution of 33% of the oxygen consumption in state 4. The uncoupled state 3 of oxygen consumption did not change in the mesophilic yeast when it had an increase of temperature, whereas in the thermotolerant SLP1 yeast resulted in an increase of 2.5 times when yeast were grown at 30 o , while a decrease of 51% was observed when it was exposed to high temperature. The activities of the ETC complexes were diminished in the SLP1 when exposed to high temperature, but also it was distinguished an alternative oxidase activity. Our results suggest that the mitochondria state, particularly ETC state, is an important characteristic of the thermotolerance of the SLP1 yeast strain.

  20. Cryptanalysis and improvement of an optical image encryption scheme using a chaotic Baker map and double random phase encoding

    International Nuclear Information System (INIS)

    Chen, Jun-Xin; Fu, Chong; Zhu, Zhi-Liang; Zhang, Li-Bo; Zhang, Yushu

    2014-01-01

    In this paper, we evaluate the security of an enhanced double random phase encoding (DRPE) image encryption scheme (2013 J. Lightwave Technol. 31 2533). The original system employs a chaotic Baker map prior to DRPE to provide more protection to the plain image and hence promote the security level of DRPE, as claimed. However, cryptanalysis shows that this scheme is vulnerable to a chosen-plaintext attack, and the ciphertext can be precisely recovered. The corresponding improvement is subsequently reported upon the basic premise that no extra equipment or computational complexity is required. The simulation results and security analyses prove its effectiveness and security. The proposed achievements are suitable for all cryptosystems under permutation and, following that, the DRPE architecture, and we hope that our work can motivate the further research on optical image encryption. (paper)

  1. Cryptanalysis and improvement of an optical image encryption scheme using a chaotic Baker map and double random phase encoding

    Science.gov (United States)

    Chen, Jun-Xin; Zhu, Zhi-Liang; Fu, Chong; Zhang, Li-Bo; Zhang, Yushu

    2014-12-01

    In this paper, we evaluate the security of an enhanced double random phase encoding (DRPE) image encryption scheme (2013 J. Lightwave Technol. 31 2533). The original system employs a chaotic Baker map prior to DRPE to provide more protection to the plain image and hence promote the security level of DRPE, as claimed. However, cryptanalysis shows that this scheme is vulnerable to a chosen-plaintext attack, and the ciphertext can be precisely recovered. The corresponding improvement is subsequently reported upon the basic premise that no extra equipment or computational complexity is required. The simulation results and security analyses prove its effectiveness and security. The proposed achievements are suitable for all cryptosystems under permutation and, following that, the DRPE architecture, and we hope that our work can motivate the further research on optical image encryption.

  2. Heat recovery and energy saving using a Baker Perkins Simplex 2000 bread baking oven. A demonstration at Mothers Pride Bakery

    Energy Technology Data Exchange (ETDEWEB)

    1986-02-01

    A report is given of a new bread oven, a Baker Perkins Simplex 2000, installed at British Bakeries' Watnall plant under the Energy Efficiency Demonstration Scheme. The energy saving features include 1) a new design of heating system, 2) combustion air pre-heated with burner flue gases, 3) heat recovery from oven chamber to heat hot water and 4) an in-line lidding system. Results are presented for an independent monitoring of both the new oven and one of a conventional design to compare energy consumption and performance. It is shown that the simplex 2000 reduced energy costs at the Watnall plant by Pound 45,900/year. Additional benefits of the new oven include reduced production labour requirements and an increase in productivity of 100% compared with previous models. (UK).

  3. Determinação de metais em água e folha de AECHMEA BLANCHETIANA (BAKER L.B

    Directory of Open Access Journals (Sweden)

    Jaline R. Ribeiro

    2016-05-01

    Full Text Available The aim of this research was to determine the concentrations of calcium, iron, manganese, zinc, potassium and sodium in the water and leaves of Aechmea blanchetiana (Baker L.B species collected between the cities of Ilhéus and Itacaré, Bahia, Brazil and verify if the metals found in the water can be absorbed by the leaves. Flame atomic absorption spectrometry (F AAS and flame photometry were used for the determination of metals. pH measurements, dissolved oxygen and water temperature were also made. The results obtained were used in an exploratory analysis. Principal component analysis (PCA showed clearly the distinct formation of two clusters and the correlation analysis indicated that the leaves of A. blanchetiana seem to absorb iron, calcium, manganese and zinc from the water tank.

  4. “Show Us Your God”: Marilla Baker Ingalls and the Power of Religious Objects in Nineteenth-Century Burma

    Directory of Open Access Journals (Sweden)

    Alexandra Kaloyanides

    2016-06-01

    Full Text Available This essay examines the unusual evangelical work of Marilla Baker Ingalls, an American Baptist missionary to Burma from 1851–1902. By the time of her death in Burma at the age of 75, Ingalls was known as one of the most successful Baptist evangelists among Burmese Buddhists. To understand the extraordinary dynamic of Ingalls’ expanding Christian community, this essay focuses on two prominent objects at the Baptist mission: A life-sized dog statue that Ingalls kept chained at the edge of her property and a massive banyan tree covered with biblical illustrations and revered by locals as an abode of divine beings. This essay argues that these objects transformed Ingalls’ American Baptist Christianity into a kind of Burmese religion that revolved around revered objects. Through an examination of the particular shrine practices that pulled people into the Baptist mission, this essay reflects on the larger context of religious encounter, conflict, and representation in modernizing Burma.

  5. Species-specific activation of Cu/Zn SOD by its CCS copper chaperone in the pathogenic yeast Candida albicans.

    Science.gov (United States)

    Gleason, Julie E; Li, Cissy X; Odeh, Hana M; Culotta, Valeria C

    2014-06-01

    Candida albicans is a pathogenic yeast of important public health relevance. Virulence of C. albicans requires a copper and zinc containing superoxide dismutase (SOD1), but the biology of C. albicans SOD1 is poorly understood. To this end, C. albicans SOD1 activation was examined in baker's yeast (Saccharomyces cerevisiae), a eukaryotic expression system that has proven fruitful for the study of SOD1 enzymes from invertebrates, plants, and mammals. In spite of the 80% similarity between S. cerevisiae and C. albicans SOD1 molecules, C. albicans SOD1 is not active in S. cerevisiae. The SOD1 appears incapable of productive interactions with the copper chaperone for SOD1 (CCS1) of S. cerevisiae. C. albicans SOD1 contains a proline at position 144 predicted to dictate dependence on CCS1. By mutation of this proline, C. albicans SOD1 gained activity in S. cerevisiae, and this activity was independent of CCS1. We identified a putative CCS1 gene in C. albicans and created heterozygous and homozygous gene deletions at this locus. Loss of CCS1 resulted in loss of SOD1 activity, consistent with its role as a copper chaperone. C. albicans CCS1 also restored activity to C. albicans SOD1 expressed in S. cerevisiae. C. albicans CCS1 is well adapted for activating its partner SOD1 from C. albicans, but not SOD1 from S. cerevisiae. In spite of the high degree of homology between the SOD1 and CCS1 molecules in these two fungal species, there exists a species-specific barrier in CCS-SOD interactions which may reflect the vastly different lifestyles of the pathogenic versus the noninfectious yeast.

  6. Distinct Domestication Trajectories in Top-Fermenting Beer Yeasts and Wine Yeasts.

    Science.gov (United States)

    Gonçalves, Margarida; Pontes, Ana; Almeida, Pedro; Barbosa, Raquel; Serra, Marta; Libkind, Diego; Hutzler, Mathias; Gonçalves, Paula; Sampaio, José Paulo

    2016-10-24

    Beer is one of the oldest alcoholic beverages and is produced by the fermentation of sugars derived from starches present in cereal grains. Contrary to lager beers, made by bottom-fermenting strains of Saccharomyces pastorianus, a hybrid yeast, ale beers are closer to the ancient beer type and are fermented by S. cerevisiae, a top-fermenting yeast. Here, we use population genomics to investigate (1) the closest relatives of top-fermenting beer yeasts; (2) whether top-fermenting yeasts represent an independent domestication event separate from those already described; (3) whether single or multiple beer yeast domestication events can be inferred; and (4) whether top-fermenting yeasts represent non-recombinant or recombinant lineages. Our results revealed that top-fermenting beer yeasts are polyphyletic, with a main clade composed of at least three subgroups, dominantly represented by the German, British, and wheat beer strains. Other beer strains were phylogenetically close to sake, wine, or bread yeasts. We detected genetic signatures of beer yeast domestication by investigating genes previously linked to brewing and using genome-wide scans. We propose that the emergence of the main clade of beer yeasts is related with a domestication event distinct from the previously known cases of wine and sake yeast domestication. The nucleotide diversity of the main beer clade more than doubled that of wine yeasts, which might be a consequence of fundamental differences in the modes of beer and wine yeast domestication. The higher diversity of beer strains could be due to the more intense and different selection regimes associated to brewing. Copyright © 2016 Elsevier Ltd. All rights reserved.

  7. Genomics and the making of yeast biodiversity.

    Science.gov (United States)

    Hittinger, Chris Todd; Rokas, Antonis; Bai, Feng-Yan; Boekhout, Teun; Gonçalves, Paula; Jeffries, Thomas W; Kominek, Jacek; Lachance, Marc-André; Libkind, Diego; Rosa, Carlos A; Sampaio, José Paulo; Kurtzman, Cletus P

    2015-12-01

    Yeasts are unicellular fungi that do not form fruiting bodies. Although the yeast lifestyle has evolved multiple times, most known species belong to the subphylum Saccharomycotina (syn. Hemiascomycota, hereafter yeasts). This diverse group includes the premier eukaryotic model system, Saccharomyces cerevisiae; the common human commensal and opportunistic pathogen, Candida albicans; and over 1000 other known species (with more continuing to be discovered). Yeasts are found in every biome and continent and are more genetically diverse than angiosperms or chordates. Ease of culture, simple life cycles, and small genomes (∼10-20Mbp) have made yeasts exceptional models for molecular genetics, biotechnology, and evolutionary genomics. Here we discuss recent developments in understanding the genomic underpinnings of the making of yeast biodiversity, comparing and contrasting natural and human-associated evolutionary processes. Only a tiny fraction of yeast biodiversity and metabolic capabilities has been tapped by industry and science. Expanding the taxonomic breadth of deep genomic investigations will further illuminate how genome function evolves to encode their diverse metabolisms and ecologies. Copyright © 2015 Elsevier Ltd. All rights reserved.

  8. 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.

  9. 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.

  10. Yeast cell factories on the horizon

    DEFF Research Database (Denmark)

    Nielsen, Jens

    2015-01-01

    For thousands of years, yeast has been used for making beer, bread, and wine. In modern times, it has become a commercial workhorse for producing fuels, chemicals, and pharmaceuticals such as insulin, human serum albumin, and vaccines against hepatitis virus and human papillomavirus. Yeast has also...... 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...

  11. 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... prescribed conditions: (a) The additive is produced by partial hydrolysis of yeast extract (derived from...

  12. Immobilization of yeast cells by radiation-induced polymerization

    International Nuclear Information System (INIS)

    Fujimura, T.; Kaetsu, I.

    1982-01-01

    Radiation-induced polymerization method was applied to the immobilization of yeast cells. The effects of irradiation, cooling and monomer, which are neccessary for polymerization, were recovered completely by subsequent aerobical incubation of yeast cells. The ethanol productive in immobilized yeast cells increased with the increase of aerobical incubation period. The growth of yeast cells in immobilized yeast cells was indicated. The maximum ethanol productivity in immobilized yeast cell system was around three times as much as that in free yeast cell system. (orig.)

  13. Fatty acids from oleaginous yeasts and yeast-like fungi and their potential applications.

    Science.gov (United States)

    Xue, Si-Jia; Chi, Zhe; Zhang, Yu; Li, Yan-Feng; Liu, Guang-Lei; Jiang, Hong; Hu, Zhong; Chi, Zhen-Ming

    2018-02-01

    Oleaginous yeasts, fatty acids biosynthesis and regulation in the oleaginous yeasts and the fatty acids from the oleaginous yeasts and their applications are reviewed in this article. Oleaginous yeasts such as Rhodosporidium toruloides, Yarrowia lipolytica, Rhodotorula mucilaginosa, and Aureobasidium melanogenum, which can accumulate over 50% lipid of their cell dry weight, have many advantages over other oleaginous microorganisms. The fatty acids from the oleaginous yeasts have many potential applications. Many oleaginous yeasts have now been genetically modified to over-produce fatty acids and their derivatives. The most important features of the oleaginous yeasts are that they have special enzymatic systems for enhanced biosynthesis and regulation of fatty acids in their lipid particles. Recently, some oleaginous yeasts such as R. toruloides have been found to have a unique fatty acids synthetase and other oleaginous yeasts such as A. melanogenum have a unique highly reducing polyketide synthase (HR-PKS) involved in the biosynthesis of hydroxyl fatty acids. It is necessary to further enhance lipid biosynthesis using metabolic engineering and explore new applications of fatty acids in biotechnology.

  14. Purification of yeast alcohol dehydrogenase by using immobilized metal affinity cryogels

    Energy Technology Data Exchange (ETDEWEB)

    Akduman, Begüm [Chemistry Department, Adnan Menderes University, Aydın (Turkey); Uygun, Murat [Koçarlı Vocational and Training School, Adnan Menderes University, Aydın (Turkey); Uygun, Deniz Aktaş, E-mail: daktas@adu.edu.tr [Chemistry Department, Adnan Menderes University, Aydın (Turkey); Akgöl, Sinan [Biochemistry Department, Ege University, İzmir (Turkey); Denizli, Adil [Chemistry Department, Hacettepe University, Ankara (Turkey)

    2013-12-01

    (HEMA–GMA)-IDA cryogels were used for the adsorption of alcohol dehydrogenase. • The effects of pH, alcohol dehydrogenase concentration, temperature, and flow rate on adsorption were investigated. • These cryogels were used for the purification of alcohol dehydrogenase from Baker's yeast with a single step.

  15. Purification of yeast alcohol dehydrogenase by using immobilized metal affinity cryogels

    International Nuclear Information System (INIS)

    Akduman, Begüm; Uygun, Murat; Uygun, Deniz Aktaş; Akgöl, Sinan; Denizli, Adil

    2013-01-01

    (HEMA–GMA)-IDA cryogels were used for the adsorption of alcohol dehydrogenase. • The effects of pH, alcohol dehydrogenase concentration, temperature, and flow rate on adsorption were investigated. • These cryogels were used for the purification of alcohol dehydrogenase from Baker's yeast with a single step

  16. Ribosomal DNA sequence heterogeneity reflects intraspecies phylogenies and predicts genome structure in two contrasting yeast species.

    Science.gov (United States)

    West, Claire; James, Stephen A; Davey, Robert P; Dicks, Jo; Roberts, Ian N

    2014-07-01

    The ribosomal RNA encapsulates a wealth of evolutionary information, including genetic variation that can be used to discriminate between organisms at a wide range of taxonomic levels. For example, the prokaryotic 16S rDNA sequence is very widely used both in phylogenetic studies and as a marker in metagenomic surveys and the internal transcribed spacer region, frequently used in plant phylogenetics, is now recognized as a fungal DNA barcode. However, this widespread use does not escape criticism, principally due to issues such as difficulties in classification of paralogous versus orthologous rDNA units and intragenomic variation, both of which may be significant barriers to accurate phylogenetic inference. We recently analyzed data sets from the Saccharomyces Genome Resequencing Project, characterizing rDNA sequence variation within multiple strains of the baker's yeast Saccharomyces cerevisiae and its nearest wild relative Saccharomyces paradoxus in unprecedented detail. Notably, both species possess single locus rDNA systems. Here, we use these new variation datasets to assess whether a more detailed characterization of the rDNA locus can alleviate the second of these phylogenetic issues, sequence heterogeneity, while controlling for the first. We demonstrate that a strong phylogenetic signal exists within both datasets and illustrate how they can be used, with existing methodology, to estimate intraspecies phylogenies of yeast strains consistent with those derived from whole-genome approaches. We also describe the use of partial Single Nucleotide Polymorphisms, a type of sequence variation found only in repetitive genomic regions, in identifying key evolutionary features such as genome hybridization events and show their consistency with whole-genome Structure analyses. We conclude that our approach can transform rDNA sequence heterogeneity from a problem to a useful source of evolutionary information, enabling the estimation of highly accurate phylogenies of

  17. Biological cycle of Tenuipalpus heveae Baker (Acari, Tenuipalpidae on leaflets of three rubber tree clones Ciclo de vida de Tenuipalpus heveae Baker (Acari, Tenuipalpidae em folíolos de três clones de seringueira

    Directory of Open Access Journals (Sweden)

    Reinaldo José Fazzio Feres

    2010-06-01

    Full Text Available Life cycle of Tenuipalpus heveae Baker (Acari, Tenuipalpidae on leaflets from three rubber tree clones. The biological cycle of Tenuipalpus heveae Baker, 1945 (Tenuipalpidae, a potential rubber tree pest mite, was studied by the observation of individuals reared on leaflets of the clones GT 1, PB 235 and RRIM 600, in controlled environmental conditions. Three daily observations were done of 60 eggs on leaflets from each clone in order to verify the development of immature stages and the female oviposition. The fertility life table was constructed based in the collected data. Mites reared on PB 235 had faster rate of development, requiring less time in days, to double its population in number (TD, and had the highest values for egg production, female longevity, net reproductive rate (Ro, intrinsic rate of natural increase (r m and finite rate of increase (λ. Lower reproductive values and the longest time necessary to reach adult stage were recorded for the mites on GT 1. In all studied clones, the deutonymphal phase had the highest viability, while the larval phase had the lowest, highlighted by the survivorship curve that indicated high mortality during this life stage. The clone PB 235 allowed the most suitable conditions for the development of T. heveae, followed by RRIM 600, while GT 1 was the less suitable substratum to rear this mite species.O ciclo de vida de Tenuipalpus heveae Baker, 1945 (Tenuipalpidae, um potencial ácaro-praga da seringueira, foi estudado a partir de indivíduos criados sobre folíolos destacados dos clones GT 1, PB 235 e RRIM 600, em condições controladas. Três observações diárias foram realizadas, acompanhando-se o desenvolvimento de 60 ovos e de sua prole em folíolos de cada um dos clones, para verificação da oviposição das fêmeas e dos estágios de desenvolvimento. A partir dos dados obtidos, foi elaborada uma tabela de vida de fertilidade. Os ácaros criados sobre folíolos de PB 235 apresentaram r

  18. Isolation and identification of radiation resistant yeasts from sea water

    International Nuclear Information System (INIS)

    Park, Jong Cheon; Jeong, Yong Uk; Kim, Du Hong; Jo, Eun A

    2011-12-01

    This study was conducted to isolate radiation-resistant yeasts from sea water for development of application technology of radiation-resistant microorganism. · Isolation of 656 yeasts from sea water and selection of 2 radiation-resistant yeasts (D 10 value >3) · Identification of isolated yeasts as Filobasidium elegans sharing 99% sequence similarity · Characterization of isolated yeast with ability to repair of the DNA damage and membrane integrity to irradiation

  19. Regulatory aspects of methanol metabolism in yeasts

    International Nuclear Information System (INIS)

    Trotsenko, Y.A.; Bystrykh, L.V.; Ubiyvovk, V.M.

    1984-01-01

    Formaldehyde is the first and key intermediate in the metabolism of methylotrophic yeasts since it stands at a branch point of pathways for methanol oxidation and assimilation. Methanol and, formaldehyde are toxic compounds which severely affect the growth rate, yield coefficient, etc., of yeasts. Two questions arise when considering regulation of methanol metabolism in yeasts how a nontoxic level of formaldehyde is maintained in the cell and how the formaldehyde flow is distributed into oxidation and assimilation. To answer these questions we studied the role of GSH, which spontaneously binds formaldehyde, yielding S-hydroxymethylglutathione; in vivo rates of formaldehyde dissimilation and assimilation by using [ 14 C]methanol; profiles of enzymes responsible for production and utilization of formaldehyde; and levels of metabolites affecting dissimilation and assimilation of formaldehyde. All of the experiments were carried out with the methylotrophic yeast Candida boidinii KD1. 19 refs., 4 figs., 1 tab

  20. 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...

  1. 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

  2. yeast transformation of Mucor circinelloides Tieghe

    African Journals Online (AJOL)

    GRACE

    2006-05-02

    May 2, 2006 ... A nested model analysis of variance of growth data of induced yeast .... Figure 2. Mean biomass and relative growth rates of M. circinelloides cultivated in treatments in ..... Pullman B (ed) Frontiers in Physicochemical Biology.

  3. 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.

  4. 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.

  5. Transcriptional Waves in the Yeast Cell Cycle

    OpenAIRE

    Oliva, Anna; Rosebrock, Adam; Ferrezuelo, Francisco; Pyne, Saumyadipta; Chen, Haiying; Skiena, Steve; Futcher, Bruce; Leatherwood, Janet

    2005-01-01

    Many genes are regulated as an innate part of the eukaryotic cell cycle, and a complex transcriptional network helps enable the cyclic behavior of dividing cells. This transcriptional network has been studied in Saccharomyces cerevisiae (budding yeast) and elsewhere. To provide more perspective on these regulatory mechanisms, we have used microarrays to measure gene expression through the cell cycle of Schizosaccharomyces pombe (fission yeast). The 750 genes with the most significant oscillat...

  6. Determination of tritium in wine yeast samples

    International Nuclear Information System (INIS)

    Cotarlea, Monica-Ionela; Paunescu Niculina; Galeriu, D; Mocanu, N.; Margineanu, R.; Marin, G.

    1998-01-01

    Analytical procedures were developed to determine tritium in wine and wine yeast samples. The content of organic compounds affecting the LSC measurement is reduced by fractioning distillation for wine samples and azeotropic distillation/fractional distillation for wine yeast samples. Finally, the water samples were normally distilled with K MO 4 . The established procedures were successfully applied for wine and wine samples from Murfatlar harvests of the years 1995 and 1996. (authors)

  7. 28 June 2012 - Members of the European Brain Council led by President Mary Baker visiting the LHC tunnel at Point 5 with Technology Department Group Leader L. Bottura and CMS experimental area with Run Coordinator M. Chamizo-Llatas.

    CERN Multimedia

    Jean-Claude Gadmer

    2012-01-01

    28 June 2012 - Members of the European Brain Council led by President Mary Baker visiting the LHC tunnel at Point 5 with Technology Department Group Leader L. Bottura and CMS experimental area with Run Coordinator M. Chamizo-Llatas.

  8. The growth of solar radiated yeast

    Energy Technology Data Exchange (ETDEWEB)

    Kraft, T.

    1995-09-01

    This researcher plans to determine if solar radiation affects the growth of yeast. The irradiated yeast was obtained from a sample exposed in space during a Space Shuttle flight of September 9-20, 1994. Further, the control groups were held at: (1) Goddard Space Flight Center (GSFC) in Greenbelt, Maryland; and (2) South Dakota School of Mines and Technology. The procedure used was based on the fact that yeast is most often used in consumable baked goods. Therefore, the yeast was incorporated into a basic Betty Crocker bread recipe. Data was collected by placing measured amounts of dough into sample containers with fifteen minute growth in height measurements collected and recorded. This researcher assumed the viability of yeast to be relative to its ability to produce carbon dioxide gas and cause the dough to rise. As all ingredients and surroundings were equal, this researcher assumed the yeast will produce the only significant difference in data collected. This researcher noted the approximate use date on all sample packages to be prior to arrival and experiment date. All dates equal, it was then assumed each would act in a similar manner of response. This assumption will allow for equally correct data collection.

  9. The growth of solar radiated yeast

    Science.gov (United States)

    Kraft, Tyrone

    1995-01-01

    This researcher plans to determine if solar radiation affects the growth of yeast. The irradiated yeast was obtained from a sample exposed in space during a Space Shuttle flight of September 9-20, 1994. Further, the control groups were held at: (1) Goddard Space Flight Center (GSFC) in Greenbelt, Maryland; and (2) South Dakota School of Mines and Technology. The procedure used was based on the fact that yeast is most often used in consumable baked goods. Therefore, the yeast was incorporated into a basic Betty Crocker bread recipe. Data was collected by placing measured amounts of dough into sample containers with fifteen minute growth in height measurements collected and recorded. This researcher assumed the viability of yeast to be relative to its ability to produce carbon dioxide gas and cause the dough to rise. As all ingredients and surroundings were equal, this researcher assumed the yeast will produce the only significant difference in data collected. This researcher noted the approximate use date on all sample packages to be prior to arrival and experiment date. All dates equal, it was then assumed each would act in a similar manner of response. This assumption will allow for equally correct data collection.

  10. History of genome editing in yeast.

    Science.gov (United States)

    Fraczek, Marcin G; Naseeb, Samina; Delneri, Daniela

    2018-05-01

    For thousands of years humans have used the budding yeast Saccharomyces cerevisiae for the production of bread and alcohol; however, in the last 30-40 years our understanding of the yeast biology has dramatically increased, enabling us to modify its genome. Although S. cerevisiae has been the main focus of many research groups, other non-conventional yeasts have also been studied and exploited for biotechnological purposes. Our experiments and knowledge have evolved from recombination to high-throughput PCR-based transformations to highly accurate CRISPR methods in order to alter yeast traits for either research or industrial purposes. Since the release of the genome sequence of S. cerevisiae in 1996, the precise and targeted genome editing has increased significantly. In this 'Budding topic' we discuss the significant developments of genome editing in yeast, mainly focusing on Cre-loxP mediated recombination, delitto perfetto and CRISPR/Cas. © 2018 The Authors. Yeast published by John Wiley & Sons, Ltd.

  11. Radiodiagnosis of yeast alveolits (a clinicoexperimental study)

    International Nuclear Information System (INIS)

    Amosov, I.S.; Smirnov, V.A.

    1984-01-01

    A clinicoroetgenological study was made of 115 workers engaged in the yeast production for different periods of time. Disorders of the respiration biomechanics were revealed depending on the period of service. These data were obtained as a result of the use of roentgenopneumopolygraphy. An experimental study was conducted to establish the nature of lesions in the bronchopulmonary system in allergic alveolitis. The effect of finely divided yeast dust on the bronchopulmonary system was studied on 132 guinea-pigs usinq microbronchography and morphological examination. As a result of the study it has been established that during the inhalation of yeast dust, notnceable dystrophy of the bronchi develops, the sizes of alveoli enlarge and part of them undergo emphysematous distension with the rupture of the interalveolar septa. In the course of the study, it has been shown that yeast dust is little agreessive, yeast alveolitis develops after many years of work. The clinical symptoms are non-specific and insignificant. X-ray and morphological changes are followed by the physical manifestations of yeast alveolitis

  12. Novel brewing yeast hybrids: creation and application.

    Science.gov (United States)

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

    2017-01-01

    The natural interspecies Saccharomyces cerevisiae × Saccharomyces eubayanus hybrid yeast is responsible for global lager beer production and is one of the most important industrial microorganisms. Its success in the lager brewing environment is due to a combination of traits not commonly found in pure yeast species, principally low-temperature tolerance, and maltotriose utilization. Parental transgression is typical of hybrid organisms and has been exploited previously for, e.g., the production of wine yeast with beneficial properties. The parental strain S. eubayanus has only been discovered recently and newly created lager yeast strains have not yet been applied industrially. A number of reports attest to the feasibility of this approach and artificially created hybrids are likely to have a significant impact on the future of lager brewing. De novo S. cerevisiae × S. eubayanus hybrids outperform their parent strains in a number of respects, including, but not restricted to, fermentation rate, sugar utilization, stress tolerance, and aroma formation. Hybrid genome function and stability, as well as different techniques for generating hybrids and their relative merits are discussed. Hybridization not only offers the possibility of generating novel non-GM brewing yeast strains with unique properties, but is expected to aid in unraveling the complex evolutionary history of industrial lager yeast.

  13. Making Sense of the Yeast Sphingolipid Pathway.

    Science.gov (United States)

    Megyeri, Márton; Riezman, Howard; Schuldiner, Maya; Futerman, Anthony H

    2016-12-04

    Sphingolipids (SL) and their metabolites play key roles both as structural components of membranes and as signaling molecules. Many of the key enzymes and regulators of SL metabolism were discovered using the yeast Saccharomyces cerevisiae, and based on the high degree of conservation, a number of mammalian homologs were identified. Although yeast continues to be an important tool for SL research, the complexity of SL structure and nomenclature often hampers the ability of new researchers to grasp the subtleties of yeast SL biology and discover new modulators of this intricate pathway. Moreover, the emergence of lipidomics by mass spectrometry has enabled the rapid identification of SL species in yeast and rendered the analysis of SL composition under various physiological and pathophysiological conditions readily amenable. However, the complex nomenclature of the identified species renders much of the data inaccessible to non-specialists. In this review, we focus on parsing both the classical SL nomenclature and the nomenclature normally used during mass spectrometry analysis, which should facilitate the understanding of yeast SL data and might shed light on biological processes in which SLs are involved. Finally, we discuss a number of putative roles of various yeast SL species. Copyright © 2016 Elsevier Ltd. All rights reserved.

  14. 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.

  15. Flor Yeast: New Perspectives Beyond Wine Aging

    Science.gov (United States)

    Legras, Jean-Luc; Moreno-Garcia, Jaime; Zara, Severino; Zara, Giacomo; Garcia-Martinez, Teresa; Mauricio, Juan C.; Mannazzu, Ilaria; Coi, Anna L.; Bou Zeidan, Marc; Dequin, Sylvie; Moreno, Juan; Budroni, Marilena

    2016-01-01

    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 aging 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 velum or flor. This behavior 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 remodeling 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 immobilization within a fungal hyphae framework, will be discussed. PMID:27148192

  16. Spermidine cures yeast of prions

    Directory of Open Access Journals (Sweden)

    Shaun H. Speldewinde

    2015-12-01

    Full Text Available Prions are self-perpetuating amyloid protein aggregates which underlie various neurodegenerative diseases in mammals. The molecular basis underlying their conversion from a normally soluble protein into the prion form remains largely unknown. Studies aimed at uncovering these mechanism(s are therefore essential if we are to develop effective therapeutic strategies to counteract these disease-causing entities. Autophagy is a cellular degradation system which has predominantly been considered as a non-selective bulk degradation process which recycles macromolecules in response to starvation conditions. We now know that autophagy also serves as a protein quality control mechanism which selectively degrades protein aggregates and damaged organelles. These are commonly accumulated in various neurodegenerative disorders including prion diseases. In our recent study [Speldewinde et al. Mol. Biol. Cell. (2015] we used the well-established yeast [PSI+]/Sup35 and [PIN­+]/Rnq1 prion models to show that autophagy prevents sporadic prion formation. Importantly, we found that spermidine, a polyamine that has been used to increase autophagic flux, acts as a protective agent which prevents spontaneous prion formation.

  17. Estudios sobre semilla de Hypochaeris variegata L. (Baker: aceite seminal y harina residual de extracción

    Directory of Open Access Journals (Sweden)

    Nolasco, S. M.

    2000-08-01

    Full Text Available Seeds from Hypochaeris variegata L. (Baker harvested at Olavarría (Buenos Aires, Argentine were defatted with hexane and the raw oil obtained with a yield of 24,7% dry basis. The crude oil was examined in their physicochemical characteristics had refractive index of 1,4637 (at 25ºC, iodine value of 125,2, saponification index of 188,4, unsaponifiable matter of 8,5 % and free fatty acid content of 9,7 (mg KOH/g. Gas chromatographic analysis of the oil revealed high levels of linoleic acid (66,2%, appreciable amount of linolenic and erucic acids. The residual seed meal contained 35,49% of crude protein and 35,1% of crude fiber. Total and phytic acid phosphorous, calcium, ash, sugar and polisaccharides (non presence of starch contents are reported.Semillas de Hypochaeris variegata L. (Baker cosechadas en Olavarría (prov. de Buenos Aires, Argentina se extrajeron con hexano (soxhlet obteniéndose el aceite crudo con un rendimiento del 24,7 % (b.s. y la harina residual de extracción. El aceite crudo se examinó en sus características fisicoquímicas (Indice de refracción: 1.4637 (a 25ºC, Indice de iodo: 125,2, Indice de saponificación: 188,4, insaponificable: 8,5%, Indice de acidez: 9,7 (mgKOH/g y composición acídica. El análisis por cromatografía gaseosa de los ésteres metílicos revela un alto porcentaje de ácido linoleico (66,2%, cantidades apreciables de ácido linolénico y erúcico. La harina residual de extracción presentó un 35,49% b.s. de proteína cruda y 35,1% b.s. de fibra cruda. Se informan valores de fósforo total y de ácido fítico, cenizas, calcio e hidratos de carbono.

  18. The Baker system for nuclear access authorization screening: a psychologically developed system for access screening of vendor and owner applicants at nuclear power plants

    International Nuclear Information System (INIS)

    Baker, E.G.; Crouter, F.L.

    1985-01-01

    This paper presents a comprehensive screening program for unescorted access which has proven to be highly effective in determining the intergrity, trustworthiness, socialibility, behaviors and tendencies of an employee applicant--past, present and future. This procedure, designed specifically for the nuclear industry, can be used with owner or vendor applicants, and meets or exceeds all of the NRC's requirements. The Baker system has been used for nuclear selection since 1979

  19. NetPhosYeast: prediction of protein phosphorylation sites in yeast

    DEFF Research Database (Denmark)

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

    2007-01-01

    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...

  20. 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.

  1. 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

  2. Increasing the yeast yield in alcohol fermentation

    Energy Technology Data Exchange (ETDEWEB)

    Pelc, A; Vamos, E; Varga, L; Gavalya, S; Dolanszky, F

    1964-02-01

    The yeast and ethanol yields (the latter being based on the substrate) are enhanced by adding the substrate (molasses) gradually to the suspension of inoculating yeast during the main fermentation period, passing air through the mash, ceasing both substrate addition and aeration at the end of the main period, and allowing the process to come to an end. This way 12 to 14 kg yeast (dry weight)/100 l ethanol could be obtained within 16 to 24 hours and the yeast obtained could be used as the inoculum for the next charge. For example: 11 to 16 kg yeast (or 18 to 25 l yeast suspension from the preceding charge, containing 18 to 20% dry matter) is kept in 30 to 35 l H/sub 2/SO/sub 4/ (0.74 g/100 ml) for 1 hour, diluted with H/sub 2/O and 30 kg sterile molasses to 300 l, kept at 30 to 32/sup 0/ with mild aeration for 2 hours, 1900 l 30/sup 0/ H/sub 2/O added, then 1 m/sup 3/ air/m/sup 2//hour is passed through the mixture, with the addition of 270 kg sterile molasses, and a solution of 8 kg superphosphate and 5 kg (NH/sub 4/)/sub 2/SO/sub 4/ in 100 l H/sub 2/O, the latter being added in 5 portions over 2 hours. Molasses (600 kg) is added during the main period, maintaining the pH at 5 (H/sub 2/SO/sub 4/), and the temperature at 30/sup 0/, then aeration is ceased and the mixture kept until fermentation proceeds. The 3000 l medium contains 9.6% ethanol and 1.38% yeast, respectively.

  3. Schizosaccharomyces japonicus: the fission yeast is a fusion of yeast and hyphae.

    Science.gov (United States)

    Niki, Hironori

    2014-03-01

    The clade of Schizosaccharomyces includes 4 species: S. pombe, S. octosporus, S. cryophilus, and S. japonicus. Although all 4 species exhibit unicellular growth with a binary fission mode of cell division, S. japonicus alone is dimorphic yeast, which can transit from unicellular yeast to long filamentous hyphae. Recently it was found that the hyphal cells response to light and then synchronously activate cytokinesis of hyphae. In addition to hyphal growth, S. japonicas has many properties that aren't shared with other fission yeast. Mitosis of S. japonicas is referred to as semi-open mitosis because dynamics of nuclear membrane is an intermediate mode between open mitosis and closed mitosis. Novel genetic tools and the whole genomic sequencing of S. japonicas now provide us with an opportunity for revealing unique characters of the dimorphic yeast. © 2013 The Author. Yeast Published by John Wiley & Sons Ltd.

  4. Terroir of yeasts? – Application of FTIR spectroscopy and molecular methods for strain typing of yeasts

    Directory of Open Access Journals (Sweden)

    Gerhards Daniel

    2015-01-01

    Full Text Available The site specific influence on wine (Terroir is an often by wine producers, consumers and scientists discussed topic in the world of wine. A study on grapes and (spontaneous fermentations from six different vineyards was done to investigate the biodiversity of yeasts and to answer the question if there is a terroir of yeast and how it could be influenced. Randomly isolated yeasts were identified by FTIR-spectroscopy and molecular methods on species and strain level. Vineyard specific yeast floras would be observed but they are not such important as expected. Only a few overlapping strain patterns would be identified during both vintages. The yeast flora of the winery had a huge impact on the spontaneous fermentations, but is not really constant and influenced by different factors from outside.

  5. Closed form of the Baker-Campbell-Hausdorff formula for the generators of semisimple complex Lie algebras

    International Nuclear Information System (INIS)

    Matone, Marco

    2016-01-01

    Recently it has been introduced an algorithm for the Baker-Campbell-Hausdorff (BCH) formula, which extends the Van-Brunt and Visser recent results, leading to new closed forms of BCH formula. More recently, it has been shown that there are 13 types of such commutator algebras. We show, by providing the explicit solutions, that these include the generators of the semisimple complex Lie algebras. More precisely, for any pair, X, Y of the Cartan-Weyl basis, we find W, linear combination of X, Y, such that exp(X) exp(Y) = exp(W). The derivation of such closed forms follows, in part, by using the above mentioned recent results. The complete derivation is provided by considering the structure of the root system. Furthermore, if X, Y, and Z are three generators of the Cartan-Weyl basis, we find, for a wide class of cases, W, a linear combination of X, Y and Z, such that exp(X) exp(Y) exp(Z) = exp(W). It turns out that the relevant commutator algebras are type 1c-i, type 4 and type 5. A key result concerns an iterative application of the algorithm leading to relevant extensions of the cases admitting closed forms of the BCH formula. Here we provide the main steps of such an iteration that will be developed in a forthcoming paper. (orig.)

  6. Identificación de fructooligosacáridos e inulinas en residuos de hojas de fique - Furcraea macrophylla Baker

    Directory of Open Access Journals (Sweden)

    Claudia Sofia Guevara Apraez

    2015-10-01

    Full Text Available Colombia es un importante productor de cabuya, fibra natural extraída de fique (Furcraea macrophylla Baker. La explotación de esta planta se caracteriza por productos y procesos tradicionales, poco tecnificados, de bajo valor agregado y con un aprovechamiento limitado de la planta de fique, lo que se traduce en baja rentabilidad. No obstante, en los residuos de este proceso agroindustrial se encuentran muchas sustancias de interés, aun sin explorar, entre ellas los carbohidratos, específicamente los fructanos, como la inulina y los fructooligosacaridos (FOS que son polímeros de fructosa considerados fibra dietaría y que por sus características se clasifican como prebióticos. En esta investigación se evidenció la presencia de FOS e inulinas en los residuos obtenidos durante el proceso de desfibrado de las hojas de fique a través de técnicas enzimáticas y espectro-fotométricas. Debido a las amplias aplicaciones en el sector alimentario se recomienda su cuantificación, extracción y caracterización con el fin de proporcionar valor agregado a través de la explotación de estos compuestos.

  7. Closed form of the Baker-Campbell-Hausdorff formula for the generators of semisimple complex Lie algebras

    Energy Technology Data Exchange (ETDEWEB)

    Matone, Marco [Universita di Padova, Dipartimento di Fisica e Astronomia ' ' G. Galilei' ' , Padua (Italy); Istituto Nazionale di Fisica Nucleare, Sezione di Padova, Padua (Italy)

    2016-11-15

    Recently it has been introduced an algorithm for the Baker-Campbell-Hausdorff (BCH) formula, which extends the Van-Brunt and Visser recent results, leading to new closed forms of BCH formula. More recently, it has been shown that there are 13 types of such commutator algebras. We show, by providing the explicit solutions, that these include the generators of the semisimple complex Lie algebras. More precisely, for any pair, X, Y of the Cartan-Weyl basis, we find W, linear combination of X, Y, such that exp(X) exp(Y) = exp(W). The derivation of such closed forms follows, in part, by using the above mentioned recent results. The complete derivation is provided by considering the structure of the root system. Furthermore, if X, Y, and Z are three generators of the Cartan-Weyl basis, we find, for a wide class of cases, W, a linear combination of X, Y and Z, such that exp(X) exp(Y) exp(Z) = exp(W). It turns out that the relevant commutator algebras are type 1c-i, type 4 and type 5. A key result concerns an iterative application of the algorithm leading to relevant extensions of the cases admitting closed forms of the BCH formula. Here we provide the main steps of such an iteration that will be developed in a forthcoming paper. (orig.)

  8. The flexible feedstock concept in Industrial Biotechnology: Metabolic engineering of Escherichia coli, Corynebacterium glutamicum, Pseudomonas, Bacillus and yeast strains for access to alternative carbon sources.

    Science.gov (United States)

    Wendisch, Volker F; Brito, Luciana Fernandes; Gil Lopez, Marina; Hennig, Guido; Pfeifenschneider, Johannes; Sgobba, Elvira; Veldmann, Kareen H

    2016-09-20

    Most biotechnological processes are based on glucose that is either present in molasses or generated from starch by enzymatic hydrolysis. At the very high, million-ton scale production volumes, for instance for fermentative production of the biofuel ethanol or of commodity chemicals such as organic acids and amino acids, competing uses of carbon sources e.g. in human and animal nutrition have to be taken into account. Thus, the biotechnological production hosts E. coli, C. glutamicum, pseudomonads, bacilli and Baker's yeast used in these large scale processes have been engineered for efficient utilization of alternative carbon sources. This flexible feedstock concept is central to the use of non-glucose second and third generation feedstocks in the emerging bioeconomy. The metabolic engineering efforts to broaden the substrate scope of E. coli, C. glutamicum, pseudomonads, B. subtilis and yeasts to include non-native carbon sources will be reviewed. Strategies to enable simultaneous consumption of mixtures of native and non-native carbon sources present in biomass hydrolysates will be summarized and a perspective on how to further increase feedstock flexibility for the realization of biorefinery processes will be given. Copyright © 2016 Elsevier B.V. All rights reserved.

  9. Protein patterns of yeast during sporulation

    International Nuclear Information System (INIS)

    Litske Petersen, J.G.; Kielland-Brandt, M.C.; Nilsson-Tillgren, T.

    1979-01-01

    High resolution two-dimensional gel electrophoresis was used to study protein synthesis during synchronous meiosis and ascospore formation of Saccharomyces cerevisiae. The stained protein patterns of samples harvested at any stage between meiotic prophase and the four-spore stage in two sporulating strains showed the same approximately 250 polypeptides. Of these only a few seemed to increase or decrease in concentration during sporulation. The characteristic pattern of sporulating yeast was identical to the pattern of glucose-grown staitonary yeast cells adapted to respiration. The latter type of cells readily initiates meiosis when transferred to sporulation medium. This pattern differed from the protein patterns of exponentially growing cells in glucose or acetate presporulation medium. Five major proteins in stationary and sporulating yeast cells were not detected in either type of exponential culture. Two-dimensional autoradiograms of [ 35 S]methionine-labelled yeast proteins revealed that some proteins were preferentially labelled during sporulation, while other proteins were labelled at later stages. These patterns differed from the auroradiograms of exponentially growing yeast cells in glucose presporulation medium in a number of spots. No differences were observed when stained gels or autoradiograms of sporulating cultures and non-sporulating strains in sporulation medium were compared. (author)

  10. Preliminary geochemical assessment of water in selected streams, springs, and caves in the Upper Baker and Snake Creek drainages in Great Basin National Park, Nevada, 2009

    Science.gov (United States)

    Paul, Angela P.; Thodal, Carl E.; Baker, Gretchen M.; Lico, Michael S.; Prudic, David E.

    2014-01-01

    Water in caves, discharging from springs, and flowing in streams in the upper Baker and Snake Creek drainages are important natural resources in Great Basin National Park, Nevada. Water and rock samples were collected from 15 sites during February 2009 as part of a series of investigations evaluating the potential for water resource depletion in the park resulting from the current and proposed groundwater withdrawals. This report summarizes general geochemical characteristics of water samples collected from the upper Baker and Snake Creek drainages for eventual use in evaluating possible hydrologic connections between the streams and selected caves and springs discharging in limestone terrain within each watershed.Generally, water discharging from selected springs in the upper Baker and Snake Creek watersheds is relatively young and, in some cases, has similar chemical characteristics to water collected from associated streams. In the upper Baker Creek drainage, geochemical data suggest possible hydrologic connections between Baker Creek and selected springs and caves along it. The analytical results for water samples collected from Wheelers Deep and Model Caves show characteristics similar to those from Baker Creek, suggesting a hydrologic connection between the creek and caves, a finding previously documented by other researchers. Generally, geochemical evidence does not support a connection between water flowing in Pole Canyon Creek to that in Model Cave, at least not to any appreciable extent. The water sample collected from Rosethorn Spring had relatively high concentrations of many of the constituents sampled as part of this study. This finding was expected as the water from the spring travelled through alluvium prior to being discharged at the surface and, as a result, was provided the opportunity to interact with soil minerals with which it came into contact. Isotopic evidence does not preclude a connection between Baker Creek and the water discharging from

  11. Use of Saccharomyces cerevisiae yeasts in the chemo selective bioreduction of (1E,4E)-1,5-bis(4-methoxyphenyl)-1,4-pentadien-3-one in biphasic system

    Energy Technology Data Exchange (ETDEWEB)

    Schaefer, Cesar A.; Silva, Vanessa D.; Nascimento, Maria da G., E-mail: maria.nascimento@ufsc.br [Departamento de Quimica, Universidade Federal de Santa Catarina, Florianopolis-SC (Brazil); Stambuk, Boris U. [Departamento de Bioquimica, Universidade Federal de Santa Catarina, Florianopolis-SC (Brazil)

    2013-07-15

    This work describes the chemoselective bioreduction of (1E,4E)-1,5-bis(4-methoxyphenyl)- 1,4-pentadien-3-one (1) mediated by baker's yeast (BY, Saccharomyces cerevisiae cells) in an aqueous/organic solvent biphasic system. The biotransformation of this compound was chemoselective and formed only the corresponding saturated ketone 1,5-bis(4-methoxyphenyl)- 3-pentanone (2). The influence of various factors which may alter the bioreduction of 1, such as the type and percentage of co-solvents, use of six different S. cerevisiae yeast samples (four commercial and two industrial), variations in the substrate and yeast concentrations, temperature, pH and volume of aqueous and organic phases, was investigated. The best reaction conditions were 66.7 g L{sup -1} of Fleischmann BY, 8.3 Multiplication-Sign 10{sup -3} mol L{sup -1} of substrate, pH 6.5 at 35 deg C in the presence of 2.5% (v/v) of N,N-dimethyl sulfoxide (DMSO) as an additive and a V{sub aq}/V{sub org} ratio of 70/30. Under these conditions, the product 2 was recovered in conversions of 82% in 5 h reaction. (author)

  12. Yeast genetics. A manual of methods

    Energy Technology Data Exchange (ETDEWEB)

    Spencer, J.F.T.; Spencer, D.M.; Bruce, I.J.

    1989-01-01

    This is a bench-top manual of methods needed both for classical genetics as related to yeasts, such as mating, sporulation, isolation of hybrids, microdissection of asci for the isolation of single-spore clones, as well as for mapping of genes and the construction of new strains by protoplast fusion. Special emphasis is on mutations in general, and on methods of isolating a number of important classes of mutants in particular. Basic techniques for the separation of chromosomes by electrophoresis, such as OFAGE, FIGE, and CHEF, are discussed, with detailed protocols for the first two. Furthermore, new methods, e.g. for the isolation of high molecular weight DNA from yeast, isolation of RNA, and techniques for transformation of yeasts, are also described in detail. (orig.) With 10 figs.

  13. Modeling diauxic glycolytic oscillations in yeast

    DEFF Research Database (Denmark)

    Hald, Bjørn Olav; Sørensen, Preben Graae

    2010-01-01

    for investigations of central metabolism dynamics of yeast cells. We have previously proposed a model for the open system comprised of the primary fermentative reactions in yeast that quantitatively describes the oscillatory dynamics. However, this model fails to describe the transient behavior of metabolic......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....... Experimental and computational results strongly suggest that regulation of acetaldehyde explains the observed behavior. We have extended the original model with regulation of pyruvate decarboxylase, a reversible alcohol dehydrogenase, and drainage of pyruvate. Using the method of time rescaling in the extended...

  14. [Urinary infection by Saccharomyces cerevisiae: Emerging yeast?].

    Science.gov (United States)

    Elkhihal, B; Elhalimi, M; Ghfir, B; Mostachi, A; Lyagoubi, M; Aoufi, S

    2015-12-01

    Saccharomyces cerevisiae is a commensal yeast of the digestive, respiratory and genito-urinary tract. It is widely used as a probiotic for the treatment of post-antibiotic diarrhea. It most often occurs in immunocompromised patients frequently causing fungemia. We report the case of an adult diabetic patient who had a urinary tract infection due to S. cerevisiae. The disease started with urination associated with urinary frequency burns without fever. The diagnosis was established by the presence of yeasts on direct examination and positivity of culture on Sabouraud-chloramphenicol three times. The auxanogramme gallery (Auxacolor BioRad(®)) allowed the identification of S. cerevisiae. The patient was put on fluconazole with good outcome. This observation points out that this is an opportunistic yeast in immunocompromised patients. Copyright © 2015 Elsevier Masson SAS. All rights reserved.

  15. Structural Studies of the Yeast Mitochondrial Degradosome

    DEFF Research Database (Denmark)

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

    The yeast mitochondrial degradosome/exosome (mtExo) is responsible for most RNA turnover in mitochondria and has been proposed to form a central part of a mitochondrial RNA surveillance system responsible for degradation of aberrant and unprocessed RNA ([1], [2]). In contrast to the cytoplasmic...... 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 and Suv3p from the fission yeast, Schizosaccharomyces pombe, have been cloned for heterologous expression in E. coli. Of the two, we have succeeded in purifying the 73kDa Suv3p by Ni2+-affinity chromatography followed by cleavage of the N-terminal His-tag, cation exchange, and gel filtration. Crystals...

  16. 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...... as well as identify mechanisms underlying human metabolic diseases. Here we collect functional phosphorylation events of 41 enzymes involved in yeast metabolism and demonstrate functional mechanisms and the application of this information in metabolic engineering. From a systems biology perspective, we...... 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...

  17. 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......Ethanol production for use as a biofuel is mainly achieved through simultaneous saccharification and fermentation by yeast. Operating at ≥40°C would be beneficial in terms of increasing efficiency of the process and reducing costs, but yeast does not grow efficiently at those temperatures. We used...... desaturase gene, and increased expression of genes involved in sterol biosynthesis. Additionally, large chromosome III rearrangements and mutations in genes associated with DNA damage and respiration were found, but contributed less to the thermotolerant phenotype....

  18. 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...

  19. Metallic Biosorption Using Yeasts in Continuous Systems

    Directory of Open Access Journals (Sweden)

    Karla Miriam Hernández Mata

    2013-01-01

    Full Text Available Mining effluents were found to be the main source of pollution by heavy metals of the surface water in the San Pedro River in Sonora, Mexico. The overall objective of this study was to determine the biosorption of Zn, Cu, Mn, and Fe with yeasts isolated from San Pedro River in a continuous system. The tests conducted in two reactors packed with zeolite connected in series. The first reactor was inoculated mixing two yeasts species, and the effluent of the first reactor was fed to second reactor. Subsequently, the first reactor was fed with contaminated water of San Pedro River and effluent from this was the second reactor influent. After 40 days of the experiment a reduction of 81.5% zinc, 76.5% copper, manganese 95.5%, and 99.8% of iron was obtained. These results show that the selected yeasts are capable of biosorbing zinc, copper, manganese, and iron under these conditions.

  20. 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.

  1. New yeasts-new brews: modern approaches to brewing yeast design and development.

    Science.gov (United States)

    Gibson, B; Geertman, J-M A; Hittinger, C T; Krogerus, K; Libkind, D; Louis, E J; Magalhães, F; Sampaio, J P

    2017-06-01

    The brewing industry is experiencing a period of change and experimentation largely driven by customer demand for product diversity. This has coincided with a greater appreciation of the role of yeast in determining the character of beer and the widespread availability of powerful tools for yeast research. Genome analysis in particular has helped clarify the processes leading to domestication of brewing yeast and has identified domestication signatures that may be exploited for further yeast development. The functional properties of non-conventional yeast (both Saccharomyces and non-Saccharomyces) are being assessed with a view to creating beers with new flavours as well as producing flavoursome non-alcoholic beers. The discovery of the psychrotolerant S. eubayanus has stimulated research on de novo S. cerevisiae × S. eubayanus hybrids for low-temperature lager brewing and has led to renewed interest in the functional importance of hybrid organisms and the mechanisms that determine hybrid genome function and stability. The greater diversity of yeast that can be applied in brewing, along with an improved understanding of yeasts' evolutionary history and biology, is expected to have a significant and direct impact on the brewing industry, with potential for improved brewing efficiency, product diversity and, above all, customer satisfaction. © FEMS 2017. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  2. Variações na morfoanatomia foliar de Aechmea lindenii (E. Morren Baker var. lindenii (Bromeliaceae sob distintas condições ambientais Leaf morphoanatomy variation in Aechmea lindenii (E. Morren Baker var. lindenii (Bromeliaceae under distinct environmental conditions

    Directory of Open Access Journals (Sweden)

    Caroline Heinig Voltolini

    2011-03-01

    Full Text Available Aechmea lindenii (E. Morren Baker var. lindenii (Bromeliaceae-Bromelioideae ocorre em restingas e Floresta Pluvial de Encosta Atlântica em Santa Catarina e Nordeste do Rio Grande do Sul, BR. Pode ser encontrada total ou parcialmente exposta à irradiação solar e em distintas formas de vida - terrícola, rupícola e epifítica. O objetivo deste trabalho foi comparar morfoanatomicamente às características de folhas de A. lindenii var. lindenii em distintas condições ambientais. Foram coletadas, na Ilha de Santa Catarina (Florianópolis, SC, folhas de plantas terrícolas em restinga herbácea (alta irradiação solar, rupícolas de costões rochosos (alta irradiação solar, terrícolas e epifíticas de sub-bosques (baixa irradiação solar de restinga arbórea e rupícolas de sub-bosque (baixa irradiação solar de Floresta Pluvial de Encosta Atlântica. Foram mensurados comprimento, largura, área da lâmina e bainha foliar, densidade estomática, comprimento e largura das células-guarda, espessura total e das estruturas constituintes na lâmina foliar. As características anatômicas qualitativas são semelhantes nas distintas condições analisadas. A baixa irradiação solar determina maior expansão da área foliar, decorrente do alongamento da lâmina. Lâmina e bainha foliares têm maior largura sob alta irradiação. A densidade estomática foi maior em folhas de plantas sob alta irradiação solar. A espessura total da lâmina foliar foi menor em plantas terrícolas sob alta irradiação, porém não mostrou diferenças estatísticas significativas entre as outras condições.Aechmea lindenii (E. Morren Baker var. lindenii (Bromeliaceae-Bromelioideae occurs in restingas and hillside Atlantic rain forest in Santa Catarina and northeastern Rio Grande do Sul, Brazil. It is found totally or partially exposed to solar radiation and in different life forms - terricolous, rupicolous and epiphytes. The aim of this work was to compare

  3. Produção de frutanos em calos e plântulas clonadas in vitro de Viguiera discolor Baker (Asteraceae Fructan production in callus and in vitro cloned seedlings of Viguiera discolor Baker (Asteraceae

    Directory of Open Access Journals (Sweden)

    Nair Massumi Itaya

    2005-09-01

    Full Text Available Viguiera discolor Baker é uma espécie nativa do cerrado, cuja sobrevivência está ameaçada pela invasão de espécies exóticas. Considerando sua elevada produção e a vasta aplicação de frutanos, o presente trabalho foi conduzido visando à obtenção in vitro dessa espécie e à prospecção desses carboidratos nessas condições. Sementes foram germinadas in vitro, em meio MS modificado, e após cinco semanas de incubação, nós caulinares foram isolados e incubados no mesmo meio adicionado de 0,5 mg L-1 de ANA, regenerando plantas uniformes, raízesnão espessadas, raízes tuberosas e estruturas semelhantes a calo (calo tipo1, formadas na região caulinar basal. Análise desse material evidenciou a presença de frutanos do tipo inulina nas raízes tuberosas e nos calos tipo 1. Na presença de 2,4-D obteve-se a formação de calos friáveis (calo tipo 2, nos quais também foram detectados frutanos e suas enzimas de síntese sacarose: sacarose 1-frutosiltransferase (SST e frutano: frutano 1-frutosiltransferase (FFT. Embora em concentrações menores às observadas nas plantas cultivadas sob condições naturais, o material produzido in vitro apresentou frutanos do mesmo tipo e razão SST/FFT menor do que um. Em meio de cultura sem hormônios, foi verificada a regeneração de 50% de plantas a partir dos nós caulinares. A propagação de V. discolor in vitro pode viabilizar a multiplicação e a preservação da espécie, bem como a produção de frutanos nessas condições.Viguiera discolor Baker is a herbaceous species, native to cerrado and its survival has been threatened by the invasion of exotic species. Considering its high production and the wide application of fructans, the present work has aimed to establish in vitro culture of this species and to investigate the presence of fructans under these conditions. Seeds were germinated in vitro on modified MS medium and after plant growth, stem nodes were isolated and incubated on

  4. Effect of the gamma radiation on the chemical, rheological, baker and microbiological properties in wheat flour; Efecto de la radiacion gama sobre las propiedades quimicas, reologicas, panaderas y microbiologicas en harina de trigo

    Energy Technology Data Exchange (ETDEWEB)

    Agundez A, Z; Fernandez R, M V [Departamento de Ciencias Quimico Biologicas, Universidad de Sonora, Hermosillo (Mexico); Arce C, M E; Cruz Z, E [Instituto de Ciencias Nucleares, UNAM, 04510 Mexico D.F. (Mexico); Chernov, V; Barboza F, M [Departamento de Investigacion en Fisica, Universidad de Sonora, Hermosillo (Mexico)

    2002-07-01

    The gamma radiation has been used in several places of the World as a sterilization method, preservation and pasteurization of foodstuffs, effect which is achieved due to diminishing or elimination of the microorganisms, reaching every time more acceptance, moreover eliminates the uses of toxic and carcinogenic substances, of general use, but at the present, being in the process of being totally prohibited, due to the higher risk in the human health. In this work the related results with the effects of the gamma radiation are presented, coming from a {sup 60} Co source, in commercial wheat flour exposed to a dose of 1.0 KGy. The used dose is that allowed according to the NOM-033-SSA1-1993 standard. It was determined that the chemical characteristics of humidity, protein and ashes were not affected by radiation. The rheological properties neither suffer severe effects as consequence of radiation; the pharynographic and alveographic parameters were lightly affected by the treatment. Significant changes were detected in the percentage of water absorption and in the tolerance index to mixing. However a diminish of 10% in the development time and an increase of 13% in the stability was observed, for the irradiated samples respect to the those samples not irradiated. In relation to the alveograph parameters it was only detected a diminish of 7% in the force parameter (w) without changes in the tenacity/blowing up index ratio (P/L). The fall number diminish 11% indicating a small diminution in viscosity. The bakering properties do not turn out modified by the irradiation treatment finding a specific weight of 4.6 and 4.5 (cm{sup 3}/g) for the control and irradiated samples, respectively. In the mesophyll analysis it was found a diminish of 96% from the original charge in control samples, observing a diminution of 74 and 25% in yeasts and mushrooms respectively. Microbiologically it was determined absence of total coliforms bacteria and faecal coliforms in the control

  5. Yeast Infection Test: MedlinePlus Lab Test Information

    Science.gov (United States)

    ... cheese-like discharge Painful urination Redness in the vagina Yeast infection of the penis may cause: Redness Scaling Rash ... on the location of your symptoms: If a vaginal yeast infection is suspected , your health care provider will perform ...

  6. 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.

  7. Characterization of wine yeasts for ethanol production

    Energy Technology Data Exchange (ETDEWEB)

    Jimenez, J.; Benitez, T.

    1986-11-01

    Selected wine yeasts were tested for their ethanol and sugar tolerance, and for their fermentative capacity. Growth (..mu..) and fermentation rates (..nu..) were increasingly inhibited by increasing ethanol and glucose concentrations, ''flor'' yeasts being the least inhibited. Except in the latter strains, the ethanol production rate was accelerated by adding the glucose stepwise. The best fermenting strains selected in laboratory medium were also the best at fermenting molasses. Invertase activity was not a limiting step in ethanol production, ..nu.. being accelerated by supplementing molasses with ammonia and biotine, and by cell recycle.

  8. 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.

  9. Guidelines and recommendations on yeast cell death nomenclature

    OpenAIRE

    Carmona-Gutierrez, Didac; Bauer, Maria Anna; Zimmermann, Andreas; Aguilera, Andres; Austriaco, Nicanor; Sigrist, Stephan J.

    2018-01-01

    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 mor...

  10. 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 ...

  11. Guidelines and recommendations on yeast cell death nomenclature

    NARCIS (Netherlands)

    Carmona-Gutierrez, Didac; Bauer, Maria Anna; Zimmermann, Andreas; Aguilera, Andrés; Austriaco, Nicanor; Ayscough, Kathryn; Balzan, Rena; Bar-Nun, Shoshana; Barrientos, Antonio; Belenky, Peter; Blondel, Marc; Braun, Ralf J; Breitenbach, Michael; Burhans, William C; Büttner, Sabrina; Cavalieri, Duccio; Chang, Michael; Cooper, Katrina F; Côrte-Real, Manuela; Costa, Vítor; Cullin, Christophe; Dawes, Ian; Dengjel, Jörn; Dickman, Martin B; Eisenberg, Tobias; Fahrenkrog, Birthe; Fasel, Nicolas; Fröhlich, Kai-Uwe; Gargouri, Ali; Giannattasio, Sergio; Goffrini, Paola; Gourlay, Campbell W; Grant, Chris M; Greenwood, Michael T; Guaragnella, Nicoletta; Heger, Thomas; Heinisch, Jürgen; Herker, Eva; Herrmann, Johannes M; Hofer, Sebastian; Jiménez-Ruiz, Antonio; Jungwirth, Helmut; Kainz, Katharina; Kontoyiannis, Dimitrios P; Ludovico, Paula; Manon, Stéphen; Martegani, Enzo; Mazzoni, Cristina; Megeney, Lynn A; Meisinger, Chris; Nielsen, Jens; Nyström, Thomas; Osiewacz, Heinz D; Outeiro, Tiago F; Park, Hay-Oak; Pendl, Tobias; Petranovic, Dina; Picot, Stephane; Polčic, Peter; Powers, Ted; Ramsdale, Mark; Rinnerthaler, Mark; Rockenfeller, Patrick; Ruckenstuhl, Christoph; Schaffrath, Raffael; Segovia, Maria; Severin, Fedor F; Sharon, Amir; Sigrist, Stephan J; Sommer-Ruck, Cornelia; Sousa, Maria João; Thevelein, Johan M; Thevissen, Karin; Titorenko, Vladimir; Toledano, Michel B; Tuite, Mick; Vögtle, F-Nora; Westermann, Benedikt; Winderickx, Joris; Wissing, Silke; Wölfl, Stefan; Zhang, Zhaojie J; Zhao, Richard Y; Zhou, Bing; Galluzzi, Lorenzo; Kroemer, Guido; Madeo, Frank

    2018-01-01

    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 cel-lular demise. However, the investigation of yeast cell death is a relatively young field, and a widely

  12. Selection of oleaginous yeasts for fatty acid production

    NARCIS (Netherlands)

    Lamers, Dennis; Biezen, van Nick; Martens, Dirk; Peters, Linda; Zilver, van de Eric; Jacobs-van Dreumel, Nicole; Wijffels, René H.; Lokman, Christien

    2016-01-01

    Background: Oleaginous yeast species are an alternative for the production of lipids or triacylglycerides (TAGs). These yeasts are usually non-pathogenic and able to store TAGs ranging from 20 % to 70 % of their cell mass depending on culture conditions. TAGs originating from oleaginous yeasts

  13. Triacetic acid lactone production in industrial Saccharomyces yeast strains

    Science.gov (United States)

    Triacetic acid lactone (TAL) is a potential platform chemical that can be produced in yeast. To evaluate the potential for industrial yeast strains to produce TAL, the g2ps1 gene encoding 2-pyrone synthase was transformed into thirteen industrial yeast strains of varied genetic background. TAL produ...

  14. 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...

  15. Volcanic Risk Perception and Preparedness in Communities within the Mount Baker and Glacier Peak Lahar Hazard Zones

    Science.gov (United States)

    Corwin, K.; Brand, B. D.

    2014-12-01

    A community's ability to effectively respond to and recover from natural hazards depends on both the physical characteristics of the hazard and the community's inherent resilience. Resilience is shaped by a number of factors including the residents' perception of and preparedness for a natural hazard as well as the level of institutional preparedness. This study examines perception of and preparedness for lahar hazards from Mount Baker and Glacier Peak in Washington's Skagit Valley. Through an online survey, this study isolates the influence of specific variables (e.g., knowledge, past experience, scientific background, trust in various information sources, occupation, self-efficacy, sense of community) on risk perception and explores reasons behind the frequent disconnect between perception and preparedness. We anticipate that individuals with more extensive education in the sciences, especially geology or earth science, foster greater trust in scientists and a more accurate knowledge, understanding, and perception of the volcanic hazards in their community. Additionally, little research exists examining the extent to which first responders and leaders in response-related institutions prepare on a personal level. Since these individuals work toward community preparedness professionally, we hypothesize that they will be more prepared at home than members of the general public. Finally, the Skagit Valley has a significant history of flooding. We expect that the need to respond to and recover from frequent flooding creates a community with an inherently higher level of preparedness for other hazards such as lahars. The results of this study will contribute to the understanding of what controls risk perception and the interplay between perception and preparedness. At a broader level, this study provides local and state-level emergency managers information to evaluate and improve response capabilities and communication with the public and key institutions in order to

  16. Preparing for Volcanic Hazards: An Examination of Lahar Knowledge, Risk Perception, and Preparedness around Mount Baker and Glacier Peak, WA

    Science.gov (United States)

    Corwin, K.; Brand, B. D.

    2015-12-01

    As the number of people living at risk from volcanic hazards in the U.S. Pacific Northwest continues to rise, so does the need for improved hazard science, mitigation, and response planning. The effectiveness of these efforts relies not only on scientists and policymakers, but on individuals and their risk perception and preparedness levels. This study examines the individual knowledge, perception, and preparedness of over 500 survey respondents living or working within the lahar zones of Mount Baker and Glacier Peak volcanoes. We (1) explore the common disconnect between accurate risk perception and adequate preparedness; (2) determine how participation in hazard response planning influences knowledge, risk perception, and preparedness; and (3) assess the effectiveness of current lahar hazard maps for public risk communication. Results indicate that a disconnect exists between perception and preparedness for the majority of respondents. While 82% of respondents accurately anticipate that future volcanic hazards will impact the Skagit Valley, this knowledge fails to motivate increased preparedness. A majority of respondents also feel "very responsible" for their own protection and provision of resources during a hazardous event (83%) and believe they have the knowledge and skills necessary to respond effectively to such an event (56%); however, many of these individuals still do not adequately prepare. When asked what barriers prevent them from preparing, respondents primarily cite a lack of knowledge about relevant local hazards. Results show that participation in response-related activities—a commonly recommended solution to this disconnect—minimally influences preparedness. Additionally, although local hazard maps successfully communicate the primary hazard—97% of respondents recognize the lahar hazard—many individuals incorrectly interpret other important facets of the maps. Those who participate in response-related activities fail to understand these

  17. Diversity and genetic structure of the Mexican endemic epiphyte Tillandsia achyrostachys E. Morr. ex Baker var. achyrostachys (Bromeliaceae).

    Science.gov (United States)

    González-Astorga, Jorge; Cruz-Angón, Andrea; Flores-Palacios, Alejandro; Vovides, Andrew P

    2004-10-01

    The monoecious, bird-pollinated epiphytic Tillandsia achyrostachys E. Morr. ex Baker var. achyrostachys is an endemic bromeliad of the tropical dry forests of Mexico with clonal growth. In the Sierra de Huautla Natural Reserve this species shows a host preference for Bursera copallifera (Sessé & Moc ex. DC) Bullock. As a result of deforestation in the study area, B. copallifera has become a rare tree species in the remaining forest patches. This human-induced disturbance has directly affected the population densities of T. achyrostachys. In this study the genetic consequences of habitat fragmentation were assessed by comparing the genetic diversity, gene flow and genetic differentiation in six populations of T. achyrostachys in the Sierra de Huautla Natural Reserve, Mexico. Allozyme electrophoresis of sixteen loci (eleven polymorphic and five monomorphic) were used. The data were analysed with standard statistical approximations for obtaining diversity, genetic structure and gene flow. Genetic diversity and allelic richness were: HE = 0.21 +/- 0.02, A = 1.86 +/- 0.08, respectively. F-statistics revealed a deficiency of heterozygous plants in all populations (Fit = 0.65 +/- 0.02 and Fis = 0.43 +/- 0.06). Significant genetic differentiation between populations was detected (Fst = 0.39 +/- 0.07). Average gene flow between pairs of populations was relatively low and had high variation (Nm = 0.46 +/- 0.21), which denotes a pattern of isolation by distance. The genetic structure of populations of T. achyrostachys suggests that habitat fragmentation has reduced allelic richness and genetic diversity, and increased significant genetic differentiation (by approx. 40 %) between populations. The F-statistic values (>0) and the level of gene flow found suggest that habitat fragmentation has broken up the former population structure. In this context, it is proposed that the host trees of T. achyrostachys should be considered as a conservation priority, since they represent the

  18. 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

  19. Yeast mother cell-specific aging

    Czech Academy of Sciences Publication Activity Database

    Breitenbach, M.; Laun, P.; Pichová, Alena; Madeo, F.; Heeren, G.; Kohlwein, S. D.; Froehlich, K. U.; Dawes, I.

    2001-01-01

    Roč. 18, - (2001), s. 21 ISSN 0749-503X. [International Conference on Yeast Genetics and Molecular Biology /20./. 26.08.2001-31.08.2001, Prague] Institutional research plan: CEZ:AV0Z5020903 Subject RIV: EB - Genetics ; Molecular Biology

  20. Xylitol production from colombian native yeast strains

    Directory of Open Access Journals (Sweden)

    Isleny Andrea Vanegas Córdoba

    2004-07-01

    Full Text Available Xylitol is an alternative sweetener with similar characteristics to sucrose that has become of great interest, due mainly to its safe use in diabetic patients and those deficient in glucose-6-phosphate-dehydrogenase. Its chemical production is expensive and generates undesirable by-products, whereas biotechnological process, which uses different yeasts genera, is a viable production alternative because it is safer and specific. Colombia has a privilege geographic location and offers a great microbial variety, this can be taken advantage of with academic and commercial goals. Because of this, some native microorganisms with potential to produce xylitol were screened in this work. It were isolated 25 yeasts species, from which was possible to identify 84% by the kit API 20C-AUX. Three yeasts: Candida kefyr, C. tropicalis y C. parapsilosis presented greater capacity to degrade xylose compared to the others, therefore they were selected for the later evaluation of its productive capacity. Discontinuous cellular cultures were developed in shaken flasks at 200 rpm and 35°C by 30 hours, using synthetic media with xylose as carbon source. Xylose consumption and xylitol production were evaluated by thin layer chromatography and high performance liquid chromatography. The maximal efficiency were obtained with Candida kefyr and C. tropicalis (Yp/s 0.5 y 0.43 g/g, respectively, using an initial xylose concentration of 20 g/L. Key words: Xylitol, xylose, yeasts, Candida kefyr, C. tropicalis, C. parapsilosis.

  1. 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...

  2. 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

  3. Ethanol fermentation with a flocculating yeast

    Energy Technology Data Exchange (ETDEWEB)

    Admassu, W; Korus, R A; Heimsch, R C

    1985-08-01

    A 100 cm x 5.7 cm internal diameter tower fermentor was fabricated and operated continuously for 11 months using the floc-forming yeast, Saccharomyces cerevisiae (American Type Culture Collection 4097). Steady state operation of the system was characterized at 32/sup 0/C and pH 4.0 for glucose concentrations ranging from 105 to 215 g l/sup -1/. The height of the yeast bed in the tower was maintained at 80 cm. The high yeast density, ethanol concentration and low pH prevented bacterial contamination in the reactor. The concentration profiles of glucose and ethanol within the bed were described by a dispersion model. Modeling parameters were determined for the yeast by batch kinetics and tracer experiments. The kinetic model included ethanol inhibition and substrate limitation. A tracer study with step input of D-xylose (a non-metabolizable sugar for S. cerevisiae) determined the dispersion number (D/uL=0.16) and liquid voidage (epsilonsub(L)=0.25). Measurements taken after 6 months of continuous operation indicated that there was no significant change in fermentor performance.

  4. 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....

  5. 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...

  6. 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 ...

  7. 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...

  8. Catalytic site interactions in yeast OMP synthase

    DEFF Research Database (Denmark)

    Hansen, Michael Riis; Barr, Eric W.; Jensen, Kaj Frank

    2014-01-01

    45 (2006) 5330-5342]. This behavior was investigated in the yeast enzyme by mutations in the conserved catalytic loop and 5-phosphoribosyl-1-diphosphate (PRPP) binding motif. Although the reaction is mechanistically sequential, the wild-type (WT) enzyme shows parallel lines in double reciprocal...

  9. 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 ...

  10. 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

  11. 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...

  12. Yeast cell differentiation: Lessons from pathogenic and non-pathogenic yeasts.

    Science.gov (United States)

    Palková, Zdena; Váchová, Libuše

    2016-09-01

    Yeasts, historically considered to be single-cell organisms, are able to activate different differentiation processes. Individual yeast cells can change their life-styles by processes of phenotypic switching such as the switch from yeast-shaped cells to filamentous cells (pseudohyphae or true hyphae) and the transition among opaque, white and gray cell-types. Yeasts can also create organized multicellular structures such as colonies and biofilms, and the latter are often observed as contaminants on surfaces in industry and medical care and are formed during infections of the human body. Multicellular structures are formed mostly of stationary-phase or slow-growing cells that diversify into specific cell subpopulations that have unique metabolic properties and can fulfill specific tasks. In addition to the development of multiple protective mechanisms, processes of metabolic reprogramming that reflect a changed environment help differentiated individual cells and/or community cell constituents to survive harmful environmental attacks and/or to escape the host immune system. This review aims to provide an overview of differentiation processes so far identified in individual yeast cells as well as in multicellular communities of yeast pathogens of the Candida and Cryptococcus spp. and the Candida albicans close relative, Saccharomyces cerevisiae. Molecular mechanisms and extracellular signals potentially involved in differentiation processes are also briefly mentioned. Copyright © 2016 Elsevier Ltd. All rights reserved.

  13. Full Data of Yeast Interacting Proteins Database (Original Version) - Yeast Interacting Proteins Database | LSDB Archive [Life Science Database Archive metadata

    Lifescience Database Archive (English)

    Full Text Available List Contact us Yeast Interacting Proteins Database Full Data of Yeast Interacting Proteins Database (Origin...al Version) Data detail Data name Full Data of Yeast Interacting Proteins Database (Original Version) DOI 10....18908/lsdba.nbdc00742-004 Description of data contents The entire data in the Yeast Interacting Proteins Database...eir interactions are required. Several sources including YPD (Yeast Proteome Database, Costanzo, M. C., Hoga...ematic name in the SGD (Saccharomyces Genome Database; http://www.yeastgenome.org /). Bait gene name The gen

  14. Yeast Biodiversity from DOQ Priorat Uninoculated Fermentations.

    Science.gov (United States)

    Padilla, Beatriz; García-Fernández, David; González, Beatriz; Izidoro, Iara; Esteve-Zarzoso, Braulio; Beltran, Gemma; Mas, Albert

    2016-01-01

    Climate, soil, and grape varieties are the primary characteristics of terroir and lead to the definition of various appellations of origin. However, the microbiota associated with grapes are also affected by these conditions and can leave a footprint in a wine that will be part of the characteristics of terroir. Thus, a description of the yeast microbiota within a vineyard is of interest not only to provide a better understanding of the winemaking process, but also to understand the source of microorganisms that maintain a microbial footprint in wine from the examined vineyard. In this study, two typical grape varieties, Grenache and Carignan, have been sampled from four different vineyards in the DOQ Priorat winegrowing region. Afterward, eight spontaneous alcoholic fermentations containing only grapes from one sampling point and of one variety were conducted at laboratory scale. The fermentation kinetics and yeast population dynamics within each fermentation experiment were evaluated. Yeast identification was performed by RFLP-PCR of the 5.8S-ITS region and by sequencing D1/D2 of the 26S rRNA gene of the isolates. The fermentation kinetics did not indicate clear differences between the two varieties of grapes or among vineyards. Approximately 1,400 isolates were identified, exhibiting high species richness in some fermentations. Of all the isolates studied, approximately 60% belong to the genus Hanseniaspora, 16% to Saccharomyces, and 11% to Candida. Other minor genera, such as Hansenula, Issatchenkia, Kluyveromyces, Saccharomycodes, and Zygosaccharomyces, were also found. The distribution of the identified yeast throughout the fermentation process was studied, and Saccharomyces cerevisiae was found to be present mainly at the end of the fermentation process, while Aureobasidium pullulans was isolated primarily during the first days of fermentation in three of the eight spontaneous fermentations. This work highlights the complexity and diversity of the vineyard

  15. Game dynamic model for yeast development.

    Science.gov (United States)

    Huang, Yuanyuan; Wu, Zhijun

    2012-07-01

    Game theoretic models, along with replicator equations, have been applied successfully to the study of evolution of populations of competing species, including the growth of a population, the reaching of the population to an equilibrium state, and the evolutionary stability of the state. In this paper, we analyze a game model proposed by Gore et al. (Nature 456:253-256, 2009) in their recent study on the co-development of two mixed yeast strains. We examine the mathematical properties of this model with varying experimental parameters. We simulate the growths of the yeast strains and compare them with the experimental results. We also compute and analyze the equilibrium state of the system and prove that it is asymptotically and evolutionarily stable.

  16. Mapping replication origins in yeast chromosomes.

    Science.gov (United States)

    Brewer, B J; Fangman, W L

    1991-07-01

    The replicon hypothesis, first proposed in 1963 by Jacob and Brenner, states that DNA replication is controlled at sites called origins. Replication origins have been well studied in prokaryotes. However, the study of eukaryotic chromosomal origins has lagged behind, because until recently there has been no method for reliably determining the identity and location of origins from eukaryotic chromosomes. Here, we review a technique we developed with the yeast Saccharomyces cerevisiae that allows both the mapping of replication origins and an assessment of their activity. Two-dimensional agarose gel electrophoresis and Southern hybridization with total genomic DNA are used to determine whether a particular restriction fragment acquires the branched structure diagnostic of replication initiation. The technique has been used to localize origins in yeast chromosomes and assess their initiation efficiency. In some cases, origin activation is dependent upon the surrounding context. The technique is also being applied to a variety of eukaryotic organisms.

  17. Stochasticity in the yeast mating pathway

    International Nuclear Information System (INIS)

    Hong-Li, Wang; Zheng-Ping, Fu; Xin-Hang, Xu; Qi, Ouyang

    2009-01-01

    We report stochastic simulations of the yeast mating signal transduction pathway. The effects of intrinsic and external noise, the influence of cell-to-cell difference in the pathway capacity, and noise propagation in the pathway have been examined. The stochastic temporal behaviour of the pathway is found to be robust to the influence of inherent fluctuations, and intrinsic noise propagates in the pathway in a uniform pattern when the yeasts are treated with pheromones of different stimulus strengths and of varied fluctuations. In agreement with recent experimental findings, extrinsic noise is found to play a more prominent role than intrinsic noise in the variability of proteins. The occurrence frequency for the reactions in the pathway are also examined and a more compact network is obtained by dropping most of the reactions of least occurrence

  18. [Invasive yeast infections in neutropenic patients].

    Science.gov (United States)

    Ruiz Camps, Isabel; Jarque, Isidro

    2016-01-01

    Invasive fungal diseases caused by yeasts still play an important role in the morbidity and mortality in neutropenic patients with haematological malignancies. Although the overall incidence of invasive candidiasis has decreased due to widespread use of antifungal prophylaxis, the incidence of non-Candida albicans Candida species is increasing compared with that of C.albicans, and mortality of invasive candidiasis continues to be high. In addition, there has been an increase in invasive infections caused by an array of uncommon yeasts, including species of the genus Malassezia, Rhodotorula, Trichosporon and Saprochaete, characterised by their resistance to echinocandins and poor prognosis. Copyright © 2016 Asociación Española de Micología. Publicado por Elsevier España, S.L.U. All rights reserved.

  19. Isolation and characterization of phenol degrading yeast.

    Science.gov (United States)

    Patel, Riddhi; Rajkumar, Shalini

    2009-04-01

    A phenol degrading yeast isolate was identified and characterized from the soil sample collected from a landfill site, in Ahmedabad, India, by plating the soil dilutions on Sabouraud's Dextrose Agar. The microscopic studies and biochemical tests indicated the isolate to be Saccharomyces cerevisiae. The phenol degrading potential of the isolate was measured by inoculation of pure culture in the mineral medium containing various phenol concentrations ranging from 100 to 800 mg l(-1 )and monitoring phenol disappearance rate at regular intervals of time. Growth of the isolate in mineral medium with various phenol concentrations was monitored by measuring the turbidity (OD(600) nm). The results showed that the isolated yeast was tolerant to phenol up to 800 mg(-1). The phenol degradation ranged from 8.57 to 100% for the concentration of phenol from 800 mg l(-1 )to 200 mg l(-1), respectively. ((c) 2009 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim).

  20. In vivo antihypertensive and antidyslipidemic effects of the crude extracts and fractions of Moringa stenopetala (Baker f. Cufod. leaves in rats.

    Directory of Open Access Journals (Sweden)

    Bekesho eGeleta

    2016-04-01

    Full Text Available Moringa stenopetala (Baker f. Cufod. is a medicinal plant that has been used in Ethiopian traditional medicine as a remedy for treatment of hypertension and diabetes. The aim of this study was to evaluate antihypertensive and antihyperlipidemic effect in fructose induced hypertensive rats.Rats were randomly divided into control and treatment groups (n=6. Treatment groups were given daily extracts (250, 500, and 1000 mg/kg orally with fructose. Whereas, positive, negative and normal control groups were received captopril (20 mg/kg/day with fructose, only fructose (66% w/v ad libitum and distilled water ad libitum for 15 days, respectively. The blood pressure was measured every 5th day using tail cuff blood pressure analyzer, and on the 16th day the blood was sampled to evaluate antihyperlipidemic effect using clinical chemistry analyzer. The study showed that aqueous and 70% ethanol extracts significantly prevented blood pressure increment in a dose dependent manner comparable to that of the standard drug. Similarly, the extracts suppressed increment in lipid profile (cholesterol, glucose and triglycerides compared with negative control. The biochemical test revealed that extracts produced a rise in liver but no effect on kidney function indicators compared with normal control.These findings revealed that both crude extracts of Moringa stenopetala (Baker f. Cufod. possess antihypertensive and antihyperlipidemic effect.

  1. 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.

  2. 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.

  3. Phyllosphere yeasts rapidly break down biodegradable plastics

    OpenAIRE

    Kitamoto, Hiroko K; Shinozaki, Yukiko; Cao, Xiao-hong; Morita, Tomotake; Konishi, Masaaki; Tago, Kanako; Kajiwara, Hideyuki; Koitabashi, Motoo; Yoshida, Shigenobu; Watanabe, Takashi; Sameshima-Yamashita, Yuka; Nakajima-Kambe, Toshiaki; Tsushima, Seiya

    2011-01-01

    The use of biodegradable plastics can reduce the accumulation of environmentally persistent plastic wastes. The rate of degradation of biodegradable plastics depends on environmental conditions and is highly variable. Techniques for achieving more consistent degradation are needed. However, only a few microorganisms involved in the degradation process have been isolated so far from the environment. Here, we show that Pseudozyma spp. yeasts, which are common in the phyllosphere and are easily ...

  4. 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.

  5. 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...

  6. Environmental influences on organotin-yeast interactions

    OpenAIRE

    White, Jane S.

    2002-01-01

    As a consequence of the widespread industrial and agricultural applications of organotin compounds, contamination of various ecosystems has occurred in recent decades. Understanding how these compounds interact with cellular membranes is essential in assessing the risks of organotin pollution. The organotins, tributyltin (TBT) and trimethyltin (TMT) and inorganic tin, Sn(IV), were investigated for their physical interactions with non-metabolising cells and protoplasts of the yeast, Candida ma...

  7. Beneficial properties of probiotic yeast Saccharomyces boulardii

    OpenAIRE

    Tomičić Zorica M.; Čolović Radmilo R.; Čabarkapa Ivana S.; Vukmirović Đuro M.; Đuragić Olivera M.; Tomičić Ružica M.

    2016-01-01

    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 th...

  8. Taxonomy Icon Data: fission yeast [Taxonomy Icon

    Lifescience Database Archive (English)

    Full Text Available fission yeast Schizosaccharomyces pombe Schizosaccharomyces_pombe_L.png Schizosaccharomyce...s_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=Schizosaccharomyce...s+pombe&t=NL http://biosciencedbc.jp/taxonomy_icon/icon.cgi?i=Schizosaccharomyce...s+pombe&t=S http://biosciencedbc.jp/taxonomy_icon/icon.cgi?i=Schizosaccharomyces+pombe&t=NS

  9. Pentose utilization in yeasts: Physiology and biochemistry

    Energy Technology Data Exchange (ETDEWEB)

    Jeppson, H.

    1996-04-01

    The fermentive performance of bacteria, yeasts, and filamentous fungi was investigated in a pentose (xylose)-rich lignocellulosic hydrolyzate. The filamentous fungus Fusarium oxysporum and the xylose-fermenting yeast Pichia stipitis were found to be very sensitive to the inhibiting hydrolyzate. Recombinant xylose-utilizing Saccharomyces cerevisiae showed very poor ethanol formation from xylose; xylitol being the major product formed. The highest ethanol yields were obtained with recombinant Escherichia coli KO11, however, for maximal ethanol yield detoxification of the hydrolyzate was required. The influence of oxygen on the regulation of carbohydrate metabolism in the xylose-fermenting yeast P. stipitis CBS 6054 was investigated. A low and well-controlled level of oxygenation has been found to be required for efficient ethanol formation from xylose by the xylose-fermenting yeasts. The requirement of oxygen is frequently ascribed to the apparent redox imbalance which develops under anaerobic conditions due to the difference in co-factor utilization of the two first enzymes in the xylose metabolism, further reflected in xylitol excretion. However, a low and well controlled level of oxygenation for maximal ethanol production from glucose was also demonstrated, suggesting that the oxygen requirement is not only due to the dual co-factor utilization, but also serves other purposes. Cyanide-insensitive and salicyl hydroxamic acid-sensitive respiration (CIR) was found in P. stipitis. CIR is suggested to act as a redox sink preventing xylitol formation in P. stipitis under oxygen-limited xylose fermentations. Xylitol metabolism by P. stipitis CBS 6054 was strictly respiratory and ethanol was not formed under any conditions. The absence of ethanol formation was not due to a lack of fermentative enzymes, since the addition of glucose to xylitol-pregrown cells resulted in ethanol formation. 277 refs, 5 figs, 7 tabs

  10. Yeast Biodiversity from DOQ Priorat Uninoculated Fermentations

    OpenAIRE

    Padilla, Beatriz; Garc?a-Fern?ndez, David; Gonz?lez, Beatriz; Izidoro, Iara; Esteve-Zarzoso, Braulio; Beltran, Gemma; Mas, Albert

    2016-01-01

    Climate, soil, and grape varieties are the primary characteristics of terroir and lead to the definition of various appellations of origin. However, the microbiota associated with grapes are also affected by these conditions and can leave a footprint in a wine that will be part of the characteristics of terroir. Thus, a description of the yeast microbiota within a vineyard is of interest not only to provide a better understanding of the winemaking process, but also to understand the source of...

  11. Raman Microspectroscopy of the Yeast Vacuoles

    Czech Academy of Sciences Publication Activity Database

    Bednárová, Lucie; Palacký, J.; Bauerová, Václava; Hrušková-Heidingsfeldová, Olga; Pichová, Iva; Mojzeš, P.

    2012-01-01

    Roč. 27, 5-6 (2012), s. 503-507 ISSN 0712-4813 R&D Projects: GA ČR GAP208/10/0376; GA ČR GA310/09/1945 Institutional research plan: CEZ:AV0Z40550506 Keywords : Raman microspectroscopy * living cell * yeast * vacuole * chemical composition * polyphospate * Candida albicans Subject RIV: CE - Biochemistry Impact factor: 0.530, year: 2012

  12. Development of Industrial Yeast Platform Strains

    DEFF Research Database (Denmark)

    Bergdahl, Basti; Dato, Laura; Förster, Jochen

    2014-01-01

    Most of the current metabolic engineering projects are carried out using laboratory strains as the starting host. Although such strains are easily manipulated genetically, their robustness does not always meet the requirements set by industrial fermentation conditions. In such conditions, the cells...... screening of the 36 industrial and laboratory yeast strains. In addition, progress in the development of molecular biology methods for generating the new strains will be presented....

  13. 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......: 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....

  14. Enzymes of Candida tropicalis yeast biodegrading phenol

    OpenAIRE

    Koubková, Zuzana

    2011-01-01

    Effluents of industrial wastewaters from oil refineries, paper mills, dyes, ceramic factories, resins, textiles and plastic contain high concentrations of aromatic compounds, which are toxic to organisms. Degradation of these compounds to tolerant limits before releasing them into the environment is an urgent requirement. Candida tropicalis yeast is an important representative of eucaryotic microorganisms that are able to utilize phenol. During the first phase of phenol biodegradation, cytopl...

  15. 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

  16. In situ rheology of yeast biofilms.

    Science.gov (United States)

    Brugnoni, Lorena I; Tarifa, María C; Lozano, Jorge E; Genovese, Diego

    2014-01-01

    The aim of the present work was to investigate the in situ rheological behavior of yeast biofilms growing on stainless steel under static and turbulent flow. The species used (Rhodototula mucilaginosa, Candida krusei, Candida kefyr and Candida tropicalis) were isolated from a clarified apple juice industry. The flow conditions impacted biofilm composition over time, with a predominance of C. krusei under static and turbulent flow. Likewise, structural variations occurred, with a tighter appearance under dynamic flow. Under turbulent flow there was an increase of 112 μm in biofilm thickness at 11 weeks (p < 0.001) and cell morphology was governed by hyphal structures and rounded cells. Using the in situ growth method introduced here, yeast biofilms were determined to be viscoelastic materials with a predominantly solid-like behavior, and neither this nor the G'0 values were significantly affected by the flow conditions or the growth time, and at large deformations their weak structure collapsed beyond a critical strain of about 1.5-5%. The present work could represent a starting point for developing in situ measurements of yeast rheology and contribute to a thin body of knowledge about fungal biofilm formation.

  17. Determination of Proteinaceous Selenocysteine in Selenized Yeast

    Directory of Open Access Journals (Sweden)

    Katarzyna Bierla

    2018-02-01

    Full Text Available A method for the quantitation of proteinaceous selenocysteine (SeCys in Se-rich yeast was developed. The method is based on the reduction of the Se-Se and S-Se bridges with dithiotretiol, derivatization with iodoacetamide (carbamidomethylation, followed by HPLC-ICP MS. The chromatographic conditions were optimized for the total recovery of the proteinaceous selenocysteine, the minimum number of peaks in the chromatogram (reduction of derivatization products of other Se-species present and the baseline separation. A typical chromatogram of a proteolytic digest of selenized yeast protein consisted of up to five peaks (including SeMet, carbamidomethylated (CAM-SeCys, and Se(CAM2 identified by retention time matching with available standards and electrospray MS. Inorganic selenium non-specifically attached to proteins and selenomethionine could be quantified (in the form of Se(CAM2 along with SeCys. Selenocysteine, selenomethionine, inorganic selenium, and the water soluble-metabolite fraction accounted for the totality of selenium species in Se-rich yeast.

  18. How do yeast sense mitochondrial dysfunction?

    Directory of Open Access Journals (Sweden)

    Dmitry A. Knorre

    2016-09-01

    Full Text Available Apart from energy transformation, mitochondria play important signaling roles. In yeast, mitochondrial signaling relies on several molecular cascades. However, it is not clear how a cell detects a particular mitochondrial malfunction. The problem is that there are many possible manifestations of mitochondrial dysfunction. For example, exposure to the specific antibiotics can either decrease (inhibitors of respiratory chain or increase (inhibitors of ATP-synthase mitochondrial transmembrane potential. Moreover, even in the absence of the dysfunctions, a cell needs feedback from mitochondria to coordinate mitochondrial biogenesis and/or removal by mitophagy during the division cycle. To cope with the complexity, only a limited set of compounds is monitored by yeast cells to estimate mitochondrial functionality. The known examples of such compounds are ATP, reactive oxygen species, intermediates of amino acids synthesis, short peptides, Fe-S clusters and heme, and also the precursor proteins which fail to be imported by mitochondria. On one hand, the levels of these molecules depend not only on mitochondria. On the other hand, these substances are recognized by the cytosolic sensors which transmit the signals to the nucleus leading to general, as opposed to mitochondria-specific, transcriptional response. Therefore, we argue that both ways of mitochondria-to-nucleus communication in yeast are mostly (if not completely unspecific, are mediated by the cytosolic signaling machinery and strongly depend on cellular metabolic state.

  19. Matemaatiline juhtimine / Stephen Baker

    Index Scriptorium Estoniae

    Baker, Stephen

    2008-01-01

    Autori raamat "Numeraadid" tutvustab matemaatikavõlureid, kes tuhnivad meie andmetes. Numeraatide üks paljutõotavamaid laboreid on töökohad, kus saab uurida iga klahvivajutust, hiireklõpsu ja meilisõnumit. Peatükis "Töötajad" vaatleb autor IBMi, kus matemaatikud loovad omaenda kolleegide käitumist prognoosivaid mudeleid. Lisa: Juhtimise teadus. Stopperist matemaatiliste mudeliteni; Viited

  20. 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'.

  1. 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.

  2. 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.

  3. 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 probability of these species to be involved in disease. Slow-growing black yeast-like fungi in routine specimens were prospectively collected and identified. A questionnaire regarding patient information was sent to physicians regarding black yeast-like fungus positive patients. A total of 20 746...... dermatological specimens were examined by culture. Black yeast-like fungi accounted for 2.2% (n = 108) of the positive cultures. Only 31.0% of the samples, culture positive for black yeast-like fungi were direct microscopy positive when compared with overall 68.8% of the culture positive specimens. The most...

  4. 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.

  5. Yeast hulls: effect on spontaneous fermentation in different vinification conditions

    Directory of Open Access Journals (Sweden)

    Rosa López

    2000-09-01

    Full Text Available The effect of the addition of yeast hulls in vinification was investigated during three consecutive years. The study was carried out in the experimental winery of C.I.D.A in La Rioja (Spain with free running white grape juice of the Viura variety. Four different vinifications were studied. In two of these vinifications, stuck fermentations were detected. In all the studies, the addition of yeast hulls (yeast ghosts improved the fermentation kinetics, increasing the number of viable yeasts at the end of the exponential stage and decreasing the final content of reducing sugars. This work revealed a new effect of yeast hull addition which had not been identified previously; their selection effect on the wild yeast strain in spontaneous fermentation.

  6. 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.

  7. Determination of the autolysis of champagne yeast by using 14C-labelled yeast

    International Nuclear Information System (INIS)

    Molnar, I.; Oura, E.; Suomalainen, H.

    1980-01-01

    The degree of autolysis of 14 C-labelled Champagne Hautvillers yeast was studied in the function of different temperatures of storage. A linear relationship was found between the length of the storage and the degree of autolysis. The rate of autolysis increased with raising the temperature of storage. The raising of the temperature by 10 deg C was followed by a 6-7% increase in the rate of autolysis. Shaking up the yeast sediment at 20-day intervals raised the rate of autolysis by 1.5-4.2%. (author)

  8. Determination of the autolysis of champagne yeast by using /sup 14/C-labelled yeast

    Energy Technology Data Exchange (ETDEWEB)

    Molnar, I [Orszagos Szoeleszeti es Boraszati Kutatointezet, Budapest (Hungary); Oura, E; Suomalainen, H [Research Laboratories of the State Alcohol Monopoly, Helsinki (Finland)

    1980-01-01

    The degree of autolysis of /sup 14/C-labelled Champagne Hautvillers yeast was studied in the function of different temperatures of storage. A linear relationship was found between the length of the storage and the degree of autolysis. The rate of autolysis increased with raising the temperature of storage. The raising of the temperature by 10 deg C was followed by a 6-7% increase in the rate of autolysis. Shaking up the yeast sediment at 20-day intervals raised the rate of autolysis by 1.5-4.2%.

  9. Effect of heat treatment on brewer's yeast fermentation activity

    OpenAIRE

    Kharandiuk, Tetiana; Kosiv, Ruslana; Palianytsia, Liubov; Berezovska, Natalia

    2015-01-01

    The influence of temperature treatment of brewer's yeast strain Saflager W-34/70 at temperatures of -17, 20, 25, 30, 35, 40 °C on their fermentative activity was studied. It was established that the freezing of yeast leads to a decrease of fermentation activity in directly proportional to the duration way. Fermentative activity of yeast samples can be increased by 20-24% by heat treatment at 35 °C during 15-30 minutes.

  10. Using Microsatellites to Identify Yeast Strains in Beer

    OpenAIRE

    Bruke, Alexandria; Van Brocklin, Jennifer; Rivest, Jason; Prenni, Jessica E.; Ibrahim, Hend

    2012-01-01

    Yeast is an integral part of the brewing process and is responsible for much of the taste and characteristics of beer. During the brewing process, yeast is subject to ageing and stress factors that can result in growth inhibition, decreased genetic stability, and changes in cell membrane stability. Characterization of yeast species used in industrial fermentation (e.g. S. cerevisiae) is of great importance to the brewing industry. The objective of this study was to develop an assay to identif...

  11. Yeast replicative aging: a paradigm for defining conserved longevity interventions

    OpenAIRE

    Wasko, Brian M.; Kaeberlein, Matt

    2013-01-01

    The finite replicative life span of budding yeast mother cells was demonstrated as early as 1959, but the idea that budding yeast could be used to model aging of multicellular eukaryotes did not enter the scientific mainstream until relatively recently. Despite continued skepticism by some, there are now abundant data that several interventions capable of extending yeast replicative life span have a similar effect in multicellular eukaryotes including nematode worms, fruit flies, and rodents....

  12. Yeast species associated with the spontaneous fermentation of cider.

    OpenAIRE

    Suárez, Belén; Pando, Rosa; Fernández, Norman; Querol, Amparo; Rodríguez, Roberto

    2018-01-01

    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 ...

  13. 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....

  14. Study on ionizing radiosensitivity of respiratory deficiency yeast mutants

    International Nuclear Information System (INIS)

    Mao Shuhong; Chinese Academy of Sciences, Beijing; Jin Genming; Wei Zengquan; Xie Hongmei

    2006-01-01

    The radiosensitivity of respiratory deficiency yeast mutants has been studied in this work. The mutants which were screened from the yeasts after ionizing irradiation were irradiated with 12 C 6+ at different doses. Because of the great change in its mitochondria and mitochondrial DNA, the respiratory deficiency yeast mutants show radio-sensitivity at dose less than 1 Gy and radioresistance at doses higher than 1 Gy. (authors)

  15. 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.

  16. The ecology of the Drosophila-yeast mutualism in wineries

    Science.gov (United States)

    2018-01-01

    The fruit fly, Drosophila melanogaster, is preferentially found on fermenting fruits. The yeasts that dominate the microbial communities of these substrates are the primary food source for developing D. melanogaster larvae, and adult flies manifest a strong olfactory system-mediated attraction for the volatile compounds produced by these yeasts during fermentation. Although most work on this interaction has focused on the standard laboratory yeast Saccharomyces cerevisiae, a wide variety of other yeasts naturally ferment fallen fruit. Here we address the open question of whether D. melanogaster preferentially associates with distinct yeasts in different, closely-related environments. We characterized the spatial and temporal dynamics of Drosophila-associated fungi in Northern California wineries that use organic grapes and natural fermentation using high-throughput, short-amplicon sequencing. We found that there is nonrandom structure in the fungal communities that are vectored by flies both between and within vineyards. Within wineries, the fungal communities associated with flies in cellars, fermentation tanks, and pomace piles are distinguished by varying abundances of a small number of yeast species. To investigate the origins of this structure, we assayed Drosophila attraction to, oviposition on, larval development in, and longevity when consuming the yeasts that distinguish vineyard microhabitats from each other. We found that wild fly lines did not respond differentially to the yeast species that distinguish winery habitats in habitat specific manner. Instead, this subset of yeast shares traits that make them attractive to and ensure their close association with Drosophila. PMID:29768432

  17. 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.

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

    Science.gov (United States)

    Rajgarhia, Vineet [Kingsport, TN; Koivuranta, Kari [Helsinki, FI; Penttila, Merja [Helsinki, FI; Ilmen, Marja [Helsinki, FI; Suominen, Pirkko [Maple Grove, MN; Aristidou, Aristos [Maple Grove, MN; Miller, Christopher Kenneth [Cottage Grove, MN; Olson, Stacey [St. Bonifacius, MN; Ruohonen, Laura [Helsinki, FI

    2011-05-17

    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. 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...n synthase, similar to Gsy1p; expression induced by glucose limitation, nitrogen ...; expression induced by glucose limitation, nitrogen starvation, environmental stress, and entry into statio...ogen synthase, similar to Gsy1p; expression induced by glucose limitation, nitrogen starvation, heat shock,

  20. Yeast cell differentiation: Lessons from pathogenic and non-pathogenic yeasts

    Czech Academy of Sciences Publication Activity Database

    Pálková, Z.; Váchová, Libuše

    2016-01-01

    Roč. 57, SEP (2016), s. 110-119 ISSN 1084-9521 R&D Projects: GA ČR GA13-08605S; GA MŠk(CZ) ED1.1.00/02.0109 Institutional support: RVO:61388971 Keywords : Pathogenic yeasts * Biofilms and colonies * Cell differentiation Subject RIV: EE - Microbiology, Virology Impact factor: 6.614, year: 2016

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

    Energy Technology Data Exchange (ETDEWEB)

    Rajgarhia, Vineet [Kingsport, TN; Koivuranta, Kari [Helsinki, FI; Penttila, Merja [Helsinki, FI; Ilmen, Marja [Helsinki, FI; Suominen, Pirkko [Maple Grove, MN; Aristidou, Aristos [Maple Grove, MN; Miller, Christopher Kenneth [Cottage Grove, MN; Olson, Stacey [St. Bonifacius, MN; Ruohonen, Laura [Helsinki, FI

    2014-01-07

    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 aldose reductase gene(s), deletion of xylitol dehydrogenase gene(s) and/or overexpression of xylulokinase.

  2. 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.

  3. 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.

  4. Genetically modified yeast species and fermentation processes using genetically modified yeast

    Energy Technology Data Exchange (ETDEWEB)

    Rajgarhia, Vineet [Kingsport, TN; Koivuranta, Kari [Helsinki, FI; Penttila, Merja [Helsinki, FI; Ilmen, Marja [Helsinki, FI; Suominen, Pirkko [Maple Grove, MN; Aristidou, Aristos [Maple Grove, MN; Miller, Christopher Kenneth [Cottage Grove, MN; Olson, Stacey [St. Bonifacius, MN; Ruohonen, Laura [Helsinki, FI

    2011-05-17

    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.

  5. 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.

  6. Yeast production from cellulase hydrolyzed furfural industrial waste. II. Conditions for the cultivation of yeast

    Energy Technology Data Exchange (ETDEWEB)

    1977-01-01

    Three yeast strains, Candida AS 2-121, C. utilis AS 2-1180, and C. tropicalis AS 2-637 were selected as being capable of growing on cellulase-hydrolyzed furfural industrial waste. Cell mass yields with respect to C source were approximately 50%. Fermentation conditions are given.

  7. 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

  8. How does yeast respond to pressure?

    Directory of Open Access Journals (Sweden)

    Fernandes P.M.B.

    2005-01-01

    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.

  9. Specificity of transmembrane protein palmitoylation in yeast.

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    Ayelén González Montoro

    Full Text Available Many proteins are modified after their synthesis, by the addition of a lipid molecule to one or more cysteine residues, through a thioester bond. This modification is called S-acylation, and more commonly palmitoylation. This reaction is carried out by a family of enzymes, called palmitoyltransferases (PATs, characterized by the presence of a conserved 50- aminoacids domain called "Asp-His-His-Cys- Cysteine Rich Domain" (DHHC-CRD. There are 7 members of this family in the yeast Saccharomyces cerevisiae, and each of these proteins is thought to be responsible for the palmitoylation of a subset of substrates. Substrate specificity of PATs, however, is not yet fully understood. Several yeast PATs seem to have overlapping specificity, and it has been proposed that the machinery responsible for palmitoylating peripheral membrane proteins in mammalian cells, lacks specificity altogether.Here we investigate the specificity of transmembrane protein palmitoylation in S. cerevisiae, which is carried out predominantly by two PATs, Swf1 and Pfa4. We show that palmitoylation of transmembrane substrates requires dedicated PATs, since other yeast PATs are mostly unable to perform Swf1 or Pfa4 functions, even when overexpressed. Furthermore, we find that Swf1 is highly specific for its substrates, as it is unable to substitute for other PATs. To identify where Swf1 specificity lies, we carried out a bioinformatics survey to identify amino acids responsible for the determination of specificity or Specificity Determination Positions (SDPs and showed experimentally, that mutation of the two best SDP candidates, A145 and K148, results in complete and partial loss of function, respectively. These residues are located within the conserved catalytic DHHC domain suggesting that it could also be involved in the determination of specificity. Finally, we show that modifying the position of the cysteines in Tlg1, a Swf1 substrate, results in lack of palmitoylation, as

  10. Population FBA predicts metabolic phenotypes in yeast.

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    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

  11. Alteration of yeast activity by gamma radiation

    International Nuclear Information System (INIS)

    Chacharkar, M.P.; Tak, B.B.; Bhati, J.

    1996-01-01

    Yeast is an important component in microbe based industrial technologies. Due to the techno-economic reasons, the fermentation technique has acquired renewed interest. The effect of γ-radiation on the fermentation reaction has been investigated. The studies show that exposure of the fermentation mixture to γ-radiation at 5 kGy enhance alcohol production, whereas irradiation at higher doses, viz., 10 kGy and 25 kGy caused a considerable reduction in the alcohol yield. Therefore, low dose irradiation of fermentation mixtures can be applied for increasing the alcohol production by about 25%. (author). 13 refs., 1 fig

  12. Does Probiotic Yeast Act as Antigenotoxin?

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    Jekabs Raipulis

    2005-01-01

    Full Text Available The effect of probiotic yeast Saccharomyces boulardii on genotoxicity induced by the well-known mutagen 4-nitroquinoline-N-oxide (4-NQO, as well as antibacterial (furazolidone and antibiotic (nalidixic acid drugs, has been studied using the short-term bacterial assay, SOS chromotest, with Escherichia coli PQ 37 as the test organism. It has been shown that S. boulardii possesses antigenotoxic activity, revealed by SOS chromotest, when coincubated with these genotoxins. A weaker antigenotoxic activity against the same compounds was observed with S. carlsbergensis, too.

  13. Replication dynamics of the yeast genome.

    Science.gov (United States)

    Raghuraman, M K; Winzeler, E A; Collingwood, D; Hunt, S; Wodicka, L; Conway, A; Lockhart, D J; Davis, R W; Brewer, B J; Fangman, W L

    2001-10-05

    Oligonucleotide microarrays were used to map the detailed topography of chromosome replication in the budding yeast Saccharomyces cerevisiae. The times of replication of thousands of sites across the genome were determined by hybridizing replicated and unreplicated DNAs, isolated at different times in S phase, to the microarrays. Origin activations take place continuously throughout S phase but with most firings near mid-S phase. Rates of replication fork movement vary greatly from region to region in the genome. The two ends of each of the 16 chromosomes are highly correlated in their times of replication. This microarray approach is readily applicable to other organisms, including humans.

  14. Enhancing the performance of brewing yeasts.

    Science.gov (United States)

    Karabín, Marcel; Jelínek, Lukáš; Kotrba, Pavel; Cejnar, Rudolf; Dostálek, Pavel

    2017-12-22

    Beer production is one of the oldest known traditional biotechnological processes, but is nowadays facing increasing demands not only for enhanced product quality, but also for improved production economics. Targeted genetic modification of a yeast strain is one way to increase beer quality and to improve the economics of beer production. In this review we will present current knowledge on traditional approaches for improving brewing strains and for rational metabolic engineering. These research efforts will, in the near future, lead to the development of a wider range of industrial strains that should increase the diversity of commercial beers. Copyright © 2018 Elsevier Inc. All rights reserved.

  15. mRNA processing in yeast

    International Nuclear Information System (INIS)

    Stevens, A.

    1982-01-01

    Investigations in this laboratory center on basic enzymatic reactions of RNA. Still undefined are reactions involved in the conversion of precursors of mRA (pre-mRNA) to mRNA in eukaryotes. The pre-mRNA is called heterogeneous nuclear RNA and is 2 to 6 times larger than mRNA. The conversion, called splicing, involves a removal of internal sequences called introns by endoribonuclease action followed by a rejoining of the 3'- and 5'-end fragments, called exons, by ligating activity. It has not been possible yet to study the enzymes involved in vitro. Also undefined are reactions involved in the turnover or discarding of certain of the pre-mRNA molecules. Yeast is a simple eukaryote and may be expected to have the same, but perhaps simpler, processing reactions as the higher eukaryotes. Two enzymes involved in the processing of pre-mRNA and mRNA in yeast are under investigation. Both enzymes have been partially purified from ribonucleoprotein particles of yeast. The first is a unique decapping enzyme which cleaves [ 3 H]m 7 Gppp [ 14 C]RNA-poly (A) of yeast, yielding [ 3 H]m 7 GDP and is suggested by the finding that the diphosphate product, m 7 GpppA(G), and UDP-glucose are not hydrolyzed. The second enzyme is an endoribonuclease which converts both the [ 3 H] and [ 14 C] labels of [ 3 H]m 7 Gppp[ 14 C]RNA-poly(A) from an oligo(dT)-cellulose bound form to an unbound, acid-insoluble form. Results show that the stimulation involves an interaction of the labeled RNA with the small nuclear RNA. The inhibition of the enzyme by ethidium bromide and its stimulation by small nuclear RNA suggest that it may be a processing ribonuclease, requiring specific double-stranded features in its substrate. The characterization of the unique decapping enzyme and endoribonuclease may help to understand reactions involved in the processing of pre-mRNA and mRNA in eukaryotes

  16. Chromosomal Aneuploidy Improves the Brewing Characteristics of Sake Yeast.

    Science.gov (United States)

    Kadowaki, Masafumi; Fujimaru, Yuki; Taguchi, Seiga; Ferdouse, Jannatul; Sawada, Kazutaka; Kimura, Yuta; Terasawa, Yohei; Agrimi, Gennaro; Anai, Toyoaki; Noguchi, Hideki; Toyoda, Atsushi; Fujiyama, Asao; Akao, Takeshi; Kitagaki, Hiroshi

    2017-12-15

    The effect of chromosomal aneuploidy on the brewing characteristics of brewery yeasts has not been studied. Here we report that chromosomal aneuploidy in sake brewery yeast ( Saccharomyces cerevisiae ) leads to the development of favorable brewing characteristics. We found that pyruvate-underproducing sake yeast, which produces less off-flavor diacetyl, is aneuploid and trisomic for chromosomes XI and XIV. To confirm that this phenotype is due to aneuploidy, we obtained 45 haploids with various chromosomal additions and investigated their brewing profiles. A greater number of chromosomes correlated with a decrease in pyruvate production. Especially, sake yeast haploids with extra chromosomes in addition to chromosome XI produced less pyruvate than euploids. Mitochondrion-related metabolites and intracellular oxygen species in chromosome XI aneuploids were higher than those in euploids, and this effect was canceled in their "petite" strains, suggesting that an increase in chromosomes upregulated mitochondrial activity and decreased pyruvate levels. These findings suggested that an increase in chromosome number, including chromosome XI, in sake yeast haploids leads to pyruvate underproduction through the augmentation of mitochondrial activity. This is the first report proposing that aneuploidy in brewery yeasts improves their brewing profile. IMPORTANCE Chromosomal aneuploidy has not been evaluated in development of sake brewing yeast strains. This study shows the relationship between chromosomal aneuploidy and brewing characteristics of brewery yeast strains. High concentrations of pyruvate during sake storage give rise to α-acetolactate and, in turn, to high concentrations of diacetyl, which is considered an off-flavor. It was demonstrated that pyruvate-underproducing sake yeast is trisomic for chromosome XI and XIV. Furthermore, sake yeast haploids with extra chromosomes produced reduced levels of pyruvate and showed metabolic processes characteristic of

  17. Presencia de Circulifer tenellus Baker y Beet mild curly top virus en maleza durante el invierno en el centro norte de México Circulifer tenellus Baker and Beet mild curly top virus presence in weeds during the winter in north-central Mexico

    OpenAIRE

    Rodolfo Velásquez-Valle; Luis Roberto Reveles-Torres; Mario Domingo Amador-Ramírez; María Mercedes Medina-Aguilar; Guillermo Medina-García

    2012-01-01

    Una de las enfermedades más importantes del chile para secado en el norte centro de México es la denominada amarillamientos del chile. Existe poca información acerca de la interacción entre el vector (Circulifer tenellus Baker), el Beet mild curly top virus y la maleza durante el invierno en esta región, consecuentemente el objetivo del trabajo fue identificar maleza de invierno que sirve como refugio para el vector y hospedero del virus en esta región. Entre enero y marzo de 2011 se muestrea...

  18. Some Metabolites Act as Second Messengers in Yeast Chronological Aging

    Directory of Open Access Journals (Sweden)

    Karamat Mohammad

    2018-03-01

    Full Text Available The concentrations of some key metabolic intermediates play essential roles in regulating the longevity of the chronologically aging yeast Saccharomyces cerevisiae. These key metabolites are detected by certain ligand-specific protein sensors that respond to concentration changes of the key metabolites by altering the efficiencies of longevity-defining cellular processes. The concentrations of the key metabolites that affect yeast chronological aging are controlled spatially and temporally. Here, we analyze mechanisms through which the spatiotemporal dynamics of changes in the concentrations of the key metabolites influence yeast chronological lifespan. Our analysis indicates that a distinct set of metabolites can act as second messengers that define the pace of yeast chronological aging. Molecules that can operate both as intermediates of yeast metabolism and as second messengers of yeast chronological aging include reduced nicotinamide adenine dinucleotide phosphate (NADPH, glycerol, trehalose, hydrogen peroxide, amino acids, sphingolipids, spermidine, hydrogen sulfide, acetic acid, ethanol, free fatty acids, and diacylglycerol. We discuss several properties that these second messengers of yeast chronological aging have in common with second messengers of signal transduction. We outline how these second messengers of yeast chronological aging elicit changes in cell functionality and viability in response to changes in the nutrient, energy, stress, and proliferation status of the cell.

  19. 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

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

    Science.gov (United States)

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

    2014-09-01

    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. © 2014 The Authors. FEMS Microbiology Reviews published by John Wiley & Sons Ltd on behalf of Federation of European Microbiological Societies.